Tag Archives: bone graft

The use of unidirectional porous β-tricarcium phosphate in surgery for calcaneal fractures: A report of four cases

by Shigeo Izawa1*, Toru Funayama2, Masashi Iwasashi1, Toshinori Tsukanishi3, Hiroshi Kumagai2, Hiroshi Noguchi2, Masashi Yamazaki2

The Foot and Ankle Online Journal 10 (4): 2

Affinos@ (Kuraray) is a unidirectional porous β-tricarcium phosphate (UDPTCP). We investigated four patients (four feet) who underwent invasive surgery using UDPTCP to treat calcaneal fractures that were accompanied by a bone defect. The mean age was 63.8±6.4 years old, and the mean observation period was 9.3±3.2 months. We evaluated the changes of UDPTCP over time and correction loss due to its use. In all patients, favorable material absorption and bone substitution were obtained, and their clinical courses were also favorable.

Keywords bone graft , unidirectional porous β-tricarcium phosphate, calcaneus fractures

ISSN 1941-6806
doi: 10.3827/faoj.2017.1004.0002

1 – Department of Orthopedics, Tsukuba Medical Center Hospital. Tsukuba, Japan
2 – Department of Orthopedics, Faculty of Medicine, University of Tsukuba , Japan
3 – Department of Orthopedics, Kenpoku Medical Center Takahagi Kyodo Hospital, Takahagi, Japan
* – Corresponding author: shigeo.izawa.1109@gmail.com


Bone grafting is often required to treat bone fractures that are accompanied by a bone defect. It is apparent that autogenous bone is optimal for bone grafting, but it has disadvantages due to problems with the procedures and quantity of bone graft. Thus, various types of artificial bones have been developed and clinically applied. Affinos@ (Kuraray) is a unidirectional porous β-tricarcium phosphate (UDPTCP) consisting of a novel porous artificial bone with a porosity of 57%, in which communication holes of 25-300 μm are arranged in one direction. It is characterized by balanced artificial bone resorption and replacement of autologous bone [1]. However, only a few clinical outcomes have been reported using this type of UDPTCP. We reported the outcomes of invasive surgeries using UDPTCP in four patients with calcaneus fractures that were accompanied by a bone defect.

Case presentation

Patients and procedures

The subjects were four patients (four feet) who underwent invasive treatments in one of two facilities between February and September 2015. The mean age was 63.8±6.4 years old, and the mean observation period was 9.3±3.2 months. All injuries occurred due to falling accidents, and the radiographic Essex-Lopresti classification was depression type in three patients and tongue type in one patient (Table 1).

During the surgery, a small incision was made on the lateral side of the calcaneus to reduce the fracture area, and a UDPTCP block (two patients) or granules (two patients) was used to fill the bone defect area, depending on its size. A plate (two patients), Steinmann pin (one patient), or K-wire (one patient) was used for internal fixation. The block was installed so that the communication hole was parallel to the load axis. Partial weight bearing was started after 4-6 weeks of non-weight bearing, and full-body weight bearing was allowed at 9-12 weeks.

Plain radiographs were taken before and immediately after the surgery, as well as 1, 3, and 6 months postoperatively to evaluate changes of the UDPTCP and corrective loss over time. The corrective loss was evaluated using the Bohler angle. In one patient in whom granules were used, plain computed tomography (CT) was performed at 3, 6, and 12 months postoperatively to observe the material absorption and bone neogenesis over time in detail.

Case Age

(yr)

Sex Type of fracture Artificial bone Material used for internal fixation
1 67 M Depression type Ⅱ° Block Plate
2 60 M Depression type Ⅲ° Granule Steinmann pin
3 71 F Tongue type Ⅱ° Granule K-wire
4 57 M Depression  type Ⅱ° Block Plate

Table 1 Radiographic Essex-Lopresti classification of each case.

As seen on a plain radiography image, absorption of the UDPTCP progressed within 3 months postoperatively, the majority of the material was absorbed within 6 months postoperatively, and substitution for the bone progressed. On average, the Bohler angle was 5.9° before the operation, 24.5° immediately after, and 21.3° at the final assessment, demonstrating that there was little correction loss after the surgery (Figure 1). Similar changes over time were observed on plain CT images, and the majority of the material had substituted for bone 1 year postoperatively.

Figure 1 Changes of the Bohler angle over time.

Case 1 (Figure 2, 3)

The patient in Case 1 was a 67-year-old man, and he was injured due to falling from a step ladder during pruning work. He underwent surgery 17 days after the injury. The type of fracture was depression type Ⅱ°. The surgical approach was via a lateral skin incision, and the articular surface was reduced by raising the depressed bone fragment. Part of the UDPTCP block was trimmed to the bone defect part, and three blocks were used to fill the defect. Then, plate fixation was performed.

Partial weight bearing was started at 6 weeks postoperatively, and full-body weight bearing was allowed at 10 weeks. During clinical examination, the Bohler angles were as follows: before the surgery: 0°, immediately postoperatively: 25°, and at the final observation (6 months postoperatively): 22°.

After the surgery, no complications occurred, and, as seen on a plain radiography image, artificial bone was absorbed at 3 months postoperatively. In a plain radiography image that was taken 6 months postoperatively, artificial bone was found to have substituted for the natural bone, and the shadow of the artificial bone almost disappeared (Figure 3).

Figure 2 Plain radiography images, from left: at the time of injury, immediately after the surgery, 3 months postoperatively, and 6 months postoperatively.

Figure 3 Plain radiography images (zoom). Left: 3 months postoperatively; Right: 6 months postoperatively.

Case 2 (Figure 4, 5)

The patient in Case 2 was a 60-year-old man who was injured by falling from a truck loading platform. The patient underwent surgery 6 days after the injury. The type of fracture was depression type Ⅲ°.

During the surgery, the approach was via a skin incision, and the articular surface was reduced by raising the depressed bone fragment. The bone defect area was filled with 2 g of UDPTCP granules. Then, a Steinmann pin was inserted from behind.

Partial weight bearing was started at 6 weeks postoperatively, and full-body weight bearing was allowed at 10 weeks. On clinical examination, the Bohler angles were: before the surgery: 1°, immediately after the surgery: 18°, and at final observation (one year postoperatively): 13°.

No complications occurred following the surgery, and the Steinmann pin was removed 6 weeks postoperatively. As seen on a plain CT image one year after the surgery, the artificial bone was almost substituted for the natural bone, and the trabecular structure was located inside it (Figure 5).

Figure 4 A plain radiography image. Left panel: at the time of injury, middle panel: immediately after the surgery, right panel: 6 months after the surgery.

Figure 5 Plain CT images, from left: immediately after the surgery, 3 months after the surgery, 6 months after the surgery, and one year after the surgery.

Discussion

Calcaneal fractures that occur due to falling accidents often result in crushed cancellous bone and bone defects after reduction. Furthermore, bone atrophy and joint contracture occur following long-term non-weight bearing and fixation, complicating the treatment. A biomechanical study by Inoue et al reported that performing bone grafting to treat a calcaneal fracture is useful to maintain repaired bone fragments [2] .  Takai et al.examined the use of β-TCP artificial bone in 5 patients (5 feet) in older patients (aged ≥ 70 years) with calcaneus fractures, and the mean change of the Bohler angle postoperatively was 1°, demonstrating that the procedure has favorable results [3]. Nakagawa et al found that β-TCP has advantages, because it is easy to penetrate β-TCP with a K-wire after grafting [4]. It can also be applied easily in young adults because it can be completely absorbed. However, in some cases, grafted granular β-TCP leaked into the subtalar joint, and was not absorbed even after 1 year or more; therefore, the authors recommended performing grafting with blocked β-TCP instead of granules in patients with comminuted fractures.

Regarding UDPTCP, Makihara et al. used rabbit bone defect models and reported that UDPTCP leads to superior absorption and substitution for autologous bone [1]. In the present study, favorable absorption and bone substitution were confirmed for both UDPTCP block and granules, and no patient had an infection or foreign body reaction, indicating that the postoperative outcomes of the procedure are favorable. Furthermore, the correction loss was small, even after weight bearing was started, suggesting that UDPTCP had sufficient strength to withstand early weight bearing. Regarding the speed of replacement for autogenous bone, a report5) using Osferion (porosity 75%; Olympus), which is a common β-TCP that is used in Japan, showed that, on average, assimilated shadows of the surrounding bone and trabecular bone formation appeared at 8 weeks postoperatively, and the shadow of absorbed artificial bone disappeared at 8 months postoperatively. In our study, absorption of artificial bone was observed at 3 months postoperatively in all cases, and the artificial bone was absorbed almost completely and replaced with autogenous bone at 6 months postoperatively in the earliest case. Although the substitution speed varies depending on the amount and site of grafted artificial bone and the patient’s age, the substitution speed of the UDPTCP was comparable with that of conventional β-TCP, suggesting that UDPTCP is a useful bone filling material in the treatment of calcaneal fracture.

In conclusion, we performed surgery using UDPTCP in patients with calcaneus fractures. In all cases, favorable material absorption and bone substitution were observed, and the clinical outcomes were favorable.

References

  1. Takeshi M. The balance between bone formation and material resorption in unidirectional porous β-tricalcium phosphate implanted in a rabbit tibia. Key Engineering Materials, 696:177-182, 2016.
  2. Nozomu I. The usefulness of combining bone grafts in open surgery of calcaneus fracture. Fracture, 12:173-177, 1990.
  3. Hirokazu T. Open reduction and internal fixation with artificial bone grafts for calcaneus fractures in elderly people. Journal of Orthopedics & Traumatology, 61:765-768, 2012.
  4. Yusuke N. Treatment outcomes of open reduction and fixation using granularβ-TCP by lateral scalpel for intra articular calcaneus fractures. Fracture, 34:446-450, 2012.
  5. Naohiro T. The usefulness of theβ-TCP as bone filling material. Journal of Orthopedics & Traumatology, 63:875-877, 2014.

Clinical and radiological evaluation of unidirectional porous hydroxyapatite (Regenos®) for intra-articular calcaneal fracture with large bone defect

by Akira Ikumi MD1, Masashi Iwasashi MD2, Toshiki Muramatsu MD2, Sayori Li MD2, Mika Hangai MD2, Masataka Sakane MD1pdflrg

The Foot and Ankle Online Journal 7 (2): 5

Background: Although plate-and-screw fixation provides strong support for the surgical treatment of bone fractures, bone reconstruction involving autologous bone or implanted bone substitute materials are promising treatment methods for the repair of large bone defects in areas of poor soft tissues. However, harvesting autologous bone requires invasion and can be associated with donor site morbidity, whereas artificial bone has poor osteoinductive properties and insufficient strength for use in loaded sites. Regenos® is an interconnected porous hydroxyapatite bone substitute that promotes cell penetration and bone formation within the material when implanted into bone defects. This bone substitute also provides strength against loading due to its unidirectional porous structure. Here, we evaluated the potential of Regenos® to repair intra-articular calcaneal fractures.
Methods: In this retrospective study, open reduction of intra-articular calcaneal fractures using Regenos® cubes was evaluated in 4 males (aged 48-73 years). The calcaneal fractures consisted of three joint-depression types and one tongue-type based on Essex-Lopresti classification. The fractures were approached using a single lateral incision and the fractures were reduced under fluoroscopy. The reduction was held with a Kirschner wire (KW) and Steinmann pin (SP) and the bone defects were then filled with Regenos® cubes without plate fixation. All wires and pins were removed four to six weeks after the operation, and partial loading was permitted as part of the postoperative management using a heel brace. Full load bearing was allowed 10 to 12 weeks after the operation. Two-year follow up was obtained for clinical and radiologic outcomes.
Results: Bohler’s angle improved from an average of 1.5 degrees before surgery to 21.5 degrees after surgery, and remained at 20.8 degrees at the time of final evaluation. None of the implanted Regenos® cubes dislocated or collapsed during the evaluation period, and no complications or loss of correction were observed. After 12 weeks, the implants incorporated with the surrounding bone and trabecular bones were reconstructed.
Conclusion: The present clinical findings suggest that Regenos® is useful as a bone graft substitute for filling intra-articular calcaneal fractures treated by open reduction.

Keywords: Bone substitute, bone graft, intra-articular calcaneal fracture, unidirectional pores

ISSN 1941-6806
doi: 10.3827/faoj.2014.0702.0005


Address correspondence to: Akira Ikumi MD
Department of Orthopedics Surgery, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Japan
E-mail: bravelupus193@gmail.com

1 Department of Orthopedics Surgery, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Japan
2 Department of Orthopedics Surgery, Showa General Hospital, Japan


In the treatment of intra-articular calcaneal and tibial plateau fractures, bone defects often remain after fracture reduction, which is typically fixated with plate-and-screw fixation. Although this approach provides strong support, plate fixation is associated with several complications, including infection, revision surgery, hardware failure, and nerve damage.

In addition, autologous bone grafting is often required to retain the articular surface after surgery. The implantation of artificial bone grafts combined with internal fixation has the potential to avoid the possible complications of plate fixation, and may also improve bone strength and clinical outcomes [1].

Materials such as autologous bone, hydroxyapatite (HAp), β-tricalcium phosphate (β-TCP), and calcium phosphate cement (CPC) are commonly used as bone graft materials for filling bone defects. Despite the advantages of artificial materials over autologous bone, patients may suffer from complications such as infection and loss of reduction due to poor osteoconduction and inconsistent incorporation. However, we recently developed a unidirectional, interconnected porous HAp material (Regenos®; Kuraray Co., Ltd.) that promotes the rapid penetration of body fluid and cells into the material through capillary action (Figure 1) [9]. As osteogenic cells easily penetrate into this bone substitute material, bone regeneration and angiogenesis rapidly occur within the implant [3]. We anticipated that the combination of Regenos® implants with fixation through either a Steinmann pin (SP) or Kirschner wire (KW) would promote long-term fracture healing.

In the present study, we retrospectively examined the effectiveness of Regenos® as a bone graft substitute for filling the void space of intra-articular calcaneal fractures during fracture reduction.

Materials and Methods

The medical records of patients who underwent surgical treatment for intra-articular calcaneal fractures at our hospital between December 2010 and June 2011 were retrospectively surveyed and followed-up postoperatively for at least 24 months. The following items were analyzed: age, gender, follow-up duration, fracture type, internal fixation material, and amount of Regenos® used. Bohler’s angle and horizontal diameter ratio of the calcaneus were evaluated using simple X-ray images. Step-off of the posterior talocalcaneal joint surface and the time-course changes of the Regenos® implants were evaluated using computed tomography (CT) images. Time-course changes in the defect area were monitored for 24 to 30 months.

Reg1

Figure 1 Computed tomography image of a cross-section of Regenos® synthetic bone substitute (Kuraray Co., Ltd.).

Patients were evaluated clinically using the Creighton-Nebraska Health Foundation (CNHF) assessment score [7] and fractures were classified as excellent (90 to 100 points), good (80 to 89 points), fair (65 to 79 points), or poor (less than 65 points) (Table 1).

Results

Four male subjects between the ages of 48 and 73 years with intra-articular calcaneal fractures were included in the study. X-ray and CT scans revealed that the fractures consisted of 3 joint-depression type and 1 tongue type by the Essex-Lopresti classification [2], and two Type 2A and two Type 3AB fractures according to the Sanders classification [8].

Surgeries were performed in the decubitus position on the affected side. To access the fracture, the subcutaneous layer at the incision site was moved to allow access to the outer wall of the calcaneus fracture, and the dislocated posterior talocalcaneal joint surface was repositioned. The fracture was fixed from the posterior and distal calcaneus surface using a KW in three patients and a SP in one patient.

RegTable1

Table 1 Characteristics and implant information of the four cases of intra-articular calcaneal fracture.

Reg2

Figure 2 Intra-operative images of a calcaneal fracture repaired using a Regenos® implant. (a) Bone defect after being filled with an implanted Regenos® cube. (b) The implanted cube was oriented parallel to the loading axis. (c) Intra-operative fluoroscopy image taken after the main cube (cylinder type) and some granules were used to fill the defect space after reduction. (d) Regenos® cubes and granules were used to fill the defect space after reduction. (e) Intra-operative fluoroscopy image taken after Regenos® cubes and granules were used to fill the defect space after reduction.

Reg3a Reg3b Reg3c

Figure 3 Time course of changes in the Bohler’s angle (a), calcaneus horizontal diameter ratio (b), and step off of the posterior talocalcaneal joint surface before, immediately, and at the time of last follow-up (24-30 months). The data was obtained from plain x-ray and CT images.

The bone defect which formed after anatomical surface reduction was then filled with Regenos® cubes (10x10x10 mm or 7x7x7 mm). The implanted cubes were placed in the bone so that the direction of the pores was parallel with the load axis. The gaps that remained after implanting the cubes were filled with Regenos® granules (Figure 2). To prevent protrusion of the outer wall of the calcaneus, a fixation staple and cancellous screw were used in one patient.

Six weeks after surgery the KW and SP were removed and partial loading was started as postoperative therapy. Full weight bearing was permitted 12 weeks after surgery. Training for active range of motion of the ankle was started in the first week of the postoperative period. At the time of final evaluation (24 to 30 months), the average CNHF score was 92.8 points (range, 88 to 95 points), and treatment outcome was excellent for 3 patients and good for 1 patient (Table 1).

Time course changes in the following parameters were determined from x-ray and CT images (before surgery/after surgery/final evaluation): Bohler’s angle (average): 1.5 degrees/21.5 degrees/20.8 degrees; calcaneus horizontal diameter ratio (average): 1.29/1.13/1.11; and maximum step-off value of the posterior talocalcaneal joint surface in CT (average): 5.9 mm/2.2 mm/2.3 mm (Figure 3). The contour of the Regenos® cubes in x-ray images was obscured approximately two weeks after surgery. By 6 to 8 weeks after surgery, the implanted cubes appeared denser, indicating that new bone had begun to form within the implanted material. None of the implants were dislocated or crushed during the follow-up period.

To evaluate the effectiveness of Regenos® in intra-articular calcaneal fractures, we examined one case in greater detail (Figure 4). The patient was a 72-year-old man who suffered an intra-articular calcaneal fracture after a 1.5-m fall from a stepladder. The fracture was a tongue type in the Essex-Lopresti classification and Type3AB in the Sanders classification. The preoperative Bohler’s angle was -13 degrees, calcaneus horizontal diameter ratio was 1.4, and posterior talocalcaneal joint step off was 3.9 mm. Surgery was performed on day 11 after the injury.

Reg4

Figure 4 Images of the fracture site before and after surgery for a representative patient. Plain x-ray images at the time of injury (a) and after surgery (b). CT (MPR) images just after surgery (c), 3 months after surgery (d), and 6 months after surgery (e).

Three KWs (2.0-mm diameter) were used for internal fixation. The bone implants consisted of one cylinder type (11 mm x 20 mm), 1 cube type (10x10x10 mm), and 4g of granules. No complications were reported in the postoperative period, and wires were removed six weeks after the surgery. The CNHF score at the final evaluation was 95 points (excellent).

During the follow-up period, no correction loss was observed in the x-ray or CT images. At the time of final evaluation (30 months), the Bohler’s angle was 19 degrees, calcaneus horizontal diameter ratio was 1.08, and posterior talocalcaneal joint step off was 3.0 mm. In an x-ray image of the defect site taken two weeks after surgery, the outline of the Regenos® implants was unclear. The margin of the bone implant became obscure at 6 weeks after surgery, and the implant appeared denser at 8 weeks post-surgery. The contour of individual granules could not be distinguished at 9 weeks after surgery. These findings were confirmed in the CT images. In addition, osteogenesis had occurred in the areas surrounding the granules. After removal of the wires, the bone defect could not be clearly distinguished from the surrounding bone by 6 months after the surgery, and osteogenesis had clearly advanced. During the treatment course, no damage to the cylinder or cube-shaped implants was detected.

Discussion

The use of synthetic bone materials for the repair of large bone defects, such as those that often occur as a result of intra-articular calcaneal fractures, presents a promising treatment option. In four cases, we demonstrated that the interconnected porous HAp bone substitute Regenos® functioned as an effective bone graft substitute for intra-articular calcaneal fracture which contributed to favorable treatment outcomes. At the time of final evaluation (24-30 months), the implanted Regenos® cubes had fused with the surrounding bones, and the trabecular bones were successfully reconstructed. None of the implants dislocated or collapsed during the evaluation period, and no correction loss or complications, such as infection or nerve damage, were observed. Our clinical findings suggest that Regenos® is a promising bone graft substitute material for intra-articular calcaneal fractures treated by open reduction.

The Regenos® bone implants used in this study were composed of unidirectional HAp of 99.9% purity and 75% porosity. Regenos® is manufactured using a template consisting of ice columns, which leads to the formation of unidirectional oval pores with major and minor axes of approximately 300 and 100 μm, respectively [3]. The compressive strength of this material in the direction of pores is approximately 13 MPa, which is higher than that of conventional HAp with similar porosity [8]. As new bone is formed within the unidirectional pores, the compressive strength of the material increases, reaching 3.4 times of the initial strength after 12 weeks in animal models [8]. Because blood vessels and bone marrow-like tissue are generated within the implant material, newly formed bone undergoes remodeling and is maintained [9]. Karageorgiou et al [5] reported that pore sizes of 100 to 300 μm are suitable for promoting angiogenesis and osteoconductivity. Iwashashi et al [3] histopathologically investigated the new bone formed inside Regenos® bone implants that had been transplanted into bone defects in rabbit tibia and observed bone formation as early as 2 weeks, with the bone formation rate ranging from 33% to 55% at 6 weeks post-implantation. Due to these properties, Regenos® bone implants were evaluated for their potential to repair large intra-articular calcaneal fractures.
As conventional HAp is highly stable in vivo, bone reconstruction in response to mechanical stimulation does not typically occur in bone defects filled with HAp. Therefore, bone at defect sites repaired with HAp implants is fragile and prone to fracture [5]. However, because Regenos® contains suitable pore sizes and porosity for promoting bone conduction [4], new bone formation can be expected within the material upon implantation. In the present study, the continuity of Regenos® with the bone surrounding fracture sites was first observed in x-ray images approximately 6 weeks after surgery, and consolidation with the surrounding bone was confirmed 3 months after surgery in CT images. Watanabe et al [10] also reported that good bone formation occurred in bone defects created in the lower portion of a dog hind limb following transplantation of Regenos® cubes that were fixed in combination with a metal plate. Although the interconnected porous structure of Regenos® imparts a compressive strength comparable to that of cancellous bone, this bone graft substitute does not permit immediate loading after reparative surgery. However, our present findings demonstrate that this synthetic bone substitute has sufficient initial strength for repairing defects in the loaded portion of bone, if the load is minimized for the first few weeks post operatively.

Although plate fixation is often used to treat calcaneal fractures, this approach has several disadvantages, including an increased potential for skin necrosis, infection, and sural nerve damage, inflammation of the peroneal tendons, and necessity for a recovery period with no weightbearing [3]. In the treatment procedure used here, four calcaneal fractures were reduced and filled with Regenos® bone substitute. Using this approach, the opened area was smaller than that needed for plate fixation procedures, thereby decreasing the risk of post-surgery complications, such as skin necrosis. Notably, filling the bone defects with a bone substitute supported the reduction position, which was maintained by KW and SP. The use of Regenos® was also advantageous because the pins could be removed less invasively compared to plate and screw fixation. Several factors may explain why the present treatment outcomes were similar to those typically observed for bone defects repaired by plate fixation. In particular, long-term stabilization of the defect site was achieved due to autologous bone formation within the Regenos® implants. In addition, the unidirectional porous structure of Regenos® provides support in the load direction, and Regenos® granules were also used in combination with the cube to fill the defect site, which would provide further mechanical support.

The approach described here for filling large bone defects is expected to provide performance equivalent to plate fixation with respect to the acquisition and retention of an anatomically reduced position, and is considered to be safer due to a reduced risk of complications. Further, filling bone defects after open reduction helps prevent correction loss. Combining bone grafting with pin fixation was useful for suppressing posterior talocalcaneal articular surface dislocation and Bohler’s angle decline by avoiding postsurgical correction loss. In addition, this treatment strategy permitted post-surgical weight bearing and ankle joint motion training to be started within 4 to 6 weeks, which may help prevent joint contracture and bone atrophy.

Based on the amount of Regenos® material required in each of the present surgeries, relatively large bone defects were formed after the reduction operation. The two fractures classified as Type3AB in the Sanders classification tended to require more Regenos® material to fill the bone defect (Table 1). These findings suggest that fracture severity and bone defect size after reduction operation are correlated.

In the early postoperative period following bone defect repair, during which compressive strength and bone formation increases, the use of Regenos® as a bone graft substitute is expected to overcome the limitations of commonly used bone graft substitutes. For example, in the case of ß-TCP, the compressive strength of the implanted bone is lower than that of the material alone until 3 to 24 weeks after transplantation [11]. In addition, decreased volume and damage to bone graft substitutes have been reported for HAp and CPC after long-term use [6]. Our present findings indicate that Regenos® is an excellent bone graft substitute in calcaneus fracture surgery.

Conclusions

Regenos® cubes and granules were used to repair bone defects formed after open reduction without plates for the treatment of intra-articular calcaneal fracture. The patients’ postoperative recoveries were excellent, and fusion of the Regenos® with the surrounding bone and reconstruction of trabecular bone were confirmed. Our present clinical findings indicate that Regenos® is a useful bone graft substitute material for filling large bone defects formed after intra-articular calcaneal fracture and for the positioning of fractures during open reduction.

References

  1. Chen L, Zhang G, Hong J et-al. Comparison of percutaneous screw fixation and calcium sulfate cement grafting versus open treatment of displaced intra-articular calcaneal fractures. Foot Ankle Int. 2011;32 (10): 979-85. – Pubmed
  2. Essex-Lopresti P. The mechanism, reduction technique, and results in fractures of the os calcis. Br J Surg. 1952;39 (157): 395-419. – Pubmed
  3. Iwasashi M, Sakane Y, Setsugu Y et-al. Bone regeneration at cortical bone defect with unidirectional porous hydroxyapatite in vivo. Key Eng Mat. 2009: 396-398:11-14. – link
  4. Iwasashi M, Sakane M, Shirai Y et-al. The increase of the mechanical strength of novel unidirectional porous hydroxyapatite ceramics in vivo. J Bone Miner Res. 2007: 22:S262. – link
  5. Karageorgiou V, Kaplan D. Porosity of 3D biomaterial scaffolds and osteogenesis. Biomaterials. 2005;26 (27): 5474-91. – Pubmed
  6. Ohta H, Sato K, Morikawa K et-al. Calcium phosphate cement for curreted benign bone tumors. The Central Japan Journal of Orthopaedic Surgery & Traumatology (Japanese). 1998: 41:1269-1270. – link
  7. Omoto H, Nakamura K. Method for manual reduction of displaced intra-articular fracture of the calcaneus: technique, indications and limitations. Foot Ankle Int. 2001;22 (11): 874-9. – Pubmed
  8. Sanders R. Intra-articular fractures of the calcaneus: present state of the art. J Orthop Trauma. 1992;6 (2): 252-65. – Pubmed
  9. Suetsugu Y, Hotta Y, Iwasashi M et-al. Structural and tissue reaction properties of novel hydroxyapatite ceramics with unidirectional pores. Key Eng Mat. 2007: 330-332:1003-6. – link
  10. Watanabe A, Sakane M, Funayama T et-al. Novel unidirectional porous hydroxyapatite used as a bone substitute for tibial wedge osteotomy in canines. Biomaterials Research. 2009:14(1): 6-9 – link
  11. Yamasaki N, Hirao M, Nanno K et-al. A comparative assessment of synthetic ceramic bone substitutes with different composition and microstructure in rabbit femoral condyle model. J. Biomed. Mater. Res. Part B Appl. Biomater. 2009;91 (2): 788-98. – Pubmed

The Use of Platelet-Rich Plasma with Autologous Bone Graft in Arthrodesis: A Salvage Procedure to correct the failure of a Keller Arthroplasty

by Antonio Córdoba-Fernández, PhD1, Jesús Álvarez-Jiménez, PhD2pdflrg

The Foot and Ankle Online Journal 6 (2): 2

Sometimes the success of orthopedic and podiatric surgery may be compromised by inadequate bone repair. In recent years, new tools have been used to improve bone healing by accelerating the rate of bone formation and maturation of the matrix. For instance, there is currently great interest in the use of platelet gel to repair bone defects and accelerate the bone healing process. We report the case of a patient with recurrent hallux valgus following Keller resection arthroplasty for whom the problem was resolved with the use of an autologous cancellous bone graft enriched with platelet-rich plasma as a salvage procedure to enhance arthrodesis. The use of bone graft enriched with platelet-rich plasma (PRP) is a technology in the field of foot surgery should be investigated further.

Key words: Bone graft, Platelet- rich plasma, Keller arthroplasty, Salvage surgery

Accepted: January, 2013
Published: February, 2013

ISSN 1941-6806
doi: 10.3827/faoj.2013.0602.002


Address correspondence to: Antonio Córdoba-Fernández, Departamento de Podología, Universidad de Sevilla, Edificio Docente de Fisioterapia y Podología, Calle Avicena s/n 41009- Sevilla, Spain.

1Titular Professor. Departamento de Podología, Sevilla, Universidad de Sevilla, Edificio Docente de Fisioterapia y Podología, Calle Avicena s/n 41009- Sevilla, Spain. (034) 954486539 acordoba@us.es
2Assistant Professor. Departamento de Podología, Sevilla, Universidad de Sevilla, Edificio Docente de Fisioterapia y Podología, Calle Avicena s/n 41009- Sevilla, Spain. (034) 954486539 jalvarez@us.es


The Keller-Brandes excision arthroplasty technique has been used for decades for the treatment of symptomatic hallux valgus and hallux rigidus. It is even today still sometimes considered a valid procedure for the management of painful adult hallux valgus associated with arthritis of the metatarsophalangeal joint.[1,2] However, the technique often causes the patient dissatisfaction because it fails to maintain the proper alignment and biomechanical functionality of the hallux.

The most common complications associated with the procedure that have been reported in the literature include recurrence of the deformity, transfer metatarsalgia, excessive shortening of the toe, and “cock up” deformity.[3-6] In most cases, the recurrence of the deformity is the result of poor correction of the inter-metatarsal angle after the procedure. Although the technique is out-dated today, it is still relatively common to find patients who have complications after undergoing a Keller arthroplasty. Salvage of the failed procedure by metatarsophalangeal joint arthrodesis (MTPJ-A) of the hallux is a complex surgical problem, especially if it results in shortening of the hallux.

The use of bone graft enriched with platelet-rich plasma (PRP) is a relatively novel technology in the field of podiatric and orthopedic surgery. It is used to enhance bone formation and reduce the risk of delayed consolidation or non-union. The positive impact of PRP on bone healing is attributed to the angiogenic, proliferative, and differentiating effect on osteoblasts of the growth factors and tissue adhesion molecules it contains.[7] The results of numerous studies that have used PRP associated with autologous or heterologous bone grafts show promise for achieving the regeneration of long bones and for the treatment of bone defects. Investigators have shown that PRP and its growth factors and cytokines enhance mesenchymal stem cell proliferation.[8,9]

Case Report

A 61 year-old woman presented with painful hallux valgus of the left foot. According to her surgical history, in 1989 she had had an operation to correct hallux valgus of both feet by the Keller technique. In 1996, she had a revision on the left foot by means of re-excision arthroplasty and soft tissue reconstruction due of recurrence of the deformity. Our radiographic examination showed severe joint destruction in both feet with the result of asymptomatic hallux rigidus of the right foot, and hallux valgus of the left foot without significant shortening of the great toe. In both feet, there was broadening and flattening of the second and third metatarsal heads secondary to Freiberg’s disease. (Fig. 1)

Surgery was planned for the left foot, consisting in MTPJ-A of the hallux. The procedure consisted of excision of the base of the proximal phalanx of the second toe, and metatarsal remodeling of the second metatarsal head with stabilization of the joint by means of a Kirschner wire. A cancellous bone graft was extracted from the base of the phalanx, second metatarsal head and first metatarsal head (bunion). This was triturated and mixed with 5 ml of PRP which was subsequently activated with 10% calcium chloride in accordance with the PRGF System® protocol (Biotechnology Institute, Vitoria, Spain).[10] (Fig. 2)

FKellerFig1

Figure 1 Preoperative radiograph shows destruction of the first metatarsophalangeal joint in both feet. Recurrence of hallux valgus with hallux shortening of the left hallux can be observed.

Figure 2

Figure 2 Autologous bone graft triturated and mixed with activated PRP.

A flat osteotomy was performed on the first metatarsal head, and decortication and revascularization at the base of the hallux’s proximal phalanx, with interposition of the graft that had been obtained, and stabilization by means of a 1.5 mm Kirschner wire (Fig. 3). Following surgery, the foot was immobilized in a short leg cast and the patient allowed walk aided by crutches. Progress postoperatively was normal until the fourth week with the onset of inflammation affecting the hallux accompanied by pain and increased local temperature compatible with an infectious process.

Figure 3

Figure 3 Immediate postoperative radiograph of the left foot show interposition of the bone graft with stabilization by Kirschner wire.

This forced the premature withdrawal of the Kirchner wire, and the initiation of antibiotic therapy for three weeks until remission of the clinical signs of infection. The foot remained immobilized in a short leg cast for 4 weeks.

After removal of the cast, the patient was placed in a reverse camber shoe for 4 weeks that elevates and protects the forefoot and allowed full weight bearing assisted by a crutch. Follow-up examinations with radiological control were conducted at 4, 8, 12, and 24 weeks, and one year postoperatively. The 12-week radiological examination showed the presence of lytic lesions at the level of the interphalangeal joint consistent with sequelae of osteoarthritic sepsis. (Fig. 4)

Figure 4 (2)

Figure 4 Twelve week anterior posterior radiograph demonstrating the resorption of graft with partial consolidation. Lytic lesions at the level of the interphalangeal joint by septic osteoarthritis can be observed.

Despite the early removal of the fixation, no delay was observed in consolidation of the bone in the zone of the graft. Instead there was steady progression to full fusion. (Fig. 5)

Discussion

Numerous salvage techniques have been described to resolve complications associated with the Keller-Brandes arthroplasty. These include arthrodesis, re-excision and reconstruction of soft tissue, and placement of hemi-implants or total implants.[6,11] The existing evidence shows that MTPJ-A of the hallux is a good option for the restoration of the biomechanical integrity of the first ray after a Keller arthroplasty.[12]

Figure 5 (2)

Figure 5 One year postoperatively radiograph. Complete fusion and satisfactory alignment of the hallux has been attained.

A prospective study with long-term monitoring carried out sequentially on 28 feet which underwent an MTPJ-A following a failed Keller-Brandes arthroplasty found the procedure to be safe and effective, and to result in functional improvement with high patient satisfaction [13].

However, the technique is sometimes difficult to perform as a result of the resection arthroplasty drastically altering the anatomical configuration of the joint, producing a significant shortening of the hallux with the risk of non-union. In many cases, this circumstance requires the use of an autologous bicortical iliac crest graft combined with rigid fixation elements (low profile plates with cortical screws), thus increasing the technical difficulty of the procedure and its associated risk, as well as donor site morbidity.[12-16]

Although there are no conclusive data on the non-fusion rate following MTPJ-A as a salvage procedure after a failed Keller, according to the literature data, even with stable fixation systems the risk of non-fusion in patients who have undergone a hallux MTPJ-A with interposition of a bone graft as a salvage procedure is in the range 10%–24% compared to only 5%–8% in patients who have undergone the technique as the primary procedure.[15-17] Some of these studies advise against re-fusion after a failed hallux MTPJ-A except for removal of the osteosynthesis material.[18]

New therapies have been used to increase the effectiveness of autologous grafts in bone regeneration for the treatment of bone defects, delayed consolidation, and non-fusion. Some studies have reported satisfactory results associated with the use of PRP for the treatment of bone defects. In the realm of orthopedic surgery, PRP has been used to improve osseous healing in fusion, fracture repair, and limb-lengthening procedures, and to accelerate soft-tissue healing in acute and chronic tendinous injuries.[19-21] Similarly, good results have been reported with the use of PRP to treat recalcitrant nonunions of the lower limbs and in the treatment of post-traumatic spinal fusions.[22-24] PRP has also been successfully employed in association with bone substitutes that have osteoconductive and osteoinductive properties to accelerate the healing process after tibial osteotomy in both animals and humans.[25,26] Although recent studies seem to demonstrate the superiority of other preparations such as recombinant bone morphogenetic protein (rhBMP) associated with bone graft,[27] the recombinant production technique usually involves higher costs than the systems for obtaining autologous PRP.

In the present case, the association of PRP with autologous bone graft led to complete fusion in a bone of poor quality and without rigid fixation elements. Despite the early withdrawal of the Kirschner wire due to the appearance of infection in the interphalangeal joint of the hallux, there was no delay in consolidation, and complete radiological fusion was observed at 24 weeks.

Although the use of a graft obtained from the patient’s own foot has already been reported in the literature as a salvage procedure following a failed Keller,[28] to the best of our knowledge, the present case is the first to use an autologous graft taken from the foot in association with a platelet gel as the salvage procedure.

According to the literature, the use in the technique of non-rigid osteosynthesis material such as Kirschner wires or Steinmann pins in association with the ankle brace surgical shoe is effective, even with immediate loading, and as in the present case, has the advantage of its easy removal in case of complication.[12,29] Nonetheless, it has to be borne in mind that the use of intramedullary fixation elements can lead to increased risk of infection, ankylosis of the hallux’s interphalangeal joint or breakage of the osteosynthesis material in patients who do not adequately comply with postoperative recommendations.

Conclusion

We consider that MTPJ-A with interposition of PRP-enriched autologous bone graft may be a useful alternative for the salvage of failures following Keller arthroplasty when there is no excessive shortening of the hallux. In particular, it can avoid the risks associated with the use of autologous bicortical bone graft and complex osteosynthesis material, with a concomitant reduction in donor site morbidity, better cosmetic results, and reduction in the costs associated with the use of complex osteosynthesis material. We consider that use of bone graft enriched with platelet-rich plasma (PRP) is a relatively novel technology in the field of foot surgery should be investigated further.

References

1. Putti AB, Pande S, Adam RF, Abboud RJ. Keller’s arthroplasty in adults with hallux valgus and hallux rigidus. Foot Ankle Surg 2012 18: 34-38. [PubMed]
2. Schneider W, Kadnar G, Kranzl A, Knahr K. Long-Term Results Following Keller Resection Arthroplasty for Hallux Rigidus. Foot Ankle Int 2011 32: 933-939. [PubMed]
3. Leonhardt K. Results of Keller-Brandes method of hallux valgus surgery. Beitr Orthop Traumatol.1990 37: 510-517. [PubMed]
4. Schneider W, Knahr K. Keller procedure and chevron osteotomy in hallux valgus: five-year results of different surgical philosophies in comparable collectives. Foot Ankle Int 2002 23: 321-329. [PubMed]
5. Axt M, Wildner M, Reichelt A. Late results of the Keller–Brandes operation for hallux valgus. Arch Orthop Trauma Surg 1993 112: 226-229. [PubMed]
6. Machacek F, Easley M, Gruber F, Ritschl P, Trnka HJ. Salvage of a failed Keller resection arthroplasty. JBJS 2004 86: 1131-1138. [PubMed]
7. Marx RE, Carlson ER, Schimmele SR. Platelet rich plasma: growth factor enhancement for bone grafts. Oral Surg Oral Med Oral Pathol Oral Radio Endod 1998 85: 638-646. [PubMed]
8. Vogel JP, Szalay K, Geiger F, Kramer M, Richter W, Kasten P. Platelet-rich plasma improves expansion of human mesenchymal stem cells and retains differentiation capacity and in vivo bone formation in calcium phosphate. Platelets 2006 17: 462- 469. [PubMed]
9. Kocaoemer A, Kern S, Klueter H, Bieback K. Human AB-serum as well as thrombin activated platelet-rich-plasma are suitable alternatives to fetal calf serum for the expansion of mesenchymal stem cells. Stem Cells 2007 25: 1270-1278. [PubMed]
10. Anitua E. The use of plasma-rich growth factors (PRGF) in oral surgery. Pract Proced Aesthet Dent 2001 13: 487-493. [PubMed]
11. Simpson-White R, Joseph G, Khan M. Prosthetic replacement arthroplasty as a salvage operation for failed procedures of the first metatarsophalangeal joint: A small series and literature review. The Foot 2007 17: 174-177. [Website]
12. Coughlin MJ, Mann RA. Arthrodesis of the first metatarsophalangeal joint as salvage for the failed Keller procedure. JBJS 1987 69: 68-75. [PubMed]
13. Georgousis H, Patsalis T, Bertram R. Salvage of the failed Keller-Brandes operation by metatarsophalangeal fusion. Foot Ankle Surg 1996 2: 3-11. [Website]
14. Vienne P, Sukthankar A, Favre P, Werner CML, Baumer A, Zingg PO.  Metatarsophalangeal joint arthrodesis after failed Keller-Brandes procedure. Foot  Ankle Int.  2006 27:824-901. [PubMed]
15. Myerson MS, Schon LC, McGuigan FX, Oznur A. Result of arthrodesis of the hallux metatarsophalangeal joint using bone graft for restoration of length. Foot Ankle Int  2000 21: 297-306. [PubMed]
16. Bennet GL, Kay DB, Sabatta J. First metatarsophalangeal joint arthrodesis: an evaluation of hardware failure. Foot Ankle Int  2005 26: 593-596. [PubMed]
17. Roukis TS. Nonunion after arthrodesis of the first metatarsal-phalangeal joint: a systematic review. J Foot Ankle Surg  2011 50: 710-713. [PubMed]
18. Hope M, Savva N, Whitehouse S, Elliot R, Saxby TS. Is it necessary to re-fuse a non-union of a hallux metatarsophalangeal joint arthrodesis? Foot Ankle Int 2010 31: 662-669. [PubMed]
19. Dallari D, Savarino L, Stagni C, Cenni E, Cenacchi A, Fornasari PM, Albisinni U, Rimondi E, Baldini N, Giunti A. Enhanced tibial osteotomy healing with use of bone grafts supplemented with platelet gel or platelet gel and bone marrow stromal cells. JBJS  2007 A89: 2413-2420. [PubMed]
20. Foster TE, Puskas BL, Mandelbaum BR, Gerhardt MB, Rodeo SA. Platelet-rich plasma: from basic science to clinical applications. Am J Sports Med 2009 37: 2259-2272. [PubMed]
21. Kitoh H, Kitakoji T, Tsuchiya H, Katoh M, Ishiguro N. Transplantation of culture expanded bone marrow cells and platelet rich plasma in distraction osteogenesis of the long bones. Bone 2007 40: 522-528. [PubMed]
22. Chiang CC, Su CY, Huang CK, Chen WM, Chen TH, Tzeng YH. Early experience and results of bone graft enriched with autologous platelet gel for recalcitrant. J Trauma 2007 63: 655-661. [PubMed]
23. Hartmann EK, Heintel T , Morrison RH ,Weckbach A. Influence of platelet-rich plasma on the anterior fusion in spinal injuries: a qualitative and quantitative analysis using computer tomography. Arch Orthop Trauma Surg 2010 130: 909-914. [PubMed]
24. Sanchez M, Anitua E, Cugat R, et al. Nonunions treated with autologous preparation rich in growth factors. J Orthop Trauma. 2009 23: 52-59. [PubMed]
25. Dallari D, Savarino L, Stagni C, Cenni E, Cenacchi A, Fornasari PM, Albisinni U, Rimondi E, Baldini N, Giunti A. Enhanced tibial osteotomy healing with use of bone grafts supplemented with platelet gel or platelet gel and bone marrow stromal cells. JBJS 2007 A89: 2413-2420. [PubMed]
26. Kanthan SR, Kavitha G, Addi S, Choon DS, Kamarul T. Platelet-rich plasma (PRP) enhances bone healing in non-united critical-sized defects: a preliminary study involving rabbit models. Injury 2011 42: 782-789. [PubMed]
27. Calori GM, Tagliabue L, Gala L, D’Imporzano M, Peretti G, Albisetti W. Application of rhBMP-7 and platelet-rich plasma in the treatment of long bone nonunions: a prospective randomized clinical study on 120 patients. Injury 2008 39: 1391-1402. [PubMed]
28. Patel S, Mistry RS, Dodd LE, Shaikh N, Palmer SH. Second toe proximal phalanx interposition bone graft to correct a failed Keller’s arthroplasty. A new technique. Foot Ankle Surg 2009 15: 149-151. [PubMed]
29. Mah CD, Banks AS. Immediate weight bearing following first metatarsophalangeal joint fusion with Kirschner wire fixation. J Foot Ankle Surg 2009 48: 3-8. [PubMed]

Chondroblastoma of the Talus: A case report

by Prasad Soraganvi1emailsm, Ramakanth R2emailsm, Vijay Kumar M3emailsmpdflrg

The Foot and Ankle Online Journal 6 (1): 1

Chondroblastoma is a benign tumor of immature cartilage cells which primarily occurs in the epiphysis of long bones in the second decade of life with slight male preponderance. The diagnosis is obtained from the microscopic picture, showing large collections of chondroblasts surrounded by a matrix of immature fibrous tissue and a few scattered giant cells. Benign chondroblastoma is rarely seen in the bones of the feet. Very few cases of benign chondroblastoma involving the talus have been reported. We report an unusual case of benign chondroblastoma of the talus in a 19 year-old female. Clinical presentation, histological diagnosis and treatment by curettage and bone grafting are described. Also importance of intact cortex and approaching the tumor by making a window in the more involved thin cortex is highlighted. The patient is now asymptomatic and there is no evidence of recurrence at 3 years follow-up.

Key words: Chondroblastoma, bone graft, curettage

Accepted: December, 2012
Published: January, 2013

ISSN 1941-6806
doi: 10.3827/faoj.2013.0601.001


Address correspondence to: Department of orthopaedics, PES Institute of Medical Science and Research, Kuppam, Chittor District– 517425, Andra Pradesh, India

1Assiatant professor, PES institute of medical science and research, Kuppam,AP, India.
2Senior resident, PES institute of medical science and research, Kuppam,AP, India.
3Jr.Consultant, MMHRC,Madurai,India.


Chondroblastoma is a benign tumor of immature cartilage cells.[1] In 1931, Codman classified it as a chondromatous variant of giant cell tumor when he described these lesions in the proximal humerus.[2] A decade later, Jaffe and Lichtenstein renamed it as chondroblastoma and clearly separated it from giant cell tumor.[3] Tumor seems to arise from secondary centers of ossification and the cell of origin arises from the epiphyseal plate or some remnant of it. The lesion is rare, accounting for approximately one percent of all benign bone tumors.[4,5] Treatment has been highly variable but currently usually consists of curettage and packing with bone graft.[2,6]

Its occurrence in small bones is rare. About 12% of all chondroblastoma occur in the bones of the foot. Chondroblastoma in the foot most commonly occurs in subchondral areas of the talus and calcaneal apophysis.[7] In chondroblastoma of the foot and ankle, recurrence is common, and outcomes are generally worse than in other locations in the skeleton.[7] Very few cases of benign chondroblastoma involving the talus have been reported. We report a case of benign chondroblastoma of talus in a 19 year-old female. Clinical presentation, histological diagnosis and treatment by curettage and bone grafting are described along with review of literature.

ChondtalFig1a ChondtalFig1b

Figure 1A and Figure 1B Radiograph of talus showing the lesion involving most of body and the medial cortex is thin compared to lateral cortex in lateral view. (A) Anterior posterior view. (B)

The lesion was approached with a posteromedial incision and by making a cortical window in the medial cortex. The decision was made based on involvement of cortex by the tumor. This has not been described before in the literature. The patient is now asymptomatic and there is no evidence of recurrence at 3 years follow-up.

Case Report

A 19 year-old girl presented with history of pain and swelling in the right ankle since one year. The swelling was insidious in onset and slow in progression associated with mild dull aching pain. Pain increased on walking, and was relieved by rest and analgesics. The patient had no history of trauma or fever. Clinical evaluation revealed that swelling was on the medial aspect of the right ankle and the skin over the swelling was normal. Tenderness was present on deep palpation and there was no local rise of temperature. The swelling was firm-to-hard in consistency and arising from the talus. Range of movement of the ankle and subtalar joint were restricted and painful. There were no distal neurovascular deficits. No appreciable lymphadenopathy was noted. Conventional radiographs showed well-defined, expansile and lucent area within talus involving the body and posterior subchondral area.

?????????? ??????????

Figure 2A and Figure 2A Terminal restriction of movements post operatively. Both Plantarflexed (A) and dorsiflexed. (B)

The lesion was approximately 3.5cms in size. There was no breach in the cortex. Most of the talus was involved except the lateral cortex head. The medial cortex was thinner than the lateral cortex. Stippled calcification with thin trabeculae was seen within the radiolucent area (Fig. 1). Based on clinical and radiological findings, a diagnosis of benign cystic lesion of the right talus was made and aneurismal bone cyst, chondroblastoma were considered for differential diagnosis.

An open biopsy, curettage and bone grafting was performed. The lesion was approached by a posteromedial incision. The decision of approaching the lesion by a posteromedial incision was made based on the extent of involvement of the cortex. A window was made in the medial cortex of talus. Extensive intralesional curettage was performed. The defect was then filled in by bone graft harvested from the iliac crest and bone substitutes. Microscopic examination of the tissue revealed sheets of cells with oval to elongated nuclei. Scattered osteoclastic giant cells were present. Isolated island of cartilaginous matrix with focal area of linear calcification (chicken wire calcification) were seen and a diagnosis of chondroblastoma was made. Post operatively below knee cast was applied for two months. The patient was started on partial weight bearing walking after 2 months and full weight bearing walking after 3 months.

At the 6 month follow post-operatively the patient was ambulating normally without pain or limp. Range of motion of the ankle and subtalar joint were improved, but terminal 10 to 20 degree range of movement was restricted. (Fig. 2A and 2B)

ChondtalFig3

Figure 3 Two year Post operative radiograph showing satisfactory incorporation of bone graft.

At 2 year follow up radiograph showed good incorporation of bone graft and there was no sign of recurrence. (Fig. 3)

Discussion

Chondroblastoma is benign cartilaginous tumor which has typical clinical pathological features. It accounts for one percent of all benign tumors.[8,9,10,11,12] Chondroblastoma has been seen in people of all age groups. Adults in their second decade of life appear to have a higher prevalence of the tumor. A study of 104 cases by Bloem and Mulder revealed an average age of 16 years in tumors affecting long bones and 28 years in short, tubular bones, most notably the talus and calcaneum.[13] Males are affected more than females by approximately 2:1 rate. The tumor is characteristically centred in the epiphysis of long bones.[14] Chondroblastoma is a benign tumor but occasionally the tumor may show a more aggressive pattern, with invasion of the joint spaces, adjacent bones, and very rarely, the metastases.

Typically on a radiograph a chondroblastoma presents with an eccentrically or centrally located osteolytic lesion that involves the epiphysis or other secondary ossification centers.[15] In 20% to 25% of the cases metaphyseal involvement is also seen.[5]

Cortical expansion, with erosion and periosteal reaction may be present occasionally.[15] There may be stippled calcification or there may be no matrix mineralization. The tumor is adjacent to an articular surface or an apophysis. Extension of the tumor to the articular surface had been observed.[7]

Computerized tomography (CT) scans can provide valuable information in helping diagnose and evaluate the extent of a chondroblastoma. The size of the lesion can be better appreciated with CT scans as compared to plain radiographs. CT scan is useful for defining the relationship of the tumor to the joint, the integrity of the underlying bone, and to identify intralesional calcifications. Also, the amount of calcification can be better evaluated.[16]

Magnetic resonance imaging (MRI) can help in the diagnosis and in the differentiation of a chondroblastoma. MRI is especially useful when plain radiographic findings are inconclusive. MRI scans show the very high signal intensity on T2 weighted scans. Bone scan shows avid tracer uptake in the lesion.[7] In MRI scan surrounding bone marrow and soft tissue edema and periosteal reactions may be seen.[16] Nuclear scans have shown that chondroblastoma are more hyperemic than the surrounding bone but are nonspecific for actually diagnosing a chondroblastoma.[16]

The tumor is composed of cellular and matrix rich areas. Tumor cells are round or polygonal cells with an oval or round nucleus and eosinophilic cytoplasm make up the cellular areas. The nuclei are often indented and lobulated. In non-decalcified sections the chondroblasts appear focally delimited by a thin calcification rim, so called chicken wire.[17] Mitosis is always typical and is quite frequent in the cellular areas. Matrix rich areas are composed of different types of matrix like chondroid, osteoid, fibrous and rarely mature hyaline cartilage.[15]

Of all the bone tumors, chondroblastoma represents less than 1% with only 20% of it occurring in the foot. Chondroblastoma of foot is most commonly found in the talus and calcaneum.[10,11,18,16,19] Approximately 4% of all chondroblastoma arise in the talus.[5,14,20] Very few cases of chondroblastoma involving the talus have been reported.

ChondtalTab1

Table 1 Chondroblastoma of the talus, a review of cases.

The clinical data of 12 reported cases and our case are summarized in Table 1. The average age at presentation was 19 years. Three patients presented in the first decade, five patients were between 10 and 20 years and 5 patients were above 20 years. Males are affected more than females by approximately 2:1 rate which is comparable with other large series reported by Ramappa, et al.,.[5]

In a review of 322 cases of chondroblastoma by Fink only 42 involved the foot and the posterior subchondral area of talus is more common site.[7] Invasion of the sinus tarsi and simultaneous calcaneal involvement has also been reported.[9,16]

Out of 13 cases reviewed here, the talar body was involved in 11 patients and the talar neck was involved in two patients (table 1). In the majority of the patients the left side of the talus was involved. Patients often present with pain and swelling around the joint.[5] Chondroblastoma is known to present with atypical features when the foot is involved. Involvement of the talus can present with pain in the ankle joint more commonly. Approximately 20-50% of the patients give a history of trauma.[9] All of the patients reported with chondroblastoma of talus presented with pain and most of them had swelling (table 1). Most of the patients had pain for several months before presentation. The case reported here had pain in ankle one year before presentation.

Localized swelling and a decreased range of motion are common clinical findings, with the majority of patients having tenderness on direct palpation. Rarely pathological fracture is the presenting feature in about 1-13% of patients.[9] Since chondroblastoma is not common in the talus, patients presented early with complaint of pain are misdiagnosed.[21,16] Two patients presented within one month after pain in ankle had normal radiograph initially (table 1). Both of these patients were misdiagnosed at early presentation. Chondroblastoma was diagnosed when a radiograph taken after few years showed the lesion. One case presented at one year with pain in the ankle, radiograph showed no significant changes, but MRI revealed the lesion in talus.[22] Because of this atypical presentation chondroblastoma of the talus may be confused with synovitis, tendinitis or other lytic lesions of bone like aneurismal bone cyst, tuberculosis.

The diagnosis of these lesions, in uncommon sites, is often delayed for months or even years, and are often treated as ankle sprains. Metastasis of benign chondroblastoma is a rare event. Benign pulmonary metastases have been reported with primary tumor involving the talus and the author concluded that all patients need to be evaluated regularly from the onset for possible lung metastasis so that deposits can be detected early for total resection.[18]

Treatment of the primary lesion consists of complete curettage and bone grafting.[15] Recurrences following this treatment are to occur in 10-45%.[9] Extending the zone of the curettage by removing two or three additional millimetres of bone using a mechanical bur, or by using phenol or liquid nitrogen placed in the tumor cavity have been proposed as in a method to reduce the risk of local recurrence.[7] Involvement of articular cartilage treated with osteochondral autograft transfer from the lateral femoral condyle has been reported with good results.[23] Excision of the talus with calcaneotibial arthrodesis has been reported by Jambhekar, et al.,.[18] Out of thirteen cases, eight cases were treated with curettage and bone grafting, two cases only with curettage, two cases with resection and one case with excision of talus. (Table 1)

Curettage and bone grafting has shown good out come when articular surface is not involved. Total talectomy may be contemplated in cases where there is extensive involvement of the talus. The recurrence rate of chondroblastoma is reported to be 10 % to 15 %.[15] Open growth plates have also been considered as a risk factor for recurrence.[4] Springfield., et al. in their review of 70 cases of chondroblastoma, have suggested that recurrence is secondary to less aggressive surgical curettage due to fear of injury of the physis.[20] While in a review of 73 cases of chondroblastoma by Ramapa., et al. treated between 1977 and 1998 , it is concluded that one possible explanation of recurrence of chondroblastoma in their case might be the anatomic location. Also lower recurrence rate is found in patients treated by packing the defect with polymethylmethacrylate instead of bone graft.[5]

Bloem, et al., in their study of 104 chondroblastoma cases have follow up exceeding 3 years, but they failed to see any recurrences after this period.[13] In chondroblastoma of the foot and ankle, recurrence is common, and outcomes are generally worse than in other locations in the skeleton.[7] Recurrent lesions should be treated with repeat curettage. Recurrence and severe destruction of bone integrity may necessitate ankle arthrodesis or en-bloc resection with associated functional loss. Patients with recurrent lesions should have follow-up CT scans of the chest to detect pulmonary nodules and if present nodules should be excised.[7]

In our case, the lesion was large measuring approximately 3.5cms. Most of talus was involved except the lateral cortex and head. The articular surface and all cortices were intact. Hence, we planned for curettage and packing the cavity with bone graft. The lateral cortex was thick as compared to the medial cortex. Hence, we have decided to approach the tumor by the postero-medial approach. Since the lateral cortex was thick approaching laterally and making a window in the lateral cortex would have weakened it.

The window was made in the medial cortex followed by curettage and bone grafting. Bone was harvested from the iliac crest and mixed with bone substitute to fill the cavity. The patient underwent uneventful recovery and asymptomatic at two year follow up, also follow-up radiograph shows satisfactory incorporation of the bone graft with no signs of recurrence. Most of the reported cases of chondroblastoma of talus have been treated by posterolateral approach or anterolateral approach.[8,21,16,19,24] Medial approach was done in one case where the talus and calcaneum were involved simultaneously.[25] In larger lesions, talectomy was done. Our case had a larger lesion (3.5 cm) with a relatively thicker lateral cortex; hence the posteromedial approach was made with a window in medial cortex. It is desirable to approach the lesion without weakening the intact thick cortex. Posteromedial approach and making a window in the medial cortex have not been described in reports on this condition. Khan and Moore each described a surgical approach using a small anterolateral window in the neck of the talus to gain access to the lesion.[24,26]

Yu and Sellars used a lateral incision with direct curettage near the opening of the sinus tarsi, and gained access to the lesion through this approach.[16] Wu concluded that eccentrically based talar chondroblastoma should be treated with talectomy.[27] Sterling described approaching the lesion without entering the cavity of the adjacent joint via the sinus tarsi.[9] Small-sized tumors can effectively be curetted through arthroscopic portals with minimal morbidity.[22] Anderson reported small chondroblastoma of the talus involving articular surface treated with osteochondral autograft transfer.[23] For best surgical results with minimal morbidity, there should be early diagnosis and proper choice of the best surgical procedure. The case reported here utilizes a comprehensive approach which decided on the extent of the lesion involving the talus. We believe that the surgical approach should be decided on the location of the lesion, articular cartilage involvement and also on involvement of the medial or lateral cortex for maximum restoration of function.

Conclusion

Chondroblastoma of the talus is a rare condition and it should be considered in the differential diagnosis in lytic lesion of the talus. A thorough history, physical examination and proper radiographic studies is mandatory. Diagnosis is confirmed by imaging study supplemented with open biopsy. The surgical technique and exposure of the tumor are modified to suit the requirements in each ease. Properly performed extensive curettage and bone grafting is a good option for complete removal of tumor.

References

1. Rosai J. Ackerman’s Surgical Pathology. 7th Edition, St Louis, CV Mosby, Chapter 24, 1989; Vol 2.
2. Codman EA. The classic:  Epiphyseal chondromatous giant cell tumors of the upper end of the humerus. Surg Gynecol Obstet.1931;52:543-48. Clin Orthop Relat Res 2006 450: 12-6. [PubMed]
3. Jaffe HL, Lichtenstein LL. Benign Chondroblastoma of bone: A reinterpretation of the so-called calcifying or chondromatous giant cell tumor. Am J Pathol 1942 18: 969-691. [PubMed]
4. Campanacci M. Bone and Soft Tissue Tumors: Clinical Features, Imaging, Pathology and Treatment. 2nd edition. New York, Springer; 1999. [Website]
5.  Ramappa AJ, Lee FY, Tang P, Carlson JR, Gebhardt MC, Mankin HJ: Chondroblastoma of bone. JBJS 2000, 82A: 1140-1145. [PubMed]
6. Simon MA Springfield, D. S: Surgery for Bone and Soft Tissue Tumors. Philidelphia, Lippincott-Raven; 1998: 190-191.
7. Fink BR, Temple HT, Chiricosta FM, Mizel MS, Murphey MD:  Chondroblastoma of the foot.  Foot Ankle Int 1997 18: 236-242.[PubMed]
8. Zhang K, Geo Y, Dai H, Zhang S, Li G,  Yu B. Chondroblastoma of the talus: A case report and literature review. Foot Ankle Surg 2012 51: 262-265. [PubMed]
9. Sterling G, Wilson A. Chondroblastoma of the talus: a case report. J Foot Ankle Surg 2002 41: 178-182. [PubMed]
10 Khalifa YE. Chondroblastoma of bone: Management and results of surgical treatment in ten patients. Pan Arab J Orth Trauma 2004 8: 221-229. [Website]
11. Basu N, Roy A, Chatterjee S, Mallik MG, Sengupta S, Basu A, Das A.  Chondroblastoma of talus – A case report. J Indian Assoc Pediatr Surg 2001 6: 58-60. [Website]
12. Dahlin DC, Ivins JC: Benign Chondroblastoma. A study of 125 cases. Cancer 1972 30: 401-413.
[PubMed]
13.Bloem JL, Mulder JD. Chondroblastoma: A clinical and radiological study of 104 cases. Skeletal Radiol 1985 14: 1-9.
[PubMed]
14. Kurt AM, Unni KK, Sim FH, McLeod RA: Chondroblastoma of bone. Hum Pathol 1989 20: 965-976. [PubMed]
15. Sepah YJ, Umer M, Minhas K, Hafeez K : Chondroblastoma of the cuboid with an associated aneurismal bone cyst: a case report. J Med Case Rep. 2007 1:135. [PubMed]
16 Yu GV, Sellers CS. Chondroblastoma of the talus. J Foot Ankle Surg 1996 35: 72-77.  [PubMed]
17.  Monda L, Wick MR.  S-100 protein immunostaining in the differential diagnosis of chondroblastoma.  Hum Pathol 1985 16: 287-293. [PubMed]
18. Jambhekar NA, Desai PB, Chitale DA, Patil P, Arya S. Benign metastasizing chondroblastoma. Cancer 1998 82: 675-678.
[PubMed]  
19.  Sankaran B, Duggal K., Wani GM. Chondroblastoma of talus – A case report. Indian journal of orthopaedics 1979 13 :81-83.
20.  Springfield DS, Capanna R, Gherlizoni F, Picci P, Campanacci M. Chondroblastoma: A review of seventy cases. JBJS 67A: 748-755. [PubMed]
21.  Ochsner PE, von Hochstetter AR, Hilfiker B. Chondroblastoma of the talus: Natural development over 9.5 years. Arch Orthop Trauma Surg 1988 107: 122-125. [PubMed]
22. Marcelo PP, Albert AMM, Daniel TA.  Benign bone tumors subperiosteal on the talar neck resected arthroscopically: case reports. Einstein 2010 8: 354-357.  [Website]
23. Anderson AF, Ramsey JR. Chondroblastoma of the talus treated with osteochondral autograft transfer from the lateral femoral condyle. Foot Ankle Int 2003 24: 283-287. [PubMed]
24  Moore TM, Roe JB, Harvey JP. Chondroblastoma of the talus. A case report. JBJS 1977 59A: 830-831. [PubMed]
25.  Ohno T, Kadoya H, Park P, Yamanashi M, Wakayama K, Ihtsubo K, Tateishi A, Kijima M. Case report 382. Benign chondroblastoma of talus invading calcaneus. Skeletal Radiol 1986 15: 478-483. [PubMed]
26. Khan FA. Benign chondroblastoma of the talus. JR CoIlege Surg Edin 1988 33: 222-224. [PubMed]
27.  Wu, KK Chondroblastoma of the foot. J Foot Surg 1989 28: 72-77. [PubMed]


© The Foot and Ankle Online Journal, 2013

A Rare Case of Aneurysmal Bone Cyst of the Calcaneum

by Prasad Soraganvi, Karan Kukreja, Ramakanth R.

The Foot and Ankle Online Journal 4 (4): 1

Aneurysmal bone cyst (ABC) is a benign solitary lesion of unknown aetiology. ABC’s mainly occur in the long bones but only rarely in the bones of the feet. For example, frequency of occurrence in the foot is only 3% compared to other bones of the body. Very few cases of ABC involving the calcaneum have been reported. We report an unusual case of ABC of calcaneum in a 55 year-old male. Clinical presentation, histological diagnosis and treatment by curettage and bone grafting are described. The patient is now asymptomatic and there is no evidence of recurrence at 2 years follow-up.

Key words: ABC, calcaneum, curettage, bone grafting.

Accepted: March, 2011
Published: April, 2011

ISSN 1941-6806
doi: 10.3827/faoj.2011.0404.0001


The aneurysmal bone cyst (ABC) is an expansile cystic lesion that most often affects individuals during their second decade of life and may occur in any bone in the body. [1-5] Although benign, the ABC can be locally aggressive and can cause extensive weakening of the bony structure and impinge on the surrounding tissues.

Jaffe and Lichtenstein first described ABC in 1942. [6] As defined by the World Health Organization, the ABC is a benign tumor like lesion described as “an expanding osteolytic lesion consisting of blood-filled spaces of variable size separated by connective tissue septa containing trabeculae or osteoid tissue and osteoclast giant cells.” [4]

ABCs both erode and cause ‘expansion’ of underlying cancellous and cortical bone. [7] Around the lesion there is always a shell formed by periosteal new bone and, although this may be only millimeters thick, it prevents direct extension into the soft tissues. [8] The expansile nature of the lesions can cause pain, swelling, deformity, disruption of growth plates, neurologic symptoms (depending on its location), and pathologic fracture. [1-3]

ABC’s in the foot are uncommon. ABC’s present about 1% of all primary bone tumors collectively. [9] Its frequency of occurrence in foot is only about 3% compared to other bones of body. [10] Occurrence within the calcaneum are rare, and generally present as chronic heel pain and swelling, but may rarely present as pathologic fracture. [11]

A plethora of cystic lesions can occur in the calcaneum, which makes definitive diagnosis difficult based on imaging only. The differential diagnosis includes simple bone cyst, ABC (primary or secondary), chondroblastoma, giant cell tumor (GCT), osteosarcoma, ossifying hematoma or pseudotumor of hemophilia. This mandates histopathological diagnosis prior to the definitive management.

We report a rare case of ABC involving calcaneum of 55 year-old male confirmed by histopathology report and we performed curettage and bone grafting of cyst.

Case Report

A 55 year-old male, manual laborer by occupation and known diabetic on treatment presented with a chief complaint of swelling in right heel during the last two years. An increase in swelling was associated with pain in heel from the last one year. He had difficulty in walking because of pain. For the last two months, he was unable to work due to pain. He did give history of blunt trauma prior to the onset of symptoms.

Clinical evaluation revealed swelling over the lateral aspect of the heel and the skin over the swelling was stretched. Tenderness was present on palpation but there was no local rise of temperature. The swelling was bony hard in consistency and arising from calcaneum. There were no distal neurovascular deficits or any significant lymphadenopathy.

Radiographic examination of his ankle revealed an eccentric, expansile, multiloculated lytic lesion of the calcaneum with thin trabeculae traversing the cystic cavity. (Fig. 1) There was no breach in the cortex. Based on clinical and radiological findings, a diagnosis of benign cystic lesion of right calcaneum was made.

Figure 1 Pre-operative radiographs, antero posterior and lateral views showing eccentric expansile lytic lesion with thin shell of cortex and trabaculae traversing the cyst.

Open biopsy of the cyst was made to confirm the diagnosis. The cyst grossly consisted of cavities filled with brown altered blood. Histopathological report revealed large blood filled cavities lined by fibrous septa, with occasional osteoclastic giant cells. (Fig. 2A and 2B)

Figures 2A and 2B Histologic slides reveal large blood filled cavities lined by fibrous septa (A), with occasional osteoclastic giant cells, haemosiderin laden macrophages with a thin rim of bone. (B)

Hence the diagnosis of ABC involving the right calcaneum was made. The patient was scheduled for cyst curettage and bone grafting. By curvilinear incision over the lateral aspect of heel, the calcaneum was exposed. A large cortical window was made and the entire cyst curettage was done. Then the cavity was washed with saline and packed with cortico-cancellous bone graft harvested from both iliac crests in addition to synthetic bone substitute. The patient was advised non-weight bearing walking on the affected limb for eight weeks. Later mobilised with partial weight bearing walking for a further four weeks and then followed by full weight bearing on affected limb.

At six months of follow up, the patient was pain free and had returned to his regular activities. At two years follow-up, the patient is clinically asymptomatic. There is no evidence of recurrence. (Figs. 3A, 3B and 3C)

Figure 3: Follow-up radiographs showing incorporation of graft material at 1 month (A), 6 months (B), and at 2 years follow-up(C) showing consolidation of graft and no recurrence.

Discussion

ABC is an entity on its own having unique clinical, radiological and diagnostic behavior. [7] The true etiology of ABCs is unknown. Most investigators believe that ABCs are the result of a vascular malformation within the bone; however, the ultimate cause of the malformation is a topic of controversy. [12]

The concept of an ABC as a secondary phenomenon occurring in a pre-existing lesion is based on the fact that in approximately one-third of the cases a pre-existing lesion can be identified, the most common of which is giant-cell tumor. [13] ABCs are common around the knee joint of the young [11] and have an equal incidence in both genders. About 50-70% of ABCs occur in the second decade of life, with 70-86% occurring in patients younger than 20 years, which makes this case even more unusual. [10]

On histology, the ABC is characterized by blood filled cavities lined by fibrous septa. The stroma contains proliferative fibroblasts, spindle cells, areas of osteoid formation, and an uneven distribution of multinucleated giant cells. The tissue within the septations includes cavernous channels that do not contain a muscular or elastic layer in their walls. Areas of new and reactive bone formation can also be found in the ABC. Mitotic figures are common to ABCs, but no atypical figures should be evident. [10]

Bone cysts of the calcaneum are rare lesions. These may include a wide spectrum of non-neoplastic cysts, benign or malignant neoplastic lesions ranging from simple bone cyst, ABC (primary or secondary), chondroblastoma, giant cell tumor (GCT), and an osteosarcoma (especially telangiectatic). [11]

Clinically, calcaneal cysts are often symptomatic and present with heel pain, although some of these lesions may remain asymptomatic and are detected as incidental findings. Even though there are many typical radiograph, computed tomographic (CT) scan, and magnetic resonance imaging (MRI) findings to confirm a diagnosis of ABC, an open biopsy must be performed because of the high frequency of accompanying tumors. [11] When a biopsy is performed, the sample should ideally include material from the entire lesion; a limited biopsy could easily cause a coexisting lesion to be missed, leaving the patient with a morbid prognosis.

There are various methods of treatment based on the site and size of the lesion, which include curettage, which may be supplemented with various adjuvant therapies such as bone grafting, use of liquid nitrogen, phenol instillation and Poly (methyl methacrylate) (PMMA) cement.

Other modalities such as wide excision or arterial embolisation may be considered. Although relatively rare, there is no reason to assume that ABCs of the feet will respond to treatment or recur any differently from ABCs that occur elsewhere in the body. Surgical curettage is sufficient to treat most ABCs of the feet, including the calcaneum. [14]

Despite a favorable outcome of ABCs with an overall cure rate of 90-95%, [15] one of the most common problems encountered during management is frequent recurrence. The incidence of recurrence has been noted to vary between 59% in cases treated with intralesional excision [16] and 0% in cases with resection. Recurrence usually happens within the first year after surgery, and almost all episodes occur within 2 years. [17] Therefore, a patient of ABC needs to be observed for at least this period of time to exclude any recurrence. It is beneficial to detect recurrence early when the lesion is still small and easier to treat.

To conclude, ABC of the calcaneum is an extremely uncommon entity. Proper diagnosis entails correlating the clinical presentation, anatomical location, radiological profile, and histopathological appearance. This is imperative not only to exclude other more common histological mimics, but also for choosing the appropriate therapeutic regimen and prognosticating the disease outcome.

In a case of calcaneal cystic lesion, ABC should be considered as one of the differential diagnosis. Hence histological diagnosis is essential. Curettage and bone grafting is a valuable option.

References

1. Clayer M. Injectable form of calcium sulphate as treatment of aneurysmal bone cysts. ANZ J Surg 2008 78(5): 366-370.
2. Segall L, Cohen-Kerem R, Ngan B Y, Forte V. Aneurysmal bone cysts of the head and neck in pediatric patients: A case series. Int J Pediatr Otorhinolaryngol 21 2008: epub ahead of print.
3. Burch S, Hu S, Berven S. Aneurysmal bone cysts of the spine. Neurosurg Clin N Am 2008 19(1): 41-47.
4. Brastianos P, Gokaslan Z, McCarthy E F. Aneurysmal bone cysts of the sacrum: a report of ten cases and review of the literature. Iowa Orthop J 2009 29: 74-78.
5. Sun Z J, Zhao Y F, Yang R L, Zwahlen R A. Aneurysmal Bone Cysts of the Jaws: Analysis of 17 Cases. J Oral Maxillofac Surg Jan 26 2010 (Medline).
6. Jaffe H L, Lichtenstein L. Solitary unicameral bone cyst with emphasis on the roentgen picture, the pathologic appearance and the pathogenesis. Arch Surg 1942 44: 1004-1025.
7. Campanacci M, Capanna R, Picci P. Unicameral and aneurysmal bone cysts. Clin Orthop 1986 204: 25-36.
8. Enneking WF. Aneurysmal bone cyst. In: Musculoskeletal tumor surgery. New York: Churchill Livingstone, 1983; 1513-29.
9. Duke Orthopaedics: Wheeless’ Textbook of Orthopaedics, Aneurysmal Bone Cyst, Online article, Jan 2007.
10. Anand MK, Wang EA. Aneurysmal Bone Cyst. eMedicine, Jan 2007.
11. Unni KK, Inwards YC. Conditions that normally simulate primary neoplasms of the bone. In: Unni K K, Inwards Y C, editors. Dahlin’s Bone Tumors. 6th edition. Philadelphia: Lippincott Williams and Wilkins; 2010. p. 305-80.
12. Cottalorda J, Bourelle S. Modern concepts of primary aneurysmal bone cyst. Arch Orthop Trauma Surg 2007 127(2): 105-114
13. Kransdorf MJ, Sweet DE. Aneurysmal bone cyst: concept, controversy, clinical presentation, and imaging. AJR 1995 164: 573-580.
14. Chowdhry M, Chandrasekar CR, Mohammed R, Grimer RJ. Curettage of aneurysmal bone cysts of the feet. Foot Ankle Int. 2010 31(2): 131-135.
15. Marcove RC, Sheth DS, Takemoto S, Healey JH. The treatment of aneurysmal bone cyst. Clin Orthop Relat Res 1995 311: 157-163.
16. Schreuder HW, Veth RP, Pruszczynski M, Lemmens JA, Koops HS, Molenaar WM. Aneurysmal bone cysts treated by curettage, cryotherapy and bone grafting. JBJS 1997 79B (1): 20-25.
17. Rastogi S, Varshney M K, Trikha V, Khan SA, Choudhury, Safaya BR. Treatment of aneurysmal bone cysts with percutaneous sclerotherapy using polidocanol. A review of 72 cases with long-term follow-up. JBJS 2006; 88B (9): 1212-1216.


Address correspondence to: Dr. Prasad Soraganvi, Dept of Orthopaedics and Traumatology, Meenakshi Mission Hospital and Research Centre, Lake Area, Melur Road, Madurai- 625107, India.

1 Consultant, Dept of Orthopaedics and Traumatology, MMHRC, Madurai.
2 Consultant, Dept of Orthopaedics and Traumatology, MMHRC, Madurai.
3 Senior Resident, Dept of Orthopaedics, DMH, Madurai.

© The Foot and Ankle Online Journal, 2011

Brachymetatarsia: One-Stage Correction using a Cadaver Bone Allograft

by Al Kline, DPM1 , Endolyn Garden, BS, (Hons)2

The Foot and Ankle Online Journal 2 (5): 1

Brachymetatarsia is defined as congenital shortening of the metatarsal caused by premature closure of the epiphysis. The condition most commonly affects the fourth metatarsal of young and adolescent females. Correction of this deformity is either by callus distraction using an external fixator, or by one-stage surgical lengthening procedure using autogenous iliac bone graft. A case of brachymetatarsia is presented that is corrected by one-stage cadaver bone graft sterilized by the Biocleanse ® method. Advantages include complete incorporation of the graft and healing characteristics similar to autogenic bone grafting without the need to harvest graft material.

Keywords: Brachymetatarsia, autogenous, allogenic, bone graft, allograft, biologics, Biocleanse® sterilization process

This is an Open Access article distributed under the terms of the Creative Commons Attribution License.  It permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. ©The Foot and Ankle Online Journal (www.faoj.org)

Accepted: April, 2009
Published: May, 2009

ISSN 1941-6806
doi: 10.3827/faoj.2009.0205.0001


 
The exact etiology of brachymetatarsia is not known. It is thought to be either idiopathic congenital, acquired, or associated congenital. [3] The idiopathic congenital etiology, which refers to the early closure of the epiphyseal plate, is thought to be the most common. The associated congenital etiology is accompanied by other conditions such as Albright’s Syndrome or Down’s Syndrome and parathyroid alterations. Acquired etiology refers to the early closure of the epiphyseal plate after suspected trauma. [3]

A variety of measurements have been described to define brachymetatarsia of the fourth metatarsal. [2,3,4,7] In 2003, brachymetatarsia was diagnosed “when one metatarsal ends 5 mm or more proximal to the parabolic arc”. [7]

In 2004, a morphofunctional study described a more specific measurement called the “angle of fourth metatarsal shortening or second-fourth angle” to quantify the definition of brachymetatarsia. [3] Brachymetatarsia is defined as a second-fourth angle of less than 52.2 degrees in males and 50.5 degrees in females. [3] Using both techniques, in our case report, the fourth metatarsal measured more than 5mm of shortening from the parabolic line and the second-fourth angle is less than 50.5 degrees respectively (45.2 degrees). The parabolic difference is a 10 mm shortening. (See radiograph Fig. 2)

It has been reported that the fourth metatarsal is more likely to be affected by this condition, although many studies vary in their reports. [3,4,10] The majority of cases are seen in females (98:4 female to male ratio respectively) and 72% of these cases occur in both feet. [4] Brachymetapody, a noticeable shortening of the toe, can also present with brachymetatarsia.

Conservative treatments include using metatarsal padding within the shoes. [1] Digital padding and toe splinting may also be attempted. When this is ineffective, surgical correction may be indicated if the patient is experiencing metatarsalgia or have difficulty getting shoes to fit properly. These patients may develop painful calluses, or have a dislocated digit (also known as a “floating toe”). [4] Many patients also express discontent with the appearance of the foot, but this alone is not usually an indication for surgery. [1] However, having the deformity may cause the patient to be overly self-conscious which can lead to psychological issues such as depression. This is particularly important because the abnormality usually presents between the ages of 5 and 14 years in young females. [4]

When surgery is performed, the desired result is to relieve pain and restore functionality. [5] The two methods used most often to correct this condition are gradual distraction using an external fixator, and one-stage surgical lengthening using a bone graft. Gradual distraction involves surgically placing an external fixator on the metatarsal to be lengthened. One-stage lengthening of the metatarsal involves using allograft or autogenous bone, and interposing the graft within the metatarsal. When using an autogenous bone graft, the bone is harvested from the patient’s own body and transplanted into another part of the body. A common site to harvest autogenous bone is the iliac crest. Other sites may also be used, such as the ribs, calcaneus and fibula. [12] An allograft is “any tissue harvested from one individual and implanted into another of the same species [13],” and is used as a substitute for autogenous bone. The allograft bone used in this case were prepared by sterilization and disinfection methods that include gamma irradiation and a low temperature chemical sterilization method known as BioCleanse®. [11]

Case Report

A 13 year old female presents to the office with pain and discomfort involving the left fourth toe. The toe ‘rides up’ on the foot and interferes while wearing closed shoes. (Fig.1)

Figure 1 Initial presentation of brachymetatarsia of the fourth metatarsal.  Typically, the 4th toe is short and contracted due to the immature growth and congenital shortening of the fourth metatarsal at 13 years age.

Radiographic evaluation reveals a congenitally short fourth metatarsal. (Fig. 2 A and B) The patient tried modifying her footwear, but with limited success. At initial visit, the patient was fitted with a digital Budin type splint in an attempt to help plantarflex the digit and eliminate pain. We also initiated dorsal digital padding to protect the toe while in the shoe. Most conservative measures were inadequate and we opted to bring the patient to surgery in order to correct the brachymetatarsia and lengthen the toe.

 

Figures 2A and 2B Radiographs show a typically short fourth metatarsal.  Notice how the fifth toe has rotated in a digital varus orientation.  All epiphyseal growth plates have already closed. (A)  The second-fourth angle measured 45.2 degrees which significantly less than the normal parameter of 50.5 degrees (B) 

The patient has an allergy to Suprax® and is taking Ibuprofen for pain and swelling. The patient has no medical conditions and is young and healthy.

Surgery was discussed with the patient and mother. We described the two options for surgery including callus distraction with an external fixator or a one stage procedure including inter-positional bone graft. Because of her age and health status, we opted for the one stage lengthening. We also described the various types of grafting techniques including autogenous bone grafting from the patient’s own iliac crest to using allogenic, cadaver sterilized bone graft.

Complications of this procedure were discussed including failure of graft material, vascular compromise to the fourth toe and metatarsophalangeal joint stiffness. Two weeks before her surgery, she was asked to manually place distal traction on the toe every night for about 5 to 10 minutes daily.

Surgical Technique

The patient was brought to the operating room. Under sterile technique, a small linear incision was made along the dorsal mid-shaft region of the fourth metatarsal. The extensor tendon was identified and lengthened by standard z-plasty technique. (Figs. 3 A and B)

 

Figures 3A and 3B A small linear incision is oriented along the long axis of the fourth metatarsal. (A)  An extensor z-slide tenotomy is performed to prevent dorsal contracture of the fourth toe during the metatarsal lengthening. (B)

Using blunt and sharp dissection technique, the mid-shaft region of the fourth metatarsal was identified. A small surgical bone saw was used to perform a transverse osteotomy through the metatarsal.

Using a laminar spreader, 2 cm of distraction is placed between the distal and proximal portions of the fourth metatarsal. It is important to gradually place increasing distraction stress through the metatarsal. (Figs. 4 A – C)

  

Figures 4A, 4B and 4C  The mid-shaft region of the fourth metatarsal is exposed taking care to not strip the periosteum from each side of the bone. (A)  A small bone saw is used to perform a transverse osteotomy perpendicular to the long axis of the fourth metatarsal. (B)  A laminar spreader is then used to place a distractive force along the long axis of the fourth metatarsal.  The laminar spreader is slowly spread apart over an hour to eliminate any incidence of vascular compromise. The metatarsophalangeal joint will become inherently stiff during the distraction process.  Plastic deformation of the surrounding tissues is promoted by gradual stress distraction.  (C)

This allows for gradual lengthening of the neurovascular structures of the fourth toe and promotes a gradual plastic deformation of the tissues.

The metatarsal is gradually lengthened over 30 minutes to 1 hour. During this period, the graft can be shaped and prepared for implantation. It is important to realize that the fourth metatarsophalangeal joint will become inherently stiff and rigid during this process. The elastic properties of the surrounding tissues including the joint capsule will slowly begin to deform and relax. A too rapid distraction will cause soft tissue contracture leading to vascular spasm, so gradual distraction is recommended.

During the hour of controlled distraction, the cadaver graft is prepared. It is important, when preparing the graft, that one take bone approximating the thickness and length of the metatarsal. We chose to use a humoral graft and cut a 20 mm section to approximate the size and shape of the metatarsal. Although the metatarsal gap measured and desired length is measured at about 10 mm on radiograph, a larger graft is recommended to be initially used. The graft is easier to handle and drill, then can be remodeled to a smaller size prior to insertion.

Once the graft is to the desired shape, a .062mm Kirschner wire is used to drill a hole along the long axis of the graft. This is called pre-drilling the graft. This graft was completely cortical. Pre-drilling the graft will allow for easier placement in the final stages of the operation.

Once the graft is prepared, blood is drawn from the patient and a platelet and white blood cell concentrate is prepared and placed on the back table. The graft is then placed in the concentrate slurry while completing the distraction process. (Figs. 5 A – C)

  

Figures 5A, 5B and 5C  The allograft is cut directly from a hard cortical section of humeral cadaver bone. (A)  Once the bone is shaped, the graft is pre-drilled along the long axis of the bone to prepare for interpositional insertion of the graft to the fourth metatarsal. (B)  While the laminar spreader is distracting the bone, once the graft is ready, it can remain in the platelet and white blood cell concentrate taken from the patient’s own blood. (Biomet® Bioorthologics GPS® III)

When the distraction process is complete, the graft is now ready for placement. This stage can be technically challenging due to the persist tightness of the confined space. The graft often has to be re-shaped or slightly shortened for proper placement. That is why it is important to properly measure the distance of distraction prior to graft placement.

At this point the laminar spreader is removed and the wire is reverse drilled along the distal portion of the metatarsal through the digit. The bone must be angled and care must be taken to not plantarflex the digit too much once pinned.

Once the k-wire is in proper alignment, the graft is carefully inserted within the metatarsal. The most challenging aspect of this surgery is aligning the pre-drilled hole with the k-wire and through-drilling to the most proximal segment of the fourth metatarsal. (Figs. 6 A-C)

  

Figures 6A, 6B and 6C  The laminar spreader is removed after an hour of distraction.  The mini c-arm is used to determine the proper amount of distraction to attain the proper metatarsal length and parabola. (A)  The k-wire is directed distally first.  The bone is angulated and then drilled through the fourth digit. (B)  The graft is then interposed within the fourth metatarsal, drilled and stabilized with a .062 k-wire.  (C)

Once the graft is in place, the remaining platelet and white blood cell slurry is lavaged into the wound prior to closure. A small Jergen’s® ball is placed on the k-wire and the foot is then dressed in a smile gauze dressing and placed non-weight bearing in a posterior leg splint. (Figs. 7 A – C)

  

Figures 7A, 7B and 7C  Once the graft is securely in place, the patient’s own platelets and white blood cells are lavaged into the wound. (A and B)  The pin is protected with a Jergen’s® ball at the end of the k-wire and closed prior to application of dressings and a posterior leg splint. (C)

After 2 weeks in a posterior splint and when the sutures are removed, the patient is placed in a short leg fiberglass cast for an additional 6 weeks. The entire immobilization period is about 8 weeks before partial to full weight bearing can resume. Radiographs performed at the end of 8 weeks reveals solid and complete incorporation of the graft along the metatarsal shaft.

The patient has now been seen over the last year without pain or complication to the graft. The toe actually moves without any stiffness to the metatarsophalangeal joint on range of motion. She is very pleased with her surgical outcome. (Figs. 8 and 9)

Figure 8   At 8 weeks, the bone graft shows signs of bone interposition and callusing. Deformation stress is noted along the proximal half of the 4th metatarsal, but does not compromise the overall shape of the metatarsal.

Figure 9  After 6 months, the patient is very pleased with the restoration of metatarsal and toe length.  There is excellent fourth metatarsophalangeal joint range of motion without pain or discomfort.

Discussion

The author’s have found the use of an allogenic bone graft to have the same characteristics and properties as autogenous bone in one-stage metatarsal lengthening procedures, but without the need to harvest bone graft from the patient. They both have osteogenic, osteoconductive and osteoinductive properties. [18] Osteogenic properties refer to the properties that promote the synthesis of new bone. Osteoconductive properties are those properties of the graft that provide framework where the formation occurs. Finally, osteoinduction is the ability of the graft to “stimulate the host precursor cells to form new bone through differentiation into chondroblast or osteoblast”. [18] One of our concerns before surgery was whether the graft would incorporate as normal bone.

As previously mentioned, there are two techniques commonly used to treat brachymetatarsia: gradual distraction with external fixation and one-stage lengthening using bone grafts.

The first method involves applying an external fixator that is used to gradually lengthen the bone. This is achieved by surgically placing the fixator into the metatarsal that is to be lengthened. About a week post-operatively, the lengthening begins at a rate of ¼ mm four times per day for a total of 1 mm per day. [2] This may take place over a period of several weeks. [5] After the desired result is achieved, the fixator remains static for twice the amount of time it took to perform the distraction, during which time the patient remains non weight-bearing. [5] The patient typically can tolerate full weight bearing once the fixator is removed. [2] The reported advantage to this technique is the soft tissues and neurovascular structures are lengthened at the same time the bone is being lengthened. This tends to maximize the ability of the metatarsal to lengthen. [2]

There are complications that could arise when using gradual distraction over a longer period, but this appears to be more associated with the external fixator. Some of these include hyper-pigmentation around pin sites, pain during distraction, stiffness, decreased range of motion, scarring, deformities, joint dislocation, prolonged bone consolidation and pin-track infections. [1,2,5,8]

One-stage lengthening is a process where autogenous or allograft bone is grafted to lengthen the metatarsal. The advantages of this procedure include a shorter bone consolidation period, smaller incision, and less morbidity. [8,10] Some of the disadvantages and complications involved with autogenous bone grafting include technical difficulty, neurovascular damage, small gain in length, and donor site morbidity. [8,10]

It appears that gradual lengthening in the operating room using a laminar spreading and applying distraction stress gradually over 30 minutes to 1 hour will not cause vascular compromise.

A number of studies have been reported on the viscoelastic properties of the surrounding soft tissues during metatarsal lengthening. [4,10] Stress relaxation will promote a lengthening of soft tissue when gradually performed, even in a relatively short period of time. A too rapid distraction of surrounding tissues will cause more contracture and vascular spasm with tissue compromise. Using this gradual distraction technique with a simple laminar spreader, we were able to achieve over 10mm of lengthening within an hour without vascular compromise to the toe.

Allogenic and autogenous bone grafts have similar properties including bone healing characteristics and incorporation rates. The process of bone healing occurs in four stages; inflammation, soft callus formation, hard callus formation and bone remodeling. During the first stage, there is bleeding at the site which results in a hematoma. Inflammatory cells then penetrate the hematoma to fight infection, secrete cytokines and growth factors and promote clotting. In the next stage chondrocytes and fibroblast produce a soft callus to provide mechanical support and a template for the bony callus. The third stage is where most of the osteogenesis occurs. There is a high level of osteoblastic activity and formation of mineralized bone. The soft callus is slowly removed and revascularization occurs. [20] In the final stage, remodeling of the bone occurs, blood circulation to the area improves and the bone becomes compact. Complete bone healing takes 6 – 8 weeks, although factors such as movement, smoking, poor nutrition, age and disease can affect the healing rate. [21]

An advantage to allogenic bone grafting is that there is no need to harvest bone from the patient, thus there is no donor site and a second surgery site. Having a second surgery site, or in this case, a donor site can potentially make surgery more complicated, and increase the risk of infection as well as creating increased pain along the donor site. It is very common for the donor site to be more painful after surgery than the recipient site, especially at the iliac crest. With allogenic bone, there is no donor site pain, no type matching or rejection, and the allogenic bone can be pre-shaped to decrease the surgery time. [16]  To our knowledge, this is the first reported successful correction of brachymetatarsia with complete incorporation of a cadaver allograft using the Biocleanse® sterilization process.

The BioCleanse® Sterilization Process

The BioCleanse® sterilization process is used by Regeneration Technologies to prepare allograft tissue for surgical uses. These implants are used in spinal, sports medicine, general orthopedic, cardiovascular, and dental surgeries. [17] Before any tissue is used, a medical and social history of the donor is obtained from the donor’s family. The tissue is then inspected and screened for diseases (such as HIV and hepatitis). [15] Upon approval, the tissue enters into the automated sterilization process. [14] In the first step of the sterilization process blood, lipids, and marrow are removed from the bone via a vacuum/pressure process to reduce the risk of immune response in the recipient. Next, chemical sterilants are used to eliminate pathogens. This process is designed to go deep within the tissue matrices to eliminate pathogens such as bacteria, viruses, and fungi. Finally, the germicides are removed, and the tissue’s biocompatibility is preserved in the process. [13] In order to ensure a low contamination rate, surface sterilization is incorporated during final packaging through low doses of gamma irradiation or hydrogen peroxide gas plasma. [13]

Mroz, et al., in analyzing the biomechanical properties of allograft bone treated by the sterilization process concluded “Sterilization of allograft bone with Biocleanse® does not significantly alter the mechanical properties when compared with untreated samples. The effect of this sterilization process on the osteoconductive and osteoinductive properties of allograft bone must be determined.” [22]
In this case report, it appears the allograft incorporated well within the surrounding bone and tissue and provided this patient with adequate bone lengthening without the need for autogenous bone harvest.

References

1. Gilbody J, Nayagum S: Lengthening of the first metatarsal through an arthrodesis site for treatment of brachymetatarsia: A case report. Journal of Foot Ankle Surgery. 47 (6): 559 – 564, 2008.
2. Houshian S, Skov O, Weeth R: Correction of congenital brachymetatarsia by gradual callus distraction. Scand J of Plast Reconstr Surg Hand Surg. 36 373 – 375, 2001.
3. Pedro V. Munuera Martínez PVM, Guillermo Lafuente Sotillos G, Domínguez Maldonado G, Luis Salcini Macías J, Martínez Camuña L: Morphofunctional Study of Brachymetatarsia of the Fourth Metatarsal. J Am Podiatric Assoc . 94 (4) 347-352, July-Aug. 2004.
4. Goforth W. et al Brachymetatarsia of the Third and Fourth Metatarsals. J Am Podiatric Assoc. 91 (7) 373-378, 2001.
5. Wilusz P, Van P, Pupp GR: Complications associated with distraction osteogenesis for the correction of brachymetatarsia: A review of five procedures. J Am Podiatric Assoc. 97 (3) 189 – 194, 2007.
6. Allmendinger A, Yeghiayan P, Perone R, St. Vincent’s Medical Center in New York City: Case of the month. diagnostic imaging 31( 1) [online] Accessed February 7, 2009.
7. Kim HT, Lee SH, Yoo CI, Kang JH, Suh JT: The Management of Brachymetatarsia. Journal of Bone Joint Surgery. 85B (5) 661 – 665, 2003.
8. Kim J, Baek GH, Chung MS, Yoon PW: Multiple Congenital Brachymetatarsia: One-Stage Shortening and Lengthening Procedure Without Iliac Bone Graft. Journal of Bone Joint Surgery. 86B (7): 1013 – 1015, 2004.
9. Bone Graft Alternatives. North American Spine Society [online]Assessed February 15, 2009.
10. Baek GH, Chung MS: The Treatment of Congenital Brachymetatarsia by One-Stage Lengthening. Journal of Bone Joint Surgery. 80B (6): 1040 – 1044, 1998.
11. (2003) BioCleanse Tissue Sterilization :Sterilization Validation. Regeneration Technologies, Inc. [online] Accessed March 21, 2009
12. Finkemeier C. Bone-Grafting and Bone-Graft Substitutes. Journal of Bone Joint Surgery. 84A (3): 454-463, 2002.
13. Bostrom MPG, Seigerman DA: The Clinical Use of Allografts, Demineralized Bone Matrices, Synthetic Bone Graft Substitutes and Osteoinductive Growth Factors: A Survey Study. Hospital for Special Surgery, 2005 [online] Accessed March 21, 2009.
14. No author: A New Standard for Tissue Sterility. Regeneration Technologies (2006) [online] Accessed March 21, 2009.
15. No author: From Donation to Implantation. Regeneration Technologies (2006) [online] Accessed March 21, 2009.
16. No author: Biologics vs. other materials. Regeneration Technologies (2006) [online] Accessed March 21, 2009.
17. No author: Biologics Implants. Regeneration Technologies (2006) [online] Assessed March 21, 2009.
18. Sen MK, Miclau T: Autologous Iliac Crest Bone Graft: Should it Still be the Gold Standard for Treating Nonunions?. Injury. 38 (1) S75-S80 2007.
19. Malay DA: Closer look at bone graft substitutes. Podiatry Today (18) 1 Sept, 2005 [online] Accessed April 15, 2009
20. Schindeler A, et al Bone Remodeling During Fracture Repair: The Cellular Picture. Seminars in Cell & Developmental Biology 19: 459 – 466, 2008
21. No author: Bone Healing (2008, May 26). American College of Foot and Ankle Surgeons [online] Accessed April 15, 2009.
22. Mroz TE, Lin EL, Summit MC, Bianchi JR, Keesling JE Jr, Roberts M, Vangsness CT Jr, Wang JC: Biomechanical analysis of allograft bone treated by novel tissue sterilization process. Spine Journal 6 (1): 34 – 39, 2006.


Address correspondence to: Al Kline, DPM
3130 South Alameda, Corpus Christi, Texas 78404.
Email: al@kline.net

Adjunct Clinical Faculty, Barry University School of Podiatric Medicine. Private practice, Chief of Podiatry, Doctors Regional Medical Center. Corpus Christi, Texas, 78411.
2  Texas A&M Graduate (Hons), Corpus Christi, Texas, Incoming first year student, Barry University School of Podiatric Medicine.

© The Foot and Ankle Online Journal, 2009