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Freiberg’s Infraction of the Second Metatarsal Head with Bioorthologic Repair using the NEXA Osteocure™ Bone Graft: A case report

by Al Kline, DPM1

The Foot & Ankle Journal 1 (11): 4

Freiberg’s infraction is a relatively common osteochondritis of the second metatarsal head. It appears to affect young women who are active in sports. Its etiology is thought to be traumatic in nature causing a painful alteration, subchondral disruption and collapse of the articular cartilage. A case report is presented describing this disorder in a young female runner. The use of a bioorthologic bone plug to surgically treat this condition is discussed and presented. It appears that the use of bioorthologic materials provide a promising alternative to surgical osteotomies. It has been shown that bioorthologic materials will provide a porous scaffold allowing blood, marrow and progenitor cells to wick into the pores and provide a stable environment for tissue in-growth and cellular development. Between six and twelve months, the polymer is resorbed and replaces the natural hyaline cartilage of the joint surface.

Key words: Freiberg’s infraction, osteochondritis, osteochondritis dessicans, bioorthologic bone graft

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 & Ankle Journal (www.faoj.org)

Accepted: October , 2008
Published: November, 2008

ISSN 1941-6806
doi: 10.3827/faoj.2008.0111.0004

In 1914, Alfred H. Freiberg was the first to describe a painful collapse to the articular surface of the second metatarsal head. [1] The etiology of injury can be attributed to trauma and subchondral disruption of the vascular supply to the articular cartilage. The incidence of injury appears to be most commonly found in young women and girls, although the overall incidence of osteochondroses is higher in men. [2] On occasion, the third metatarsal head may also be involved. Osteochondritis, in effect, can involve any of the five metatarsal heads of the foot. However, the incidence is highest involving the second metatarsal head. [1]

There does not appear to be a genetic link to Freiberg’s infraction, although a recent report of Freiberg’s infraction in twins may suggest an underlying genetic predisposition. [8]

In Freiberg’s original article, he described six women with a painful limp and pain isolated to the second metatarsal head. Radiographs revealed collapse of the articular surface of the second metatarsal head with intra-articular loose bodies seen in three of the six patients. He noted that four of the six patients were under 18 years of age and postulated that a long second metatarsal combined with an ineffective first ray complex attributed to overload of the second metatarsal phalangeal (MTP) joint and subsequent articular collapse. [2]

Patients usually present with a painful and often swollen joint. A history of trauma may or may not exist. There is usually point tenderness to the dorsal aspect of the second metatarsophalangeal joint and associated limitation of joint motion. Diagnosis is often confirmed by simple radiographs which show varying stages of metatarsal head injury and articular depression.

MR (magnetic resonance) imaging has been definitively shown to aid in the diagnosis of Freiberg’s infraction before joint changes occur on radiograph. [4] This may be particularly useful in the early stage of the disorder when joint pain is present without observed changes to the joint surface.

In the patient with a normal or even wide joint space, MR imaging allows for early identification of Freiberg’s infraction through low signal intensity changes of subchondral sclerosis. (Fig. 1)

Figure 1 Early flattening (small arrows) with low signal intensity osteochondrosis of the second metatarsal head on a T-1 axial image.  (Courtesy David W. Stoller, MD: Magnetic Resonance Imaging in Orthopaedics & Sports Medicine, pp.488-489, 1993.)

In his original article, Freiberg described his treatment which included simple removal of the loose bodies in the joint. Historically, there have been a number of surgical approaches to the treatment of Freiberg’s infraction. The use of bioorthologics is a relatively new approach to the treatment of osteochondral defects and injury. A case report is presented describing the use of the NEXA Osteocure™ bone graft for repair of a stage II Freiberg’s infraction of the second metatarsal head.

Case Report

An active fifteen year old female runner began having pain and discomfort to the second MTP joint. She did not recall any injury. She is very active in track and basketball. She has been running daily and relates to pain while running. She was using a silicone sleeve over the second toe and takes Tylenol and Motrin for pain and swelling. Her pain began to interfere with her running and she began seeking medical attention.

Her clinical examination revealed a swollen second metatarsophalangeal joint with pain upon dorsiflexion of the second toe. Joint range of motion was limited to about 5 to 10 degrees of dorsiflexion with extreme pain. Radiographic evaluation confirmed second metatarsal head changes consistent with Freiberg’s infraction and a long second ray with Morton’s toe. (Fig. 2)

Figure 2   Initial radiograph shows subchondral disruption of the articular surface of cartilage involving the second metatarsal head.  Note the long second metatarsal and Morton’s toe. 

She underwent MR imaging which revealed diffuse increased signal intensity with local tissue edema and hemorrhage. There was joint effusion with fragmentation of the metatarsal head consistent with Freiberg’s infraction, stage II.

The patient had a track meet within three weeks of our visit and returned about four weeks later and underwent casting and immobilization. After cast immobilization, she was placed in accommodative metatarsal padding and shoes and was asked not to return to running for an additional month. However, she continued to re-develop pain and swelling to the joint and was scheduled for surgery to include osteochondral bone repair with bioorthologic graft using the NEXA Osteocure™ bone graft.

Surgical Technique

The patient was brought to surgery. A local second ray block was performed under intravenous sedation. A small incision was made directly over the second MTP joint. A dorsal capsular incision was performed and upon entry of the joint, we noticed a cartilaginous loose body at the dorsal aspect of the metatarsal head. (Fig. 3)

Figure 3 Once the joint is entered surgically, a dorsal linear capsulotomy reveals a loose joint body.

The soft tissue capsule is delicately reflected to expose the cartilaginous surface of the metatarsal head. A large defect along the dorsal half of the metatarsal head is identified. The cartilage was actually separated from the underlying subchondral bone.

Using a small scalpel, the defect is lifted from the subchondral bone. It is important to identify the loose margin of cartilage and the point of firm attachment of the cartilage cap plantarly in order to preserve the plantar cartilage. (Figs. 4 and 5) Once this margin is identified, the loose cartilage is then excised in a semi-circular fashion. This is done to facilitate the bone plug, which is round in its shape. (Figs. 6 and 7)

 

Figures 4 and 5  The loose cartilage is identified and demarcated from the subchondral bone.  Care is taken to identify the plantar cartilaginous attachment.

 

Figures 6 and 7  The loose cartilage is removed and the  plantar cartilaginous attachment is identified.  A semi-circular excision of the cartilage flap has been performed.

A curette is then used to remove the soft, unhealthy subchondral bone. (Fig. 8) Preparation of the site is probably the most crucial aspect of this surgery. In particular, joint range of motion needs to be unimpeded dorsally and requires the removal of joint spurring, loose bodies and bone defects. Using the NEXA Osteocure™ Implant Kit, a corresponding set of color-coded sizers allows for determination of the bone graft size.

Figure 8   A curette is used to remove any diseased subchondral bone.  The diseased portion of bone is usually softer than the underlying cancellous bone.

Color coded sizers of 5, 7, 9 and 11mm diameter correspond to the respective graft size plugs. (Figs. 9,10) Once the graft size is determined, a reaming drill is used to prepare the graft site for implantation. (Figs. 11,12 and 13) The graft is then measured for depth, inserted and tapped within the newly prepared host site. (Figs. 14,15 and 16) The graft is then firmly placed into the host site. The joint can also be placed through its proper range of motion. This will ensure that the graft is articulating with the proximal phalanx. (Figs. 17 and 18)

 

Figures 9 and 10  The bone plug sizer is used to determine the size diameter of the graft.  Again, the inferior, semi-circular portion of healthy cartilage should fit directly to the sizer.

  

Figures 11,12 and 13  The drill corresponding to the sizer is used to prepare the host site for the graft plug.

  

Figures 14,15 and 16  The graft is measured for depth and then inserted into the host site.  A small tap is used to secure the graft into the host site.

 

Figures 17 and 18  The graft is seated in the defect.  The Osteocure™ graft provides a press fit to the defect with close approximation to the surrounding bone and tissue causing migration of tissue into the scaffolding.  This surface will provide scaffolding for hyaline-like cartilage in 6 to 12 months.

The surgical site is then closed in the customary manner. The patient was then placed non-weight-bearing in a posterior splint and kept on crutches for 4 weeks. This was followed by 2 weeks of partial weight-bearing in a walking shoe. She was able to wear her athletic shoes within 8 weeks after surgery.

The patient was pain free with an increase in joint range of motion. At last visit, she was playing volleyball without pain. (Figs. 19 and 20), however, the patient has been advised not run for six months after surgery to allow the graft to resorb.

 

Figures 19 and 20  Two months following surgery, incorportation of the graft is already seen.  A thin articular margin is also appreciated.  Although, there is still some flattening of the metatarsal head, the patient is now asymptomatic.  A close up of the radiograph (Fig. 20) reveals new subchondral bone formation in a cancellous pattern with metatarsal head resurfacing.

Discussion

Several synonyms have been used to described Freiberg’s infraction including Freiberg’s infarction, osteochondrosis of the second metatarsal head, eggshell fracture, Koehler second disease, peculiar metatarsal disease, Panner disease of the metatarsal, osteochondritis deformans metatarso-juvenilis, malacopathia, subchondral bone fatigue fracture of the second metatarsal head and dorsal fatigue stress injury of the second metatarsal head. [2,7]

In the majority of cases, the defect is usually dorsally located to the upper half of the articular surface of the metatarsal head. This would also lend support to the etiology of trauma causing this defect. In observing a number of these cases, mechanical changes appear to cause a dorsal articular jamming and trauma to the joint surface. These include a Morton’s toe or long second digit, a short first metatarsal or elongated second ray and instability of the first ray. Limitation of dorsiflexory motion of the second MTP joint will lead to progressive joint damage and eventual articular shear. This will cause an actual lifting and separation of the articular cartilage from the subchondral bone disrupting the vascular supply to the articular cartilage.

Once the articular cartilage separates, the cartilage can fragment. The fragments that separate from the articular cartilage are called joint bodies or joint ‘mice’.

As previously stated, ‘infraction’ is sometimes called Freiberg’s ‘infarction’. Infarction would suggest a vascular event leading to osteonecrosis. It has been suggested that avascular necrosis from injury will lead to the growth plate or epiphyseal injury in young, growing bone. This may also explain why the incidence is higher in young women and girls.

In 1959, Braddock observed that there is a relative weakness of the second metatarsal epiphysis at a certain stage of epiphyseal maturation. [3] Whatever the etiology, the result appears to cause cartilage lifting and separation from the underlying subchondral bone and vascular osteonecrosis of the joint surface.

The extent of articular damage however, appears to be directly proportional to the extent of joint pain. Treatment, including both conservative and surgical approaches, varies to the extent of injury. In early stages, where the articular cartilage may form a small depression, treatment usually consists of immobilizing the joint.

Conservative treatments should almost always consist of immobilization, offloading and casting irrespective of severity and stage. The goal of non-operative immobilization is to promote a decrease in joint effusion and inflammation including the surrounding soft tissue structures. This may be supplemented with NSAID therapy, joint injections and oral steroids. In patient’s who may not want surgery, shoe modification, metatarsal bars, orthotics and even rocker bottom shoes may provide some temporary relief. In a majority of cases, operative intervention is recommended to provide improved joint mechanics, remove damaged joint spurs and loose joint bodies and treat the osteochondral defect.

Methods of Surgical Treatment

Freiberg initially described removal of the loose bodies to the affected joint. Other treatments have been more aggressive, including the actual removal of the metatarsal head. Unfortunately, this will lead to more complicated conditions of the foot including transfer metatarsalgia, stress fracture and contracture of the corresponding digit.

Some authors have also suggested joint arthroplasty and resecting the base of the proximal phalanx. [6] This may decompress the joint, but joint instability and toe shortening or dorsiflexory rotation of the digit is a major complication.

In 1991, Smith, et al., described simple decompression osteotomy using a T-plate in 15 patients with Freiberg’s infraction of the second metatarsal head. They reported good results and relief of pain within 12 months, although all patients had limited motion of the joint post-operatively. [5]

Dorsiflexory osteotomies have also been described in order to rotate the healthy plantar cartilage dorsally. This is commonly performed by a v-osteotomy and use of cross K-wire technique or screw fixation. However, rotational osteotomies are only indicated in Freiberg’s stages I-III where the plantar hinge of the cartilage is still intact. Implants have also been used including silastic and titanium total implants and titanium hemi-implants. Shih, et al., described the successful use of a titanium hemi-implant in the treatment of Freiberg’s infraction. They reported a successful increase in range of motion of the joint from 15 degrees to 45 degrees, with no pain or activity limitation. [6]

The advantage of using bioorthologics in the treatment of osteochondral defects

Newer techniques are now being introduced in an attempt to actually repair the damaged cartilage and subchondral bone in Freiberg’s infraction. Orthobiologic materials, particularly PolyGraft™ materials, provide a scaffolding for regeneration of tissue and have demonstrated evidence of resurfacing the articular cartilage with hyaline-like cartilage. This is different than resurfacing of the joint with fibrocartilage after damage. Fibrocartilage is primarily Type I collagen and is less desirable than Hyaline cartilage, which is primarily comprised of type II collagen. In a recent land-mark study, Cascio, et al., reported exciting chondral repair with observed hyaline cartilage in a goat model using an injectable hydrogel bone graft. [8]

Critical size chondral defects were created on the stifle joint of adult goats. Experimental defects underwent marrow stimulation to recruit reparative stem cells and were primed with a chondroitin-sulfate based adhesive to anchor the scaffold. Controls received marrow stimulation alone.

The operative goat legs were cast for two weeks and after 13 weeks, cartilage fill and repair quality was assessed by histomorphometry evaluation. Results revealed evidence of hyaline-like repair with a 12% increase in total tissue fill in scaffold-treated defects on histomorphometry. Remodeling and articular cartilage bridging was seen up to twelve months after implantation.

This is an exciting development in the treatment of osteochondral defects by actually healing the cartilage defect with desirable hyaline cartilage and will maintain the joints normal cartilaginous properties. The Osteocure™ bone plug is a porous PolyGraft™ and is the first 100% resorbable composite scaffold material designed to fill osteochondral defects. Its properties include a three dimensional scaffolding structure for tissue incorporation and remodeling. Resorbable polymers and bioactive ceramics are combined to produce the desired strength, stiffness and bone growth characteristics. It also withstands mechanical loads and compression without crushing the material. The Osteocure™ graft provides a press fit to the defect with close approximation to the surrounding bone and tissue causing migration of tissue into the scaffolding. The hydrophilic properties of the porous scaffolding allow blood, marrow and progenitor cells to wick into the pores and provide a stable environment for tissue in-growth and cellular development. Between six and twelve months, the polymer graft is resorbed and replaced with living tissue. [9]

Conclusion

Although there is no one consensus on the best surgical treatment for this condition, the use of orthobiologics provides a promising new attempt to restoring the cartilaginous surface of the joint and eliminating joint destruction and pain. More importantly, these products appear to heal and replace the natural hyaline cartilage of the joint surface.

References

1. Freiberg, AH. Infraction of the second metatarsal head, a typical injury. Surg Gyn Ob, (19) 163-191, 1914.
2. Boyer, M., DeOrio, J. Freiberg Infraction. E-Medicine, Online article, 2004.
3. Braddock GTF. Experimental epiphyseal injury and Freiberg’s disease. JBJS, 41B (1) February, 1959.
4. Stoller DW. Magnetic Resonance Imaging in Orthopaedics and Sports Medicine. J.B. Lippincott Company, Philadelphia, 1st edition, 1993.
5. Smith TW, Stanley D, Rowley DI. Treatment of Freiberg’s disease: A New Operative Technique. JBJS 73B (1), January, 1991.
6. Shih AT, Quint RE, Armstrong DG, Nixon BP. Treatment of Freiberg’s infraction with the Titanium hemi-implant. JAPMA 94 (6), 590-593, Nov/Dec 2004.
7. Blitz NM, Yu JH. Freiberg’s infraction in identical twins: A case report. JFAS, 44(3), May/June 2005.
8. Cascio B, Sharma, MS, Fermanian, BS, Elisseeff, J: Chondral lesion repair in a critical size defect model using injectable hydrogel scaffold in conjunction with marrow stimulation. AOSSM, Poster #32, 2006.
9. Nexa Orthopaedics: Osteocure: PolyGraft™ Material Technology. [Online PDF]


Address correspondence to: Al Kline, DPM
3130 South Alameda, Corpus Christi, Texas 78404.

1 Adjunct Clinical Faculty, Barry University School of Podiatric Medicine. Private practice, Chief of Podiat ry, Doctors Regional Medical Center. Corpus Christi, Texas, 78411.

© The Foot & Ankle Journal, 2008

Talar Osteochondral Defect Grafting with Nexa Orthopedics OsteoCure™ Bone Graft Plug

by Jonathan Sharpe, DPM1, Mark A. Hardy, DPM, FACFAS2

The Foot & Ankle Journal 1 (6): 1

Osteochondritis dessicans of the ankle is a condition often encountered by the foot and ankle physician. Many treatments have been described in the literature including cast immobilization, arthroscopic debridement, open debridement, and autogenous grafting. The NEXA OsteoCure™ bone graft plug allows for immediate lesion excision while avoiding the morbidity associated with obtaining an autograft. The authors provide a brief review of talar dome lesions including staging and classification and their experience and technique involved for utilizing NEXA Orthopedics OsteoCure™ bone graft plugs.

Key words: Osteochondritis dessicans, Talus, Talar dome lesions, NEXA Orthopedics OsteoCure™ bone graft plugs

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 & Ankle Journal (www.faoj.org)

Accepted: May 2008
Published: June 1st, 2008

ISSN 1941-6806
doi: 10.3827/faoj.2008.0106.0001

Osteochondral defects of the talar dome, aka osteochondritis dissecans, are common pathological entities encountered by the podiatric physician. Although trauma is thought to play a primary role in the genesis of these lesions, idiopathic osteonecrosis may also be a cause. Subjectively, these patients frequently present complaining of a deep, aching, non-descript pain in the ankle joint that worsens with activity.

Clinical examination may reveal joint line tenderness, effusion, as well as pain upon ankle joint range of motion. Diagnosis is frequently made with imaging after high clinical suspicion, and the lesions are typically seen anterolaterally or posteromedially. (Fig. 1)

Figure 1   Diagnosis of osteochondral defects are often made with CT scans.  The lesions are typcially seen anterolaterally and posteromedially.

Insight into the morphology and mechanism of action of these lesions was illustrated in a retrospective study of thirty-one ankles in twenty-nine patients with osteochondral lesions by Canale, et al. [1] It was found that lateral lesions were associated with inversion or inversion-dorsiflexion trauma and that these lesions are morphologically shallow and anteriorly located on the talar dome. Lateral lesions were more likely to become displaced in the joint and to have persistent symptoms. Medial lesions were both traumatic and atraumatic in origin, morphologically deep, located more posteriorly on the talar dome, and less symptomatic. These typically occurred with a plantarflexion and inversion type of injury. [1]

With an acute injury, the osteochondral lesion may not be visible on the initial radiographs. If there is a high index of suspicion, repeat radiographs in two to four weeks should be obtained or one should consider more advanced imaging. In a study by Anderson, et al., it was found that when plain radiographs of the ankle are relied on for the diagnosis of an osteochondral fracture of the talus, many lesions remain undiagnosed. [2] Stage-I osteochondral fractures show no diagnostic changes on plain radiographs, and Stage-II lesions are usually subtle and, therefore, are often overlooked by both radiologists and clinicians. The most commonly used classification system for these injuries was created by Berndt and Harty. [3]

A type I lesion represents a small area of compression. A type II lesion is a partially detached osteochondral lesion. When the lesion becomes completely detached, but remains in its anatomical location, it is a type III lesion. A detached lesion with any movement or migration is classified as type IV. A CT may offer more accurate staging of the lesion, although classification may not correlate with intraoperative findings. (Fig. 2)

Figure 2   The CT may offer more accurate staging of the lesion, although classification may not correlate with intraoperative findings.  

Pettine, et al., evaluated seventy-one osteochondral fractures of the talus for an average of 7.5 years after the onset of symptoms to determine which factors influenced the final result. It was found that the type of fracture was the most important factor and that delay in treatment also affected the results adversely. [4]

In the study by Canale, et al., using the classification system of Berndt and Harty, it appeared that Stage-I and Stage-II lesions should be treated non-operatively, regardless of location. Stage-III medial lesions should be treated non-operatively initially but if symptoms persist, surgical excision and curettage are indicated. Stage-III lateral lesions and all Stage-IV lesions should be treated surgically and early. Long-term results indicated that few lesions unite when treated non-operatively. Degenerative changes in the ankle joint, whether symptomatic or not, were common regardless of the type of treatment. [1]

Non-operative treatment of these lesions includes casting and immobilization. There is no evidence, however, that these patients need to be immobilized if they are kept non-weight bearing. There is also no evidence that a non-weight bearing cast offers better results than a weight bearing cast.

A retrospective study of 22 ankles in 22 patients with osteochondral talar dome lesions between 1975 and 1983 indicated that surgical treatment yields superior results to conservative therapy. [5] Many of these lesions are treated surgically with arthroscopic joint examination and debridement of the lesion. This process may be aided by an external joint distracting device. Anterolateral lesions are typically more amenable to arthroscopic debridement than posteromedial lesions because of their anatomical location. In a study by Kumai, et al., the authors found good clinical results in arthroscopic debridement and k-wire drilling of lesions in patients who were younger than sixty years old.6 Posteromedial lesions typically necessitate an osteotomy of the medial malleolus for exposure, with open reduction and internal fixation and subsequent prolonged non weight-bearing. (Fig. 3)

Figure 3   Posteromedial lesions typically necessitate an osteotomy of the medial malleolus for exposure.  Here,  ORIF screws are placed through the medial malleolus following the procedure.  

We have employed the NEXA Orthopedics OsteoCure™ Bone Graft Plug with success for surgical repair of talar osteochondral lesions. The OsteoCure™ Plug is a cylindrical implant ideal for filling defects in bone.

The implant is a resorbable, porous scaffold, which allows the in-growth of new healing tissue. The implant is sized for cylindrical defects with a minimum depth of 5 mm and a maximum depth of 12 mm. Careful pre-operative planning should be taken to ensure adequate visualization of the defect to be grafted. An osteotomy may need to be employed to ensure sufficient access to the lesion.

Surgical Technique

The following described technique has been outlined from NEXA’s surgical technique literature. The OsteoCure™ Plug Implant Kit contains the cylindrical implant, the delivery device, and a trimming knife. This is to be used with the accompanying OsteoCure™ Plus Site Preparation Kit. (Fig. 4)

Figure 4    The OsteoCure™ Plug Implant Kit contains the cylindrical implant, the delivery device and the trimming knife.  This is to be used with the accompanying OsteoCure™ Plus Site Preparation Kit.  

The standard implant depths range from 5 mm to 12 mm, but longer implants are available. The implants also come in a variety of diameters to suit the varying sizes of these lesions. The color-coded instrument set comes in 5, 7, 9, and 11 mm to correspond to the accompanying OsteoCure™ implant sizes. Once adequate visualization and access of the talar lesion has been obtained, a thin walled drill sleeve is introduced to the talar dome, taking care to encompass the entire lesion. (Figs. 5-7)

  

Figures 5,6,7   Once the osteochondral defect is identified, a thin walled sleeve drill is introduced to the talar dome.

Prior to insertion, an appropriately sized obturator is introduced into the handle of the drill sleeve for ease of insertion. The drill sleeve is then gently introduced through the cartilaginous surface by pronating and supinating the device. Once the drill sleeve has been slightly advanced, remove the obturator from the drill sleeve. The depth can easily be measured on the drill sleeve, which is calibrated in millimeter measurements. Care must be taken to insert the drill sleeve in a manner perpendicular to the articular surface to ensure that the graft lies flush after insertion. Next, the metallic cap is removed while maintaining the drill sleeve at the desired depth. The corresponding drill is then introduced into the drill sleeve and the lesion is drilled to the desired depth. (Fig. 8)

Figure 8   Care is taken to insert the drill sleeve and drill in a manner perpendicular to the articular surface to ensure that the graft will lie flush after insertion.  

Continue drilling until the drill stop contacts the drill sleeve. The drill and drill sleeve are then both removed from the surgical field. (Fig. 9)

Figure 9   The talar dome defect is now drilled and prepared for grafting.

Next, the cylindrical graft is prepared. The graft comes housed in a delivery device. The device has a plunger on the opposite end of the graft. The plunger end should be introduced into the lesion and pressed firmly into place. This will force the graft out of the proximal end of the delivery device, effectively sizing the implant. (Fig. 10)

Figure 10   The plunger end of the device is introduced, effectively sizing the implant.

The delivery device is then removed from the field and the redundant overhanging graft is trimmed with the knife included in the kit. (Fig. 11)

  

Figures 11,12,13   The redundant portion of graft is trimmed.  (Fig. 11)  The graft is introduced (Fig. 12) and gently tamped into place.  Gently contour the graft as needed with a scalpel. (Fig. 13)

The delivery device is then reintroduced to the lesion with the graft now facing distally toward the lesion. It is helpful to advance the graft a few millimeters to help introduce it into the drilled defect. The plunger on the proximal end of the delivery device is then firmly advanced, seating the graft into the defect. (Fig. 12)

It can be gently tamped with a mallet. The graft should sit flush with the articular surface. If there is a small step-off deformity, gently contour the graft with a scalpel. (Fig. 13)

Once the graft has been placed, commence with ORIF of osteotomy if necessary and standard wound closure. (Fig. 14)

Figure 14   The graft is seated in place.  ORIF of the malleolus is then performed with appropriate closure of the surgical site.

According to NEXA, immediately following implantation the scaffold allows blood, marrow and progenitor cells to be transported into the pores. The scaffold provides a porous and mechanically protected environment for healing, tissue in-growth and cellular development. The calcium sulfate dissolves within 6 weeks to 6 months. New tissue forms within the pores. Between 6 months and 12 months, the polymer undergoes resorbtion and is gradually replaced with tissue as well. After 12 months the polymer is predominantly resorbed and the defect will contain new tissue.

Our post-operative treatment protocol consists of non-weight bearing for 2 weeks, followed by active range-of-motion, usually, once the incisions have healed. Partial weight bearing is then employed for 2 weeks, in a fracture boot, with progression to full weight bearing for an additional 2 weeks.

At 6-8 weeks the patient is then enrolled into a formal physical therapy program.

References

1. Canale-ST; Belding-RH Osteochondral lesions of the talus JBJS-Am. 62(1): 97-102, Jan. 1980.
2. Anderson IF, et al: Osteochondral fractures of the dome of the talus JBJS – Am. 71(8):1143-52, Sept. 1989.
3. Brendt, AL, Harty, M. Transchondral fractures (osteochondritis dissecans) of the talus. JBJS. Vol 41-A. 988-1020, 1959.
4. Pettine KA. Morrey BF. Osteochondral fractures of the talus. A long-term follow-up. JBJS – British 69(1):89-92, Jan. 1987.
5. Flick AB. Gould N. Foot & Ankle. Osteochondritis dissecans of the talus (transchondral fractures of the talus): review of the literature and new surgical approach for medial dome lesions. [JC:f3x] 5(4):165-85, Jan-Feb 1985.
6. Kumai T, Takakura Y, Higashiyama I, Tamai S. Arthroscopic drilling for the treatment of osteochondral lesions of the talus. J Bone Joint Surg Am. 81(9):1229-35, Sept, 1999.


 
Address correspondence to: Mark A. Hardy, DPM, FACFAS, Kaiser Permanente Foundation Department of Podiatric Surgery
12301 Snow Road Parma, OH 44130
Email: markhardy@sbcglobal.net

1Senior Resident, Kaiser Permanente/Cleveland Clinic Foundation Residency Program, Cleveland, Ohio.

2Director, Cleveland Clinic/Kaiser Permanente. Foot & Ankle Residency Program. Director, Foot and Ankle Trauma Service. Kaiser Permanente – Ohio Region

© The Foot & Ankle Journal, 2008