Tag Archives: ankle arthrodesis

Ankle Arthrodesis with Silicate-Substituted Calcium Phosphate Bone Graft

by Gregory C. Pomeroy MD1emailsm, Sophia DeBen MD2emailsmpdflrg

The Foot and Ankle Online Journal 6 (1): 2

Bony fusion of joints has been the mainstay for management of arthritis in the foot and ankle for many years with cancellous bone from the iliac crest as the graft of choice. Harvest of bone from the iliac crest is a procedure fraught with high cost and morbidity. SiCaP is an osteoconductive calcium phosphate ceramic which elicits osteogenic effects primarily due to the site specific substitution of phosphate ions with silicon (0.8% by weight). The primary aim of this study was to review the fusion success rate and clinical outcomes in 24 patients who underwent tibiotalar arthrodesis with a fibular plate technique and SiCaP bone graft substitute. Twenty-four patients underwent ankle arthrodeses performed by one surgeon (GCP) from March 2008 to March 2009. All had the same operative technique using a transfibular ankle arthrodesis with multiple screw fixation and a fibular onlay strut graft. In this series using SiCaP, we were able to obtain a 91% fusion rate and an 86% satisfaction rate with an average improvement of 47 points using the AOFAS score. In conclusion we have demonstrated that SiCaP bone graft substitute to be a viable alternative for fusion in the foot and ankle.

Key words: Ankle arthrodesis, bone graft substitute, silicated calcium phosphate

Accepted: December, 2012
Published: January, 2013

ISSN 1941-6806
doi: 10.3827/faoj.2013.0601.002


Address correspondence to:1Gregory C. Pomeroy MD, New England Foot and Ankle Specialists, 195 Fore River Parkway, Portland, ME, United States 04102 E-Mail: gpome40@hotmail.com

2 Naval Hospital Camp Lejeune, 100 Brewster Blvd. Camp Lejeune, North Carolina, 28547 E-Mail: sophiadeben@hotmail.com


Bony fusion of joints has been the mainstay for management of arthritis in the foot and ankle for many years. Until recently, fusion was the only reliable means of surgically treating patients with advanced arthrosis of the ankle joint, as it provided predictable stability and relief of pain.

While the resurgence of popularity in total ankle replacement is currently exhibiting promising results, ankle fusion still remains the gold standard for the management of ankle arthritis.

Previous studies have focused on evaluating different constructs and implants in order to improve fusion rates. The current fusion success rates for ankle arthrodesis are reported to be approximately 90%.[1,2]

ActifuseAFusFig1AB

Figure 1 Silicated calcium phosphate (gray) integration with the surrounding bone matrix (red). Evidence of graft incorporation at 6 months [Magnification x 520] (a). Evidence of early bone formation at 2 months. [Magnification x 510] (b).

Reprinted from Spine Journal: Official Journal of the
North American Spine Society , 7/3, Wheeler, D, Jenis, L, Kovach, M, Marini, J, Turner, S, Efficacy of silicated calcium phosphate graft in posterolateral lumbar fusion in sheep, 308-317, Copyright 2007. (With permission from Elsevier).

This significant improvement from the previously cited rates of 40% and 60% for nonunion and complications, respectively is mostly due to the use of rigid internal fixation.[3] Several different constructs have demonstrated valid, reproducible results including the application of external fixation, crossed screws, fixed-angled plates and screws, fibular strut grafting and intramedullary fixation, which sacrifices the subtalar joint.[4] The majority of the data reported used cancellous bone from the iliac crest as the graft of choice.

Recent advances in the field of bone physiology have succeeded in identifying the various factors needed for new bone formation. Demineralized bone matrices, calcium-based substrates, marrow-derived stem cells and bone morphogenic proteins have all been identified as contributing to neo-osteogenesis.[5] These commercially available agents have been studied in the spine, in fractures of the upper and lower extremities, and in foot and ankle procedures in order to find a suitable replacement for iliac crest bone graft (ICBG). ICBG possesses osteogenic, osteoinductive, and osteoconductive properties, and is effective in achieving a solid fusion at multiple anatomic sites. However, harvest of bone from the iliac crest is a procedure fraught with high cost and morbidity.[6,7]

In an attempt to control this expense and reduce complications to the patient, these alternative “off-the-shelf” bone graft substitutes are continually being investigated for their clinical utility as replacement bone graft materials.[8]

One such bone graft alternative, SiCaP (Actifuse, Apatech), has been initially tested with success in lumbar posterolateral fusion in sheep. Pre-clinical data from the posterolateral lumbar fusion sites in sheep treated with Actifuse reveal robust graft integration at 2 and 6 months.[9] (Fig. 1) SiCaP is an osteoconductive calcium phosphate ceramic which and elicits osteogenic effects primarily due to the site specific substitution of phosphate ions with silicon (0.8% by weight). The addition of silicon in the form SiO44- has been reported to upregulate osteoblast proliferation and differentiation, promote osteoinductive gene expression and increase Type I collagen synthesis.[10,11] More importantly, clinical data on lumbar fusion with silicate-substituted calcium phosphate (SiCaP) v. ICBG in adults reveals equal or greater healing rates.[12] The osteogenic, osteoconductive, and osteoinductive effect of this ceramic has characteristics suggesting that it may be a reasonable alternative to ICBG.

The primary aim of this study was to review the fusion success rate and clinical outcomes in 24 patients who underwent tibiotalar arthrodesis with a fibular plate technique and SiCaP bone graft substitute.

Methods

Twenty-four patients underwent ankle arthrodeses performed by one surgeon (GCP) from March 2008 to March 2009. All had the same operative technique using a transfibular ankle arthrodesis with multiple screw fixation and a fibular onlay strut graft. The etiology of their arthritis was traumatic in fourteen patients, previous talar OCD in two patients, and the remaining patients were of insidious onset. There were six with varus malalignment and six with valgus malalignment, defined as tilt of the talus on standing anterior posterior view of the ankle greater than 3 degrees. Sixteen patients used either a custom AFO or Arizona brace prior to proceeding with ankle fusion.

ActifuseAFusFig2

Figure 2 Actifuse granules.

Interval follow-up visits were scheduled at five and eight weeks, three months, and six months. Postoperative standing anteroposterior and lateral radiographs were routinely obtained at two week and eight week visits. Evaluation to determine if the ankle joint was indeed fused was done so radiographically. Time to osseous union was determined by clinical stability and radiographic evidence of bridging bony trabeculae across the tibiotalar space. Once bony healing had occurred, patients were advanced to full weightbearing without protection.

The American Orthopaedic Foot and Ankle Society’s (AOFAS) ankle-hindfoot rating scale was applied retrospectively to obtain a preoperative and postoperative score.[13]

Statistical comparisons were made using Wilcoxon’s signed-rank test to compare pre- and postoperative values within each individual variable studied. The paired t-test was used to assess the statistical significance of the patients’ preoperative and postoperative AOFAS ankle-hindfoot scale scores. Comparisons were considered statistically significant if p<0.05.

Operative Technique

The patients were positioned supine with a thigh tourniquet and a bolster under the buttock to allow for exposure of the lateral aspect of the operative ankle.

An 8 cm anterolateral incision was used to expose the distal fibula and syndesmosis. Care was taken to preserve the posterior soft-tissue envelope of the distal fibula. The fibula was transected 6 cm proximal to its distal tip and a 1 cm segment was removed. The anterior syndesmosis was sharply debrided, allowing the distal fibula to hinge posteriorly. A small bump was placed under the distal tibia to allow the body of the talus to be translated posteriorly onto the tibia. If there was an anterior tibial spur, it was removed with a curved osteotome. The tibiotalar joint was then distracted with lamina spreaders and denuded of articular cartilage. The tibiotalar joint and lateral tibia and talus were denuded of cartilage with osteotomes and curettes.

A separate medial incision of 4 cm was made just medial to the tibialis anterior tendon as it crossed the ankle joint. The tendon and neurovascular bundle were retracted laterally. The medial gutter was exposed, anterior osteophytes removed, and the medial aspect of the tibiotalar joint was denuded of residual articular cartilage.

Multiple subchondral perforations into the tibial plafond, talus, and syndesmosis, were created with a 2 mm drill bit to improve vascular ingrowth. If the bony deformity prevented proper alignment, an osteotome was used to plane the joint. The distal fibula was split in half in the sagittal plane. The medial half of the distal fibula was excised. The transverse osteotomy was performed first to avoid breaking the fibular strut while denuding the syndesmosis. If at this time the ankle could not be reduced to a neutral position in the sagittal plane, a percutaneous Achilles tendon lengthening was conducted.

Depending on the size of the patient, the contents of a 1.5 or 2.5 cc vial of SiCaP granules. (Fig. 2) were packed into both the tibiotalar and distal tibiofibular joints via both incisions.

ActifuseAFusFig3

Figure 3 Pre-operative anterior posterior and lateral images before ankle arthrodesis.

The tibiotalar joint was then manually reduced and maintained in neutral while three partially threaded 6.5 mm screws were placed in compression after recessing the screw heads were recessed with a burr.

Anteroposterior and lateral views of the ankle and a Harris view of the subtalar joint were obtained to confirm adequate reduction of the tibiotalar joint, proper ankle alignment, and absence of penetration of the subtalar joint with the fixation devices. Once acceptable fixation was achieved, the lateral half of the distal fibula was placed across the ankle joint with the cancellous surface against the prepared tibia and talus. The fibular strut was then maintained reduced with a large pelvic reduction clamp while it was secured in compression with a 4.5 mm screw proximally into the tibia and a 6.5 mm screw distally into the talus. If any further procedures were completed, they were initiated at this time. Otherwise, the wounds were gently irrigated and closed with interrupted 3-0 monocryl suture and the skin was approximated with staples. The ankle was then immobilized in an accommodative splint.

ActifuseAFusFig4

Figure 4 Post-operative anterior posterior and lateral images after successful ankle arthrodesis.

Post Operative Course

Postoperative instructions included strict non-weight bearing and elevation for eight weeks. After the postoperative splint and staples were removed at two weeks, patients were placed in a fiberglass cast for a total of eight weeks of immobilization. Full weight-bearing in a shoe was initiated at eight weeks, unless there was clinical or radiographic evidence of delayed union. Patients not radiographically healed by eight weeks were allowed to weight bear as tolerated in a walking cast boot.

Results

Radiographs for all patients were available at three months to evaluate the fusion site. Twenty-two of the 24 patients had radiographic evidence of union (91.6%). The average time to union was 71.4 days (range of 60-180 days).

Two patients were lost to follow up for their one year AOFAS score, however, both patients for whom complete records were not available did have postoperative radiographs verifying bony healing. Of the 22 patients with completed postoperative data, the average age was 56 years (24-79). The average follow-up was 22 months (14-26 months). The 22 patients who were evaluated with an AOFAS score had an average improvement from 35 to 82 points (p<0.002).

One patient reported to continuing smoking during their recovery. Five patients of the study group were being treated for diabetes mellitus. Four patients received perioperative immunosuppressants, one due to their solid organ transplant, two for their rheumatoid disease and one for myelodysplasia. Four patients were chronically on narcotic analgesics immediately prior to surgery. One patient was a revision ankle fusion who underwent a concomitant subtalar fusion. Two patients had first metatarsal dorsiflexion osteotomies with peroneus longus to brevis transfers for forefoot driven hindfoot varus and one patient had a concomitant joint sparing flatfoot reconstruction.

One patient who did not heal his arthrodesis was on chronic immunosuppressants and was receiving supplementary dialysis at home for a failing renal transplant. A second patient had the fusion site collapse into valgus and required an Arizona brace for ambulation in the community. He had no significant medical comorbidities, but did have a rigid subtalar joint upon examination preoperatively. On review of his radiographs, his medial gutter was lagging in mineralization at two months when he was released to full, unprotected weight bearing.

Four patients had a superficial wound dehiscence that resolved with wound care and limited oral antibiotics. Nineteen of the 22 patients available for follow-up AOFAS scores at one year were very satisfied (86%). Of the three patients with persistent pain and disability, all three were on chronic narcotics preoperatively. One of these was the nonunion which had collapsed into valgus.

Concomitant procedures were completed in five patients. One patient who was undergoing a revision ankle fusion also had a subtalar fusion with screws at the same time. SiCaP granules were used as the graft at that level as well. One patient had hardware removed that was previously placed to treat her ankle fracture. One patient had a flat foot reconstruction as previously described by Pomeroy et al. and two had concomitant cavovarus reconstructions.[14] Interestingly, the two patients with the lowest postoperative AOFAS scores were these two patients.

At six months, two patients presented with persistent pain at the lateral screws and about the fibula. They both underwent removal of the distal fibula with screw removal from the lateral side only and resolution of their symptoms.

Discussion

Currently, there is estimated to be one million bone graft procedures performed annually in the United States and Europe.[15] In these procedures, harvesting of autogenous bone graft is predominantly from the iliac crest but also includes local sources such as the tibia and calcaneus, which carry significant morbidity and cost. Identification of a substitute synthetic material with similar structural characteristics as native bone material remains elusive.

Demineralized bone matrix (DBM) and bone mineral proteins (BMP) are known to be osteoinductive. They are limited, however, by the variability in their production, carrier, and purity.[8] They are not osteoconductive unless loaded onto a carrier with a three-dimensional calcium based scaffold.

While both calcium phosphate and calcium sulfate preparations are osteoconductive, the carbonated hydroxyapatite that forms on the surface of the biomaterial has been shown to be osteoinductive.[16] In particular, it is able to recruit stem cells and promote growth factors. CaP biomaterials have a surface geometry that when placed in a living bone microenvironment allows for adsorption of endogenous BMPs, but this is also dependent on the pore size of the material.[17]

Silicated calcium phosphate has several unique features differentiating it from other bone graft substitutes. The site-specific silicate substitution gives SiCaP osteogenic properties as well. In-vitro data collected from tissue-culture studies with osteoblast-like cells reveals that silicon ions may leech out of the graft material into the surrounding bony microenvironment.[18] Silicon ions have been reported to increase osteoblast production of Type I collagen[18] as well as to upregulate production of amelogenin and enamelin that are precursors to osteogenesis in teeth.[19] It has also been reported that silicon in the extracellular matrix of bone can lead to upregulation of osteoblast proliferation and differentiation.[20,21] By affecting control over bone scaffold physio-chemistry and microstructure, it is proposed that this bone graft substitute can produce effects similar to autogenously transplanted material.

This notion is supported by the increased activity of human SaOS-2 cells in culture in the presence of silicate substituted hydroxyapatite.[11] It also has a profoundly greater osteoconductive effect compared to biomaterials that do not contain silicon. In pre-clinical studies using the distal femurs of rabbits that had been implanted with cylinders impregnated with silicate-substituted hydroxyapatite, there was a significant difference in the location and amount of bone formed. Silicate-substituted hydroxyapatite cylinders had significantly increased new bone formation into the slots of the device when compared to non-substituted hydroxyapatite.[22]

In vivo data on ovine and human bone supports the early data that the combination of hydroxyapatite and silicon in this material generates an osteogenic effect equal or greater than autogenous bone graft.[23] In one pre-clinical study, posterolateral lumbar fusion was accomplished in an ovine model comparing autograft to silicon-substituted hydroxyapatite. Histomorphometric analysis at 6 months revealed that the fusion mass was greater than and the bony bridging equivalent to the autogenously grafted levels.[9] In a clinical one-year study, the data on transforaminal interbody fusion using silicate-substituted hydroxyapatite revealed a 96% fusion rate as confirmed by CT scan.[12]

Other data comparing rhBMP-2, while another class altogether, is the only other shelf product that has fusions equal to ICBG but in the 90% range. A cost analysis of this material compared to ICBG was completed on 102 patients receiving lumbar fusion. In this prospective randomized clinical trial, patients receiving rhBMP-2 had similar clinical outcome scores, fewer complications, and experienced an average cost savings of $2,319 per patient.[24]

In this series using SiCaP, we were able to obtain a 91% fusion rate and an 86% satisfaction rate with an average improvement of 47 points using the AOFAS score. Previous literature using this technique and autogenous iliac crest cited a 96% fusion rate and an average improvement of 36 points on the AOFAS score.[25]

In conclusion we have demonstrated that SiCaP bone graft substitute to be a viable alternative for fusion in the foot and ankle. While obtaining successful arthrodesis across any joint is a multifactorial process, this product has shown to provide outcomes similar to iliac crest bone graft and should be considered for further clinical investigation.

References

1.  Kitaoka HB.  Arthrodesis of the ankle: technique, complications, and salvage treatment.  Instr Course Lect  1999 48: 255-261. [PubMed]
2.  Mann RA, Rongstad KM. Arthrodesis of the ankle: a critical analysis.  Foot Ankle Int 1998 19: 3-9. [PubMed]
3.  Raikin SM. Arthrodesis of the ankle: arthroscopic, mini-open, and open techniques.   Foot Ankle Clin 2003 8: 347-359.
4.  Chen YJ, Huong TJ,  Shih HN, Hsu KY, Hsu RW.  Ankle arthrodesis with cross screw fixation.  Good results in 36/40 cases followed 3-7 years.  Acta Orthop Scand 1996 67: 473-478. [PubMed]
5.  Reddi AH. Morphogenesis and tissue engineering of bone and cartilage: inductive signals, stem cells and biomimetic biomaterials.  Tissue Eng 2000 6: 351-359. [PubMed]
6.  Arrington E, Smith W, Chambers H, Bucknell AL, Davino NA. Complications of iliac crest bone graft harvesting. Clin Orthop 1996  329: 300-309. [PubMed]
7.  Banwart J, Asher M, Hassanein R. Iliac crest bone graft harvest donor site morbidity. A statistical evaluation. Spine 1995 20: 1055-1060. [PubMed]
8.  Hing K. Bone repair in the twenty-first century: biology, chemistry or engineering? Interdisciplinary Research Centre in Biomedical Materials, Queen Mary, University of London, London E1 4NS, UK, Published online 24 September 2004. [PubMed]
9.  Wheeler DL, Jenis LG, Kovach ME, Marini J, Turner AS. Efficacy of silicated calcium phosphategraft in posterolateral lumbar fusion in sheep. Spine J 2007 7: 308-317. [PubMed]
10.  Gibson I, Hing K, Revell P, et al.: Enhanced in vivo response to silicate-substituted hydroxyapatite. Key Eng Mater 2002 20: 203–206.  
11.  Muller W, Boreiko A, Wang X, Krasko A, Geurtsen W, Custódio MR, Winkler T, Lukić-Bilela L, Link T, Schröder HC. Morphogenetic analysis of silica and biosilica on the expression of genes controlling biomineralization using SaOS-2cells. Calcif Tissue Int 2007 81: 382-393. [PubMed]
12. Aubin M, Drew J, Eskander M, Lange J,  Clinical and radiological fusion rates following TLIF with silicate substituted calcium-phosphate bone graft substitute for the surgical treatment of degenerative lumbar spine disease. Spine: Affiliated Society Meeting Abstracts. (Supplement 2010 Paper Abstracts: 2009 CSRS Meeting Abstracts and Posters) 2010:177.  
13.  Kitaoka H, Alexander I, Adelaar R,  Clinical rating systems for the ankle-hindfoot, midfoot, hallux and lesser toes. Foot Ankle Intl 1994 15: 349-353. [PubMed]
14.  Mosier-LaClair S, Pomeroy G, Manoli A 2nd. Operative treatment of the difficult stage 2 adult acquired flatfoot deformity.  Foot and Ankle Clinics 2001 6: 95-119. [PubMed]
15.  Beattie JH, Avenell A. Trace element nutrition and bone metabolism.  Nutr Res Rev 1992 5: 167-188. [PubMed]
16.  Yuan H, Kurashina K, de Bruikn JD, Li Y, de Groot K, Zhang X. A preliminary study on osteoinduction of two kinds of calcium phosphate ceramics.  Biomaterials 1999 20: 1799-1806. [PubMed]
17.  Lee KY, Park M, Kim HM, Lim YJ, Chun HJ, Kim H, Moon SH. Ceramic bioactivity: progress, challenges and perspectives. Biomed Mater 2006 1: 31-37. [PubMed]
18.  Guth K, Buckland T, Hing KA.  Silicon dissolution from mircoporous silicon substituted hydroxyapatite and its effect on osteoblast behavior. Key Engineering Materials 2006 117: 309-311.
19.  Muller W, Boreiko A, Wang X, Krasko A, Geurtsen W, Custódio MR, Winkler T, Lukić-Bilela L, Link T, Schröder HC.  Morphogenic activity of silica and bio-silica on the expression of genes controlling biomineralization using SaOS-2 Cells.  Calcif Tissue Int 2007 81: 382-393. [PubMed]
20.  Patel N, Brooks RA, Clarke MT, Lee PM, Rushton N, Gibson IR, Best SM, Bonfield W. In vivo assessment of hydroxyapatite and silicate-substituted hydroxyapatite granules using an ovine defect model. J Mater Sci Mater Med 2005 16: 429-440. [PubMed]
21.  Patel N, Best SM, Bonfield W, Gibson IR, Hing KA, Damien E, Revell PA. A comparative study on the in vivo behaviour of hydroxyapatite and silicon substituted hydroxyapatite granules. J Mater Sci Mater Med 2002 13: 1199-1206. [PubMed]
22.  Hing KA, Revell PA, Smith N, Buckland T. Effect of silicon level on rate, quality and progression of bone healing within silicate-substituted porous hydroxyapatite scaffolds. Biomaterials 2006 27: 5014-5026. [PubMed]
23.  Gibson IR, Hing KA, Revell PA, Santos JD, Best SM, Bonfield W. Enhanced in vivo response to silicate-substituted hydroxyapatite.  Key Engineering Materials 2002 218: 203-206.  
24.  Carreon L, Glassman S, Djurasovic M, Campbell M, Puno R, Johnson J, Dimar J. RhBMP-2 Versus iliac crest bone graft for lumbar spine fusion in patients over 60 years of age: a cost –utility study. Spine 2009  34: 238-243. [PubMed]
25.  Colman A, Pomeroy G. Transfibular ankle arthrodesis with rigid internal fixation: an assessment of outcome. FAI  2007 28: 303- 307. [PubMed]


© The Foot and Ankle Online Journal, 2013

Neuropathic Ankle Arthrodesis with Intramedullary Nail Fixation

by Brent Bernstein, DPM FACFAS1, Zachary Ritter, DPM2, Robert Diamond, DPM FACFAS3

The Foot and Ankle Online Journal 5 (7): 1

Tibiotalocalcaneal/Tibiocalcaneal arthrodesis with intramedullary nail fixation is a useful and stable means through which to address complex rearfoot deformities. In this manuscript, we have critically analyzed the modalities and surgical outcomes within existing literature comparing each to our institutional results and have found a critical void in information. In tracking and addressing variables such as smoking cessation, glucose control, weight management, vascular stability, extremity ulcerations and postoperative pedorthics we have observed improved operative outcomes and fusion rates. In reviewing the literature, we have found bone union rates of 79.6%, non-union rates of 7.6%, fracture rates of 1.4% and amputation rates of 4.7%. Those results were then compared to our rates of 88.88%, 11.12%, 0% and 0% respectively. Yet, while our institution noted improved results, a meaningful meta-analysis was difficult to achieve considering that most literature failed to make note of the aforementioned variables. Accordingly, we offer that a strict preoperative regimen of glycemic control, vascular patency, weight management and smoking cessation, in conjunction with strict postoperative non-weight bearing and aggressive wound management will improve overall results. Furthermore, it is our suggestion that future research address these topics.

Key Words: Neuropathic Ankle Arthrodesis, Intramedullary Nail Fixation, Charcot, Ankle Fusion, Diabetes

Accepted: June, 2012

Published: July, 2012

ISSN 1941-6806
doi: 10.3827/faoj.2012.0507.0001


Charcot neuropathic osteoarthropathy is a destructive disease of neurologic origin that contributes to both bone and joint abnormalities.

While its pathogenesis is not completely understood, the Charcot process is thought to be a product of neurovascular and neurotraumatic etiologies with effects reaching far beyond the diabetic community.

In examining the Charcot limb it is important to understand that this deformity will typically present in three anatomic planes–the sagittal, transverse and frontal. The effects of that triplanar deformity are most notable in the Charcot ankle, with severe valgus or varus fixed deformities or occasionally “flail” ankles with the foot being stabilized on the lower extremity by soft tissue alone [1,2].

Figure 1 3-D computed tomography reconstruction of patient 1.

Often, patients also experience postural changes and a grossly unstable bony architecture presenting the need for aggressive surgical correction [3-6].  With that, one mainstay of therapy remains rearfoot fusion with intramedullary nail fixation [2,7]. It is expected that anywhere from 0.1 to 5% of all diabetic patients will develop neuropathic osteoarthropathy during the course of their disease; these odds are increased substantially in patients with end-stage neuropathy [3,4,8-10].  Moreover, diabetic patients with ulcerations are significantly more likely to undergo extremity amputation. With these odds, it is extremely important for the foot and ankle specialist to judiciously approach the Charcot joint.

Our study evaluates the results of bone fusion rates and outcomes with tibiotalocalcaneal/tibiocalcaneal arthrodesis. In order to accomplish this, we have explored our institutions outcomes alongside those of existing literature to demonstrate commonalities and techniques for successful treatment and/or interventional modalities. To this end, it is our hypothesis that meticulous preoperative planning, intraoperative techniques, and post-operative care significantly affect the success of the fusion rates.

Figure 2 Post-operative radiograph of patient 1.

Methods and Materials

An extensive literature review of selected electronic databases including PubMed, the Cochrane Database and OVID was conducted for articles using the key words “Charcot ankle”, “intramedullary nail”, and varied combinations of each. No specific time parameters were set; accordingly, articles were reviewed from inception to present. Studies were excluded if they were not available in English, did not address the use of intramedullary nail fixation for the diabetic Charcot ankle deformity or did not note postoperative weight-bearing, obesity, wound care or union type.  With that, only thirteen articles were found to meet our inclusion criteria. (It should be noted that our original inclusion criteria included monitoring of blood glucose levels, nutritional status, vascular stability and nicotine use, however literature that followed these variables was extremely limited).

Secondarily, a review of our senior authors (B.B.) patient database was conducted.  Nine consecutive patients who had undergone tibiotalocalcaneal/tibiocalcaneal arthrodesis using an intramedullary nail between January of 2005 and 2009 were selected for review. Perioperative data was obtained from our institutions electronic medical record system and wound care facility records.

Figure 3 Pre-reduction radiograph of patient 2.

Of the nine patients followed within our institution, eight were diagnosed with a Sanders IV Charcot deformity, seven had a medical history significant for diabetes mellitus, and seven weighed over 102kg. The average patient age was fifty-five years with eight males and one female.  All diabetics demonstrated a hemoglobin A1c of less than 7.5%. Stable lower extremity arterial studies as per our institutions vascular surgeons were noted along with dopplerable pedal pulses.

All patients had also transitioned from the active phase of neuroarthropathy to the chronic phase as demonstrated by cutaneous infrared thermistor readings being equalized to within 2 degree Celsius of the contralateral unaffected limb [11,12].

Figure 4 Post-operative radiograph of patient 2.

Patients who demonstrated active “hot” joints were managed pre-operatively with protected weightbearing in total contact casts with adjunctive therapy of oral or parenteral bisphosphonates or miacalcin nasal spray and/or non-invasive bone stimulation therapy until temperature readings equalized and edema had resolved.

Patients from our senior author’s practice were refused surgical intervention if at the time of surgery they 1- had an open wound, 2-had not accomplished pre-operative glycemic control, 3- had not undergone tobacco cessation, 4-had not attempted weight management or 5- did not have adequate vascular runoff/perfusion as determined by our facilities vascular testing (ABI/PVR) (Table 1).

Table 1 Preoperative requirements

Post-operatively, our patients were kept strict non-weight bearing until clinical stability was noted. At that time they were transitioned into a total contact cast and finally, as consolidation completed, to accommodative shoe gear or custom-fabricated ankle-foot orthosis. All patients were followed postoperatively at our facility’s wound care center for weekly appointments until that time when independence and function had been restored. Additionally, all post operative wounds were treated at that same facility by certified wound care specialists until the time of their resolution.

Surgical Technique

A hockey stick type incision was made over the fibula and curved distally to the level of the sinus tarsi at the base of the fourth metatarsal. The fibula was then exposed and the distal aspect of the fibula was resected. Typically, the fibula was morselized to be incorporated as bone graft material to fill osseous deficits. An accessory medial ankle incision allowed adequate debridement of devitalized talus and preparation of the joint surfaces. Standard technique included a talectomy and insertion of a wedged portion of bone (autograft from the talectomy or fresh frozen femur) to allow the tibia to seat at 90 degrees to the weightbearing surface in contact with the posterior facet of the calcaneus.  All opposing surfaces of tibia, calcaneus and navicular were denuded of cartilage and multiple subchondral drill holes were created through their articulating surfaces. Additionally, the anterior tibia and bone graft wedge were similarly fenestrated to facilitate bony fusion.

All deficits were back-filled with the morselized fibula graft. Frequently, the Achilles tendon was released at this time. The foot was then assessed for proper positioning and placement of the IM nail. At that time, the guidewire for the nail was placed within the anterior aspect of the plantar heel through the talus–centered into the medullary canal of the tibia. That was then confirmed by intraoperative C-arm guidance in AP, and lateral positions. The bone was drilled, reamed, and placement of the nail was performed utilizing the systems jig. Depending on the system utilized, compression was achieved across the arthrodesis site either externally with tightening of the jig/”top hat” against the external heel pad or plantar calcaneus, via manual compression of the heel, internally through the compression bolts, or externally via external fixation bolts incorporated on the jig. Following insertion of compression screws to fix the nail to the osseous structures, the jig was removed and the IM nail was visualized by C-arm for positioning. Subcutaneous structures were closed with 3.0 vicryl and the skin with staples (Table 2). The incisions were covered with Xeroform™ and a Robert Jones compression dressing. Postoperatively the patient was placed on bedrest with ice, elevation and subcutaneous low molecular weight heparin (Table 3).

Table 2 Intraoperative Techniques

Table 3 Postoperative Management

Results

Osseous fusion, defined as trabecular bridging at the fusion site with disappearance of appositional gapping, was noted in 88.8% of all patients within our institution. Categorically, fusion was seen in 85.7% of diabetics, 87.5% of Charcot limbs, 85.7% of those weighing over 102kg and 88.8% of those placed in a postoperative TCC.

Figure 5 Pre-reduction clinical image of patient 3.

Comparatively, literature has demonstrated fusion rates of 73%, 70.4%, 92.4% and 46.2% respectively [2-4,7,8,13-20].

Moreover, our institution demonstrated significantly fewer post-operative complications when compared to published literature 11.12% non-unions, no amputations and no osseous fractures. Somewhat skewed, however, is the above average number of post-operative wounds encountered within our institution 44.4% as opposed to 18% in literature. Although that statistic could certainly be secondary to the extent of deformity or aggressive tracking, it is hard to draw any correlations due to the lack of detailed information with those articles reviewed.

Figure 6 Post-reduction clinical image of patient 3.

Discussion

In recent years indications for tibiotalocalcaneal/tibiocalcaneal fusion have expanded, likely because of improved fixation methods [2]. Intramedullary fixation is biomechanically more rigid than crossed lag screws when examining flexion and torsional forces [13]. Accordingly, retrograde intramedullary nailing is a good option for complex tibiotalocalcaneal/tibiocalcaneal fusions, especially in patients with Charcot arthropathy [21-24]. The construct does allow for weightbearing six to eight weeks after surgery while demonstrating fusion rates that approach ninety percent.

As with any surgical patient, a thorough preoperative assessment should be performed. It is essential to consider the entire patient and not simply the deformity. Therefore, a complete physical examination and adequate overall health evaluation is essential to choose an appropriate surgical candidate.

In this small retrospective analysis, we propose that the following reasons could account for our improved fusion rate. First, critical preoperative planning, including thorough evaluation of the osseous deformity with a 3-D 64 slice CT scan and long-leg axial radiographs. Second, all patients were followed-up at our institutions wound management center to facilitate aggressive management of pre-operative and post-operative wound complications. Third, evaluation of the patient’s vascular status with non-invasive arterial testing such as toe pressures, ankle/brachial indices and arterial Doppler examination during preoperative evaluation proved to be invaluable when determining inclusion criteria. Fourth, patients were offered enrollment in weight loss and smoking cessation programs preoperatively, deferring surgery until this occurred. Fifth, physical therapy training preoperatively and strict non-weight-bearing postoperatively was maintained for eight weeks after which total contact casting and finally bracing was applied. Sixth, nutritional factors were medically evaluated and patients were under firm metabolic control.

Overall, in reviewing the data offered in our literature review and that of institutional review, it is difficult to do a successful and meaningful meta-analysis given the overall lack of detailed patient information and differentiation. Most publications made little mention of preoperative variables that our authors found exceedingly important to track ABI/PVR, weight management, extent of diabetic control, preoperative wound/deformity, tobacco use, etc. In that void, as previously noted, the authors of this study were required to exclude a majority of papers found. Within the grouping of useful studies (Table 1), patient results were taken individually for correlation accounting for the varying cohort numbers (n=). Meaning, each variable along the x-axis consists of a compilation of data collected from different publications. Accordingly, it is an imperative that future studies more closely follow and account for those variables.

This study demonstrates that, while great strides are being made in the world of reconstructive surgery for neuropathic osteoarthropathy, there remains a void in critical information. Information that will not only lead to better standards in surgical management, but also to a more detailed understanding of the Charcot limb and improved techniques in limb salvage.

References

1. Kile TA, Donnelly RE, Gehrke JC, Werner ME, Johnson KA. Tibiotalocalcaneal arthrodesis with an intramedullary device. Foot Ankle Int 1994 15: 669-673. [PubMed]
2. Stone NC, Daniels RT. Midfoot and hindfoot arthrodesis in diabetic Charcot arthropathy. Can J Surg 2000 43: 449-455. [PubMed]
3. Papa J, Myerson M, Girard P. Salvage with arthrodesis, in intractable diabetic neuropathic arthropathy of the foot and ankle. JBJS 1993 75: 1056-1066. [PubMed]
4. Pinzur MS, Sage R, Stuck R, Kaminsky S, Zmuda A. A treatment algorithm for neuropathic midfoot deformity. Foot Ankle Int 1993 14:189-197. [PubMed]
5. Simon SR, Tejwani SG, Wilson DL, Santner TJ, Denniston NL. Arthrodesis as an early alternative to nonoperative management of Charcot arthropathy of the diabetic foot. JBJS 2000 82A: 939-950. [PubMed]
6. Wagner FWW. The Diabetic Foot and Amputations of the Foot. Surgery of the Foot, 5th Ed. Mann, PR (ed.), St. Louis, CV Mosby, 421-455, 1986.
7. Pinzur MS, Noonan T. Ankle arthrodesis with retrograde femoral nail for Charcot ankle arthropathy. Foot Ankle Int 2005 26: 545-549. [PubMed]
8. Caravaggi C, Cimmino M, Caruso S, Dalla Noce S. Intramedullary compressive nail fixation for the treatment of severe Charcot deformity of the ankle and rear foot. J Foot Ankle Surg 2006 45: 20-24. [PubMed]
9. Schon LC, Marks RM. The management of neuropathic fracture-dislocation in the diabetic patient. Orthop Clin North Am 2002 26:375-393. [PubMed]
10. Sanders LJ, Mrdjenovich D. Anatomical pattern of bone and joint destruction in neuropathic diabetes. Diabetes 1991 40 (suppl 1): 529A.
11. Eichenholtz SN. Charcot Joint. Charles Thomas, Springfield, IL, 1996.
12. Sanders LJ, Frykberg RG. Diabetic Neuropathic Osteoarthropathy: The Charcot Foot. The High Risk Foot in Diabetes Mellitus. Churchill Livingstone, New York, 1991.
13. Pinzur MS, Kelikian A. Charcot ankle fusion with a retrograde locked intramedullary nail. Foot Ankle Int 1997 18: 699-704. [PubMed]
14. Dalla Paola L, Volpe A, Varotto D. Use of retrograde nail for ankle arthrodesis in Charcot neuroarthropathy: A limb salvage procedure. Foot Ankle Int 2007 28: 967-970. [PubMed]
15. Mendocino R, Catanzariti AR, Saltrick KR. Tibiotalocalcaneal arthrodesis with retrograde intramedullary nailing. J Foot Ankle Surg 2004 43: 82-86. [PubMed]
16. Moore TJ, Prince R, Pochatko D, Smith J, Fleming S. Retrograde intramedullary nailing for ankle arthrodesis. Foot Ankle Int 1995 16: 433-436. [PubMed]
17. Stuart MJ, Morrey BF. Arthrodesis of the diabetic neuropathic ankle joint. Clin Orthop 1990 253: 209-211. [PubMed]
18. Shibata T, Tada K, Kagawa, Chohzo H. The results of ankle arthrodesis of the ankle for leprotic neuroarthropathy. JBJS 1990 72A: 749-756. [PubMed]
19. Stone KH, Helal B. A method of ankle stabilization. Clin Orthop 1991 268:102-106. [PubMed]
20. Pelton K, Hofer JK, Thordarson DB. Tibiotalocalcaneal arthrodesis using a dynamically locked retrograde intramedullary nail. Foot Ankle Int 2006 27: 759-763. [PubMed]
21. Baravarian B, VanGils CC: Arthrodesis of the Charcot foot and ankle. Clin Pod Med Surg 2004 21: 271-289. [PubMed]
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Address correspondence to: Brent Bernstein, DPM, 303 W. Broad St, Bethlehem, PA 18018

1Director of the Charcot Reconstructive Foot Program and Attending Surgeon, Podiatric Surgical Residency, St. Luke’s University Health Network, Bethlehem, PA
2Chief Resident, Podiatric Surgical Residency, St. Luke’s University Health Network, Bethlehem, PA
3Chief of Podiatric Surgery and Residency Director, Podiatric Surgical Residency, St. Luke’s University Health Network, Bethlehem, PA

© The Foot and Ankle Online Journal, 2012

Ankle arthrodesis as a salvage procedure: A case of secondary ankle arthritis using Charnley’s compression device

by Narayana B.S. Gowda, D Ortho, DNB Ortho, MNAMS, Mohan J. Kumar, MS Ortho

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

Ankle arthrodesis is commonly considered to be the standard operative treatment for end stage ankle arthritis. The purpose of this study was to perform a clinical and radiographic review to determine functional outcome for a group of patients in whom an ankle arthrodesis had been performed using Charnley’s compression device. A functional assessment of fifteen patients after ankle arthrodesis for post traumatic arthritis was carried out by means of an extensive clinical evaluation after an average follow up of 2 years and 8 months.

Key words: Ankle arthrodesis, ankle arthritis, Charnley’s compression device, secondary arthritis ankle.

Accepted: January, 2012
Published: February, 2012

ISSN 1941-6806
doi: 10.3827/faoj.2012.0502.0001


Ankle arthrodesis is considered by many to be the standard operative treatment for end stage ankle arthritis. [1] A patient with ankle arthritis and deformity can experience severe pain and functional disability. Treatment options include the use of walking aids, orthotic devices, intra-articular steroids, open rather than arthroscopic debridement, periarticular osteotomy, and arthroplasty, all of which have provided inconsistent relief. Ankle arthrodesis has been accepted by many as yielding good long term clinical results. [2]

Since 1879, when Albert first described arthrodesis of the ankle [8], more than thirty different techniques have been described. The open technique with compression and internal fixation is still widely used for ankle arthrodesis with major deformity. [9] Ankle arthrodesis is an alternative for cases with intact subtalar joint. [10] This study presents intermediate term follow up functional outcome of patients with ankle arthrodesis performed using Charnley’s compression device.

Materials and methods

We reviewed fifteen patients, 10 males and 5 females, who had undergone ankle arthrodesis between January 2006 to December 2009 at the People’s Education Society (PES) Medical College and Research Center, Kuppam, Andhra Pradesh (AP), India (6 cases of post traumatic AVN talus (Fig. 1), 4 cases malunited bimalleolar fracture, 3 cases of distal tibial plafond fractures, 2 cases of medial malleoli non-union). All the fifteen patients who had secondary ankle arthritis have undergone open ankle fusion with anterolateral approach (Fig. 2) in supine position under tourniquet control and spinal anaesthesia.

Figure 1  Preoperative radiograph right ankle showing arthritic changes secondary to non union talar neck fracture.

Figure 2  Intraoperative photo showing anterolateral approach to ankle.

Compression was achieved using Charnley’s compression device and a calcaneotibial Steinman pin was applied to maintain the alignment and to increase the stability of fixation (Figs. 3 and 4). Suction drain was removed after 48 hours and the patient was made ambulant with non weight on operated site. All the patients were evaluated clinically and radiologically at 6 weeks and tibiocalcaneal Steinman pin was removed and the patients were allowed to bear weight as tolerated. All the fixators were removed after 12 weeks once the arthrodesis site was united radiologically. We had 3 cases of cellulitis of ankle and foot which was treated successfully with antibiotics, and 5 cases of superficial pin tract infection which were healed completely after fixator removal. None of these pin tract infections caused osteomyelitis. The mean age at the time of surgery was 40.52 years (24 – 56 years) and the time interval between the date of fusion and date of follow up examination ranged from 1 year to 5 years and 7 months, the average being 2 years 8 months.

Figure 3  Immediate post operative radiograph showing Charnley’s compression device.

Figure 4  Clinical photo showing Charnley’s compression device.

Clinical Evaluation

The clinical evaluation was based on a personal interview and physical examination. The patients were questioned as to their pain during daily activities such as running or walking on the level ground and going up and down the hills and stairs. A complete orthopaedic examination evaluated stance, gait, limb length discrepancy, circumference, range of motion of the knees, ankles, and subtalar joints; neurovascular status muscle strength and presence or absence of tenderness and swelling. Special attention was directed to the position of the fused ankle and the motion of the subtalar and mid tarsal joints. Any valgus or varus deformities of the heel and the presence of the callosities were also determined. The contralateral extremity was used as a control. Ankle anterior posterior and lateral radiographs were taken to assess the fusion and position of the arthrodesis (Fig. 5).

Figure 5   Two year follow up radiographs shows solid union at the arthrodesis site.

To quantitate the results of the clinical examination the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot scale was used. The main emphasis of this system was on pain and the functional activities. A normal person would score 100 points. Because of lack of ankle motion, the maximum score that the patient with an ankle fusion could have was 92, since they could not earn the 8 points given for the full range of motion.

A score of 80 to 92 was considered an excellent result: 70 to 79, a good result; 60 to 69, a fair result; and score less than 60 was considered a poor result.

Results

All patients studied had a solidly fused ankle and had no complications related to the surgery (Fig 6). They were all improved as a result of ankle fusion and returned to their pre injury activities. Wearing shoes with appropriate heels, all the patients could walk on level ground without support. All the patients stated that they could walk up and down the stairs without much difficulty. Limb length discrepancies were insignificant (0.5 to 1.5 cm) except in one patient who had 2.5 cm secondarily due to distal tibial plafond fracture. The radiographs showed that 6 cases showed some evidence of degenerative changes in the subtalar joints which did not correlate with the symptoms.

Figure 6  Two year follow up clinical photo of right ankle arthrodesis showing very litte difference compared to left normal side.

Scoring the patients with the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot scale, we found that eleven of the 15 had excellent results; two good; and two fair results. All of them could walk with relatively good velocity and with a consistently rhythmic gait.

Discussion

The patients with solid ankle fusion in this study functioned very well during the activities of normal daily living. All of them could walk on the level ground without pain. The fusion had permitted them to return to their former occupations and recreational activities. On this basis all the patients could be classified as having very satisfactory results.

Based on the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot scale, these patients had appreciable limitations when walking barefoot but only mild to moderate limitations when wearing proper footwear. Patients were assessed not only under normal conditions but also under stressful conditions such as walking long distances, climbing up and down the stairs, and running. Six of the 15 could not run. Three had some minor discomfort after walking long distance.

When good surgical technique is used in carefully selected patients, ankle arthrodesis can be a reliable procedure for the relief of functionally disabling ankle arthritis, deformity, and pain. [9] As a fused ankle provides a painless ankle joint with limited functional disability, ankle arthrodesis is still the treatment of choice for most disabling ankle arthritis. [10]

Charnley’s compression devise is still a simple, cost effective and excellent external fixator which can be used easily by every orthopaedic surgeon. After removal of the fixator, there is no indication for additional surgery to remove the implant compared to internal fixation. There are no hardware problems as all the hardware was removed. The high level of satisfaction in this group of patients reinforces the view that open arthrodesis using Charnley’s compression device, as opposed to ankle replacement or arthroscopic arthrodesis, continues to be the treatment of choice when there is severe varus or valgus deformity associated with the arthritis. [11] Although ankle arthrodesis may provide good early relief of pain, it is associated with premature deterioration of other joints of the foot and eventual arthritis, pain, and dysfunction. [12-13] In studies ranging in size from 12 to 101 patients, rates of successful primary ankle fusion of 80% to 100% have been reported earlier. [14-18] However an average follow up time of 2 years and 8 months is relatively short to comment on the future secondary osteoarthritic changes in the subtalar and mid foot joints.

To be considered as an alternative preferable to arthrodesis, a total ankle replacement should give better results than those presented here, without other disadvantages. Patients with rheumatoid arthritis and involvement of ankle may not meet the criteria for an ankle arthrodesis may be because they have involvement not only of the ankle but also of the small joints of the foot, so that these joints cannot compensate for the fused ankle. Therefore, patients with rheumatoid arthritis may be better candidates for the total ankle replacement. [19]

Conclusion

Subjectively and objectively, the patients with ankle fusion function quite well in activities of daily living provided that, they have enough compensatory motion in the Chopart’s and Lisfranc joints of the foot, the other ankle has a normal range of motion, they wear footwear with appropriate height. On the basis of these results, patients should be counseled that an ankle fusion will help to relieve pain and to improve overall function; however, it is a salvage procedure that will cause persistent alterations in gait with a potential for deterioration due to the development of ipsilateral hindfoot arthritis. Charnley’s compression device can still be considered as the fixator of choice compared to other modalities available with respect to cost, simplicity and good outcome.

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Address correspondence to: Asst Professor, Dept of Orthopaedics, PES Medical College, Kuppam, Chittore dist, Andra Pradesh, India, 517425. Email: drnarayan999@yahoo.com, Mob: 00 91 7702990696

1  Asst. Professor, Dept. of Orthopaedics, PES Medical College, Kuppam, Chittore dist., Andra Pradesh, India, 517425.
2  Asst. Professor, Dept. of Orthopaedics, PES Medical College, Kuppam, Chittore dist., Andra Pradesh, India, 517425.

© The Foot and Ankle Online Journal, 2012