Presented at ACFAS 2010

1. REVISION TOTAL ANKLE ARTHROPLASTY BY CONVERSION TO TIBIAL STEMMED IMPLANT: A CASE REPORT J. George DeVries, DPM, FACFAS; Gregory C. Berlet, MD; Christopher F. Hyer, DPM, FACFAS ORTHOPEDIC FOOT & ANKLE CENTER | Columbus, OH | 614-895-8747 | www.orthofootankle.com REFERENCES: 1) Lau, JTC; Schon, LC; Mahomed, N: Differential practice of treating ankle arthritis in a general and specialty orthopaedic society. American Orthopaedic Foot and Ankle Society, 20th Annual Summer Meeting, Final Program 20:62, 2004. 2) Cornelis Doets, M.D.; Laurens W. van der Plaat, M.D.; Jan-Paul Klein, M.D. Medial malleolar osteotomy for the correction of varus deformity during total ankle arthroplasty: results in 15 ankles. Foot Ankle Int 29(2): 171-177, 2008. 3) Haskell, A; Mann, RA: Ankle arthroplasty with preoperative coronal plane deformity. Short-term results. Clin. Orthop. 424:98–103, 2004. 4) Spirt AA, Assal M, Hansen ST Jr. Complications and failures after total ankle arthroplasty. J Bone Joint Surg Am 86-A(6): 1172-1178, 2004. DISCUSSION: The authors present the first description of revision of a wide tibial base TAR with that of a tibial stemmed implant. There are several reasons the authors chose this type of conversion . First, the tibial stem allows for support through the medullary canal to compensate for the wide tibial resection of the original TAR. Second, the talar subsidence seen in the failure is compensated by the revision implant’s wide talar base. Third, there is modularity in the talar stem (10 or 14 mm) allows for maximum talar purchase. Fourth, the implantation jig used for the tibial stemmed implant allows for consistent implantation, even after loss of normal anatomic landmarks in revision cases. The authors have performed the revision of this type of implant to a tibial stemmed implant in 3 other patients. All of these have been successful in the short term other than the presented case, yielding a 75% success rate in this specific condition. In addition, 3 other implants have undergone this conversion as well, all initially successful for an overall 83.3% success rate in the short term. This case has two added points. First, it emphasizes the difficulty in the revision, and second it demonstrated the revision to arthrodesis for this implant with a long tibial stem. Even with the added bone resection needed, bulk allograft can be inserted and the entire construct. Is stable. CONCLUSION: In conclusion, as TAR continues to grow in popularity and the indications are expanded, the number of revision needed is likely to increase. The options for salvage are all technically demanding and require careful consideration from both the surgeon and the patient. INTRODUCTION: Total ankle replacement (TAR) is gaining acceptance since the introduction of 2 nd and 3 rd generation implants. (1) As surgeons gain experience and comfort with this procedure, the indications will expand. (2,3) This increase in implantation of TARs will inevitably lead to patients who have a failed total ankle. Once a patient has a failed implant, several options have been reported. The first is to do a polymer exchange with or without metallic component exchange, (4) arthrodesis, (5), and finally is conversion to a new implant. (6,7) This is a report of a failed TAR converted to a new implant, that also failed and was converted to an extended arthrodesis with a retrograde nail. LITERATURE REVIEW: Failure of a TAR happens between 7.5-13.2%, and may require grafting, revision, arthrodesis, or amputation. (4,8,9) Revision of the failed TAR is most commonly accomplished through polymer exchange. (4) This involves removing a fractured or worn polymer and replacing with a new one, which may be done in conjunction with re-balancing procedures. There are several case studies that have explored conversion of one implant to another. Myerson discusses the role of custom-designed stemmed implants for both primary or revision TAR. (10) Other authors have described exchanging the tibial metallic component of one system for another, while maintaining the talar base component. This can only be done in mobile bearing devices. (11) Two different authors and institutions have described the exchange of a previously implanted mobile bearing implant with a wide tibial base, fixed bearing design TAR, both with excellent results. (17,18) Another revision option is that of implant removal and arthrodesis. (9,11) Culpan et al. have found a high rate of fusion after failed TAR by using rigid internal fixation, and autograft, achieving primary fusion in 15/16 patients. (12) Another study evaluated a tibio-allograft-calcaneal arthrodesis using a retrograde locked nail. These authors found that in 3 patients, successful restoration of height and solid fusion could be achieved via this method. (14) External fixation for this complicated scenario has also been described in a study by Zarutsky et al. where the authors reviewed the results of salvage ankle arthrodesis in 43 patients. Included in this population was failed total ankle arthroplasty, and an overall stable outcome was achieved in 80.5%. (13) CASE STUDY: A 67 year old male with no significant past medical history presented to the Orthopedic Foot and Ankle Center with complaints of a painful TAR (Figure1). The patient had his original replacement done approximately 4 years previously at an outside institution. The patient had exhausted all conservative measures and elected to undergo conversion from his original TAR to a tibial stemmed implant. The goals of surgery was pain relief and functional improvement. The patient is currently 17 months out from the revision TAR. He had an early, uncomplicated course with a 5 tibial stem component, and prophylactic screw fixation of the medial malleolus (Figure 2). Then the patient developed swelling and erythema at his ankle after resuming athletic activity 6 months after surgery. At 7 months he was admitted to the hospital and put on long-term antibiotics. The erythema resolved, but after stopping antibiotics, the patient developed a draining abscess from the medial wound and erythema and swelling of the entire ankle at 10 months. He was treated with surgical incision and drainage, and initial negative pressure wound therapy. The patient was again put on long term antibiotics, but after stopping them, the patient again developed erythema and swelling. At 14 months he was treated with removal of the implant and an antibiotic spacer, as well as a short course of antibiotics (Figure 3). The patient was stable with out antibacterial medications, and at 15 months after the revision by conversion to tibial stemmed implant, the patient was treated with tibiotalocalcaneal arthrodesis with femoral head bulk allograft, bone morphogenetic protein-2, and a retrograde intramedullary nail (Figure 4). He is currently 17 months after the revision TAR, and 2 months out from extended arthrodesis. The patient is on no antibiotics, and currently has a stable hindfoot and ankle construct. 5) Thomason K, Eyres KS. A technique of fusion for failed total replacement of the ankle: tibio-allograft-calcaneal fusion with a locked retrograde intramedullary nail. J Bone Joint Surg Br 90-B(7):885-888, 2008. 6) Assal M, Greisberg J, Hansens ST Jr. Revision total ankle arthroplasty: conversion of new Jersey Low Contact Stress ™ to Agility ™: surgical technique and case report. Foot Ankle Int 25(12):922-925, 2004. 7) DiDomenico LA, Williams K. Revisional total ankle arthroplasty because of a large tibial bone cyst. J Foot Ankle Surg 47(5):453-456, 2008. 8) Valderrabano V, Hintermann, Dick W. Scandinavian total ankle replacement: A 3.7-year average follow-up of 65 patients. Clin Orthop Relat Res. 424:47-56, 2004. Figure 1 : Original failed TAR which was painful and had radiographic talar subsidence Figure 2 : Conversion to stemmed implant. Medial malleolar screws were re-placed prophylactically to prevent malleolar fracture Figure 3 : After revision TAR explantation, with cement antibiotic spacer Figure 4 : Revision tibiotalocalcaneal arthrodesis with bulk femoral head allograft and intramedullary nail 9) Wood PL, Prem H, Sutton C. Total ankle replacement: medium-term results in 200 Scandinavian total ankle replacements. J Bone Joint Surg Br 90(5):605-9, 2008. 10) Myerson MS, Won HY. Primary and revision total ankle replacement using custom-designed prostheses. Foot Ankle Clin 13(3):521-538, 2008. 11) Kharwadkar N, Harris NJ. Revision of STAR total ankle replacement to hybrid AES-STAR total ankle replacement – a report of two cases. Foot Ankle Surg 15(2):101-105, 2009. 12) Culpan P, Le Strat V, Piriou P, Judet T. Arthrodesis after failed total ankle replacement. J Bone Joint Surg Br 89-B(9):1178-1183, 2007. 13) Zarutsky E, Rush, SM, Schuberth JM. The use of circular wire fixation in the treatement of salvage ankle arthrodesis. J Foot Ankle Surg 44(1) 22-31, 2005.