SLR - June 2016 - James Whelan

Conversion of Tibiotalar Arthrodesis to Total Ankle Arthroplasty

Reference: Pellegrini MJ, Schiff AP, Adams SB Jr, Queen RM, DeOrio JK, Nunley JA 2nd, Easley ME. Conversion of Tibiotalar Arthrodesis to Total Ankle Arthroplasty. J Bone Joint Surg Am. 2015 Dec 16; 97(24):2004–13.

Scientific Literature Review

Reviewed By: James Whelan, DPM
Residency Program: Wheaton Franciscan Healthcare – St. Joseph Hospital, Milwaukee, WI

Podiatric Relevance: Tibiotalar arthrodesis remains a more popular surgical treatment option to total ankle arthroplasty for end-stage ankle arthritis despite comparable pain relief outcomes. The podiatric surgeon must be equipped to address poor outcomes following primary ankle arthrodesis. The evidence currently available is lacking on how best to approach failed ankle arthrodesis. In this study, the authors attempt to identify patient-reported outcomes and complications following conversion of failed ankle arthrodesis to total ankle arthroplasty. This study provides evidence that conversion total ankle arthroplasty is a viable option for failed ankle arthrodesis.

Methods: A prospective cohort study was performed reviewing 23 total ankle arthroplasties performed in patients who had experienced complications from ankle arthrodesis for end-stage ankle arthritis. The total ankle arthroplasty procedures were performed using the STAR ankle, the INBONE or the Salto Talaris implants. Concomitant procedures were required in 78 percent of cases, most of which included prophylactic malleolar fixation, subtalar fusion and posterior muscle compartment lengthening procedures. Statistical analyses were used to evaluate and compare patients pre- and postoperatively in regards to pain and function. Radiographic assessment to evaluate for complications was compared from initial weightbearing radiographs to those taken at the most recent follow-up evaluation.

Results: Patients had significant improvement in VAS pain scores from preoperative evaluation to most recent follow-up (score change of 65.7 to 18.3). Five patients were absolutely pain free. The mean SMFA bother index significantly improved from 55 preoperatively to 30.6 at the most recent follow-up visit. The patients had significant improvement in SMFA function index from preoperative evaluation to the most recent follow-up (index change of 46.7 to 25.4). The mean SF-36 total score improved from 37.7 to 56.4. Eighty seven percent of patients retained their metal implants at final follow-up. Forty three percent of patients had minor complications that did not require additional surgical intervention. Thirty percent of patients required additional surgery. Three total ankle replacements (13 percent) required talar component revision following progressive talar subsidence. Both patients with ankle arthrodesis associated with fibular resection failed conversion to total ankle arthroplasty.

Conclusions: Patients who underwent conversion of ankle arthrodesis to total ankle arthroplasty had pain relief and improved function with short-term follow-up. The foot and ankle surgeon must be cognizant of the high rate of complications associated with conversion to total ankle arthroplasty, especially with talar subsidence. Prophylactic malleolar fixation is recommended when performing conversion to total ankle arthroplasty. Conversion to total ankle arthroplasty is not recommended for ankle arthrodeses that included resection of the distal fibula. In this study, the authors provide patient-reported outcomes and complications following conversion total ankle arthroplasty to better equip the foot and ankle surgeon when dealing with failed ankle arthrodesis.

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