Uncontrolled diabetes as a potential risk factor in tibiotalocalcaneal fusion using a retrograde intramedullary nail

Background: Tibiotalocalcaneal (TTC) fusion using a retrograde intramedullary (IM) nail is an effective salvage option for terminal-stage hindfoot problems. However, as many patients who receive TTC fusion bear unfavorable medical comorbidities, the risk of nonunion, infection and other complications increases. This study was performed to identify the factors influencing outcomes after TTC fusion using a retrograde IM nail. Methods: Between September 2008 and February 2012, 34 consecutive patients received TTC fusion using a retrograde IM nail for limb salvage. All patients had a minimum follow-up of two years. Throughout follow-up, standard ankle radiography was performed along with clinical outcome assessment using a visual analog scale (VAS) for pain, the American Orthopaedic Foot and Ankle Society Ankle-Hind Foot Scale (AOFAS A/H scale) and the Foot and Ankle Outcome Score (FAOS). For the retrospective analysis, demographic factors, preoperative medical status, laboratory markers, and etiology were comprehensively reviewed using medical records. The success of the index operation was determined using clinical and radiological outcomes. Finally, the effect of each factor on failure after the operation was analyzed using univariate logistic regression. Results: In a mean of seven months, 82% (28/34) achieved union, as evaluated by standard radiography. All clinical outcome parameters improved significantly after the operation, including VAS, AOFAS A/H scale, and FAOS (P < 0.001). At the last follow-up, five cases of nonunion with less than AOFAS A/H scale of 80 and two cases of below knee amputation due to uncontrolled infection were determined to be failures. None of the factors (etiology, demographics, laboratory markers and medical status) significantly influenced failures. However, uncontrolled DM significantly increased the failure rate with an odds ratio of 10 (P = 0.029). Conclusions: TTC fusion with a retrograde intramedullary nail is a successful treatment for complicated hindfoot problems such as traumatic osteoarthritis, Charcot arthropathy and failed TAA. However, it should be used judiciously in patients with uncontrolled DM, as the risk of failure increases. Design: Retrospective cohort study.