Evidence-based classification of complications in total ankle arthroplasty.

BACKGROUND:
Total ankle arthroplasty (TAA) has become a viable treatment for end-stage ankle arthrosis. Current literature on survival rates and complications of TAA consist of mostly retrospective Level IV papers that do not provide a system for classifying complications. The aim of the current review is to provide a summary of TAA implant survival and complication rates from current literature on outcomes of second or third generation ankle prostheses and subsequently propose a classification system.

METHODS:
A literature review was used to identify articles reporting complications and failures of TAA ankle prostheses. Inclusion criteria included studies with at least 25 cases and a minimum of 24 months followup.

RESULTS:
Twenty studies met the inclusion criteria. The percentage of failed TAA reported for the short- and intermediate-term followup in this review ranged from 1.3 to 32.3 % with an overall mean of 12.4 % failure at 64 months. Nine main complications of TAA were identified.

CONCLUSION:
Deep infection, aseptic loosening and implant failure should be considered ;;high-grade'' complications since they will result in failure greater than 50% of the time. Technical error, subsidence and postoperative bone fracture should be considered "medium-grade'', while intra-op bone fractures and wound healing problems should be considered "low-grade''. We believe this review provides the groundwork for uniform complication reporting in TAA and allows the development of a classification system that will provide prognostic information that may serve to guide postoperative care of patients receiving TAA.