Despite a much lower incidence of symptomatic osteoarthritis (OA) compared to other joints [1], ankle arthritis has been shown to have the same impact on a patients quality of life as arthritis of the hip joint and affects a younger population [2]. In the UK it has been reported that 29,000 patients per year with symptomatic ankle arthritis are currently seen by foot and ankle specialists [3] Surgical options include ankle fusion which provides pain relief but results in decreased function [4,5]. However fusion remains the accepted surgical option for managing ankle arthritis in the young, “high demand” patient. On the other hand, Total Ankle Arthroplasty (TAA) is steadily becoming an alternative treatment, although historically it was used in the elderly “low demand” patient or those with inflammatory arthritic conditions [6].

TAA dates back to 1970, following which a wave of fully cemented first generation constrained and unconstrained ankle replacements were developed (Table 1) [7]. Unfortunately significant early failure occurred with these TAA's mainly from loosening of the implant, leading to ankle instability and was attributed to poor implant design [8,9]. Second generation TAAs were introduced in the late 1980s with several modifications including a semi-constrained cementless design as well as both mobile and fixed bearing options [[9], [10], [11], [12]]. These modifications proved much more successful leading to good mid- and long-term results, and indeed some of these implants are still used today [13].

Analysis of second generation implant failures along with biomechanical studies has led to further modifications of these prostheses resulting in the development of third generation implants [14]. Third generation prosthesis may be classified as either two- or three-component and as fixed- or mobile-bearing designs [15]. The potential differences in functional outcome, survivorship and specific risks and complications between fixed and mobile-bearing designs is still though debated. Also, despite their inherent biomechanical differences, there are limited comparative studies and the registry data remain inconclusive [[16], [17], [18], [19], [20]]. Since 2013, fourth generation implants are being introduced. These have more durable polyethylene inserts and there is a better balance between constraint and mobility compared to previous designs. Fourth generation TAAs also allow a mismatch of sizes between tibial and talar components to accommodate patient specific anatomical variation [21].

We primarily performed a systematic review of the literature to assess the outcomes of TAA as defined by implant generation and bearing design to assess functional outcome, implant survivorship (at 2, 5, 10yrs), need for concurrent procedures, complication type/rates and revision surgery. A comparative analysis between bearing design and literature defined implant generations was completed to establish improvements between implants and aid informed decision making.