Total ankle replacement (TAR) outcomes have improved in treating ankle osteoarthritis, although complication rates are higher than for hip and knee arthroplasties. Modern implant designs are typically categorized into two groups based on the mobility of the polyethylene component: mobile bearing implants (MBI) and fixed bearing implants (FBI). The most common surgical approach is anterior, but a lateral approach is also used.

The aims of this doctoral thesis were to evaluate the functional and radiological outcomes, patient satisfaction, and implant survival of TAR using a trabecular-coated FBI model with a lateral approach (Zimmer Trabecular Total Ankle, Zimmer, TMTA, Warsaw, IN) and an older MBI model (Ceramic Coated Implant; Wright Medical Technology, CCI, Arlington, TN, USA) with the traditional anterior approach. We also investigated the motion of the polyethylene insert relative to the tibial component in the MBI implants using cone-beam computed tomography (CBCT). Lastly, we evaluated the incidence of peri-implant osteolysis associated with a new surgical technique and implant model, TMTA.

Based on the results of our studies, we conclude that using the FBI model achieved better outcomes in terms of patient satisfaction, pain management and implant survival. Additionally, the lateral approach combined with an external frame allowed for correction of more complex deformities and enabled more precise alignment. We also demonstrated that the incidence of periprosthetic osteolysis is significantly lower when using the new trabecular-coated FBI. Consequently, the need for additional procedures due to osteolysis was reduced.

Based on our findings, we recommend centralizing TAR operations in experienced centres, shifting to modern implant designs and adopting advanced surgical techniques to achieve better treatment outcomes.