[Modern three-piece total ankle replacement. Frequency and causes of luxation and premature wear of the polyethylene bearing]

Abstract

Luxation and excessive wear of the mobile bearing in modern three-piece total ankle replacement (TAR) is reported. We conducted a systematic review of studies to explore and discuss the rate and causes of these complications.A systematic review of studies since 2000 showed 26 studies with altogether 1,318 followed up TARs which we analyzed. Of these 1,318 TARs, 188 (14.3%) were revised and 56 (4.2%) complications with the mobile bearing were reported. A total of 39 cases (3%), i.e., 20.7% of all revisions, were revised due to failure of the mobile bearing, including 17 cases with subluxation (1.3%), 15 with asymmetric load of the bearing (1.1%), 10 with fracture of the polyethylene (PE) inlay (0.76%), 7 with massive PE wear (0.53%), and 7 with luxation of the meniscal bearing (0.53%).Complications due to the meniscal mobile bearing in TARs such as luxation, subluxation, massive wear, and fracture of the PE inlay are rare complications. The cause of these complications is regularly not found in the design of this three-piece total ankle replacement. Causes of failure of the mobile bearing are mostly found in incorrect indication, incorrect soft tissue balancing, incorrect positioning of components, implantation in ankles with hindfoot malalignment and ankle instability.