A retrospective study of articular surface mounting computer-assisted total knee arthroplasty in alignment, knee function, and survival

BackgroundHong Kong Chinese exhibits a greater varus lower limb mechanical axis and coronal bowing when compared to Caucasians. This anatomical difference may affect the accuracy of bone cuts in total knee arthroplasty (TKA) using western anatomy-based intramedullary TKA cutting jigs. Use of computer navigation may avoid suboptimal cuts due to altered anatomy. This is the first study evaluating clinical function, radiological alignment and long-term survival of computer-assisted TKA amongst Hong Kong Chinese patients. MethodsRetrospective study comparing articular surface mounting computer-assisted TKA (ASM-CATKA) and conventional TKA performed in a single centre from 2008 to 2010. Patients were followed up for assessment of clinical parameters including range of motion, Knee Society Knee score, and radiological parameters such as limb alignment, component alignment, and survival. ResultsSeventy-five patients were included in this study. Baseline clinical and radiological data were similar between groups. The computer-navigated group had superior radiological mechanical alignment (p < 0.001), tibial component alignment (p = 0.016) and femoral component alignment (p < 0.01) when compared to conventional TKA. There were no differences in knee scores (p = 0.488), range of motion (p = 0.432) and survival at 117 months (p = 0.986) between the two groups. ConclusionThis retrospective study showed that ASM-CATKA was more accurate in achieving neutral mechanical axis and component alignment amongst Hong Kong Chinese. Clinical outcomes and implant survival were comparable.