Minimally invasive total knee arthroplasty using a cruciate-retaining knee system: A 3–5 year study with comparison to a standard approach

Abstract

Background/PurposeMinimally invasive surgery (MIS) for total knee arthroplasty (TKA) is a recent development. Most published studies of the procedure report on early experience, and have emphasized early recovery and good outcomes in the first 3 months to 1 year. MethodsThis retrospective study compared 121 TKA done through a minimally invasive midvastus approach with 50 TKA done using a standard medial parapatellar approach, and assessed the results at a minimum follow-up of 3–5 years. A cemented U2 cruciate-retaining knee (United, Taipei, Taiwan) was used in both patient groups. ResultsThe postoperative mean knee score and function score were 95.3 (range, 69–110) and 82.3 (range, 20–100) respectively in the MIS TKA group, compared to 94 (range, 78–00) and 82 (range, 30–100) for the control group (standard approach). The postoperative Knee Society scores did not differ significantly between the two groups. The postoperative mean range of motion was 113.8° (range, 70–145°) in the MIS TKA group compared with 105.1° (range, 40–130°) for the control group, and the difference was significant (p < 0.05). There was no difference in postoperative coronal X-ray alignment between the two groups, neither were there any outliers in the component alignment and component size in the MIS TKA group. There were three knees (2%) with anterior femoral notching in the MIS TKA group compared to no knee notching for the control group. ConclusionThough the MIS TKA was technically demanding, the outcomes at 3–5 years’ follow-up were at least as good as those obtained with the standard medial parapatellar TKA procedure.