Long-Term Functional Outcomes Following Minimally Invasive Total Knee Arthroplasty

Abstract

Minimally invasive total knee arthroplasty (TKA) has been adopted widely on the premise that a smaller, soft-tissue-sparing exposure accelerates early recovery without compromising the durable function conventional surgery delivers, yet that premise depends heavily on which of several distinct minimally invasive techniques -- quadriceps-sparing, mini-subvastus, midvastus, and mini-medial-parapatellar -is being discussed. This article synthesizes the randomized and long-term cohort literature comparing minimally invasive to standard medial parapatellar TKA, tracing the technique family from its original anatomical descriptions through more than a dozen meta-analyses of short- and mid-term outcomes to the sparser long-term follow-up data, including a ten-year cohort analysis, bearing on durable functional outcomes. Across independent meta-analyses, minimally invasive approaches consistently show reduced blood loss, faster straight-leg raise, and better early range of motion and knee scores, purchased at the cost of longer operative time and, for the quadriceps-sparing variant, a documented increase in malalignment risk. Whether these early advantages translate into better long-term function or satisfaction remains only partially answered, since the literature is dominated by follow-up under two years and underweights patient-reported outcomes. We conclude that minimally invasive TKA is a well-validated tool for shaping early recovery rather than a demonstrated long-term functional upgrade, and identify approach-specific, long-term, patient-reported-outcome-inclusive follow-up as the clearest remaining evidence gap.