FUNCTIONAL OUTCOMES OF MINIMALLY INVASIVE SURGICAL TECHNIQUES IN THE TREATMENT OF KNEE OSTEOARTHRITIS

Abstract

Background: Unicompartmental knee arthroplasty, high tibial osteotomy, and percutaneous surgical subchondral drilling of the proximal fibula have become alternative methods to total knee arthroplasty in the treatment of knee osteoarthritis. Comparative functional outcomes of these techniques and best patient selection criteria are however not clearly defined.Methods: A meta-analysis and systematic review of 23 studies with 1,847 patients was carried out. Knee Society Score, Western Ontario and McMaster Universities Osteoarthritis Index, gait analysis, patient-reported outcome measures, and quality-adjusted life years were used to measure functional outcomes. Exponential mixed effects meta-regression was used to model recovery kinetics. Stratified subgroup analyses with age, body mass index, level of activity, and preoperative varus alignment were conducted.Findings: Unicompartmental knee arthroplasty showed better 24 months Knee Society Score  and patient satisfaction  in older over 65 and obese patients with faster recovery  but increased rates of lateral compartment osteoarthritis progression  and aseptic loosening . High tibial osteotomy gained better gait biomechanics (symmetry index 91.2%) and was more popular in patients less than 50 years with high activity levels but had slower recovery (recovery half-life 5.59 months). The fastest recovery rate, lowest complication rate (3.0%), and the most cost-effective (incremental cost-effectiveness ratio $8,321 per quality-adjusted life year) was found with proximal fibular osteotomy with subchondral drilling. TKA demonstrated poorer results in the majority of measures.Conclusion: Minimally invasive surgery in knee osteoarthritis has a bivalent functional profile that requires the use of individualized patient selection. Unicompartmental knee arthroplasty should be applied in elderly and obese patients; high tibial osteotomy in young and active patients; proximal fibular osteotomy with subchondral drilling in patients with varus osteoarthritis in the early stages and need a fast and cost-effective recovery. To enhance functional outcomes, a treatment algorithm based on age, body mass index, activity level, and varus alignment is suggested.