Efficacy, Safety, and Functional Impact of Total Knee Arthroplasty in the Treatment of Unilateral Knee Osteoarthritis: A Systematic Review

Objective

To conduct a systematic review of the scientific literature to evaluate the efficacy, safety, and functional impact of total knee arthroplasty (TKA) in the treatment of unilateral knee osteoarthritis. The review aims to synthesize evidence on pain reduction, improvements in quality of life, restoration of functional capacity, return to daily activities, and to discuss current surgical indication criteria and clinical implications in patients with isolated joint degeneration.

Methods

This review followed PRISMA guidelines and included studies published between January 2000 and May 2025, identified through searches in PubMed/MEDLINE, Scopus, Web of Science, and Embase. Eligible studies were randomized controlled trials, cohort studies, observational studies, and systematic reviews involving patients undergoing TKA for unilateral knee osteoarthritis. Data extraction was performed using a standardized protocol. Thematic synthesis was organized into three domains: (1) functional outcomes and safety in elderly patients, (2) ligament preservation and biomechanical considerations, and (3) fixation strategies in complex surgical scenarios. Risk of bias was assessed using RoB 2.0, NOS, and AMSTAR 2 tools.

Results

Thirty studies met the inclusion criteria. Evidence indicates that TKA provides significant improvements in pain relief, functional recovery, and quality of life in patients with unilateral knee OA, including those over 75 years of age. Age alone was not associated with increased complication rates. Cementless implants showed promising fixation outcomes in select elderly populations. Ligament-preserving techniques, especially PCL-retaining approaches, were associated with enhanced proprioception and biomechanical integrity. In complex cases, metaphyseal fixation with porous-coated components and patient-specific strategies improved implant stability and long-term outcomes.

Conclusion

Total knee arthroplasty is a safe and effective surgical option for the treatment of unilateral knee osteoarthritis. The procedure yields substantial functional and quality-of-life benefits when applied using individualized surgical planning, appropriate prosthesis selection, and evidence-based rehabilitation. Advanced age should not be considered a contraindication. Future research should aim to standardize fixation criteria and expand data on long-term outcomes in specific subgroups.