Non-Surgical and Surgical Treatment of Chronic Pain in Older Adults with Unilateral or Index-Knee Osteoarthritis: A Systematic Review

Abstract

Joao Pedro Brandao Wantuil, Fillipo Leite Prazeres , Giovani Jose Coury Costa and Lucas Tavares Domingos

Background: Treatment of chronic knee osteoarthritis pain in older adults spans education, exercise, medication, injections, osteotomy and arthroplasty. Trials studying unilateral disease or bilateral disease assessed through an index knee are under-represented and rarely synthesized across the full treatment pathway.

Methods: PubMed, the MEDLINE-indexed subset of PubMed, Google Scholar and SciELO were searched for free- full-text original studies published from January 2015 to July 2026. Systematic reviews, meta-analyses, protocols and irrelevant reports were excluded. A PICO framework guided eligibility. Non-surgical pain outcomes were pooled when clinically comparable; surgical evidence was synthesized narratively because interventions, comparators and outcomes were heterogeneous.

Results: Twenty-seven studies were included: 19 non-surgical and eight surgical. Three non-surgical comparisons were meta-analysed in the primary synthesis (n=202), yielding Hedges' g -0.56 (95% CI -1.18 to 0.06; I2=0%). A contextual sensitivity analysis adding open-label placebo (n=262) gave g -0.56 (95% CI -0.96 to -0.15). Randomized surgical evidence showed that total knee arthroplasty improved pain and function relative to non-surgical care but increased serious adverse events, whereas partial and total knee replacement had similar 5-year clinically important outcomes in isolated medial compartment disease.

Conclusions: Exercise, education and self-management remain the core first-line treatment, but the review now explicitly integrates the surgical pathway. Total knee arthroplasty is effective for appropriately selected advanced disease, unicompartmental arthroplasty is suitable for isolated unicompartmental osteoarthritis, and high tibial osteotomy may be reasonable in carefully selected varus medial-compartment disease. Figure layout and evidence presentation were revised to improve readability and the PICO framework is now explicit.

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