Arthroscopic partial meniscectomy in patients with Kellgren-Lawrence grade 3 osteoarthritis shows clinically meaningful improvement in outcomes

PURPOSE The purpose of this study is to evaluate patient-reported outcome measures (PROMs) following arthroscopic partial meniscectomy (APM) in patients with Kellgren-Lawrence (KL) grade 3 on preoperative knee radiographs and a symptomatic meniscal tear. METHODS This was a retrospective study design using prospectively collected data from a single institution. Patients were included if they had KL grade 3 osteoarthritis on preoperative radiographs of the knee and completed a trial of nonoperative treatment for at least 6 weeks prior to APM. Subjects were excluded if they had inflammatory arthritis, incomplete preoperative and/or 1-year postoperative follow-up data, repeat knee arthroscopy, and concomitant ligamentous injury. Statistical analyses used PROMs, preoperatively and up to 2-years postoperatively, to assess improvement utilizing scales with previously established thresholds including minimal clinically important difference (MCID) and substantial clinical benefit (SCB). RESULTS Eighty-two patients met the eligibility criteria (49 women (60%), mean [SD] age, 53.1 [9.3] years). At 1-year follow-up, most patients achieved MCID: 73% in Knee Injury and Osteoarthritis Outcome Score (KOOS) Pain, 66% in KOOS symptoms and 78% in KOOS ADL. These improvements were similar at 2-year follow-up: 75%, 72% and 79%, in each subscale, respectively. SCB was also demonstrated 1-year postoperatively, with 56%, 73% and 71% achieving SCB for the KOOS Pain, Symptoms and ADL subscales, respectively. These results largely persisted at 2-years follow-up. Visual Analog Scale (VAS) scores also improved at 1- and 2-year postoperative periods with mean improvements from baseline of 2.80 and 2.87 points, respectively. Marx Activity Score (MAS) decreased on average from baseline to 1- and 2-year follow-up. CONCLUSION At a minimum of 1-year follow-up, most patients with KL grade 3 and a meniscal tear achieved MCID and SCB in KOOS pain, KOOS symptoms and KOOS ADL indicating meaningful outcome improvement for these patients. LEVEL OF EVIDENCE Level IV: Therapeutic Case Series