Predictors of Successful Treatment 1 Year After Arthroscopic Partial Meniscectomy

Arthroscopic partial meniscectomy (APM) is one of the most common orthopaedic procedures. Understanding factors that predict better patient-reported outcomes is important for guiding patient and clinician decision-making. The purpose of this study was to evaluate predictors of pain and function after APM in a large, multisite, academic health system cohort. METHODS: We prospectively enrolled 665 patients who were ≥40 years of age and who had APM without any concomitant ligament or cartilage-resurfacing procedures. There were 486 subjects (73%) who completed baseline and follow-up questionnaires including demographic variables (age, sex, body mass index [BMI], education level), surgical findings (meniscal tear type, articular cartilage grade), and patient-reported outcomes (Knee injury and Osteoarthritis Outcome Score [KOOS] Pain, Physical Function Short Form [PS], and knee-related Quality of Life [QOL]; and Veterans RAND 12-Item [VR-12] Mental Component Score [MCS] and Physical Component Score [PCS]). We constructed multivariable statistical models to assess predictors of improvement in patient-reported outcomes, as well as a model to assess predictors of a successful improvement of at least 10 points in either KOOS Pain or KOOS-PS. There were clinically important and significant improvements (p < 0.001) in all patient-reported outcomes from baseline to the 1-year follow-up. The following factors predicted less improvement in at least 1 patient-reported outcome: higher baseline score, higher BMI, older age, less education, current smoking, lower VR-12 MCS, prior ipsilateral surgical procedure, bipolar medial compartment cartilage lesions, and a lateral meniscal tear. Eighty-three percent of subjects had a successful improvement of 10 points in either KOOS Pain or KOOS-PS. The odds of successful improvement were lower in patients with a medial meniscal root tear, a lateral meniscal tear, or higher baseline KOOS Pain score. CONCLUSIONS: Eighty-three percent of patients improved by at least 10 points in pain and function after APM. Patients with a medial meniscal root tear or a lateral meniscal tear had decreased odds of a clinically important improvement in pain or function after APM. Increased BMI, smoking, and worse VR-12 MCS are potentially modifiable risk factors that predict less improvement after APM and warrant further study. LEVEL OF EVIDENCE: Prognostic Level I. See Instructions for Authors for a complete description of levels of evidence.