['This study had 2 aims: to determine whether arthroscopic partial meniscectomy improved symptoms in patients with a torn meniscus and severe degenerative change and to determine whether meniscectomy hastened the symptomatic progression of osteoarthritis in these patients.', 'An outcome study.', 'The study group consisted of 126 patients with Outerbridge grade IV degeneration (exposed bone) in the same compartment as a meniscal tear. These patients underwent arthroscopic partial meniscectomy. The control group consisted of 13 patients with exposed bone in the tibiofemoral compartment but intact menisci. They underwent washout. Data were obtained from a database of over 3,000 consecutive arthroscopies, patient medical records, and patients directly. Outcome was assessed a minimum of 12 months after surgery.', 'Meniscectomy improved symptoms initially in 82 cases (65%). At a median of 52 months after meniscectomy, 41 patients (32%) had undergone further surgery (39 total knee arthroplasty, 1 unicompartmental knee arthroplasty, and 1 tibial osteotomy). Fifty patients (40%) reported subjective improvement. The subjective outcome assessment by patients was consistent with patient activity, use of nonsteroidal anti-inflammatory drugs, and the Lysholm score. Meniscectomy did not hasten the progression of osteoarthritis because more patients required joint replacement after washout (P =.04), and the mean time to further surgery was greater for meniscectomy than for washout (74 months [standard error, 4.11] and 50 months [standard error, 12.3], respectively, P =.067).'] Does partial meniscectomy in the presence of severe osteoarthritis hasten the symptomatic progression of osteoarthritis?