The value of arthroscopic partial meniscectomy in the severely arthritic knee has been questioned. Some authors suggest that it may result in progression of osteoarthritis precipitating the need for joint replacement and that symptomatic improvement may occur from lavage alone.

126 patients with a torn meniscus and Outerbridge grade IV changes in the same compartment underwent arthroscopic partial meniscectomy and limited debridement of unstable articular cartilage. The indication for surgery was a symptomatic meniscal tear not osteoarthritis. A control group consisted of 13 patients with grade IV changes and intact but frayed menisci who underwent washout alone. Mean age and follow up were similar in the two groups.

Initially meniscectomy improved symptoms in 82 cases (65%). Symptoms were unchanged in 26 cases (21%) and were made worse in 18 cases (14%). At a mean follow up of 55 months, 50 patients (40%) felt their knees were better than they were preoperatively. Their mean Lysholm score was 75. 5. 35 knees (28%) were not improved (mean Lysholm socre 59). 41 patients (32%) had undergone further surgery: 39 total knee replacements, 1 unicompartmental knee replacement and 1 tibial osteotomy. Older patients, those with varus/ valgus malalignment, and those with exposed bone on both articular surfaces fared worse.

Outcome following meniscectomy was better than outcome following washout alone: more patients reported an improvement after meniscectomy and fewer had undergone further surgery on their knees (p=0. 04). The median time between arthroscopy and the decisions for joint replacement was the same in both groups (8 months in the meniscectomy group and 7. 5 months in the washout group) indicating meniscectomy did not precipitate joint replacement.

These results suggest that arthroscopic partial men-iscectomy in the presence of Outerbridge grade IV changes can result in satisfactory long term outcomes for many patients, is more effective than washout alone and does not precipitate the need for joint replacement.