Rapid chondrolysis following a lateral meniscectomy is a rare complication. We present the first reported case of rapid chondrolysis of the lateral compartment, which developed 6 months after a meniscus tear that was not surgically treated in a young 18-year-old professional rugby player. The possible hypotheses to explain this complication are presented, and certain previously published causes were excluded (iatrogenic during surgery, undiagnosed increased rotatory instability, chondrotoxicity of bupivacaine). Overloading of the cartilage surface of the lateral compartment from meniscal extrusion can cause cartilage necrosis.