Acute meniscal injury following successful unicompartmental knee arthroplasty.

The case of an active 53-year-old man with a well-functioning unicompartmental knee arthroplasty who suffered an acute athletic injury to the knee is described. A mechanical problem was diagnosed and he was successfully treated by arthroscopic partial lateral meniscectomy for a displaced meniscal tear. This case points to an important difference noted by history and physical examination between an acute injury to the unreplaced compartment of a knee with a unicompartmental knee arthroplasty and progression of the arthritic process.