Lateral Meniscal Injury After a Successful Medial Unicompartmental Knee Arthroplasty

A case of an active 52-year-old woman who, after a medial unicompartmental knee arthroplasty, began complaining of lateral joint line pain and a persistent knee effusion. A lateral meniscal tear was diagnosed clinically, and she underwent an arthroscopic partial meniscectomy that resolved her problems. This case demonstrates the importance of considering a meniscal problem as the cause of any unexplained joint line pain in the unoperated compartment after a successful unicompartmental knee arthroplasty and not simply attributing it to progression of degenerative change within the lateral compartment.