Anterior cruciate ligament rupture in gouty arthritis.

A 34-year-old male presented with right knee instability without any trauma. He had been diagnosed with right knee gouty arthritis 2 years prior. An arthroscopic examination revealed abundant calcific material deposited around the knee joint, including in the ACL tissue, and that the ACL was torn at the femoral attachment site. Treatment involved a synovectomy to remove calcific material, followed by an ACL reconstruction. Histology evaluation revealed gouty arthritis with the presence of tophi in the synovium, soft tissue, and ACL tissue. The case presented here indicates the possibility of pathologic rupture of the ACL associated with gouty tophus infiltration of that ligament. Level of evidence IV.