Synovial Chondromatosis of the Knee Joint Secondary to Osteoarthritis Treated with Total Knee Arthroplasty and Excision: A Rare Case Report

Introduction: Synovial chondromatosis is a rare, benign condition characterized by the formation of multiple cartilaginous nodules within the synovial membrane leading to attached or unattached loose body. It can arise either spontaneously (idiopathic) or secondary to osteoarthritis (OA). The aim of this study is to highlight the importance of early diagnosis and effective management of synovial chondromatosis. Case presentation: A 66-years-old female complained of pain in the left knee for a year accompanied with swelling and stiffness 6 months later and limitation to walk occurs 8 months since the first complaint. An X-Ray of left knee showed multiple mass calcification and narrowing joint spaces. The patient treated with total knee arthroplasty due to severe joint damage and conducted complete evacuation of loose bodies with excision and performed a biopsy, which confirmed the diagnosis. Range of motion (ROM) exercise and weight bearing was started in second post operative day and proper education was given to the patient before discharge. Following 2 months follow up, patient left knee flexion extension ROM ranged from 0-150˚ and no further swelling experienced by the patient. Discussion: The rarity of synovial chondromatosis results in a delay in the diagnosis. Atypical symptoms of synovial chondromatosis are commonly confused with OA itself. Secondary synovial chondromatosis is associated with joint abnormalities, such as mechanical or arthritic conditions, as presented in this case. The choice of management is based on the patient’s clinical condition, degree of joint damage, and the involvement of the loose bodies. Early detection may allow for management with arthroscopic debridement. But, if severe joint damage takes place, total knee arthroplasty following the removal of loose bodies is an effective treatment that give favorable result with satisfactory functional outcomes. Conclusion: Synovial chondromatosis, a rare benign synovial disease-causing knee pain and limited motion, was successfully managed in this case by removing loose bodies during total knee arthroplasty, with the patient showing significant improvement, highlighting the need for regular exercise and follow-up to prevent recurrence. Clinical Importance: Early diagnosis of synovial chondromatosis is crucial to prevent severe joint damage, and total knee arthroplasty with removal of loose bodies can yield excellent functional outcomes. Keywords: excision, synovial chondromatosis, osteoarthritis, total knee arthroplasty