Multiple Osteochondritis Dissecans of Knee Joint in a Patient with Wilson Disease, Focusing on Magnetic Resonance Findings
A 17-year-old man visited our orthopedic department with an acute attack of the left knee pain that had begun 2 days previously. The patient had experienced discomfort in both knees for the previous 7 months. A physical examination revealed diffuse swelling and tenderness of the left knee and motion limitation due to pain. Positive Wilson sign was evident and there seemed no other joint involvement but the both knees.\nThe patient had no record of previous medical history or family history of other diseases.\nPlain radiography was performed, which revealed symmetrical multiple OCD on femoral condyles of both knees (). Further evaluation was warranted for the unusual presentation of the disease. The patient was admitted and had a routine laboratory test prior to admission and it was his first time to take laboratory tests. His laboratory tests showed thrombocytopenia platelet count of 83×103/µL, prolonged prothrombin (PT)/activated partial prothrombin time (aPTT) of 14.7/45.3 sec. Further lab tests were carried out, and revealed deficit of coagulation factors V, XI, and XII (all 44%; normal range, 60% to 140%). Abdominal ultrasound revealed cirrhotic morphologic changes of the liver and splenomegaly. A suspicion of Wilson disease led to more additional laboratory tests for confirmation, which showed low ceruloplasmin (<4 mg/dL; normal range, 16.2 to 35.6 mg/dL), low serum copper (43 µg/dL; normal range, 70 to 145 µg/dL), and high urine copper (383 µg/dL: normal range, 15 to 60 µg/dL). Ophthalmologic examination showed Keyser-Fleischer rings in both corneas.\nHe was diagnosed with Wilson disease. Examinations of other commonly involved joints affected by Wilson disease, such as spine, hip, and wrists, were done and showed normal findings, and bone mineral density study also revealed normal values.\nAn MRI scan of the knee was performed to evaluate OCD lesions for its stage and treatment plans and to evaluate ligamentous or meniscal injury, if any. The MRI scan revealed characteristic bilateral symmetric OCD on both knees and symmetric detached OCD on the medial condyle of the bilateral femurs. Subchondral cysts were also seen on the medial femoral condyle of both knees and the trochlear dysplasia was observed in both femurs (-).\nArthroscopic debridement was performed for treatment of OCD.\nArthroscopic findings revealed OCD lesions on both medial and lateral femoral condyles, which were not apparently unstable at first under direct arthroscopic visualization. Using an arthroscopic probe, the medial femoral condyle lesion was found at the inferocentral portion of the medial femoral condyle; the lesion was unstable and already in a detached state (). The detached fragment too fragile to fixate was excised, and curettage and multiple drilling were performed subsequently (). The lesion on the lateral femoral condyle, also located at the inferocentral aspect, was stable and undetached, and was left untouched with the expectation of spontaneous healing ().\nMicroscopically, the section revealed articular cartilage with secondary calcification and synovial tissue (, ).\nAfter the arthroscopic treatment, the symptoms slowly diminished and at the 2-month postoperative follow-up, the patient was pain free with full range of motion of the knee. Ever since the diagnosis of the Wilson disease, the patient was on chelation therapy and had no recurrence of knee joint pain within the total 6 months of follow-up period.