Chung Jong-Won, Lee Soon-Hyuck, Han Seung-Beom, Hwang Hyun-Jung, Lee Dae-Hee
Department of Orthopedic Surgery, Korea University Anam Hospital, Korea University College of Medicine, Seoul, Korea.
Orthopedics. 2011 Jan 1;34(2):136. doi: 10.3928/01477447-20101221-26.
A woman presented with knee pain and locking. Pain was exacerbated at the end of the range of motion, especially during extension, with locking symptoms similar to those associated with a meniscus bucket handle tear. Ligamentous laxity was not definite. Plain radiographs showed multiple calcified loose bodies. Magnetic resonance imaging (MRI) showed a lobulated mass that was hypointense to muscle on T1-weighted sequences and hyperintense to muscle on T2-weighted sequences in the anterior cruciate ligament (ACL). Arthroscopically, multiple loose bodies were observed in the intercondylar notch and posterolateral compartment. A huge mass replaced the normal ACL and was caught in the intercondylar notch. The mass in the intercondylar notch caused loss of extension range of motion (ROM) because the piece caused a mechanical blockage. However, the loss of flexion ROM was likely caused by a loss of elasticity of the ligament rather than mechanical blockage. We resected the ACL mass, and removed the free bodies from the posterolateral corner. It was not possible to preserve the ACL fibers. Histological examination confirmed a diagnosis of osteochondromatosis. All symptoms resolved postoperatively. At 20 months postoperatively, the patient was pain free and had regained full knee motion without recurrence evidenced by follow-up MRI. However, ACL removal caused the knee instability. To date the patient has not undergone ACL reconstruction because she prefers conservative treatment and has experienced little discomfort in activities of daily living. To our knowledge, this is the first report to describe synovial osteochondromatosis wholly replacing the ACL fibers and causing mechanical blocking of both extension and flexion.
一名女性患者出现膝关节疼痛和交锁症状。在活动范围末端疼痛加剧，尤其是在伸展时，交锁症状类似于半月板桶柄状撕裂。韧带松弛情况不明确。X线平片显示多个钙化的游离体。磁共振成像（MRI）显示在前交叉韧带（ACL）处有一个分叶状肿块，在T1加权序列上相对于肌肉呈低信号，在T2加权序列上相对于肌肉呈高信号。关节镜检查发现髁间切迹和后外侧间室有多个游离体。一个巨大的肿块取代了正常的ACL，并卡在髁间切迹处。髁间切迹处的肿块导致伸展活动范围（ROM）丧失，因为该肿块造成了机械性阻挡。然而，屈曲ROM的丧失可能是由于韧带弹性丧失而非机械性阻挡所致。我们切除了ACL肿块，并从后外侧角取出了游离体。无法保留ACL纤维。组织学检查确诊为滑膜骨软骨瘤病。术后所有症状均消失。术后20个月，患者无疼痛，膝关节活动完全恢复，随访MRI未发现复发。然而，ACL切除导致膝关节不稳定。迄今为止，该患者尚未接受ACL重建，因为她倾向于保守治疗，且日常生活活动中几乎没有不适。据我们所知，这是第一例描述滑膜骨软骨瘤病完全取代ACL纤维并导致伸展和屈曲机械性阻挡的报告。
