Abstract：
We report on a 40-year-old male with a 9-month-long history of snapping of his right hip caused by a previously undescribed etiology of internal extra-articular snapping hip, namely due to a localized tenosynovial giant cell tumor. Both dynamic ultrasound evaluation and MRI proved to be crucial in the diagnosis of this rare entity. Auto-provocation of the snapping showed an anterior hip mass moving posteriorly to the psoas tendon which elucidated the pain and clicking sensation. Subsequent MRI demonstrated a peripheral low-intensity rim due to hemosiderin deposition around the synovial mass which is indicative for pigmented villonodular tenosynovitis. Treatment consisted of arthroscopic shaver burr resection. Immediately postoperatively, the snapping sensation could not be provoked anymore by the patient. The purpose of reporting on this case report is to emphasize several successive learning points. First, dynamic ultrasound aids in diagnosis and differentiation of the types of snapping hip. Second, specific MRI features are suggestive of tenosynovial giant cell tumor, recognizing these traits may prevent delayed diagnosis and subsequent aggravated clinical course. Third, localized pigmented villonodular tenosynovitis around the hip may present as an internal extra-articular snapping hip and is of consideration in the differential diagnosis of recurrent snapping hip.
摘要：
我们报道了一名40岁的男性，他有9个月的右髋部骨折史，这是由于先前未描述的内部关节外骨折的病因引起的，即由于局部的腱鞘巨细胞瘤。动态超声评估和MRI都被证明对这种罕见实体的诊断至关重要。折断的自动激发显示，前髋关节肿块向后移动到腰肌腱，从而阐明了疼痛和点击感。随后的MRI显示，由于滑膜周围的含铁血黄素沉积，导致周围的低强度边缘，这表明色素沉着的绒毛结节性腱鞘炎。治疗包括关节镜剃须刀毛刺切除术。术后立即，病人再也无法激起这种突然的感觉了。报告此病例报告的目的是强调几个连续的学习要点。首先,动态超声有助于诊断和鉴别髋关节的类型。第二,特定的MRI特征提示腱膜巨细胞瘤，识别这些特征可能会阻止诊断延迟和随后加重的临床过程。第三，髋关节周围的局部色素性绒毛结节性腱鞘炎可能表现为内部关节外断裂髋关节，在复发性断裂髋关节的鉴别诊断中需要考虑。
