Tomori Yuji, Nanno Mitsuhiko, Takai Shinro
Departments of Orthopaedic Surgery, Nippon Medical School Musashi Kosugi Hospital, Kanagawa.
Departments of Orthopaedic Surgery, Ukima Central Hospital.
Medicine (Baltimore). 2019 Aug;98(33):e16900. doi: 10.1097/MD.0000000000016900.
Spontaneous closed extensor tendon rupture is a rare complication of Kienböck disease with only 23 cases reported in the English literature.
We present a case of painless attritional rupture of the extensor tendons of the right fourth finger in a 69-year-old woman with Kienböck disease and review reported cases of Kienböck disease with subcutaneous closed tendon rupture.
Physical examination had shown mild painless swelling of the dorsum of the right hand. Plain radiographs showed a dorsally displaced fragment of collapsed lunate bone fracture (Lichtman grade IIIb). Although surgery was recommended, the patient did not desire surgery because she had no pain and no interference with the activities of daily living. Six months later, however, the patient returned to our hospital with complaints of loss of spontaneous extension of the fourth finger. CT and MRI showed aseptic necrosis and large dorsally displaced fragments of the lunate under the extensor tendons of the fingers, suggesting a subcutaneous fourth extensor tendon rupture.
Surgery was performed to achieve functional recovery of the ring extensor and to prevent further subcutaneous tendon rupture. The extensor digitorum communis (EDC) of the ring finger was found to be ruptured and the EDCs to the third and fifth fingers were frayed due to attrition from the protrusion of the dorsal fragmented lunate bone. Inspection of the floor of the compartment revealed that the dorsally displaced fragment of the lunate bone had perforated the wrist capsule and protruded into the fourth compartment. The dorsal and volar fragments of the lunate bone were excised completely and scaphocapitate arthrodesis followed by the reconstruction of the fourth extensor tendon was performed.
A year after the surgery, radiography showed complete union of the scaphocapitate arthrodesis. The joint motion reached 45% of normal without any pain and there was full active extension of the fourth finger.
Because dorsally displacement of collapsed lunate bone fragments is a risk factor for attritional closed rupture of tendons, radiography, and MRI are essential to diagnose and to treat any closed tendon rupture.
自发性闭合性伸肌腱断裂是月骨无菌性坏死疾病的一种罕见并发症，英文文献中仅报道了23例。
我们报告了一例69岁患有月骨无菌性坏死疾病的女性患者，其右手环指伸肌腱出现无痛性磨损断裂，并回顾了已报道的月骨无菌性坏死伴皮下闭合性肌腱断裂的病例。
体格检查显示右手背有轻度无痛性肿胀。X线平片显示月骨塌陷骨折碎片向背侧移位（Lichtman IIIb级）。尽管建议手术治疗，但患者因无疼痛且不影响日常生活活动而不希望手术。然而，6个月后，患者因环指自发伸展丧失前来我院就诊。CT和MRI显示手指伸肌腱下方月骨无菌性坏死且有大的背侧移位碎片，提示皮下环指伸肌腱断裂。
进行手术以实现环指伸肌功能恢复并防止肌腱进一步皮下断裂。发现环指指总伸肌断裂，第三和第五指的指总伸肌因背侧碎骨突出的磨损而磨损。检查腱鞘底部发现月骨背侧移位碎片已穿透腕关节囊并突入第四腱鞘。完全切除月骨的背侧和掌侧碎片，进行舟头关节融合术，随后重建第四伸肌腱。
术后一年，X线显示舟头关节融合完全愈合。关节活动度达到正常的45%，无疼痛，环指主动伸展完全恢复。
由于塌陷的月骨碎片背侧移位是肌腱磨损性闭合断裂的危险因素，X线平片和MRI对于诊断和治疗任何闭合性肌腱断裂至关重要。
