Griffin Courtney, Mochal-King Cathleen A, Grissett G P, Shores Andy
J Am Vet Med Assoc. 2019 Sep 1;255(5):591-594. doi: 10.2460/javma.255.5.591.
A 3-year-old 639-kg (1,406-lb) American bucking bull was examined because of a 4-day history of right forelimb lameness that began after the bull sustained an injury to the right shoulder region while exiting the chute during a rodeo.
A 10 × 10-cm soft tissue swelling was present over the right shoulder region. Ultrasonographically, the contour of the scapular spine, bicipital bursa, bicipital tendon, and greater tubercle of the humerus appeared unremarkable; the swelling appeared to be a hematoma overlying the distal aspect of the scapula. No external wounds, palpable joint effusion, or swellings were noted on examination of the distal portions of the limbs. The bull developed atrophy of the supraspinatus and infraspinatus muscles with lateral abduction of the shoulder joint when walking. Electromyography revealed decreased innervation to the supraspinatus and infraspinatus muscles consistent with suprascapular neuropathy.
The suprascapular nerve was surgically decompressed by removing the entrapping hematoma and periosteum and performing a notch resection of the scapula; dexamethasone (40 mg) was administered prior to closure. The bull was discharged 5 days after surgery; no lameness was evident at the time of discharge. The owner was instructed to restrict the bull to a stall or small pen for 6 weeks. Four months after surgery, the muscle atrophy had substantially improved, and the bull returned to bucking.
Findings suggested that suprascapular neuropathy can develop in bulls secondary to injury and that suprascapular nerve decompression may improve nerve function, muscle atrophy, and gait.
一头3岁、体重639千克（1406磅）的美国斗牛，因右前肢跛行4天前来检查。跛行始于一次牛仔竞技表演中，这头牛在从斜槽出来时右肩部受伤。
右肩部有一个10×10厘米的软组织肿胀。超声检查显示，肩胛冈、肱二头肌滑囊、肱二头肌肌腱和肱骨大结节的轮廓未见异常；肿胀似乎是肩胛骨远端上方的血肿。检查四肢远端时，未发现外部伤口、可触及的关节积液或肿胀。这头牛行走时出现冈上肌和冈下肌萎缩，肩关节外展。肌电图显示，冈上肌和冈下肌的神经支配减少，符合肩胛上神经病变。
通过清除压迫性血肿和骨膜，并对肩胛骨进行切迹切除术，对肩胛上神经进行手术减压；在缝合前给予地塞米松（40毫克）。术后5天这头牛出院；出院时无跛行迹象。主人被告知将这头牛限制在畜栏或小围栏内6周。术后4个月，肌肉萎缩明显改善，这头牛恢复了斗牛活动。
研究结果表明，公牛继发于损伤后可能会发生肩胛上神经病变，肩胛上神经减压可能会改善神经功能、肌肉萎缩和步态。
