Nagda Sameer H, Rogers Kenneth J, Sestokas Anthony K, Getz Charles L, Ramsey Matthew L, Glaser David L, Williams Gerald R
Division of Orthopaedic Surgery, University of Pennsylvania School of Medicine, Philadelphia, USA.
J Shoulder Elbow Surg. 2007 May-Jun;16(3 Suppl):S2-8. doi: 10.1016/j.jse.2006.01.016. Epub 2006 Jul 26.
The incidence of neurologic injury after shoulder arthroplasty has been reported to be 1% to 4%. However, the true incidence may be higher, because injury is identified only clinically and examination of the post-arthroplasty shoulder is difficult. This study used intraoperative nerve monitoring to identify the incidence, pattern, and predisposing factors for nerve injury during shoulder arthroplasty. Continuous intraoperative monitoring of the brachial plexus was performed in 30 consecutive patients undergoing shoulder arthroplasty. Impending intraoperative compromise of nerve function was signaled by sustained neurotonic electromyographic activity or greater than 50% amplitude attenuation of transcranial electrical motor evoked potentials (or both). Arm and retractor positions were recorded and adjusted to relieve tension. Patients with intraoperative nerve alerts underwent diagnostic electromyography at least 4 weeks postoperatively. Of the patients, 17 (56.7%) had 30 episodes of nerve dysfunction (ie, nerve alerts) during surgery. None of these 30 nerve alerts returned to baseline with retractor removal alone. Of the 30 alerts, 23 (76.7%) returned to baseline after repositioning of the arm into a neutral position. Postoperative electromyography results were positive in 4 of 7 patients (57.1%) who did not have a return to baseline transcranial electrical MEPs intraoperatively and in 1 of 10 (10%) whose nerve function did return to baseline. In all cases of positive postoperative electromyographic results, the pattern of nerve involvement matched the pattern of intraoperative nerve dysfunction. The affected nerves included the following: combined (ie, mixed plexopathy) (46.7%), musculocutaneous (20%), axillary (16.7%), ulnar (10%), and radial (6.7%). Prior shoulder surgery and passive external rotation of less than 10 degrees were associated with an increased incidence of nerve dysfunction (P < .05). The incidence of nerve injury during shoulder arthroplasty is likely greater than reported. Positioning of the arm at the extremes of motion should be minimized. Patients with decreased motion (<10 degrees passive external rotation with the arm at the side) and a history of prior open shoulder surgery are at higher risk for nerve injury and should be counseled on the increased risk. This patient population may also be considered for routine nerve monitoring.
据报道，肩关节置换术后神经损伤的发生率为1%至4%。然而，实际发生率可能更高，因为损伤仅通过临床诊断，且术后肩关节检查困难。本研究采用术中神经监测来确定肩关节置换术中神经损伤的发生率、类型及易感因素。对连续30例接受肩关节置换术的患者进行了术中臂丛神经连续监测。术中神经功能即将受损的信号为持续的神经紧张性肌电图活动或经颅电运动诱发电位幅度衰减超过50%（或两者皆有）。记录并调整手臂和牵开器的位置以缓解张力。术中出现神经警报的患者在术后至少4周接受诊断性肌电图检查。在这些患者中，17例（56.7%）在手术期间出现30次神经功能障碍发作（即神经警报）。仅移除牵开器后，这其中30次神经警报均未恢复至基线水平。在这30次警报中，23次（76.7%）在将手臂重新置于中立位后恢复至基线水平。术中经颅电运动诱发电位未恢复至基线水平的7例患者中，4例（57.1%）术后肌电图结果呈阳性；神经功能恢复至基线水平的10例患者中，1例（10%）术后肌电图结果呈阳性。在所有术后肌电图结果呈阳性的病例中，神经受累类型与术中神经功能障碍类型相符。受累神经包括以下几种：混合型（即混合性神经病变）（46.7%）、肌皮神经（20%）、腋神经（16.7%）、尺神经（10%）和桡神经（6.7%）。既往肩部手术及被动外旋小于10度与神经功能障碍发生率增加相关（P<0.05）。肩关节置换术中神经损伤的发生率可能高于报道。应尽量减少手臂处于极端运动位置的情况。运动减少（手臂置于身体一侧时被动外旋<10度）且有既往开放性肩部手术史的患者神经损伤风险较高，应告知其风险增加。对于这一患者群体，也可考虑进行常规神经监测。
