Anterior-inferior and posterior-inferior labral tears are common injuries treated with arthroscopic surgery1 typically performed with beach-chair2,3 or lateral decubitus1,2 positioning and variable headrest positioning. Iatrogenic nerve damage that occurs after arthroscopic shoulder surgery—including damage to the suprascapular, axillary, musculocutaneous, subscapular, and spinal accessory nerves—has recently been reported to be more common than previously recognized.2,4
Although iatrogenic nerve injuries are in general being recognized,1,2,4 reports of greater auricular nerve injuries are limited. The greater auricular nerve is a superficial cutaneous nerve that arises from the cervical plexus at the C2 and C3 spinal nerves, obliquely crosses the sternocleidomastoid muscle, and splits into anterior and posterior portions that innervate the skin over the mastoid process and parotid gland.5,6 In particular, as illustrated by Ginsberg and Eicher6 (Figure 1), its superficial anatomy lies very near where a headrest is positioned during arthroscopic surgery, and increased pressure on the nerve throughout arthroscopic shoulder surgery may lead to neurapraxia.6,7 In 2 case series, authors reported on a total of 5 patients who had greater auricular nerve palsy after uncomplicated shoulder surgery using beach-chair positioning and a horseshoe headrest.7,8 The authors attributed these palsies to the horseshoe headrest, which they believed was compressing the greater auricular nerve during the entire surgery.7,8 However, standard universal headrests, which are thought to distribute pressures that would theoretically place the greater auricular nerve at risk for palsy, previously had not been described as contributing to palsy of the greater auricular nerve.
In this article, we report on a case of greater auricular nerve palsy that occurred after the patient’s anterior-inferior and posterior-inferior labral tear was arthroscopically repaired using beach-chair positioning and a standard universal headrest. The patient provided written informed consent for print and electronic publication of this case report.
Case Report
An 18-year-old right-hand–dominant high school American football player was referred for orthopedic evaluation of left chronic glenohumeral instability after 6 months of physical therapy. Physical examination revealed a positive apprehension test with the shoulder abducted and externally rotated at 90° and a positive relocation test. The patient complained of pain and instability when his arm was placed in a cross-chest adducted position and a posteroinferiorly directed axial load was applied. Magnetic resonance arthrogram showed an anterior-inferior labral Bankart tear with a small Hill-Sachs lesion to the humeral head but did not clearly reveal the posterior-inferior labral tear. Because of persistent left shoulder instability with most overhead activities and continued pain, the patient decided to undergo left shoulder arthroscopic Bankart repair with inferior capsular shift and posterior-inferior labral repair with capsulorraphy. He had no significant past medical history or known drug allergies.
The patient was placed in the standard beach-chair position: upright at 45° to the floor, hips flexed at 60°, knees flexed at 30°.1 Pneumatic compression devices were placed on his lower extremities. His head was secured in neutral position to a standard universal headrest (model A-90026; Allen Medical Systems, Acton, Massachusetts) (Figures 2, 3). Care was taken to protect the deep neurovascular structures and bony prominences throughout. The patient was in this position for 122 minutes of the operation, from positioning and draping to wound closure and dressing application. Before draping, the anesthesiologist, head nurse, and circulating nurse ensured that head and neck were in neutral position. The anesthesiologist monitored positioning throughout the perioperative period to ensure head and neck were in neutral, and the head did not need to be repositioned during surgery. Standard preoperative intravenous antibiotics were given.
General anesthesia and postoperative interscalene block were used. Standard preparation and draping were performed. Three standard arthroscopic portal incisions were used: posterior, anterior, and anterosuperolateral. Findings included extensive labral pathology, small bony Hill-Sachs lesion to humeral head, small bony anterior glenoid deficiency, and deficient anterior-inferior and posterior-inferior labral remnant. These were repaired arthroscopically in a standard fashion using bioabsorbable suture anchors. There were no arthroscopic complications. After surgery, a standard well-fitted shoulder immobilizer was placed. The anesthesiologist provided interscalene regional analgesia (15 mL of bupivacaine 0.5%) in the recovery area after surgery.
Postoperative neurovascular examination in the recovery room revealed no discomfort. The patient was discharged the same day. At a scheduled 1-week follow-up, he complained of numbness and dysesthesia on the left side of the greater auricular nerve distribution. A diagnosis of greater auricular nerve palsy was made by physical examination; the symptoms were along the classic greater auricular nerve distribution affecting the lower face and ear (Figure 4). The patient had no pain, skin lesions, or soft-tissue swelling. Otolaryngology confirmed the diagnosis and recommended observation-only treatment of symptoms. Symptoms lessened over the next 3 months, and the altered sensation resolved without deficit by 6 months. In addition, by 6 months the patient had returned to full activities (including collision sports) pain-free and with normal left shoulder function. Because symptoms continued to improve, the patient was followed with clinical observation, and a formal work-up was not necessary.