Greater Auricular Nerve Palsy After Arthroscopic Anterior-Inferior and Posterior-Inferior Labral Tear Repair Using Beach-Chair Positioning and a Standard Universal Headrest

Discussion

The most important finding in this case is the greater auricular nerve palsy that occurred after arthroscopic anterior-inferior and posterior-inferior labral repairs in beach-chair positioning. This greater auricular nerve palsy was the first encountered by Dr. Foad, who over 17 years in a primarily shoulder practice setting has used beach-chair positioning exclusively. Previous reports have described a palsy occurring after arthroscopic shoulder surgery using beach-chair positioning and a horseshoe headrest.^7,8 Ng and Page⁷ discontinued and recommended against use of this headrest because of the complications of the palsy, and Park and Kim⁸ recommended a headrest redesign. We think the present case report is the first to describe a greater auricular nerve palsy that occurred after arthroscopic surgery using a standard universal headrest, which theoretically should prevent compression of the greater auricular nerve. Increased awareness of the possibility of greater auricular nerve palsy, even when proper precautions are taken,¹ is therefore warranted.

Based on the location of our patient’s palsy, we think his paralysis was most likely the result of nerve compression by the headrest during the shoulder surgery. Other factors, though unlikely, may have played a role. These include operative time (increases duration of nerve compression) and head positioning. However, 122 minutes is not unusually long for a patient’s head to be in this position during a procedure, and over the past 10 years the same anesthesiologist, head nurse, and circulating nurse have routinely used the same beach-chair positioning and headrest for Dr. Foad’s patients. Second, the postoperative interscalene block theoretically could have caused the palsy, but we think this is unlikely, as the block is placed lower on the neck, at the C6 level, and the greater auricular nerve branches off the C2–C3 spinal nerves. As described by Rains and colleagues,⁹ other authors have reported transient neuropathies to the brachial plexus, which originates in the C5–C8 region, but not to the greater auricular nerve. Last, it cannot be ruled out that a variant of the greater auricular nerve could have played a role, given the variation in the greater auricular nerve.^10,11 However, Brennan and colleagues¹⁰ reported that 2 of 25 neck dissections involved a variant in which the anterior division of the greater auricular nerve passed into the submandibular triangle and joined the mandibular region of the facial nerve. Stimulation of this nerve resulted in activity of the depressor of the lower lip, which was not the location of our patient’s palsy. In addition, our patient’s symptoms followed a classic nerve distribution of the greater auricular nerve (Figures 1, 4), which would seem to decrease the likelihood that a variant was the source of the palsy.

The superficial nature of the greater auricular nerve, which runs roughly parallel with the sternocleidomastoid muscle and innervates much of the superficial region of the skin over the mastoid, parotid gland, and mandible,^5-7 theoretically places the nerve at risk for compressive forces from the headrest during arthroscopic shoulder surgery. Skyhar and colleagues³ first described beach-chair positioning as an alternative to lateral decubitus positioning, which had been reported to result in neurologic injury in about 10% of surgical cases.⁹ The theoretical advantages of beach-chair positioning are lack of traction needed and ease of setup, which would therefore decrease the possibility of neuropathy.^1,3 However, as seen in this and other case reports,^7,8 greater auricular nerve neuropathy should still be considered a possible complication, even when using beach-chair positioning.

Besides neuropathy after arthroscopic shoulder surgery, as described in previous case reports^7,8 and in the present report, greater auricular nerve injury has been described as arising from other stimuli. Greater auricular nerve injury has arisen after perineural tumor metastasis,⁶ neuroma of greater auricular nerve after endolympathic shunt surgery,¹² internal fixation of mandibular condyle,¹³ and carotid endarterectomy.^14,15 Given the superficial nature of the greater auricular nerve, it may not be all that surprising that a palsy could also develop after headrest compression during arthroscopic shoulder surgery.

This case report brings to light a possible complication of greater auricular nerve palsy during arthroscopic shoulder surgery using beach-chair positioning and a standard universal headrest. Studies should now investigate whether greater auricular nerve palsy is more common than realized, especially with regard to specific headrests in beach-chair positioning. For now, though, Dr. Foad’s intention is not to change to a different headrest or discontinue beach-chair positioning but to draw attention to this rare complication. Additional attention should be given to the location of the headrest in relation to the greater auricular nerve, especially in cases in which operative time may be longer.