These authors report on the incidence of distal peripheral neuropathy requiring surgical intervention following shoulder arthroplasty. Distal peripheral neuropathy was defined as symptoms or diagnostic testing consistent with cubital tunnel or carpal tunnel syndrome.
1,387 total shoulder arthroplasties were included in this study. 16 patients (1.2%) underwent surgery for ipsilateral peripheral neuropathy while 6 patients (0.4%) underwent surgery for contralateral peripheral neuropathy.
Comment: This study may have underestimated the incidence of post operative neuropathy for several reasons: (1) Patients were included in the series only if they had primary surgical intervention for ipsilateral or contralateral peripheral neuropathy following primary anatomic or reverse total shoulder arthroplasty. (2) Patients were not systematically examined for evidence of neurological abnormalities. (3) Patients with symptoms of peripheral neuropathy, but who did not undergo surgery for the neuropathy were not considered. (4) Not all peripheral neuropathies present as symptoms of cubital or carpal tunnel syndromes.
The brachial plexus is at risk during shoulder arthroplasty because of (1) nerve laceration, (2) nerve compression from retractors, (3) nerve traction, (4) arm lengthening, and (5) neck positioning during the surgery.
In this series, it appears that brachial plexus block anesthesia was used. This intervention carries an additional risk of peripheral nerve injury as revealed in this study, The types and severity of complications associated with interscalene brachial plexus block anesthesia: local and national evidence. Here is the abstract from that article:
"Interscalene brachial plexus block is a commonly used anesthetic. However, substantial complications can be associated with its use. Our study included 15 years of data from a local medical center and 3 decades of records from the national American Society of Anesthesiology Closed Claims Project. The hospital had 27 peripheral neurologic injuries, 3 central nervous system complications, 6 respiratory complications, and 5 cardiovascular complications. Of these complications, 14 were still present at the most recent follow-up, some causing major compromise of the patient's comfort and function. All central blocks, local toxicities, and respiratory complications resolved. In the hospital series, more experienced anesthesiologists tended to have lower complication rates. The American Society of Anesthesiology Closed Claims database had 20 peripheral neurologic injuries, 10 respiratory complications, 5 central nervous system complications, 4 deaths, 2 emotional disturbances, and 1 other unknown event. Of the complications, 19 were described as permanent. Interscalene brachial plexus block can be accompanied by substantial and disabling complications, especially when administered by less experienced anesthesiologists."