Axillary nerve palsy incidence after total shoulder arthroplasty with and without neuromuscular blockade

Axillary nerve palsy is a rare but significant complication of shoulder arthroplasty. The axillary nerve lies just beneath the inferior glenoid, increasing susceptibility to traction and compression injures during surgery. Neuromuscular blocking agents are commonly used to facilitate exposure and dissection but may reduce the surgeon's ability to perceive excessive traction or tension on the nerve. The aims of this study are twofold, to (1) determine whether intraoperative paralytic use is associated with post-operative axillary nerve palsy and (2) assess its relationship with operative time.

A retrospective study was conducted of patients that underwent anatomic total shoulder arthroplasty and reverse total shoulder arthroplasty between 2015 and 2024 at a single health-care center. Exclusion criteria included hemiarthroplasty, prior ipsilateral open shoulder surgery, pre-existing axillary nerve deficits, and lack of documented three months axillary nerve examination. Of 2,303 eligible patients, 397 were excluded, leaving 1906 patient for primary analysis. Collected variables included demographics, comorbidities, American Society of Anesthesiologist classification, and paralytic use. Outcomes assessed were post-operative axillary nerve palsy at three months and operative duration.

Among 1,906 patients included in the primary analysis, 1,398 (73.3%) received intraoperative paralytics. Post-operative axillary nerve palsy occurred in 17 patients (0.9%). Among patients who did not receive paralytics, 0.4%, developed axillary nerve palsy, compared to 1.1% who received paralytics (P = .268). On multivariable analysis adjusting for age, sex, and procedure type, intraoperative paralytic use was not independently associated with axillary nerve palsy (adjusted odds ratio 2.58, 95% confidence interval [CI] 0.59-11.39; P = .210), while male sex was independently associated with higher odds of palsy (adjusted odds ratio 3.07, 95% CI 1.11-8.46; P = .030). In adjusted linear regression analysis, intraoperative paralytic use was associated with significantly shorter operative time (β -18.3 minutes; 95% CI -22.2 to -14.4; P < .001). Overall, 172 patients (7.5%) experienced complications at 90 days, with reoperation and revision rates of 1.1% and 0.5%, respectively.

In this large retrospective study, intraoperative paralytic use was not associated with a higher risk of axillary nerve palsy but was linked to a significant 18.3 minutes reduction in operative time. These findings suggest that paralytic use may enhance surgical efficiency without increasing post-operative nerve injury. However, given the low incidence of palsy and the retrospective nature design, further studies are warranted to confirm these associations and their clinical relevance.