Two-Stage Glenohumeral Fusion for the Paralytic Shoulder

Abstract

BackgroundShoulder fusion after nerve injury can improve overall arm function, however high revision and low patient satisfaction rates have been described. The purpose of this study is to describe a two-stage shoulder fusion, first pinning in a position of function and then converting to a shoulder fusion. Our hypothesis is that temporary pinning improves overall satisfaction after shoulder fusion in comparison to satisfaction reported in the literature. MethodsA retrospective review was performed for patients receiving two-stage shoulder fusion between 2020 and 2023. Patient demographics and clinical outcomes were recorded. Univariate statistics were performed to compare pre- and postoperative values. ResultsEighteen patients with an average age of 47 +/- 17.3 years and average follow-up of 23.7 +/- 4.5 months were included. Preoperative diagnoses included brachial plexus injury (n=13; 72%), late presentation obstetric brachial plexus injury (n=2; 11%), traumatic brain injury (n=1; 14.2%), cervical spinal cord injury (n=1; 14.2%) and iatrogenic axillary nerve injury with advanced arthritis (n=1;14.2%). Twelve (67%) patients received unilateral shoulder fusion 2.7 +/- 1.9 days after their initial pinning. Six patients (28.6%) did not receive a second stage fusion. Reasons for not continuing with fusion were attributed to perceived hand function and arm position. Three patients received two shoulder pinnings prior to their fusion to adjust the fusion position to accommodate more internal rotation. After fusion, both SSV (5.2 +/- 5.5% versus 71.6 +/- 10.4%; p<0.001) and pain (2.3 ± 4.0 vs 0.5 ± 0.71; p=0.56) improved. Forward elevation (5 +/- 12 versus 108 +/-35; p=0.01), abduction (10 +/- 15 versus 78 +/-9; p<0.001)), and external rotation (5 +/- 12 versus 22 +/- 17; p=0.26) all improved postoperatively while internal rotation remained limited (1.3 +/- 0.9 versus 1.2 +/- 0.5; p=0.84). Time to union was 15.4 +/- 15.4 weeks confirmed with CT scan. There was one (5.5%) reoperation for non-union, and patient satisfaction was 92% (n=11/12). ConclusionShoulder fusion after neurologic injury provides improved function and patient outcomes, however some patients may be unsatisfied with their new arm position. Percutaneous pinning prior to fusion is tolerated and allows patients to trial potential fusion positions. This method may improve patient satisfaction and avoid excess morbidity in those that would not be satisfied with a shoulder fusion.