Summary

Patients with multiple shoulder dislocations before stabilization surgery are at a significantly higher risk of requiring revision surgery and postoperative closed reduction compared to those with a single dislocation, suggesting the importance of earlier surgical intervention.

Abstract

Introduction

Shoulder instability is known to lead to increased recurrence with each dislocation prior to stabilization procedures. The extent to which multiple shoulder dislocations increase the risk of recurrent instability following surgery in a large population is not known.

Methods

A large insurance database was queried for patients with shoulder stabilization for surgery between 2010-2018. The study population was stratified by single dislocation versus multiple dislocations before surgery. Groups were matched by surgery type, Charlson Comorbidity Index, age, and gender. The primary outcome was revision shoulder instability surgery; other outcomes included postoperative closed reduction of the shoulder, ED visits, readmissions, and medical complications.

Results

Baseline demographics were similar between groups (N=161 per group). Overall, 21 patients (13.0%) with a single dislocation and 47 patients (29.2%) with multiple dislocations had subsequent revision surgery (OR-2.75, P=0.0006). Twelve patients (7.5%) with a single dislocation and 42 patients (26.1%) with multiple dislocations required a closed reduction postoperatively (OR = 4.38, P<0.0001). An increasing number of dislocations was associated with greater risk of postoperative dislocation requiring closed reduction (OR = 1.05, 95% CI 1.04-1.07, P<0.0001) and increased risk of revision (OR = 1.03, 95% CI 1.02-1.05, P<0.0001). There were no differences in rates of manipulation under anesthesia (P=0.62), readmission (P=0.80), or complications (P>0.99). Significant predictors of revision for instability included open Latarjet procedure (adj-OR=10.39, P=0.03), arthroscopic capsulorrhaphy (adj-OR=7.53, P=0.03), and history of multiple shoulder dislocations (adj-OR=2.92, P=0.0003).

Conclusions

Compared to patients with a single shoulder dislocation, those with multiple dislocations are twice as likely to require revision surgery and 3 times as likely to require a postoperative closed reduction. An increasing number of dislocations prior to a stabilization procedure is associated with a greater risk of postoperative instability requiring closed reduction or revision. Overall, patients undergoing shoulder stabilization may benefit from earlier surgical intervention.