Summary

Timing of dislocation affects the need for revision surgery after total shoulder arthroplasty

Abstract

Background

Total shoulder arthroplasty (TSA), including both reverse total shoulder arthroplasty (rTSA) and anatomic total shoulder arthroplasty (aTSA), generally yields excellent outcomes, however instability remains a common and challenging complication, often leading to revision surgery. Previous studies investigated the effectiveness of closed reduction for dislocations occurring within the first 90 days post-surgery. The impact of dislocation timing on the risk of revision surgery remains unclear. Therefore, this study aims to evaluate and compare the risk of revision surgery for early versus late dislocation, using a 90-day threshold.

Materials And Methods

Using the TriNetX Research Network database, this retrospective comparative study included patients with dislocation after TSA. Two cohorts were determined based on timing of dislocation within 90 days and after 90 days following TSA. Propensity score matching was conducted, utilizing 1:1 nearest matching technique to create balanced cohorts based on age, gender and comorbidities identified in the univariate analysis. After matching, the study assessed the risk of revision surgery and recurrent dislocations. The risk ratio (RR) and 95% confidence interval (CI) were calculated for each matched cohort.

Results

The study included a total of 27,932 patients who underwent TSA, with a mean age of 69.4 ± 9.3 years. The majority of patients in both cohorts were female (p=< 0.0001). After matching, the risk of revision surgery was significantly higher in late dislocation group (>90 days) (p=< 0.0001). Additionally, the risk of recurrent dislocations was significantly higher in the late dislocation group (>90 days) (p= 0.0066)

Conclusion

Dislocation occurring more than 90 days following TSA is associated with a higher likelihood of requiring revision surgery and experiencing recurrent dislocations. These findings highlight the importance of considering the timing of dislocation in the management and treatment strategies for TSA patients.