Complications associated with postoperative stiffness following primary anatomic and reverse total shoulder arthroplasty

Abstract

Background

Shoulder stiffness following both primary anatomic and reverse total shoulder arthroplasty (TSA) is a potential complication that is likely underreported. The deleterious effects of postoperative stiffness following TSA and the burden placed on both the patient and the healthcare system have not been well studied. The purpose of this study is to determine the incidence of postoperative stiffness following primary TSA and analyze the effect it has on short-term outcomes up to 180 days following primary TSA.

Methods

This was a retrospective, comparative cohort study. The Nationwide Readmissions Database was queried from 2010 to 2020 for patients who had undergone primary TSA using International Classification of Diseases Clinical Modification and Procedure Coding System codes. Patients were then separated into stiff and non-stiff cohorts. A one-to-one match was performed based on age, sex, and the Charlson comorbidity index. Statistical analyses included chi-square, sample t-tests, logistic, and linear regression.

Results

A total of 7792 subjects were included in the study. The overall incidence of postoperative stiffness was 1.8%. Patients with stiffness following primary TSA were 57% more likely to be readmitted within 180 days (odds ratio [OR] = 1.57) and had increased hospital costs by over $5000 (P < .001), but mortality rates were not increased. However, the odds of experiencing any medical complication or revision decreased by 52% and 76%, respectively, in the stiff group (OR = 0.48, and OR = 0.24, respectively). Postoperative stiffness was inversely predictive of prosthetic dislocation (OR = 0.03), loosening (OR = 0.03), and periprosthetic fracture (OR = 0.04).

Conclusion

The incidence of postoperative stiffness following primary TSA was low at 1.8 %. These patients were found to be at increased risk for readmission within 180 days and incurred significantly higher hospital costs compared to the non-stiff cohort. However, postoperative stiffness did not increase the odds of experiencing increased medical complications, mechanical complications, mortality, or revision at 180 days. This information can help guide surgeons in discussion with and management of patients who develop stiffness following primary TSA.