Elevated risk of medical and implant-related complications in patients with hypothyroidism after total shoulder arthroplasty: a 1:1 propensity matched cohort analysis.

BACKGROUND

There is currently limited work that evaluates the effect of comorbid hypothyroidism on complications and outcomes following total shoulder arthroplasty (TSA). This study aims to evaluate the impact of hypothyroidism on 90-day medical complications as well as 2-year implant related complications and revision rates following TSA.

METHODS

This retrospective database analysis evaluated patients who underwent TSA between October 1, 2015, and March 9, 2022. Patients with 2-year follow-up were categorized based on the presence of preoperative hypothyroidism within three months before TSA versus euthyroid status, resulting in 7716 hypothyroid and 46,568 euthyroid patients. A 1:1 propensity score matching was performed, adjusting for age, gender, race, ethnicity, and comorbid conditions (diabetes, hypertension, chronic kidney disease, tobacco use, obesity, heart failure, and liver diseases). Postoperative complications were assessed at 90 days, and implant-related complications were evaluated at two years. A Bonferroni correction was applied to account for multiple comparisons.

RESULTS

After matching, 7716 matched patients were included in each cohort. Hypothyroid patients had significantly higher risks of sepsis, infection, pulmonary embolism, stroke, and hospital readmission (all P < .0001), as well as higher rates of anemia, pneumonia, renal failure, and blood transfusion requirements (all P < .0001) within 90 days postoperatively. Myocardial infarction did not meet the significance threshold (P = .005). At 2 years, these patients had elevated rates of periprosthetic fractures, prosthetic joint infection, dislocation, revision surgeries, and mechanical loosening (all P < .0001).

CONCLUSION

Hypothyroidism is associated with an increased risk of 90-day medical complications and 2-year implant-related complications following shoulder arthroplasty. Further investigation into these findings and potential for perioperative medical optimization is indicated.