Total hip arthroplasty outcomes in Ehlers-Danlos patients: data from the Statewide Planning and Research Cooperative System

Introduction: Ehlers-Danlos syndromes (EDS) are genetic connective tissue disorders affecting multiple organ systems that frequently result in connective tissue hyperlaxity and early osteoarthritis. Short- and long-term outcomes after primary total hip arthroplasty (THA) in this patient population remain poorly characterised. The primary purpose of this study is to compare postoperative outcomes and survivorship after primary THA in patients with and without EDS. Methods: The New York Statewide Planning and Research Cooperative System (SPARCS) database was queried for all patients undergoing primary elective THA between September 2009 and December 2020. Patients with EDS were identified using ICD9 and ICD10 diagnosis codes. Given the relatively low incidence of EDS in this patient population, the cohort was propensity-matched 1:10 to patients without diagnosis of EDS based on demographics characteristics and medical comorbidities as measured by the Elixhauser Comorbidity Index. Results: A total of 66 THA patients with and 660 without EDS were included in each group after 1:10 propensity-matching. There were no significant differences in baseline characteristics or THA indications. Early postoperative outcomes such as length of hospital stay and discharge disposition were similar. Emergency Room visits and inpatient readmission rates at 3 months postoperatively did not significantly differ between groups. Patients with EDS had a higher overall revision rate compared to those without (15.0% vs. 3.2%, p < 0.001). Revision free survival after primary THA in patients with EDS was significantly lower than those without EDS at 9-year follow-up. Cox proportional hazard regression demonstrated EDS patients had 7-times higher risk of revision (hazard ratio [HR] 7.43; 95% CI, 3.46-16.00; p < 0.001). Lastly, revision due to instability insignificantly trended higher in the EDS cohort (HR 2.29; 95% CI, 0.95-5.49; p = 0.063). Conclusions: EDS patients undergoing primary THA have increased rate of all cause revision and demonstrate decreased revision free survival compared to non-EDS THA patients.