Total Joint Arthroplasty in Patients With Achondroplasia: Comparison of 90-Day Adverse Events and 5-Year Implant Survival

BACKGROUND: Achondroplasia is the most common skeletal dysplasia, and total joint arthroplasty of the hip and/or knee in this patient population may present unique challenges. METHODS: All patients undergoing primary total hip or total knee arthroplasty (THA or TKA) for osteoarthritis in the 2010-2019 PearlDiver Mariner administrative database with least 90 days of postoperative follow-up were identified. Those with achondroplasia were matched 1:10 to patients without achondroplasia based on age, sex, and medical comorbidities. Ninety-day adverse events were assessed and compared using multivariate logistic regression. Five-year implant survival was determined and compared with Kaplan-Meier implant survival curves. Significance was set at P < .05. RESULTS: For THA, 150 patients with achondroplasia were matched to 1484 patients without and had significantly higher 90 days odds of surgical site infection (odds ratio [OR] = 3.49, P = .005) and readmission (OR = 2.35, P = .016). For TKA, 285 patients with achondroplasia were matched to 2828 without and had higher odds of aggregated any adverse event (OR = 1.52, P = .006) and transfusion (OR = 2.31, P < .001). Rates of the other studied adverse events were not significant for either set of the analyses. At 5 years, implant survival for those with and without achondroplasia was not different for those undergoing THA (P = .321) or TKA (P = .910). CONCLUSIONS: The present study represents the largest cohort of patients with achondroplasia undergoing total joint arthroplasty to date. Although several short-term adverse events had greater odds for those with achondroplasia, 5-year survival was not different for those with or without achondroplasia after THA or TKA, supporting confidence in longer term implant success.