Short-stem hip arthroplasty in Australia and the Netherlands: a comparison of 12,680 cases between the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) and the Dutch Arthroplasty Register (LROI).

Background And Purpose: We compared the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) and the Dutch Arthroplasty Register (LROI) regarding patient, prosthesis, and procedure characteristics as well as revision rates for uncemented short-stem total hip arthroplasties (THAs).

Patients And Methods: All THAs with an uncemented short-stemmed femoral component performed between 2009 and 2021 were included from the AOANJRR (n = 9,328) and the LROI (n = 3,352). Kaplan-Meier survival analyses and multivariable Schemper's weighted Cox regression analyses with data from 2009-2021 and 2015-2021 were performed with overall revision as endpoint.

Results: In Australia, the proportion of male patients (51% vs. 40%), patients with ASA III-IV score (30% vs. 3.7%), BMI ≥ 30.0 (39% vs. 19%), and femoral heads of 36 mm (58% vs. 20%) were higher than in the Netherlands. Short-stem THAs in Australia and the Netherlands had comparable 10-year revision rates (3.4%, 95% confidence interval [CI] 2.9-4.0 vs. 4.8%, CI 3.7-6.3). Multivariable Cox regression analyses with data from 2009-2021 showed a higher risk for revision of short-stem THAs performed in the Netherlands (HR 1.8, CI 1.1-2.8), whereas the risk for revision was comparable (HR 0.9, CI 0.5-1.7) when adjusted for more potential confounders using data from 2015-2021.

Conclusion: Short-stem THAs in Australia and the Netherlands have similar crude and adjusted revision rates, which are acceptable at 10 years of follow-up.