Comparison of minimally invasive and standard posterior approach in total hip arthroplasty for Crowe type 2 dysplastic coxarthrosis: clinical, radiographic, and functional outcomes.

Introduction: The debate continues regarding the advantages of minimally invasive techniques in total hip arthroplasty (THA) compared to standard approaches. However, data on the use of minimally invasive approaches in dysplastic hips are limited. This study aims to compare the clinical, radiological, and functional outcomes of minimally invasive surgery (MIS) and standard surgery (SS) techniques in THA for Crowe type 2 dysplastic hips.

Materials and methods: This retrospective, single-center study included 48 patients with Crowe type 2 dysplastic coxarthrosis who underwent primary THA between November 2022 and January 2024. Patients were divided into two groups based on the incision technique: MIS (n = 22) and SS (n = 23). Demographic data, intraoperative variables, and complications were recorded. Clinical evaluation included the Harris Hip Score (HHS), Berg Balance Scale (BBS), and Joint Position Sense (JPS) test at 3 months and 1-year follow-up. Radiological assessment involved component positioning, femoral offset, and leg length discrepancy.

Results: The MIS group demonstrated significantly shorter incision length (8.5 cm vs. 14 cm; p < 0.001), reduced intraoperative blood loss (223.9 ml vs. 281.7 ml; p < 0.05), and shorter operative time (49.9 min vs. 58.8 min; p < 0.05) compared to the SS group. Both groups showed significant improvement in HHS at 3 months and 1-year follow-up. Early postoperative HHS, BBS, and JPS scores were significantly better in the MIS group at 3 months (p < 0.05), while no significant differences were observed between groups at 1-year follow-up. Radiological parameters, including component positioning and leg length discrepancy, were similar between groups, except for femoral offset, which was higher in the MIS group. No major complications, including dislocation, infection, or nerve injury, were observed in either group.

Conclusions: The MIS posterior approach in THA for Crowe type 2 dysplastic hips is a safe and effective technique providing advantages of reduced blood loss, shorter operative time, and smaller incision without component malposition or increased complication rates. Although early functional outcomes were better in the MIS group, the 1-year results were similar between the two techniques.