SUMMARY
Introduction. Developmental dysplasia of the hip (DDH) is a severe orthopedic pathology characterized by joint malformation, pain, deformity, and functional limitation from early ages. Total hip arthroplasty (THA) is considered the final treatment option for these patients. However, the impact of dislocation severity—according to the Crowe classification—on postoperative outcomes remains controversial. Objective. This study aims to comparatively analyze postoperative joint range of motion (ROM), functional, clinical, and pain-related outcomes after THA in Crowe type I–III hips and to evaluate the statistical impact of dislocation type on these outcomes. Material and methods. Between 2018 and 2020, 129 patients (135 hips) with dysplastic coxarthrosis underwent THA using the same surgical technique. Patients were divided into three groups according to Crowe types I–III. Preoperative and 6–12 months postoperative evaluations were performed using goniometry, Merle d’Aubigné–Postel (MAP), Harris Hip Score, WOMAC, Visual Analog Scale (VAS), and SF-36. Statistical analysis included Wilcoxon Signed-Ranks, Kruskal–Wallis, Bonferroni correction, and Pearson’s chi-square tests. Results. All Crowe groups showed statistically significant improvement in ROM, functional scores, and health indicators after surgery (p<0.001). The most notable intergroup differences were observed in flexion angle (Crowe III > II), preoperative deformity (Crowe I > II ≈ III), and limb length discrepancy (Crowe I < II < III). Most other parameters demonstrated comparable postoperative outcomes across groups. Conclusion. THA yields successful functional and clinical outcomes in dysplastic hips regardless of Crowe dislocation type. Although higher dislocation degrees are associated with greater preoperative deformity and limb length discrepancy, these differences can be effectively corrected intraoperatively with appropriate surgical technique.
Keywords: developmental dysplasia of the hip, Crowe classification, total hip arthroplasty, range of motion, functional outcome, pain

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