Short to mid-term functional outcomes and early blood loss of THA in patients with developmental hip dysplasia after childhood open surgery versus primary osteoarthritis.

INTRODUCTION

This study aimed to compare short to mid-term functional outcomes and perioperative blood loss in patients undergoing total hip arthroplasty (THA) due to primary osteoarthritis versus those with a history of childhood open surgery for developmental dysplasia of the hip (DDH).

MATERIALS AND

METHODS

This retrospective study included 216 patients who underwent THA between 2019 and 2024. Group 1 consisted of 72 patients with a history of open surgery for developmental dysplasia of the hip, and Group 2 included 144 patients with primary osteoarthritis matched at a 1:2 ratio based on body mass index (caliper width ± 2 kg/m²). Hemoglobin and hematocrit levels were recorded preoperatively and on postoperative days 0, 1, and 2. Perioperative trends were analyzed using linear mixed-effects models. Functional outcomes (Harris Hip Score-HHS, Oxford Hip Score, and The University of California Los Angeles-UCLA) were assessed preoperatively and at final follow-up. Transfusion decisions followed a standardized threshold (Hb < 7 g/dL or symptomatic anemia), and transfusion units were recorded. Radiographic leg-length discrepancy was measured on standardized AP pelvic radiographs. All patients were followed for at least one year.

RESULTS

Group 1 patients were younger and had lower preoperative functional scores. Both groups demonstrated significant postoperative improvements and the magnitude of functional gain was comparable. Mixed-effects modeling showed significant time effects for hemoglobin and hematocrit (p < 0.001), with no time × group interaction. Transfusion rates were higher in Group 1 (15.2% vs. 6.2%; risk ratio 2.44, 95% CI 1.06-5.63), largely attributable to lower preoperative Hb. No significant differences were observed in post-operative complications or leg length discrepancies.

CONCLUSION

Postoperative functional outcomes after THA are primarily influenced by preoperative functional status rather than prior DDH surgery. Early postoperative blood loss is not significantly affected by previous open surgery. These findings underscore the importance of thorough preoperative counseling and expectation management.