gms | German Medical Science

Objectives: Periacetabular osteotomy (PAO) is a well-established procedure for acetabular reorientation and showed successful improvement in patient-reported outcomes in hip dysplasia. The mainly young and active patients have a high functional demand, making the improvement in hip joint function and patients activity level particularly crucial. Thus, meticulous preoperative guidance on the postoperative outcome to expect based on patient individual factors is necessary.

Therefore, this case-series aimed to analyze thefunctional outcome and activity level in relation to gender and severity of hip dysplasia with a minimum follow-up of 2 years after PAO.

Methods: 150 patients (33 male, 117 female) undergoing hip preservation surgery by PAO for hip dysplasia (HD) and borderline hip dysplasia (BHD) were prospectively enrolled in this monocenter study. All patients completed a preoperative and postoperative radiographic and clinical outcome assessment. The patient-reported outcomes were assessed using the modified Harris-Hip score (mHHS), the Hip Osteoarthritis Outcome Score (HOOS) with the subscales for sport,pain, quality of life and activity in daily life and the University of California Los Angeles activity score (UCLA).

Intragroup analysis were conducted using the Wilcoxon-Test, while intergroup analysis were performed using the Mann-Whitney-U-Test. A p-value less than 0.05 was considered statistically significant.

Results and conclusion: The mean age at the time of surgery was 32.4 ± 8.3 years, without significant differences between male and female patients. There were no statistical significant gender-related differences between the mean postoperative lateral-center edge angle (m/f, 26.6° vs. 28.3°) and mean acetabular inclination (m/f, 3.0° vs. 2.1°).

At the latest follow-up, the patient-reported outcomes improved significantly across male and female patients, while female patients had significant lower preoperative scores and therefore experienced a significant higher improvement after PAO compared to their male counterparts (mf/f, mean difference score mHHS 30 vs. 36; mean difference score HOOS 21 vs. 31, p<0.05). Subgroup analysis comparing male and female patients with HD or BHD respectively showed a significantly greater gender-related effect in BHD than in HD.

Overall, this study indicated an influence on patients outcome by gender as well as severity of hip dysplasia in patients undergoing PAO. Female patients with BHD experienced the highest improvement in hip function and activity level. Thus, this data are of particular interest in providing preoperative guidance regarding postoperative outcome expectations.