Factors associated with symptom development in bilateral hip dysplasia with comparable acetabular coverage

Area of Science:

• Orthopedic surgery
• Radiology
• Biomechanical analysis

Background:

• Bilateral hip dysplasia (HD) presents complex diagnostic challenges.
• Identifying morphological predictors of symptomatic hip joints is crucial for targeted treatment.
• Understanding the interplay between acetabular and femoral morphology in HD is essential.

Purpose of the Study:

• To investigate morphological distinctions between symptomatic and asymptomatic hips in patients with bilateral hip dysplasia (HD).
• To determine if specific femoral or acetabular parameters correlate with hip pain in bilateral HD.
• To compare the diagnostic value of acetabular sector angles (ASAs) versus femoral parameters in symptomatic hips.

Main Methods:

• Comparative analysis of 33 patients with bilateral HD undergoing eccentric rotational acetabular osteotomy (ERAO).
• Three-dimensional measurement of acetabular sector angles (ASAs), femoral neck anteversion (FNA), and femoral head lateralization.
• Statistical comparison between symptomatic and asymptomatic hips using paired t-tests and conditional logistic regression.

Main Results:

• The First Cohort showed lower ASAs on the symptomatic side, but this was not significant in the Second Cohort (matched for lateral centre-edge angle - CEA).
• Both cohorts demonstrated significantly greater FNA and femoral head lateralization on the symptomatic side.
• Increased FNA (OR: 1.3) and lateralization (OR: 4.6) were identified as significant predictors of hip pain in bilateral HD patients.

Conclusions:

• When CEA is comparable in bilateral HD, increased FNA and femoral head lateralization are stronger indicators of symptomatic hips.
• Acetabular parameters may be less critical than femoral morphology in predicting pain when CEA is similar.
• This finding aids in better identifying the primary source of pain in bilateral hip dysplasia.