Does Deformity Severity Dictate Which Side Initially Develops Symptoms in Bilaterally Dysplastic Hips?

Area of Science:

• Orthopedics
• Biomedical Engineering
• Radiology

Background:

• Developmental dysplasia of the hip (DDH) often presents with bilateral deformities but asymmetric symptoms, a phenomenon not fully understood.
• Understanding the relationship between deformity severity and symptom asymmetry is crucial for effective patient management.

Purpose of the Study:

• To investigate the correlation between hip deformity severity and symptom asymmetry in patients with bilateral DDH.
• To determine whether acetabular or femoral deformities are more closely associated with symptomatic hip presentation.

Main Methods:

• Hip geometry was measured in 230 patients using lateral center-edge angle (LCEA), acetabular inclination, neck-shaft angle, alpha angle, and femoral version.
• Measurements were compared between initially symptomatic hips and contralateral hips.
• Patients were categorized based on the severity of side-to-side LCEA differences and activity levels were assessed.

Main Results:

• Symptomatic hips exhibited more severe acetabular deformities (LCEA and acetabular inclination) in 80% of subjects (p < 0.001).
• A more severe neck-shaft angle was observed in symptomatic hips for most patients (p = 0.003), but with a small effect size.
• No significant difference in activity levels was found between patients with more deformed symptomatic hips versus those with more deformed contralateral hips.

Conclusions:

• Acetabular deformities appear to be the primary driver of asymmetric symptom development in bilateral DDH, more so than femoral deformities.
• Self-reported activity levels did not correlate with symptom asymmetry, suggesting other factors may be involved.
• These findings enhance understanding of DDH progression and symptom onset, informing targeted interventions for pain reduction and long-term joint health.