The genesis of Perthes' disease: does it lie in hips with reduced ranges of movement?

Area of Science:

• Orthopedics
• Pediatric Musculoskeletal Health
• Comparative Anatomy

Background:

• Perthes disease (Legg-Calvé-Perthes disease) is more prevalent in Caucasian children than in Black African children.
• Hip joint range of motion is a critical factor in musculoskeletal health and injury prevention.

Purpose of the Study:

• To compare hip joint range of movement between normal Ghanaian (African) and British (Caucasian) children aged 5–6 years.
• To investigate if a restricted range of hip movement in unaffected hips of children with Perthes disease is a predisposing factor.

Main Methods:

• A comparative analysis of hip joint range of movement was performed on 100 normal Ghanaian children and 182 normal British children.
• Hip range of movement was assessed in terms of flexion, abduction, internal rotation, and external rotation.
• The unaffected hips of 51 Caucasian children diagnosed with unilateral Perthes disease were also analyzed.

Main Results:

• Ghanaian children exhibited a significantly greater range of hip movement across all measured parameters compared to British children (P<0.001).
• Female children, in both racial groups, demonstrated a larger range of hip movement than male children.
• Unaffected hips in children with Perthes disease showed a reduced range of movement, particularly in flexion, abduction, and specific rotational movements (P<0.001).

Conclusions:

• Greater hip joint flexibility in children of African descent may offer a protective effect against the development of Perthes disease.
• A pre-existing restricted range of hip movement could be a significant risk factor, predisposing children to strain injuries and subsequent Perthes disease.