The underused hip in ipsilaterally orthotics-dependent children

Area of Science:

• Pediatric Orthopedics
• Biomechanics
• Developmental Dysplasia

Background:

• Children requiring long-term orthotics/prosthetics for leg deformities often exhibit in-toeing gait and Duchenne's limp.
• These conditions can lead to coxa valga antetorta and hip decentration in otherwise healthy hips.
• Investigating the risk of hip decompensation and structural changes due to underuse is crucial.

Purpose of the Study:

• To assess the development of healthy hips in children with long-term orthotics/prosthetics dependency.
• To determine if underused hips are at risk of decompensation.
• To understand how external shape and internal architecture of hips change with disuse.

Main Methods:

• Instrumental gait analysis was performed on ten children with healthy hips and unilateral orthotics/prosthetics dependency.
• Results were correlated with clinical findings, activity scores, and radiographic data.
• A Level II retrospective study design was employed.

Main Results:

• Significant changes were observed in the affected hips, including increased internal rotation and decreased external rotation.
• Radiological analysis revealed increased angles (caput-collum-diaphyseal, head-shaft, Sharp, acetabular) and distance (lesser trochanter to articular surface).
• Gait analysis showed increased stride length, shortened stance phase, reduced ground forces, and increased hip abduction.

Conclusions:

• Duchenne's limp and reduced weight-bearing stress are key factors in developing coxa valga and acetabular dysplasia.
• These hip changes align with the mechanobiological principle that function influences bone and joint design.
• A precautionary pelvic radiograph at puberty is recommended for children with these conditions.