Lower limb deformity and gait deviations of osteogenesis imperfecta

Area of Science:

• Orthopedics
• Genetics
• Biomechanics

Background:

• Osteogenesis imperfecta (OI) is a rare genetic disorder causing complex lower limb deformities.
• These deformities significantly impact gait and mobility in affected individuals.
• Understanding the relationship between radiographic findings and gait impairment is crucial for patient management.

Purpose of the Study:

• To investigate the incidence of radiographic lower limb deformities in OI patients.
• To determine the association between specific deformities and gait impairment.
• To develop and validate a novel lower limb deformity index for quantifying severity and reflecting gait performance.

Main Methods:

• Retrospective analysis of bilateral X-ray images and 3D gait data from 48 OI patients.
• Multivariate linear regression to assess the contribution of individual deformities to gait deviation.
• Evaluation of eight scoring approaches for a proposed lower limb deformity index based on radiographic changes.

Main Results:

• High incidence of femur bowing, tibia bowing, hip abduction, knee varus, hip flexion, and ankle dorsiflexion deformities observed in OI patients.
• Reduced joint kinematics and kinetics compared to healthy controls, correlating with deformities.
• Individual deformities showed limited contribution to gait deviation, except for mechanical axis deviation.
• The proposed lower limb deformity index demonstrated a significant linear correlation with gait deviation (R²=0.423, p<0.001).

Conclusions:

• A preliminary association between lower limb deformities and gait deviations in OI patients was established.
• A novel lower limb deformity index was proposed, effectively quantifying deformity severity.
• The index shows promise in reflecting overall gait performance in individuals with Osteogenesis Imperfecta.