Predicting Radial Head Dislocation in Hereditary Multiple Osteochondromatosis: A Quantitative Radiologic Approach

Area of Science:

• Orthopedics
• Pediatric Radiology
• Skeletal Dysplasias

Background:

• Hereditary multiple osteochondromatosis (HMO) frequently causes forearm deformities in children.
• Radial head dislocation (RHD) is a significant complication, potentially preventable with early detection.
• Current classification systems lack reliability for guiding surveillance and treatment decisions.

Purpose of the Study:

• Identify radiologic predictors of RHD in pediatric HMO patients.
• Develop a quantitative, clinically applicable classification system for RHD risk stratification.
• Support growth-oriented surveillance and surgical decision-making.

Main Methods:

• Retrospective review of 143 patients (186 forearms) with HMO (2006-2024).
• Radiographic analysis included lesion distribution, proportional ulnar length (PUL), radial bowing, ulnar variance, and RHD presence.
• Multivariate analysis to identify RHD predictors and develop a risk-based classification framework.

Main Results:

• RHD occurred in 36% of forearms.
• Lower PUL (≤0.89) was a significant predictor of RHD.
• Absence of distal radius lesions increased RHD likelihood; radial bowing and ulnar variance were not independent predictors.
• A 3-tier risk classification (Type A1, A2, B) based on PUL and distal radius lesions was developed.

Conclusions:

• Proportional ulnar length (PUL) is the most reliable radiographic predictor of RHD in HMO.
• Integrating distal radius lesion status enhances risk stratification for pediatric patients.
• The proposed system offers a reproducible, growth-oriented framework, addressing limitations of existing classifications.