Simultaneous Development of Hip Parameters with Cam Morphology: 5-Year Study
Overview
This longitudinal study of adolescent male football players investigated the relationship between clinical and radiological hip parameters and cam morphology development over five years. Findings indicate that neck-shaft angle, epiphyseal extension, lateral center-edge angle, and internal rotation are associated with cam morphology presence but do not precede its development.
Background
Cam morphology is characterized by extra bone formation at the anterolateral head–neck junction of the proximal femur and is linked to an increased risk of hip osteoarthritis. It typically develops during growth, is more prevalent in males and athletes, and may be influenced by biomechanical stress and growth plate orientation. Prior cross-sectional studies have associated cam morphology with lower neck-shaft angles and extended growth plates, but longitudinal data on whether these parameters precede cam morphology are lacking. Understanding these relationships could help identify adolescents at risk for cam morphology and guide preventive strategies.
Data Highlights
Parameter
Association with Cam Morphology
Preceding Development
Neck-Shaft Angle (NSA)
Lower NSA associated with cam morphology presence
Did not precede cam morphology development
Epiphyseal Extension (EE)
Increased EE associated with cam morphology presence
Did not precede cam morphology development
Lateral Center-Edge Angle (LCEA)
Associated with cam morphology presence
Did not precede cam morphology development
Internal Rotation
Reduced internal rotation associated with cam morphology presence
Did not precede cam morphology development
Key Findings
Cam morphology presence was defined by alpha angle ≥ 60° on AP or frog-leg lateral radiographs.
Lower neck-shaft angles were associated with cam morphology but did not predict its future development.
Greater epiphyseal extension correlated with cam morphology presence but was not a precursor.
Lateral center-edge angle showed association with cam morphology but did not precede it.
Reduced hip internal rotation was linked to cam morphology presence but did not occur before cam morphology development.
These hip parameters develop simultaneously with cam morphology rather than preceding it.
Clinical Implications
Clinicians should recognize that while certain radiographic and clinical hip parameters are associated with cam morphology, they do not serve as early predictors before its onset. Therefore, screening for cam morphology in adolescents based solely on these parameters may not effectively identify those at highest risk. Preventative strategies should focus on monitoring cam morphology development directly rather than relying on these associated hip parameters.
Conclusion
This 5-year longitudinal study demonstrates that clinical and radiological hip parameters develop concurrently with cam morphology rather than preceding it. These findings suggest that these parameters are markers of cam morphology presence but not predictive risk factors.
References
van Klij P et al. 2024 -- Simultaneous Development of Clinical and Radiological Hip Parameters with Cam Morphology: Findings from a 5-Year Follow-Up Study
