Physical activity during adolescence and the development of cam morphology: a cross-sectional cohort study of 210 individuals.

Palmer A., Fernquest S., Gimpel M., Birchall R., Judge A., Broomfield J., Newton J., Wotherspoon M., Carr A., Glyn-Jones S.

INTRODUCTION: Cam morphology is a strong risk factor for the development of hip pain and osteoarthritis. It is increasingly thought to develop in association with intense physical activity during youth; however, the aetiology remains uncertain. The study aim was to characterise the effect of physical activity on morphological hip development during adolescence. METHODS: Cross-sectional study of individuals aged 9-18 years recruited from Southampton Football Club Academy (103 male) with an age-matched control population (52 males and 55 females). Assessments included questionnaires and 3 Tesla MRI of both hips. Alpha angle, epiphyseal extension and epiphyseal tilt were measured on radial images. RESULTS: Alpha angle and epiphyseal extension increased most rapidly between ages 12 and 14 years. Soft-tissue hypertrophy at the femoral head-neck junction preceded osseous cam morphology and was first evident at age 10 years. The greatest increase and highest absolute values of alpha angle and epiphyseal extension were colocalised at 1 o'clock. Maximum alpha angles were 6.7 degrees greater in males than females (p=0.005). Compared with individuals who play no regular sport, alpha angles were 4.0 degrees higher in individuals who play sport for a school or club (p=0.041) and 7.7 degrees higher in individuals competing at a national or international level (p=0.035). There was no association with leg dominance . CONCLUSIONS: Sporting activity during adolescence is strongly associated with the development of cam morphology secondary to epiphyseal hypertrophy and extension with a dose-response relationship. Males participating in competitive sport are at particularly elevated risk of developing cam morphology and secondary hip pathology.

DOI

10.1136/bjsports-2017-097626

Type

Journal article

Journal

Br j sports med

Publication Date

05/2018

Volume

52

Pages

601 - 610

Keywords

MRI, football, hip, physical activity, sport, Adolescent, Child, Cohort Studies, Cross-Sectional Studies, Exercise, Female, Femur Head, Femur Neck, Hip Joint, Humans, Magnetic Resonance Imaging, Male, Osteoarthritis, Pain, Risk Factors

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