Intensive basketball linked to degenerative hip deformity
MedWire News: Children and adolescents who play basketball intensively display a hip deformity that is associated with pain and an increased long-term risk for osteoarthritis, researchers have found.
Cam-type deformity presents as a nonspherical extension of the articular surface at the anterosuperior head-neck junction and is associated with a reduction in range of internal rotation and impingement lesions, explain Klaus Siebenrock (University of Bern, Switzerland) and co-authors.
The etiology of cam-type deformities has been attributed to factors including growth disorders, congenital abnormality, and intensive sporting activity during key stages of development, note the researchers.
To investigate further, the team examined 72 hips in 37 male basketball players, aged between 9 and 25 years old (mean age, 17.6 years) and 76 hips in 38 age-matched individuals without hip symptoms who did not play high-level sport.
Overall, 15% of hips in the athletes were painful and showed anterior impingement.
Average internal rotation of the hip was significantly smaller in the athletes compared with controls at 18.9° and 30.1°, respectively. Although internal rotation was comparable in athletes and controls aged 9-12 years, by age 13-15 years rotation was significantly reduced in athletes and this difference remained pronounced in later years.
In addition, the athletes had a larger maximum value of alpha angle through the anterosuperior head segment than controls (60.5° vs 47.4°). An angle of 50-55° is considered normal after physeal closure, and this was exceeded in 9% of control hips but 89% of hips in athletes.
However, angle values in hips of athletes with an open physis, after an average of 5.5 years of training, were still within normal range, although higher than in controls.
"Our data suggest the cam-type deformity is in part a developmental deformity, and that its expression in young adulthood may be triggered by environmental factors such as high-level sports activity during childhood and around the time of closure of the capital growth plate," Siebenrock et al write in the journal Clinical Orthopaedics and Related Research.
"Given the role of the cam-type deformity in femoroacetabular impingement and early degenerative changes in the hip, we suggest changes in morphologic features of the femur resulting from vigorous sporting activity are a key component in the elevated incidence of hip osteoarthritis observed in athletes," they add.
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By Lynda Williams