Adolescent participation in high-intensity sports linked to high osteoarthritis rates

Participation in vigorous sporting activities during childhood and adolescence can cause abnormal development of the femur in young athletes and may lead to hip deformation, such as reduced rotation and pain during movement, according to Swiss researchers.

The findings, published online in Clinical Orthopaedics and Related Research, may explain why athletes are at higher risk than more sedentary individuals to develop osteoarthritis.

“Our data suggest that this hip deformity is in part a developmental deformity, and 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 femoral growth plate,” the Klaus A. Seibenrock, MD, and his fellow authors wrote.

“Given the role of the deformity in degenerative changes in the hip, morphological features of the femur resulting from vigorous sporting activity are a key component in the elevated incidence of hip osteoarthritis observed in athletes,” they added.

The team performed a retrospective review of 72 hips in 37 male basketball players with a mean age of 17.6 years. They also investigated 76 asymptomatic hips in 38 age-matched volunteers who had not participated in high-level sporting activities.

According to the study abstract, 11 (15%) of the 72 hips in the athletic cohort were reported as painful, with physical examination revealing positive anterior impingement tests. Mean internal rotation of the hip in the athletic cohort was 18.9°, while the control group displayed a mean internal rotation of 30.1°.

The athletic cohort also displayed a larger maximum value of alpha angle throughout the anterosuperior head segment than that found in the control group, with these differences growing more pronounced following capital growth plate closure.

“Overall, the athletes had a 10-fold increased likelihood of having an alpha angle greater than 55° at least at one measurement position,” the authors wrote. “Our observations suggest a high intensity of sports activity during adolescence is associated with a substantial increase in the risk of cam-type impingement. These patients also may be at increased risk of subsequent development of secondary coxarthrosis.”

Reference:

Siebenrock KA, Ferner F, Noble PC, et al. The cam-type deformity of the proximal femur arises in childhood in response to vigorous sporting activity. Clin Orthop Relat Res. 2011. doi: 10.1007/s11999-011-1945-4

www.springer.com

Hip impingement in athletes has become a well recognized source of pain and functional limitations. The study by Siebenrock et al nicely demonstrates that hip impingement and decreased hip internal rotation in adolescent athletes exists more frequently when compared to non-athletes. This suggests an important developmental etiology of hip impingement based on exposure to stresses during skeletal growth. This study will serve to stimulate further research to determine the exact timing in skeletal age and features of repetitive stress that may lead to pathologic changes. This study also relates to research that has found decreased hip internal rotation in the trail leg of pitchers.(Laudner et al, AJSM 2010) Interestingly, this group of athletes experience asymmetric repetitive stress and therefore develop asymmetric pathology. Lastly, it also well recognized that young throwing athletes develop osseous changes in their dominant proximal humerus due to unique repetitive stresses subjected to that area. Improved understanding of the magnitude and timing of repetitive stresses to young joints will likely lead to prevention strategies that may decrease young athletic injuries such as labral tears and late conditions such as degenerative arthritis.

— Christopher S. Ahmad, MD
Head Team Physician, New York Yankees
Dept. of Orthopedic Surgery
Columbia University

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