Intensive training in young athletes. The orthopaedic surgeon's viewpoint.

A young athlete's musculoskeletal system is unique, in that it is not only growing, but is giving support to the growing soft tissues as well. With this in mind, it is easily understood that the fastest growing areas of children skeletal system are at greater risk of injury. No controlled longitudinal studies have yet been performed about the long term effects of injuries occurring in intensively trained young athletes. During the growth spurt, a dissociation between bone matrix formation and bone mineralisation occurs, thus leaving the child with the risks of chronic moderate-to-high overloading, sudden great overload, and diminished bone strength. This may account for both acute and overuse bone injuries in this age group. Epiphyseal plate injuries can have disastrous consequences. About 10% of all skeletal trauma in children involves the epiphysis, but few long-lasting effects have been reported. It is not clear whether intensively trained young athletes are at greater risk of injury than children engaged in free-play activities. It is worrying, though, that about 20% of injuries in sports children require internal fixation. Few studies have addressed injuries to tendons, ligaments and the enthesis in young athletes. It seems that tendon injuries are mild, not requiring surgery, and with a low recurrence rate, but no prospective studies have been performed. Avulsion of the ligamentous insertion occurs more frequently than ligament ruptures in this age group, even though they seem on the increase. Osteochondritis dissecans affects weightbearing joints such as the hip, the knee and the ankle, but elbow lesions in gymnasts and throwers are also relatively frequent. If it occurs before epiphyseal fusion, long term effects are scarce. The centre of growth or ossification where a major tendon is attached may undergo chronic inflammation and avulsion of cartilage and bone, due to the stresses transmitted to it. Typical areas are the inferior pole of the patella, the tibial tubercle and the calcaneal apophysis. Sports activity contributes to the disease by excessive traction at the tendinous and fascial insertion, or as a result of direct pressure. The lumbar spine is subjected to enormous forces in some sports. The true incidence of lumbar disc lesions in sporting children is not known, but it seems that acute trauma may play a major role. With the increase of the intensity and duration of training programmes, degenerative changes may play an adjuvant role.(ABSTRACT TRUNCATED AT 400 WORDS)