Overuse Injuries Pediatric Research and Clinical Trials

For more than a century, orthopedic surgeons and investigators at Children’s Hospital Boston have played a vital role in the field of musculoskeletal research—pioneering treatment approaches and major advances in the care and treatment of trauma to the joint, scoliosis, polio, TB, hip dysplasias and traumas to the hand and upper extremities.

Our advanced research helps answer the most pressing questions in pediatric orthopedics today—providing the children we treat with the most innovative care available.

Children’s research shows that too much high-impact training can lead to stress fractures in pre-teen and teen girls

Today’s kids are urged to participate in sports at younger and younger ages and at greater levels of intensity. While weight-bearing activity is generally thought to increase bone density, a Children's study found that for preadolescent and adolescent girls, too much high-impact activity can lead to stress fractures.

If stress fractures are detected too late in children and adolescent athletes, they pose a risk of true fracture, deformity or growth disturbance requiring surgical treatment, say the researchers, led by Alison Field, ScD, of Children's Division of Adolescent Medicine, and Mininder S. Kocher, MD, MPH, associate director of Sports Medicine at Children's.

Their study, published online on April 4, 2011, by the Archives of Pediatric and Adolescent Medicine, followed 6,831 girls aged 9 to 15 participating in the large national Growing Up Today study, co-founded by Field. During the seven years after enrollment, 4 percent of the girls developed a stress fracture. The most significant predictors were high-impact activities—particularly running, basketball, cheerleading and gymnastics.

"This is the first study to look prospectively at causes of stress fracture among a general sample of adolescent girls," says Field, who is also affiliated with Brigham and Women's Hospital. "Most research has been on specialized groups, such as army recruits or college athletes, making it difficult to figure out if the results apply to average adolescents. Our study was large enough to look at the risk associated not only with hours per week of activity, but also hours per week in a variety of activities."

When researchers adjusted for other risk factors (age, later onset of menstruation and family history of osteoporosis and low bone density), the association between high-impact sports and fractures only strengthened. Girls engaging in eight or more hours of high-impact activity per week were twice as likely to have a stress fracture as those engaged in such activity for four hours or fewer.

"We are seeing stress fractures more frequently in our pediatric and adolescent athletes," says Kocher, senior author on the report. "This likely reflects increased intensity and volume of youth sports. Kids are often playing on multiple teams, including town and travel teams, and participating in high-intensity showcases and tournaments. It's not uncommon to see young athletes participating in more than 20 hours of sports per week."

Each hour of high-impact activity per week increased fracture risk by about 8 percent. Basketball, cheerleading/gymnastics and running were independent predictors.

"The youth athlete is specializing in a single sport at a younger age," says Kocher. "This does not allow for cross-training or relative rest, as the athlete is constantly doing the same pattern of movement and impact. Small injuries are being made in the bone with greater cumulative frequency than the body can handle."

The key to the treatment of stress fractures is early recognition, Kocher adds. If recognized early, most stress fractures will heal fully with activity restriction. "Kids should not play through pain," he says. "'No pain-No gain' is not an appropriate adage for the young athlete."

The study was supported by the Department of Orthopedic Surgery at Boston Children's Hospital and the National Institutes of Health.

Sports Medicine Research Laboratory

Children’s Sports Medicine Research Laboratory, led by principal investigator Martha M. Murray, MD, focuses on sports medicine injuries, including those of the ACL (anterior cruciate ligament), knee meniscus and articular cartilage.

In conjunction with our collaborators, we are studying these problems on multiple levels: gene, protein, cell, tissue and organism.

Researchers at Children’s Sports Medicine Research Laboratory

The lab’s research includes projects in:

  • molecular orthopedics
  • platelet optimization and characterization
  • tissue engineering
  • joint imaging
  • biomechanics of injury repair
  • histology and immunohistochemistry
  • device design and development
  • injury prevention
  • outcomes research

The Orthopedic Center conducts research into:

  • the mechanisms of sports injuries
  • the techniques of rehabilitation and treatment
  • the physiology of exercise and conditioning

Ongoing research includes the study of:

  • knee injuries
  • running injuries
  • injuries to pre-adolescent children
  • the psychological impact of sports and sports injuries
  • the treatment and prevention of injuries to dancers

Sports Medicine director Lyle J. Micheli, MD, is one of the world's leading authorities on sports care. Micheli has treated world-renowned dancers and professional athletes, and is the author of hundreds of published clinical studies and scholarly review articles and books.

Innovations for tendon and ligament treatment

Platelet-rich plasma. For tendon repair, as with tennis elbow, the Orthopedic Center is now incorporating the latest in tendon regeneration—the application of platelet-rich plasma (PRP). This treatment has been popular in Europe—and now in the United States—for stimulating tissue regeneration in difficult-to-heal areas such as tendons (including Achilles, elbow and patella) that don’t respond to physical therapy or to limits on activity.

There are normally many healing growth factors in our platelets. The process involves isolating these growth factors in the patient’s blood platelets, and then injecting them into the affected areas under ultrasound guidance. This special procedure is performed by Children’s Pierre d'Hemecourt, MD.

Physeal sparing. A series of innovative, age-specific reconstruction techniques for treating the ACL injuries of growing children has been developed by Children’s orthopedic surgeon and director of the Division of Sports Medicine Lyle Micheli, MD. These are classified as physeal sparing procedures—that is, they spare the child’s growth plates (physes) from disruption that would occur in traditional ACL reconstructive surgery.

These physeal sparing treatment techniques are customized to the growing child’s age: pre-pubescent, adolescent or older adolescent. Originally developed as a temporary procedure until a child reached skeletal maturity, follow-up studies have found that five years after their surgeries, 95 percent of children who’d had physeal sparing procedures were doing so well that they didn’t need ACL reconstructive surgery, after all.

Overuse injuries in young girls
Mininder S. Kocher, MD, MPH, associate director of Children’s Sports Medicine and Alison Field, ScD, of Children's Division of Adolescent Medicine led a study showing that young girls are participating too frequently in high-impact sports which can lead to stress fractures, particularly from specialized participation in basketball, running, gymnastics or cheerleading. Learn more about this study in the Children’s newsroom.