Anterior cruciate ligament (ACL)

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.

ACL research

Research led by Children’s orthopedic surgeon and principal investigator Martha Murray, MD, focuses on stimulating the healing of tissues inside joints—particularly the ACL and meniscus of the knee.

Treating these injuries remains one of the most challenging problems facing orthopedic science today, since damaged ACL ligaments have almost no ability to repair or regenerate. Surgery is typically performed to remove the injured tissue and replace it with healthy graft tissue. But this procedure can lead to a high rate of premature arthritis in the knee (as high as 80 percent 14 years after an ACL tear), and isn’t suitable for children who are still growing.

Murray’s Sports Medicine Research Laboratory team is developing a new technique to stimulate natural ACL healing. In animal studies, they’re finding that an enriched collagen gel can stimulate natural healing—creating a “bridge” between the two torn ends that provides a medium for the cells to come back into and heal.

Fig. 1              Fig. 2              Fig. 3              Fig. 4

            Fig. 1 ACL is torn

            Fig. 2 Healing does not occur when blood clot dissolves in joint fluid

            Fig. 3 Collagen and blood plasma mixture is injected

            Fig. 4 ACL heals successfully

Although it will be years before researchers test the technique in people, it’s already showing promising results, and may help prevent early arthritis by restoring the knee closer to “normal” than grafting can. Plus, it’s much less invasive—requiring just two incisions, in contrast to grafting with segments of the patella and/or other tissues.

Orthopedic basic science laboratories

Working in Boston Children’s orthopedic research labs are some of the nation’s leading musculoskeletal researchers. These labs include:

• Sports medicine research laboratory
• Orthopedic basic science research
• Center for the study of genetic skeletal disorders
• Bone cell biology laboratory
• Matthew Harris Laboratory

_{Ligament and tendon innovations}

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 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.

Platelet-rich plasma.The Division of Sports Medicine is now incorporating the latest in tendon regeneration—the application of platelet-rich plasma. 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 with ultrasound guidance.

Division of Sports Medicine

The Division of Sports Medicine 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

Program 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.