Stem cells may help repair ACL tears: report

A fluorescent microscope image shows human embryonic stem cells in this photo taken at Stanford University and released by the California Institute for Regenerative Medicine, March 9, 2009.

NEW YORK (Reuters Health) - A novel approach to repairing partially torn anterior cruciate ligaments in young athletes has shown promise, according to a group of orthopedic surgeons in Italy.

The anterior cruciate ligament, or ACL, is the key ligament stabilizing the knee, and is especially important for holding the joint steady during jumping, pivoting and twisting.

Dr. Alberto Gobbi and colleagues at Orthopedic Arthroscopic Surgery International in Milan found that combining standard ACL repair techniques with bone marrow stimulation helps restore stability and function in youthful athletes with acute partial ACL tears.

"Our technique," Gobbi told Reuters Health, "avoids the use of the patient's own hamstring or patellar tendon (in the kneecap) to reconstruct the native ACL," eliminating the problems associated with tendon "harvesting."

"Our goal is to enhance natural healing processes to regenerate the partially torn ACL," Gobbi added.

In The American Journal of Sports Medicine, Gobbi and colleagues note that standard ACL reconstruction is the conventional method and has about an 80 percent success rate.

To determine whether ACL repair combined with bone marrow stimulation of the ACL might also be of value, the researchers employed the approach in 26 athletes, ranging in age from 17 to 37 years. All of them had arthroscopically confirmed partial ACL tears.

The repair procedure involves suturing of the tear and creating small holes around the remaining healthy part of the ACL -- the idea being to facilitate release of mesenchymal stem cells from the bone marrow in order to promote healing. Mesenchymal stem cells are immature cells than can give rise to bone.

All the patients then participated in a rehabilitation program and, over time, the majority saw marked improvement in ACL functioning and improved knee stability.

Only five patients (19 percent) did not return to the same level of sports activity. This was by choice in three patients.

SOURCE: American Journal of Sports Medicine, March 2009.