The percentage of boys and girls who return to competitive basketball or soccer after anterior cruciate ligament (ACL) repair are similar, according to study findings presented Wednesday at the American Academy of Orthopaedic Surgeons annual meeting in Las Vegas. The investigators also found that the time patients returned to full sports was not associated with a repeat injury.

The anterior cruciate ligament is one of four strong ligaments that hold the bone of the upper leg and the bone of the lower leg together. Located in the front of the knee, an ACL injury causes swelling, loss of stability, immobility and other symptoms.

Surgical repair is usually needed, but with more serious injuries, ACL reconstruction surgery is performed in which a "graft" is used to replace the ligament. Tissue from another area of the body is commonly used or implantation of a donor graft is another option.

Others studies have examined gender differences in returning to sports activities after ACL reconstruction, lead author Dr. K. Donald Shelbourne told Reuters Health, but they have included all sports and patients of all ages.

"Our study," said Shelbourne, from the Shelbourne Knee Center, Indianapolis, Indiana, "specifically looked at school-aged boys and girls in basketball and soccer." The average age was 15 years old, an age group with the highest risk of ACL injury. "Athletes at this age are extremely motivated to return to sports quickly," he added.

The study featured 413 consecutive subjects who were younger than 17 years of age at the time of ACL reconstruction for an injury sustained playing basketball or soccer. Follow-up data were available for 402 subjects (97 percent), including 242 girls and 58 boys in basketball and 77 girls and 25 boys in soccer.

In basketball athletes, the percentage of boys and girls who returned to compete in high-school basketball was identical, at 87 percent. The average time to full participation after surgery was roughly 5.2 months in both groups. Twenty-one percent of girls and 17 percent of boys went on to compete in basketball in college.

For soccer, more girls returned to compete in high school soccer than boys, but the difference was not statistically significant: 93 percent vs. 80 percent. The average time to full participation was 5.1 months in both groups. Thirty-three percent of women and 24 percent of men would later compete in soccer in college.

Shelbourne's group found that "the time to return to full sports was not a significant factor related to the incidence of any subsequent ACL injury to either knee after surgery. So, patients who returned to full sports at 3 to 4 months did not have a higher incidence of (re-injury) than patients who did not return until after 6 months."

The take-home message for patients and physicians is that "boys and girls can return to basketball and soccer at the same level and rate after ACL reconstruction" and girls are not more likely to quit the sport than are boys. "The subsequent injury rate in these young athletes in high-risk sports is 10 percent to 16 percent, but the time to full return is not a factor for re-injury."