Women Risk Bone Loss After Knee Surgery

Women who play sports are prone to tearing the Anterior Cruciate Ligament (ACL). Beyond the immediate pain and swelling it can cause, there’s now reason to suspect that this type of injury may lead to another vexing health problem.

Researchers at the Mayo Clinic in Rochester, Minn., found that young women who had surgery to repair the anterior cruciate ligament (ACL) suffered significant bone loss around the knee even two years later. And that damage was seen even though they had undergone rehabilitation.

“Despite telling them to weight-bear early and put weight on the leg, people are going to protect an operative limb,” said study author Dr. Diane L. Dahm, an assistant professor of orthopedics at Mayo. “So, it’s probable that the forces going across that operative limb were not as great as the opposite limb, early on especially.”

The findings were first reported at a meeting of the American Academy of Orthopaedic Surgery (AAOS).
Dahm and her colleagues studied 18 female athletes ranging in age from 16 to 40. All were fairly active and involved in some sort of exercise, although not necessarily an organized sport. The researchers chose age 40 as the cutoff to eliminate any patients who might have osteoporosis related to early menopause.

After undergoing ACL reconstruction, the women participated in a rehabilitation program that involved routine visits with physical therapists and sports psychologists.

Before surgery, there were no significant differences in bone density between the injured and uninjured legs. Three months after surgery, however, the researchers found striking differences in bone density between the injured limb and the unaffected one. While there were improvements in the women’s injured limbs over two years, “they did not get back to completely normal,” Dahm observed
Given the incidence of ACL injuries among women, orthopedists urge women athletes to take steps to prevent ligament tears from occurring. The AAOS recommends year-round training and conditioning, including strength training and practicing performing proper landing and cutting maneuvers.