THURSDAY, March 3, 2005 (HealthDay News) -- Tears of the knee's anterior cruciate ligament also increase the risk and severity of knee osteoarthritis, even in people who may not remember suffering a major knee injury in the past, researchers report.
The anterior cruciate ligament (ACL) helps support the knee, but injuries to this ligament are common, especially among athletes. However, not much has been known about the long-term effect, if any, of these tears on the joint.
Reporting the March issue of the journal Arthritis & Rheumatism, researchers compared 360 men and women, mean age 67, with advanced, painful knee osteoarthritis, to another 73 control subjects. Of those in the control group, 48 had knee osteoarthritis but no pain and 25 had neither knee osteoarthritis symptoms nor knee discomfort.
Overall, the people in the study group had a slightly higher body mass index (BMI) than those in the control group. The participants were recruited by Boston University Medical Center and the Boston Veterans Affairs
Healthcare System.
Magnetic resonance imaging (MRI) was used to assess the prevalence of past cruciate ligament tears in all participants.
Posterior cruciate ligament (PCL) tears were found in less than 1 percent of the study group and in none of the controls. However, complete anterior cruciate ligament tears were found in nearly 25 percent of those in the study group with advanced knee osteoarthritis, compared to less than 3 percent of the controls.
Knee osteoarthritis was assessed as more severe in people with ACL tears than in those with intact ACLs. However, the people with partial or complete ACL tears didn't experience more pain than the others, the study said.
Fewer than half of the patients with complete ACL tears -- about 48 percent -- reported a previous knee injury.
"Due to the cross-sectional nature of this study, we could not ascertain when the ACL ruptures occurred. The interval between ACL injury and significant knee symptoms may be as long as 30 years, providing one explanation for the low recall of significant knee injury in our study," Catherine L. Hill, one of the study authors, said in a prepared statement.
She and her colleagues concluded that complete ACL tears play a major, under-reported role in the development of knee osteoarthritis.
More information
The American Medical Association has more about knee osteoarthritis.
