Tears of the knee's anterior cruciate ligament (ACL) increase the risk and severity of knee osteoarthritis even in people who may not remember experiencing a major knee injury in the past, researchers report.
The ACL helps support the knee, and tears of this ligament are fairly common, especially among athletes, but little has been known about their long-term effect.
The Study
The study compared 360 people, who had a mean age of 67, and had advanced, painful knee osteoarthritis, with 73 "control patients. Of that latter group, 48 had knee osteoarthritis but no pain and 25 had neither knee osteoarthritis nor discomfort.
Magnetic resonance imaging (MRI) was used to assess past ACL tears in all participants.
Complete tears of the ACL, on the front of the knee, were detected in nearly 25% of the patients who had advanced knee osteoarthritis, compared with less than 3% of the people in the control group.
This suggests that complete tears of the ACL play a major-but underreported—role in the later development of knee osteoarthritis In addition, knee osteoarthritis was assessed as more severe in people who had experienced ACL tears than in those who had not.
No Memory Of Injuries
Interestingly, fewer than half of the patients who had complete ACL tears—approximately 48%—reported that they had had a knee injury.
"We could not ascertain when the ACL ruptures occurred, according to Catherine L. Hill, the author of the study.
"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," Hill explains
Anti-Inflammatory Creams Relieve Knee Pain
Creams containing pain-relieving nonsteroidal anti-inflammatory drugs (NSAIDs) can ease the symptoms of knee arthritis.
This is especially good news for people who experience gastrointestinal problems when taking aspirin, acetaminophen or ibuprofen orally.
Researchers treated 228 men and women who had osteoarthritis in at least one knee with a topical NSAID solution containing diclofenac sodium.
Patients using the solution had a 46% reduction in knee pain, a 37% improvement in physical function and a 35% reduction in knee stiffness, according to the research team at Arizona Research & Education in Phoenix.
The patients also reported a 45% reduction in pain while walking.
Adverse effects of the solution were generally limited to minor skin irritation, dry skin or rash. These side effects affected fewer than half of patients.