Common Knee Injury Linked to Knee Arthritis

Torn Ligament Seen in More Than 20% of Knee Osteoarthritis Patients

From the WebMD Archives

Treating a common knee injury could help avoid knee osteoarthritis.

A new study reports that nearly one in four knee osteoarthritis patients had a tear in a major knee ligament -- the ACL (anterior cruciate ligament). Yet in the study less than half of the participants remembered ever having a knee injury.

ACL tears are common in sports that require jumping or shifts in weights such as basketball, soccer, or skiing. Falling forward and outward is a classic mishap that can lead to an ACL tear.

The ACL is one of the main ligaments of the knee, which connects the thigh and shin bone. When torn, the knee usually feels unstable. These tears can lead to injury to other structures within the knee that cushion the bony surfaces. In the long term, the knee develops osteoarthritis.

Paying more attention to our knees -- and the beating they take -- could pay off. A torn ACL isn't likely to heal on its own. Surgery can help stabilize the knee, and it might protect knees from osteoarthritis.

The new study didn't weigh the pros and cons of ACL surgery for future knee arthritis. Instead, it pinpointed torn ACLs as an overlooked risk factor for knee osteoarthritis.

A torn ACL is no small matter. It's a severe injury that can banish athletes to the disabled list, and if accompanied by pain and swelling it would probably be hard to overlook. Knee injuries are known to increase the chance of getting arthritis.

Participants were 360 people with painful knee osteoarthritis and 73 without knee pain. All were scanned on one knee.

The scan (MRI) showed that 48 of those without knee pain actually had damaging signs of knee osteoarthritis. But that wasn't the only thing that the images revealed.

The researchers scanned for the tell-tale signs of ACL injuries. They were looking for complete or partial tears of the ACL and another knee ligament, the posterior cruciate ligament (PCL).

In the study, nearly 23% of participants with knee osteoarthritis had signs of a complete ACL tear, compared with 2.7% of those without knee pain. PCL injuries were rare in both groups, seen in less than 1% of knee arthritis patients and none without knee pain.


Those with complete ACL tears also had more severe knee osteoarthritis.

The study appears in the March issue of Arthritis & Rheumatism. It was conducted by researchers including Catherine Hill, MB, BS, MSc, now of Australia's Queen Elizabeth Hospital.

In addition to avoiding injury, other ways to help prevent knee osteoarthritis are:

  • Weight control -- increased weight puts excessive stress on the knees
  • Exercise -- keeping the muscles around the knee strong and flexible can help decrease stress on the knee cartilage and even improve function in people with arthritis
WebMD Health News Reviewed by Brunilda Nazario, MD on March 03, 2005


SOURCES: Hill, C. Arthritis & Rheumatism, March 2005; vol 52: pp 794-799. WebMD Medical Reference from Healthwise: "Osteoarthritis: Topic Overview." WebMD Medical Reference from "The Knee Sourcebook": "Knee Injuries." News release, John Wiley & Sons, Inc.

© 2005 WebMD, Inc. All rights reserved.