Anterior Cruciate Ligament Tear
Saturday, March 28, 2009
Paul Auerbach, M.D.
Outdoor and wilderness athletes put a lot of stress on their joints. Whether you are skiing, climbing, biking, hiking, running, or doing any other activity at which you are risk for deceleration, a fall, or a blow to the knee, there is a risk of injuring the joint. A common sports injury is a torn anterior cruciate ligament. This problem is succinctly reviewed by Drs. Kurt Spindler and Rick Wright in the Clinical Practice section of a recent issue of the New England Journal of Medicine. (N Engl J Med 2008;359:2135-42)According to the authors, the anterior cruciate ligament (ACL) is the most commonly injured ligament in the body for which surgery is frequently performed. This probably underestimates the problem because of failure to make the diagnosis. Women in sports appear to have a higher incidence of injury than do men, perhaps due to differences in leg alignment (increased incidence of "knock knee"), less space within the knee joint for the ligment, hormonal factors that would weaken the ligament, and perhaps less overall joint control during vigorous activities. Regardless of whether a person is a male or female, the injury leads to an increased incidence of "premature" knee osteoarthritis.
ACL tear is very often accompanied by other injuries, including those to a meniscus, joint cartilage, bone, and other ligaments. When the injury occurs, sometimes it is obvious, because of the mechanism of injury and/or hearing an audible popping sound, swelling from bleeding into the knee, and lack of function. When the ligaments on the sides of the knees ("collateral" ligaments) are injured, they generally do not cause swelling, and meniscal tears show delayed swelling.
The diagnosis may be made by the history, supplemented by a Lachman test (in which the lower leg is pulled anteriorly against a fixed femur, to detect instability) and, when necessary, magnetic resonance imaging (MRI) examination. In the acute phase of injury, the victim may be able to walk normally and perform "straight-plane" activities, such as stair climbing, biking, and even jogging. However, if he or she is unstable in normal activities or wishes to resume activities that call for cutting motions and pivoting, or is engaged in a profession or activity in which complete stability of the knee is essential (and safe), then surgery may be required.
In the acute phase of injury, the knee should be treated as would any other ligament injury, with rest, ice compression and elevation. Bracing or taping the knee may be helpful. Surgery may not be advised for a period of weeks, until the bleeding has subsided and the joint swelling receded.
Join me from January 24 to February 2, 2010 for an exciting dive and wilderness medicine CME adventure aboard the Nautilus Explorer to Socorro Island, Mexico to benefit the Wilderness Medical Society.
image courtesy of www.eorthopod.com
Tags: anterior cruciate ligament, injured ligament, knee injury, wilderness medicine, outdoor medicine, healthline
Labels: anterior cruciate ligament, knee injury, ligament injury
3 Comments:
At Wed Apr 01, 06:45:00 AM 2009,
ulsh72 said…
Great Post!
Could you provide a follow up post on the much less know PCL injury for your readers? Having suffered a PCL injury, and subsequent surgical repair, it gets much less coverage and is much lesser known than the ACL.
At Fri Apr 03, 06:45:00 AM 2009,
Haliku said…
In the acute phase of injury, the victim may be able to walk normally and perform "straight-plane" activities, such as stair climbing, biking, and even jogging.
Well that cinches it for me. I've been ignoring, what I hope is a minor knee problem for a couple of months now since I can do all those activities. But to avoid unknown further damage I now have an appointment with a sports Doc next week. Cheers!
At Sun Apr 05, 09:31:00 AM 2009,
kneedoc said…
My compliments on a very concise and timely posting.
I would offer a couple of comments. Regarding physical examination, I have found the pivot shift test to be quite helpful, especially if it is positive, asymmetrical (i.e. significantly increased compared to the normal knee, and reproduces the patients symptoms of "buckling" or instability. In those cases, there is a very high likelihood of a torn ACL.
With regard to treatment in the acute phase, I would agree with the author's recommendations, but would suggest a few additions. Quadriceps and range of motion exercises should be begun as early as can be tolerated, using ice applications to help control knee joint swelling. Stiffness and weakness are common sequeli after an ACL injury and early protected exercises can shorten the recovery period. Additionally, one should be cautious about the prolonged use of knee immobilizers since while offering protection against further injury, they promote stiffness and weakness. Alternatively, I prefer the use of crutches which allow controlled weight bearing, and protected range of motion.
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