We have all heard and most of us know that exercise is good for us. For those of us who are disciplined enough to carve out the time to exercise in what are usually busy schedules, the benefits speak for themselves. Most of us, however, try to condense too much exercise into too little time and that’s when injuries occur.
The knee is one of the most complex joints in the body. Its unique design allows it to not only bend and straighten, but also to tolerate rotational movements under the stresses of weight bearing. For a runner, these stresses can be of the magnitude of 7-10 times the individual’s body weight in rotational force and impact load.
The soundness of the knee joint depends on the integrity of the four primary ligaments as well as multiple muscles, tendons and secondary ligaments to maintain proper function.
There are ligaments on each side of the knee, the medial collateral and the lateral collateral ligaments and two crossed ligaments in the center of the knee, the anterior and posterior crucial ligaments. The position of the anterior crucial ligament (ACL) keeps the thigh bone from twisting excessively on the lower leg.
Anterior Crucial Ligament Tears
The Anterior Cruciate Ligament or ACL is usually injured either from a direct blow to the knee or from a non-contact injury such as planting one’s foot firmly on a playing surface and making an abrupt stop or changing direction. For a skier it can occur when skiing in the so-called “back-seat” position when one’s weight is too far back on one’s heels. Skiing in this positions puts huge stresses on the quadriceps muscle and can literally pull one’s ACL apart when the knees are absorbing the shocks navigating through the bumps.
In many cases, there is shifting sensation and frequently an audible or felt “pop” as the knee gives way. There is usually a moderate amount of pain and an inability to effectively continue the activity. Over the next several hours the knee will usually swell and walking may become difficult.
The disability is usually severe enough that the person seeks out medical advice. An orthopedic surgeon can usually identify which ligaments are injured and MRI scans are usually done to confirm the diagnosis and determine if any additional injury might have occurred.
The most frequent question after an ACL tear is “Will I need surgery?” The answer to that question varies from person to person and the criterion we use has to do with an individual’s normal level of activity, their expectations, the presence of associated injuries and the amount of abnormal knee laxity. Certainly, a person who wants to return to competitive sports is more likely to require surgery than one who is relatively sedentary. Statistically, though, for high level athletes who decline ACL surgery, only 4% are able to return to their pre-injury level of performance at two years.
For those that choose surgery, there are a number of surgical approaches. Years of experience have shown that simply stitching the ligament together is rarely successful. Therefore current techniques involve reconstructing the ACL by building a new ligament out of tissue harvested either from another tendon or ligament around the individual’s own knee or from an organ donor.During the operation the graft tissue is passed through drill holes in the thigh bone and shin bone and anchored in place to create a new ACL. Over time, the bone tunnels fill in, the graft matures and it becomes a new ligament in one’s knee.
The overall success rate for ACL surgery is very good with most studies confirming that over 90% of athletes have been able to return to their individual sports without symptoms of instability.
Tears of the medial or lateral meniscus are common sports injuries and every year, at least 1 million Americans will injure their medial or lateral meniscus. Twisting forces are usually responsible for these tears and as a person ages the forces that are required to produce a tear in this cartilage are typically less than when the person is younger.
Meniscus tears often cause pain and swelling and may cause the knee to “give-way” or “lock”. Arthroscopic surgery is usually required to deal with a torn meniscus and if the meniscus can be repaired and therefore preserved, the knee is better off. Tears that are most suitable for repair are the ones that occur in the outer one third of the meniscus as it is only here that there is a blood supply to provide a healing environment. In contrast, when the meniscus tear occurs in the non-vascular zone, we instead trim back the frayed and damaged portion. In doing this, the portion that is being pinched and caught and causing pain is simply removed. The recovery is usually rapid since this is truly minimally invasive surgery done with an Arthroscope (telescope) through two or three small incisions around the front of the knee. Most patients are functioning well by six weeks.
Arthritic Conditions and Total Joint Replacement Options – refer to total joint section