By: Steve Siwy for Knee1There was a time when a torn anterior cruciate ligament (ACL) meant the end of an athlete’s career. Star Chicago Bears running back Gayle Sayers, for example, had what was already a hall-of-fame career cut short by a nagging ACL injury. Now, advances in ACL surgery have enabled many athletes to return to playing more quickly, and with less chance of reinjury – benefits which are good news even for those patients who don’t happen to make a living playing professional sports.
The ACL is a ligament in the knee that connects the tibia (shinbone) to the femur (the thighbone, the largest in the body), and stabilizes the joint, keeping the shin from sliding forward. The knee can still function without an ACL, and the leg still walked upon, but for athletes or anyone else likely to place more stress upon the joint than just walking on it, regaining full performance usually requires that the ACL be repaired with surgery.
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How will you Benefit?
1) New focus on immediate, vigorous rehabilitation where patient may be able to exercise the day after surgery
2) Bioabsorbable screws instead of metal are easier to remove if second revision surgery is necessary
3) Minimally-invasive surgery (i.e. arthroscopy) with sometimes merely one incision
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Usually, surgery involves replacing the torn ACL altogether. For a replacement ligament, the surgeon can use an autograft from the patient’s own body, or an allograft taken from a cadaver. The tissue used is usually either a strip of hamstring tendon, or of patellar tendon from under the kneecap. The patellar tendon makes a stronger graft, but the procedure to harvest it is more invasive than that used to harvest a strip of the hamstring (at least in the case of an autograft).
The replacement tendon is threaded through a tunnel in the patient’s tibia, the intercondylar space in the knee joint, and then through another tunnel in the femur, and affixed at either end with screws, staples, or other fastenings. The notch in the femoral condyle is also expanded via “notch-plasty” to allow for proper placement and range of motion of the new graft. (The “condyles” are the protrusions at the ends of each bone near the joint. The word comes from Latin via French, and literally means “knuckle.”)
As with many other kinds of surgery, one of the reasons for the increased success of ACL reconstruction in recent years is that the surgery itself has become less invasive. It is now performed arthroscopically, with tiny instruments and a camera inserted into the knee through small incisions. As little as a single incision may be used, though there will be more incisions required to harvest tissue for the graft, for instance, or if the doctor prefers to use one or more additional incisions to position the graft accurately.
Improved methods of affixing the graft to the bones have also improved the outlook for patients undergoing ACL reconstruction. Studies have shown that the site of the graft’s fixation is the most common point at which failure occurs after surgery. Among the tools now available for fixing the graft are “bioabsorbable” interference screws, which instead of metal are made of material that can be reabsorbed by the body over time, after the graft has knitted itself to the bone. Metal screws can be difficult to remove if a second, “revision” surgery is needed later on, and can also interfere with magnetic resonance imaging (MRI) scans.
With the array of new techniques available, and a new focus on immediate, vigorous rehabilitation (the patient may begin exercising the joint the day after surgery, and will begin putting weight on it as soon as possible), some patients can return to near-normal function within a few months. Athletes usually have to wait up to a year, sometimes longer, to achieve levels near their former peak performance. As Dr. John Uribe, who performed ACL surgery last year on Willis McGahee of the Buffalo Bills, told the Buffalo News, "You're taking tendon from one part of the body and inserting it in another. That ligament has to develop a blood supply. It has to incorporate itself into the body. And that takes quite a while." For what used to be a career-ending injury, some athletes might consider it a result worth waiting for.
