Anterior Cruciate Ligament Repair

Definition

The anterior cruciate ligament (ACL) is one of the main stabilizing ligaments in the knee. A tear of the ligament can be partial or complete. It is a serious injury leading to destabilization of the knee.

Description

Ligaments are strong, leather-like fibers of connective tissue that enclose a joint. They can be stretched (sprained), or partially or completely torn.

A patient can tear one or more ligaments, or ligaments and menisci simultaneously. The degree of damage depends on the direction and magnitude of the injuring force.

The most common combination is injury to the medial collateral and the anterior cruciate ligaments, often seen in football after a player is hit from the side. The high incidence of knee injuries from this mechanism led to the abolition of the "crack-back" block in American football.

Most ligament tears are caused by severe forces, but the anterior cruciate ligament (ACL) may be damaged by moderate forces such as landing from a jump. An isolated tear of the anterior cruciate ligament is the most common ligament injury.

If the force to the side of the knee is more severe, or if you are rotating your knee when you are hit, then the ACL may be stretched or torn. The most severe ruptures are caused not by trauma but usually by a heavy athlete, such as a football lineman, running and then planting his foot and turning 90 degrees to go upfield. This twisting can cause a complete ACL rupture.

If the ACL ruptures, a loud pop may be heard. A person will feel pain and instability in the knee. The knee will swell up rapidly because the ACL bleeds quickly when injured. Any ACL injury causes symptoms profound enough for one to seek professional help.

A ligament tear causes a hemorrhage, producing a swollen, painful joint that will not bear weight. A chronic tear causes symptoms only during vigorous activities such as sports, usually in the form of giving way. Over a period of time, this can damage the menisci and cartilage, leading eventually to degenerative wear and tear osteoarthritis.

Within two weeks of the injury, a simple sprain or partial tear are treated in a plaster cast (groin to toes) for four to six weeks. This is followed by approximately six weeks of physiotherapy and a return to sports in three to six months.

Non-surgical treatment of a chronic tear depends on the patient's age and needs. The low demand or unathletic person may be content to decrease activities so that the knee never gives way. More athletic individuals may be able to cope by wearing a brace to stabilize the knee during sports.

Procedure

An acute complete tear of one or more ligaments usually requires surgery. The torn ligaments are reconstructed and the patient starts to exercise to begin movement of the knee immediately. Sometimes it is impossible to repair the ligament, because it is too shredded or has a poor blood supply. This applies particularly to chronic tear. Under these circumstances a new ligament must be constructed using the patient's own tissues (tendons or connective tissue), or by using synthetic materials.

After surgery for a torn ligament, the leg is in cast from groin to toes, with the knee bent, for about five weeks. When the cast is removed, the patient gradually straightens the knee over several weeks during a course of physiotherapy. Once the knee is straightened, the patient begins to take the weight on the leg with the help of crutches. The patient starts full weight-bearing about three months after surgery, but physiotherapy continues for four to six months, followed by a return to sports in nine months to a year.

Modern methods of repair through the arthroscope plus new ideas on rehabilitation, such as beginning exercises immediately after surgery, have dropped recovery time from 12 to 15 months to 6 to 7 months. Even so, rehabilitation is a major undertaking.

There are also rehabilitation programs for a partially torn ACL. Done under a physical therapist's guidance, they center on the use of isokinetic exercise machines, which are more efficient than regular free weights or the weight machines in gyms.

A highly competitive athlete performing at an international level may or may not reach former performance levels after a major ligament repair. For example, it is unlikely that a running halfback in football could return to his pre-injury performance.

Questions to Ask Your Doctor

How serious is the injury?

Is the ligament stretched or totally torn?

Can the ligament be repaired?

Is a cast a likely option?

Will surgery be required?

Is arthroscopic surgery possible?

How long will rehabilitation take?

What type of rehabilitation will be prescribed?