ANTERIOR CRUCIATE LIGAMENT (ACL) RECONSTRUCTION
The anterior cruciate ligament (ACL) sits in the middle of the knee and runs from the end of the femur (thigh bone) to the top of the tibia (shin bone). The primary role of the ACL is to provide knee stability. Patients who sustain a low grade ACL injury (Grade I or II) in which the ACL is still functional can be treated with a specific physical therapy program to focus on hip, core, and knee strengthening. In those patients who sustain a Grade III tear with instability of the knee, many patients, particularly young and more athletic individuals, require surgical intervention.
The goal of ACL surgery is to stabilize the knee by replacing the torn tissue with new, healthy tissue from a donor (allograft tissue) or from the patient’s own body (autograft). The new tissue must be placed in the right position in the knee and must be tensioned appropriately to restore stability to the knee. Surgical techniques have changed tremendously over the last 10-15 years. In the 1990s and early 2000s, ACL reconstruction grafts were placed centrally in the tibia (shin bone) and femur (thigh bone). However, research has demonstrated that many of these patients re-tore their ACL and developed unstable knees. Orthopaedic surgeons now have a much better understanding of the anatomy of the “footprint” of the ACL and most sports surgeons now use an “Independent Tunnel” technique to reconstruct the ACL and restore stability. Dr. Keller prefers this “Independent Tunnel” technique.
Multiple grafts are available to reconstruct the ACL. Allografts (taken from a cadaver) include achilles tendon, patellar tendon, and hamstring, among others. Autografts (taken from the patient) include patellar tendon, hamstring, and quadriceps, among others. Generally speaking, Dr. Keller prefers using autograft for patients under the age of 30, as re-tear rates are lower with autograft tissue.
Following surgery, patients are placed in a brace that is locked straight. In those patients who only have ACL surgery, Dr. Keller encourages patients to walk with the brace in place. When the patient is sitting or lying down, Dr. Keller encourages knee range of motion exercises with the brace removed. Dr. Keller also recommends intermittent icing and straight leg raises to strengthen the quadriceps muscles. Dr. Keller recommends starting physical therapy one week after surgery. Physical therapy focuses on reducing swelling in the knee, restoring full range of motion, and eventually, restoring strength to the knee with particular emphasis placed on the quadriceps. Dr. Keller recommends advancing the physical therapy program to cutting, pivoting, and sport-specific activities only after the patient has achieved certain goals (for example, appropriate quadriceps strength, appropriate range of motion, etc.). Most patients start sport-specific training approximately 4-6 months after surgery. Most patients return to competitive sports approximately 6-9 months after surgery. It is very important to follow the rehabilitation process carefully to achieve the best outcome.