ACL Reconstruction
Physiology
When a severe twisting of the knee occurs, one or both of these ligaments (ACL and PCL) may become stretched, or even torn. This twisting of the knee may be related to a contact injury (such as might occur in football), or even a non-contact injury. Some patients report of hearing a “pop” or “snap” when the injury occurred. Following the injury, the injured knee joint may swell and feel like it may “give way” when weight is applied.
A tear in the anterior cruciate ligament (ACL) is one of the most common knee injuries that may occur to a recreational, amateur, or professional athlete. This injury may result from twisting the knee too far in one direction, or by a sudden and forceful change in direction as may occur during football, soccer, skiing, basketball, racquetball, or tennis. Frequently, the injury occurs in those sports that require the foot to be planted in one spot, and the body to suddenly change direction or make a lateral movement.
Surgical Technique
This anterior cruciate ligament is a thick fibrous band that connects the femur (the thigh bone) with the tibia (shin bone). If the ACL is completely torn, the knee becomes unstable. Because long-term instability may lead to early arthritis of the knee, a proper diagnosis is necessary to obtain the best possible outcome. By recognizing the instability and reconstructing the ACL, the chance of degenerative changes in the joint are reduced. A small percentage of people may be able to function with a torn ACL; however, this usually requires modification of activity.
Reconstruction of the knee joint following complete ACL rupturing, may require surgery to replace the stabilizing effect of the original ACL.
During surgery, a bone and soft tissue graft is taken (or harvested) from the anterior knee. A small portion of bone is taken from both the patella (knee cap) and tibia (shin bone). The drawing on the left depicts the location of this graft site. The bone grafts are connected to each other by a piece of strong patellar tendon. This graft with its three components will now serve as the new ACL ligament.
During surgery the one-piece bone and tendon graft (as seen on the left) will be surgically anchored inside of the knee joint in a location similar to the patient's original anterior cruciate ligament. This will help insure that the knee joint will have stability postoperatively. During surgery the bone tunnels (holes) within the tibia and femur are created arthroscopically with small skin incisions, creating bone pathways for the insertion of the new tendon graft.
Prior to placement of the ACL tendon graft, it is prepared by attaching a metallic Endobutton to the graft's proximal end. This button will be inserted into the femur providing a secure proximal attachment to the ACL graft. Additionally, a strong tensioning suture is attached to the graft's distal end. During surgery, this suture is used to apply the appropriate amount of tension to the graft within the knee.
The tendon graft itself is positioned by arthroscopic technique, providing a secure reconstruction both in the femur (with Endobutton stabilization) and in the tibia (with interference screw fixation). By using arthroscopic technique, Dr. Ahlfeld is able to surgically reconstruct the ACL with minimal skin incisions. The small Endobutton allows the ACL graft to be inserted and held securely within the femur.
Following the graft placement into the femur, the graft is tensioned at the tibia below the knee joint. A single absorbable interference screw is inserted into the tibial drill hole securing the bone segment to the cancellous bone within the tibia.
The proper placement and alignment of this graft insures that the reconstructed knee will function as it did in its pre-injury condition. Care is taken to place the ligament graft into the correct anatomical position, so that optimal knee joint function and stability will be achieved. Once healed, and following rehabilitation, the graft's function will closely match that of the original ACL.
The original incision on the patellar tendon is closed with sutures. Recovery time for this type of surgery may take several months.
Because each injury and each patient's knee may be different, an individually tailored, post-operative rehabilitation program is designed to assure each patient of the best outcome.
Dr. Ahlfeld is a pioneer in this type of ACL reconstruction and has been using this technique successfully in athletes for many years.
If you should have a question or concern about anterior cruciate ligament (ACL) reconstruction, or any other knee problem, please call our office.