What is an ACL reconstruction?
An ACL reconstruction involves taking a tendon from somewhere else and using it as a graft to replace (or reconstruct) the torn ACL, providing the same knee stability as a real ACL. The tendon may come from either the patient undergoing surgery (an autograft tendon) or from a cadaver (an allograft tendon).
Why should the ACL be reconstructed?
Stability is the main reason the ACL should be reconstructed. This is necessary for two reasons.
- First, the ACL is needed for knee stability during sporting activities that involve cutting and pivoting.
- The second and most important reason to reconstruct the ACL is that ACL deficiency predisposes the patient to injury of other crucial knee structures. In other words, the only purpose of the ACL is to provide knee stability in order to prevent meniscal and cartilage injury.
These types of knee injuries can eventually lead to degenerative arthritis of the knee joint.
Younger and/or active patients who are unwilling, or unable, to modify their activities benefit from ACL surgery, as do patients with instability while performing non-strenuous activities or activities of daily living. The majority of patients with injuries to multiple knee ligaments have better outcomes with operative treatment.
What is involved in an ACL reconstruction?
Re-creating the anatomy of the original ACL involves first removing the damaged ACL and next drilling tunnels in the both the tibia and the femur. These tunnels need to be in the exact orientation of the natural ACL, in order to ensure that the newly placed graft will act in the same manner as the original ACL. The tunnels serve to place the ACL graft in the proper orientation and as a point of fixation of the graft to bone.
Initially, after a new ACL graft has been placed in the correct position, i.e., spanning the inside of the knee joint and inside tunnels on both sides of the knee joint, the graft must be fixed in position.
This is typically accomplished with screws or some other sturdy device. Regardless of the type of fixation used, the device plays only a temporary role until the graft has healed to the insides of the tunnels. Once this is accomplished, the initial fixation device no longer serves a purpose, because the ultimate strength comes from the soft tissue graft healing to the surrounding bone tunnels. This process takes several months to be complete.
Are all ACL reconstructions done arthroscopically?
To some extent, yes. In some circumstances, such as revision cases or cases involving simultaneous multiple ligament reconstructions, portions of the procedures need to be performed open. However, for a first-time ACL reconstruction, the surgery is almost always done arthroscopically, where the Wisconsin Bone & Joint surgeon performs the reconstruction while visualizing surgery through the arthroscope.
Are there different types of arthroscopic ACL reconstructions?
Yes, there are two main types of arthroscopic ACL reconstructions: the single incision and the double incision technique. Both surgeries are fundamentally the same and produce the same results. The difference exists in how a surgeon drills the tunnel in the femur and the number incisions in the knee.
Is ACL surgery out-patient or in-patient surgery?
ACL reconstructions can be performed in either setting, but the majority of cases currently performed today are in the out-patient setting.
What type of anesthesia is used for the procedure?
Usually a general anesthesia is used, but because of the short duration of the surgery (usually one hour or less), the patient is not completely asleep. A regional (or nerve block) is also used in addition to help with post-operative pain. Spinal anesthesia is also an option. The choice is usually a decision made between the anesthesia physician and the patient.