ACL Injury: Operative Procedure

Before any surgical treatment, the patient is usually sent to physical therapy. Patients who have a stiff, swollen knee lacking full range of motion at the time of ACL surgery may have significant problems regaining their motion after surgery It usually takes three or more weeks from the time of injury to achieve full range of motion. It is also recommended that some ligament injuries be braced and allowed to heal prior to ACL surgery.

The patient, the surgeon and the anesthesiologist select the anesthesia used for surgery. Patients may benefit from an anesthetic block of the nerves of the leg to decrease postoperative pain. The surgery usually begins with an examination of the patient's knee while the patient is relaxed due the effects of anesthesia. This final examination is used to verify that the ACL is torn and also to check for looseness of other knee ligaments that may need to be repaired during surgery or addressed postoperatively. If the physical exam strongly suggests the ACL is torn, the selected tendon is harvested (for an autograft) or thawed (for an allograft) and the graft is prepared to the correct size for the patient.

After the graft has been prepared, the surgeon places an arthroscope into the joint. Small (one-centimeter) incisions called portals are made in the front of the knee to insert the arthroscope and instruments and the surgeon examines the condition of the knee.

Meniscus and cartilage injuries are trimmed or repaired and the torn ACL stump is then removed. In the most common ACL reconstruction technique, bone tunnels are drilled into the tibia and the femur to place the ACL graft in almost the same position as the torn ACL. A long needle is then passed through the tunnel of the tibia, up through the femoral tunnel, and then out through the skin of the thigh. The sutures of the graft are placed through the eye of the needle and the graft is pulled into position up through the tibial tunnel and then up into the femoral tunnel. The graft is held under tension as it is fixed in place using interference screws, spiked washers, posts or staples. The devices used to hold the graft in place are generally not removed. Variations on this surgical technique include the "two-incision" and "over-the-top" types of ACL reconstructions, which may be used because of the preference of the surgeon or special circumstances (revision ACL reconstruction, open growth plates).

Before the surgery is complete, the surgeon will probe the graft to make sure it has good tension , verify that the knee has full range of motion and perform tests such as the Lachman's test to assess graft stability. The skin is closed and dressings (and perhaps a postoperative brace and cold therapy device, depending on surgeon preference) are applied. The patient will usually go home on the same day of the surgery.