Anterior Cruciate Ligament Surgery

What is the anterior cruciate ligament?

The anterior cruciate ligament (ACL) is one of the structures that connect the femur and tibia bones in the knee joint. This ligament is crucial for the normal functioning of the knee and serves as the primary structure that prevents abnormal forward displacement of the tibia bone.

How does an ACL injury occur?

An ACL injury typically occurs during a sudden twisting motion on a fixed foot. In rare cases, direct blows to the knee, such as in traffic accidents, falls from heights, or industrial accidents, can also result in ACL injuries. In such cases, injuries to the posterior cruciate ligament, collateral ligaments, and meniscus may also occur.

What are the symptoms of an ACL injury?

During an ACL injury, patients experience a sudden popping sensation accompanied by severe pain. They are often unable to continue participating in sports activities. Following the ligament tear, swelling occurs in the knee due to internal bleeding. In some cases, the bleeding can be significant, requiring drainage of the knee hematoma. Typically, patients experience pain, limping, and limited range of motion in the knee after the injury, necessitating the use of crutches. Once the pain and swelling in the knee decrease, they can return to daily activities; however, recurrent episodes of instability and giving way of the knee may occur during sudden movements or jumping. Patients with ACL tears can engage in low-impact activities like swimming and cycling, but high-impact sports such as football, basketball, handball, volleyball, and skiing involving jumping, twisting, and acceleration cannot be performed at a competitive level without an intact ACL. If an athlete wishes to continue participating in these sports without an ACL, the risk of further injuries and increased damage to the knee is significantly high.

How should first aid be administered on the sidelines for an ACL injury?

An ACL tear should be considered in any athlete who experiences severe pain and swelling following a sudden twisting motion of the knee. Immediate application of ice and compression with an elastic bandage can help reduce swelling and pain. The athlete should not be allowed to return to the game. They should avoid putting weight on the affected leg, leave the field, and use crutches until a definitive diagnosis is made.

How should first aid be administered on the sidelines for a meniscus injury?

In any athlete experiencing severe pain following a sudden twisting motion of the knee, a meniscus tear and ligament injury should be considered. Immediate application of ice and compression with an elastic bandage can help reduce swelling and pain. The athlete should not be allowed to return to the game. They should avoid putting weight on the affected leg, leave the field, and use crutches until a definitive diagnosis is made.

How is an ACL injury diagnosed?

Diagnosis of an ACL tear begins with a detailed description of the injury mechanism. This is followed by a careful physical examination. With just this history and examination, the diagnosis of an ACL tear can be made with an accuracy rate of over 90%. X-rays are usually normal in ACL injuries. Magnetic resonance imaging (MRI) has a diagnostic accuracy rate of over 90% for ACL tears. It can also identify accompanying meniscus, collateral ligament, cartilage injuries, and bone edema. However, in rare cases, an MRI can be misleading, showing a preserved appearance of the ligament despite a complete functional tear. Therefore, when deciding on treatment, the MRI should not be the sole determining factor, and the findings from the physical examination and patient history should also be taken into account.

What are the treatment options for anterior cruciate ligament (ACL) injury?

In young individuals, athletes, or those with an active lifestyle, surgical treatment is recommended for anterior cruciate ligament (ACL) injury. However, in older individuals who are not highly active, do not participate in sports, and do not experience symptoms such as instability or giving way in the knee during daily activities, non-surgical treatment may be considered. Non-surgical treatment options include muscle strengthening programs to reduce feelings of instability and the use of protective knee braces during high-demand sports. However, in cases of severe injury, neither of these measures can prevent the knee from dislocating, and additional injuries may occur.

What are the goals of ACL surgery?

The goals of ACL surgery in individuals with ACL injury are to eliminate feelings of instability and insecurity in the knee, and to achieve a knee that can bear weight safely during sports or demanding activities. If the meniscus is not damaged during the initial injury, the surgery aims to preserve the menisci and repair any repairable meniscus tears to prevent future wear and tear in the knee. Another goal of the surgery is to return athletes to their pre-injury sports level and prevent the occurrence of new knee injuries.

How is ACL surgery performed?

If the ACL is torn by pulling a piece of bone where it attaches, the detached bone fragment is reattached. This condition, which is more common in children, can be repaired using screws or sutures. This procedure is mostly performed arthroscopically, but in rare cases, open surgery may be necessary. In adults, the ACL is usually torn by the separation and fragmentation of its fibers. The torn ligament, in the form of frayed tissue, cannot be repaired, and it needs to be reconstructed using a new tissue during surgery. The most commonly used tissue for ACL reconstruction is the tendons located at the back of the knee, known as the hamstring tendons. Hamstring tendons do not have bone blocks at their ends. The second most commonly used tissue is the patellar tendon, which is taken with bone blocks on both ends from the front of the knee. In some cases, sterilized tissues obtained from cadavers, known as allografts, can be used. Allografts are generally preferred in cases where multiple ligaments are injured and the patient’s own tissues are insufficient, in cases where previous surgeries have been performed using the patient’s own tissues, and in very young children.

Depending on the strength of the repair and the presence of other interventions performed within the joint (e.g., ACL surgery), you may need to use crutches for a few weeks and avoid squatting after ACL surgery. The return to sports can vary between 6 weeks to 6 months. The success rates of meniscus repair vary depending on the type of tear and the surgical technique used, but they range from 70% to 95%. Despite the repair, the meniscus may not heal or may re-tear. In other words, in 5-30% of patients who underwent meniscus repair, a second surgery may be necessary. Although the failure rate may seem high, considering the wear and tear that would occur in the knee without menisci, this risk is acceptable. If the repair fails, a simple procedure can be performed to remove the torn part of the meniscus.

What are the steps of anterior cruciate ligament (ACL) surgery?

The first step is obtaining the tissue that will be used for ligament repair, known as a graft. Then, a knee arthroscopy is performed to evaluate other structures within the joint. If there is any injury to the meniscus or articular cartilage, the necessary interventions are carried out. Afterward, tunnels are created in the bones of the knee to prepare the path for the new ligament. The graft is passed through these tunnels and secured within the bone tunnels at an appropriate tension. This can be achieved using metal or absorbable screws, cross pins, or U-shaped staples. These screws and staples that hold the ligament in place can remain in the body indefinitely as long as they do not cause any discomfort and do not need to be removed. The surgery can take between 40 minutes to 1 hour. To drain the accumulated blood within the knee joint, a thin plastic tube called a drain is inserted, which is usually removed during the dressing change 24 hours after the surgery.

What happens after ACL surgery?

The typical hospital stay after ACL surgery is usually 2 nights. Once the effects of anesthesia wear off, it is possible to get up with the help of crutches, but weight-bearing is generally avoided on the side where the drain is present in order to drain the blood from the knee. The next day, after the drain is removed from the knee, the patient is assisted to get up with the aid of crutches and is encouraged to bear weight on both sides as tolerated and start walking. Physical therapy exercises are initiated, aiming to achieve a knee flexion of 90 degrees. In the first 3 weeks after surgery, walking with full weight-bearing using both crutches is allowed, followed by 3 weeks of walking with full weight-bearing using a single crutch. Dressing changes are usually done every 3 days, and stitches are removed 15 days after the surgery. It is necessary to avoid contact of the surgical area with water until the stitches are removed. During the discharge from the hospital, the patient must regularly take the medications prescribed by the doctor. Within three weeks after surgery, full range of motion should be regained. If the exercises performed by the patient are not sufficient, rehabilitation can be carried out under the supervision of a physiotherapist. It takes 6-8 weeks for the graft tissue to fuse to the bone tunnels. After this period, normal walking and driving become possible. The complete maturation and strengthening of the implanted tissue takes about a year, but sports activities can typically be resumed after the 5th month.

What are the success rates of ACL surgery?

The reported success rates of ACL surgery in our country and worldwide range between 80% and 90%. However, in some patients (10-20%), satisfactory results may not be achieved due to technical issues, new injuries, or the newly implanted tissue not maturing and strengthening as a new ligament. In some of these cases, revision surgery may be necessary. The factors that significantly affect the success of the surgery are the surgeon’s interest, experience, and the postoperative rehabilitation program applied. Therefore, in almost every patient, appropriate rehabilitation program and ACL exercises should be initiated after the surgery.

What are the possible complications after surgery?

Deep vein thrombosis: It is the formation of a blockage in the deep veins of the leg. There is a risk of occurrence after any surgery related to the lower extremity, and prolonged surgery, genetic predisposition, and advanced age increase the risk. To minimize this risk, all patients receive short- or long-term anticoagulant medication, known as blood thinners, according to their individual risk profile after the surgery. They are also provided with anti-emb

olism stockings, and early mobilization is encouraged.

Infection: Although infection is very rare in arthroscopic cases, it can occur. Just like in any open surgeries, extreme attention to sterility is required in these operations. To further reduce the risk of infection, antibiotic prophylaxis should be used. In some cases, a short course of antibiotics may be prescribed after the surgery, at the discretion of the physician.

Joint Stiffness: The risk of developing joint stiffness after arthroscopic cases is very low. However, if ACL surgery is performed after the first 3 weeks of knee injury, this risk may slightly increase. Early mobilization after surgery helps to reduce this risk.

Graft Impingement: If the location of the bone tunnels created during ACL surgery is not appropriate, the implanted ligament may get impinged within the knee during movements, causing restricted motion, pain, and swelling. This risk is minimized with the surgeon’s experience. When graft impingement is diagnosed, revision surgery is often necessary.