Author: Mahdi Mohammed, Y12
An ACL injury is a tear or sprain of the anterior cruciate ligament (ACL) — one of the major ligaments in your knee. The ACL is one of the key ligaments that help stabilize your knee joint. The ACL connects your thighbone (femur) to your shinbone (tibia). Its vital function of directing the tibia in its correct path from the end of the femur maintains joint stability. Therefore, ACL injuries most commonly occur during sports that involve sudden stops or changes in direction, jumping and landing — such as soccer, basketball, football and downhill skiing. While they are common with professional and recreational athletes, there are approximately 100,000 to 200,000 ACL ruptures per year in the US. The mechanism of ACL tears are quite similar to other ligaments injuries as the tear can occur with both contact and non-contact maneuvers. 70 percent of injuries are non-contact and occur when the athlete is attempting to change directions, slow down or land from a jump. In contact injuries, a direct blow can cause the knee to hyperextend or bend inward. Furthermore, there are numerous factors that increase the risk of ACL injuries, some of them include: Being female, poor conditioning, wearing footwear that doesn’t fit and playing on artificial turf surfaces. Signs and symptoms of an ACL injury tend to include: A loud pop or a popping sensation in the knee, severe pain or inability to continue activity, rapid swelling in the knee, loss of range of motion and a feeling of instability with weight bearing. To determine an ACL tear, there is a test called the Lachman test, which checks the displacement of the tibia on the femur with the knee flexed 30 degrees. The physician also will determine if there is a solid, soft or no end-point of the ligament when doing the test. There are other tests as well that can be done when the swelling subsides called the Anterior Drawer Test and the Pivot Shift Test. MRI scans are routinely done, not only to confirm the diagnosis, but to rule out other injuries of the knee.
Treatments for ACL injuries depends on the severity of the injuries. Treatments for minor injuries usually consist of first aid at the site of injury. This involves putting ice on your knee, elevating your leg above your heart to minimize swelling by allowing fluid to drain away from the area as well as using anti-inflammatory drugs which can help reduce swelling and pain. A partial tear of the ACL has a recovery period usually at least 3 months with a knee brace. However some patients with partial ACL tears may still have instability symptoms. This is when surgical treatments are considered. This is because the ACL cannot heal on its own if the tear is complete as there is no blood supply to this ligament. Once a devastating and career-ending injury for athletes, is now amenable to surgical reconstruction. ACL reconstructions were developed due to high failure rates for ACL repairs. ACL repairs in the past involved reattaching the ligament to the bone with stapes or other surgical devices. Nowadays, most ACL reconstructions are now performed all-arthroscopically or arthroscopically –assisted with a small incision of about 3cm. These incisions have to occur on the backside of the knee as it is the only way to insert the graft as the PCL is in front of the ACL due to the X shape. These minimally invasive techniques allow a graft (a piece of tendon) to be placed into the knee to replace the torn ACL. The grafts are secured into sockets created in the thigh bone (femur) and shin bone (tibia) in very precise positions. The grafts can be secured with many different types of metal, plastic or bio-absorbable implants to allow for aggressive postoperative rehabilitation. A complication of this surgery is that it requires to cut through the intracapsular ligaments which are one of the strongest ligaments in the body as you need to get to the ACL through these ligaments. The operation will weaken these ligaments which in hand weakens the outside of the knee. Another complication is if the surgery is performed too late. Damage to the meniscus and articular cartilage may result from persistent instability which leads chronic ACL deficiency, where a surgeon may not be able to fix all of the joint damage. It usually takes six to nine months to return to full activity after ACL reconstructive surgery. During this time, physical therapy has to be undertaken to allow the patients to increase their range of motion, decrease swelling and help them regain control and strength of their muscles more quickly. A fully functioning ACL is attainable 90% of the time with careful surgical technique and appropriate rehabilitation.
This is boring ahahahah