The ACL is one of the four main stabilizing ligaments in the knee joint. The others include the posterior cruciate ligament (PCL), medial collateral ligament (MCL) and lateral collateral ligament (LCL). The PCL works with the ACL. It prevents the tibia from sliding backwards under the femur. The MCL runs along the inner part (side) of the knee and prevents the knee from bending inward. The LCL runs along the outer part of the knee and prevents the knee from bending outward.
The ACL attaches to the femur at the back of the joint and passes down through the knee joint to the front of the flat upper surface of the tibia.
It passes across the knee joint in a diagonal direction and the PCL passes it in the opposite direction, forming a crossing pattern between the two, hence the name cruciate ligaments. The role of the ACL is to prevent forward movement of the tibia from underneath the femur. The PCL prevents movement of the tibia in a backwards direction.
Together these ligaments are extremely important for the stability of the knee joint, especially in contact sports and those that involve fast cutting and changing directions quickly, twisting and pivoting.
By definition, a knee sprain is an injury to a knee ligament. A sprain is a joint injury that causes a stretch or a tear in a ligament, and ligaments function to connect bone to bone. The ACL connects the thigh bone to the shin bone. ACL sprains are graded I, II, or III depending on their severity: grade I sprain: pain with minimal damage to the ligaments, grade II sprain: more ligament damage and mild looseness of the joint, grade III sprain: the ligament is completely torn and the joint is very loose or unstable.
Causes of Injury: ACL sprains may be due to contact or non-contact injuries. A blow to the side of the knee, which can occur during a football tackle, may result in an ACL sprain or tear. Coming to a quick stop, combined with a change in direction while running, pivoting, landing from a jump or hyperextending the knee joint also can cause injury. The ACL is frequently injured in forced twisting motions of the knee. Also, it sometimes occurs when the thigh bone is forcefully pushed across the shin bone, such as with a sudden stop while you are running or a sudden transfer of weight while you are skiing.
Nevertheless, ACL injuries can occur in any sport if the knee undergoes acceleration and rotational movements. Women are more likely to have an ACL tear than men. The cause for this is not completely understood, but it may be due to differences in anatomy and muscle function. Adults usually tear their ACL in the middle of the ligament or pull the ligament off the femur bone. These injuries do not heal by themselves and require reconstructive surgery. Children are more likely to pull off their ACL with a piece of bone still attached. These injuries may heal by themselves, or they may require surgery to fix the bone.
Inactive people and some older adults who have weak leg muscles may injure their knees during normal daily activities. But they usually injure bones, not ligaments. If you have torn your ACL in an injury that occurred months or years ago and you have not had reconstructive surgery, you may have the feeling that the knee is unstable and giving way during twisting or pivoting movements. Some people are able to live and function normally with a torn ACL; however, most people complain that their knee is unstable and may give out with any type of physical activity. Prevention:
Most injuries to the ACL occur during accidents that are not preventable. However, you may be able to avoid these injuries by having strong thigh and hamstring muscles and maintaining a good stretching routine. In activities that require cutting, make sure you keep your body moving in the same direction and come to a stop before initiating a change in movement or direction. When you are vertically or horizontally jumping, make sure you catch your jump by supporting the knees through flexion of the quadriceps and gluteus maximus, and use the arms to help balance out the weight transfer.
Athletes can reduce their risk of ACL injuries by performing training drills that require balance, power and agility. Adding plyometric exercises, such as jumping, and balance drills helps improve neuromuscular conditioning and muscular reactions, and ultimately shows a decrease in the risk of ACL injury. Many team physicians now routinely recommend an ACL conditioning program, especially for female athletes. The Santa Monica ACL Prevention Project developed an ACL Injury Prevention Program specifically for female soccer players.
This 15-minute training program incorporates balance, agility and performance drills into the warm up phase of training and practice. Phases of the ACL Injury Prevention Program should be performed at least 2-3 times per week during the season and includes warm up, stretching, strengthening, plyometrics, agility drills, and cool down. Signs and Symptoms: There is usually a loud, painful pop when the joint is first injured. This is often followed by a lot of swelling of the knee within the first several hours after the injury.
This swelling is called an effusion and is made up of blood in the knee joint. A feeling of initial instability is common, but may later be covered by extensive swelling. A torn ACL is extremely painful, specifically, immediately after sustaining the injury. Restricted movement, inability to fully straighten the leg, and possible widespread tenderness are all positive signs of a torn ACL. A good rule of thumb for these injuries is if you receive a blow to the knee and the pain is on the same side of the knee that was hit, it is probably just a bruise, and the pain will go away rapidly.
If the pain is on the opposite side of the knee, consider this a serious injury that needs treatment. The anterior drawer and Lachman’s tests are great indicators of a torn ACL. The anterior drawer test is initiated with the knee flexed to approximately 80°, complete relaxation of the hamstrings is achieved by hamstring palpation. Next, with the foot stabilized and in neutral position, a firm grip on the proximal tibia is performed. Then, an anterior force is applied to the proximal tibia with a gentle to-and-fro motion to assess for increased translation compared to the normal contralateral knee.
The Lachman’s test consists of one hand securely stabilizing the distal femur while the other hand firmly grasps the proximal tibia. A gentle anterior translation force is applied to the proximal tibia. The examiner assesses for a firm, solid, or soft endpoint. Treatment and Rehab: The immediate treatment for a sprained knee is the standard RICE formula. This is an acronym for Rest, Ice, Compression, and Elevation. These steps will help reduce swelling and pain, and speed the healing process. Rest the knee while it aches and ice it several times a day.
Wrap it in an elastic bandage in between icings, and keep it elevated as much as possible. After it is determined that an additional medical advice from a physician is necessary, the initial evaluation includes a complete history of the injury, how it happened, the type of movement that caused the injury, whether the individual heard a pop, where and how badly the knee hurts, and the degree of stability that the knee feels. Treatment may be nonsurgical or surgical, depending on the patient’s desired lifestyle and the severity of the injury.
The patient should consider their current level of physical activity as well as their plans for future physical activity when deciding on a treatment option. If a patient’s goal is to continue an active lifestyle, surgery may be the treatment of choice because a torn ACL does not heal itself. The alternative treatment option is nonsurgical therapy which consists of protective bracing along with physical therapy involving progressive return to range of motion and muscle-strengthening exercises. The goal is to create natural stability for the knee by developing and strengthening the quadriceps and hamstring muscles.
Cite this ACL Injury – Knee Joint
ACL Injury – Knee Joint. (2017, Apr 02). Retrieved from https://graduateway.com/acl-injury-knee-joint/