In the United States, more than 9 million patients sought medical care for knee disorders in 2001. The knee joint is the most complex joint in the body and is critical to movement. Good extension and flexion stability is an important foundation for knee function. Two complete sets of ligaments, the cruciate ligament and the collateral ligament, ensure the stability of the knee joint.
Cruciate ligament
The cruciate ligament is located inside the knee joint and connects the femur to the tibia. It consists of many bundles of fibers that hold the joint together like a rope during knee flexion and extension. This stability is necessary for normal knee movement. The name of the cruciate ligament indicates that the ligaments are arranged in a cross pattern and are essential to function within the knee joint. Not only are the cruciate ligaments located inside the knee joint, but they are arranged in an “X” shape. The anterior ligament is called the anterior cruciate ligament and the posterior ligament is called the posterior cruciate ligament.
Anterior Cruciate Ligament Injuries
The anterior cruciate ligament prevents the tibia from moving anteriorly to the femur and is often damaged in the following ways.
1.Sudden change in direction of motion
2, deceleration during running
3, jumping from a height and landing on the knee joint
4, contact injury, such as playing soccer sprain
Awareness of ACL injuries
When the ACL is injured, you may hear a popping sound and feel a loss of control of the knee joint, but pain may not occur immediately. Two to 12 hours after the injury, the knee becomes swollen and painful when standing. At this point, ice should be applied to relieve swelling and elevate the affected knee before seeking medical attention. Continuing to walk or run after an ACL injury can severely damage the cushioning cartilage in the knee joint, and cartilage damage can lead to a complete loss of knee function and may require consideration of an artificial knee in the future. Therefore, we should pay great attention to the diagnosis and treatment of ACL injury, not because we can still walk, or even run and jump after knee injury and miss the best time for treatment.
Diagnosis of ACL injury
The diagnosis of ACL injury is based on a detailed physical examination. The physical examination, such as Lachman’s sign and axial shift test, can be used to understand the stability of the ACL, and even the results of the physical examination are directly related to the choice of treatment. X-rays of the knee joint, MRI or in some cases knee arthroscopy will also be performed.
Treatment of ACL injuries
Depending on the nature of the ACL injury surgical or non-surgical treatment can be used.
Non-surgical treatment.
Older adults or those with low exercise requirements, those who still have good knee stability, those who have performed strength restoration exercises, and those who regularly use crutches to maintain joint stability.
Surgical treatment (including incisional and arthroscopic surgery)
Usually, autologous or allogeneic patellar ligament or N cord tendon is used to reconstruct the ACL by crossing the starting and ending points of the femur and tibia, or artificial ligaments can be used to reconstruct the ACL, and postoperative muscle strength restoration exercises are performed to maintain the flexibility of the joint.
Posterior cruciate ligament injury
The incidence of posterior cruciate ligament (posterior cruciate ligament) injuries is lower than that of the anterior cruciate ligament. They usually occur with anterior knee impingement or sprains. In a posterior cruciate ligament injury, the tibia shifts backward, causing a breakdown in knee stability. Direct friction between the femur and the end of the tibia wears away the smooth, thin articular cartilage, leading to knee osteoarthritis.
Treatment of posterior cruciate ligament injury
Because some patients have no symptoms of knee instability after a posterior cruciate ligament injury, it often goes unnoticed. The reconstruction of the posterior cruciate ligament under knee arthroscopy is technically demanding and complex, and objectively some patients are not treated properly. Therefore, there is still controversy on how to treat posterior cruciate ligament injury. We believe that some patients can be treated with exercise after posterior cruciate ligament injury, but such treatment is not ideal because of the sacrifice of osteophytes and premature aging of the knee joint. Our opinion is that most of the patients with posterior cruciate ligament injuries or combined with other ligament injuries that seriously endanger the stability of the knee joint should actively use autologous N-cord tendon to reconstruct the posterior cruciate ligament, restore the stability of the knee joint, and make a good recovery of the knee function through a detailed rehabilitation program.
Lateral collateral ligament
The lateral collateral ligaments are located on the medial and lateral sides of the knee. The medial collateral ligament (MCL) connects the femur to the tibia and provides stability to the medial side of the joint. The lateral collateral ligament (LCL) connects the femur to the fibula and provides stability to the lateral aspect of the joint.
Medial collateral ligament injuries are usually caused by violence to the lateral aspect of the knee and are associated with severe pain on the medial aspect of the joint. Injuries to the lateral collateral ligament are relatively rare.
Lateral collateral ligament injuries
Because the medial collateral ligament is primarily a membranous structure, it has a tendency to heal easily. When the medial collateral ligament is injured, most conservative treatment is effective.
Using the R.I.C.E rule.
Rest, ice, compression dressing, elevation of the affected limb: rest to give the knee adequate time to heal; ice two to three times a day for 15 to 20 minutes; compression dressing to limit swelling and use an elastic bandage and crutches; elevate the affected limb as much as possible. Rehabilitation program under the protection of a knee brace with locking. Surgery is required when the medial collateral ligament is completely ruptured or when the injury is not self-healing. With satisfactory surgical reconstruction, knee stability can be restored and many patients can regain their pre-injury level of motion. The lateral collateral ligament, because it is primarily a tendinous structure, does not heal easily after injury and often requires reconstruction after trauma with lateral instability. Neglecting the treatment of the lateral structures, especially when combined with other ligament injuries, will result in eventual failure of the surgery.