The knee joint is the most complex joint in the body and is critical to movement. Because of its high activity demands, it has a greater chance of injury than other joints.
Good extension and flexion stability is an important foundation for the function of the knee joint. The intra-articular cruciate ligament and the extra-articular collateral ligament ensure the stability of the knee joint.
I. 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 cross-linked and are essential to function within the knee joint. Not only are the cruciate ligaments located inside the knee joint, but they are crossed and arranged in an “X” shape. The anterior ligament is called the anterior cruciate ligament (ACL) and the posterior ligament is called the posterior cruciate ligament (PCL).
(A) Anterior cruciate ligament injury
The ACL prevents the tibia from moving anteriorly to the femur and is often damaged in the following ways.
1, sudden change of 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
ACL injuries can be heard as a popping sound and a feeling of loss of control of the knee, but pain may not occur immediately. Swelling of the knee occurs 2 to 12 hours after the injury and is painful when standing. Continuing to walk or run after an ACL injury can severely damage the cushioning cartilage in the knee joint, which 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. 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, magnetic resonance imaging (MRI) or, in some cases, arthroscopic exploration of the knee will also be performed.
Treatment of ACL injuries
Treatment can be surgical or non-surgical, depending on the nature of the ACL injury.
Non-surgical treatment.
1.The elderly or those who do not require high sports volume
2.Knee joint stability is still good
3. Those who have done strength restoration exercises and often use crutches to maintain joint stability
Surgical treatment (including incisional surgery and arthroscopic surgery)
1.Usually use autologous or allogeneic patellar ligament or N-tendon to cross the anterior cruciate ligament at the starting and ending points of femur and tibia and reconstruct
2. Artificial ligaments can also be used to reconstruct the anterior cruciate ligament
3.Postoperative muscle strength restoration exercise to maintain joint flexibility
4.According to the situation, most of the cases adopt the double tunneling technique of autologous N cord tendon to restore the ACL function to the maximum, and achieve promising results. At present, about 300 cases are to be completed every year, good results have been achieved, and the reconstruction technology has been in line with the world leading technology.
(II) Posterior cruciate ligament injury
The incidence of posterior cruciate ligament (PCL) injury is lower than that of anterior cruciate ligament. It usually occurs during anterior knee impingement or sprain.
In a PCL injury, the tibia is displaced posteriorly, causing a breakdown in knee stability. Direct friction between the femur and tibial ends 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. Moreover, the reconstruction of the posterior cruciate ligament under knee arthroscopy is technically demanding and complex, and objectively some patients are not properly treated. Therefore, there is still a controversy on how to treat PCL after injury. We believe that some patients can be treated after PCL injury through exercise, but this 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 PCL injury 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 PCL, restore the stability of the knee joint, and make a good recovery of the knee function through a detailed rehabilitation program.
II. Lateral collateral ligament
The lateral collateral ligament is located on the medial and lateral side of the knee joint. The medial collateral ligament (MCL) connects the femur and 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 the ability 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 bandages, and 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 bandages to limit swelling, and elastic bandages and crutches; and elevation of the affected limb if possible. Do a 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.