What Are the Different Types of Knee Ligament Injury?

The joint capsule of the knee joint is weak and loose. The stability of the joint mainly depends on the ligaments and muscles. The medial collateral ligament is the most important. It is located between the femoral condyle and the tibial condyle. There are two layers of deep and shallow fibers, which are triangular in shape. It is very tough. The deep fibers are fused with the joint capsule, and partly connected with the medial meniscus. The lateral collateral ligament rises from the epicondyle of the femur. The structure is attached to the small head of the fibula together. There is a bursal gap between the lateral collateral ligament and the lateral meniscus. When the knee joint is straightened, the collateral ligaments on both sides are tightened without adduction, abduction and rotation. When the knee flexes, the ligaments gradually relax, and the adduction, abduction and rotation of the knee joint also increase. ^[1-2]

Lin Anru	(Chief physician)	Department of Traumatology and Orthopedics, Nanfang Hospital, Southern Medical University
Guo Gang	(Deputy Chief Physician)	Department of Traumatology and Orthopedics, Nanfang Hospital, Southern Medical University

There are anterior and posterior cruciate ligaments (also known as cruciate ligaments) in the knee joint. The anterior cruciate ligament starts from the front of the tibial intercondylar bulge, and stops rearward, upper, and outer at the medial and lower sides of the femoral condyle. The posterior cruciate ligament starts from the tibial condyle. The anteroposterior, forward, upper, and inner ends of the lateral side of the femoral medial malleolus, whether the knee joint is straight or flexed, the anterior cruciate ligament is tense, the anterior cruciate ligament can prevent the tibia from moving forward, and the posterior cruciate ligament can prevent The tibia moves backwards. In general, knee ligament injuries have a history of trauma, mostly in adolescents. Correct diagnosis and treatment can generally achieve good recovery results.

Western Medicine Name

Knee ligament injury

Other name

Anterior cruciate ligament injury

Affiliated Department

Surgery-Orthopedics

Disease site

Knee ligament

The main symptoms

Severe pain

Main cause

trauma

Multiple groups

teens

Contagious

Non-contagious

Overview of knee ligament injuries

The joint capsule of the knee joint is weak and loose. The stability of the joint mainly depends on the ligaments and muscles. The medial collateral ligament is the most important. It is located between the femoral condyle and the tibial condyle. There are two layers of deep and shallow fibers, which are triangular in shape. It is very tough. The deep fibers are fused with the joint capsule, and partly connected with the medial meniscus. The lateral collateral ligament rises from the epicondyle of the femur. Its distal end has a tendon structure, and it will synthesize with the biceps tendon to form a combined tendon. The structure is attached to the small head of the fibula together. There is a bursal gap between the lateral collateral ligament and the lateral meniscus. When the knee joint is straightened, the collateral ligaments on both sides are tightened without adduction, abduction and rotation. When the knee flexes, the ligaments gradually relax, and the adduction, abduction and rotation of the knee joint also increase. ^[1-2]

Symptoms and signs of knee ligament injury

Have a history of trauma. It is more common in adolescents, more in men than women, and in athletes most often, the sound of a ligament rupture can sometimes be heard when injured, and soon it can no longer continue to exercise due to severe pain or swelling, tenderness and effusion at the knee joint ( Blood), knee muscle spasm, the patient is afraid to move the knee, the knee joint is in a forced position, or straight, or flexion of the knee joint collateral ligament breaks have obvious tender points. Falling from a height, direct violence such as a car accident can also directly lead to ligament damage or other injuries accompanied by fractures. Ligament injury is often associated with knee meniscus injury, and MRI can help diagnose.

Knee joint ligament injury pathophysiology

1. Medial collateral ligament injury is caused by valgus knee valgus. When the knee joint is violently turned outward on the outside of the knee joint, the medial collateral ligament will be torn. When the knee joint is semi-flexed, abduction and rotation of the lower leg will also break the medial collateral ligament. Sports trauma can be combined with meniscus and anterior cruciate ligament injuries such as football, skiing, wrestling and other competitive events.

2. The lateral collateral ligament injury is mainly caused by varus knee varus. Because the lateral zygomatic tibia bundle is relatively strong, the lateral collateral ligament injury alone is rare, and it is easy to combine meniscus and posterior cruciate ligament damage. If the violence is strong, the iliotibial bundle and peroneal The common nerve is unavoidable.

3. Anterior cruciate ligament injury The knee canal rupture can be ruptured either in the varus or varus injury in the flexed position. Generally, the anterior cruciate ligament is rarely damaged alone. It is often combined with medial, lateral ligament and meniscus injuries. When the knee joint is overextended, the anterior cruciate ligament may be respected alone. In addition, the violence comes from behind the knee joint, the tibia The upper force can also break the anterior cruciate ligament, and anterior cruciate ligament injury is also more common in competitive sports.

4. Posterior cruciate ligament injury Whether the knee joint is in flexion or extension, the violence from the front that moves the upper end of the tibia backward can break the posterior cruciate ligament. More common in direct violent trauma. Patients with dislocation of the knee can be injured simultaneously with the anterior cruciate ligament.

Ligament damage can be divided into sprains (ie, partial fiber breaks), partial ligament breaks, complete breaks, and joint injuries. For example, anterior cruciate ligament breaks can be combined with medial collateral ligaments and medial meniscus injuries, becoming "triple wound" The part can be divided into a ligament body rupture, a rupture at the junction of the ligament and bone, and an avulsion fracture at the ligament attachment. The first type of wound heals slowly and has poor strength, and the third type is the strongest after healing. ^[3-4]

Examination and diagnosis of knee ligament injury

1. Lateral stress test It is very painful to do lateral stress test in the acute phase. You can wait for several days or perform the operation after local anesthesia at the pain point, and perform passive varus and valgus knee movements with the knee fully extended and flexed at 20-30 degrees, and compare it with the contralateral side, if there is pain Or when the varus and valgus angle is found to be outside the normal range and there is a sense of bouncing, it is suggested that the collateral ligament is sprained or broken.

2. Drawer test: The knee joint is flexed 90 degrees, and the lower leg is hanging down. The examiner holds the upper tibial segment with both hands for anterior and posterior movements. After the normal position of the tibial tubercle is restored, pay attention to the extent of the tibial tubercle movement. Rupture of the cruciate ligament. An increase in retrograde movement indicates a rupture of the posterior cruciate ligament. Since the normal tibia can also have mild passive anteroposterior motion at 90 degrees of normal knee flexion, it is necessary to compare the healthy side with the affected side. When the anterior cruciate ligament is broken, the tibial advancement is only slightly larger than normal. If the advancement is significantly increased, it may indicate that there is also a medial collateral ligament injury. Drawer tests in the acute phase are painful. It should be performed after anesthesia.

3. Axial shift test This test is used to adhere to the knee joint instability after anterior cruciate ligament tons. The patient was lying on his side with the examiner standing on one side, holding his ankle and flexing his knee to 90 degrees. Apply force to the outside of the knee with the other hand to make the knee in the valgus position, then slowly straighten the knee joint until the 30-degree flexion feels pain and bouncing, which is a positive result. This is mainly in the knee flexion position, the lateral tibial plateau is dislocated forward, the femoral condyle slides to the rear of the tibial plateau, and the femoral condyle suddenly resets during the straightening process, causing pain.

Radiographic and arthroscopy plain radiographs can only show avulsed fractures. To show whether there is damage to the medial and lateral collateral ligaments, a stress radiograph can be taken. That is, the film is taken in the knee varus and knee reversal positions. This position is very painful and needs to be performed after local anesthesia. The opening of the inner and outer gaps is compared on the X-ray film. It is generally considered that the gap between the two sides is within 4mm Mild sprain, partial fracture of 4-12mm, complete fracture above 12mm, may also be accompanied by anterior cruciate ligament injury.

MRI can be clear. The condition of the anterior and posterior cruciate ligaments is shown, and hidden fracture lines can also be found.

Arthroscopy is important for the diagnosis of cruciate ligament damage. Anterior cruciate ligament damage can be found in 75% of acute traumatic joint hematomas. Two thirds of the cases are accompanied by medial meniscus tears, and one fifth are articular cartilage defects. Arthroscopy has provided a new understanding for the diagnosis and treatment of knee ligament injuries.

Treatment of knee ligament injury

The main method of knee ligament injury treatment is arthroscopy: obtain a clear diagnosis after arthroscopy, and then develop a treatment plan: meniscus suture or shaping, cruciate ligament reconstruction or plasma thermotherapy, repair or reconstruction of lateral collateral ligament, avulsion fracture Reset fixed, etc.

1. Medial collateral ligament injury Medial collateral ligament sprain or partial rupture (deep layer) can be treated conservatively, and fixed with long leg cast for 4-6 weeks. Those with complete rupture should be repaired as early as possible, if there is meniscus injury and anterior cruciate ligament injury Patients should also be treated under arthroscope at the same time.

2, lateral collateral ligament injury lateral collateral ligament rupture should be immediately repaired. Late lateral collateral ligament injury requires reconstructive surgery.

3. Anterior cruciate ligament injury is currently the mainstream approach to reconstruction from the anatomy of the hamstring tendon. In addition, dual-beam reconstruction is also possible, and allogeneic materials or artificial tendons can be used as materials. According to the type of injury, patient activity, age, medical expenses and other comprehensive consideration.

4. The posterior cruciate ligament injury is mainly reconstruction, and the issues to be considered are similar to those of the anterior cruciate ligament. The main surgical methods are arthroscopic bone tunneling and arthroscopic assisted bone embedding.

After the ligament surgery is completed, the doctor will provide a thoughtful postoperative rehabilitation plan that varies from person to person. Mainly to restore the quadriceps muscle strength, the range of motion of the knee joint, and reconstruct the proprioception of the ligaments.

Sports enthusiasts or athletes are susceptible to this injury. Proper landing techniques are important to prevent knee injuries. It is recommended that when the athlete lands, the soles of the feet should be on the ground, the knees should be bent, and the trunk should be leaned forward slightly. Try to avoid lateral or forward movements of the knee joint. Remember that the knee joint cannot be twisted inward when landing, and the impact force is minimized.

After knee injury, if you can immediately find the right doctor, make the correct diagnosis, perform the correct operation, and cooperate with the doctor and physical therapist to complete the rehabilitation plan after surgery. The expected surgical effect is very satisfactory, and even professional athletes can return to the competitive state before the injury. ^[5]