knee meniscus injury
Introduction
Brief introduction of knee meniscus injury Knee meniscus injury is a common condition of the knee joint. The meniscus is located on the tibial articular surface and has medial and lateral half-moon shaped bone. The medial meniscus has a "C" shape. The anterior horn is attached to the anterior cruciate ligament attachment point. The posterior horn is attached to the intercondylar humerus and the posterior cruciate ligament attachment point. The middle edge of the rim is closely connected to the medial collateral ligament. The plate has an "O" shape, the anterior horn is attached to the anterior cruciate ligament attachment point, and the posterior horn is attached to the posterior horn of the medial meniscus. The outer edge is not connected to the lateral collateral ligament, and its activity is larger than that of the medial meniscus. basic knowledge The proportion of illness: 0.001% Susceptible people: no specific population Mode of infection: non-infectious Complications: knee injury
Cause
Causes of knee meniscus injury
Trauma (90%)
The disease is a traumatic disease, mostly caused by torsion external force. When one leg is loaded, the calf is fixed in the semi-flexion, the body and the thigh are suddenly internal rotation, and the medial meniscus is between the femoral condyle and the tibia. The meniscus tears, such as the knee flexion when the sprain is greater, the more the torn part, the mechanism of the lateral meniscus injury is the same, but the direction of the force is opposite, the ruptured meniscus, such as part of the slip into the joint In the meantime, the joint activity is mechanically impeded, hindering the joint's flexion and extension, and forming an "interlocking". In severe trauma cases, the meniscus, cruciate ligament and collateral ligament can be damaged at the same time. The part of the meniscus can occur in the anterior, posterior, middle or marginal part of the meniscus. The shape of the injury can be transverse. Cracked, horizontally split or irregular, even broken into free parts of the joint.
Pathogenesis
Meniscus injury is most likely to occur when the knee joint is flexed to straight and accompanied by rotation. The meniscus injury is mostly in the medial meniscus. The most common one is the injury of the posterior horn of the meniscus, and the longitudinal fracture is the most. The length, depth and location of the tear depends on the relationship between the femur and the humerus at the posterior horn of the meniscus. Congenital anomalies in the meniscus, especially the lateral discoid cartilage, are more likely to cause degeneration or damage. Congenital joint relaxation and other internal disorders can also increase the risk of meniscus injury.
Prevention
Knee meniscus injury prevention
In order to promote recovery, before and after meniscal surgery, the quadriceps function should be exercised hard. The patient is lying on the bed, straightening the lower limbs, lifting the knee bone (tibia) upwards, then relaxing, repeatedly exerting force, or stretching the lower limbs. Straight up, put down, repeat, to a certain extent, you can also practice a certain weight of sandbags on your ankle. After exercising, the quadriceps are strong and powerful, which is good for maintaining joint stability. Exercise should be performed before surgery. At the beginning, the day after the operation continues, the wound is still painful, and the patient often has concerns, such as fear of cracking of the wound, bleeding inside, etc., must eliminate the worry, exercise painfully, load the weight two weeks after the operation, gradually increase The range of joint activity, exercise level and recovery effect have obvious relationship, the better the exercise, the better the effect.
Complication
Complications of knee meniscus injury Complications knee injury
When the knee joint meniscus is damaged, it mainly causes joint pain and dysfunction. In severe cases, knee joint interlocking symptoms may occur. The so-called knee joint interlocking means that the knee joint is restricted in flexion and extension when it is in a certain position. There is obvious pain, so patients with this disease should be actively treated to prevent complications.
Symptom
Knee Meniscus Injury Symptoms Common Symptoms Traumatic Joint Swelling Knee Joint Clearance and Pain Knees Sickness and Pain Cyst Muscle Atrophy
Common clinical manifestations after meniscal injury include localized pain, joint swelling, squeaking and interlocking, quadriceps atrophy, soft legs, and clear tenderness in the knee joint or meniscus.
1. tenderness: Common signs are localized tenderness around the medial and lateral space of the knee joint or around the meniscus.
2. McMurray test: the patient is in supine position, the examiner uses one hand to resist the inner edge of the joint, controls the medial meniscus, the other hand holds the foot, the knee joint is fully flexed, the calf is rotated inward, and then the knee joint is slowly extended. To feel or feel the bounce or bounce; then hold the outer edge of the joint by hand, control the lateral meniscus, the inner leg of the calf valgus, slowly stretch the knee joint, hear or feel the sound or bounce, that is, the test is positive.
The sound generated by the McMurray test or the sudden pain of the patient during the examination often has a certain significance for the positioning of the meniscus tear: the knee joint is fully flexed to 90°, and the posterior margin of the meniscus is often prompted; When the knee joint is struck in a large straight position, it prompts the middle or front of the meniscus to tear.
3.Apley grinding test: the patient is in a prone position, knees 90°, the front of the thigh is fixed on the examination table, the foot and the calf are lifted up, the joint is separated and rotated, and the tension is tightened on the ligament, if the ligament is torn There was significant pain during the test. Thereafter, the knee joint is in the same position, the foot and the lower leg are pressed down and the joint is rotated, and the joint is slowly flexed and stretched. When the meniscus is torn, the knee joint space can have obvious bounce and pain.
4. Classification of meniscus injury: The classification of meniscus tears has guiding significance for diagnosis and selection of reasonable surgical treatment methods.
There are many different classification methods for meniscal tears. It is more common to divide them into marginal, central, longitudinal ruptures (ie, "barrel-type" ruptures), anterior or posterior valvular ruptures, and rare half-months. The horizontal shape of the middle of the plate is broken.
Examine
Examination of knee joint meniscus injury
There are many inspection methods for this disease, which are as follows:
1. The tenderness site: the site of tenderness is generally the site of the lesion, which is important for the diagnosis of meniscus injury and the determination of the site of injury. The knee is placed in the semi-flexion position during the examination, in the medial and lateral space of the knee joint, along the The upper edge of the humerus (ie, the edge of the meniscus) is pressed with the thumb from the back to the point. There is a fixed tenderness at the meniscus injury. For example, while pressing, the knee is flexibly stretched or the calf is rotated inside and outside. The pain is more painful. Significant, sometimes touching the meniscus of abnormal activity.
2. McMurray test (spin test): The patient is supine, the examiner holds the calf chin in one hand, the knee is supported by the other hand, the hip and knee are flexed as much as possible, and then the calf is abducted, externally rotated and abducted , internal rotation, or adduction, internal rotation, or adduction, external rotation, gradually straightening, the occurrence of pain or noise is positive, according to the pain and the sound of the site to determine the location of the injury.
3. Strong over-extension or over-flexion test: Passive over-extension or over-flexion of the knee joint, such as the frontal injury of the meniscus, over-extension can cause pain; such as posterior injury of the meniscus, over-flexion can cause pain.
4. Lateral pressure test: knee extension, strong passive adduction or abduction of the knee, if there is meniscus injury, the joint joint space is caused by compression caused by pain.
5. One-leg squat test: Use a single-leg weight to gradually squat from the standing position, and then stand from the lower squat position, the healthy side is normal, the affected side is squatting or standing at a certain position, due to the damaged meniscus squeezed Pressure can cause pain in the joint space, and can't even squat or stand up.
6. Gravity test: the patient takes the lateral position, lifts the lower limb for the active flexion and extension of the knee joint, and when the joint joint space is down, the pain caused by the meniscus of the injury is caused; otherwise, when the joint joint space is upward, There is no pain.
7. Grinding test: The patient takes the prone position and the knee joint is flexed. The examiner holds the crotch with both hands and presses the lower leg while performing internal and external rotation activities. The damaged meniscus is caused by the squeeze and grinding; otherwise, the lower leg If you raise the internal and external rotation activities, there will be no pain.
8. X-ray examination: taking the X-ray positive lateral radiograph, although it can not show the meniscus injury, but can exclude other bone and joint diseases, knee joint angiography is of little significance for diagnosis, and can increase the patient's pain, should not be used.
9. Knee arthroscopy: Arthroscopy can directly observe the location, type and other structures of the meniscus injury, which is helpful for the diagnosis of difficult cases.
Diagnosis
Diagnosis and diagnosis of knee joint meniscus injury
diagnosis
The diagnosis of meniscus injury is mainly based on medical history and clinical examination. Most patients have a history of trauma, and there are fixed pain and pressure energy in the joint space of the affected side. Combined with various examinations, most of them can make a correct diagnosis. For patients with severe trauma, Attention should be paid to the presence or absence of combined collateral ligament and cruciate ligament injury. For advanced cases, attention should be paid to the presence of secondary traumatic arthritis.
The diagnosis of this disease can be summarized as the following points:
1. History of injury: Most patients have a more accurate history of trauma.
2, pain: meniscus injury combined with synovial injury, so the pain is heavier, especially on the injured side.
3, joint swelling: caused by blood, effusion.
4, the sound: the joint side of the wound can have a crisp sound.
5, joint lock: that is, the joint is suddenly stuck during the activity, which is caused by the broken meniscus stuck between the femoral condyle and the tibial plateau.
6, quadriceps atrophy: generally appear in chronic medical records.
The diagnosis of this disease should be differentiated from other knee diseases, such as intra-articular tumors, patella softening, etc. Under modern medical conditions, X-ray films, CT films and arthroscopy can be used to confirm the diagnosis. X-ray films can exclude other knee diseases. , joint inflation imaging, CT can determine the location of meniscus injury.
In addition, the disease needs to be differentiated from meniscus degeneration: the common manifestation of meniscus degeneration or tear is the abnormal signal in the meniscus. The identification of the two is to determine whether the abnormal signal affects the articular surface, and the MR I diagnosis is grade I. Class II signal, can not be found under arthroscopy, because the arthroscopic can not see the inside of the meniscus, only the surface of the meniscus can be seen, while MR I has a clear diagnosis of the meniscus variable performance, and the I and II signals are meniscus degeneration. Generally, conservative treatment is needed, and the grade III signal is a meniscal tear. It requires surgery. The role of MR I in the diagnosis of meniscus definitely provides an accurate imaging basis for orthopedic surgeons. The MR I check is routinely performed.
