Weakness of the knee joint

Introduction In the case of a strong anterior cruciate ligament, some patients felt a tear in the knee joint, and the knee joint was weak and weak. The stability of the knee depends on four ligaments to maintain the two medial lateral ligaments and two cruciate ligaments. The medial and lateral ligaments are located inside and outside the knee joint; the cruciate ligament is inside the knee joint, which is called the anterior cruciate ligament and the posterior cruciate ligament. The anterior cruciate ligament originates from the medial aspect of the lateral femoral condyle, and terminates in the medial intercondylar spine of the tibial plateau forward and downward; the posterior cruciate ligament originates from the lateral medial malleolus of the tibial plateau. Because these two ligaments appear in an intersecting state when they pass through the knee joint, they are called cruciate ligaments.

Cause

1, the cause

The anterior cruciate ligament injury can occur when the knee joint is overstretched or strongly abducted.

2, the pathogenesis

ACL fractures are mostly the result of strong knee extension or strong abduction injury. In the case of strong over-extension under non-loading, ACL injury can also occur in knee joints with ACL injury. The ACL is higher in the body lesion than in the femoral condyle attachment point and in the tibia attachment point. The tibia attachment point injury sometimes appears as avulsion fracture. Kennedy (1974) counts 50 cases with the most common ligament injury (36 cases). %), but only 9 cases (18%) of femoral condyle attachment injury, 2 cases of tibia attachment point injury (4%) unknown 3 cases (6%), more than 30 cases of arthroscopic repair and reconstruction of old ACL injury in the past two years Except for one case of avulsion fracture of the humerus, the ligament was broken.

Dr. DP and his colleagues at the University of Texas Medical School in Houston, USA, selected 1,375 consecutive patients to determine whether the patient's gender, age at injury, or activity at the time of injury was associated with the risk of additional joint damage following anterior cruciate ligament (ACL) injury. Research. In this retrospective case series, researchers used survival analysis to analyze the impact of each factor and statistically compared the effects of time after reconstruction with ACL injury. The results showed that the risk of meniscus injury was significantly higher in male subjects (odds ratio [OR] = 1.5, P < 0.001). If ACL reconstruction was performed more than 6 months after injury, the risk of meniscus injury in male subjects increased 1.5-fold (P=0.021), while female subjects increased 3.4-fold (P<0.001). Patients who underwent ACL reconstruction more than 6 months after injury had a significantly higher risk of meniscal injury than those who underwent ACL reconstruction within 2 weeks after injury (OR=2.2, P<0.001). Joints were developed in patients who underwent ACL reconstruction more than 1 year after injury compared with patients who underwent ACL reconstruction within 2 weeks after injury.

The risk of cartilage damage was significantly higher (OR = 2.1, P < 0.001). The researchers concluded that the incidence of meniscus injury in men is always higher than in women. Over time, the rate of increase in meniscus injury in women is higher. Patients who underwent ACL reconstruction more than 6 months after injury had an increased risk of meniscus injury. Patients who underwent ACL reconstruction more than 1 year after injury had an increased risk of articular cartilage injury.

an examination

Related inspection

Cerebrospinal fluid immunoglobulin synovial fluid routine examination of synovial fluid visual inspection

In the case of strong trauma, some patients feel the tearing of the knee joint, then the knee joint is weak, the joint pain is severe, the swelling is rapid, the blood in the joint, and the subcutaneous ecchymosis around the joint often indicates that the joint capsule damages the joint dysfunction. Patients with old-fashioned injuries may have quadriceps atrophy, a softway or a sense of movement, and decreased exercise capacity. In the examination, the front drawer test (ADT) positive Lachman test was positive, and the axial shift test was positive.

Disease diagnosis

Traumatic history and obvious knee signs combined with X-ray MRI are generally difficult to diagnose. A small number of patients have acute pain, quadriceps protective tendon, and the front drawer test is negative. Further examination under anesthesia is required. See the posterior cruciate ligament. damage.

Knee arthroscopy examination of cleaned blood, visible ACL fracture end bleeding or small blood clots. Subserosal ligament injury appears normal under arthroscopy, but its length and tension may indicate the possibility of this injury. X-ray examination of the knee can show the humeral condyle fracture, and the internal and external stress can be seen when the joint space is widened.

Auxiliary inspection

1, Lachman test patients lying flat knees 15-20 °, feet placed on the bed. The examiner grasps the lower end of the patient's femur with one hand and grasps the upper end of the humerus with one hand to push forward and backward in opposite directions. If there is more than the positive side of the forward movement, it should be considered positive but must pay attention to the difference. Whether it is pulled back from the post-sink position to the normal position or is indeed forward. This test originally intended to detect the forward movement to clear the ACL, especially to judge the ACL. The front inner bundle or the rear outer bundle is damaged.

2, X-ray examination of the knee can show the humeral intercondylar torsion fracture, when the internal and external vertebral stress examination, it can be seen that the joint space of one side is widened. Occasionally, Segond fractures can be seen.

3, MRI acute MRI examination diagnosis rate of up to 5% or more in the chronic phase due to clear signs, MRI is not necessary.

Differential diagnosis

It is different from the knee joint. The inability to fully extend the knee joint is a clinical manifestation of knee collateral ligament injury. The joint capsule of the knee joint is weak, and the stability of the joint mainly depends on the ligament and muscle. The medial collateral ligament is the most important, followed by the lateral collateral ligament and the anterior and posterior cruciate ligaments.

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