Retropatellar pain

Introduction The general symptoms of patellofemoral articular cartilage injury, the most important is post-tarnea pain. In the active or semi-squatting position, the initial stage is acid deficiency and discomfort, and later develops into persistent or progressive soreness. Often the pain is obvious at the beginning of the activity, the activity is relieved, and the pain is aggravated at the end of the activity or at rest. This pain is sometimes very distinctive and is often described as "caries and soreness." It is sore when going up and down the stairs, especially when going downstairs or downhill. There are often complaints about knees being soft and "slightly falling down." Sometimes there are joint interlocking symptoms.

Cause

(1) Causes of the disease

Any mechanism that affects the normal secretion of the synovial membrane or the articular cartilage extrusion mechanism, which hinders the normal movement of the joint, can cause damage to the articular cartilage.

(two) pathogenesis

1. Acute or chronic trauma: It may directly hit the cartilage and destroy the collagen fiber mesh arch structure in the cartilage. It can also directly cause tangential fracture of cartilage. Chrisman has studied the relationship between trauma and tibial rickets in a biochemical perspective for many years. He found that within 2 hours after cartilage injury, the concentration of free arachidonic acid in cartilage can be increased by 4 times. Arachidonic acid is the main component of the phospholipid membrane. The prostaglandin precursor, its product is converted into prostaglandin E2, stimulates the AMP cycle, releases the tissue protein kinase, destroys the chondroitin sulfate-protein-binding chain in the cartilage matrix, and makes the cartilage matrix. Lost, causing cartilage to soften. Metabolites enter the synovial fluid to cause synovial inflammatory reaction, which in turn stimulates the synovial membrane to release a large amount of enzymes, further destroying the cartilage and causing a vicious circle.

2. Strain of the patellofemoral joint: long-term abnormal friction and compression of the tibial cartilage, especially in the knee flexion position, repeated lifting, jumping, weight, and torsion can cause excessive stress between the tibiofemoral Or the uneven distribution of stress causes the tibial cartilage to be easily damaged and suffer from tibial rickets.

3. patellofemoral joint instability: common unstable factors such as high or low tibia, knee Q angle abnormality, humeral tilt, humeral torsion deformity, humerus or femoral condyle dysplasia, due to abnormal position of the humerus or abnormal line alignment, or The contact surface between the patellofemoral and the abnormal contact stress cause the tibial rickets. Many scholars have done a lot of work on the stress distribution and stress test of the patellofemoral joints. There are high contact pressure theory, low contact pressure theory, pressure division unevenness theory and sacral bone internal pressure increase theory, etc., all have experimental support. However, whether the pressure is too high, the pressure is insufficient, or the pressure is not uniform, as long as the pressure exceeds or does not reach the normal range of the tibial cartilage, it may cause cartilage degeneration.

4. Pathological changes: The main pathological changes of tibial cartilage are manifested as softening, yellowing, cracking, exfoliation, ulcer formation of the tibial cartilage, as well as synovial inflammation, increased secretion, periorbital fasciitis, parasympathetic support Sexual change and hyperplasia or contracture. The exfoliated cartilage pieces may be detached into the joint mouse in the joint cavity, causing the knee joint to interlock.

an examination

Related inspection

Bone and joint MRI examination of bone and joint soft tissue CT examination

Film degree exam:

(1) X-ray seeing: taking ordinary X-ray film does not make much sense for diagnosis. However, if you choose to take the axial position of the humerus at different knee angles, you can observe the shape of the tibia, the degree of hardening of the subchondral bone, and measure some indexes of the tibia, such as the humerus angle, the tibia depth index, the tibia index, the groove angle, the overlap angle, etc. . Lateral knee radiographs can detect abnormal position of the humerus. Normally, the length of the tibia (P) is equal to the length of the patellofemoral ligament (PT). When the PT exceeds 15% of P or exceeds 1 cm, it is a high tibia.

(2) MRI examination: exfoliation and ulceration of the tibial cartilage can be found.

Differential diagnosis

Differential diagnosis of post-tarnea pain:

1. Tibial pain: In the early stage of the tibia femoral pain syndrome, the knees may experience pain when walking, going up and down the stairs, and standing under the armpits. In severe cases, there may be sudden knees unable to force or even stand unstable during walking.

2, underarm pain: one of the signs of instability of the humerus, tenderness is mostly distributed in the inner edge of the tibia and the medial support zone. When the examiner presses the patient's tibia and performs the flexion and extension test, it can induce subgingival pain. The clinical tenderness is sometimes inconsistent with the painful part of the patient's complaint.

3, knee pain: tibia knee pain syndrome is a professional vocabulary that describes the pain in front of or around the humerus. Patellaofemoral Pain Syndrome, also known as anterior knee pain, is caused by abnormal movement of the femur during flexion.

4, post-knee pain: the main diseased tissue that causes pain in the knee, the knee joint (the fossa) pain accounted for 1 / 5 to 1/4 of the incidence of knee pain, can not be ignored.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.