The knee joint is one of the most complex joints in the human body and is prone to injury due to the high forces and activities. Many people have experienced knee pain, and many young people who love sports, as well as middle-aged and elderly people, have discomfort such as pain in the front of the knee, pain when going up and down stairs, and difficulty getting up after sitting. The doctor will tell him/her that he/she has chondromalacia patellae after visiting the hospital.
Chondromalacia patellae
patellae (CP), also known as chondromalacia patellae, is a condition in which the cartilage on the back of the patella becomes softened and damaged. Simply put, “softening” means that the texture becomes soft and cannot withstand the pressure it should; “damage” may mean that the surface is worn or even depressed. As you can imagine, how can such an uneven surface ensure the demands of our extensive knee activities? To understand patellar tenderness, we must first understand the structure and function of the patella (kneecap). The patella is the largest seed bone in the body and is located in front of the knee joint, in front of the lower end of the femur, embedded in the quadriceps tendon, and is a triangular flat bone. It is a triangular flat bone with the bottom facing up and the tip down, with a rough front and a smooth articular surface behind, articulating with the patellar surface of the femur.
The patella has the function of protecting the knee joint, avoiding the friction of the quadriceps tendon on the cartilage surface of the femoral condyle, transmitting the force of the quadriceps muscle, and participating in the function of the knee extension device; it has the function of maintaining the stability of the knee joint in the semi-squatting position.
I. Pathological grading of chondromalacia patellae
Arthroscopic chondromalacia of the patella is classified into 5 grades.
1, normal articular cartilage
2, articular cartilage loses its pearl-like appearance and becomes darker, with local softening, swollen areas or ciliated areas <0.5 cm in diameter.
3.Brush-like or ciliated changes within the softened area of articular cartilage, up to 1~2mm deep and ≤1.3cm in diameter.
4.Brush-like or ciliated changes of cartilage reached more than half of the thickness of articular cartilage, with a diameter >1.3cm, and the surface of articular cartilage resembled crab-like changes, with multiple cartilage fragments attached to the cartilage underneath the surface.
Grade IV: The whole layer of articular cartilage is invaded, and the subchondral bone is exposed, showing progressive patellofemoral arthritis.
Second, the clinical manifestations of chondromalacia patellae
1, the common symptoms of the disease at the onset of the knee vague pain or soreness, followed by increased pain, up and down stairs or after exertion symptoms increased, squatting and standing up and other movements difficult to complete;
2. Walking or walking up and down stairs with weak legs;
3.Knee joint activity with subpatellar friction sound;
4.Mild atrophy of the quadriceps muscle;
5, when the temperature changes, the patient’s knee will also generally have significant discomfort.
Three, the causes of chondromalacia patella
1, age.
With the increase of age, the aging of human joint organs caused by the medical term “degenerative changes”.
2, lifestyle habits.
Wearing high heels and walking long distances or standing for long periods of time can put our knee joints in an abnormal state of stress for long periods of time, unknowingly causing chronic damage. Current research shows that the incidence of knee pain in women is significantly higher than in men, and there has been a trend towards a younger age.
Daily exercise, such as tai chi, climbing, and going up and down too many stairs, overstresses the patella and causes strain. Research shows that: when walking on flat ground, when the knee joint is flexed at 9°, the patellofemoral joint force is 0.5 times of body weight; when the knee joint is flexed at 60° up and down stairs, the patellofemoral joint force is 3.3 times of body weight; when the knee joint is flexed at 130°, the force is 7.8 times of body weight.
3, congenital factors: lower limb force line abnormalities or other developmental abnormalities
: such as abnormal femoral condyle development, high patella, low patella, patellar tilt, patellar morphology abnormalities, patellar subluxation or dislocation, etc.
4, occupational factors: athletes, long-distance bus drivers, occupations requiring squatting work, etc., can also cause excessive stress on the patella, causing strain injury. Studies have shown that when a person bounces down from a high place, the pressure on the knee pivot point is 25 times the body weight, and up to 10 times the body weight when jumping quickly, so the high pressure situation will accelerate the wear and tear of the cartilage at the pivot point.
5, environmental factors: autumn and winter young ladies are generally advocate “elegant”, wearing relatively few clothes, especially the legs and knee parts. This makes the knee area by the cold moisture attack, causing knee pain.
6, other factors: trauma or excessive activity, causing intra-patellar venous blockage, resulting in intra-bony high pressure. There are also autoimmune and so on.