Chondromalacia patellae is the common name for it. Its actual name is chondromalacia patellae, or chondromalacia patellae.
This disease, or injury, of the locomotor system is a common and prevalent condition among athletes and middle-aged and elderly people. It is a degenerative degeneration of the articular surface of the patellofemoral cartilage caused by long-term chronic wear and tear of the patellofemoral joint cartilage, resulting in softening, cracking, peeling and other lesions of the articular cartilage. Ge Jie, Center for Rehabilitation Medicine, Peking University Third Hospital
The mechanism of injury is mainly strain, but there are also a few people who started gradually after a certain trauma, that is, the development of osteoarthrosis after an acute injury to the patellar cartilage. The mechanism of strain is usually due to the knee joint being in a semi-squatting position for a long time, or repeated flexion and extension and twisting, which causes excessive misalignment, impact and twisting friction between the corresponding articular surfaces of the patella and femur.
This happens with many of the movements we make in our daily lives. For example, going up and down stairs is repeated flexion and extension of the knee joint, and the patella will have frictional twisting action. To give a value that no one would expect, the force of the patella in the knee flexion position when going up the stairs is 3.3-4 times the body weight! In other words, if the weight is 100 pounds (which is already very light!) In other words, if the weight is 100 pounds (which is very light!), the force on the patella at the moment of going up the steps is 330 pounds! That’s why we don’t recommend climbing as a form of daily exercise for the elderly! Climbing too many steps is a great torture and destruction to the cartilage of the knee joint!
There are many signs and symptoms of chondromalacia patellae. The first is pain in the knee joint, as the degree of cartilage damage varies, so does the degree of pain. In lighter cases, only going up and down stairs will hurt, and maybe the knee joint will suddenly hit soft and weak. Sometimes it hurts when you are in a semi-squatting position, such as during the process of moving from squatting to standing, especially when you are carrying heavy objects. In severe cases, it hurts during activities of daily living, and there is knee weakness when walking.
Secondly, when the knee joint flexes and extends, there is often a rattling sound under the patella, and in severe cases, when you put your hand on the patella, you can feel a “rustling” sound, like sand being spread in the bearing.
In addition, the quadriceps muscle atrophies. This is the atrophy of the muscles on the front side of the thigh. When the symptoms are similar in both legs, it may not be obvious because both legs have atrophy. If the symptoms are more severe in one leg, you will see that the leg is significantly thinner and the muscles are significantly weaker.
It also causes pain when pressing on the patella with the hand and pain during squatting. The knee joint may also be swollen with joint effusion. If it has been painful for a long time, after taking an X-ray, it may be found that the patellofemoral joint surface is hardened, the bone shows cystic degeneration and decalcification, and there will be osteophytes around the patella.
If you have these conditions, you should be alert to whether you have developed chondromalacia patellae. It is best to go to the hospital for a checkup to diagnose whether it is “chondromalacia patella” or some other problem. If it is diagnosed as chondromalacia patella, it should be treated as soon as possible to avoid the deterioration of the condition.
The diagram above shows the mechanism of chondromalacia patella and the degree of damage.
The top left diagram shows that when the knee joint is straight and relaxed, the patella is also “relaxed” and there is no pressure or friction. The lower left diagram is a diagram of the forces applied during knee flexion and extension. The force of the quadriceps and the load of resistance in the direction of the lower leg will have a component force to compress the patella against the femur, and at the same time rub with the knee flexion and extension. Therefore, more such movements will cause strain on the patellar cartilage, and such movements should be avoided with patellar tenderness.
The diagrams on the right show the grading of patellar tenderness. I, II, III and IV degrees are clear at a glance.
(The appearance of chondromalacia patella on x-ray)
For the treatment of chondromalacia patella, non-surgical rehabilitation is generally preferred.
If you just take various oral cartilage nourishing and anti-inflammatory drugs to treat it, or use physical therapy, it can temporarily relieve the symptoms, but it does not treat the root cause of chondromalacia patellae.
Commonly used physiotherapy treatments include: drug ion introduction (anti-inflammatory and analgesic through the introduction of drug ions), ultrashort wave (high frequency electromagnetic field to achieve anti-inflammatory purposes), low and medium frequency electrotherapy (to improve circulation by improving cell membrane permeability), wax therapy (to promote local blood circulation) and so on. Of course, the specific treatment method, dosage, etc. should be arranged by a specialist physiotherapist in a specialized hospital. Home physiotherapy equipment will also have a certain effect, but the effect is relatively much worse.
Commonly used oral medications include cartilage nutrients, such as Vibram, Glucophage, and others. There is another category of drugs that require intra-articular injections for cartilage nutrition and joint lubrication, such as Permethrin and Argile. These drugs need to be injected directly into the joint by a professional doctor to be effective.
Of course, in the treatment of chondromalacia patellae, exercises for leg strength, especially for the quadriceps, are central to the rehabilitation and improvement of function and prevention of relapse.
The muscles surrounding the knee joint (especially the anterior thigh muscle group, the quadriceps) are important structures that maintain the stability of the knee joint. In patients with osteoarthrosis, the quadriceps muscles are not exercised because of decreased pain and activity, and they all atrophy significantly. This decreases the stability of the knee joint, causing the patellofemoral and femoral-tibial joints to produce unsuitable groove motion and excessive frictional impact, which can further aggravate the development of osteoarthrosis. (At the same time, studies have shown that the quadriceps muscle is selectively inhibited in osteoarthrosis of the knee, and the N cord muscle is not affected as much. In layman’s terms, the muscles in the front of the thigh atrophied greatly, and the muscles in the back did not have much of a problem for a short time.)
The common method of exercising the quadriceps is the straight leg raise and the static squat.
Straight leg raise exercise
Lie flat on your back, first straighten your leg with maximum strength, and then lift your leg to a height of about 15 cm from the bed with your heel. Note that the knee joint must be straight, so as to fully mobilize the quadriceps muscle fibers, you can test them separately, straight lift and slightly bent lift, with the power of the difference is very large, you can also see the degree of muscle contraction is also very different.
After practicing for a period of time, the strength improved, you can switch to sitting exercises. It is to sit up straight on the bed, and then in the straight lift legs. Because after sitting up the hip flexed up, iliopsoas muscle relaxed, not involved in contraction does not help the quadriceps, so it is more tired, the muscles of the front of the thigh practice is also better.
The action requirements for the static squat are as follows.
The feet stand apart and shoulder width apart, the toes and knees are forward, the upper body is straight against the wall, the center of gravity falls on the heel. Knee joints in the vertical direction can not exceed the toe, the knee angle can not be greater than 90 degrees. Hold the sub-posture until exhaustion, rest for 10 seconds and then repeat, 10 consecutive times / group, 2-3 groups / day. Simply put, it is the back against the wall to practice “zama stance”!
If your symptoms are so severe that it hurts to squat at a small angle, you can use static weighted knee extension: sit on a high chair, bed or table with your knee hanging below the bed, tie a sandbag to your ankle and try to straighten your leg as hard as possible, holding it until exhaustion (that is, you can’t lift it anymore), 5-10 times/group, 2-3 groups per day.
Static resistance knee extension.
Sit on a high chair, so high that your feet can leave the ground without affecting the movement. Or on a hard bed (for stability), on a table, or on a special quadriceps exercise machine.
Tie an appropriately weighted sandbag to the ankle as a load. Straighten the knee joint, then add the weight of the bag as a load and hold it in a straight position to work the quadriceps. During the rest between each exercise, you can use your healthy leg to help support for a while, so that you don’t have to stimulate the joint by lifting and lowering the flexion and extension joints. Generally hold until exhaustion (that is, can no longer lift) count once, 5-10 times / group, 2-3 sets of exercises per day.
This method can be further developed into a “static resistance knee extension” with “multi-angle equal length exercises”! When extending the knee, kick the leg forward and hold it for 3-5 seconds against the weight of the sandbag until it is completely straight, counting as one complete movement.
Of course, all these exercises should be done gradually, from few to many, from easy to difficult, from static exercises in a stationary position to power exercises in motion, from simple to complex movements. The above introduction is only the most simple and easy, the safest basic exercises. Because too many excessive exercises not only can not relieve the symptoms, but even aggravate the damage to the cartilage. So without special guidance, it is better not to practice blindly by yourself.
In addition, it is more important to adjust the activities of daily life, not because of fear of pain is not moving at all, not to mention that as long as the exercise is better than not practicing, gritting the teeth to endure the pain hard to practice. Because under-exercise and over-exercise are counterproductive and can aggravate the condition!