What is Chondromalacia?

Sacral chondromalacia, also known as sacral chondritis, is a common knee joint disease that occurs in young adults. It is particularly common among athletes and sports enthusiasts, and the incidence is higher in women than in men. The main pathological changes are degenerative changes of cartilage, including swelling, fragmentation, and shedding of cartilage. At the same time, the corresponding lesions of the femoral condyle also develop the same, and develop into patellofemoral osteoarthritis.

Basic Information

nickname

Sacral chondritis

English name

chondromalacia patellae

Visiting department

orthopedics

Multiple groups

Young women

Common causes

Cartilage degenerative changes

Common symptoms

Pain behind the knee joint

Causes of sacral chondromalacia

Biomechanical factors

(1) Trauma theory Among the causative factors of patella osteomalacia, the theory of trauma is gradually recognized, including direct trauma, indirect trauma, and various physical stresses that repeatedly exceed the physiological range of joint cartilage, leading to the "thin shell structure" of The "arched structure" is destroyed, chondrocytes lose their protection and necrosis, and the synthesis of cartilage matrix is reduced, leading to the progressive destruction of articular cartilage.

(2) The metatarsal instability theory refers to the high metatarsal, low metatarsal, metatarsal tilt, and metatarsal subluxation or dislocation. Patella instability can cause increased pressure and abnormal distribution on the articular surface of the patella, causing cartilage damage.

(3) The progress of patellofemoral pressure theory in the biomechanics of patellofemoral joints has led to different understandings of the relationship between patellofemoral pressure and patellar softening. The impact of exposure to high pressure on patella cartilage softening is emphasized. However, it is difficult to explain the phenomenon that the medial side of the patella is a high incidence area of patella cartilage softening clinically with the theory of excessive pressure.

2. Biochemical factors

(1) Autoimmune theory The surface of articular cartilage can prevent anti-collagen antibodies from entering deep cartilage tissue and protect it.

(2) Cartilage dystrophy A variety of injury factors cause abnormal changes in the secretion of synovial fluid and its components, affecting the normal nutrition and physiological and biochemical processes of patellar cartilage, and promoting cartilage degeneration and pathogenesis.

(3) Cartilage lysis theory After the joint synovium is injured, the osmotic pressure changes, and the enzymes in the plasma increase into the synovial fluid, which increases the activity, and then dissolves the cartilage.

Clinical manifestations of patellar chondromalacia

Direct trauma to the knee can cause patella cartilage or osteochondral fractures, or cartilage degeneration due to multiple injuries, such as sports injuries, and the relative femoral articular surface is also damaged. The site of injury was mostly in the center of the sacrum. The disease mostly occurs in young adults and has a significant history of trauma or chronic cumulative small injuries. The main symptoms are pain behind the patella of the knee joint, which varies in severity. Generally, the symptoms of walking on flat ground are not obvious. Or the pain worsens after a long walk.

Examination of sacral chondromalacia

1. Patella crushing test

During the examination, the patella and its opposing femoral intercondylar joint surface are squeezed and ground or slide up and down, left and right, with rough friction, friction sound and pain and discomfort; or the examiner pushes the patella to the side with one hand and presses the patella with the thumb of the other hand Behind the edges can cause pain. In the case of effusions, the floater test can be positive.

2.Single-leg squat test

The patient was holding one leg and gradually squatted down to 90 ° 135 °. She developed pain and became weak. She could not stand on one leg after squatting.

3.X-ray inspection

According to the X-ray film of the knee joint, lateral position, and sacral tangent position, late cartilage wear can cause a large portion of the cartilage to wear, the gap between the sacrum and the femoral condyle becomes narrow, and there can be osteogenesis in the edges of the sacrum and femoral condyle.

4. Radionuclide inspection

During bone imaging examination, lateral radiography showed limited radioactive concentration of the sacrum, which is of early diagnostic significance.

Differential diagnosis of sacral chondromalacia

This disease needs to be distinguished from many diseases:

1. Congenital discoid meniscus hypertrophy;

2. Congenital dislocation of knee joint;

3. Medial and lateral meniscus injury;

4. Meniscal calcification;

5. Meniscal ossification;

6. Exfoliative osteochondritis;

7. Synovial chondroma disease;

8. Joint synovial fold syndrome;

9. Semitendinosus muscle, tendon slippage;

10. Symptoms of biceps femoris etc.

Sacral cartilage softening complications

The early symptoms are not serious, and the lesions continue to develop in a "hidden state" until the development of patellofemoral arthritis. In severe cases, the knee flexion and extension are limited and cannot stand on one leg. When iliofemoral osteoarthritis has developed in the late stage, the cartilage and subchondral bone in the lesion area have been significantly damaged, and the cartilage has no ability to regenerate and repair. In addition, meniscus injury and traumatic arthritis can be easily combined.

Treatment of patella chondromalacia

Non-surgical therapy

For those with mild symptoms, pay attention to avoid direct impact on the sacrum and reduce the sacrum friction activities, such as going up and down stairs, cycling, etc., the symptoms are expected to be reduced.

2. Surgery

(1) Sacral cartilage resection includes superficial cutting of cartilage, cutting cartilage to bone and bone drilling.

(2) After patellar arthroplasty cuts away the cartilage, the exposed bone (2 ~ 3cm) can be covered with the adjacent synovium or cutting a layer of fat pad.

(3) Sacral resection patients are older, with severe symptoms, larger exposed bone area (more than 3cm), and relatively large femoral ankle cartilage wear, and those who cannot be used for patellaplasty may consider patella resection.

Prevention of patella chondromalacia

Avoid prolonged, hard, rapid flexion and extension exercises. The occurrence of patellar osteomalacia has its internal and external factors for the elderly. The intrinsic factor is the degeneration of the articular cartilage itself, which is related to factors such as age. External factors are the chronic damage of articular cartilage caused by mechanical factors. The prevention of patellar osteomalacia mainly involves reducing the continuous pressure on the patellofemoral joints and improving the nutrition of cartilage.

1. Fully active joints

Under no load conditions. Such as lying on the bed to actively extend and flex the knee joint. Persist in the morning and evening, 10 minutes each time.

2. Prevent continuous pressure on the articular surface of the sacrum

The knees in flexed knees are under great pressure, which easily damages the articular surface. Avoid continuous squatting pressure on the metatarsal articular surface.

3. Plaster fixation or lower limb traction treatment

To actively perform quadriceps exercise, the quadriceps muscles can move the sacrum up and down, which is conducive to the nutritional penetration of the cartilage and reduce the continuous pressure on the patellofemoral joint surface.

4. Knee Discomfort or Painlessness

It is necessary to consider the possibility of early patella sclerosis, and to take timely rest and timely treatment to prevent the joint cartilage degeneration from aggravating.