What Causes Knee Popping?

The knee joint is one of the largest joints in the body, consisting of the femur, tibia, and sacrum. It is the load-bearing joint of the human body and one of the most vulnerable joints. The knee joint is the joint with the highest incidence in the whole body. Pain in the knee joint is not only related to various injuries in the joint, but also often caused by various extra-articular factors. The symptoms of the knee joint are often non-specific. Symptoms such as pain, soft legs, and interlocking can be caused by cruciate ligament or meniscus injury, but also by patellofemoral joint abnormalities, articular cartilage lesions, or even just by abnormal hyperplasia of the synovial membrane . Knee joint disease mainly includes: osteoarthritis, synovitis, patella softening, meniscus injury and so on.

Basic Information

English name

gonarthrosis

Visiting department

orthopedics

Common causes

Chronic strain, obesity, bone density, trauma, stress tolerance, synovitis, patella sclerosis, meniscus injury

Common symptoms

Osteoarthritis, synovitis, patellar softening, meniscus injury

Contagious

no

Common types of knee disease

Osteoarthritis

Osteoarthritis is a chronic joint disease characterized by degeneration, destruction, and osteogenesis of articular cartilage. Also known as proliferative knee arthritis, senile knee arthritis. Clinically, it is most common in middle-aged and elderly people, with more women than men. The pathological features are degenerative changes in articular cartilage, focal subchondral bone density (sclerosis), marginal osteochondral osteophyte formation, and joint deformities.

Synovitis

Synovitis of the knee joint It refers to a kind of non-infectious inflammatory reaction disease that causes synovial injury or rupture when the knee joint is acutely injured or chronically strained, resulting in blood or fluid in the knee joint cavity. Can be divided into acute traumatic synovitis and chronic traumatic synovitis. Acute traumatic synovitis occurs in young people who love sports; chronic traumatic synovitis occurs in middle-aged and elderly people, obese people, or people who have used knee joints to bear weight.

3. Patella softening

Patella cartilage softening disease is caused by chronic injury of the patella cartilage surface, the cartilage swells, cracks, breaks, invades, and falls off. Finally, the opposite pathological changes of the femoral patella cartilage also occur, resulting in osteoarthrosis of the patellofemoral joint.

4. Meniscus damage

Meniscus injury is one of the most common injuries of the knee, more common in young adults, more men than women.

Causes of knee joint disease

Osteoarthritis

(1) Chronic strain has long-term poor posture, exerting heavy load, and being overweight, resulting in knee soft tissue damage.

(2) The increase in obese weight is directly proportional to the incidence of knee osteoarthritis. Obesity is also a contributing factor. Weight loss in obese people can reduce the incidence of knee osteoarthritis.

(3) Bone density When the subchondral bone trabecula becomes thinner and stiffer, its tolerance to pressure is reduced. Therefore, the risk of osteoarthritis in osteoporosis increases.

(4) Trauma and force can withstand frequent knee joint injuries, such as fractures, cartilage and ligament injuries.

Synovitis

When the knee joint is directly hit by violence, chronic long-term weight-bearing strain, indirect knee sprain, injury during surgery, strenuous physical activity or super-strength training, incorrect habits, joint degeneration, knee retension, and even wear Improper shoes can cause injury to the injured synovium, synovial hyperemia, swelling, and synovial cells actively produce a large amount of fluid, which contains plasma, white blood cells, and phagocytic cells. Normal joint synovial fluid is an alkaline fluid. Due to the increased exudation after injury, acidic products accumulate in the joint, and the synovial fluid becomes acidic, which promotes the precipitation of cellulose. If the fluid is not cleared in time, the joint synovial membrane will stimulate inflammation for a long time, prompting The synovium gradually thickens, and there is fibrosis, which causes adhesions and affects the normal movement of the joints.

3. Patella softening

(1) Congenital zygomatic dysplasia.

(2) Long-term wear of the knee joint is a common cause of this disease.

(3) The synovial fluid composition is abnormal due to various reasons.

4. Meniscus damage

Meniscus injuries are mostly caused by torsional external forces. When one leg bears weight and the calf is fixed at semi-flexion, the body and femur suddenly rotate internally. The medial meniscus is between the femoral condyle and the tibia, and is subject to rotational pressure, resulting in menis The board is torn. The greater the degree of flexion of the knee joint at the time of a sprain, the more the torn part is posterior. The mechanism of lateral meniscus injury is the same, but the direction of the force is opposite.

Knee joint disease diagnosis

Osteoarthritis

(1) The knee has a history of repeated strain or trauma.

(2) It is more common in the elderly, and the symptoms are gradually aggravated, which can suddenly increase due to fatigue and trauma. Exclude rheumatism, rheumatoid arthritis, severe knee trauma (such as fractures, meniscus injuries, etc.), lower limb deformities and joint infections.

(3) Knee joint pain and stiffness, which is more obvious when getting up in the morning, relieved after movement, increased in activity for a long time, and relieved symptoms after rest.

(4) There are typical symptoms of knee pain with limited joint movement. Pain up and down stairs and knee pain in half squatting position worsened.

(5) The following typical symptoms are: swelling of the knee joint, sometimes tenderness or throbbing pain in the medial and lateral joint gaps; bounces of joint movements, joint contracture or quadriceps atrophy.

(6) X-ray film, showing hyperplasia of bone and joint edges, narrowing of joint space, calcification of ligaments, sharpening of interstitial spurs of tibia, sometimes osteoporosis, and sometimes free bodies in joints.

Synovitis

For those who have multiple knee effusions or who have repeated effusions, joint effusions can be performed. It can reflect the nature and severity of synovitis. Therefore, joint puncture and synovial fluid examination have important reference value for the diagnosis and differential diagnosis of knee synovitis.

3. Patella softening

The main basis for diagnosing patella softening is pain behind the patella, which is caused by the patella crush test and the single-leg squat test.

4. Meniscus damage

Tenderness at the knee space is an important basis for meniscus injury.

(1) Most patients have a history of knee sprain.

(2) When the knee joint is extended and flexed, there is a popping sound in the knee.

(3) Quadriceps atrophy, tenderness in the knee joint space can be found during the examination, and the knee joint cannot be overextended or flexed.

(4) Meniscus bounce test and grinding test were positive in some cases.

Clinical manifestations of knee joint disease

Osteoarthritis

(1) Slow onset, more common in middle-aged and obese women, often with a history of exertion.

(2) The pain worsens during knee movements, which is characterized by paroxysmal pain at the beginning and continuous afterwards, even more at night after exertion, and pain when going up and down stairs.

(3) Knee joint movement is limited, and even lame. Very few patients may develop interlocking or knee fluid.

(4) There may be popping and friction sounds when the joint is moved, and joint swelling of some patients may cause joint deformities to be seen for a long time.

(5) Knee joint pain is a common complaint for patients with this disease. Its early symptoms are pain when going up and down stairs, especially when going downstairs. It appears alternately unilaterally or bilaterally. It is caused by joint enlargement, which is mostly caused by bony hypertrophy, and it can also cause joint fluid. Synovial hypertrophy is rare. In severe cases, varus deformities occur.

Synovitis

(1) Knee joint hematoma if it is an acute injury. Joint hematomas usually occur immediately or within 1 to 2 hours after the injury, and there are extensive blood stasis spots on the knees and lower legs. Tension was felt on the skin or swelling at palpation, and the buoyancy test was positive. There are often systemic symptoms, such as fever caused by blood stasis, and localized heat. This disease is often a complication of other injuries. It should be checked carefully in clinical practice to prevent missed diagnosis.

(2) Chronic strain or traumatic knee synovitis is caused by the improper management of acute knee synovitis and becomes chronic. It is clinically more common in the elderly, people with wet constitution, or with varus or varus of knees. Or other patients with knee deformities, or those with knee osteoporosis.

3. Patella softening

It is more common in young athletes. The initial stage is pain under the metatarsal bone, which is relieved after a little activity, and then aggravates after a long period of exercise, and gradually disappears after rest. Second, the tenderness of the sacrum edge, squeezing or pushing the sacrum with the knee extended can have a feeling of friction, with pain. When patellofemoral joint osteoarthritis is formed at a later stage, synovitis may occur secondary to joint effusion. Elderly patients may develop quadriceps atrophy.

4. Meniscus damage

More than half of the cases have a history of "sprained" knee joints with swelling, pain, and dysfunction of the knee joint. Pain is a common manifestation. It is usually limited to the side of the meniscus injury. Individual lateral meniscus tears may be accompanied by medial pain. Some patients may feel the noise and tear in the joints, and the knee joints cannot be fully straightened. Extensive pain in the knee is mostly related to the swelling of the synovium due to effusion or hemorrhage in the joint. This pain can be gradually reduced, but it cannot disappear. Swelling is seen in most patients. Swelling is severe at the beginning of the injury. Over time, the swelling gradually subsides, and swelling decreases afterwards.

Knee Joint Treatment

Osteoarthritis

(1) Non-surgical treatment (conservative therapy) includes physical therapy, medicine, injection therapy, and traditional Chinese medicine treatment.

(2) Surgical treatment

1) Knee arthroscopy exploration and cleanup This technique is a relatively safe and practical new technology for the diagnosis and treatment of knee joint diseases, which makes the patient less painful, less complications, quick recovery, and significant effects.

2) Knee replacement artificial knee replacement is to replace part or all of the damaged knee joint with artificially manufactured joint parts through surgery. It is to remove the worn and damaged articular surface and implant the artificial joint to return to normal. Smooth articular surface.

Synovitis

(1) Puncture therapy When there is a lot of joint effusion and high tension, joint puncture can be performed. The effusion and hemostasis can be completely removed, and sodium hyaluronate can be injected into the joint cavity. It is the main component of joint synovial fluid.

(2) Traditional Chinese medicine therapy has a series of advantages such as slow precipitation, long-lasting effects, and tangible local effects.

(3) Early fixation and exercise therapy should rest in bed, raise the affected limb, can be bandaged with elastic bandages, and weight bearing is prohibited. During the treatment, the quadriceps muscles can be exercised. The flexion and extension of the knee joint should be strengthened in the later stage. This will eliminate joint effusion, prevent quadriceps atrophy, and prevent recurrent synovitis.

3. Patella softening

Mainly non-surgical treatment: braking, physical therapy, anti-inflammatory, joint cavity closure, etc., strict non-surgical treatment is invalid or congenital malformations, feasible surgical treatment.

4. Meniscus damage

In the acute phase, if there is obvious effusion (or hemorrhage) in the joint, the effusion should be removed under strict aseptic operation; if the joint has "interlock", the method should be used to lift the "interlock". If the non-surgical treatment is ineffective, the symptoms and signs are obvious, and the diagnosis is clear, the injured meniscus should be removed early to prevent traumatic arthritis.

Knee joint disease prevention

1. Keep your knees warm. Wear trousers as much as possible. Do not expose your knees to cold air.

2. Can be applied hot. To improve blood circulation, reduce knee discomfort, relieve knee pain and muscle cramps, and reduce swelling. Hot compresses are preferably wet compresses, such as hot air bath, hot spring bath, mineral bath, whirlpool bath. A hot towel can also be used for wet compresses, but care should be taken if the joints become red and swollen. Hypertension and heart disease should be used with caution, especially when the temperature is high in summer (stop the hot compress in the acute phase).

3. It is necessary to combine work and rest, avoid excessive weight bearing on the joints, stay in a certain position for a long time, especially less than 90 °, and do not sit or stand for long. Joints should be properly moved, such as swimming more, insisting on riding more bicycles, walking less, especially walking up and down steps and uneven roads.

4. For obese people, they should abstain from diet, reduce weight, reduce joint load, and eat more foods containing protein, vitamins and minerals.

5. Correct the bad posture as much as possible, use cane and crutch to reduce joint load.

6. Reasonable use of braces, splints, knee pads, elastic adhesive tapes, and increase joint stability.

7. Strengthen massage and massage around joints. There are many ways: push, hold, roll, spin, rub, roll.

8. Strengthen knee strength exercises.

9. Strengthen knee range of motion training. If knee pain affects normal life, it is necessary to go to the hospital for examination and treatment.