Knee weakness
In our daily outpatient clinics, we often encounter patients who come to the clinic with “weakness in the knee”. When walking normally or going up and down stairs, they feel that their knee joints suddenly become weak and their legs become painful. In fact, there are many causes of weakness in the knee joint.
Joint sports injuries
Meniscal injury is one of the most common injuries. When the lower extremity is weighted, the foot is fixed, and the knee is slightly flexed, a sudden excessive internal rotation and knee extension or external rotation and knee extension (for example, in volleyball, the player suddenly turns and fishes to save the ball while defending) may cause a meniscal tear. Meniscal injuries can have significant walking tenderness, sometimes joint pain, limited motion, and popping when the joint moves.
Next is knee ligament injury. The stability of the knee joint is relatively poor when it is slightly flexed, and if it is suddenly subjected to external forces that cause valgus or inversion at this time, it may cause medial and lateral collateral ligament and cruciate ligament injuries. This causes instability of the knee joint and the injured leg does not feel as strong as it used to be. It is obvious that the injured leg has no strength, walking is more often soft, the knee joint has a feeling of misalignment, and there is some swelling.
Chronic joint disease
Injury of the infrapatellar fat pad, which fills the gap at the front of the knee joint and has the function of strengthening the joint stability and reducing friction. Fat pad strain can occur as a result of trauma or prolonged friction causing congestion, hypertrophy and inflammation of the fat pad and adhesions to the patellar ligament, resulting in limited knee motion.
This injury occurs in people over 30 years of age who walk, hike or squat frequently. Patients may feel pain in the knee joint that is tender and worsens when fully extended, but joint motion is not restricted. The symptoms are obvious after exertion.
Chronic synovitis and abnormal hypertrophy of synovial folds in the knee The synovial membrane is one of the main structures that make up the knee joint. Synovial cells secrete synovial fluid, which keeps the cartilage surfaces of the joint slippery and increases the range of motion of the joint.
The synovial membrane is damaged by trauma or overwork, resulting in synovial hyperplasia, and eventually “synovial entrapment,” in which the synovial membrane, which floats like watercress in the joint fluid, is suddenly squeezed between the joints. Patients may feel tenderness, pain, swelling, and pressure in the knee joint, and interlocking symptoms may occur when the synovial membrane becomes embedded in the joint.
Degenerative changes
Osteoarthritis of the knee is a condition that occurs in middle-aged and older women. When these inflammatory factors irritate the soft tissues around the knee, the muscles can suddenly go into spasm, causing the knee joint to become tender and sometimes there is a frictional sound when the joint is moved. The knee may develop an inversion deformity with medial pain.
In young people, cartilage lesions between the patella and the femur, most commonly known as “chondromalacia patellae”, are caused by uneven patellar cartilage surfaces and sometimes by congenital patellar dislocation, resulting in premature degeneration of the cartilage and defects, which can also cause the knee joint to become tender and some people lose their ability to play sports.
Countermeasures
In winter, the low temperature and the huge difference between indoor and outdoor temperature will cause the muscles and blood vessels around the knee joint to contract, which will easily cause abnormal joint movement resulting in a high incidence of knock-knees, so if you encounter this situation, the first thing is to reduce the amount of exercise and let the joint rest. The second is to keep as warm as possible, you can use hot compresses; early only occasionally occur, after rest, physical therapy, the symptoms can be reduced or disappear.
If later on the knee hit the soft leg often, the number of episodes increased, several times a month, or even several times a day, and the knee pain is obvious, resulting in limited activities. Then it is necessary to go to the hospital for a physical examination, a radiograph, or even an MRI to clarify the cause.
Knee tenderness is now treated with a reliable technique – arthroscopy, which has a very small lens attached to a light-guided fiber. Under anesthesia, a very small incision is made and inserted into the joint cavity for observation. Using an optical lens, the internal structure of the joint is observed, lesions are detected, and ruptures, exfoliation, defects and bone outgrowth and hyperplasia due to wear and tear are removed and repaired. The application of arthroscopy has greatly improved the accuracy rate of intra-articular injuries and diseases to over 98%.
By operating under direct arthroscopic vision, the arthroscopist surgically removes proliferated synovial soft tissue and bone spurs, and damaged meniscus is an immediate treatment. The surgical results are excellent, and complications and sequelae are relatively few. Patients are able to walk on the same day after surgery. The patient is usually discharged from the hospital 2 to 5 days after surgery. The wound heals on its own 5 to 7 days after surgery.
Currently, 2 to 3 million patients undergo arthroscopic surgery in the United States each year, with a success rate of over 95% and minimal complications. President Clinton performed an arthroscopic ACL reconstruction, and arthroscopic minimally invasive surgery is now the preferred method of joint disease diagnosis and treatment.
This arthroscopic surgery has proven to be less invasive and patients recover quickly. Therefore, if you have a weak leg, you should go to the orthopedic department of the hospital for a knee examination as early as possible to treat the knee lesion.