Relieve knee pain and travel without worries

Author: Qi Pan China Rehabilitation Research Center

Reviewer: Ma Lifeng, deputy chief physician, Beijing Friendship Hospital, Capital Medical University

Figure 1 Copyright image, no permission to reprint

As the saying goes, "When a person ages, his legs age first, and when a tree ages, its roots wither first." The knee joint is one of the largest joints and the most important weight-bearing joints in our body. It bears most of the weight of our body and is an important part of our walking, running, jumping and other movements. It is the most important "movement axis" and "load-bearing axis" of the human body. With age, the knee joint will inevitably wear out and degenerate. If you find that your knee joint gradually becomes painful in your daily life, especially when you go up and down stairs and squat, it is very likely that you have "knee osteoarthritis."

So what is knee osteoarthritis?

Osteoarthritis of the knee is a chronic bone and joint disease caused by degeneration of knee cartilage and bone hyperplasia. It is also called "proliferative arthritis of the knee", "degenerative arthritis and osteoarthritis, etc."

Figure 2 Copyright image is not authorized for reproduction

According to the seventh national census, my country has a population of over 264 million people aged 60 and above, and the incidence of knee osteoarthritis among the elderly population is as high as 50%, which means that more than 130 million elderly people suffer from knee pain. Knee osteoarthritis not only seriously affects the quality of life of patients, but also imposes a heavy burden on patients, their families and society.

What are the causes of knee osteoarthritis?

The first and most important factor is age. Knee osteoarthritis mostly occurs in middle-aged and elderly people, and its prevalence increases with age. If the human body is compared to a car, the knee joint is like the bearing of the car. Long-term operation and wear will make the bearing surface rough and even produce a "creaking" sound. This sound is clinically called "bone friction sound". If we hear a "creaking" sound when we squat or flex and extend the knee joint, it means that the cartilage of our knee joint has been worn away and the knee joint has "aged". When the cartilage on the surface of the knee joint and the meniscus between the joints degenerate and wear, the subchondral periosteum is exposed, and pain follows.

Secondly , body weight is the second most important factor affecting knee osteoarthritis. As one of the most important weight-bearing joints in the human body, the greater the weight, the greater the pressure on the knee joint, and the faster the wear and tear. This is like the same vehicle. The more and heavier the cargo it pulls, the more serious the wear and tear on the vehicle. Not only that, obese patients often have poor circulation and metabolism and relatively high blood viscosity, all of which are not conducive to the circulation and metabolism of the joints. Minor trauma and fatigue can easily cause some aseptic inflammation, causing hyperplasia and degeneration of the synovium, and can also induce bone hyperplasia, which is more likely to cause pain and limited mobility. These accelerate the aging and wear of the knee joints of obese patients.

Thirdly , the decrease in estrogen levels is also an important factor causing knee osteoarthritis. The incidence of knee osteoarthritis in women is often higher than that in men. Why is this? It is mainly determined by estrogen levels. We all know that women go through menopause around the age of 55, and estrogen levels drop drastically after menopause. The level of calcium ions in the body is positively correlated with estrogen levels, that is, when estrogen levels drop suddenly, calcium loss in bones will also increase greatly, resulting in a decrease in bone strength and accelerated wear.

Finally , a factor that is easily overlooked is the atrophy of the quadriceps. After the age of 30, the muscle mass of a normal person will decrease by 3% to 5% every 10 years, and after the age of 50, the muscle mass will drop sharply, with an average loss rate of 5% to 10% every 10 years. When you are around 60 years old, if you do not perform any interventional strength training, you may lose about 0.5 kg of muscle every year. The quadriceps, as the knee extension device, is the most important group of muscles in the knee joint. When the quadriceps become weak, the stability of the knee joint will decrease, and the abnormal impact of the knee joint will increase, which will easily cause synovitis and joint effusion, and further knee pain. Knee pain will lead to reduced or restricted activity, leading to further disuse atrophy of the quadriceps, thus forming a vicious circle and accelerating knee pain and degeneration. Therefore, many elderly patients with knee osteoarthritis have the symptom of "fear of squatting".

In addition, people at high risk of knee osteoarthritis also include those who kneel, squat, bend their knees, and bear weight for a long time. A history of knee trauma is also an influencing factor.

How to determine if you have knee osteoarthritis?

Joint pain and limited joint movement are the most common clinical manifestations of knee osteoarthritis. For patients suspected of knee osteoarthritis, do not do a magnetic resonance imaging right away. The first choice is an X-ray examination, especially for elderly patients. Weight-bearing X-ray examinations are particularly important for observing force lines and joint spaces. If necessary, CT, magnetic resonance imaging, or B-ultrasound examinations can be performed to further clarify the degree, location, and differential diagnosis of degeneration. The typical manifestations of knee osteoarthritis on X-rays are asymmetric narrowing of the joint space, osteophyte formation at the joint margins, and subchondral bone sclerosis and/or cystic changes.

If you have knee osteoarthritis, do you need to undergo knee replacement surgery immediately?

The answer is of course no! Only a very small number of patients with knee osteoarthritis require surgical treatment, and the vast majority can be relieved through non-surgical treatment. For the treatment of knee osteoarthritis, we must follow the principle of step-by-step treatment.

Figure 3 Copyright image is not authorized for reproduction

1. Basic treatment

Basic treatment is the first choice, including patient education, exercise therapy, physical therapy, and mobility support therapy.

Patients should control their weight, reduce movements that may damage the knee joint (going up and down stairs, squatting, climbing, etc.), and strengthen quadriceps strength training (straight leg raising training and wall squats, etc.). Doctors usually use physical therapies such as interferential current stimulation therapy and pulsed ultrasound therapy to relieve patients' pain symptoms.

For patients who have obvious lower limb muscle atrophy, walking exercise is not advisable. We recommend this group of people to do straight leg raising training for the quadriceps and small angle wall squats: lying flat or sitting, straighten the legs, raise them about 20 cm, and hover for 10 seconds, 20 as a group, 5 groups a day; lean against the wall, bend the knees slightly about 30 degrees (too much angle may cause knee pain and discomfort), 3 minutes a group, 5 groups a day. When the quadriceps strength is significantly improved, the stability of the knee joint will be enhanced, and at this time we can appropriately increase the walking distance.

2. Medication

For obese elderly people, the knee joints have obvious pain symptoms, and it is difficult to lose weight through exercise. It is recommended that these patients go to the weight loss clinic of the endocrinology department to achieve the goal of weight loss through a reasonable diet and necessary medication. Topical nonsteroidal anti-inflammatory drugs can be used as the first-line treatment for knee osteoarthritis. If the pain symptoms persist, oral nonsteroidal anti-inflammatory drugs can be selected. Intra-articular injection of lubricants such as sodium hyaluronate can relieve pain in the short term and is highly safe.

In addition, Chinese patent medicine and acupuncture can also be used to treat knee osteoarthritis.

3. Restorative treatment

Restorative treatments include arthroscopic surgery, cartilage repair surgery, force alignment surgery, etc. Arthroscopic surgery is effective in the short term for knee osteoarthritis with only pain symptoms, and there is no significant difference in the medium- and long-term efficacy compared with conservative treatment. Patients with unicompartmental osteoarthritis of the tibiofemoral joint with poor knee force alignment, especially young and middle-aged patients with a high level of activity, can choose high tibial osteotomy, supracondylar femoral osteotomy, or proximal fibular osteotomy.

4. Reconstructive treatment

For patients with severe knee osteoarthritis who are not effective in any intervention, knee resurfacing surgery (reconstructive treatment) can be chosen. Of course, the physician will fully consider the patient's specific situation, subjective wishes and expectations when deciding whether to perform knee resurfacing surgery. Only when the surgical indications are accurately selected can a good surgical effect be guaranteed.

In summary, for patients with knee osteoarthritis, on the premise of a clear diagnosis, physicians should fully respect the patient's wishes, conduct a comprehensive disease assessment, and adopt a stepped and individualized treatment principle, giving priority to basic treatment, and developing a treatment plan in combination with physical therapy, restorative therapy, and reconstructive therapy.

Relieve knee pain and make travel easier for our elderly.