When climbing stairs becomes difficult, walking downhill and cycling is painful, it is usually our knees that are to blame.
Pain in the knee is one of the most frequent reasons why people consult a doctor. For successful treatment, it makes sense to look at the causes of knee pain. The general assumption that cartilage damage or cartilage wear and tear, i.e. arthrosis, alone triggers the pain. However, this does not go far enough, because the cartilage itself has no nerves.
How pain develops in knee arthrosis
In order to find out the causes of knee pain, it is necessary to first take a look at the processes in the joint that lead to a degenerative joint disease, i.e. arthrosis.
The joint is a closed system in which the joint fluid circulates. This fluid (synovia) “lubricates” the joint and is responsible for the supply of important nutrients and the disposal of degradation products. When bending and stretching the knee, the synovial fluid is pumped through the joint and can thus supply all parts of the joint. The cartilage is also nourished in this way.
In arthrosis, the cartilage substance decomposes. This can be caused by wear and tear processes caused by overloading, malpositioning, injuries, or age. However, the cause of the reduction is initially inflammatory processes in the various joint structures. This is especially true at the inner skin of the joint capsule (synovial membrane), which produces the synovial fluid.
This produces tissue hormones that promote inflammation and are transported to the cartilage, where they promote cartilage degradation. Due to the loss of cartilage substance and cartilage quality (the cartilage becomes “brittle”), cartilage particles can splinter, which then cause injuries and irritations to the inner skin of the joint capsule.
This in turn reacts with inflammation-promoting tissue hormones, which as a result intensifies cartilage degradation – the “vicious circle of arthrosis” closes. The progression of cartilage degradation can be seen on X-rays. The joint gap, i.e. the distance between the bony structures, is increasingly reduced by cartilage degradation.
The inflammations in the joint also lead to fluid shifts, the so-called joint effusion. These swellings in the knee are visible and noticeable. The joint effusion restricts the mobility of the knee to a greater or lesser extent. As a result of this protective posture, the synovial fluid can no longer circulate sufficiently and the nutrition of the cartilage, which is already damaged, is reduced.
All these processes are involved in the development of acute and chronic pain in the knee.
58% of women and 52% of men report having had joint pain in the last 12 months.
Both acute pain and persistent (chronic) pain emanate from the joint structures that contain nerves. These include the inner skin of the joint capsule (synovial membrane); the meniscus, which contains nerves and blood vessels on the outside; the Hoffa’s fat pad, a circulated and extremely sensitive tissue with many nerves; the bones present in the joint, which can show painful changes, and the bone marrow, which can also be affected (lesions).
Acute pain usually occurs during certain movements when nerves in a region of the joint are mechanically stimulated. For example, splintered cartilage parts floating in the synovial fluid can irritate and injure the joint skin during certain movements, thereby triggering pain.
Inflammations are more likely to be responsible for chronic pain. The inflammation-promoting tissue hormones that are released continuously activate the pain receptors. The impulse is transmitted to the brain where it is perceived as permanent pain.
Acute and chronic joint pain is very common. In a survey, 29% of women and 24% of men reported having suffered from knee, hip or shoulder pain during the last 24 hours before the survey. In first place was the knee for about 17% of women and 15% of men.
The treatment of knee pain begins with the interruption of the inflammatory reactions.
Anyone who wants to interrupt the “vicious circle of arthrosis” must first stop the inflammatory reactions. Then a reconstruction of the cartilage structures can be attempted.
In addition to anti-inflammatory drugs such as diclofenac, which can be associated with severe side effects in the gastrointestinal tract, a number of natural substances are available. These include glucosamine, chondroitin sulphate, and special hyaluronic acid complexes. Although these “cartilage nutrients” are often dismissed by orthodox medicine, they now have strong scientifically based evidence of their effect.
Thus daily 800 mg of a qualitatively high-quality Chondroitinsulfats can improve the knee pain significantly and just as well as a pain reliever. Glucosamine is known to improve the water content of cartilage and also to prevent the formation of inflammatory tissue hormones. A special hyaluronic acid complex derived from cockscales, which is available under various brand names in Europe (Hyal-Joint®; Mobilee™), has been shown in studies to be particularly effective. Treatment with 80 mg daily significantly reduced both joint effusion and pain within 3 months.
A combination achieved 72% pain reduction in only 2 months.
Encouraged by the good data available on the individual substances, combination preparations to support joint functions are on the market. They are often combined with vitamins and trace elements (e.g. vitamin C, vitamin D, manganese) and other cartilage-protecting and anti-inflammatory substances (e.g. incense).
Some of these preparations also have their own studies. A placebo-controlled observational study with a combination preparation of glucosamine, chondroitin sulphate, hyaluronic acid (Hyal-Joint®), native collagen type II, vitamins and trace elements was used in persons with knee arthrosis (stage II and III) and achieved a pain reduction of 72 % after two months.
With herbal help to counter knee pain
Some plant extracts have proven effective in interrupting the inflammatory circulation in the joint and in rebuilding cartilage structures. The focus is on curcuma, among other things. Turmeric has strong anti-inflammatory and antioxidant properties and stops the cartilage-degrading metalloproteases, which are activated by inflammation.
The resin of the Indian incense tree (Boswellia serrata) is also an ancient remedy for joint problems. The boswellic acids it contains counteract inflammatory reactions. Researchers have also discovered that African devil’s claw (Harpagophytum procumbens) has an anti-inflammatory and slightly analgesic effect. The ingredient harpagoside probably plays the central role in this.
The rose hip, which is also used for painful arthrosis of the joints, comes from the home gardens. The fruits of the common hedge rose have anti-inflammatory effects, which are attributed to the galactolipids they contain. A cartilage-protective effect has also been proven for the galactolipids.
Conclusion
Knee pain is a widespread evil that immensely impairs the freedom of movement and the quality of life of those affected. However, natural substances are often an effective alternative to painkillers. Due to their good tolerability and the proven efficacy profile of chondroitin sulphate, glucosamine, hyaluronic acid, micronutrients, and plant extracts, these substances, individually or in combination, are now a widespread treatment option that many open-minded doctors and therapists support.
