Osteoarthritis of the knee, also known as degenerative osteoarthropathy and osteophytes, is an all-round, multi-level, chronic inflammatory disease with degenerative changes in the articular cartilage as the core, involving the bone and including the synovium, joint capsule and other structures of the joint; it is an aseptic, chronic, progressive disease that affects the knee joint and is very common in the middle-aged and elderly population.
I. Etiology and pathology
The disease is divided into two types: secondary and primary. Primary osteoarthritis is the most common, also known as idiopathic osteoarthritis, and is a chronic inflammatory disease. It has also been proposed that osteoarthritis is a repair process of synovial joints in response to various stimuli (including aging). Secondary osteoarthritis is also common, often secondary to joint deformity, joint injury, joint inflammation or other injuries, also known as traumatic arthritis.
Although the etiology of primary osteoarthritis is not fully understood, it is clear that many of the following factors can cause destruction of articular cartilage.
1, individual factors: the disease can be affected by both men and women, but is more common in women, especially women before and after menopause. From middle age to old age, the cumulative strain on the joints over the years as they age leads to degenerative changes in the articular cartilage. The incidence is higher in people with obesity and stout body type, which is due to overweight and increased weight bearing on the joints, contributing to the occurrence of the disease.
2, dietary factors: no blood vessels in the articular cartilage, its nutrition relies on the absorption from the joint fluid. Malnutrition can lead to and aggravate the progression of the disease.
3, immunological abnormalities: articular cartilage is a closed barrier without blood vessels, cartilage tissue is mostly in the body’s autoimmune surveillance system in isolation, in the synovial membrane of patients with primary osteoarthritis, a few monocytes, lymphocytes and plasma cells can be seen infiltration, and a large number of synovial cells with cytokine secretion function proliferation. Osteoarthritis may be a T-cell-dependent local inflammatory response process. Some scholars have found IgG, IgM and IgC in the superficial layer of hip cartilage in osteoarthritis, and the frequency of polyarthritis is higher in such patients.
4, climate factors: people who often live in wet and cold environments have a high incidence. This is mainly due to the low temperature, causing local blood flow slowdown or even obstruction. In addition, genetic factors caused by the abnormalities of the composition of the joint structure, especially the pathological aging of cartilage cells is also an important factor in the occurrence of this disease.
5, biomechanical factors: when walking in high heels, the function of the hip, knee and ankle joints are greatly altered due to torsion, and the hip and knee joints compensate to maintain a stable gait, resulting in damage to joint cartilage.
6, medical factors: the author confirmed through animal experiments that the long-term use of cortisol drugs, especially in the early treatment of pain, the use of cortisol drugs for painful injection or intra-articular injection, can cause serious secondary damage to the bone and joint.
Degeneration of articular cartilage is the most direct cause of osteoarthritis of the knee. Chondrocytes are the only cell type in mature cartilage associated with the repair of damaged cartilage tissue, and there is a significant decrease in chondrocytes in osteoarthritic articular cartilage of the knee compared to normal articular cartilage of non-osteoarthritic knees. The reduction in chondrocytes is closely related to the development of osteoarthritis of the knee. Cell death can lead to cell reduction, and cell death is divided into cell necrosis and apoptosis, and chondrocyte apoptosis has recently been observed to be present in osteoarthritic cartilage of the knee. Cartilage degeneration and wear, osteosclerosis, cystic degeneration, bone redundancy formation, and joint hypertrophy and deformation constitute the pathological core of osteoarthritis and lead to a series of clinical symptoms associated with it. The cartilage in the weight-bearing area of the joint becomes soft, the surface dries out, loses its luster and smoothness, becomes rough, yellow, less elastic, irregular pressure marks, nodules and linear grooves appear on the surface, or fibrous changes, the cartilage gradually becomes thinner and more fragmented, vertical fissures appear, so that small fragments of cartilage form on the surface and fall off in the joint cavity or float in place, and the subchondral bone is exposed after cartilage fragmentation and exfoliation. At the same time, the exfoliated cartilage fragments irritate the synovial membrane and joint capsule, causing congestion, edema, hyperplasia, hypertrophy, and increased synovial fluid, resulting in secondary synovitis. The synovial membrane can engulf the embedded cartilage fragments and make the synovial membrane hyperplasia, thickening and villi-like, and the joint capsule fibrosis and contracture.
II. Clinical manifestations and diagnosis
The main target organ of osteoarthritis is cartilage, and there is a lack of specific and sensitive diagnostic methods for early cartilage lesions. In recent years, “arthroscopy” or “chondroscopy” can be used to examine the joint cavity under direct vision, and if necessary, cartilage biopsy is feasible, and magnetic resonance imaging non-invasive technology can be used to examine articular cartilage, meniscus, synovial ligament and bony changes, which can be shown on three-dimensional images of early small bone fragments. However, these examinations are expensive and difficult to popularize, so the diagnosis of mid- to late-stage osteoarthritis is mainly based on clinical perceptions such as medical history, symptoms, and signs combined with x-ray findings of joint space narrowing, subchondral bone sclerosis, and bone superfluous formation.
Early diagnosis points.
Age, obesity, lower limb deformity (inversion of the knee is the most common deformity, which is related to the rounded and convex medial femoral condyle, the depressed medial tibial plateau, and the relatively lax bone with a weak medial meniscus), and limited joint movement (functional impairment caused by osteoarthritis can be divided into abnormal coordination of joint movement and reduced range of motion of joint flexion and extension. The vast majority of these are functional limitations, and it is rare to see a complete and permanent loss of joint function), swelling (caused by soft tissue degeneration and hyperplasia, synovial hypertrophy and fat pad enlargement due to joint effusion, or even osteophytes and bone growth. More commonly, two or three causes coexist.) etc.
Clinical manifestations.
1, pain: almost all cases have knee pain, the degree of pain is generally mild and moderate, a few are severe, occasionally severe pain or no pain. The pain is characterized by; initiation pain, weight bearing pain, active activity pain and rest pain. The pain is mostly related to temperature, air pressure, environment and emotion, and is aggravated in autumn and winter and when the weather changes. The pain is mostly located between the patella and the femur or around the patella and the medial side of the knee joint.
2. Swelling and deformity: due to joint effusion, soft tissue degeneration and hyperplasia (such as synovial thickening and fat pad enlargement), and osteophyte bone formation.
3.Dysfunction: change in coordination of joint activities, such as playing soft, slipping sensation, kneeling sensation. Reduced motor ability, such as joint stiffness, instability, reduced range of motion and reduced ability to live and work.
4. Physical signs: swelling, patellar tenderness, peripatellar tenderness, positive grinding test, positive knee extension test, positive unipedal half-squat test and positive X-ray examination: X-ray examination (standing frontal, lateral, patellar 45 degree image) joint space narrowing, subchondral plate sclerosis and bone redundancy formation are the basic X-ray features of osteoarthritis. In the early stages of osteoarthritis, when there are only degenerative changes in the cartilage, the X-ray may not show any abnormalities. As the articular cartilage becomes thinner, the joint space becomes progressively narrower, and the narrowing of the space can be disproportionately altered.
The severity of osteoarthritis can be classified into four degrees according to X-ray examination.
Degree 1: suspicious joint space narrowing and possible labral hyperplasia.
2 degrees: definite bone spurs and possible joint space narrowing.
degree 3: multiple moderate bone spurs and definite joint space narrowing, some sclerosis and possible bone end deformity
4th degree: large bone spur, significant joint space narrowing, severe sclerosis and definite bony end deformity.
Magnetic resonance imaging: transverse, sagittal and coronal planes using surface coils of the limb. It can show bone cortex, marrow tissue, articular cartilage, meniscus on both sides, cruciate ligament, fat pad, tendon, muscle, skin, adipose tissue, blood vessel, nerve bundle, etc.
III. Treatment
The current treatment of osteoarthritis aims at relieving pain, reducing inflammation, delaying cartilage degeneration, improving function, and avoiding or reducing deformity. In recent years, the progress of drug treatment has been faster and has achieved better results. In addition, intra-articular surgical treatment has also shown good prospects.
1. Non-surgical treatment (conservative treatment)
The cause of pain in osteoarthritis of the knee has not been clearly explained, but it is believed that there are two mechanisms: one is the direct stimulation of nerve endings located in the synovium, ligaments, bone, and joint capsule due to mechanical factors (meniscus, ligament, and osteochondral damage) caused by the breakdown of each constituent tissue of the joint, and the other is the stimulation of nerve endings due to the production of pain-causing substances for certain reasons.
(1) Physical therapy: It can release pain and muscle spasm, help improve blood circulation and reduce swelling. Hot compresses can be applied, preferably wet heat. Hot air baths and hot spring baths can also be applied. Heat transmission or ultrasound therapy can be used to relieve subacute pain, and induction electricity can be used for muscle atrophy. Ultrashort wave, microwave, iontophoresis have good effect of anti-inflammatory and pain relief. The conditions for warm mineral bath, whirlpool bath is more effective.
(2) acupuncture treatment: acupuncture points for the foot three li, Yanglingquan, Yinlingquan, the nasal, hedging, etc..
(3) massage therapy: the patient lies on his back and the operator rubs around the knee joint 20 times with both hands, then rubs the peripatellar pressure point 20 times with the thumb and then does the passive movement of the knee joint 5-10 times.
(4) Needle knife release treatment.
(5) Joint injection: local pain point injection and intra-articular injection, intra-articular injection of sodium vitrate has a good effect on early to mid-stage osteoarthritis.
Drug treatment
Western medicine treatment.
Non-steroidal anti-inflammatory analgesics: for ibuprofen, neproxen, fenbuterol, fotarine, etc. Drugs such as aspirin, anti-inflammatory pain, and Protaxon should be used with caution because of the large side effects. It is better to use drugs that relieve muscle spasm, such as clobetasone, shujangling, prednisone, fenadrol, etc. You can also add vitamin drugs, such as vitamin B, vitamin C, vitamin E, etc. Antibiotics should also be given in acute inflammatory phase with redness, swelling and pain.
Cyclooxygenase-2 selective inhibitors such as celecoxib (celecoxib, celebrex) and rofecoxib (rofecoxib, vanillo). Aminoglucans are an important component of glycoproteins, proteoglycans, mucopolysaccharides and other constituent parts of connective tissue. In osteoarthritis the production of proteoglycans cannot catch up with their loss and will lead to loss of cartilage matrix.
Herbal treatment.
Osteoarthritis is mainly characterized by joint pain and restricted movement, which can be classified as “paralysis” in Chinese medicine.
(1) Chinese herbal fumigation: 15 grams of each of the following herbal remedies: Xanthopodium, Turbinicarpus, Wailingxian, Papaya, Wujiapi, Niujian, Chuanjiao, Haidongpi, Liufenu, Fangfeng, and Thornybush, hot fumigation and warm washing of the affected area.
(2) Internal use of Chinese medicine: Shu Di, Shan Yao, Poria, Cornu Cervi Pantotrichum, Ze Di, Dan Pi, Wu Jia Pi, Cuscuta, Atractylodes Macrocephala, Citrus aurantium, and Radix et Rhizoma Polygonatum are used to strengthen the liver and kidney, and strengthen the muscles and bones.
(3) External application of traditional Chinese medicine: natural copper, Chuan, Cao Wu, cumin, gentiana, frankincense, myrrh, papaya, turmeric, Yuan Hu, Tu Yuan, etc. powdered and mixed with vinegar for external application
2.Surgical treatment
In recent years, the use of intra-articular surgical treatment for some patients with cartilage defects in the knee joint has shown good prospects. The main methods are osteotomy, free body removal, meniscectomy, synovectomy, articular chondroplasty and autologous cartilage transplantation and autologous osteochondral transplantation, arthroscopic surgery, etc.
In conclusion, osteoarthritis is a disease related to social and quality of life issues, we should have sufficient understanding of it, combined with early clinical diagnosis, integrated and individualized treatment. It is believed that with the progress of medical science and technology and the deepening of the understanding of this disease, there will be more and more effective treatment methods to relieve patients’ pain in the near future.