Osteoarthritis is a non-inflammatory degenerative change of articular cartilage and the formation of osteophytes at the joint margins caused by aging or other factors such as trauma, congenital joint abnormalities, or joint deformities. Clinically, it can manifest as joint pain, limited mobility, and joint deformities. There are many commonly used synonyms, such as osteoarthrosis, degenerative joint disease, senile arthritis, and hypertrophic arthritis.

bubble_chart Epidemiology

Degenerative changes in cartilage may begin as early as the late stage [third stage] of the 20s. In individuals over 50 years old, most can exhibit signs of osteoarthritis on X-ray films. The condition is often more pronounced in women than in men, frequently affecting finger joints, knees, hips, and the spine, making it the most common cause of mobility impairment in the elderly.

bubble_chart Etiology

Primary osteoarthritis refers to joint lesions that occur with aging and are not associated with other diseases, while secondary osteoarthritis is caused by injuries, inflammation, genetic factors, and metabolic endocrine disorders. The classification by disease cause is shown in Table 22-5.

bubble_chart Pathological Changes

The pathological basis of this disease is the alteration of articular cartilage, generally believed to result from the wear and tear of cartilage exceeding its repair capacity. It commonly occurs in weight-bearing joints. In the early stages, microscopic examination reveals a reduction in chondrocytes, fatty degeneration, and changes in collagen fibers. Subsequently, numerous softening foci become visible on the cartilage surface, which loses its luster, turns yellow, and becomes rough. Fissures develop, followed by surface erosion and exfoliation, leading to exposure of the subchondral bone. The detached small fragments can cause synovial membrane inflammation. Simultaneously, the subchondral bone undergoes eburnation and thickening in areas subjected to the greatest pressure and wear, while osteophytes (commonly known as bone spurs) form at the ligament attachment sites along the cartilage margins. In peripheral areas with less pressure, bone atrophy occurs, presenting as osteoporosis on X-rays. Occasionally, variably sized cystic changes can be observed within the subchondral bone, resulting from mucoid and fibrinous changes due to microfractures of the trabeculae.

Primary osteoarthritis often develops after middle age, with its incidence increasing with age. The affected joints are generally weight-bearing joints and those frequently used. The main symptom is joint pain, which often occurs in the morning and may lessen slightly with movement. However, excessive activity can worsen the pain due to joint friction. Another symptom is stiffness in the affected joints, especially after maintaining a certain posture for a long time, requiring some time to regain flexibility. Weather changes often trigger symptoms. Multiple joints may be affected simultaneously, but unlike rheumatoid arthritis, it does not present as systemic symmetric polyarthritis. Examination of the affected joints may reveal grade I swelling, with friction or crepitus sounds during movement. In severe cases, muscle atrophy and joint deformities may occur.

The symptoms of this disease do not correlate with X-ray findings, and symptoms vary depending on the affected area.

1. **Hands:** Degenerative changes in the finger joints manifest as Heberden's nodes at the distal interphalangeal joints, most commonly in the middle and index fingers. Bouchard's nodes at the proximal interphalangeal joints are less common and are often mistaken for small wind-dampness nodules. Degenerative changes in the first metacarpophalangeal joint can cause pain in the radial side of the wrist, while other metacarpophalangeal joints are rarely affected. The occurrence of Heberden's nodes is related to genetics and gender, being more common in women. Most cases are not significantly painful but may involve limited movement and grade I numbness or stabbing pain. They can also lead to flexion and deviation deformities of the distal interphalangeal joints. In some rapidly progressing cases (often due to overexertion), acute redness, swelling, and pain may occur.
2. **Knee:** Primary osteoarthritis most commonly affects the knee joint. Patients often report crepitus sounds, pain while walking that improves with rest, and stiffness after prolonged sitting or standing, which eases with movement and muscle relaxation. Symptoms fluctuate in severity and may even vary daily. Joint swelling is often due to osteophyte formation or minor effusion, while acute swelling suggests intra-articular bleeding. As the condition progresses, restricted knee movement may lead to disuse muscle atrophy and even genu valgum or varus deformities.
3. **Spine:** The spine has two sets of joints: intervertebral discs and facet joints. In the cervical spine (C2–C7), there are also uncovertebral joints (Luschka joints). Primary osteoarthritis often results from degenerative changes in the intervertebral discs and nucleus pulposus dehydration after middle age, leading to narrowed disc spaces, osteophyte formation, and bone wear. Most cases are asymptomatic, but when symptoms occur, they vary in severity and are usually chronic. However, acute episodes may be triggered by injury, heavy lifting, or sudden spinal movements. In the cervical spine, osteophytes at the uncovertebral joint margins can compress cervical nerve roots exiting the intervertebral foramina, causing recurrent localized neck pain that may radiate to the forearm and fingers, along with numbness and reduced dexterity. Osteophytes at the posterior vertebral margins may protrude into the spinal canal, compressing the spinal cord and causing numbness and weakness in the lower limbs, followed by the upper limbs, or even quadriplegia. Compression of the vertebral artery may lead to symptoms of vertebrobasilar insufficiency. Degenerative changes in the thoracic spine are rare. In the lumbar spine, L4–L5 and L5–S1 are the most common sites for herniation of intervertebral discs, with symptoms including lumbago and sciatica, often triggered by sprains, heavy lifting, or bending. Physical examination may reveal localized tenderness, positive straight-leg raise test, and changes in sensation, muscle strength, and tendon reflexes. Secondary osteoarthritis of the spine is often caused by congenital spinal deformities, scoliosis, fractures, or bone subcutaneous nodules.
4. Hip: Primary osteoarthritis of the hip joint is relatively rare in our country and is often part of systemic degenerative joint disease, mostly occurring in individuals over 50 years old, with a higher incidence in males than females. Secondary cases are commonly caused by ischemic necrosis following femoral head or femoral neck fractures, congenital hip dislocation, rheumatoid arthritis, etc. The clinical manifestations mainly include hip pain, which may radiate to the groin, inner thigh, or even above the knee. Initially, the pain occurs during activity and weight-bearing, then progresses to become persistent, accompanied by a limping gait. When the condition becomes severe, the hip joint flexes and adducts, with compensatory lumbar lordosis, leading to severe lower back pain and even an inability to walk. Examination reveals local tenderness in the hip joint, limited mobility, and a positive "4" sign test.

Primary generalized osteoarthritis often occurs in menopausal women, involving multiple joints, particularly affecting the finger joints and the first metacarpophalangeal joint. It typically presents with an acute pain phase and can sometimes be confused with rheumatoid arthritis. After the acute symptoms subside, joint function is preserved.

Diffuse idiopathic skeletal hyperostosis is more common in elderly males, characterized by extensive osteophyte formation, sometimes fusing together. The clinical symptoms are less severe than the radiographic findings, with patients reporting grade I pain and joint stiffness but maintaining relatively good mobility. The radiographic diagnosis is based on three criteria: calcification or ossification along the anterior aspect of at least four contiguous vertebral bodies; absence of severe intervertebral disc degeneration; and vertebral marginal sclerosis. Extraspinal calcifications may also be observed, particularly large osteophytes at the olecranon and calcaneus.

bubble_chart Treatment Measures

There is no specific drug that can halt the progression of this disease, but comprehensive treatment measures are relatively satisfactory in alleviating pain and protecting joint function. In terms of treatment, it is first necessary to educate patients about the disease, teaching them how to protect their joints and avoid excessive pressure on them. Obese individuals should lose weight; incorrect postures should be corrected; appropriate exercise during stable periods can delay degenerative changes in the joints. When pain symptoms occur, the affected joints should be given adequate rest, and medications or other treatment measures should be applied, including the following aspects.

AD

TCM's treatment of atopic dermatitis is more comprehensive, fundamental, non-toxic and effective than Western medicine's symptomatic treatment

1. **Medication**: For patients with mild or grade II pain, non-steroidal anti-inflammatory drugs (NSAIDs) often have excellent anti-inflammatory and analgesic effects. The common side effect of these drugs is gastrointestinal reactions, which can cause ulcer bleeding and erosive gastritis. Therefore, they should not be taken continuously for long periods but intermittently. Taking the medication after meals or with antacids can reduce gastrointestinal reactions. These drugs are contraindicated in patients with active ulcers. Commonly used drugs include: - Indomethacin (25–50 mg, 2–3 times daily), which may cause gastrointestinal reactions, headache, dizziness, edema, and leukopenia. - Ibuprofen (0.2–0.4 g, 2–3 times daily), which has fewer gastrointestinal side effects but may occasionally cause rashes, leukopenia, or visual disturbances. - Piroxicam (20 mg once daily), which has a long duration of action. - Naproxen (250 mg twice daily). - Diclofenac (75–100 mg daily, divided into 2–3 doses). Adrenocorticosteroid drugs also have excellent anti-inflammatory and analgesic effects, but due to their significant side effects—such as hypertension, diabetes, gastritis, and water-sodium retention—they should only be used for severe pain patients who do not respond to other treatments, and must be administered under close medical supervision.
2. **Intra-articular injection**: Injecting 1 ml of hydrocortisone acetate with 3 ml of lidocaine or 0.5–1% procaine into the joint cavity once a week for four weeks as a course of treatment can often relieve symptoms.
3. **Physical therapy**: Heat therapy can alleviate symptoms for most patients. Paraffin wax therapy can be used for limbs, and diathermy can be applied to the spine and shoulders. Grade I tuina (massage) after heat therapy can reduce muscular rigidity and spasms.
4. **Traction therapy**: For patients with cervical spondylosis of the radicular type, cervical traction is quite effective. It can relax muscles, relieve pain, and prevent adhesions between nerve roots and adjacent tissues. However, the traction method and course must be appropriate and conducted under the guidance of a specialist. During and after physical therapy and traction therapy, appropriate physical exercises can be performed to enhance muscle strength and improve joint stability.
5. **Tuina and Chinese medicinals**: Traditional Chinese tuina therapy often shows significant effects in alleviating symptoms of this disease. Chinese medicinals aimed at dredging collaterals and relieving pain can sometimes also be highly effective.
6. **Surgical treatment**: For patients with intractable pain, unstable joints, or significant functional loss, surgical treatment may be considered, such as hip replacement, subtrochanteric osteotomy, or knee arthroplasty.

bubble_chart Differentiation

This disease should be differentiated from the following conditions:

1. rheumatoid arthritis: It mostly occurs in young women and is often accompanied by systemic symptoms. Generally, it is not difficult to differentiate from this disease. Misdiagnosis occurs because Heberden's nodes and Bouchard's nodes with finger deviation deformities can be easily mistaken for rheumatoid arthritis. However, the nodules in this disease rarely show inflammatory reactions, and the wrist joints and metacarpophalangeal joints are seldom involved, which are key points for differentiation. Occasionally, rheumatoid arthritis occurring in weight-bearing joints of the lower limbs with secondary osteophyte formation can easily be confused with this disease. In such cases, normal erythrocyte sedimentation rate, positive rheumatoid factor, and normal synovial fluid examination favor the diagnosis of degenerative joint disease.
2. ankylosing spondylitis (ankylosing spondylitis): The main symptoms include lower back pain, spinal stiffness, and limited mobility. The hip joints are also frequently affected, sometimes presenting symptoms similar to this disease. However, ankylosing spondylitis mostly occurs in young men, with the primary lesions at ligament attachment sites, gradually ossifying and leading to stiffness. In severe cases, the anterior and posterior longitudinal ligaments, interspinous ligaments, and others may ossify, causing the spine to resemble bamboo. The intervertebral discs are rarely involved, and the X-ray findings are distinctly different from those of degenerative spinal lesions.