Articular cartilage consists of collagen fibers, glycoproteins, and hyaluronan aggregated into a 1-2mm thick layer. When hydrated, it functions as a cushion to absorb and distribute weight-bearing and mechanical forces. Under physiological conditions, articular cartilage relies on the contraction of surrounding ligaments and the underlying bone to fully accomplish these tasks.Muscle contraction not only drives joint movement but also functions like a rubber band, absorbing significant impact forces to protect the joint. During accidents (e.g., falls), muscles cannot immediately initiate protective responses to sudden shocks, increasing joint load and potentially causing injury.Furthermore, muscle aging and peripheral neuropathy significantly diminish the muscles' energy-absorbing capacity. Another factor assisting cartilage in bearing weight is the subchondral bone, which exhibits a reticular distribution. Though softer than cartilage, it is firmer than cortical bone, endowing it with high elasticity that facilitates pressure absorption.
Osteoarthritis predominantly arises in two scenarios: first, when abnormalities exist in articular cartilage, subchondral bone, or surrounding muscles—such as age-related degeneration, osteoporosis, inflammation, or metabolic disorders; second, when these structures are normal but subjected to excessive stress due to obesity or trauma.
Pathology: Cartilage deformation occurs earliest and exhibits characteristic lesions. Loss of glycoproteins within the cartilage matrix causes softening of the superficial layer. Fractures develop under pressure points, resulting in a fine velvety appearance on the cartilage surface.Subsequently, cartilage gradually sloughs off in sheets, thinning or even disappearing entirely. Subchondral bone develops microfractures and necrosis, while proliferation of the articular surface and surrounding bone forms radiographic osteosclerosis, osteophytes, and cystic changes.The synovial membrane may exhibit mild proliferative changes due to cartilage and bone destruction, along with the shedding of metabolic debris into the joint cavity. These changes include synovial cell proliferation and lymphocytic infiltration, though their severity is far less pronounced than in rheumatoid arthritis. In severe osteoarthritis, the joint capsule wall shows fibrosis, and surrounding tendons may also be affected.
Clinical Diagnosis
No specific laboratory tests exist for this condition, but these findings aid in differential diagnosis from other diseases. Erythrocyte sedimentation rate (ESR) is normal in most patients, C-reactive protein (CRP) is not elevated, and rheumatoid factor is negative. Synovial fluid appears yellow or straw-colored with normal viscosity and normal coagulation tests. White blood cell count is below 2×10⁹/L, and glucose content rarely falls below 50% of blood glucose levels.
Joint radiography aids diagnosis. Affected joints exhibit the following radiographic changes depending on disease severity: 1) joint space narrowing; 2) subchondral sclerosis; 3) osteophytes along joint margins; 4) cystic changes in subchondral bone, with rare cases showing boat-shaped bone changes;5. Bone deformities including flattening of the femoral head and/or joint subluxation. It should be noted that many individuals with these radiographic changes lack clinical symptoms of the disease.
Diagnosis and Differential Diagnosis The American College of Rheumatology (ACR) classification criteria for osteoarthritis are as follows:
(1) Hand Joint Criteria: Hand joint pain or stiffness accompanied by at least three of the following four criteria.
1. Hard tissue hypertrophy in 2 or more of the following 10 joints: distal and proximal interphalangeal joints of the 2nd and 3rd fingers bilaterally, and the first carpometacarpal joint.
2. Hard tissue hypertrophy in at least 2 distal interphalangeal joints.
3. Involvement (swelling) in fewer than 3 metacarpophalangeal joints.
4. Deformity in at least 1 of the 10 joints listed above.
4. At least one deformity in any of the 10 joints listed above.
(II) Knee Joint Criteria Knee pain with radiographic evidence of osteoarthritis, accompanied by any one of the following:
1. Age > 50 years.
2. Knee stiffness < 30 minutes.
3. Presence of crepitus.(III) Hip Joint Criteria: Hip pain accompanied by at least two of the following three: 1. Erythrocyte sedimentation rate (ESR) < 20 mm/1st hour 2. Radiographic evidence of osteophytes on the femur or femoral head 3. Radiographic evidence of at least one joint space narrowingPatients with existing cervical spondylosis may consider the highly effective Chinese herbal permeation therapy method using Kangjian Life Health Mall's middle-aged and elderly health supplement—Joint Flexibility Essence. Its proteoglycan sulfate (composed of proteoglycans, collagen protein, and chondroitin protein powder) generates new cell nuclei and cell membranes upon entering the body, promoting intercellular connections and repairing aged or damaged cartilage. It demonstrates significant efficacy for arthritis and rheumatoid arthritis.These proteins initiate new cell creation within the body, form cell membranes between cells, enhance intercellular connections, replenish damaged or aged cartilage, and nourish and regenerate cartilage. This process effectively prevents cartilage wear and significantly improves existing arthritis and rheumatoid arthritis conditions.Many patients suffering from rheumatoid arthritis, osteophytes, cervical spondylosis, frozen shoulder, lumbar disc herniation, and synovitis have experienced the benefits after one course of Joint Flex. As advertised: "Climbing five flights of stairs in one breath is no effort at all."