Osteoarthritis (OA) is a joint disease arising from different pathophysiological causes with manifestations of joint damage, mechanical stress, and loss of articular cartilage. A normal joint is composed of subchondral bone covered by a thin layer of articular cartilage. The interarticular space separates the adjoining subchondral bone and is cushioned with synovial fluid. Articular cartilage allows frictionless movement and uniform load distribution. Muscles, ligaments, and tendons surround the joint providing strength, maintaining stability, and absorbing load. However, there are several physiologic changes that lead to a weakened joint, instability with loss of dexterity, development of pain, and decreased mobility. Weight-bearing joints such as the knee and hip are mainly affected in osteoarthritis; however, joints of the hand, foot, lumbar, and cervical spine may also be involved.
Patients with osteoarthritis present with joint pain and tenderness, limited mobility, instability, and crepitus with joint movement. Symptoms may progress from absence of pain, to joint pain upon movement relieved by rest, to pain with rest. Advanced disease will manifest with joint space narrowing, formation of new bone at joint margins (osteophytosis), and subchondral sclerosis on radiographs. Risk factors associated with osteoarthritis include advanced age, female gender, genetics, obesity, history of joint trauma, repetitive movement, misalignment, and quadriceps weakness. Diagnosis of osteoarthritis is based on patient history, physical examination, radiographic evidence, and laboratory testing. The American College of Rheumatology criteria for classification of osteoarthritis of the knee and hip share common elements including age older than 50 years, joint-specific pain, and joint stiffness. Diagnosis of knee or hip osteoarthritis also includes bone tenderness and enlargement with radiographic evidence of osteophytes. Pain with internal rotation of the hip joint validates osteoarthritis diagnosis. Hard tissue enlargement, swollen joints, and deformity in addition to hand pain with aching or stiffness are criteria used to diagnose osteoarthritis of the hand.
Addressing risk factors such as obesity with weight loss, potential joint injury with joint protection, and muscle weakness with exercise are strategies for the prevention of osteoarthritis. Increased body mass is associated with muscle weakness, altered gait, decreased function, and fall risk. Weight loss may reduce the probability of developing osteoarthritis. Joint injury predisposes patients for osteoarthritis later in life. Current treatment of injury in those without osteoarthritis may include surgery, joint rehabilitation, and muscle strengthening. Regular physical activity and muscle strengthening through resistance exercise in those without osteoarthritis may be a preventative strategy. Because muscles provide movement, absorb load, and stabilize the joint, strengthening can improve muscle function.
Treatment goals for OA include disease state awareness, relieving pain and stiffness, improving musculoskeletal movement and function, and protecting affected joints. These goals are accomplished by lifestyle changes, orthotics, physical and occupational rehabilitation, and pharmacologic therapy. Regular contact should be established with the patient through office visits or telephone contact to discuss pain status, compliance with pharmacologic and nonpharmacologic treatment, adverse ...