The physical examination begins when the physician meets the patient. The physician can assess posture, gait, skin texture, and gross muscle strength by shaking hands, accompanying the patient into the office, and watching him or her move. A comprehensive assessment of the musculoskeletal system includes inspection and palpation of joints and soft tissues as well as evaluation of joint range of motion and neuromuscular function.
Joint swelling, color, and alignment, as well as skin rashes and muscle wasting, are usually obvious in a glance. Comparing similar joints and muscle groups on opposite sides of the body helps detect subtle abnormalities.
The hallmark of inflammation is swelling, which, when present in a joint, indicates that arthralgia has become arthritis. An increase in synovial fluid causes generalized joint swelling unless fluid accumulates in a contiguous synovial pouch (eg, suprapatellar space) or bursa (eg, gastrocnemius-semimembranous popliteal bursa [Baker cyst]). Inflammation of a tendon sheath may cause soft, localized para-articular swelling. Soft tissue edema tends to be more diffuse.
Well-defined swelling over a bony prominence such as the olecranon process or patella may represent an inflamed subcutaneous bursa, a rheumatoid nodule, a gouty tophus, or rarely, a xanthoma or an amyloid deposit. Bony enlargements (osteophytes) adjacent to joints are typical of osteoarthritis and occur as a result of cartilage damage. Occasionally, such overgrowths are a product of chronic inflammation. Osteophytes may be palpable and visible at the distal interphalangeal and proximal interphalangeal (PIP) joints, where they are called Heberden and Bouchard nodes, respectively.
Acute inflammation of a joint may impart an erythematous hue to the overlying skin, reflecting vasodilation of cutaneous vessels. In some cases of crystal-induced disease, such as gout, the joint and surrounding areas have an intense red-violet color mimicking that seen in infectious cellulitis and septic arthritis.
Inflamed joints tend to assume positions that maximize intrasynovial volume, thereby minimizing intrasynovial pressure and reducing pain. In chronic arthritis, when such positions are held for prolonged periods, flexion deformities may ensue. Chronic arthritis can also lead to destruction of supporting structures with consequent malalignment of adjacent bones.
Atrophy of muscles may result from lack of use, neurologic disease, inflammation of an adjacent joint, or myositis associated with an underlying disease. Thus, atrophy of the intrinsic muscles of the hand commonly accompanies inflammation of the fingers or wrists and is visible as depressions between the extensor tendons on the dorsum of the hand. Similarly, synovitis of the knee typically causes atrophy of the quadriceps muscles, resulting in a concavity just above the knee, particularly on the medial aspect.
A “hands on” examination is vital to the detection of inflammation and structural damage in a joint.
Joint tenderness is the most ...