General Approach to Arthritis and Joint Pain

Shoulder pain is considered chronic when present for > 6 months. Common conditions resulting in chronic shoulder pain include rotator cuff disorders, adhesive capsulitis, shoulder instability, and joint arthritis. Shoulder pain can be intrinsic or extrinsic to the joint. The potential of serious causes of referred pain to the shoulder such as cardiovascular and abdominal etiologies should be considered. A focused history and physical examination is essential and should include inspection, palpation, range of motion (ROM), and provocative testing. Imaging often includes plain radiographs occasionally supplemented with MRI. Management varies related to specific disorders and frequently requires physical therapy.

The shoulder complex comprises the glenohumeral joint, sternoclavicular joint, acromioclavicular joint, and the scapulothoracic articulation, and connects the upper limb to the trunk. This group of joints consists of the clavicle, scapula, and humerus bones, multiple muscles and supporting ligaments, cartilage, and bursae. The muscles ensure the mobility and stability of the shoulder and upper limb and are divided into 3 groups: anterior axioappendicular, posterior axioappendicular, and scapulohumeral muscles.

Rheumatoid arthritis (RA) is a symmetric, inflammatory polyarthritis and chronic, progressive, autoimmune disorder. Presentation occurs most commonly in middle-aged women with joint swelling, pain, and morning stiffness (often in the hands). Systemic inflammation can lead to extraarticular manifestations such as rheumatoid nodules, interstitial lung disease, Felty syndrome, and pericarditis. Prolonged and severe disease can lead to irreversible joint deformities. Diagnosis is based on strong clinical suspicion and confirmed by the presence of rheumatoid factor (RF), anti-cyclic citrullinated peptide (anti-CCP) antibodies, and characteristic imaging. Management involves long-term disease-modifying antirheumatic drugs (DMARDs), biologic agents, and physical therapy. Glucocorticoids and nonsteroidal antiinflammatory drugs (NSAIDs) are the treatment of choice for acute exacerbation.

Osteoarthritis (OA) is the most common form of arthritis, and is due to cartilage destruction and changes of the subchondral bone. The risk of developing this disorder increases with age, obesity, and repetitive joint use or trauma. Patients develop gradual joint pain, stiffness lasting < 30 minutes, and decreased range of motion. Physical exam may reveal crepitus with joint motion and osteophyte formation (Heberden's and Bouchard's nodes). The diagnosis is clinical and supported with radiographic joint findings. Management includes conservative measures, analgesic medications, glucocorticoid intra-articular injections, and surgery for advanced disease.

The arm is the region of the upper limb that extends from the shoulder to the elbow joint and connects inferiorly to the forearm through the cubital fossa. It is divided into 2 fascial compartments (anterior and posterior) and houses numerous structures, including the humerus; the brachial and profunda brachii arteries; the basilic, cephalic, and brachial veins; the radial, median, ulnar, and musculocutaneous nerves; and the flexor and extensor muscles of the arm.

Gout is a heterogeneous metabolic disease associated with elevated serum uric acid levels (> 6.8 mg/dL) and abnormal deposits of monosodium urate in tissues. The condition is often familial and is initially characterized by painful, recurring, and usually monoarticular acute arthritis, or “gout flare,” followed later by chronic deforming arthritis. The kidneys can also be affected, and urate crystals can precipitate as chalkstone-like deposits (“tophi”) in the soft tissues, synovial tissues, or in bones near the joints. Hyperuricemia is due to overproduction and/or underexcretion of uric acid and is a necessary but insufficient precondition to developing urate crystal deposition disease (most hyperuricemic individuals never experience clinical gout). The most commonly involved joint is the first metatarsophalangeal joint. The identification of urate crystals in joint aspirate or tophi is diagnostic. Effective therapies to relieve the pain of a gout flare include nonsteroidal anti-inflammatory drugs (NSAIDs), colchicine, and glucocorticoids; the choice of therapy depends on the individual and if there are any contraindications.