Hand arthritis

Examination and functional assessment

To assess the condition of the small joints of the hands, the patient must perform several active movements: clench the hand into a fist, fully extend all fingers, and oppose the thumb to the other fingers. If the range of motion is restricted, the physician checks passive movements.

Normally, the joint configuration is unchanged, movements are painless and performed in full. In pathology, visual inspection reveals swelling, skin redness, deformations, or atrophy of the surrounding muscles. Pain and crepitus (crunching) may be detected upon palpation and movement.

Differential diagnosis of hand lesions

The clinical picture directly depends on the underlying disease:

• Osteoarthritis (OA): Most commonly affects the hands and the bases of the thumbs. A characteristic sign is the formation of firm Heberden's nodes (on the distal interphalangeal joints) and Bouchard's nodes (on the proximal ones).
• Rheumatoid arthritis (Rheumatoid arthritis): Manifests as symmetric involvement of the metacarpophalangeal and proximal interphalangeal joints. Morning stiffness is typical. Pathogenesis includes the development of productive synovitis, which leads to cartilage destruction, deformation, and, ultimately, ankylosis.
• Systemic lupus erythematosus (SLE) arthropathy: Subluxations (subluxation) and joint malalignment (malalignment) of the interphalangeal joints and the thumb metacarpophalangeal joint are observed. A key difference is the absence of erosive changes on the articular surfaces.
• Sarcoidosis: May cause an isolated joint syndrome with swelling and pain in the joints of the fingers. The acute course resolves without consequences, while the rarer chronic course leads to deformations.

Etiology and types of osteoarthritis

The development of degenerative changes is associated with multiple factors. Joint structure is influenced by genetic predisposition, age, gender (the disease is more common among women), as well as race and diet.

• Primary osteoarthritis (Primary Osteoarthritis): A generalized process that occurs without an obvious cause and has a strong genetic basis. Hands are one of the most typical localizations for this form.
• Secondary osteoarthritis (Secondary Osteoarthritis): Develops against the background of an established primary cause that alters biomechanics or tissue structure. Such causes include trauma, endocrine pathologies (diabetes mellitus, hypothyroidism, acromegaly), storage diseases (hemochromatosis, Wilson's disease), and crystal-associated diseases (gout, pseudogout). Radiographically, secondary OA is completely identical to primary OA.

Radiological presentation

Radiographic changes in osteoarthritis reflect a combination of tissue destruction and repair processes. There are five basic signs (Radiographic Findings):

1. Joint space loss (Joint space loss): Indicates cartilage thinning. In OA, it is always asymmetrical in nature, as it occurs in areas of maximum load. This is an important distinguishing feature from other arthropathies.
2. Osteophytes (Osteophyte formation): Proliferations of new hypertrophied bone tissue at the margins of the joint or subchondrally.
3. Subchondral changes: Increased osteoblast activity causes subchondral sclerosis. Cysts may also form (due to synovial fluid penetration through cartilage defects) along with bone collapse.
4. Loose bodies: Detached fragments of bone and cartilage ("joint mice") that can persist within the cavity, become revascularized, and increase in size.
5. Deformity and subluxation: Occur as a consequence of ligamentous laxity, cartilage loss, and bone destruction. In elderly patients, the process is exacerbated by decreased muscle tone.

Class and exam questions

What else to study on this topic

• Pathogenesis of rheumatoid arthritis: from productive synovitis to ankylosis.
• Crystal-associated joint diseases: gout and pseudogout.
• Impact of systemic sclerosis on the musculoskeletal system and the development of contractures.
• Risk factors and genetic predisposition to primary osteoarthritis.
• Connective tissue quality abnormalities (Marfan and Ehlers-Danlos syndromes) as a cause of arthropathies.

Other topics in the "Additional Topics" section

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.