Osteoarthritis of the hand
Osteoarthritis of the hand is highly prevalent with the hand being the most common site of osteoarthritis (OA). It can be highly disabling, with severe cases comparable to rheumatoid arthritis in terms of disability. This article is focused on primary (idiopathic) osteoarthritis.
Terminology
The European League Against Rheumatism (EULAR) uses the following terms :
- nodal OA: interphalangeal joint OA with Heberden and/or Bouchard nodes
- non-nodal OA: interphalangeal joint OA without Heberden or Bouchard nodes
- thumb base OA: first carpometacarpal joint OA +/ scaphotrapeziotrapezoidal (STT) joint OA
- erosive OA: considered a subset of hand OA
Epidemiology
Hand osteoarthritis is highly prevalent with women over the age of 50 most commonly affected. The prevalence on hand radiographs is estimated at ~50% (range 27-80%), although many of these may be asymptomatic with prevalence rates of symptomatic hand OA reported at ~15% (range 6-26%) with increased prevalence in older age groups .
Risk factors
Major risk factors hand osteoarthritis includes :
- age >40 years
- female sex
- positive family history
- occupation (e.g. cotton picking, heavy manual labor, repetitive hand use)
- obesity
- prior joint injury
Pathology
Distribution
The sites of symptomatic hand OA (from most to least common) are :
- distal interphalangeal joints
- first carpometacarpal joint (thumb base)
- proximal interphalangeal joints
- metacarpophalangeal joints
Classification
Radiographics features
For a general discussion, please refer to the main article: Osteoarthritis. However, the joint space narrowing in hand OA may be symmetric compared with other joints where it is typically asymmetric .
Plain radiographs are considered the gold standard for imaging hand OA . Radiologically, OA of the hand is typically symmetrical and can be grouped in a variety of ways :
- clustering by row (more common for finger OA)
- clustering by ray (more common for thumb OA, where it may be isolated)
Osteophytes that develop in hand OA have eponymous names:
- Heberden nodes affect the DIP joint
- Bouchard nodes affect the PIP joint
Practical points
- symptomatic hand OA more commonly occurs when symmetrical and grouped by row rather than by ray