First Carpometacarpal Joint Osteoarthritis

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The first CMCJ is highly mobile which is probably linked to an increased rate of degeneration. There is also an association with hypermobility


Increases with age, most common in postmenopausal women. The female to male ratio is 6:1.1


  • Base of thumb pain
  • Activity related particularly gripping, using taps and door knobs, unscrewing lids, turning keys, sewing.
  • Thumb weakness
  • Deformity at the base of the first MCPJ.
  • Adduction of the 1st metacarpal may occur which is visualised by a reduced 1st web space and hyperextension of MCPJ.
  • Palpate for tenderness, crepitation, and subluxation
  • Range of motion
  • Power, pincer strength may be reduced
  • Grind test: Hold the 1st metacarpal, move the thumb in a circular motion, and apply axial compression

Differential Diagnoses

  • Scaphoid fracture (missed)
  • Non-union of scaphoid fracture
  • De Quervain Tendinopathy
  • Scaphoid impaction syndrome
  • Intersection Syndrome
  • Flexor carpi radialis tendinopathy
  • Dorsal pole of lunate impingement on distal radius (gymnasts)
  • Scapholunate dissociation
  • Osteoarthritis of the trapeziometacarpal (TMC) joint
  • Ganglia
  • Radial sensory nerve entrapment in the forearm
  • Crystal-induced arthritis
  • C6 radicular syndrome


Xray Inflammatory and rheumatological blood tests if required.


Activity Modification
Hand Therapy
Steroid Injection


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