Slideshow
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Figure 1. Anteroposterior radiograph of the right hand.
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Figure 2. Oblique view of the right hand.
A 64-year-old woman presents with thumb pain for >6 months, and severe arthritis of the right carpometacarpal (CMC) joint is diagnosed. Splinting, ice, oral anti-inflammatory agents, and intra-articular injections do not provide long-term relief of her symptoms. Anteroposterior and oblique radiographs of the right hand are obtained (Figures 1 and 2).
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The base of the thumb, or basilar thumb, is one of the most common locations for osteoarthritis in the hand. The first CMC joint joins the first metacarpal base and the trapezium, the saddle-shaped wrist bone. An easy way to remember that the trapezium is part of the CMC joint is to think “trapezi-thumb.”
Chronic instability is thought to be the most common cause of CMC arthritis, a condition that is more common in women than men. Joint laxity increases stress loads on the CMC joint, causing cartilage loss, bony impingement, and pain.1 The hormonal theory suggests that increased relaxin and estrogen in women contributes to the joint instability.2
The typical presentation of CMC joint arthritis includes patients aged >50 years with pain and crepitus over the joint. A thumb CMC grind test, or performing axial compression with rotation of the metacarpal, is a specific provocative test.
When conservative treatment with splinting, ice, oral anti-inflammatory agents, and intra-articular injections is unsuccessful, surgery may be considered. LRTI is the most common surgical procedure performed for CMC joint arthritis in the United States.3 LRTI includes removal of the trapezium and inserting a rolled tendon graft, such as the palmaris longus or abductor pollicis longus. The tendon acts as a cushion on the metacarpal base, which helps relieve pain associated with arthritis.3,4
Dagan Cloutier, MPAS, PA-C, practices in a multispecialty orthopedic group in the southern New Hampshire region and is editor-in-chief of the Journal of Orthopedics for Physician Assistants (JOPA).
References
1. Gillis J, Calder K, Williams J. Review of thumb carpometacarpal arthritis classification, treatment and outcomes. Can J Plast Surg. 2011;19(4):134-138.
2. Wolf JM, Scher DL, Etchill EW, et al. Relationship of relaxin hormone and thumb carpometacarpal joint arthritis. Clin Orthop Relat Res. 2014;472(4):1130-1137.
3. Calfee R. Thumb carpometacarpal osteoarthritis. JBJS website. https://www.jbjs.org/summary.php?id=270. Published May 7, 2019. Accessed December 10, 2019.
4. Gottschalk MB, Patel NN, Boden AL, Kakar S. Treatment of basilar thumb arthritis: a critical analysis review. JBJS Rev. 2018;6(7):e4.
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