Carpometacarpal osteoarthritis of the thumb

5 Surgical treatment for osteoarthritis of the thumb is indicated for severe disease (defined by radiographic evidence and pain that persists despite conservative therapy). 2 The carpometacarpal joint of the thumb is the most common site in the hand for which surgery is sought.1 Although most patients report a high degree of relief postoperatively, thumb strength is expected to decrease from preoperative values.5 Function is restored primarily through pain-free use of the thumb. 2 Anterior-posterior, lateral and oblique radiographic views of the thumb aid in confirming the diagnosis.1 Findings consistent with osteoarthritis include narrowing of the joint space and osteophytes, in addition to subchondral sclerosis and cysts, which can be used to stage disease using the Eaton and Littler classification. 2 In late-stage disease, radiographs show degenerative changes in the scaphotrapezial joint and a "zigzag" deformity (Appendix 1, available at www .cmaj .ca /lookup /suppl /doi:10.1503/cmaj.111444/-/DC1).1,2 The grind test (axial loading and rotation of the thumb) is a provocative manoeuvre used to test for the condition. Although a positive result is highly suggestive of disease (specificity 80%-93%), a negative result does not rule it out (sensitivity 42%-53%).3