Execution
- 1Position the patient sitting with the forearm supported.
- 2Hold the patient’s hand and wrist and observe the midcarpal region during radial and ulnar deviation.
- 3Move the wrist from radial deviation toward ulnar deviation while monitoring the proximal carpal row.
- 4Note whether a catch-up clunk or painful snap occurs as the wrist reaches ulnar deviation.
- 5Compare with the opposite wrist and check whether symptoms match the patient’s complaint.
Positive outcome
A painful or symptomatic catch-up clunk during ulnar deviation is positive. Magee describes midcarpal instability as the proximal carpal row staying flexed too long and then snapping into dorsiflexion. A painless clunk may occur in some hypermobile wrists and should not be overinterpreted.
Studies
| Study | Reliability | Sn | Sp | LR+ | LR− |
|---|---|---|---|---|---|
| Lichtman et al. — year unverified | NA | NA | NA | NA | NA |
| Niacaris et al. (2015) — review | NA | NA | NA | NA | NA |
CommentMagee discusses midcarpal instability as a motion-pattern problem, often apparent during ulnar deviation. This is not a high-quality diagnostic-accuracy test. Use it to decide whether more detailed carpal instability assessment or imaging referral is needed.
Low Clinical Value