|
Year |
2001 |
|---|---|
|
Question Number |
240. |
|
Category |
Select |
Question
The degree of ulnar variance is best defined by
1- arthrography
2- MRI
3- Cineradiographs
4- Stress radiographs
5- Plain radiographs
Figures
Answer (click for answer)
Preferred response: 5
Ulnar variance is the roentgenographic distance between contiguous articular surfaces of the distal radiocarpal and ulnocarpal joints. Ulnar variance is "negative" for an ulna which is shorter, or more proximal, than the radius. This distance changes with wrist and forearm position. Supination increases and pronation decreases the measurement of negative ulnar variance. Wrist deviation and grip also changes the measurement. Therefore, ulnar variance should be measured with plain, static, non-stressed radiographs. MRI and arthrography are not for bones.
Reference: Nagle DJ: Evaluation of chronic wrist pain. J Am Acad Orthop Surg 2000;8:45-55.
Epner RA, Bowers WH, Guilford WB: Ulnar variance: The effect of wrist positioning and roentegen filming technique. J Hand Surg Am 1982;7:298-305.