Test yourself: X-hand
Case Study 1
A 32-year-old man spent the evening out drinking and hit someone with his right fist. His right thumb is now very painful. Physical examination reveals pain on palpation at the level of the base of dig-I.
Active abduction and flexion of the thumb are possible but very painful.
A dig-I x-ray is made of the right hand (fig. 1).
Figure 1. Lateral image and AP image of dig-I in the right hand.
Neither images reveal obvious soft tissue swelling.
A cortex interruption can be seen in the lateral image at the ulnar side of the base of MC-I. The fracture line continues up to the CMC-I joint. There is minimal dislocation.
Note that the cortex interruption/fracture line is not clearly visible on the AP image.
♦ Figure 1. Answer: Bennett fracture.
Case Study 2
A 42-year-old woman ran into another cyclist and fell on the pavement. Especially her right hand is very painful.
Physical examination reveals a swelling at the level of MC-IV and MC-V. There is obvious axis pressure pain in metacarpal IV & V.
An x-ray of the right hand is made (fig. 2).
Figure 2. PA image (a) and oblique image (b) of the right hand.
Note an interruption of the zigzag configuration at the level of MC-IV and MC-V. The base of MC-IV and MC-V are not sharply delineated (particularly visible in the PA image). There are several cortex interruptions and lucencies, continuing up to the joint surface of the MCP joints.
The fractures are less clearly visible on the oblique image.
Comminuted intra-articular fracture of the base of MC-IV and MC-V.
♦ Figure 2. Answer: comminuted intra-articular fracture of the base of MC-IV and MC-V. See also the coronal CT reconstruction (c).