Clinical History:
M60 with 2 months ache along the dorsolateral aspect of proximal forearm after 'taking up weights’.
Imaging:
Diagnosis:
Posterior interosseous nerve entrapment at the distal end of supinator tunnel
Discussion:
A long-axis image of posterior interosseous nerve is shown at the level of distal exit from supinator tunnel. On real-time examination, there was localised tenderness (or 'trigger point' producing symptoms) directly over the distal exit point of posterior interosseous nerve from supinator tunnel where the nerve showed a 5mm long segment of fusiform swelling consistent with entrapment 'neuroma' (arrowheads). Arrow indicates the nerve within the distal portion of supinator tunnel (heads of supinator muscle shown by asterisks).
NOTE: PIN = posterior interosseous nerve
