Cubital tunnel syndrome is a type of ulnar nerve compression neuropathy which can occur from a pathological compression of the ulnar nerve at the cubital tunnel.
It is the second most common peripheral neuropathy of the upper extremity 1,3.
Ulnar nerve compression can result in altered sensation in the little and ring fingers. In many patients, sensory loss is often the first symptom to be reported. As the condition progresses, they may be clumsiness in the hand, as the ulnar nerve is the principal motor supply to the intrinsic muscles of the hand. In well‐established cases, there may be marked wasting of the small muscles of the hand and the ulnar‐sided muscles of the forearm 4.
It can arise from varying causes which include:
- subluxation/dislocation of the ulnar nerve from congenital laxity in fibrous tissue
- extrinsic compression
- humeral fracture with loose bodies or callus formation
- osteophytic bony spur arising from the epicondyle or olecranon
- compression from an accessory muscle, namely anconeus epitrochlearis muscle
- soft-tissue mass/tumour
- synovitis secondary to rheumatoid arthritis
- infective process (e.g. tuberculosis)
- thickened cubital tunnel retinaculum (or arcuate ligament) of the flexor carpi ulnaris muscle
Exact imaging features may vary dependent on underlying cause. Thickening of the ulnar nerve can be a commonly observed feature.
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