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OrthoVellum

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Hand & Upper Limb
intermediate
X-Type

Posterior Interosseous Nerve Syndrome

Nerve Compression Syndromes

A 50-year-old woman presents with progressive inability to extend her fingers at the MCP joints for 3 months. She reports no pain and has no sensory symptoms. Examination reveals weakness of finger MCP extension (EDC, EIP, EDM) and thumb extension/abduction (EPL, EPB, APL), but wrist extension is preserved with radial deviation (ECRL/ECRB intact). Sensation is intact throughout. EMG confirms denervation of PIN-innervated muscles. Regarding posterior interosseous nerve (PIN) syndrome:

Mark each as TRUE or FALSE

A

The posterior interosseous nerve (PIN) is the deep motor branch of the radial nerve that arises at t...

B

Sites of PIN compression include the arcade of Frohse (most common, present in 30% as fibrous band),...

C

PIN syndrome is primarily a sensory condition; the arcade of Frohse is distal to the supinator; PIN ...

D

Clinical findings: weakness of finger MCP extension (EDC, EIP, EDM), weakness of thumb extension/abd...

E

Treatment: non-operative management (splinting, activity modification, therapy) for 3 months initial...

Answer the questions to see explanations

Click T (True) or F (False) for each option