From trauma to fibrosis: a case of ulnar nerve entrapment in Guyon’s canal

Guyon's canal syndrome is an uncommon distal ulnar neuropathy caused by compression within the wrist. We report a case of delayed ulnar nerve entrapment secondary to post-traumatic fibrosis, diagnosed nine years after wrist injury and surgery. High-resolution ultrasonography demonstrated focal nerve compression within Guyon's canal adjacent to fibrotic tissue. The patient presented with chronic sensory deficits and hypothenar atrophy. Conservative treatment led to partial symptom control. This case highlights delayed post-surgical fibrosis as a potential cause of Guyon's canal syndrome and underscores the diagnostic value of ultrasound in chronic compressive neuropathies.