Wrist Drop

Excerpt

Wrist drop is a disabling clinical condition resulting from dysfunction of the radial nerve, a major peripheral nerve that provides motor innervation to the extensor muscles of the wrist and fingers and sensory innervation to the dorsum of the hand. The extensor mechanism plays a critical role in hand positioning during grasp and functional activities. Therefore, radial nerve palsy results in substantial impairment of hand function.

Radial nerve injury causes loss of wrist and digital extension, producing the characteristic posture of a flaccid, flexed hand when the forearm is held horizontally. Etiologies encompass traumatic causes such as humeral shaft fractures and penetrating injuries, as well as nontraumatic causes, including prolonged external compression (eg, Saturday night palsy). Systemic and metabolic disorders, such as lead toxicity and vasculitic neuropathies, also contribute to radial nerve dysfunction. Management is guided by the underlying etiology and severity of nerve injury. Treatment ranges from conservative measures, such as splinting, rehabilitation, and pharmacologic therapy, to surgical interventions, including nerve exploration, repair, or tendon transfer for severe or persistent deficits.