A 5-year-old boy presents to the Accident Clinic with a fracture in the shaft of humerus. Then how will you exclude the involvement of radial nerve?

(B) Inability in extension of wrist and loss of sensation in area over anatomical snuff box# Most common form is radial nerve injuries associated with humeral fractures.> Most common injury resulting from dislocations or fracture-dislocation of the elbow seems to be ulnar nerve neurapraxia, which spontaneously resolves after a closed reduction.> Radial nerve palsy after fracture of the humerus is the most common nerve lesion in long bone fractures.> Average incidence of radial nerve lesions is approximately 11%. Most reported series of radial nerve lesions are associated with fractures of the middle third of the humerus.> Formed by: Axons from C5 to T1 roots> Axons pass through Spiral groove of humerus Fibrous arch attachment of triceps to humerus Lateral intermuscular septum below deltoid insertion Arcade ofFrohse: Above supinator & Below elbow> Branches: Above elbow1. Above spiral groove (Humerus) Triceps: 3 to 5 branches Anconeus2. Below spiral groove Brachioradialis: Distal to lateral intermuscular septum Extensor carpi radialis longus & brevis Posterior cutaneous nerves of arm & forearm - Supply lateral & dorsolateral arm & forearm - At or below elbow> Above arcade of Frohse (Supinator) Superficial radial nerve: Sensory dorsolateral hand & 1 st 3 digits Posterior interosseus nerve - Extensor carpi radialis brevis & Supinator - Passes through arcade of Frohse Posterior interosseus nerve - Terminal motor branch Passes through the supinator muscle> Innervates Finger & thumb extensors Extensor carpi ulnaris Abductor pollicis longus Articular branches to wrist joint> Wrist drop is the classical sign of radial nerve injury