Humeral-shaft fracture and radial-nerve injury — Rapid

Synopsis

Stabilise humeral-shaft fracture, document radial and wider neurovascular function accurately, distinguish primary from new iatrogenic palsy, and select functional bracing, fixation or nerve exploration safely.

Inspect the whole arm for wounds, deformity and skin pressure and examine shoulder and elbow because associated joint injury changes care.
Before and after splintage, test wrist extension, finger MCP extension, thumb extension, dorsal first-web sensation, median and ulnar functions, pulses and refill.
Obtain AP and lateral radiographs of the full humerus including shoulder and elbow; pathological features may require staging before definitive fixation.
A closed primary radial palsy is commonly observed with fracture treatment and serial recovery assessment rather than explored automatically.
Open fracture, vascular injury, penetrating laceration, irreducible entrapment or a new post-manipulation palsy lowers the threshold for urgent exploration.
Many closed suitable fractures use initial splintage followed by a functional brace, with early shoulder and elbow movement and alignment review.
Operative fixation is considered for open, vascular, pathological, polytrauma, segmental, failed closed or functionally unacceptable patterns.
Provide a wrist-extension splint and hand therapy for radial palsy to preserve grasp, joint position and passive range during nerve recovery.

Key red flags

A cool hand, absent pulse, expanding arm haematoma or recurrent bleeding requires immediate realignment and combined vascular and orthopaedic assessment.

A wound near the shaft, penetrating mechanism or exposed bone triggers the open long-bone pathway and early antibiotic prophylaxis.

A radial deficit first appearing after reduction, splintage or fixation requires urgent reassessment for entrapment, compression or iatrogenic injury.

Shaft fracture

Arm pain, swelling, shortening, angulation and crepitus follow direct or torsional trauma.

Radial palsy

Wrist, finger and thumb extension weakness with dorsal first-web sensory change produces wrist drop.

Secondary palsy

A new deficit after manipulation, brace fitting or fixation raises concern for compression, entrapment or iatrogenic injury.

Arterial injury

Pulse loss, coolness, delayed refill or expanding swelling requires immediate limb-saving coordination.

Investigation priorities

Full-length AP and lateral humeral radiographsFirst step

Define fracture and include both shoulder and elbow joints.

Management branches

First assessmentAlign and map nerve function

A humeral-shaft fracture is suspected after trauma.

Use ABCDE for high energy, expose wounds and inspect shoulder, arm and elbow.
Give analgesia and document pulses and radial, median and ulnar motor and sensory findings.
Obtain full-length films, align and splint and repeat the identical examination.

Key medicines

Paracetamol for adult arm-fracture painFor an adult, prescribe 500 mg to 1 g orally as required, with a minimum 4-hour interval and a maximum of four administrations in one day.Reduce the limit in low body weight or hepatic risk and count all combination products.

Intravenous prophylaxis for an open humerusGive the locally approved intravenous open-fracture agent and dose as soon as possible and within 1 hour, adjusted for allergy, renal function and contamination.Do not delay for imaging or cultures, and do not use continued antibiotics to compensate for inadequate excision.

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