Surgery chapters
Spinal trauma and peripheral nerve injuries
Assessment and early management of spinal and spinal cord injury (immobilisation, imaging, ASIA grading, cord syndromes, neurogenic and spinal shock, specific fractures), followed by the classification, assessment and repair of peripheral nerve injuries.
- Assume every major trauma patient has a spinal injury: restrict spinal movement, log-roll, image with CT, and use MRI for neurological deficit; steroids are not given.
- Neurogenic shock (injury at T6 or above) = hypotension with bradycardia and warm skin; spinal shock = temporary flaccid areflexia below the lesion that ends when the bulbocavernosus reflex returns.
- Nerve injuries: neurapraxia recovers fully, axonotmesis regrows at about 1 mm/day with an advancing Tinel sign, neurotmesis needs repair.
On this page
Overview
Spinal injury ranges from a stable bony injury to complete cord transection. Road traffic accidents are the leading cause worldwide, and young men are most often affected. Missed or mishandled injuries can turn a recoverable deficit into permanent paralysis.
Peripheral nerve injuries are often hidden behind the fractures and dislocations that cause them. Every limb injury needs a recorded nerve and vascular examination before and after any manipulation.
Spinal anatomy that matters
- The cord ends as the conus medullaris at about L1–L2 in adults (lower in infants). Below this lies the cauda equina (lower motor neurone roots).
- Lateral corticospinal tract: motor; crosses in the medulla.
- Dorsal columns: position, vibration, fine touch; cross in the medulla.
- Spinothalamic tracts: pain and temperature; cross within 1–2 segments of entry.
- Cervicothoracic (C7–T1) and thoracolumbar (T11–L2) junctions are where mobile segments meet rigid ones, so injuries cluster there. C5–C6 has the most flexion-extension; C5 is the commonest fractured cervical level in adults.
- Three-column model (anterior, middle, posterior): disruption of two or more columns = unstable.
Initial assessment
- ATLS primary survey takes priority. Restrict spinal movement (collar, blocks, flat position) in every major trauma patient until the spine is cleared.
- Log-roll with enough staff to inspect and palpate the whole spine (tenderness, steps, gaps, swelling) and to do a rectal examination (anal tone, voluntary contraction, perianal sensation).
- Spinal boards are only for transfer; they cause pressure sores quickly in insensate skin.
- Find one spinal injury → look for another: a second injury at a different level occurs in about 10%.
- Respiratory risk: injury at C3–C5 paralyses the diaphragm; lower cervical and upper thoracic injury paralyses the intercostals.
- Cord injury hides abdominal signs; image the abdomen in high-energy trauma.
Clinical clearance of the cervical spine
NEXUS low-risk criteria (all must be met to skip imaging): no midline cervical tenderness, no intoxication, normal alertness, no focal neurological deficit, no painful distracting injury. The Canadian C-spine rule is an alternative.
NEXUS: Neuro deficit, Ethanol/intoxication, eXtreme distracting injury, Unable to give history, Spinal tenderness.
Imaging
- CT is the gold standard for bony injury; scan the cervical spine with any head CT after significant injury.
- Plain films (lateral, AP, open-mouth odontoid) can miss about 15% of injuries; the C7–T1 junction must be seen. On the lateral film check prevertebral soft tissue, the three alignment lines (anterior, posterior vertebral and spinolaminar), and signs of instability (more than 3.5 mm translation or more than 11° angulation).
- MRI for any neurological deficit, suspected ligament or disc injury, or SCIWORA (spinal cord injury without radiographic abnormality, mainly in children).
- No flexion-extension films in the acute phase.
Types of shock in spinal injury
| Feature | Haemorrhagic (hypovolaemic) | Neurogenic shock | Spinal shock |
|---|---|---|---|
| Cause | Blood loss | Loss of sympathetic outflow (cord injury at T6 or above, mostly cervical) | Temporary "stunning" of cord function |
| Blood pressure | Low | Low | Not a circulatory state |
| Pulse | Fast | Normal or slow | – |
| Skin | Cold, clammy | Warm, pink | – |
| Neurology | – | – | Flaccid paralysis, areflexia, no tone below the level |
| Treatment | Stop bleeding, blood | Modest fluids, then vasopressors; atropine for bradycardia; avoid fluid overload | Supportive; lasts days to 6 weeks or more |
Spinal shock ends when the bulbocavernosus reflex returns (squeezing the glans or tugging the urinary catheter makes the anal sphincter contract). Only then can a cord injury be called complete; spasticity and brisk reflexes follow.
Hypotension in a trauma patient with a cord injury is still assumed to be haemorrhage first. Neurogenic shock is diagnosed only after bleeding is excluded.
Grading the cord injury
- Neurological level = the lowest segment with normal function on both sides (motor level: lowest key muscle of at least grade 3).
- Incomplete injury = any preserved function below the level, especially sacral sparing: perianal sensation, voluntary anal contraction, voluntary toe flexion. (Reflexes such as anal wink do not count.)
| ASIA (Frankel) grade | Meaning |
|---|---|
| A | Complete: no motor or sensory function in S4–S5 |
| B | Sensory present, motor absent below the level |
| C | Motor present but most key muscles below grade 3 (not useful) |
| D | Motor useful: most key muscles grade 3 or more |
| E | Normal |
Incomplete cord syndromes
| Syndrome | Mechanism | Features | Prognosis |
|---|---|---|---|
| Central cord | Hyperextension in an elderly patient with cervical spondylosis (fall onto the face) | Arms weaker than legs, hands worst; variable sensory loss; bladder involvement | Fairly good; legs recover first |
| Anterior cord | Flexion injury or anterior spinal artery ischaemia | Paraplegia and loss of pain and temperature; dorsal columns preserved (position, vibration) | Worst of the incomplete syndromes |
| Brown-Séquard (hemisection) | Penetrating (stab) injury | Same side: weakness and loss of position/vibration; opposite side: loss of pain and temperature 1–2 levels down | Best; most walk again |
| Posterior cord | Rare | Loss of proprioception; motor preserved | Good |
| Conus medullaris / cauda equina | Injury at T12–L2 or below | Saddle anaesthesia, bladder and bowel dysfunction, lower motor neurone leg weakness | Variable; roots recover better than cord |
Central cord = "Central = Carrying arms" (arm fibres lie centrally, so arms suffer most).
Specific spinal injuries
| Injury | Mechanism | Key facts | Treatment |
|---|---|---|---|
| Atlanto-occipital dislocation | Severe flexion-distraction | Usually fatal; cause of death in shaken infants | Halo or occipitocervical fusion |
| Jefferson fracture (C1 burst) | Axial load on top of the head (diving) | Best seen on open-mouth view and CT; cord usually spared; lateral masses spread; combined overhang > 6.9 mm suggests transverse ligament rupture | Collar or halo; fusion if unstable |
| Odontoid (dens) fracture | Flexion or extension | Type I tip; Type II base of the dens (commonest, high non-union); Type III extends into the C2 body | Collar or halo about 3 months; screw or C1–C2 fusion for displaced type II |
| Hangman's fracture | Hyperextension (judicial hanging, dashboard) | Bilateral fracture of the C2 pars interarticularis (traumatic spondylolisthesis of C2) | Rigid collar; surgery if displaced |
| Subaxial (C3–C7) | Flexion, compression, distraction, extension | Facet subluxation and bilateral locked facets cause severe cord injury | Skull tong traction to realign, then fixation |
| Wedge compression | Flexion with axial load | Anterior height loss; usually stable; osteoporotic fractures in the elderly | Brace; vertebroplasty or kyphoplasty if painful |
| Burst fracture | Axial compression | Comminuted body, widened interpedicular distance, retropulsed fragments into the canal | Unstable types: posterior fixation |
| Chance fracture | Flexion-distraction over a lap belt | Horizontal split through body and posterior elements at the thoracolumbar junction; linked with duodenal, pancreatic, mesenteric and aortic injuries | Usually fixation; look for abdominal injury |
- Ankylosing spondylitis: a fused, brittle spine fractures easily; do not force a collar on; keep in the position of comfort.
- Thoracic fracture-dislocations often cause complete deficits because the canal is narrow.
- Lumbar (below L2) injuries affect the cauda equina, so complete deficits are less likely.
Management of spinal cord injury
- Prevent secondary injury: avoid hypoxia and hypotension; keep the spine aligned.
- Realign cervical dislocations with skull tong traction; halo vest for some fractures.
- Surgery (decompression and stabilisation) for unstable injuries and persisting compression. The only absolute indication is worsening neurology.
- Corticosteroids (methylprednisolone) are no longer recommended in acute traumatic cord injury (steroids still help non-traumatic malignant cord compression).
- Bladder: catheter; later intermittent self-catheterisation.
- Early transfer to a spinal injuries centre.
Later complications
- Pressure sores: turn regularly; pressure-relieving mattress.
- DVT (about 30%) and PE: stockings and low molecular weight heparin.
- Autonomic dysreflexia (injury above about T6): a full bladder or loaded rectum triggers severe hypertension, bradycardia, headache, flushing and sweating above the level. Sit up, empty the bladder (check the catheter), clear the rectum, give a fast-acting antihypertensive if needed.
- Spasticity (baclofen), neuropathic pain, post-traumatic syringomyelia (rising level of sensory loss, pain, weakness years later), heterotopic ossification, osteoporosis and fractures, contractures, depression.
Function by level (cervical injuries)
| Level | Expected function |
|---|---|
| C3–C4 | May be ventilator dependent; mouth/chin-controlled wheelchair |
| C5 | Elbow flexion; powered wheelchair; feeds with aids |
| C6 | Wrist extension; may push a manual chair, drive an adapted car |
| C7 | Elbow extension; independent transfers with a manual wheelchair |
| C8–T4 | Hand function; independent in most daily activities |
| Lumbar | May walk with braces |
Peripheral nerve injuries
Seddon and Sunderland classification
| Seddon | Sunderland | What is damaged | Tinel sign | Recovery |
|---|---|---|---|---|
| Neurapraxia | 1st degree | Segmental demyelination; axon intact; conduction block | Negative | Full, in days to weeks |
| Axonotmesis | 2nd degree (3rd and 4th are worse grades in between) | Axon cut, endoneurial tubes intact; Wallerian degeneration distally | Positive, advances about 1 mm/day | Good, spontaneous (worse as more layers are torn) |
| Neurotmesis | 5th degree | Whole nerve divided (or only epineurium left in 4th degree) | Stays at the injury; neuroma | None without repair; never perfect |
- Neurapraxia examples: crutch palsy, "Saturday night palsy" (radial nerve pressure while drunk), mild tourniquet palsy.
- Wallerian degeneration: the axon and myelin distal to the cut break down within days; Schwann cells multiply and guide regrowth.
- Regeneration about 1 mm per day (1–2 mm in Apley). Motor end-plates and sensory receptors that are not reinnervated within about 18–24 months are lost for good.
- EMG: denervation potentials appear by about 3 weeks; their presence rules out neurapraxia but cannot separate axonotmesis from neurotmesis.
Tinel's sign (tingling in the nerve's territory on tapping over it) marks the front of regenerating axons. If it advances, the nerve is recovering; if it stays put, suspect neurotmesis and explore.
Assessment and treatment
- Examine motor power (MRC grade 0–5), sensation, sweating (dry skin in the nerve territory) and look for an associated arterial injury.
- Closed, low-energy injury (most neurapraxia/axonotmesis): observe, splint, keep joints moving, protect numb skin; explore if recovery does not appear on time.
- Explore early if the nerve is seen to be divided, after open/sharp injuries, or after high-energy injuries likely to have divided it.
- New palsy after manipulation or fixation of a fracture: likely iatrogenic, so explore.
A radial nerve palsy present on arrival with a closed humeral shaft fracture is usually observed (most recover), but a palsy that appears after reduction or fixation, or occurs with an open fracture, needs exploration.
- Primary repair (best results): clean ends, correct orientation, fine epineurial sutures, no tension; splint for about 3 weeks.
- Nerve graft (usually the sural nerve) when ends cannot meet without tension; nerve transfer for root avulsions; tendon transfers when the muscle can no longer be reinnervated.
- Better prognosis: young patient, early repair, distal (low) lesion, purely motor or purely sensory nerve, clean cut, short gap.
Common nerve injuries
| Nerve | Typical cause | Main deficit |
|---|---|---|
| Axillary (C5, C6) | Shoulder dislocation, surgical neck of humerus fracture | Weak abduction (deltoid); numb patch over the deltoid ("regimental badge" area) |
| Radial | Midshaft humerus fracture (spiral groove); Saturday night palsy | Wrist drop, can't extend fingers; small numb patch on the dorsum of the first web space. Posterior interosseous lesion: finger drop without wrist drop or sensory loss |
| Ulnar | Medial epicondyle fracture, elbow dislocation, wrist cuts | Claw hand of ring and little fingers, wasted interossei, Froment's sign; high lesions claw less ("ulnar paradox") |
| Median | Supracondylar fracture (anterior interosseous branch), wrist cuts | Low: thenar wasting, cannot abduct/oppose thumb, numb radial 3½ digits; high: "pointing index" (benediction posture when making a fist) |
| Common peroneal | Fibular neck fracture, tight plaster, lateral knee injury | Foot drop, high-stepping gait, numb dorsum of foot |
| Sciatic | Posterior hip dislocation, hip replacement | Foot drop (peroneal division most vulnerable), loss of hamstrings and all below-knee muscles |
| Long thoracic | Axillary surgery, carrying loads | Winging of the scapula (serratus anterior) |
| Accessory | Posterior triangle lymph node biopsy | Drooping shoulder, weak shrug (trapezius) |
Brachial plexus injury
- Mostly motorcycle accidents (traction between neck and shoulder) or birth injury.
- Preganglionic (root avulsion): cannot recover or be repaired directly. Clues: Horner's syndrome (T1), burning pain in a numb hand, paralysis of scapular muscles or the diaphragm, cervical spine fracture, preserved sensory nerve conduction and a positive histamine flare in numb skin.
- Postganglionic: may recover or be repaired/grafted; explore early (results are poor after about 6 months).
| Palsy | Roots | Cause | Posture |
|---|---|---|---|
| Erb's | C5, C6 (± C7) | Shoulder dystocia in large babies; fall onto the shoulder | Arm adducted, internally rotated, elbow extended, forearm pronated: "waiter's tip" |
| Klumpke's | C8, T1 | Breech delivery, arm pulled upwards | Claw hand, wasted small hand muscles; Horner's if T1 avulsed |
In obstetric palsy, return of biceps activity by about 3 months predicts a good outcome; no biceps by then is an indication to consider surgery.
Expect: neurogenic versus spinal versus haemorrhagic shock, bulbocavernosus reflex marking the end of spinal shock, sacral sparing meaning incomplete injury, central, anterior and Brown-Séquard syndromes and their prognosis, NEXUS criteria, CT as the standard and MRI for deficits, steroids no longer used, Jefferson, odontoid type II, hangman's and Chance fractures, autonomic dysreflexia, Seddon grades with Tinel's sign, regeneration at about 1 mm a day, and the classic nerve-fracture pairs (axillary-shoulder dislocation, radial-humeral shaft, ulnar-medial epicondyle, median-supracondylar, peroneal-fibular neck, sciatic-posterior hip dislocation), plus Erb's and Klumpke's palsies and signs of root avulsion.
Quick revision
- Immobilise, log-roll, CT; MRI for deficits; image the whole spine (10% second injury).
- Neurogenic shock: low BP + slow pulse + warm skin; vasopressors.
- Spinal shock: flaccid areflexia; ends with bulbocavernosus reflex.
- Incomplete = sacral sparing. ASIA A complete to E normal.
- Central cord (elderly, arms), anterior cord (worst, dorsal columns spared), Brown-Séquard (best, crossed signs).
- Jefferson C1 axial load; hangman's C2 extension; odontoid type II commonest; Chance = lap belt + bowel injury.
- No steroids in traumatic cord injury.
- Neurapraxia (full recovery), axonotmesis (1 mm/day, Tinel advances), neurotmesis (repair).
- Erb's C5–6 waiter's tip; Klumpke's C8–T1 claw hand and Horner's.
Written by The House Job from standard references (Bailey & Love; ATLS Student Course Manual; Apley's System of Orthopaedics and Fractures).
FAQ
How can neurogenic shock be told apart from haemorrhagic shock?
Neurogenic shock gives low blood pressure with a normal or slow pulse and warm skin, while haemorrhagic shock gives a fast pulse and cold, clammy skin.
When can a spinal cord injury be called complete?
Only after spinal shock has ended (bulbocavernosus reflex back) and there is still no motor or sensory function in the lowest sacral segments.
Why are steroids no longer given for acute spinal cord injury?
Studies have not shown a convincing benefit, while they add infection and other complications.
What does an advancing Tinel sign mean?
The regenerating axons are growing down the nerve sheath, so the injury is in continuity and recovery is under way.
Which nerve is at risk in a midshaft fracture of the humerus?
The radial nerve in the spiral groove, causing wrist drop; most such palsies are neurapraxia or axonotmesis and recover.