Orthopaedic Surgery - Burners (Stingers)

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Basics

A burner or stinger is a transient neurologic injury most commonly seen in athletes participating in contact or collision sports.

The injury usually involves compression, traction, or a combination of both affecting the upper trunk of the brachial plexus, particularly the C5 and C6 nerve roots.

Patients typically experience a sudden burning or electric pain radiating from the neck or shoulder into the arm, sometimes accompanied by numbness, tingling, or weakness.

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Mechanism of Compression

Compression can occur when the athlete’s head is forcibly turned or bent toward the injured side.

This narrows the neural foramina and may compress the cervical nerve roots or upper brachial plexus.

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Mechanism of Traction

Traction injury occurs when the shoulder and arm are forced downward while the neck bends or rotates toward the opposite side.

This stretches the upper portion of the brachial plexus and may transiently impair nerve conduction.

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Direct-Blow Mechanism

A direct impact over Erb point, located approximately 2–3 cm above the clavicle where the C5 and C6 nerve roots converge, can also produce a stinger.

This mechanism can directly compress or contuse the upper trunk of the brachial plexus.

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Age-Related Pattern

Burners are more commonly encountered in younger athletes.

Older athletes experiencing a similar mechanism are more likely to have a cervical nerve root injury because degenerative changes and cervical stenosis become more common with age.

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Classification

Stingers can be classified according to the severity of nerve injury.

Grade I represents a neurapraxia, in which nerve conduction is temporarily impaired without permanent structural disruption. Symptoms are generally short-lived and there may be no persistent motor or sensory deficit.

Grade II represents axonotmesis, with disruption of axons but preservation of some supporting nerve structures. Motor weakness is usually present and sensory symptoms may also occur.

Grade III represents neurotmesis, the most severe form, with major disruption of the nerve. Motor or sensory deficits may persist for longer than a year.

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General Prevention

The only complete method of prevention is avoidance of activities involving significant contact or collision.

For athletes who continue participating, prevention should focus on appropriate equipment, correct technique, and conditioning.

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Protective Equipment

In American football, neck collars or similar protective devices may reduce excessive cervical motion and may help decrease the likelihood of recurrent stingers in selected athletes.

Helmets and shoulder pads should be checked to ensure proper fit.

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Sports Technique

Proper tackling and blocking technique is important.

Athletes should avoid leading with the head or placing the cervical spine in positions that produce excessive lateral bending or extension.

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Strengthening

Strengthening the neck, shoulder girdle, and scapular stabilizing muscles may reduce recurrence.

Improved muscular control can help limit excessive neck and shoulder displacement during contact.

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Epidemiology

Burners occur predominantly in young male athletes involved in contact sports, particularly American football and rugby.

Recurrence is common.

Recent studies suggest that approximately one-fifth to one-third of stinger episodes may represent recurrent injuries.

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Incidence

In collegiate American football, an incidence of approximately 2.04 injuries per 10,000 athlete exposures has been reported.

In one rugby cohort, approximately 21% of players experienced a stinger, with a reinjury rate of approximately 37% during the same season.

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Risk Factors

A previous history of a stinger is the strongest predictor of a future episode.

Cervical spinal or foraminal stenosis is another important risk factor because it reduces the space available for the cervical nerve roots.

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Genetics

No specific genetic association has been identified.

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Etiology

Most burners result from compression, traction, or combined compression and traction of the upper brachial plexus.

In American football, the majority occur during tackling or blocking.

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Associated Conditions

Recent evidence suggests an association between recurrent stingers and scapular dyskinesis, particularly in rugby athletes.

Abnormal scapular mechanics may alter shoulder and cervical positioning during contact and increase neural stress.

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Diagnosis

Signs and Symptoms

The classic symptom is an immediate sharp, burning, or electric pain radiating from the shoulder or neck down one arm.

Paresthesias, numbness, or weakness may accompany the pain.

Symptoms usually resolve within several minutes, although some athletes experience weakness or sensory disturbance lasting much longer.

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Delayed Weakness

Strength may initially appear normal immediately after injury.

However, weakness can occasionally develop or become more noticeable over the following hours or days.

For this reason, serial neurologic examination is important.

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Physical Examination

The examination should begin with assessment of the cervical spine and affected upper extremity.

If the athlete has no neck pain or tenderness, cervical range of motion may be evaluated carefully.

A simple stinger usually allows full and painless cervical motion.

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Palpation

There is often no significant tenderness over the cervical spine, clavicle, or shoulder.

Tenderness over these areas should raise suspicion for an associated fracture, dislocation, or structural injury.

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Neurologic Examination

Motor strength and sensation should be compared with the contralateral side.

Transient weakness most commonly follows a C5–C6 distribution.

Affected muscles may include the deltoid, biceps, and shoulder external rotators.

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Spurling Test

The Spurling test may reproduce symptoms when cervical nerve root compression contributes to the injury.

The neck is placed into extension, rotation, and lateral bending toward the symptomatic side, followed by gentle axial compression.

Reproduction of radiating symptoms into the ipsilateral arm is considered a positive test.

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Bilateral Symptoms

Bilateral arm symptoms are not typical of a simple stinger and should raise concern for a cervical spinal cord or major cervical spine injury.

If both arms are involved, the athlete should be treated as having a potentially unstable cervical spine injury.

The neck should be immobilized, and protective equipment should generally remain in place until appropriate transport and evaluation can be completed.

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Imaging

Indications for Cervical Radiographs

Routine imaging is not necessary after every uncomplicated first-time stinger that resolves rapidly.

Cervical radiographs should be considered when the patient has recurrent episodes, neck pain, stiffness, tenderness, or pain with cervical range of motion.

Radiographs can help identify fracture, alignment abnormalities, or cervical stenosis.

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MRI

MRI of the cervical spine is particularly important when symptoms are bilateral, persistent, recurrent, or associated with abnormal neurologic findings.

It can evaluate for cervical stenosis, disc herniation, nerve root compression, or spinal cord pathology.

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Pathological Testing

Histologic or other pathological testing is not routinely required for the diagnosis.

Burners are diagnosed primarily through clinical history, physical examination, and selective imaging or electrodiagnostic testing.

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Differential Diagnosis

Important differential diagnoses include cervical spine fracture, cervical disc herniation, clavicle fracture, shoulder fracture or dislocation, and soft-tissue injuries of the shoulder.

Because these conditions can mimic or accompany a stinger, careful examination is essential before return to play.

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Treatment

Initial Management

The athlete should be removed immediately from play after a stinger.

Return should not be permitted while pain, paresthesias, weakness, sensory loss, or restricted motion remains.

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Return-to-Play Criteria

Accepted criteria for return include full and painless cervical and shoulder range of motion, complete resolution of paresthesias, normal sensation, and full strength.

The athlete should also be able to participate in practice without recurrent symptoms before returning to unrestricted competition.

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Same-Day Return to Play

A player may return during the same event only when symptoms have completely resolved and the examination is normal.

There should be no pain at rest or during provocative testing, and strength and sensation must be equivalent to the opposite side.

Any residual neurologic abnormality is a contraindication to immediate return.

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Persistent Neurologic Deficit

Athletes with incomplete neurologic recovery should undergo repeated examinations.

They should not return to contact sport until strength, sensation, and range of motion have fully normalized.

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Recurrent Stingers

Athletes with repeated episodes should not return to play until an appropriate cervical spine evaluation has been completed.

Imaging should exclude structural conditions such as stenosis or disc herniation that could increase the risk of further neurologic injury.

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Cervical Foraminal Stenosis

Athletes with significant cervical foraminal or spinal canal stenosis require particularly careful counseling.

When clinically significant stenosis is present, avoidance of contact and collision sports may be recommended because of the risk of recurrent or more serious neurologic injury.

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Electromyography and Return to Sport

An abnormal electromyographic study does not automatically prohibit return to sport.

Return-to-play decisions should be individualized according to symptoms, strength, neurologic examination, imaging, and the pattern of electrodiagnostic abnormalities.

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Physical Therapy

Physical therapy can improve neck and shoulder range of motion, flexibility, strength, and neuromuscular control.

Rehabilitation commonly emphasizes cervical strengthening, shoulder girdle conditioning, posture, and scapular stabilization.

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First-Line Management

The athlete should remain out of competition until all symptoms have resolved.

Serial neurologic examinations should document recovery of motor function, sensation, reflexes, and cervical motion.

Athletes with recurring symptoms should undergo imaging before returning to play.

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Electromyography

Electromyography is generally considered when weakness, numbness, or other neurologic symptoms persist beyond approximately 3 weeks.

It can help determine the severity and location of nerve injury and identify evidence of axonal loss.

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Further Imaging After EMG

MRI should be considered when electromyography is abnormal or when symptoms involve both upper extremities.

MRI can identify cervical spinal stenosis, disc disease, or another structural cause of persistent neurologic dysfunction.

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Follow-Up

Patients should undergo repeat examination until symptoms have resolved completely.

Strength, sensation, and range of motion should be compared with the opposite side during follow-up.

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Prognosis

The prognosis after an isolated stinger is generally excellent.

Most athletes recover rapidly, and many miss little or no playing time.

In one rugby cohort, the average return to play was approximately 2.9 days, with the majority of athletes missing no competition.

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Duration of Symptoms

The mean symptom duration in one study was approximately 3.5 days, although most episodes resolved within 24 hours.

Longer-lasting symptoms are more concerning for a higher-grade nerve injury.

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Prognostic Factors

A history of repeated stingers with multiple associated symptoms, particularly motor weakness, is associated with greater injury severity.

Frequent recurrence should prompt investigation for underlying cervical stenosis or other structural abnormalities.

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Recurrence

Recurrence is one of the major clinical problems associated with stingers.

Some older studies reported recurrence rates as high as 87%, although rates vary considerably depending on sport, study population, and diagnostic criteria.

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Complications

The overall risk of permanent nerve damage after a simple isolated stinger is low.

However, recurrent episodes may occasionally lead to chronic neurologic symptoms or persistent weakness.

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Chronic Stinger Syndrome

A minority of athletes with frequent recurrent stingers can develop a more persistent syndrome.

Cervical stenosis has a strong association with chronic or recurrent symptoms in these patients.

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Patient Monitoring

A detailed neurologic examination should be performed at the time of injury and compared with the unaffected side.

The athlete should then be reassessed at regular intervals until pain, paresthesias, weakness, and all neurologic abnormalities have completely resolved.

Return to sport should occur only when the examination is normal and the athlete can perform sport-specific activities without recurrence.