Spinal Trauma

Anatomy Least stable of all joints; muscles and rotator cuff cause stability; few ligaments

Anterior Dislocation

MOI: abduction, external rotation and extension; displaced antero mediallyTypes: 70% subcorocoid, 30% subglenoid, subclavicular, intrathoracic; chronic subluxuation common in elderly; fracture-dislocation more common if >40yrs, 1st dislocation, fall >1 flight of stairs, fight, MVA (otherwise fracture-dislocation unlikely); recurrent in 50% (usually related to Bankart lesion and lesion in inf glenohumeral ligament)

Complications: Rotator cuff injury (especially subscapularis; in 86% if >40yrs) Greater tuberosity fracture (10-15%; doesn’t change managemtn; if significantly displaced, likely rotator cuff tear) Fracture humeral neck Arterial compromise (usually axillary artery in elderly patients; lateral thorax bruising, axillary bruit, absent radial pulse) Bankart lesion (avulsion of anterior glenoid labrum, tear anterior capsule, associated with recurrent dislocations, arthroscopic repair may be attempted) Hill-Sachs deformity (compression fracture of post-lat humeral head due to abrasion by glenoid) dysfunction of subscapularis; occurs in recurrent dislocations, incidence 25-75%) Brachial plexus injury (especially if >50yrs, assoc fracture, haematoma; multiple nerves in 50%; usually incomplete injury; sensory recovery faster than motor; usually good prognosis with recovery within 3/12) Axillary nerve injury (most common neuro injury; occurs in 40% if EMG tested, 10-25% clinically) Other nerve injury (suprascapular 15%, musculocutaneous 10%, radial/ulnar 7%, median 5%) Recurrent dislocation (<20yrs, >90% recurrence rate; >40yrs, 10-15% recurrence rate)

Epidemiology 95% anterior, 1% posterior; rarely posterior or subglenoid

Reduction

Traction/Countertraction: traction on abducted arm with elbow flexed (with gentle internal / external rotation of arm or lateral pressure on proximal humerus) while countertraction to torsiExternal rotation: externally rotate only; 78% success rateKocher’s: externally rotate abduct flex adduct internal rotate; risk of tears of inferior capsule and fracture of anterior labrum or humerus; painfulCunningham: patient seated; humerus adducted; arm on doc’s shoulder patient shrugs shoulders up and back biceps massaged at mid-humeral levelMilch: patient supine operator’s hand fixes humeral head to prvent downward movement (or fix scapula if patient seated) arm abducted and externally rotated to over-head position traction applied can push humeral head over lip of glenoidStimson: 5-10kg weight to arm for 20mins; may need internal / external rotationSpaso: supine arm lifted vertically while traction applied slight external rotationScapular rotation: elbow flexed, wrist secured 5kg traction for few minutes rotate inferior cangle medially and superiorly, glenoid laterally and inferiorly; 96% success rate

No evidence that immobilisation reduces recurrence rate; 4/52 for 1st dislocation, few days for recurrent; OT if >4 dislocations

Posterior Dislocation

Subacromial > subglenoid, subspinousMOI: internal rotation and adduction; electrocution and seizures; may be bilateral; can also occur with blow to anterior shoulder; often associated with posterior glenoid and reverse Hill-Sachs deformity; NVI less commonReduction: traction with arm at 90° abduction and external rotation; or traction to adducted arm and assistant pushes humeral head anteriorlyComplications: fracture posterior glenoid rim, reverse Hill-Sachs (fracture humeral head / shaft / lesser tuberosity)

Rare; head dislocates inferior to glenoidComplications: significant risk of NVI (60% have neuro injury, usually axillary); 80% have rotator cuff injury or fracture; fracture proximal humerusMOI: arm forceably hyperabducted presents with arm hyperabducted and hand in overhead position, elbow flexedManagement: need reduction ASAP via traction on abducted arm in line of humerus clunk then swing arm into adduction

Luxatio Erecta