Inferior Glenohumeral Dislocation
- Luxatio erecta humeri is an INFERIOR glenohumeral dislocation - the humeral head lies below the glenoid and the arm is locked RIGIDLY HYPERABDUCTED above the head, a position the patient cannot reverse; it is the rarest type of shoulder dislocation (under 1%) and the diagnosis is a 'spot diagnosis' on the clinical picture and AP radiograph (the abducted humeral shaft points superolaterally with the head inferior to the glenoid).
- The mechanism is either a direct AXIAL LOAD applied to a fully abducted extremity, or a HYPERABDUCTION force that levers the humeral head inferiorly across the acromion - the two recognised pathomechanics.
- There is a HIGH incidence of NEUROVASCULAR injury: brachial plexus and axillary nerve neuropraxia (and radial/ulnar involvement) and axillary ARTERY injury (intimal tear, transection or thrombosis) or venous injury - so a careful neurovascular examination MUST be documented before and after reduction, and vascular compromise requires urgent assessment.
- Associated MUSCULOSKELETAL injuries are common: ROTATOR-CUFF tears, greater-tuberosity avulsion, and impaction defects of the humeral head (and fractures of the acromion, clavicle or coracoid) - the cuff injury in particular drives later morbidity, so the cuff should be assessed after reduction.
- Closed reduction is by TRACTION-COUNTERTRACTION: axial traction along the abducted arm with countertraction over the shoulder, gradually bringing the arm into adduction (a 'two-step' technique converts it to an anterior-type position then reduces); it is usually achieved under sedation/analgesia, with rare cases (button-holing of the head through the capsule) needing open reduction.
- After reduction the arm is immobilised in a sling in ADDUCTION, neurovascular status and the rotator cuff are re-checked, and follow-up addresses the high rates of recurrent instability, residual cuff dysfunction and adhesive capsulitis; orthopaedic referral is warranted because of the frequent cuff injury.
- “Luxatio erecta = INFERIOR dislocation: arm LOCKED hyperabducted ABOVE the head (cannot bring it down) - unmistakable spot diagnosis.
- “HIGH neurovascular risk (brachial plexus/axillary nerve, axillary artery) + rotator-cuff/greater-tuberosity injury - examine before AND after reduction.
- “Reduce by TRACTION-COUNTERTRACTION (or two-step) under sedation, then sling in adduction; rare button-hole cases need open reduction.
Arm locked hyperabducted above the head, elbow flexed, forearm resting on or behind the head - the patient cannot bring it down. The head is palpable on the lateral chest wall.
Neurovascular injury (brachial plexus / axillary artery) and rotator-cuff / greater-tuberosity damage are common - examine and document before and after reduction.
Mechanism, Recognition & Associated Injury
Luxatio erecta is the inferior glenohumeral dislocation - the rarest type (under 1% of shoulder dislocations) - and is produced either by an axial load on a fully abducted arm or by a hyperabduction force that levers the humeral head inferiorly over the acromion. The presentation is unmistakable: the arm is held rigidly hyperabducted above the head and cannot be brought down, with the head palpable on the lateral chest wall. Despite the dramatic, easy picture, the company it keeps is dangerous - there is a high incidence of brachial plexus / axillary nerve neuropraxia, axillary artery injury (intimal tear, transection or thrombosis), and rotator-cuff tears with greater-tuberosity avulsion and humeral-head impaction. It is frequently misdiagnosed as an anterior dislocation if the classic position is not appreciated.
Reduction & Aftercare
- Assess first: document neurovascular status (brachial plexus, axillary nerve, distal pulses/perfusion) - and re-check after reduction.
- Closed reduction (traction-countertraction): apply axial traction along the line of the abducted humerus with countertraction across the shoulder (a sheet over the shoulder), and gradually swing the arm into adduction to relocate the head. Performed under sedation/analgesia.
- Two-step technique: convert the inferior dislocation to an anterior-type position and then reduce - useful when straight traction-countertraction is difficult.
- Open reduction is reserved for the irreducible case (e.g. the head 'button-holed' through a capsular rent) or for associated injuries requiring fixation.
- After reduction: immobilise in a sling in adduction, confirm relocation and neurovascular status radiographically/clinically, and assess the rotator cuff - referral is warranted because of the high rate of cuff injury.
The single most important habit in luxatio erecta is a documented neurovascular examination BEFORE and AFTER reduction, because the brachial plexus / axillary nerve and the axillary artery are frequently injured by the inferiorly displaced head, and a vascular injury (intimal tear, thrombosis or transection) can be limb- threatening and is easy to overlook in the drama of the obvious deformity. After relocation, re-examine the nerves and the pulse and assess the rotator cuff, since an unrecognised cuff tear or arterial injury changes management. Treat luxatio erecta as a high-energy shoulder injury with dangerous associations, not merely as a striking position to be reduced.
Evidence & Key Studies
Luxatio erecta humeri (pathomechanics, neurovascular injury, reduction and morbidity)
- Pathomechanics involve either direct axial loading on a fully abducted extremity or leverage of the humeral head across the acromion by a hyperabduction force; the affected arm is held rigidly above the head in abduction.
- Reduction is by traction-countertraction under sedation and analgesia; a variety of neurologic (brachial plexus) and vascular (axillary artery) injuries may be associated, along with fractures of the acromion, clavicle, coracoid, greater tuberosity and humeral head.
- It is associated with significant late morbidity including recurrent dislocation, instability and adhesive capsulitis.
Luxatio erecta: a rarely seen, but often missed shoulder dislocation
- Luxatio erecta is often misdiagnosed as an anterior dislocation; the presentation is unmistakable - the arm hyperabducted and locked above the head.
- Neurovascular injuries include neuropraxia of the brachial plexus and radial/ulnar nerves, and axillary artery/vein injury (intimal tears, transection, thrombosis).
- Reduction is by the traction-countertraction manoeuvre, after which the arm is maintained in a sling in adduction; orthopaedic referral is required because of the high incidence of rotator-cuff injury.
According to PubMed, the pathomechanics (axial load on an abducted arm or hyperabduction leverage over the acromion), the traction-countertraction reduction, the spectrum of neurovascular injury (brachial plexus / axillary nerve and axillary artery/vein) and associated fractures, and the late morbidity (recurrent instability, adhesive capsulitis) come from the cited Davids report; the frequent misdiagnosis as anterior dislocation, the radial/ulnar neuropraxia and the high rate of rotator-cuff injury from the cited Grate review. The 'two-step' reduction technique and aftercare are standard, well-established teaching. (See also our Anterior Shoulder Instability and Rotator Cuff Tears topics.)
Clinical Decision Scenarios
Practise clinical reasoning and management decisions out loud
“A patient arrives with the arm fixed above the head and cannot bring it down. What is the diagnosis and how do you manage it?”
“What associated injuries and complications would you specifically look for after reducing a luxatio erecta?”
Mnemonics & Memory Aids
ERECTA
Hook:ERECTA: arm Elevated, Rotator cuff torn, Examine nerves, check Circulation, Traction reduction, Adduction sling.
Recognition
- Inferior glenohumeral dislocation - rarest type (under 1%)
- Arm locked rigidly hyperabducted above the head; cannot adduct
- Head palpable on lateral chest wall; AP X-ray: head below glenoid, shaft superolateral
Mechanism
- Axial load on a fully abducted arm, OR
- Hyperabduction force levering the head inferiorly over the acromion
- Often misdiagnosed as anterior dislocation
Associated injury
- Neurovascular: brachial plexus/axillary nerve neuropraxia; axillary artery injury
- Rotator-cuff tear, greater-tuberosity avulsion, humeral-head impaction
- Fractures of acromion, clavicle, coracoid
Management
- Document neurovascular status before AND after reduction
- Traction-countertraction (or two-step) under sedation; sling in adduction
- Open reduction if button-holed/irreducible; orthopaedic follow-up for the cuff