Shoulder Dislocation Classifications (

Shoulder Dislocation Classifications (

Definition: Separation of the humerus from the scapula at the glenohumeral joint


  • Most commonly dislocated joint in the body  (17/100,000 people/year)
  • Young males most commonly injured


  • Anterior: 97% (Rowe 1956)
  • Posterior: < 3%
  • Inferior: < 1% (Also known as: Luxatio Erecta Humeri)
  • IMAGE:


  • Anatomy
    • Inherently unstable joint, relies on soft tissues for stabilization
    • Only 25-30% of humeral head articulates with glenoid at any one time
    • Axillary nerve wraps around surgical neck of humerus, most commonly injured nerve in dislocations of any direction
      • Motor: Deltoid muscle
      • Sensory: Anterolateral shoulder
  • Anterior:
    • Fall onto outstretched hand
    • Force/blow to abducted and externally rotated +/- extended arm (ie. Blocking basketball shot)
  • Posterior:
    • ~50% secondary to trauma (Matsen 2007)
    • 34% associated with seizures (Rouleau 2012)
      • Strongest shoulder muscles (latissimus dorsi, pectoralis major, subscapularis) overpower others and pull shoulder internally, posteriorly
      • Most common dislocation during seizures is anterior due to associated fall
  • Inferior:
    • Very high energy injuries. Hyperabduction force levers arm on acromion forcing the humeral head into the infraglenoid region
    • Concomitant injury rate (humerus fracture, rotator cuff tears) as high as 80% (Groh 2010)
    • Concomitant neurologic injury as high as 60% (Groh 2010)

physical-exam-netters-concise-orthopedic-anatomy-2nd-editionPhysical Examination:

  • Anterior
    • Arm is held in internally rotated and abducted position
    • Shoulder silhouette flattened with a prominent acromion

Netter’s Concise Orthopaedic Anatomy, Second Edition

  • Posterior
    • Arm is fixed, internally rotated, and adducted
    • Posterior shoulder prominence
  • Inferior
    • Fixed, abducted position 
    • Arm held above the head

X-Ray Imaging (All Images in Gallery Below):

  • For any suspected dislocation, obtain 3 views: AP, Scapula Y, and Axillary (see Approach to Traumatic Shoulder Pain for normal X-ray anatomy)
  • Anterior Dislocation
    • AP View: Humeral head dislocated anteriorly and rests under the coracoid process
    • Scapula Y View: Scapula Y view: humeral head displaced medially (to the right) of the scapula
    • Axillary view: Humeral head displaced anteriorly in front of the coracoid process
  • Posterior Dislocation
    • AP: “Light bulb on a stick” – often the only sign of a posterior dislocation. The humeral head does not appear displaced from the glenoid BUT it is internally rotated and thus the contour of the humeral head appears rounded – like a light bulb
    • Scapula Y: Humeral head displaced laterally (to the left) of the scapula
    • Axillary: Humeral head displaced posteriorly behind the coracoid process
  • Inferior Dislocation
    • Luxatio Erecta: Humeral head displaced inferior to glenoid and arm/humerus fixed above head/superiorly
Hill Sachs Lesion (

Hill Sachs Lesion (

Important Additional X-Ray Findings

  • Hill Sachs Lesion
    • Impaction fracture of humeral head against glenoid rim
    • Anterior dislocations,
      • Occurs against posterolateral surface
      • Incidence rate 40-90%
      • As high as 100% in recurrent dislocations (Provencher 2012)
    • Posterior dislocations
      • Occurs against anterolateral surface (“reverse Hill Sachs lesion”)
      • Incidence 86%.
    • May require accentuating rotational force (internal vs external) when reducing dislocation to dislodge the lesion off glenoid rim
  • Bankart Lesion
    • Detachment of anterior inferior labrum from glenoid
    • “Soft” – Labrum only
    • “Bony” – impaction fracture involving glenoid margin
Bankart Lesion (

Bankart Lesion (

Management/Reduction Techniques

  • Provide adequate analgesia
    • The more the patient tenses his or her muscles from pain, the more difficult it will be to reduce the joint
    • Consider systemic analgesia vs intraarticular local anesthetics vs both
    • Procedural sedation may be required in select cases
  • Complete a full neurologic and vascular assessment prior to the performance of any manipulation technique
  • Anterior
    • Cunningham Technique
      • Physician massages the patient’s biceps muscle as the patient holds arm adducted and elbow flexed
      • Patient gradually moves shoulders up and back (shoulder shrug) as tolerated

    • Stimson Maneuver
Stimson Maneuver (Netter's Concise Orthopedic Anatomy 2nd Edition)

Stimson Maneuver (Netter’s Concise Orthopedic Anatomy 2nd Edition)

    • Scapular Manipulation
      • Stimson technique applied
      • Scapula manipulated counterclockwise: stabilized superiorly, medial force applied on inferior angle
Scapular Manipulation with Stimson (

Scapular Manipulation with Stimson (

    • Traction-Countertraction
      • Gradual, smooth traction is applied to the affected arm until patient’s muscles relax or tire sufficiently to release the dislocated humeral head
      • An assistant maintains counter traction to maintain patient in place


    • Milch
Milch Technique (Netter's Concise Orthopedic Anatomy 2nd Edition)

Milch Technique (Netter’s Concise Orthopedic Anatomy 2nd Edition)

  • Posterior: requires 2 operators
    • Traction-Countertraction recommended for all posterior dislocations
    • Sitting patient upright and applying forward traction might be useful
  • Inferior
    • Arm traction superiorly with gradual shoulder adduction 
    • Sheet wrapped around upper torso to hold patient in place
    • Traction-Countertraction
    • Two-Step (Youm 2014)
      • Arm traction superiorly while pushing humerus laterally
      • This will either reduce the shoulder entirely or convert it to anterior dislocation, which can be reduced as above

Relative Contraindications to ED Reduction:

  • Associated fracture of humeral neck
  • Associated nerve injury/deficit
  • Suspected major vascular injury
  • Chronic Dislocation
    • > 48 hours
    • Success rate exceedingly low
    • Refer to orthopedics for surgical evaluation if initial attempts fail

Follow Up

  • Immobilize in sling for 3-4 weeks (older patients 1-2 weeks to avoid joint stiffening)
  • Rehab should begin with passive range of motion exercises
  • Anterior dislocations: no external rotation past neutral and no abduction past 90 degrees for the first 4-6 weeks
  • Posterior dislocations: no internal rotation for first 4-6 weeks.

Take Home Points:

  • Be vigilant for concomitant neurovascular injuries and always perform a full neurovascular assessment before and after reduction
  • Carefully review radiographs for posterior dislocations as they may appear “normal” on first glance
  • Be comfortable with multiple reduction techniques. No one approach will reduce all shoulder dislocations.
  • Joint injections and systemic analgesia will facilitate reduction. Depending on patient response to initial attempts, procedural sedation may be necessary.


Youm T et al. Acute Management of Shoulder Dislocations. J Am Acad Orthop Surg. 2014 Dec;22(12):761-771.PMID: 25425611.

Rowe CR: Prognosis in dislocations of the shoulder. J Bone Joint Surg Am 1956; 38(5):957-977 PMID 13367074

Matsen FA et al. Principles for the evaluation and management of shoulder instability. Instr Course Lect 2007; 56:23-34. PMID: 17472289

Rouleau DM et al. Incident of associated injury in posterior shoulder dislocation: Systematic review of the literature. J Orthop Trauma 2012 ;26(4):246-251. PMID: 22183196

Robinson CM, Aderinto J. Posterior shoulder dislocations and fracture- dislocations. J Bone Joint Surg Am 2005; 87 (3):639-650. PMID: 15741636

Patel DN et al. Luxatio erecta: Case series with review of diagnostic and management principles. Am J Orthop 2011;40(11): 566-570. PMID: 22263209

Groh GI et al. Results of treatment of luxatio erecta (inferior shoulder dislocation). J Shoulder Elbow Surg 2010;19(3):423-426. PMID: 19836975

Provencher MT et al. The Hill-Sachs lesion: Diagnosis, classification, and management. J Am Acad Orthop Surg 2012;20(4):242-252. PMID: 22474094

Schwartz D. Emergency Radiology Case Studies. Upper Extremity: Patient 6. 271-279. McGraw-Hill Education / Medical; 1 edition (November 26, 2007)

Thompson J, Netter F, Machado C. Netter’s Concise Orthopaedic Anatomy. Second edition. Saunders Elsevier 2010.