Signs and Symptoms
- Severe pain in the affected shoulder
- Anterior dislocation:
- Shoulder is squared off
- Prominent acromion process and palpable anterior fullness; defect under acromion where humeral head should be
- Arm is held in slight abduction and external rotation
- Posterior dislocation:
- Coracoid process is prominent, with a palpable posterior bulge
- Arm is held in slight adduction and internal rotation
- Inferior dislocation (luxatio erecta):
- Rare but easy to identify
- Arm is shortened and fixed above head as if raised to ask a question
- Head of humerus may be palpable on the lateral chest wall
Essential Workup
- Evaluate neurovascular status of distal arm
- Test tip of shoulder (axillary nerve)
- Retest neurovascular status after any manipulation
- Dislocation requires prompt treatment:
- Incidence of posttraumatic arthritis increases with time dislocation is untreated
- Plain films of the shoulder should be obtained immediately
- Even in clinically obvious cases, films should be obtained before manipulation, unless a significant delay will result
- An impacted humeral head fracture may be converted to a displaced humeral head fracture if manipulated
Diagnostic Tests & Interpretation
Imaging
- At least 2 views should be obtained:
- Anteroposterior (AP):
- To visualize dislocation or fracture
- Transscapular Y or axillary view:
- To visualize if anterior or posterior
- Anterior dislocation:
- Posterolateral compression fracture of the humeral head (Hill-Sachs deformity)
- Corresponding lesion on anterior glenoid rim is the Bankart lesion:
- These do not require treatment
- Fractures of the greater tuberosity of the humeral head are seen in 15-35%:
- If there is >1 cm displacement after reduction, surgical intervention may be necessary
- Posterior dislocation:
- Degree of overlap on radiographic film is smaller and displaced superiorly, producing the “meniscus sign”
- Rotated humerus yields “light bulb on a stick” finding on AP view:
- Reverse Hill-Sachs deformity from compression fracture of the anterior medial humeral head may also be seen
Differential Diagnosis
- Fracture of the humeral head
- Fracture of the humeral shaft
- Acromioclavicular injury
- Septic shoulder joint
- Hemarthrosis in shoulder joint
- Scapular fracture
- Cervical spine injury
Prehospital
Neurovascular injury should be identified and the arm splinted in the position of most comfort
Initial Stabilization/Therapy
- Airway management and resuscitate as indicated
- Exclude more serious injuries, especially in multitrauma patient
- Ensure no injury to axillary nerve or vessels
ED Treatment/Procedures
- Adequate analgesia and muscle relaxation are essential for successful reduction:
- Procedural sedation with a short-acting opioid and a benzodiazepine OR
- Ketamine, methohexital, or etomidate alone
- In the cooperative patient, intra-articular block only (20 cc of lidocaine 1% or bupivacaine 0.5%) into shoulder joint
- Anterior dislocation reduction techniques:
- Scapular manipulation:
- Patient seated, traction to arm in horizontal plane, countertraction with other hand on clavicle
- Second person adducts tip of scapula medially, moving glenoid fossa
- Stimson:
- Patient in prone position with arm dangling over side, hang 10-15 lb around wrist; muscle fatigued over 20-30 min
- Can concurrently use scapular manipulation
- Only 1 person required
- Traction/countertraction:
- Patient in supine position with continuous longitudinal traction to affected arm
- Countertraction from sheet wrapped around chest
- Arm internally or externally rotated if unsuccessful after several minutes
- External rotation:
- Patient supine; elbow at 90°; gentle, slow external rotation and abduction of arm
- Should be done slowly and with cooperative patient
- Posterior dislocation reduction techniques:
- May use Stimson or traction/countertraction techniques with manipulation of humeral head anteriorly
- Inferior dislocation (luxatio erecta) reduction techniques:
- Patient in supine position; gentle longitudinal traction cephalad to distract humeral head
- Gentle countertraction with sheet draped over trapezius and chest
- Arm slowly rotated from 180-0°
- Multiple alternate methods for reduction described in the literature
- Postreduction care:
- Postreduction films
- Place in sling and swath or shoulder immobilizer immediately after reduction
- Shoulder should remain immobilized for 2-3 wk in young patients
- Immobilization time should be less in older patients to avoid frozen shoulder
Medication
- Bupivacaine 0.5%: 20 mL intra-articular to shoulder
- Diazepam: 5-10 mg IV (peds: 0.2 mg/kg)
- Etomidate: 0.2 mg/kg IV (adult and peds)
- Fentanyl: 50-100 mcg IV (peds: 2-4 mcg/kg)
- Ketamine: 1-2 mg/kg IV, 2-4 mg/kg IM (adult/peds)
- Lidocaine 1%: 20 cc intra-articular to shoulder
- Methohexital: 1-1.5 mg/kg IV (peds: Not routinely used)
- Midazolam: 2-5 mg IV (peds: 0.035-0.1 mg/kg)
- Morphine: 2-8 mg IV (peds: 0.1 mg/kg); use preservative-free formulation
- Propofol: 1-2 mg/kg IV
- See“Procedural Sedation”
- KahnJ. The role of post-reduction x-rays after dislocation . Acad Emerg Med. 2001;8(5):521.
- LerouxT, WassersteinD, VeilletteC, et al. Epidemiology of primary anterior shoulder dislocation requiring closed reduction in Ontario, Canada . Am J Sports Med. 2014;42(2):442-450.
- McNamaraRM. Reduction of anterior shoulder dislocations by scapular manipulation . Ann Emerg Med. 1993;22(7):1140-1144.
- PerronAD, IngerskiMS, BradyWJ, et al. Acute complications associated with shoulder dislocation at an academic emergency department . J Emerg Med. 2003;24(2):141-145.
- StafylakisD, AbrassartS, HoffmeyerP. Reducing a shoulder dislocation without sweating. The Davos technique and its results. Evaluation of a nontraumatic, safe, and simple technique for reducing anterior shoulder dislocations . J Emerg Med. 2016;50(4):656-659.
- UfbergJW, VilkeGM, ChanTC, et al. Anterior shoulder dislocations: Beyond traction-countertraction . J Emerg Med. 2004;27(3):301-306.
The authors gratefully acknowledge Doodnauth Hiraman for his contribution to the previous edition of this chapter.