Acute Anterior Dislocation

EpidemiologyAnterior Shoulder Dislocation

 

Most common form of shoulder instability

- young males 

- M:F = 2:1

 

Aetiology

 

Indirect ER and abduction moment on arm

- disruption of anterior stabilisers

 

History

 

Initial injury

- severe pain in shoulder

- ± transient paraesthesia / dead arm syndrome

 

History of dislocations

 

Examination

 

Very painful & tender shoulder

- significant muscle spasm

- arm held across abdomen

 

Hollow under acromion

- fullness in anterior shoulder

 

Axillary nerve palsy

- important to exclude

- look for parasthesis in badge area

- 20 years = 5% --> 90% recover

- 80 years = 90% --> 10% recover

 

Left Deltoid Wasting

 

Musculocutaneous Injury + Rotator Cuff Tear

 

Musculocutaneous nerve injuryMusculocutaneous Nerve Injury 2Supraspinatous Infraspinatous Wasting

 

Diagnostic Dilemma

 

Patient with history traumatic dislocation / wasting of shoulder / loss ROM

1.  Wasting deltoid (AXN)

2.  Wasting SS, not IS (RC tear)

3.  Wasting SS & IS (SSN injury or massive tear)

4.  Wasted deltoid + SS/IS (upper trunk brachial plexus or AXN palsy with RC tear)

 

Axillary nerve palsy with Massive Rotator Cuff Tear

 

Xray

 

True AP

- dislocation

- fracture GT

- bony bankart

 

Shoulder Dislocation Greater Tuberosity FractureAnterior Shoulder Dislocation AP

 

AP in IR

- Hill Sachs lesion

 

Scapular Lateral

- dislocation

- humeral head should be in centre of Y

 

Anterior Shoulder Dislocation0002Shoulder Anterior Dislocation Scapula Lateral

 

Axillary Lateral

- dislocation

- Hill Sachs

 

Shoulder Fracture DislocationAnterior Shoulder Dislocation Axillary LateralShoulder Hill Sachs Axillary Lateral

 

Garth

- aim beam caudally

- bony bankart

 

Bony Bankart Xray

 

Classification

 

According to direction seen on xrays

1. Subcoracoid / most common

2. Subglenoid

3. Intrathoracic

 

Management

 

Reduction

 

ASAP

- appropriate analgesia & muscle relaxation / conscious sedation

- atraumatic closed reduction performed

- if unsuccessful, may require GA

- rarely need open reduction

 

Post-reduction xray

- confirm reduction

- rule out associated fracture

 

Shoulder Post Dislocation Check Reduction

 

Techniques

 

1.  Stimpson

- patient prone

- arm hanging over side of bed

- weight applied to wrist

- give mild sedation

- not appropriate if obese / sleep apnea etc

 

Stimpson Method

 

2.  Harvard / Traction & Countertraction method

- patient supine

- traction with abduction

- countertraction via sheet around axilla

- similar to Hippocratic but no foot in the axilla

 

3.  Kocher

- externally rotate and maximally abduct arm

- relocate via adduction

- nil IR til located to avoid humeral fracture

 

4.  Hippocrates

- foot in arm pit

- apply longitudinal traction 

 

Immobilisation

 

No effect on re-dislocation rate

- no sport for 6/52 reduces dislocation rate

 

Protocol

- sling for comfort

- avoid provocation 6/52

- no sport until painless FROM

 

ER brace

 

Theoretical

- tightens SSC
- reduces bankart lesion into anatomical location whilst healing

- may reduce redislocation rates

- problems with compliance as is uncomfortable and in young population

 

Itoi et al JBJS Am 2007

- RCT ER brace v sling 198 patients 3 weeks duration

- relative risk reduction 38%

- 26% recurrence v 42% (p < 0.03)

- particularly beneficial if < 30

 

Finestone et al JBJS Br 2009

- RCT 51 patients

- no difference

 

Rehabilitation

 

Start with ROM exercises

- pendulum / active Assisted / active

 

Progress to shoulder strengthening

 

Prognosis

 

1. Age at first dislocation

 

Increased in young

- the majority of recurrences occur within 2 years of the first traumatic dislocation

 

Classic paper Rowe CORR '61

- < 20    90% redislocation

- 20-30  60% redislocation

- 30-40   30% redislocation

- > 40     10% redislocation

 

McLaughlin and MacLellan 1967 

- 95% traumatic dislocations in teenagers recurred

 

Simonet and Cofield 1982 

- overall incidence of recurrence 33% over 4 years

- 66% in patients < 20 years

- 17% in patients 20 - 40 years

 

2. Trauma of First Dislocation

 

Decreased incidence of re-dislocation with 

- severe trauma

- associated fracture (usually LT / GT)

 

3. Activity

 

Re-dislocation more common in athletes

- 80% in athletes

- 30% in non-athletes

 

4. Rehabilitation

 

Activity restriction & effective muscle strengthening reduces re-dislocation

- overall re-dislocation rate 25% at 3 years in Army

- need strict adherence with program

 

Indications Operative Management in Acute Dislocation

 

1.  Rotator cuff tear

2.  Displaced GT fracture

3.  Large glenoid rim fracture

4.  ? Athlete

 

Rotator cuff tear

 

Diagnosis

 

Important not to miss

- high incidence in patients > 40

- suspect if pain or decreased ROM

- MRI

 

Incidence

 

Berbig et al J Should Elbow Surg 1999

- prospect ultrasound on 167 patients with dislocation

- full thickness tears in 31.7%

- only acute tears in patients younger than 60

- control group had no FT tears in patients younger than 60

 

Management Options

 

A.  Repair RC / leave Bankart

B.  Repair RC and Bankart

 

Voos et al Am J Sports Med 2007

- retrospective review of arthroscopic repair of RC and labrum

- average age 47, 16 patients

- good or excellent results in > 90%

 

2.  Displaced GT Fracture

 

Indications

- > 5 mm displacement

 

Management

- ORIF

- screw + suture repair

- screw alone in young patient

 

Shoulder Dislocation Non Displaced GT FractureGT ORIF

 

3.  Large Glenoid Rim Fracture

 

Indications

- > 25 - 30% and displaced

 

Management

- open or arthroscopic

- fix with 1 or 2 cannulated screws

 

Glenoid Rim FractureGlenoid Rim Fracture CTGlenoid Rim ORIF

 

4.  Acute dislocation in professional athlete

 

Robinson et al JBJS Am 2008

- prospective randomised control trial arthroscopic surgery in first time dislocators

- 88 patients under 35, arthroscopic stabilisation v arthroscopic lavage

- reduced risk of recurrence by 80%

- patient satisfaction and shoulder scores significantly improved

 

Kirkley et al Arthroscopy 2005

- RCT of 40 patients for arthroscopic stabilisation v immobilisation

- 3 recurrences in surgical group, 9 in non surgical group

- small improvement in shoulder scores in operative group

 

Jakobsen et al Arthroscopy 2007

- RCT 76 patients

- arthroscopy to diagnose labral injury

- either open repair or non operative

- 74% unsatisfactory results at 8 years in non operative group

- 75% good results in operative group (1 redislocation)