Scapulothoracic Dissociation

Author: Tracy Jones

Topic updated on 05/06/13 6:58am

Introduction

A traumatic disruption of the scapulothoracic articulation often associated with
- severe neurologic inuries
- vascular injuries
- orthopaedic injuries
Mechanism
- usually caused by a lateral traction injury to the shoulder girdle
- involves significant trauma to heart, chest wall and lungs
Associated conditions
- orthopaedic
  - scapula fractures
  - clavicle fractures
  - AC dislocation/separation
  - sternoclavicular dislocation
  - flail extremity (52%)
    - the injury results in complete loss of motor and sensory function rendering the extremity non-functional
- vascular injury
  - subclavian artery most commonly injured
  - axillary artery
- neurologic injury
  - ipsilateral brachial plexus injury
  - neurologic injuries more common than vascular injuries
Prognosis
- mortality rate of 10%
- functional outcome is dependent on neurologic injury
  - if return of neurological function is unlikely, early amputation is recommended

Anatomy

Scapulothoracic joint
- a sliding joint
- articulates with ribs 2-7
- moves into abduction at 2:1 ratio
  - GH joint 120°
  - ST joint 60°
Neurovascular anatomy
- brachial plexus
- subclavian artery
- axillary artery

Presentation

History
- history of high energy trauma
Symptoms
- pain in involved upper extremity (UE)
- numbness/tingling in involved UE
Physical exam
- inspection
  - significant swelling in shoulder region
  - bruising around shoulder
- vascular exam
  - decreased or absent pulses in involved UE
- neurological exam
  - neurologic deficits in UE
  - neurological status critical part of exam

Imaging

Radiographs
- required views
  - AP chest
- recommended view
  - AP and lateral of shoulder as tolerated
  - appropriate images of suspected fracture sites
- findings
  - laterally displaced scapula
    - edge of scapula displaced > 1 cm from spinous process as compared to contralateral side
  - widely displaced clavicle fx
  - AC separation
  - sternoclavicular dislocation
Angiogram
- indicated to detect injury to subclavian and axillary artery

Treatment

Nonoperative
- immobilization/supportive care
  - indications
    - patients without significant vascular injury who are hemodynamically stable
      - patients may have adequate collateral flow to UE even with injury
Operative
- high lateral thoracotomy with vascular repair
  - indications
    - axillary artery injury in hemodynamically unstable patient
- median sternotomy with vascular repair
  - indications
    - more proximal arterial injury (i.e., subclavian artery) in a hemodynamically unstable patient
- ORIF of the clavicle or AC joint
  - indications
    - associated clavicle and AC injuries
- forequarter amputation
  - indications
    - complete brachial plexus injury

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Qbank (2 Questions)

TAG

(OBQ10.20) A 30-year-old male sustains a right shoulder injury with initial radiographs shown in Figures A and B. What single piece of additional information would best assist in determining this patient's functional outcome? Topic

Review Topic

FIGURES: A

1. Lower extremity injury
2. Neurological deficit
3. Contralateral upper extremity injury
4. Proximal humerus fracture
5. Worker's compensation

PREFERRED RESPONSE ▶

DISCUSSION: Figures A and B show a scapulothoracic dissociation, with significant lateralization of the scapula and widening of the acromioclavicular joint to over 4 cm (Figure A). This can be thought of as an internal disarticulation of the scapulothoracic association and acromioclavicular joints.

The referenced article by Riess et al revealed that functional outcomes are worse with brachial plexus injuries and concomitant scapulothoracic dissociation than with isolated brachial plexus injuries. In fact, at 2 year follow-up, only 57% of the dissociation patients could carry anything over 5 lb with the injured side.

The other referenced article by Zelle et al found that complete brachial plexus injuries portended the worst outcome for scapulothoracic dissociation injuries.

REFERENCES:

1. Riess KP, Cogbill TH, Patel NY, Lambert PJ, Mathiason MA. Brachial plexus injury: long-term functional outcome is determined by associated scapulothoracic dissociation. J Trauma. 2007 Nov;63(5):1021-5. PMID:17993946 (Link to Abstract)

2. Zelle BA, Pape HC, Gerich TG, Garapati R, Ceylan B, Krettek C. Functional outcome following scapulothoracic dissociation. J Bone Joint Surg Am. 2004 Jan;86-A(1):2-8. PMID:14711938 (Link to Abstract)

Question Authors:

Ben Taylor MD, Michael Hughes MD,

Please Rate Educational Value!

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TAG

(OBQ10.52) A patient presenting with scapulothoracic dissocation and ipsilateral extremity neurologic injury is most likely to have which of the following outcomes? Topic

Review Topic

1. Glenohumeral arthritis
2. Return of 3/5 motor strength in distal extremity
3. Full return of extremity sensory function only
4. Flail extremity
5. Death

PREFERRED RESPONSE ▶

DISCUSSION: Scapulothoracic dissociation is a high-energy injury resulting from massive traction injury to the shoulder girdle with disruption of the scapulothoracic articulation. The most common long term result from this injury is complete loss of motor and sensory function of the extremity (flail limb), with death in the acute or semi-acute period also common.

The referenced study by Althausen et al found that outcomes from this injury were: a flail extremity in 52%, early amputation in 21%, and death in 10%.

The other referenced study by Ebraheim et al found that 12/15 patients had a complete brachial plexus injury and that none recovered any function (the other 3 patients died in the acute period).

REFERENCES:

1. Althausen PL, Lee MA, Finkemeier CG. Scapulothoracic dissociation: diagnosis and treatment. Clin Orthop Relat Res. 2003 Nov;(416):237-44. PMID:14646766 (Link to Abstract)

2. Ebraheim NA, An HS, Jackson WT, Pearlstein SR, Burgess A, Tscherne H, Hass N, Kellam J, Wipperman BU. Scapulothoracic dissociation. J Bone Joint Surg Am. PMID:3346268 (Link to Abstract)

Question Authors:

Ben Taylor MD, Jan Szatkowski MD, Michael Hughes MD,

Please Rate Educational Value!

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Average 3.0 of 13 Ratings

Videos

Scapulothoracic Dissociation - Everything You Need To Know - Dr. Nabil Ebr

Trauma - Educational Presentation - Scapulothoracic Dissociation

Education video discussing the condition and treatment of scapulothoracic dissoc...

3/29/2013

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Groups

ABOS II: Scapulothoracic Dissociation

General - Oral Boards Review

7/29/2011

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Evidence & References Show References

Level of Evidence 2 (Prospective Cohort Study)

Zelle BA, Pape HC, Gerich TG, Garapati R, Ceylan B, Krettek C. Functional outcome following scapulothoracic dissociation. J Bone Joint Surg Am. 2004 Jan;86-A(1):2-8. PMID:14711938 (Link to Abstract)

Level of Evidence 3 (Retrospective Cohort Study or Case-Control Study)

Althausen PL, Lee MA, Finkemeier CG. Scapulothoracic dissociation: diagnosis and treatment. Clin Orthop Relat Res. 2003 Nov;(416):237-44. PMID:14646766 (Link to Abstract)

Level of Evidence 4 (Case Series)

Ebraheim NA, An HS, Jackson WT, Pearlstein SR, Burgess A, Tscherne H, Hass N, Kellam J, Wipperman BU. Scapulothoracic dissociation. J Bone Joint Surg Am. PMID:3346268 (Link to Abstract)
Riess KP, Cogbill TH, Patel NY, Lambert PJ, Mathiason MA. Brachial plexus injury: long-term functional outcome is determined by associated scapulothoracic dissociation. J Trauma. 2007 Nov;63(5):1021-5. PMID:17993946 (Link to Abstract)

Textbooks

Review of Orthopaedics, 6th Edition, Mark D. Miller MD, Stephen R. Thompson MBBS MEd FRCSC, Jennifer Hart MPAS PA-C ATC, an imprint of Elsevier, Philadelphia, Copyright 2012
AAOS Comprehensive Orthopaedic Review, Jay R. Leiberman. Published by American Academy of Orthopaedic Surgeons, Rosemont IL. Copyright 2009
Orthopaedic Knowledge Update 10, John M Flyn. Published by American Academy of Orthopaedic Surgeons, Rosemont IL. Copyright 2011
Hoppenfeld SP. Surgical Exposures in Orthopaedics: The Anatomic Approach. Lipponcott, Williams, and Wilkins, Philadelphia, PA, Copyright 2009
Orthopaedic In-training Examination (OITE) Questions 2004-2012, American Academy of Orthopaedic Surgeons, Rosemont IL. Copyright 2004-2012
Self-Assessment Examination (SAE) Questions 2004-2012, American Academy of Orthopaedic Surgeons, Rosemont IL. Copyright 2004-2012

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Scapulothoracic Dissociation

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