Scapula Fractures - Trauma

summary
- Scapula Fractures are uncommon fractures to the shoulder girdle associated with high energy trauma, associated pulmonary or head injury, and increased injury severity scores.
- Diagnosis can be made with plain radiographs. CT studies are helpful for fracture characterization and for surgical planning.
- Treatment is generally nonoperative in a sling. Surgical management is indicated for intra-articular fractures, displaced scapular neck fractures, open fractures, and those associated with glenohumeral instability.

Epidemiology
- Incidence
  - Rare
    
    less than 1% of all fractures
- Anatomic location
  - 50% involve body and spine

Etiology
- Associated injuries (in 80-90%)
  - orthopaedic
    
    rib fractures (52%)
    
    ipsilateral clavicle fracture (25%)
    
    spine fracture (29%)
    
    brachial plexus injury (5%)
    
    75% of brachial plexus injuries resolve
  - medical
    
    pulmonary injury
    
    pneumothorax (32%)
    
    pulmonary contusion (41%)
    
    head injury (34%)
    
    vascular injury (11%)

                        Classification
                    
                        Classification is based on the location of the fracture and includes
                    
                        coracoid fractures
                    
                        acromial fractures
                    
                        glenoid fractures
                    
                        scapular neck fractures 
                    
                        look for associated AC joint separation or clavicle fracture
                    
                        known as "floating shoulder"
                    
                        scapular body fractures 
                    
                        described based on anatomic location
                    
                        scapulothoracic dissociation
                    
                                            Coracoid Fracture Classification
                                        
                                            Type I
                                        
                                            Fracture occurs proximal to the coracoclavicular ligament
                                        
                                            Type II
                                        
                                            Fracture occurs towards the tip of the coracoid
                                        
                                            Acromial Fracture Classification
                                        
                                            Type I
                                        
                                            Nondisplaced or minimally displaced
                                        
                                            Type II
                                        
                                            Displaced but does not compromise the subacromial space
                                        
                                            Type III
                                        
                                            Displaced and compromises the subacromial space
                                        
                                            Ideberg Classification of Glenoid Fracture
                                        
                                            Type Ia
                                        
                                            Anterior rim fracture
                                        
                                            Type Ib
                                        
                                            Posterior rim fracture
                                        
                                            Type II
                                        
                                            Fracture line through glenoid fossa exiting scapula laterally
                                        
                                            Type III
                                        
                                            Fracture line through glenoid fossa exiting scapula superiorly
                                        
                                            Type IV
                                        
                                            Fracture line through glenoid fossa exiting scapula medially
                                        
                                            Type Va
                                        
                                            Combination of types II and IV
                                        
                                            Type Vb
                                        
                                            Combination of types III and IV
                                        
                                            Type Vc
                                        
                                            Combination of types II, III, and IV
                                        
                                            Type VI
                                        
                                            Severe comminution

Imaging
- Radiographs
  - recommended views
    
    true AP, scapular Y and axillary lateral view
- CT
  - intra-articular fracture
  - significant displacement
  - three-dimensional reconstruction useful

Treatment
- Nonoperative
  - sling for 2 weeks, followed by early motion
    
    indications
    
    indicated for vast majority of scapula fractures
    
    90% are minimally displaced and acceptably aligned
    
    outcomes
    
    union at 6 weeks
    
    can expect no functional deficits
- Operative
  - open reduction internal fixation
    
    indications
    
    glenohumeral instability
    
    > 25% glenoid involvement with subluxation of humerus
    
    > 5mm of glenoid articular surface step off or major gap
    
    excessive medialization of glenoid
    
    displaced scapula neck fx
    
    with > 40 degrees angulation or 1 cm translation
    
    open fracture
    
    loss of rotator cuff function
    
    coracoid fx with > 1cm of displacement
    
    "double disruption" of the superior shoulder suspensory complex
    
    outcomes
    
    70% good to excellent results with operative treatment

Technqiues
- Open Reduction Internal Fixation of Scapula
  - approach
    
    based on fracture location
    
    Judet approach is most common
    
    utilizes internervous plane between infraspinatus (suprascapular nerve) and teres minor (axillary nerve)

Coracoid Fracture Classification
Type I	Fracture occurs proximal to the coracoclavicular ligament
Type II	Fracture occurs towards the tip of the coracoid

Acromial Fracture Classification
Type I	Nondisplaced or minimally displaced
Type II	Displaced but does not compromise the subacromial space
Type III	Displaced and compromises the subacromial space

Ideberg Classification of Glenoid Fracture
Type Ia	Anterior rim fracture
Type Ib	Posterior rim fracture
Type II	Fracture line through glenoid fossa exiting scapula laterally
Type III	Fracture line through glenoid fossa exiting scapula superiorly
Type IV	Fracture line through glenoid fossa exiting scapula medially
Type Va	Combination of types II and IV
Type Vb	Combination of types III and IV
Type Vc	Combination of types II, III, and IV
Type VI	Severe comminution