Introduction

  • Rare : 3-5% of shoulder girdle injuries
  • Requires high energy trauma, e.g. MVA
  • 10% mortality rate due to associated injuries
  • 80% of patients are male

Ossification

  • Forms in cartilage by 6th week
  • Primary ossification centre at glenoid angle by 8th week
  • By birth blade and spine are ossified
  • Secondary centres :
    • 3-18 months : mid-coracoid
    • 10 y/o
      • Base of coracoid
      • Upper 1/3 glenoid
      • Both fuse to rest of coracoid at puberty
    • Puberty
      • Tip of coracoid
      • Acromion
      • Medial border
      • Inferior angle
      • Lower margin of glenoid
      • These fuse at 25 y/o
      • Failure of the acromial secondary centres to fuse to the body makes an os acromiale

Classification

Type

  1. Fracture of the body
  2. Fracture of the apophysis, including the coracoid and acromion
  3. Fracture of the superolateral angle, including the neck and glenoid

Glenoid fracture (intra-articular)

  • Classified according to Ideberg:
  1. Anterior avulsion fracture
  2. Transverse fracture through the glenoid with an inferior triangular fragment displaced with the humeral head
  3. Oblique fracture through the glenoid exiting at the mid superior border of the scapula
  4. Horizontal fracture, exiting through the medial border of the blade
  5. Combines type 4 with a fracture separating the inferior part of the glenoid 

Associated injuries

  • Common; Reflects the high energy required to fracture the scapula
  • 90% incidence of associated injuries
    • PTX (30%)
    • Lung contusion (10%)
  • Skeletal
    • Ipsilateral extremity injuries (50%) (clavicle in 25%)
    • Spine injuries (15%)
    • Rib fractures (the most common)
  • Brachial plexus injury(5% -majority of which resolve)
  • Head injuries (34%)
  • Vascular injuries

Imaging

  • Radiographs
    • AP, scapular Y, axillary
    • 35 – 60 degrees cephalic tilt views to see coracoid
  • CT
    • Indications: intra-articular fractures; significantly displaced fractures of body

Treatment

Type 1: Fracture of the body

  • Support and symptomatic relief
  • Early ROM exercises to maintain function
  • Consider ORIF for fractures with 40 degrees of scapular body angulation on scapular Y view and for floating shoulder injuries

Type 2: Fracture of the apophysis, including the coracoid and acromion

  • Fracture of acromion
    • Undisplaced fracture : symptomatic relief, sling for short period
    • Displaced fracture (>1cm) may require ORIF if causing impingement or if needs reduction of AC joint; otherwise treat non operatively
  • Fracture of coracoid
    • Treat non operatively, unless grossly displaced (>1cm) or causing NV compromise
    • Can ORIF or can excise the fragment and reattach muscles to the base of the process without causing problems

Type 3:Fracture of the superolateral angle, including the neck and glenoi

  • Glenoid neck (extra-articular)
    • Reduction not necessary in most cases
    • Symptomatic relief, support, early ROM 
    • Surgical Indications:
      • Glenoid medialization of greater than 2cm
      • Greater than 40 degrees of angulation
      • Glenopolar angle <20 degrees
    • If associated with floating shoulder, ORIF of the clavicle may make rehabilitation faster
  • Glenoid (intra-articular)
    • Type 1
      • Indications: >24% involvement of glenoid with humeral subluxation
    • Types 2 – 5
      • Aim for non operative treatment with early ROM
      • ORIF only if there is major incongruity (more than 5 mm articular step) or shoulder instability

Surgical Technique

  • Surgical approach
    • Modified Judet
      • Structures at risk: suprascapular nerve, axillary nerve, circumflex scapular vessels