Proximal Humeral Fractures
Incidence
- Around 4-5% of all fractures
- 85% have minimal displacement – Neer group I
Classification
Neer classification
- Classification is based on the four-part anatomy of the proximal humerus
- humeral head
- lesser tuberosity
- greater tuberosity
- proximal humeral shaft
- Criterion for displacement
- greater than 1 cm of separation of part
- angulation of 45 degrees.
- Neer's terminology of four-segment classification of displaced fractures and fracture-dislocations relates pattern of displacement (two-part, three-part, or four-part) and key segment displaced.
- In each two-part pattern, segment named is one displaced.
- Two-part surgical neck fractures
- impacted (A)
- unimpacted (B)
- comminuted (C).
- 3 Part
- All three-part patterns have displacement of shaft segment
- displaced tuberosity identifies type of three-part fracture.
- 4 part
- In four-part pattern, all segments are displaced.
- Fracture-dislocations
- identified by anterior or posterior position of articular segment.
- Large articular surface defects require separate recognition
- Displaced three-part and four-part fractures
- markedly alter the articular congruity of the glenohumeral joint
- highest likelihood of disrupting the major blood supply to the proximal humerus
- Osteonecrosis is most likely after displaced four-part fractures.
- Significant intra & inter-observer variability
Investigations
Xrays
- AP, Lateral
CT
- defining head splitting fractures
MRI
- assess for related cuff or labral lesions
- labral lesions are common, occurring in 56% of patients with fracture dislocations.
Treatment
Treatment of displaced fractures
Decision based on:
- Age & activity level of patient
- Quality of bone
- Type of fracture
- Presence of other injuries
- Humeral head salvage should be attempted in young patients with good bone stock
- In older patients primary arthroplasty may be performed
Displaced surgical neck fractures
- In adults these should be stabilized after closed reduction with terminally threaded K wires
Tuberosity fractures
- If these are displaced more than 5mm they should be openly reduced
- greater tuberosity via deltoid splitting approach
- lesser tuberosity via deltopectoral approach
- If GT fractures are not fixed they may cause impingement against acromion
4 part fractures
- In young adults, ORIF associated with AVN in around 10%
- In patients treated with hemiarthroplasty, there is usually good pain relief but poor ROM.
- Functional outcomes are better after early hemiarthroplasty (within 4 weeks of fracture) than after late arthroplasty following unsuccessful non-operative treatment.