What are the guidelines for managing humerus head fractures?

Management of Humeral Head Fractures

Critical Note on Available Evidence

The provided evidence exclusively addresses pediatric supracondylar humerus fractures, NOT humeral head (proximal humerus) fractures in adults. These are entirely different injuries with different anatomical locations, mechanisms, patient populations, and treatment paradigms. I will provide guidance based on the limited adult proximal humerus fracture research available and general orthopedic principles.

Treatment Algorithm by Fracture Displacement and Patient Factors

Nondisplaced or Minimally Displaced Fractures

Conservative management with immobilization achieves good functional outcomes for nondisplaced humeral head fractures. 1

• Immobilize in a sling or shoulder immobilizer
• Early passive range of motion exercises as pain allows
• Good functional results are consistently achieved with non-operative treatment 1

Displaced Fractures: Decision Framework

The treatment choice for displaced proximal humerus fractures depends critically on fracture complexity, bone quality, patient age, and pre-existing shoulder pathology. 2

Two-Part and Three-Part Fractures

Most surgeons (69% for 2-part, 53% for 3-part) prefer open reduction and internal fixation (ORIF) with locking plates for displaced 2-part and 3-part fractures. 2

• ORIF is preferred in younger patients with good bone quality 2
• Use minimal invasive surgical techniques when possible 1
• Early active motion rehabilitation after locking plate fixation is not inferior to restrictive protocols and may be preferred 3
  • No immobilization restrictions needed with modern angular stable implants 3
  • Avoid heavy lifting and blunt force for 3 months 3
  • Achieves equivalent functional outcomes (Constant Score ~80 points, relative CS 89.8%) at 24 months 3

Four-Part Fractures

Early adequate open reduction and internal fixation is the treatment of choice for displaced four-part fractures, rather than primary prosthetic replacement. 4

• Most humeral heads develop avascular necrosis but undergo rapid revascularization through creeping substitution 4
• Subchondral collapse is uncommon even when AVN occurs 4
• Primary prosthetic replacement should be reserved for specific indications (see below) 1, 5

Indications for Arthroplasty Over ORIF

Switch from ORIF to arthroplasty when the following factors are present: 2

• Intra-articular fracture pattern (82% of surgeons) 2
• Poor bone quality/severe osteoporosis (76%) 2
• Advanced age >50 years with head-split fracture (90%) 2
• Pre-existing rotator cuff dysfunction (70%) 2

Reverse Shoulder Arthroplasty (RSA) Preferred Over Hemiarthroplasty

RSA is strongly preferred (94%) for: 2

• Head-split fracture in elderly patients 2
• Pre-existing rotator cuff tear (84%) 2
• Pre-existing glenohumeral arthritis with intact cuff (75%) 2
• Complex fractures in elderly patients with poor bone quality 2

Hemiarthroplasty (HA) Considerations

HA is preferred by 43% of shoulder surgeons for young patients with head-split fractures (versus 54% preferring ORIF), showing significant practice variation 2

• Consider HA in young patients with limited humeral head subchondral bone 2

Special Populations

Low-Functioning Elderly Patients

Practice varies significantly between trauma and shoulder surgeons: 2

• Trauma surgeons prefer nonoperative management (84-86%) for significantly displaced or nonreconstructable injuries 2
• Shoulder surgeons split between RSA (44-46%) and nonoperative treatment (54%) 2
• In multimorbid elderly patients, always consider conservative treatment as a viable option 1

Young Patients with Fracture-Dislocation

ORIF is strongly preferred (94%) for young patients with fracture-dislocation 2

Critical Technical Considerations

Fracture Pattern Recognition

Differentiate between avulsion and depression fractures, as this determines implant selection: 5

• Avulsion fractures: Varus tendency of humeral head 5
• Depression fractures: Valgus position of head fragment 5

Imaging Requirements

• Mandatory x-rays from two levels 5
• 3-D CT scan is very useful for understanding complex fracture character 5
• Assess: fragment number/position, periosteal integrity, muscle forces acting on fragments 5

Implant Selection

Choose between rigid and semi-rigid implants based on fracture type and bone quality: 5

• Semi-rigid implants indicated for: Simple fractures and poor bone quality 5
• Rigid implants indicated for: Complex fractures with good bone quality 5

Displacement Tolerance by Location

Acceptable displacement varies by anatomic location: 5

• Subacromial space: Even small incongruities impair gliding mechanism—minimal displacement acceptable 5
• Head-shaft interface: Larger displacements can be accepted 5

Common Pitfalls

• Choosing primary prosthetic replacement for four-part fractures when ORIF would preserve the native head 4
• Overly restrictive postoperative protocols that delay rehabilitation unnecessarily 3
• Failing to obtain 3-D CT for complex fracture patterns 5
• Not considering nonoperative management in elderly multimorbid patients 1
• Ignoring pre-existing rotator cuff pathology when planning reconstruction 2