Monday, June 16, 2014

The remodelling potential of the proximal humerus in the pediatric population

The following case is a 4 year old female who fell off a trampoline. Presented with an angulated proximal humerus fracture. She was treated with a sling. At one year followup the fracture is completely remodelled and there is no visible angulation or fracture line. 

There is almost never the need for surgery in this patient population for this type of injury. However, in patients greater than 12 years of age a careful assessment of the degree of angulation and displacement needs to be done .
The indication for surgery are for:
  • severly displaced fractures in adolescents 
    • <50% apposition or >45° angulation
It is important to remember that the proximal humerus in the pediatric population has:
  • Three centers of ossification
    • humeral head appears at 6 mos
    • greater tuberosity appears at 3 yrs
    • lesser tuberosity appears at 5 yrs
  • Secondary ossification centers unite together at age 6-7
    • Proximal humerus physis closes at 14-17 in girls, 16-18 in boys
    • 80% of humerus growth comes from the proximal physis
      • highest proximal:distal ratio difference (femur is second with 30:70 proximal:distal ratio)