Pediatrics Case 13 Background

Salter-Harris Type II fracture of the middle phalanx.

Children commonly sustain injuries of the physis because the cartilaginous growth zone that bridges the physis is weaker than bones and ligaments. The growth plate is the weakest link of the pediatric skeleton.  Kids are more likely to fracture through the growth plate than to sprain around it.  Be careful diagnosing kids “with just a sprain.”

Salter-Harris classification is used to describe five patterns of physeal injuries. This classification system is helpful because it is a simple way for clinicians to risk stratify these injuries, as lower numbers tend to be less severe and have lower risk of growth-related abnormalities and other feared outcomes. Blood supply to the physis comes from the epiphysis. So fractures that spare the epiphysis, if properly aligned/reduced, are more likely to resume normal bone growth and not develop bone length discrepancy.

Salter Harris II fractures extend through the physis and the metaphysis.  These are the most common type of growth plate fracture (75%).

A common mnemonic used to remember types of Salter-Harris Fractures is the word “SALTER”, with each letter standing for and describing a different type of fracture and the fracture’s relation to the physis for most long bones.

S: “Slipped/Straight-through” physis only injury (Type I)

A: “Above”(proximal to physis) (Type II)

L: “Lower” (distal to physis) (Type III)

T: “Through/Transverse” (through metaphysis and epiphysis) (Type IV)

ER: “Erasure/Rammed/Ruined” (crushed physis) (Type V)