A Salter–Harris fracture is a fracture that involves the epiphyseal plate or growth plate of a bone. It is a common injury found in children, occurring in 15% of childhood long bone fractures.
There are nine types of Salter–Harris fractures; types I to V as described by Robert B Salter and W Robert Harris in 1963, and the rarer types VI to IX which have been added subsequently:
Type I – transverse fracture through the growth plate (also referred to as the "physis"): 6% incidence
Type II – A fracture through the growth plate and the metaphysis, sparing the epiphysis: 75% incidence, takes approximately 2–3 weeks to heal.
Type III – A fracture through growth plate and epiphysis, sparing the metaphysis: 8% incidence
Type IV – A fracture through all three elements of the bone, the growth plate, metaphysis, and epiphysis: 10% incidence
Type V – A compression fracture of the growth plate (resulting in a decrease in the perceived space between the epiphysis and metaphysis on x-ray): 1% incidence
Type VI – Injury to the peripheral portion of the physis and a resultant bony bridge formation which may produce an angular deformity (added in 1969 by Mercer Rang)
Type VII – Isolated injury of the epiphyseal plate (VII–IX added in 1982 by JA Ogden)
Type VIII – Isolated injury of the metaphysis with possible impairment of endochondral ossification
Type IX – Injury of the periosteum which may impair intramembranous ossification
The mnemonic "SALTER" can be used to help remember the first five types. This mnemonic requires the reader to imagine the bones as long bones, with the epiphyses at the base.
I – S = Slip (separated or straight across). Fracture of the cartilage of the physis (growth plate)
II – A = Above. The fracture lies above the physis, or Away from the joint.
III – L = Lower. The fracture is below the physis in the epiphysis.
IV – TE = Through Everything. The fracture is through the metaphysis, physis, and epiphysis.
V – R = Rammed (crushed). The physis has been crushed.
(alternatively SALTER can be used for the first 6 types – as above but adding Type V: 'E' for Everything or Epiphysis and Type VI:'R' for Ring)
