Salter-Harris fractures
Background
S 1- Slipped (thru epiphysis)
A 2- Above (epiphysis c metaphysis fx)
L 3- Lower (thru epiphysis)
T 4- Through (epi and meta)
R 5- Rammed (growth plate crushed)
(*reference joint is below*)
- most significant diff btwn adult and child bones is presenece of physis/ growth plate
- is composed of proliferating cartilage cells and lacks inherent strength and therfore easily damaged.
- injury can happen at any age but most common during period of rapid growth
- if missed- prematume closure and bone growth arrest
- most common after age 10
- more in boys- more active and later skeletal maturity than girls
- funtion of physis is for rapid longitudinal bone growth
- distal radius most common site
- ligaments stronger than bones in kids- more likely to fx than sprain
- repetitive stress injury can also cause it
- suspect if point tenderness over physis and neg xray
Physis zones- epiphysis to metaphys. Blood supply from epiphysis
1- resting cells
2- proliferating cells
3- hypertophic/ maturing cells- weakest link were fx occurs
4- zone of provisional calcification
- higher the salter #, the more physeal arrest and joint incongruity because of injury to vascular supply to physis
Types
Type 1- slip
- slip through epiphysis
- mostly in infants and todlers
- by shearing torsion avulsion
- fx thru hypertrophic zone with growing cells remaining on the epiphysis in continuity with blood supply
- no osseous fx
- good prognosis
Type 2- above
- fx thru\above metaphysis. fx thru hypertrophic zone of physis and then above thru metaphysis.
- most common type of fx
- segment of metaphyseal bone called Thurston Holland fragment
Type 3- below
- intraarticular fx
- relatively rare
- the greater displacement, greater chance of vasc supply compromise and greater chance of growth disturbance
Type 4- both
- starts at articular surface thru epiphysis thru physisi thru metaphys
- mostly at distal humerus
Type 5- crush
- most rare type
- highest chance of growth arrest
- compression crushes cells of zone of reserve and proliferation
- minimal or no displacement of epiphysis
- usually at knee or ankle by severe adduction abductn
- usually dx in retrospect once bone growth abnormality already seen
Diagnosis
X rays
- can have acute fx ang neg x ray- look for point tenderness over physis
- type 2-3-4 can see on xray
- type 1 - 5 can be occult
- type 5 may have effusion
- can also use stress radiography
Treatment
- type 1 2- splint
- type 3-4- surg, probably ORIF
- type 5- ortho, casting and nonwt bearing