Treatment of Physeal Fractures Flashcards
what is the epiphysis?
end of a long bone
arises as secondary center of ossification
how does longitudinal bone growth occur?
endochondral ossification
where is the reserve zone?
adjacent to the epiphysis
what is the physeal blood supply?
epiphyseal artery
metaphyseal artery
disruption of the __________________ leads to necrosis of the germinal cells and permanent cessation of growth
epiphyseal blood supply
where does a stress riser exist within the physis?
within hypertrophic zone
what does a salter-harris type VI result in?
angular or rotational deformity
what is a salter-harris type I?
fracture or separation through the hypertrophic zone
what is a salter-harris type II?
fracture or separation through a portion of the hypertrophic zone and the metaphysis
what is a salter-harris type V?
crushing injury of the physis
what is the most common site of a salter-harris type V?
distal ulna
does fixation that bridges the physis prevent bone growth?
yes
when do the physes of the femur close?
by 6-9 months
when is the prognosis guarded?
in animals with considerable growth potential
what is the metaphysis?
wider shaft of the bone adjacent to the physis
what is the physis divided into?
four zones
what is the proliferating zone like?
cells divide in linear fashion
germinal cells are adjacent to the epiphysis
what is the hypertrophic zone like?
broad flat cells
8x increase in cell volume
decrease in extracellular matrix
what is the most common site of salter-harris type I?
femoral capital physis
what is the most common site of salter-harris type II?
distal femur
what is a salter-harris type IV?
fracture or separation through a portion of the hypertrophic zone, metaphysis, and epiphysis
what does salter-harris type V result in?
necrosis of the resting layer of cartilage cells and therefore cessation of bone growth
where do smooth pins damage the physis?
at the point at which they traverse
utilize small diameter pins
when do the physes of the humerus close?
proximal 10-12 months
distal 6-7 months
what predisposes the distal ulnar physis to salter-harris type V?
conical shape of physis
what does premature closure of the distal ulnar physis result in?
shortening of ulna
shortening of radius
cranial bowing
valgus
external rotation
elbow and carpal incongruity
