Di. Bylski-austrow et al., Growth plate forces in the adolescent human knee: A radiographic and mechanical study of epiphyseal staples, J PED ORTH, 21(6), 2001, pp. 817-823
The purpose of this study was to quantify the forces produced by the growth
plates of the adolescent human proximal tibia and distal femur. The postop
erative deformations of staples used to treat genu valgum. were correlated
with similar staple deformations produced by mechanical testing. Staple def
ormation was measured in sequential radiographs of 35 knees in 20 patients.
Mechanical tests were performed on new staples to determine the force nece
ssary to bend the staples to the observed displacements. Based on deformati
on at final examination, the static equivalent loads exerted at the joint c
enterline by the growth plates of the proximal tibia and distal femur were
0.5 kN per physis. The estimated corresponding stress was 1 MPa. These resu
lts indicated that successful lower limb hemiepiphysiodesis suppressed a lo
ngitudinally directed, centrally applied compressive force on the order of
body weight.