After spinal stabilization with an implant, patients want to know whether c
arrying loads will endanger their spine and their implant. Therefore, the e
ffect of carrying a weight on the loading of internal spinal fixation devic
es was determined in 10 patients using instrumented, telemeterized internal
fixators. Patients carried a 5 kg dumbbell in one hand as well as up to 20
kg in both hands. Compared to normal standing carrying a weight caused onl
y a slight increase of the fixator loads in all patients. The maximum flexi
on bending moment in the fixators was then lower than during walking. Carry
ing a weight even decreased the axial compression force in the fixators of
the patients with the T11 or T12 vertebra bridged. Patients also raised the
ir arms in anteversion while fielding weights of up to 5 kg with both hands
. This increased the flexion bending moment in the fixators. Only a small p
art of a carried weight is taken over by internal fixators. Carrying a shop
ping bag only slightly increases the risk of pedicle screw breakage, howeve
r, since the spine has to support most of the additional weight, it represe
nts a risk with regard to correction loss and bone sintering. (C) 2000 Else
vier Science Ltd. All rights reserved.