Many innovative experiments are designed to answ
er research questions about hip
biomechanics, however many fail to define a coordinate system. This makes comparisons
between studies unreliable and is an unnecessary hurdle in extrapolating experimental
results to clinical reality. The aim of this study
was to present a specimen mounting protocol
which aligns and registers hip specimens in the International Society of Biomechanics (ISB)
coordinate system, which is defined by bony landmarks that are identified by palpation of the
patient’s body. This wou
ld enable direct comparison between experimental testing and
clinical gait analysis or radiographic studies. To represent the intact hip, four intact synthetic
full
-
pelves with 8 full
-
length articulating femora were assembled and digitised to define the
IS
B coordinate system. Using our proposed protocol, pelvis specimens were bisected into
left and right hemi
-
pelves and femora transected at the mid
-
shaft, and then mounted in bone
pots to represent a typical experimental setup. Anatomical landmarks were re
-
digitised
relative to mechanical features of the bone pots and the misalignment was calculated. The
mean misalignment was found to be less than 1.5° flexion/extension, ab/adduction and
internal/external rotation for both the pelves and femora; this equate
s to less than 2.5
% of a
normal range of hip motion. The proposed specimen mounting protocol provides a simple
method to align in vitro hip specimens in the ISB coordinate system which enables improved
comparison between laboratory testing and clinical s
tudies. Engineering drawings are
provided to allow others to replicate the simple fixtures used in the protocol.