BACKGROUND: At present, the prosthesis is made by three steps: taking, trimming and
shaping. Because the process of trimming is manual, it is closely related to
the experience and technology of clinical technicians. If the prosthesis is not
beautiful, it is difficult to make full contact between the receiving cavity
and the residual limb.
OBJECTIVE: To collect MRI data of thigh in
healthy volunteers, evaluate the anatomical symmetry of thigh amputation range
(10-25 cm above knee joint
space), and establish MRI data as a database so as to provide reference data
for patients with lower limb amputation to match the appropriate prosthesis after
METHODS: Totally 40 healthy volunteers were
recruited and basic information was collected, including age, height, weight,
the circumference of the knee, the circumference of the knee at 5 cm, the
circumference of the knee at 10 cm, and the circumference of the knee at 15 cm.
All volunteers signed the informed consent. This study was approved by the
Hospital Ethics Committee. Three-dimensional reconstruction was carried out in
thigh amputation range. Taking the surface area and volume of the model as
parameters, the thighs of each volunteer were anatomically measured.
Three-dimensional reverse engineering software was used to analyze the
three-dimensional deviation of the measurement results so as to conduct
quantification and visualization of the thigh symmetry.
RESULTS AND CONCLUSION: (1) Self symmetric
analysis: Regarding the surface area, the maximal percent difference between
the left and right thigh amputation was no more than 0.56% (P=0.109). Regarding the volume, the
maximal percent difference between the left and right thigh amputation was no
more than 1.19% (P=0.182). Results of
the three-dimensional deviation analyses showed that the maximal mean negative
deviation was -1.47
mm, while the maximal mean positive deviation was 1.14 mm. Moreover, the
three-dimensional deviation distribution of 40 subjects was within 2 mm
(78.02%), between 2.1 and 3.0 mm (20.97%), and more than 3 mm (1.01%). (2)
Allogeneic symmetric analysis: Results of the three-dimensional deviation
analyses showed that the maximal mean negative deviation was -1.97 mm, while the
maximal mean positive deviation was 1.89 mm. (3) The results confirmed that
adult bilateral thigh amputation range has a high degree of anatomical
symmetry. When differences between two adults’ right thighs are no more than 2
cm in the circumference of the knee, the circumference of the knee at 5 cm, the
circumference of the knee at 10 cm, and the circumference of the knee at 15 cm,
their surface profiles of thigh amputation ranges are considered to be highly
similar, but are not associated with gender, height and weight.