vii
TABLE OF CONTENT
CHAPTER
1
TITLE
PAGE
TITLE
i
DECLARATION
ii
DEDICATION
iii
ACKNOWLEDGEMENTS
iv
ABSTRACT
v
ABSTRAK
vi
TABLE OF CONTENTS
vii
LIST OF TABLES
xi
LIST OF FIGURES
xii
LIST OF ABBREVIATIONS
xiv
INTRODUCTION
1
1.1
Introduction
1
1.1.1 Wrist anatomy
1
1.1.1.1 Bones and joints
1.2
2
Wrist fracture
3
1.2.1 Distal radius fracture
3
1.3
Problem Statement
4
1.4
Objective of Study
5
1.5
Scope of study
5
viii
2
LITERATURE REVIEW
6
2.1
Introduction
6
2.1.1 Classification of intra-articular fracture
6
(1) Intra-articular fracture with displaced
dorsal fragment
(2) Dorsal split with dorsal dislocation
7
(3) palmar split with palmar dislocaton
8
(4) Complex distal radius fractures with
metaphyseal separation
(5) Destruction of the articular surface
2.2
9
9
Different studies on fixation methods
10
2.2.1 Clinical Method
10
2.2.1.1 Non-invasive Techniques
11
2.2.1.1.1 Conservative treatment
11
2.2.1.1.2 External Fixation
12
2.2.1.1.3 Pining
13
2.2.1.2 Open surgery
14
(a) Plates
14
(b) Fragment-specific Fixation
15
(c) Volar locking plates
16
2.2.2 Protocol for surgical treatment
17
2.3 Experimental Method
2.3.1 A novel non-bridging external fixator versus
volar angular stable plating
2.3.2
Comparing volar with dorsal fixation plates on
unstable extra-articular fractures
2.4
7
Computer Simulation Method
18
19
20
22
2.4.1 Biomechanical evaluation of three types of
implants
3
METHODOLOGY
22
27
ix
3.1
Introduction
27
3.2 Mimics Software
27
Step 1: Imported the medical data
28
Step 2: Thresholding
29
Step 3: Segmentation density masks
29
Step 4: Region growing
30
Step 5: 3D Reconstruction
31
3.2.1
32
Constructed of fractured bone
3.3 Implant Design
3.3.1 Introduction of Solidworks Software
35
3.3.2 Designing the implants
36
Simulation of surgical fixation
37
3.5 Introduction to MSC.Marc Software
39
3.4
4
35
3.5.1
Analysing the three fixation methods
40
3.5.2
Applying the loads
41
RESULTS AND DISCUSSION
43
4.1
Introduction
43
4.2 Axial-loads results
44
4.2.1
Displacement
44
4.2.2
Von-Mises Stress
46
4.3 Bending results
4.4
49
4.3.1
Displacement
49
4.3.2
Von-Mises Stress
51
Torsional results
53
4.4.1
Displacement
54
4.4.2
Von-Mises Stress
55
4.5
Overviewing of three three fixation methods
58
4.6
Validation of study
60
4.6.1
Surgical validation
60
4.6.2
Experimental validation
60
x
5
DISCUSSION AND RECOMMENDATION
62
5.1 Discussion
62
5.2
63
Recommendations
REFERENCES
64
xi
LIST OF TABLES
TABLE NO.
TITLE
PAGE
4.1
Maximum displacement (mm) and maximum von
Mises stress (MPa) values of the bone around the
screws of all three groups under the applied loads
47
4.2
Maximum displacement (mm) and maximum von
Mises stress (MPa) values of the bone around the
screws of all three groups under the bending loads
52
4.3
Maximum displacement (mm) and maximum von
Mises stress (MPa) values of the bone around the
screws of all three groups under the torsional
loads
57
xii
TABLE OF FIGURES
FIGURE NO.
TITLE
1.1
Distal and proximal rows of carpal bones
2
2.1
CT-based classification of comminuted intra-articular
7
PAGE
fractures of the distal radius. Type I: intra-articular
fracture with displaced dorso-ulnar fragment
2.2
Type II: dorsal split with dorsal dislocation
8
2.3
Type III: palmar split with palmar dislocation
8
2.4
Type IV: complex distal radius fractures with
9
metaphyseal separation
2.5
Type V: destruction of the articular surface
10
2.6
Schematic drawing of a monolateral external fixator
13
with double ball joints after application to the radial
aspect of the second metacarpal and diaphysis of
the radius: the distal ball joint is centred between
the capitate (C) and lunate bone (L) (intraoperatively
by identification with a bone elevator under image
intensification, lower part of the image) to allow for
mobilisation of the fixator.
xiii
2.7
Typical placement of two T-pins for fixation a distal
14
radius fracture is shown in this posterior-anterior
radiograph. The surgeon has inserted two T-pins from
the radio styloid to stable fracture fixation. The
surgeon has inserted two T-pins from the radio styloid
to stable fracture fixation
2.8
A fragment-specific wrist fixation system
15
2.9
A 31-year-old woman with reverse Barton fracture
16
fixed by volar locking plate
2.1O
The southern Sweden treatment protocol for DRF
18
when selecting different treatments the patient’s age
and demands
2.11
Experimental test with isolated radius placed of
19
custom-made compensator to applied ratio (60-40%)
of the forces transferred to scaphoid and lunata
fragments. (A) Non-bridging external fixation method.
(B) Volar locking fixation method
2.12
(A)The LDRS 2.4-mm intermediate and styloid plates.
21
(B)The LDRS 2.4-mm volar plate.
(C)The LDRS 2.4-mm volar and styloid plates.
(D) The 3.5-mm stainless steel T plate.
2.13
Finite element of different surgical methods. (A) T
shape single volar plate meshing model. (B) Meshing
model of double-palates fixation method. (C) The
modified double-plating (MDP) meshing model
23
xiv
2.14
Loading conditions for model. Axial loading bending
24
and torsion are indicated with arrows. The axial
loading was applied in the middle of the upper radius
surface. The bending force was applied on the volar
side of radius. Torsion is applied on both sides of the
radius representing the external rotating force
2.15
(A) Average total displacement of the fracture site
25
under 50 N axial compression, 2 N-m bending and 2
N-m torsion loads. (B) Maximum displacement of the
fracture site under 50 N axial compression, 2 N-m
bending and 2 N-m torsion loads
2.16
(A) Maximum von Mises stress value for bone in
26
single, DP, and MDP models under 50 N axial
compression, 2 N-m bending and 2 N-m torsional
loads. (B) Maximum von Mises stress value of T plate
in single, DP, and MDP models under 50 N axial
compression, 2 N-m bending and 2 N-m torsional loads
3.1
CT scan image for using in mimic
28
3.2
The top and side views for radius bone that
29
Thresholding by the white color triangular to separate
the radius bone
3.3
The side view of region growing that shown in pink
30
color
3.4
The process of smoothing (A, B and C) to achieve
31
radius bone
3.5
The measured guide lines for cutting (A)
Approximately 10 mm(10.44 mm) from the from
articular surface. (B) About 15° (14.81°) volar wedge
33
xv
3.6
The simulated three segments unstable intra-articular
33
fracture (AO 23-C2.1 fracture). The circle shows the
cut with the curve tool
3.7
(A) The scaphoid segment cleaned meshes.
34
(B) The lunate segment cleaned meshes. (C) The distal
part of the radius cleaned meshes (all segment related
to the cortical parts only)
3.8
(A) Intermediate dorsal LDRS 2.4 mm plate. (B) Volar
37
T-shape LDRS 2.4 mm plate. (C) I-shape Styloid
LDRS 2.4 mm plate
3.9
Fixed all the meshes around the screws on both cortical
38
and cancellous parts of bone
3.1O
Fixed all the interfaced meshing part between all
39
cancellous and cortical and screws. (The red parts
show the interfaced parts)
3.11
Defined the young’s modulus, Poisson’s ratio and
40
contact parts for each part (that showed in collared
parts)
3.12
Axial loading that applied on scaphoid and lunate
42
regions base on each percentage and tilt angle, bending
load that exerted on simulated bone on volar side of the
radius and the torsion applied of the radius part of the
bone
4.1
Model rigidity under axial compressive load
45
4.2
Maximum displacement of the bone around the screws
45
under the 10 N, 25 N, 50N, and 100 N loads
xvi
4.3
Maximum von-Mises stress under the 10 N, 25 N, 50N
46
and 100 N loads
4.4
Maximum von-Mises stress of the bone around the
47
screws under the 10 N, 25 N, 50N, and 100 N loads
4.5
The contour plots of displacement for three groups of
48
fixations under applied 100 N axial load
4.6
The mean maximum displacement under bending loads
50
(1 N-m, 1.5 N-m, 2 N-m)
4.7
The maximum displacement around the screws under
50
applied bending loads (1 N-m, 1.5 N-m, 2 N-m)
4.8
The maximum von-Mises stress under applied bending
51
loads (1 N-m, 1.5 N-m, 2 N-m)
4.9
The maximum von-Mises stress around the screws
51
under applied bending loads (1 N-m, 1.5 N-m and
2 N-m)
4.1O
The contour plots of displacement for three groups of
53
fixations under applied 2 N bending load
4.11
The mean maximum displacement under torsion loads
54
(1.5 N-m, 2 N-m, 2.5 N-m)
4.12
The maximum displacement around the screws under
55
applied torsion loads (1.5 N-m, 2 N-m, 2.5 N-m)
4.13
The maximum von-Mises stress under applied bending
56
loads (1.5 N-m, 2 N-m and 2.5 N-m)
4.14
The maximum von Mises stress around the screws
under applied torsion loads (1.5 N-m, 2 N-m and
2.5 N-m)
56
xvii
4.15
The contour plots of displacement for three groups of
58
fixations under applied 2 N torsional load
4.16
(A) Average total displacement of the fracture site
under the 100 N axial compression, 2 N-m bending
and 2.5 N-m torsional loads. The total displacement
was averaged from the displacement of the nodes on
the fracture site. (B) Maximum von Mises stress value
for bone in three groups of fixations under 100 N
compression load, 2 N-m bending and 2.5 N-m
torsional loads
59
xviii
LIST OF ABBREVIATIONS
2D
-
Two Dimensional
3D
-
Three Dimensional
CAD
-
Computer-Aided design
CT
-
Computerized Tomography
DRFs
-
Distal Radius Fractures
DP
-
Double Plating
FEA
-
Finite Element Analysis
HU
-
Hounsfield Scale
LCPS
-
Locking Compression Plate System
LCPS
-
Locking Compression Plate System
LDRS
-
Locking Distal Radius System
MDP
-
Modified Double Plating
MRI
-
Magnetic Resonance Imager