a novel computer-aided approach for parametric ...a fracture gap was created 6cm above the knee...

$: A Novel Computer-Aided Approach for Parametric ...A fracture gap was created 6cm above the knee joint, and the fractured segments were translated and rotated 3D fractured bone model$
Research ArticleA Novel Computer-Aided Approach for Parametric Investigationof Custom Design of Fracture Fixation Plates

Xiaozhong Chen12 Kunjin He13 and Zhengming Chen13

1College of Internet of Things Engineering Hohai University Changzhou China2School of Intelligent Equipment and Information Engineering Changzhou Vocational Institute of Engineering Jiangsu China3Changzhou City Key Lab of Orthopedic Implants Digital Technology Changzhou China

Correspondence should be addressed to Xiaozhong Chen chenxiaozhonghh163com and Kunjin He kjinhe163com

Received 31 October 2016 Accepted 13 December 2016 Published 19 January 2017

Academic Editor Kaan Yetilmezsoy

Copyright copy 2017 Xiaozhong Chen et al This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

The present study proposes an integrated computer-aided approach combining femur surface modeling fracture evidence recoverplate creation and plate modification in order to conduct a parametric investigation of the design of custom plate for a specificpatient The study allows for improving the design efficiency of specific plates on the patientsrsquo femur parameters and the fractureinformation Furthermore the present approach will lead to exploration of plate modification and optimization The three-dimensional (3D) surface model of a detailed femur and the corresponding fixation plate were represented with high-level featureparameters and the shape of the specific plate was recursively modified in order to obtain the optimal plate for a specific patientThe proposed approachwas tested and verified on a case study and it could be helpful for orthopedic surgeons to design andmodifythe plate in order to fit the specific femur anatomy and the fracture information

1 Introduction

Distal femur fractures consist of around 3 of all femurfractures and are results of the high-energy trauma to youngpatients and the low-energy trauma to older populationwith osteoporosis bones [1 2] Although internal fixationtechnologies are used in orthopedic trauma surgery thesefemoral fractures are difficult to treat for the comminutedfracture segments In the past decades the development ofdistal femur implants has facilitated the operative treatmentof such fractures [3] Compared to other implants such asintramedullary devices plates are more widely applied toclinical treatments for some reasons [4] However in somepractical cases additional remodelingwas frequently taken toproximate plates to fit the specific anatomy and the patientrsquosfracture information Nevertheless these modifications willlead to the increased failure rate of surgical treatments [5]Plates precontoured based on specific femurs may promotethe anatomic recovery and achieve fracture healing [6]Therefore the development of patient-specific plates has been

regarded as a research trend of next-generation medicaldevices [7]

Some investigations [8ndash10] have been focused upon theplate development recently In the work [9] the 3D solidmodel of femoral fracture reconstructed from ComputedTomography (CT) scan data was utilized to create the plateShen and coworkers [10] developed dissection plates fordifferent patients based on CT slices In above two studiestheoretical reference and operation reference models wereproposed for the orthopedic surgery and fracture fixationassembling However little attention has been devoted toconsider the efficiency of plate development In recent pub-lished studies the custom plate design was achieved withvarious processes that is reduction of fractured bonescreation of fixation plates and modification and fractureplates [11] However most researchers have neglected to findthe relationship between various processes to improve designefficiency owning to different discrete procedures in theoverall development Thus how to construct and edit plate

HindawiComputational and Mathematical Methods in MedicineVolume 2017 Article ID 7372496 7 pageshttpsdoiorg10115520177372496

2 Computational and Mathematical Methods in Medicine

models accurately and conveniently is very significant and itis a challenge to the development of a specific patient plate

Previously the authors proposed a parametric methodto construct a surface model of a patientrsquos femur based onsurface feature parameterization [12] It was found that thesurface model could be accurately constructed and modifiedaccording to the hierarchical feature parameters of a patientrsquosfemur [13] In this study a novel parametric method isproposed to develop a patient-specific plate based on thepatientrsquos information by using feature parameterization Theparametric models of femur plates can be quickly createdbased on parameter maps between the femur and the platemodified with a few semantic parameters and optimized byrecursively modifying plate shapes based on feature parame-ters To achieve this purpose three major requirements haveto be satisfied

(i) The plate should be designed according to the femuranatomy and fracture information (such as fracturetype and degree) of specific patients

(ii) The plate should be edited andmodified convenientlyby the physicians to match the morphology of aspecific patient bone

(iii) The creation and modification of the plate have tobe done within 24 hours after the injury to voidcomplications

Although there are lots of meaningful data in any frac-tured femur models these data are hard to measure and notdefined as parameters so that they are difficult to be used inthe representation and design of plates The research workreported in this paper is motivated by the above observationCombiningwith the thought of feature parameterization [14]themain contribution of this paper lies in the development ofa rapid method for the plate design from the fractured femurof a specific patient Our proposed method can support thedesign user to customize and optimize femur plates accordingto the information of specific patient

2 Materials and Methods

In this study an intact right femur of a young femalevolunteer without any disease or trauma was selected at ourresearch center

The complete framework for designing the custom platebased on the existing fractured femur of a specific patientis described in Figure 1 The major steps will be explainedfurther in the following parts of this section

21 Construction of the Fractured Bone Model To obtain 2Dscan images of the femur 64-slice CT (MSCT Aquilion 64Toshiba Zoetermeer Netherlands) was utilized After CTscanning of the selected femur by using the medical process-ing software MIMICS the intact 3D femur mesh model wascreated with four stages such as image preprocessing imagesegmentation surface extraction and mesh simplification[15]

A fracture gap was created 6 cm above the knee jointand the fractured segments were translated and rotated

3D fractured bone model

Specific patientrsquos CT

3D Construction

Yes

Reduced fractured model

Initial custom fracture plate

Custom fracture plate

Match

Model alignment

Constraint creation

Fractured bone of patient

CT scan

No

Figure 1 The flowchart of the design of a custom fracture plate

6 cm

Figure 2 The simulated 3D fractured femur mesh model with a33A1-C3 type fracture

to simulate a 33A1-C3 type fracture (AO-Classification) asshown in Figure 2

22 Reduction of Fractured Bone Segments In many femoralfractures the segments are usually comminuted and dis-located and the 3D fractured model cannot describe theaccurate morphologies of a normal femur Therefore the 3Dreconstruction of the intact femur representing the normalsurface shape of a specific patient especially of the fracturedsite is very useful for surgeons to select an optimal implantand treat the fracture

With the consideration of the significance of femur shapesin the plate design the authors focused on the surface modelof a intact femur and the surface model with the fractureevidences was constructed with the following step

Computational and Mathematical Methods in Medicine 3

Hr

(a) (b)

Fracture curves

(c)

Figure 3 The detailed steps of constructing the surface model of restored fractured femur (a) Parameters measurement (b) surface modeconstruction and (c) fracture evidence restoration

Step 1 A few of valid femur parameters were extracted fromthe fractured solid femur constructed in Section 21 as shownin Figure 3(a)

Step 2 The surface model of the fractured femur was con-structed according to the patientrsquos femur parameters basedon the parameter constraints to represent the normal shapeof the femur as shown in Figure 3(b)

Step 3 The constructed surface model was validated andmodified based on femur parameters

Step 4 The fractured femur model with fracture curveswhich were used to represent major fracture evidences asshown in Figure 3(c) was extracted by projecting the mainboundary curves onto the surface model

23 Construction of the Initial Plate Model Because theconstructed femur model in the above subsection maydescribe anatomic shapes of the detailed femur and the maininformation of the fracture the plate bottom surface betweenthe bone and the femur was selected with a suitable contourbased on the fracture from the above surface model and itwas extracted with various distances so that the plate volumemodel was constructed Finally the feature parameters weredefined to represent the plate model as described in Figure 4The algorithm for constructing and parameterizing the platewas expounded as follows

Step 1 A closed curve on the lateral surface was created fromthe orthographic projection of the contour sketch and thesurface of the femur was cut with the projection and cutoperation to obtain the plate bottom surface as shown inFigure 4(a)

Step 2 The bottom surface of the plate was parameterizationto represent the detailed shape with semantic parameterssuch as length parameters and width parameters as shown inFigure 4(b)

Step 3 The bottom surface was extruded outwards withnonisometric distances to obtain a volumemodel of the plateand volume features (that is thickness) of the model werepresented with semantic parameters as shown in Figure 4(c)to create the model of the specific plate

Step 4 Based on the approximate linear map relationsbetween femur parameters and plate parameters proposed inour previous study [11] as described in Figure 5 the detailedparameter values can be atomically evaluated According tothe map relationship between feature points of the femursurface and the plate surface as shown in Figure 6 the shapeand the thickness of specific plate were adjusted to matchthe femur anatomy of a specific patient and the fractureinformation as shown in Figure 7

In this study the femur model with a 33A1-C3 type frac-ture was firstly measured to obtain valid feature parametersof femur that is the head radius Hr (21061mm) and thenthe SFMF was quickly constructed for the plate design [12]Based on the map relations between femur parameters andplate parameters the specific plate was constructed to matchthe femur anatomy of a specific patient and the detailedparameter values were listed in Table 1

24 Shape Modification of the Plate The plate was dividedinto three parts for example the proximal fractured site andthe distal Based on the feature parameters of the plate theinitial plate atomically created with the femur parameters can


Plate surface

(a)

Pw4

Pw3

Pw2

Pw1

Pl1

Pl2

Pl3

(b)

Pt1

Pt2

Pt3

Pt4

(c)

Figure 4 Parameterization of the distal femur plate for a specific fracture (a) Contour projection and surface generation (b) parameterizationof the plate surface (c) parameterization of the volume model

Model parameters

Contour parameters

Femur

Plate Solid parameters

Feature parametersConstraint

Mapping 1205831 Mapping 1205832

Figure 5 Parameter map relations between the femur and plate 1205831

is a map between the model and contour parameters whereas 1205832 isa map between the femur feature and solid parameters

Table 1 The parameter values of the init plate for a specific femuranatomy (mm)

Parameters Values1198751198971 13211198751198972 6711198751198973 6501198751199081 3431198751199082 1701198751199083 1301198751199084 130119875ℎ1 30119875ℎ2 30119875ℎ3

30119875ℎ4 30

be efficiently edited and modified As shown in Figure 8 thethickness values of each part were ranged from 3 to 4mm 3to 5mm and 2 to 3mm respectively

In the first instance that is the init plate constructed inSection 23 3mm was assigned to all parameters in variousparts as shown in Figure 8(a) In the second instance thethickness of the distal was reduced from 3 to 2mm becausethe attached area of that part was larger than any one of theothers as shown in Figure 8(b) while the width value of

Table 2 The width values of two plates (the init and final) (mm)

Parameters 1198751199081 1198751199082 1198751199083 1198751199084

Init 130 130 170 342Final 170 170 225 343

the fractured site was increased from 17mm to 218mm toimprove the strength of the plate In the third instance thatis the final plate the parameter values of the fractured sitewere increased as shown in Figure 8(c)

The init and final instances of the distal plate with eachwidth parameter shown in Table 2 were used to evaluatethe mechanical stress in the fractured model fixated withplates and screws The maximum von Misesrsquo stresses for thesame fractured model were obtained The parameterizationmodification resulted in a remarkable reduction ofmaximumvon Misesrsquo stress from the init to the final so that the fatiguelife of the final plate can be improved

In this study the init plate exhibited significantly lowermaximum von Misesrsquo stress than the that reported in theprevious work [16] and the stress of the modified plate wassignificantly reduced compared to the one of the init plate

What is more the mechanical environment of the plate isrelated to various factors of specific patients such as femuranatomy bone quality weight fracture type and complexityThe parameterization method can help nonexpert users todefine and modify any values of the factors to effectivelyconstruct and optimize the plate according to the specificanatomy and fracture of patients

3 Discussions

Designing plates that match the morphology of a specificpatient bone is a great advancement in place of usingcommercially available plates which are designed based onaverage anthropometric data Custom made total knees andtotal hips (joint arthroplasty and most often in relation to


Pt1

Pt2Pt3

Pt4 Pt5 Pt6

Pt7 Pt8Pt9

Pt10Pt11

Pt12

Pt13Pt14 Pt15

Pt16

Pt17

Pt18Pt19

MDC

MDF

P998400t1

P998400t2 P998400

t3

P998400t4

P998400t5

P998400t6

P998400t7

P998400t8

P998400t9

P998400t10

P998400t11 P998400

t12

P998400t13

P998400t14 P998400

t15

P998400t16

P998400t17 P998400

t18

P998400t19

Figure 6 Map relations between the feature parameters of the femur surface and the plate surface

the knee) are available and used frequently But designingand producing these implants takes time to produce andmanufacture While the physician may have the time to waitfor the design of custom plates if the case is elective (ie totalknee or deficiency in the acetabulum) in the case of a fractureor fracture dislocation the physician does not have time towait Most fracture cases should be done 24 to 48 hours afterinjury to avoid complications especially long bone fractures

In the published studies [8 10] although the existingcontours of commercial plates can be selected and developedas shape templates the existing plate is hard to reuse for thefreeform complexity of attached surfaces of plates Thereforeit needs to start from scratch in a new development evenin case of the similar type of shapes for other patients withdifferent sizes Feature parameterization was an efficient wayto represent and modify the complex shape of the platesWhat is more building up the linear maps between plateparameters and femur parameters can achieve the rapiddevelopment of origin plates based on a few femur parametersof specific patients

The patient-specific plate which was designed in accor-dance with anatomical morphology and physiological radianon the femur can well attach to the bone without additionalshaping as well as can be effective in maintaining fine

relations between anatomic reduction of fracture fragmentsHowever it is a known fact that it is hard to accuratelyrepresent the anatomy shape of the fractured site especiallyin commented fractures because of the cancellous boneof the condyle Fortunately the SFMF created by statisticalshape analysis can shield the differences and can describe thetypical femoral anatomy of certain population Therefore itsmorphology can be used for developing and manufacturingof implants for a specific group [17]

In addition to improve the mechanical strength of theplate the holes near to the fracture gap should to be removed[5] What is more the fracture lengths result in the differentstress of the fixation system [18] Therefore the developmentof plates must match the fracture type and complex Besidesmaterial thickness is a very important factor in the platedesign [16] the thickness and the width parameters espe-cially in the fracture site have significant meanings in theplate development How to edit conveniently the shape of theplate is a challenge in the development of specified plates Byadjusting the values of the high-level parameters of originplates such as the width thickness and length the finaloptimized plate can be constructed and modified effectively

There are several limitations to the study as the results areobtained solely based on FEA Firstly the two constituents


Figure 7 The specific plate model atomically constructed based on the parameter maps and femur parameters

proximal distalfracture site

(a)

(b)

(c)

Init plate

Final plate

Modified plate2mm

2mm

3mm

3mm 3mm

3mm3mm

3mm

4mm

4mm 4mm5mm

Figure 8Three instances with various values of thickness parameter (a) (b) and (c) represent the init modified and final plate respectively

of the femur were assumed to be linear elastic and isotropichowever thematerial of femur is very complex [19] Secondlythe analysis was limited to axial loading case and torsionalloading was not tested in this study the main muscle loadwas not included [20] Thirdly the screw-bone interface wasmodeled as a bond constraint although the constraint is agood approximation it cannot represent the real mechanicalenvironment of the fracture fixation [21] Therefore a futureinvestigation could entail experimental testing of the plate tosettle limitations

4 Conclusions

The present study presents an integrated computer-aidedapproach to conduct a parametric investigation of the designof patient-specific plates The study allows for improving thedesign efficiency of specific plates on the patientsrsquo femurparameters and the fracture information Furthermore thepresent approach will lead to exploration of plate modifica-tion and optimization The three-dimensional (3D) surfacemodel of a detailed femur and the corresponding fixation


plate were represented with high-level feature parametersand the shape of the specific plate was recursively modifiedbased on finite element analysis to obtain the optimal platefor a specific patient The proposed approach can be helpfulfor design users or surgeons to design and modify the platerapidly and efficiently to match specific fractured femurbones

Competing Interests

The authors declare that there are no competing interestsregarding the publication of this paper

Authorsrsquo Contributions

Xiaozhong Chen and Kunjin He made equal contribution tothe paper

Acknowledgments

This work was supported by Natural Science Foundation ofChina (Grant no 61472118) Science andTechnology Programof Jiangsu Province of China (Grant no BE2014048) NaturalScience Foundation of Jiangsu Province of China (Grant noBK20141158) High University Science Research Project ofJiangsu Province (Grant no 16KJB520047) Foundation ofChangzhou Vocational Institute of Engineering (Grant noKJ15303) and Qing Lan Project

References

[1] M Ehlinger G Ducrot P Adam and F Bonnomet ldquoDistalfemur fractures Surgical techniques and a review of the liter-aturerdquo Orthopaedics and Traumatology Surgery and Researchvol 99 no 3 pp 353ndash360 2013

[2] S Mardian K-D Schaser G N Duda and M HeylandldquoWorking length of locking plates determines interfragmentarymovement in distal femur fractures under physiological load-ingrdquo Clinical Biomechanics vol 30 no 4 pp 391ndash396 2015

[3] B B Batista R Salim C A J Paccola and M Kfuri JuniorldquoInternal fixators a safe option for managing distal femurfracturesrdquoActaOrtopedica Brasileira vol 22 no 3 pp 159ndash1622014

[4] C E Henderson T Lujan M Bottlang D C Fitzpatrick S MMadey and J L Marsh ldquoStabilization of distal femur fractureswith intramedullary nails and locking plates differences incallus formationrdquoThe Iowa Orthopaedic Journal vol 30 pp 61ndash68 2010

[5] D L Rothberg andM A Lee ldquoInternal fixation of osteoporoticfracturesrdquo Current Osteoporosis Reports vol 13 no 1 pp 16ndash212015

[6] E J Strauss R Schwarzkopf F Kummer and K A Egol ldquoThecurrent status of locked plating the good the bad and the uglyrdquoJournal of Orthopaedic Trauma vol 22 no 7 pp 479ndash486 2008

[7] M Cronskar L-E Rannar and M Backstrom ldquoImplemen-tation of digital design and solid free-form fabrication forcustomization of implants in trauma orthopaedicsrdquo Journal ofMedical amp Biological Engineering vol 32 no 2 pp 91ndash96 2012

[8] Y Okazaki ldquoDevelopment trends of custom-made orthopedicimplantsrdquo Journal of Artificial Organs vol 15 no 1 pp 20ndash252012

[9] L-T Ren Y-P Zhang Z-J Guo X-K Bu and S-Z LinldquoComputer-aided personalized anatomic plate of the distalfemurrdquo Journal of Clinical Rehabilitative Tissue EngineeringResearch vol 15 no 13 pp 2309ndash2312 2011

[10] X Shen J Zhang and P Du ldquoPersonalized design for dissectionsteel plate based on CT picture and reverse engineeringrdquoMachinery Design amp Manufacutre no 7 pp 161ndash162 2011

[11] J C Arnone S A El-Gizawy and B D Crist ldquoAn integratedcomputer-aided engineering approach for parametric investi-gation of locked plating systems designrdquo Journal of MedicalDevices vol 7 no 2 pp 411ndash417 2010

[12] X Chen K He Z Chen and L Wang ldquoA parametric approachto construct femurmodels and their fixation platesrdquo Biotechnol-ogy amp Biotechnological Equipment vol 30 no 3 pp 529ndash5372016

[13] X Chen K He Z Chen and W Xiang ldquoQuick constructionof femoral model using surface feature parameterizationrdquoMCBMolecular and Cellular Biomechanics vol 12 no 2 pp 123ndash1462015

[14] P J Nyirenda andW F Bronsvoort ldquoNumeric and curve param-eters for freeform surface feature modelsrdquo Computer-AidedDesign vol 40 no 8 pp 839ndash851 2008

[15] H E Cline W E Lorensen S Ludke C R Crawford and B CTeeter ldquoTwo algorithms for the three-dimensional reconstruc-tion of tomogramsrdquoMedical Physics vol 15 no 3 pp 320ndash3271988

[16] E ReinaromoMGiraldezsanchez and JMoramacıas ldquoBiome-chanical design of Less Invasive Stabilization System femoralplates computational evaluation of the fracture environmentrdquoProceedings of the Institution of Mechanical Engineers Part HJournal of Engineering in Medicine vol 228 no 10 pp 1043ndash1052 2014

[17] J Arnone A comprehensive simulation-based methodology forthe design and optimization of orthopaedic internal fixationimplants [PhD thesis] University of Missouri-ColumbiaColumbia Mo USA 2011

[18] M Nassiri B MacDonald and J M OrsquoByrne ldquoComputationalmodelling of long bone fractures fixed with locking platesmdashhow can the risk of implant failure be reducedrdquo Journal ofOrthopaedics vol 10 no 1 pp 29ndash37 2013

[19] F Taddei SMartelli andB Reggiani ldquoFinite-elementmodelingof bones from CT data sensitivity to geometry and materialuncertaintiesrdquo IEEE Transactions on Biomedical Engineeringvol 53 no 11 pp 2194ndash2200 2006

[20] U Schmidt R Penzkofer S Bachmaier and P Augat ldquoImplantmaterial and design alter construct stiffness in distal femurlocking plate fixation a pilot studyrdquo Clinical Orthopaedics andRelated Research vol 471 no 9 pp 2808ndash2814 2013

[21] A R MacLeod P Pankaj and A H R W Simpson ldquoDoesscrewndashbone interface modelling matter in finite element analy-sesrdquo Journal of Biomechanics vol 45 no 9 pp 1712ndash1716 2012

Submit your manuscripts athttpswwwhindawicom

Stem CellsInternational

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014


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EndocrinologyInternational Journal of



Disease Markers


BioMed Research International

OncologyJournal of



Oxidative Medicine and Cellular Longevity


PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

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Gastroenterology Research and Practice


Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom


models accurately and conveniently is very significant and itis a challenge to the development of a specific patient plate

Previously the authors proposed a parametric methodto construct a surface model of a patientrsquos femur based onsurface feature parameterization [12] It was found that thesurface model could be accurately constructed and modifiedaccording to the hierarchical feature parameters of a patientrsquosfemur [13] In this study a novel parametric method isproposed to develop a patient-specific plate based on thepatientrsquos information by using feature parameterization Theparametric models of femur plates can be quickly createdbased on parameter maps between the femur and the platemodified with a few semantic parameters and optimized byrecursively modifying plate shapes based on feature parame-ters To achieve this purpose three major requirements haveto be satisfied

(i) The plate should be designed according to the femuranatomy and fracture information (such as fracturetype and degree) of specific patients

(ii) The plate should be edited andmodified convenientlyby the physicians to match the morphology of aspecific patient bone

(iii) The creation and modification of the plate have tobe done within 24 hours after the injury to voidcomplications

Although there are lots of meaningful data in any frac-tured femur models these data are hard to measure and notdefined as parameters so that they are difficult to be used inthe representation and design of plates The research workreported in this paper is motivated by the above observationCombiningwith the thought of feature parameterization [14]themain contribution of this paper lies in the development ofa rapid method for the plate design from the fractured femurof a specific patient Our proposed method can support thedesign user to customize and optimize femur plates accordingto the information of specific patient

2 Materials and Methods

In this study an intact right femur of a young femalevolunteer without any disease or trauma was selected at ourresearch center

The complete framework for designing the custom platebased on the existing fractured femur of a specific patientis described in Figure 1 The major steps will be explainedfurther in the following parts of this section

21 Construction of the Fractured Bone Model To obtain 2Dscan images of the femur 64-slice CT (MSCT Aquilion 64Toshiba Zoetermeer Netherlands) was utilized After CTscanning of the selected femur by using the medical process-ing software MIMICS the intact 3D femur mesh model wascreated with four stages such as image preprocessing imagesegmentation surface extraction and mesh simplification[15]

A fracture gap was created 6 cm above the knee jointand the fractured segments were translated and rotated

3D fractured bone model

Specific patientrsquos CT

3D Construction

Yes

Reduced fractured model

Initial custom fracture plate

Custom fracture plate

Match

Model alignment

Constraint creation

Fractured bone of patient

CT scan

No

Figure 1 The flowchart of the design of a custom fracture plate

6 cm

Figure 2 The simulated 3D fractured femur mesh model with a33A1-C3 type fracture

to simulate a 33A1-C3 type fracture (AO-Classification) asshown in Figure 2

22 Reduction of Fractured Bone Segments In many femoralfractures the segments are usually comminuted and dis-located and the 3D fractured model cannot describe theaccurate morphologies of a normal femur Therefore the 3Dreconstruction of the intact femur representing the normalsurface shape of a specific patient especially of the fracturedsite is very useful for surgeons to select an optimal implantand treat the fracture

With the consideration of the significance of femur shapesin the plate design the authors focused on the surface modelof a intact femur and the surface model with the fractureevidences was constructed with the following step


Hr

(a) (b)

Fracture curves

(c)














Plate surface

(a)

Pw4

Pw3

Pw2

Pw1

Pl1

Pl2

Pl3

(b)

Pt1

Pt2

Pt3

Pt4

(c)


Model parameters

Contour parameters

Femur








30119875ℎ4 30




Parameters 1198751199081 1198751199082 1198751199083 1198751199084

Init 130 130 170 342Final 170 170 225 343





3 Discussions



Pt1

Pt2Pt3

Pt4 Pt5 Pt6

Pt7 Pt8Pt9

Pt10Pt11

Pt12

Pt13Pt14 Pt15

Pt16

Pt17

Pt18Pt19

MDC

MDF

P998400t1

P998400t2 P998400

t3

P998400t4

P998400t5

P998400t6

P998400t7

P998400t8

P998400t9

P998400t10

P998400t11 P998400

t12

P998400t13

P998400t14 P998400

t15

P998400t16

P998400t17 P998400

t18

P998400t19











(a)

(b)

(c)

Init plate

Final plate

Modified plate2mm

2mm

3mm

3mm 3mm

3mm3mm

3mm

4mm

4mm 4mm5mm



4 Conclusions




Competing Interests




Acknowledgments


References



























of






Disease Markers



OncologyJournal of





PPAR Research



Journal of

ObesityJournal of

















Hr

(a) (b)

Fracture curves

(c)














Plate surface

(a)

Pw4

Pw3

Pw2

Pw1

Pl1

Pl2

Pl3

(b)

Pt1

Pt2

Pt3

Pt4

(c)


Model parameters

Contour parameters

Femur








30119875ℎ4 30




Parameters 1198751199081 1198751199082 1198751199083 1198751199084

Init 130 130 170 342Final 170 170 225 343





3 Discussions



Pt1

Pt2Pt3

Pt4 Pt5 Pt6

Pt7 Pt8Pt9

Pt10Pt11

Pt12

Pt13Pt14 Pt15

Pt16

Pt17

Pt18Pt19

MDC

MDF

P998400t1

P998400t2 P998400

t3

P998400t4

P998400t5

P998400t6

P998400t7

P998400t8

P998400t9

P998400t10

P998400t11 P998400

t12

P998400t13

P998400t14 P998400

t15

P998400t16

P998400t17 P998400

t18

P998400t19











(a)

(b)

(c)

Init plate

Final plate

Modified plate2mm

2mm

3mm

3mm 3mm

3mm3mm

3mm

4mm

4mm 4mm5mm



4 Conclusions




Competing Interests




Acknowledgments


References



























of






Disease Markers



OncologyJournal of





PPAR Research



Journal of

ObesityJournal of

















Plate surface

(a)

Pw4

Pw3

Pw2

Pw1

Pl1

Pl2

Pl3

(b)

Pt1

Pt2

Pt3

Pt4

(c)


Model parameters

Contour parameters

Femur








30119875ℎ4 30




Parameters 1198751199081 1198751199082 1198751199083 1198751199084

Init 130 130 170 342Final 170 170 225 343





3 Discussions



Pt1

Pt2Pt3

Pt4 Pt5 Pt6

Pt7 Pt8Pt9

Pt10Pt11

Pt12

Pt13Pt14 Pt15

Pt16

Pt17

Pt18Pt19

MDC

MDF

P998400t1

P998400t2 P998400

t3

P998400t4

P998400t5

P998400t6

P998400t7

P998400t8

P998400t9

P998400t10

P998400t11 P998400

t12

P998400t13

P998400t14 P998400

t15

P998400t16

P998400t17 P998400

t18

P998400t19











(a)

(b)

(c)

Init plate

Final plate

Modified plate2mm

2mm

3mm

3mm 3mm

3mm3mm

3mm

4mm

4mm 4mm5mm



4 Conclusions




Competing Interests




Acknowledgments


References



























of






Disease Markers



OncologyJournal of





PPAR Research



Journal of

ObesityJournal of

















Pt1

Pt2Pt3

Pt4 Pt5 Pt6

Pt7 Pt8Pt9

Pt10Pt11

Pt12

Pt13Pt14 Pt15

Pt16

Pt17

Pt18Pt19

MDC

MDF

P998400t1

P998400t2 P998400

t3

P998400t4

P998400t5

P998400t6

P998400t7

P998400t8

P998400t9

P998400t10

P998400t11 P998400

t12

P998400t13

P998400t14 P998400

t15

P998400t16

P998400t17 P998400

t18

P998400t19











(a)

(b)

(c)

Init plate

Final plate

Modified plate2mm

2mm

3mm

3mm 3mm

3mm3mm

3mm

4mm

4mm 4mm5mm



4 Conclusions




Competing Interests




Acknowledgments


References



























of






Disease Markers



OncologyJournal of





PPAR Research



Journal of

ObesityJournal of



















(a)

(b)

(c)

Init plate

Final plate

Modified plate2mm

2mm

3mm

3mm 3mm

3mm3mm

3mm

4mm

4mm 4mm5mm



4 Conclusions




Competing Interests




Acknowledgments


References



























of






Disease Markers



OncologyJournal of





PPAR Research



Journal of

ObesityJournal of


















Competing Interests




Acknowledgments


References



























of






Disease Markers



OncologyJournal of





PPAR Research



Journal of

ObesityJournal of





















of






Disease Markers



OncologyJournal of





PPAR Research



Journal of

ObesityJournal of
















a novel computer-aided approach for parametric ...a fracture gap was created 6cm above the knee...

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