The biomechanical analysis of three-dimensional distal radius fracture model with different fixed splints

Abstract

BACKGROUND:

The distal radius fracture is one of the common clinical fractures. At present, there are no reports regarding application of the finite element method in studying the mechanism of Colles fracture and the biomechanical behavior when using splint fixation.

OBJECTIVE:

To explore the mechanism of Colles fracture and the biomechanical behavior when using different fixed splints.

METHODS:

Based on the CT scanning images of forearm for a young female volunteer, by using model construction technology combined with RPOE and ANSYS software, a 3-D distal radius fracture forearm finite element model with a real shape and bioactive materials is built. The material tests are performed to obtain the mechanical properties of the paper-based splint, the willow splint and the anatomical splint. The numerical results are compared with the experimental results to verify the correctness of the presented model. Based on the verified model, the stress distribution of different tissues are analyzed. Finally, the clinical tests are performed to observe and verify that the anatomical splint is the best fit for human body.

RESULTS:

Using the three kinds of splints, the transferred bone stress focus on the distal radius and ulna, which is helpful to maintain the stability of fracture. Also the stress is accumulated in the distal radius which may be attributed to flexion position. Such stress distribution may be helpful to maintain the ulnar declination. By comparing the simulation results with the experimental observations, the anatomical splint has the best fitting to the limb, which can effectively avoid the local compression.

CONCLUSION:

The anatomical splint is the most effective for fixing and curing the fracture. The presented model can provide theoretical basis and technical guide for further investigating mechanism of distal radius fracture and clinical application of anatomical splint.

Keywords

Distal radius fracture anatomical splint willow splint paper-based splint experiment finite element model stress analysis clinical tests

1. Introduction

Fracture is caused by different reasons which can be classified into internal causes and external causes. The internal reasons are reflected in the material properties and structures of the bone. And the external reasons are the magnitude and direction of the external force that imposed on the bone. The distal radius fractures are common injuries for the human motion system [1, 2, 3], which have always been attached great importance to in the clinical practice for high incidence.

Compared with other fractures of human body, the distal radius fractures occur more easily with more complex motions. The anatomical function, biomechanical behaviors and the motion mechanism are all still poorly understood. Existing etiology and pathology investigations on this fracture are still difficult to explain the fracture mechanism [4, 5, 6], which hinders the further improvement of clinical efficacy. Therefore, in recent years, many researchers performed extensive biomechanical experimental study on distal radius fractures [7, 8, 9, 10, 11]. They conducted mechanical tests on specimen and analyzed based on the collecting data. However, due to the restriction of objective conditions, the physiological conditions are hard to be truly reflected in the experiment. In addition, many experiments were performed in vitro condition [12, 13, 14, 15, 16], which were quite different from the real case in vivo condition. Furthermore, the cadaver specimen are unavailable or hard to obtain. Thus, how to select the research methods to replace the traditional experimental ways is the urgent need to solve the problem of biomechanical experimental research.

In recent years, advanced computational biomechanics analysis techniques have been gradually integrated into the clinical and basic research of medicine. In the orthopedics field, the application of finite element method is the most widely adopted [17, 18, 19, 20]. Compared with traditional biomechanical experiments, the finite element method has a lot of advantages with low cost, short-time computation, high-precision simulation and repeatability. In addition, the simulation method can complement the working conditions (or physiological conditions) that cannot be investigated through experimental methods [21, 22]. The application of the finite element analysis method in the field of bone biomechanics is mainly reflected in the following three aspects: 1. The analysis of skeletal system; 2. The analysis and design of orthopedic devices; 3. The analysis of growth, remodeling and degeneration of tissue. At present, there are no reports regarding application of the finite element method in studying the mechanism of distal radius fracture and the biomechanical behavior when using splint fixation.

Distal radius fracture is one of the common clinical fractures [23, 24, 25]. Its incidence accounts for about 17% of emergency fractures, and most of which is Colles fracture [26]. For simple, stable external and partial intra-articular fractures, the fixation splint is usually used after manipulative reduction for obtaining a satisfactory effect [27]. In this paper, in order to evaluate the therapeutic effect and safety of three different splints, based on the CT scanning images of forearm for a young female volunteer, by using model construction technology combined with RPOE and ANSYS software, a three-dimensional Colles fracture forearm finite element model with a real shape and bioactive materials is established. By performing simulation calculation, the stress distribution of different soft tissues and structures of forearm when subjected to bandage force with three different fixation splints are analyzed. Meanwhile, the fixation effects of three splints are compared. This paper provides a theoretical basis for the promotion and improvement of anatomical splint. In addition, the presented numerical model provides theoretical basis and technical guidance for further study on the biomechanical mechanism of distal radius fractures and the clinical application of anatomic splint.

2. Material

All the bone tissues and soft tissues are isotropic homogeneous elastic material. Based on published experimental data [28, 29, 30], the elastic modulus of compact bone is 13.3 GPa and the Poisson ratio is 0.3. The elastic modulus of cancellous bone is 0.69 GPa and the Poisson ratio is 0.3. The elastic modulus of soft tissues is 0.15 MPa and the Poisson ration if 0.49. The elastic modulus of cartilage is 10 MPa and the Poisson ratio is 0.45. The elastic modulus of ligament is 0.3 GPa and the Poisson ratio is 0.4. The elastic modulus of interosseous membrane is 0.95 GPa and the Poisson ratio is 0.45. In order to determine the mechanical properties of three fixation splints, the material mechanical tests were performed.

Table 1
Material properties of four willow splints

Group number	No. 1	No. 2	No. 3	No. 4
Elastic modulus (GPa)	13.6	14.7	13.9	14.2
Poisson ratio	0.27	0.31	0.33	0.28
Bending strength (GPa)	10.9	8.69	10.83	9.88
The averaged elastic modulus (GPa)	14.1
The averaged Poisson ratio	0.30
The averaged bending strength (GPa)	10.08

Table 2

Material properties of four paper-based splints

Group number	No. 1	No. 2	No. 3	No. 4
Elastic modulus (GPa)	11.8	12.6	11.9	12.1
Poisson ratio	0.20	0.18	0.23	0.20
Bending strength (GPa)	8.43	7.55	6.89	7.04
The averaged elastic modulus (GPa)	12.1
The averaged Poisson ratio	0.20
The averaged bending strength (GPa)	7.48

Table 3

Material properties of four anatomical splints

Group number	No. 1	No. 2	No. 3	No. 4
Elastic modulus (GPa)	13.8	13.6	13.9	13.1
Poisson ratio	0.23	0.28	0.26	0.25
Bending strength (GPa)	9.69	9.32	9.44	9.88
The averaged elastic modulus (GPa)	13.6
The averaged Poisson ratio	0.26
The averaged bending strength (GPa)	9.58

2.1 Material properties test of willow splint

In the test, four willow splints with the same size were selected. The length of the splint was 153 mm, the width 61 mm and the thickness 3 mm. Based on the theoretical model of cantilever beam in material mechanics theory, one end of the splint was fixed in three points by high-quality compression steel for ensuring the stability. The other end was loaded via a cast iron sheet with good bending rigidity for ensuring the force uniform on the splint. Domestic WCD-50 displacement sensor was used to measure the displacement. Based on the cantilever beam model in material mechanics theory, the elastic modulus and Poisson ratio can be obtained, as shown in Table 1. The elastic modulus, Poisson ratio and bending strength were measured and calculated to be 14.1 GPa, 0.3, and 10.08 GPa respectively.

2.2 Material properties test of paper-based splint

In the test, four willow splints with the same size were selected. The length of the splint was 165 mm, the width 66 mm and the thickness 3 mm. Based on the cantilever beam model in material mechanics theory, the elastic modulus and Poisson ratio can be obtained, as shown in Table 2. The elastic modulus, Poisson ratio and bending strength were measured and calculated to be 12.1 GPa, 0.2, and 7.48 GPa respectively.

Figure 1.

Preliminary 3D geometrical model of radius, ulna and wrist.

2.3 Material properties test of anatomical splint

In the test, four willow splints with the same size were selected. The length of the splint was 162 mm, the width 65 mm and the thickness 3 mm. Based on the cantilever beam model in material mechanics theory, the elastic modulus and Poisson ratio can be obtained, as shown in Table 3. The elastic modulus, Poisson ratio and bending strength were measured and calculated to be 13.6 GPa, 0.26, and 9.58 GPa respectively.

By comparing above three kinds of splints, the elastic modulus and bending strength of willow was found to be larger than the others. The following one is the anatomical splint and the paper-based splint is the least.

3. Methods

3.1 The geometrical model

A young female volunteer at age 27 with 165 cm height and 55 kg weight. There is a fracture in her distal radius which produces 30 degrees angle between the palm plane and forearm plane, and 15 degrees angle between the palm axis and the longitudinal axis of forearm.

Resorting to the CT scanning equipment, the human forearm data were collected. Using the gray segmentation technique, the hard and soft issues of the forearm which include the bones and muscles were extracted. In the following part, we focus on elaborating the data processing and model reconstruction of the main parts that include ulna, radius, metacarpal bone and muscle.

Figure 2.

The 3-D integrated geometrical model of forearm including radius, ulna, wrist and skin fusion.

Figure 3.

The finalized three-dimensional geometrical model of forearm including the hard and soft tissues.

In order to establish the three-dimensional solid model based on the 2D CT data, the Dicom data were need to be conversed and processed. Because the reconstruction method based on the CT or MRI imaging are all volumetric 3D reconstruction, and thus, the reconstruction model cannot be directly applied for further engineering treatment. Thus, the Dicom data were all imported into Mimics software and then the gray images of bone tissues and muscle were obtained. Firstly, all the imported images were preprocessed for improving resolution and smoothness. Secondly, using the selection tool of Mimics, the marrow cavity was regularized by removing the its internal discontinue regions. Thirdly, according to the gray value of different density of the tissues, the image data of muscle tissue other than bone were extracted. Then, the image data of ulna, radius and metacarpal were separated. Fourthly, due to the existing artifacts, holes and noise of the extracted model, by using the self-extraction function and erase filling function of this software, the image quality was improved by layer and layer and finally the rough model of bone tissues was obtained, as shown in Fig. 1.

The preliminary 3D geometrical model was triangular patch model which is coarse, distort and malformed. By importing the rough model into Geomagics software, the surface of the model was processed to become smooth and well fitted. In addition, the triangular patch model was then segmented, denoised and smoothing processed. Finally, the geometrical model including the soft tissues were obtained, as shown in Fig. 2.

The ligament, cartilage and cartilage disc were then constructed based on the CT data and anatomy knowledge. The complete 3-D geometrical forearm model contains the interosseous membrane of forearm tendon, ligament, radial scaphoid radioscaphoid ligament, radial head ligament, radioscapholunate ligament, ulnolunate ligament, ulnotriquetral ligament, ulnar capsule structure, palmar radioulnar ligament, dorsal radioulnar ligament, radial triangular ligament, radioulnar ligament and triangle triangular fibrocartilage disc, shown in Fig. 3.

The finalized geometrical model was exported from Geomagics and then was imported into PRO/E for further assembling with three kinds of splints respectively. It should be noted that the splints were designed according to the actual angle and shape of distal fracture. The finalized forearm geometrical models including the fixation splints were shown in Fig. 4.

Figure 4.

The finalized geometrical forearm model including three fixation splints.

Figure 5.

The mesh of three models.

3.2 Mesh of model

The ANSYS software was used to mesh the geometrical model. Adaptive sufficient mesh was used to ensure the accuracy of calculation. For this model, high-order tetrahedral elements were used to mesh the forearm. The ligaments were meshed with shell elements. The skin was meshed with Solid 185 elements. The total number of anatomical splint is 125932, the paper-based is 115493, and the willow splint is 135081. The meshes are shown in Fig. 5. In the software, the CONTACT element was used to define the contact pairs between splint and bone. Because the surface of the splint was the loading surface, the splint part was defined as target surface and the bone part was defined as contact surface. The target surface and contact surface elements were both tracking the motion of the deformation elements, thus called contact pairs.

3.3 Boundary conditions

The boundary conditions and two different load cases were defined as follows:

(1) (1)
The radius and ulna proximal were fully constrained in three different coordinate directions. The contact pairs were set in the interface among bone, soft tissues and joint surface. The friction coefficient is assumed to be 0.002. A total of 100 N pressure load was applied in the second metacarpal bones and the third metacarpal bones along the hand and forearm.
(2)
The radius and ulna proximal were fully fixed. The contact pairs were set in the interface among bone, soft tissues and joint surface. The friction coefficient is assumed to be 0.002. Applying 10 N concentration load at the center of each splint.

Figure 6.
Comparison of the simulation stress results of the wrist joint surface and the experimental results.

Figure 7.
The stress distribution of the soft tissues fixed by the willow splint.

4. Results

4.1 Model verification

Based on the presented finite element model, the stress distribution of the articular surface of the wrist joint were obtained, as shown in Fig. 6a. The stress distribution is uneven, and the maximum stress is located in the ulnar and ulnar bones of lunate bone. The maximum value approximates 9.45 MPa. In the previous literature [28], the maximum contact stress of the joint surface of the wrist joint was shown to be about 10 MPa and the stress was mainly concentrated on the ulnar and ulnar bones. By comparing the presented numerical results with those in the experiment [29], the difference of the maximum stress approximates only 5.5%. And the stress distribution are also in similarity. And the similar simulation results can also be found in other literature [19, 30]. Thus, the presented model is verified to be accurate and can be used to predict other results that the previous measurements cannot predict.

Figure 8.

The stress distribution of the soft tissues fixed by the paper-based splint.

Figure 9.

The stress distribution of the soft tissues fixed by the anatomical splint.

Figure 10.

The stress distribution of the bones fixed by the willow splint.

Figure 11.

The stress distribution of the bones fixed by the paper-based splint.

Figure 12.

The stress distribution of the bones fixed by the anatomical splint.

Figure 13.

The observation of the limb fitting effect of the distal radius anatomical splint (A. The observed splint fitting of one case; B. Elbow joint activity after fixation; C. Metacarpophalangeal joint activity after fixation; D. Suspension fixation.).

4.2 Biomechanical behaviors of the soft tissue

Based on the verified finite element model, by subjecting 10 N concentrated bandage load that perpendicular to the splint surface in the center of the splint, the stress distribution of the soft tissues were obtained, as shown in Figs 7–9. The unit of the value in the figures is MPa.

4.3 Biomechanical behaviors of the bones

Based on the verified finite element model, by subjecting 10 N concentrated bandage load that perpendicular to the splint surface in the center of the splint, the stress distribution of the bones were obtained, as shown in Figs 10–12. The unit of the value in the figures is Pa.

4.4 Experiment of fitting effect of the anatomical splint using in human forearm

Based on the above simulation results, the anatomical splint has the best fixation effect. In order to verify the results, clinical experiments on the body-fitting effect of the anatomical splint have been performed. The fitting effects of the splint that used in the distal radius fracture are observed, as shown in Fig. 15. In the experiment, ten adult volunteers from the physical examination center of Wuxi Affiliated Hospital of Nanjing University of Chinese Medicine from May to July in 2015 were selected to be observed. The medium size of the anatomical splints were fixed for one week. The dynamic fitting effects of the splint with the bone protrusion, thenar and limb were observed. It is found that there exists a gap in only one case. After adjusting the splint by less than 5 degrees, a satisfying fitting effect was obtained. In all cases, elbow flexion and extension of the metacarpophalangeal joint were not affected. In addition, there were no oppressive feeling of apophysis and thenar, and there were no local skin pressure mark in the splint after 1 week. Thus it can be seen that the distal radial anatomic splint has the characteristics of local anatomy, no need of excessive plasticity and convenient clinical application.

Figure 14.

The maximum stress of the soft tissues fixed by three kinds of splints.

Figure 15.

The maximum stress of the bones fixed by three kinds of splints.

5. Discussion

For the three splints, the limb soft tissue with willow splint is subjected to the maximum stress which focuses on the wrist joint, thenar, hypothenar and proximal forearm. The stress of limb soft tissue with paper-based splint is still nonuniform and with the stress concentration on the same places. For the anatomical fixation splint, the stress distribution is regular with no stress concentration on the bone protrusion and thenar parts.

As shown in Fig. 15, when the willow splint is used, the maximum stress approximates 0.69 MPa. When the paper-based splint is adopted, the maximum stress is about 0.61 MPa. Compared with the above two splints, when using the anatomical splint, the maximum stress is about 0.56 MPa, which is smaller than the other cases. By comparing three kinds of splints, the stress of soft tissues when using anatomical splint is the minimum and the most evenly distributed. The stress is the largest when using willow splint with large stress accumulation on the bony prominence and hypothenar of multiple proximal forearm. The paper-based splint is in between. The anatomical splint is found to be more fit with limb than the other two splints because it can avoid excessive compression of the easily compressed part which is in line with our design intention. Meanwhile, the high stress concentration regions of the willow splint and paper-based splint are consistent with the positions of blisters and pressure ulcer in the clinical work, which verifies the accurate and reliability of the presented finite element model.

As shown in Fig. 15, when the willow splint is fixed on the forearm, the maximum stress of the carpal bones reaches 0.42 MPa. When the paper-based splint is used, the maximum stress of the carpal bones reaches 0.39 MPa. When the anatomical splint is adopted, the maximum stress of metacarpus is about 0.27 MPa. When the willow fixation splint is used, the carpal bones near the articular surface is under stress concentration. In addition, the junction of the styloid process of the radius and ulnar bones of the wrist and larger are also with large stress, whereas the stress of the metacarpal part is small and evenly distributed. It is because the fixed length of the willow splint is not within the region of the finger joints. When the paper-based splint is used, the stress still concentrates on the junction of carpal joint, styloid process of radius and ulnar bones and wrist. In this case, the stress on metacarpal is larger than that of willow splint. The first and the fifth metacarpal are subjected to large stress, which may be attributed to compression of the ulnar and radial sides of the splint. When using the anatomical splint, there is a uniform stress on the wrist bone as well as other parts except the in the articular surface of the distal radius and ulna. Moreover, the first and the fifth metacarpal bone show no obvious stress concentration, which does not affect the metacarpophalangeal joint activities.

6. Conclusion

In this paper, based on the CT scanning images of forearm for a young female volunteer, by using model construction technology combined with RPOE and ANSYS software, a three-dimensional distal radius fracture forearm finite element model with a real shape and bioactive materials is built. The material tests are performed to obtain the mechanical properties of the paper-based splint, the willow splint and the anatomical splint. The forearm is subjected to a 100 N pressure along the forearm axis and then the distribution of contact stress on the joint surface of wrist joint is obtained. The numerical results are compared with the experimental results to verify the correctness of the presented model. Based on the verified model, the stress distribution of different tissues are analyzed and we find that the anatomical splint is the most effective for fixing and curing the fracture. Using this splint, the stress distribution of the limb is even and concentrated in the wrist, peripheral radial thenar and proximal forearm. Finally, the clinical tests are performed to observe and verify that the anatomical splint is the best fit for human body. Some conclusion are drawn as follows:

(1) (1)

The limb soft tissue when using willow splint is subjected to the maximum stress which focuses on the wrist joint, thenar, hypothenar and proximal forearm. The carpal bones near the articular surface is also under stress concentration. In addition, the junction of the styloid process of the radius and ulnar bones of the wrist and larger are also with large stress, whereas the stress of the metacarpal part is small and evenly distributed. It is because the fixed length of the willow splint is not within the region of the finger joints.

(2)

The stress of limb soft tissue with paper-based splint is still nonuniform and with the stress concentration on the wrist joint, thenar, hypothenar and proximal forearm. Moreover, for the stress on bone, the stress concentrates on the junction of carpal joint, styloid process of radius and ulnar bones and wrist. In this case, the stress on metacarpal is larger than that of willow splint. The first and the fifth metacarpal are subjected to large stress, which may be attributed to compression of the ulnar and radial sides of the splint.

(3)

By adopting the three kinds of splints, the transferred bone stress focus on the distal radius and ulna, which is helpful to maintain the stability of fracture. Moreover, the stress of the radial joint surface of the radius is inclined to the ulnar and ulnar bones of the lunate bone. Also the stress is accumulated in the distal radius which may be attributed to flexion position. Such stress distribution may be helpful to maintain the ulnar declination.

(4)

By comparing the simulation results with the experimental observations, the anatomical splint has the best fitting to the limb, which can effectively avoid the local compression.

The presented model can provide theoretical basis and technical guide for further investigating mechanism of distal radius fracture and clinical application of anatomical splint. However, in this model, the materials of all the structures were assumed to be isotropic and with linear elastic properties. Actually, the soft tissue are anisotropic and viscoelastic. Thus, this can be improved in our future study.

Footnotes

Acknowledgments

The authors thank Tao Hua from Tongji University for his great help in finite element analysis. This paper is supported by Science and Technology Project of Wuxi (CSE31N1514), Health and Family Planning Commission Project of Wuxi (Q201504).

Conflict of interest

None to report.

References

Chung

Shauver

Birkmeyer

. Trends in the United States in the treatment of distal radial fractures in the elderly. J Bone Joint Surg Am 2009; 91(8): 1868-1873.

Song

. Comparison of conservative and operative treatment for distal radius fracture: A meta-analysis of randomized controlled trials. Int J Clin Exp Med 2015; 8(10): 17023-17035.

Henn

Wolfe

. Distal radius fractures in athletes: Approaches and treatment considerations. Sports Med Arthrosc 2014; 22(1): 29-38.

White

Rollick

. Injuries of the Scapholunate Interosseous Ligament: An Update. J Am Acad Orthop Surg 2015; 23(11): 691-703.

Gunther

Lynch

. Rigid internal fixation of displaced distal radius fractures. Orthopedics 2014; 37(1): e34-38.

Harreld

. Iconography: Intramedullary fixation of distal radius fractures. J Am Chem Soc 2004; 126(9): 2696-2703.

Çelik

Kovacı

Saka

Kaymaz

. Numerical investigation of mechanical effects caused by various fixation positions on a new radius intramedullary nail. Comput Methods Biomech Biomed Engin 2015; 18(3): 316-324.

Baumbach

Dall’Ara

Weninger

Antoni

Traxler

Dörr

Zysset

. Assessment of a novel biomechanical fracture model for distal radius fractures. BMC Musculoskelet Disord 2012; 13: 252.

Burkhart

Andrews

Dunning

. Multivariate injury risk criteria and injury probability scores for fractures to the distal radius. J Biomech 2013; 46(5): 973-978.

10.

Matsuura

Kuniyoshi

Suzuki

Ogawa

Sukegawa

Rokkaku

Takahashi

. Accuracy of specimen-specific nonlinear finite element analysis for evaluation of distal radius strength in cadaver material. J Orthop Sci 2014; 19(6): 1012-1018.

11.

Bhatia

Edwards

Troy

. Predicting surface strains at the human distal radius during an in vivo loading task – finite element model validation and application. J Biomech 2014; 47(11): 2759-2765.

12.

Synek

Chevalier

Schröder

Pahr

Baumbach

. Biomechanical testing of distal radius fracture treatments: Boundary conditions significantly affect the outcome of in vitro experiments. J Appl Biomech 2016; 32(2): 210-214.

13.

Khader

Towler

. Common treatments and procedures used for fractures of the distal radius and scaphoid: A review. Mater Sci Eng C Mater Biol Appl 2017; 74: 422-433.

14.

Dolce

Goodwin

Ludwig

Edwards

. Intraoperative evaluation of dorsal screw prominence after polyaxial volar plate fixation of distal radius fractures utilizing the Hoya view: A cadaveric study. Hand (NY) 2014; 9(4): 511-515.

15.

Nishiwaki

Welsh

Gammon

Ferreira

Johnson

King

. Volar subluxation of the ulnar head in dorsal translation deformities of distal radius fractures: An in vitro biomechanical study. J Orthop Trauma 2015; 29(6): 295-300.

16.

Reeves

Burkhart

Dunning

. The effect of static muscle forces on the fracture strength of the intact distal radius in vitro in response to simulated forward fall impacts. J Biomech 2014; 47(11): 2672-2678.

17.

Brekelmans

Poort

Slooff

. A new method to analyse the mechanical behaviour of skeletal parts. Acta Orthop Scand 1972; 43(5): 301-317.

18.

Rybicki

Simonen

Weis

. On the mathematical analysis of stress in the human femur. J Biomech 1972; 5(2): 203-215.

19.

Pfeiffer

. The use of finite element analysis to enhance research and clinical practice in orthopedics. J Knee Surg 2016; 29(2): 149-158.

20.

Hussain

Natarajan

Andersson

. Reduction in segmental flexibility because of disc degeneration is accompanied by higher changes in facet loads than changes in disc pressure: A poroelastic C5-C6 finite element investigation. Spine J 2010; 10(12): 1069-1077.

21.

Postigo

Schmidt

Rohlmann

Putzier

Simón

Duda

Checa

. Investigation of different cage designs and mechano-regulation algorithms in the lumbar interbody fusion process – a finite element analysis. J Biomech 2014; 47(6): 1514-1519.

22.

Chen

Lee

Lin

Tsai

Wei

. Biomechanical comparison of conventional and anatomical calcaneal plates for the treatment of intraarticular calcaneal fractures – a finite element study. Comput Methods Biomech Biomed Engin 2016; 19(13): 1363-1370.

23.

Jung

Hong

Jung

Kim

Park

Bae

Jeon

. Redisplacement of distal radius fracture after initial closed reduction: Analysis of prognostic factors. Clin Orthop Surg 2015; 7(3): 377-382.

24.

Brogan

Richard

Ruch

Kakar

. Management of severely comminuted distal radius fractures. J Hand Surg Am 2015; 40(9): 1905-1914.

25.

O’Connor

Mullett

Doyle

Mofidi

Kutty

O’Sullivan

. Minimally displaced Colles’ fractures: A prospective randomized trial of treatment with a wrist splint or a plaster cast. J Hand Surg Br 2003; 28(1): 50-53.

26.

Arnander

MWT

Newman

KJH

. Fractures of the distal radius. Surgery 2006; 24(12): 429-432.

27.

Jin

Hou

. Comparison of treatment outcomes between nonsurgical and surgical treatment of distal radius fracture in elderly: A systematic review and meta-analysis. Langenbecks Arch Surg 2015; 400(7): 767-779.

28.

Gislason

Stansfield

Nash

. Effects of partial wrist arthrodesis on loading at the radiocarpal joints. 17th Congress of the European Society of Biomechanics 2010; Edinburgh, UK.

29.

Bajuri

Kadir

Raman

Kamarul

. Mechanical and functional assessment of the wrist affected by rheumatoid arthritis: A finite element analysis. Med Eng Phys 2012; 34(9): 1294-1302.

30.

Mouzakis

Rachiotis

Zaoutsos

Eleftheriou

Malizos

. Finite element simulation of the mechanical impact of computer work on the carpal tunnel syndrome. J Biomech 2014; 47(12): 2989-2894.