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post-operative hallux valgus: A comparative study
Accepted Manuscript Biomechanical evaluation of the first ray in pre-/post-operative hallux valgus: A comparative study
Junchao Guo, Lizhen Wang, Rui Mao, Cheng Chang, Jianmin Wen, Yubo Fan PII: DOI: Reference:
S0268-0033(18)30225-0 doi:10.1016/j.clinbiomech.2018.06.002 JCLB 4545
To appear in:
Clinical Biomechanics
Received date: Accepted date:
26 March 2018 4 June 2018
Please cite this article as: Junchao Guo, Lizhen Wang, Rui Mao, Cheng Chang, Jianmin Wen, Yubo Fan , Biomechanical evaluation of the first ray in pre-/post-operative hallux valgus: A comparative study. Jclb (2017), doi:10.1016/j.clinbiomech.2018.06.002
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ACCEPTED MANUSCRIPT Title page Biomechanical
evaluation
of
the
first
ray
in pre-/post-operative
hallux
valgus:
A
comparative study
Authors List: ※
※
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Junchao Guoa , Lizhen Wangb , Rui Maob, Cheng Changc, Jianmin Wenc*, Yubo Fana,b*
a, Beijing Key Laboratory of Rehabilitation Technical Aids for Old-Age Disability, Key Laboratory of
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Human Motion Analysis and Rehabilitation Technology of the Ministry of Civil Affairs, National Research Center for Rehabilitation Technical Aids, 100176 Beijing, PR China
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b, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, 100191 Beijing, PR China
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c, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China
* Corresponding author. Yubo Fan, Ph.D, Professor
School of Biological Science and Medical Engineering, Beihang University, Beijing, China *Co-corresponding author:
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Jianmin Wen, Ph.D, Professor
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E-mail: [email protected], Tel.: +86 10 8233 9428.
Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China E-mail: [email protected], Tel: +86-10-84739008
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※ Two authors contribute to the work
Word count: Main Text: 3125 Abstract: 240 Number of Figures:8
ACCEPTED MANUSCRIPT Abstract Background: Deformity of the first ray in hallux valgus patient has been deemed to mainly contribute to instability of the metatarsophalangeal joint. However, it is not clear whether the fixation of the distal osteotomy fragment and transposition of the sesamoid represent the best method for hallux valgus treatment. The aim of this study was to examine how postoperative hallux valgus osteotomy affects the
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stability of the first ray. Methods: To accurately investigate the biomechanical behavior of the first ray in pre-/postoperative
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hallux valgus patients, we described the relative displacement and stress distribution of the first
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metatarsal bone and sesamoid by imageology, test measurement and foot finite element model. Findings: Compared with the preoperative hallux valgus, the plantar pressure decreased by 47.8% and
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was redistributed on second metatarsal region. The peak stress and relative displacement of the distal osteotomy fragment increased by +55.7% and -59.9%, respectively. The movement of this component
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shifted toward the positive sagittal axis direction. In addition, the relative displacement of sesamoid decreased by 87.4% (0.18mm) in vertical axis direction and the stress was also redistributed on medial
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and lateral region. Moreover, the strain of the medial main ligament was more favorable to reconstruct
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function of the first ray.
Interpretation: The findings showed that the osteotomy method was helpful for stability of the first ray.
rehabilitation.
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This would provide the stability suggestions for postoperative hallux valgus fixation and guide further
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Keywords: Hallux valgus; Pre-/postoperative hallux valgus; The first ray; Distal osteotomy fragment
ACCEPTED MANUSCRIPT 1. Introduction Hallux valgus (HV) with an incidence rate of 2-4% of the population is a complex malposition of the first ray in foot deformities (Heizmann et al., 2012). The prevalence is up to 33% in adult (Matzaroglou et al., 2010). It is particular common for female to occur during the wearing constrictive or high heel shoes (Robinson et al., 2005). The evident deformity of the medial protrusion seriously affects the mechanotrans-duction in first metatarsophalangeal joint (Easley et al., 2007). Instability and
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pain of joint would also induce defected functionality of the first ray (Daniel et al., 2008). The complications with the callus, bunion, pain and deformity seriously affect the gait and forefoot health
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(Easley et al., 2007).
The current treatments for HV deformity mainly include the conservative management and the
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surgical intervention. The conservative managements are suitable for early HV complication such as bunions, callus (Tang et al., 2002). Nevertheless, the surgical intervention is used to the moderate or
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severe HV deformity (Wu et al., 2014).
The conservative management in early treatment is a choice for the HV correction. Especially for
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the early protrusion bunion, the orthotic devices of foot and toe spacer pads (Tang et al., 2002), the fixation taping (Jeon et al., 2004), exercise of the rehabilitation training (Bek et al., 2002) and the correction of orthotic footwear (Brantingham et al., 2005) will well correct deformities of the first ray
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and prevent the further complication of HV. The treatment methods take less cost and longer time (Gul
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et al., 2015). Unfortunately, the conservative treatment has shown the insufficient pain relief and difficult early discovery (Brantingham et al., 2012). With the more obvious of HV symptoms, the different surgical interventions are used and
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assessed by the study, such as the proximal metatarsal osteotomy, "V" type osteotomy (Matzaroglou et al., 2010; Migues et al., 2007; Meir et al., 2002; Trnka et al., 2013). These treatments could cause the negative effect and the postoperative complication (Migues et al., 2007; Trnka et al.,
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2013). For example, hallux rigidus, rheumatoid arthritis, neuromuscular instability under the different fixation technologies conditions (Ella et al., 2016); The negative effect of the redistribution load on the underlying bones, tendons and neurovascular structures (Chen et al., 2014); Arthritis and instability of the distal metatarsal fragment by the Chevron osteotomy (Meir et al., 2002); Avascular necrosis of the first metatarsal head (Yasser et al., 2012). Those reports used the different osteotomy techniques to stabilize the joint and prevent unstable migration of the distal fragment (Meir et al., 2002). It was also shown that the surgical intervention could improve muscle function and the activity of the metatarsophalangeal joint (Matzaroglou et al., 2010). However, there is no consensus on the best operative method for HV (Chen et al., 2014; Yasser et al., 2012). In recent years, the minimally invasive techniques have been reported and accepted by HV
ACCEPTED MANUSCRIPT patients (Bek et al., 2002). The minimal incision osteotomy as a significant advantage has the feature of rapid healing, low risk of complication and minimal shortening of the first metatarsal ray (Yasser et al., 2012). Compared with the evidence of the previous surgical technique (Bek et al., 2002; Brantingham et al., 2005; Migues et al., 2007; Meir et al., 2002), the minimally invasive techniques of Giannini (Giannini et al., 2013), Bösch (Bösch et al., 1994) and Wen's (Sun et al., 2010) methods are widely used to correct deformity of the first ray. However, the accurate surgery of HV such as the effect of
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wedge angle on osteotomy fragments (Giannini et al., 2013) and the effect of fixation methods on first metatarsal head (Giannini et al., 2013; Bösch et al., 1994; Sun et al., 2010; Mao et al., 2017) are still no definite unity for severe HV treatment.
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Therefore, the aim of this study is to assess the effect of the distal osteotomy method on
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postoperative HV (Fig.1) (Sun et al., 2010; Wen et al., 2002), using the experimental measurement and foot finite element model to compare the biomechanical behavior of the first ray in pre-/postoperative
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hallux valgus. 2. Materials and Methods
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2.1. Experiment testing
A female of HV patient (without any foot lesion and pathology except for HV) participated in minimally invasive treatment of the distal osteotomy. X-ray images of preoperative HV showed the
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magnitude of the hallux valgus angle (HVA) (35.62°), the first and second intermetatarsal angle (IMA)
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(20.26°) compared to the HVA (14.2°) and IMA (8.2°) of postoperative condition (Fig.2). The HVA and IMA were measured by MIMICS10.01 software (Materialise, Belgium). Pre-/postoperative plantar pressures of the subject were measured by the RSscan system (RSscan,
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Belgium). The plantar foot in system was divided into ten regions (the first toe, the second to fifth toes, the first, second, third, fourth and fifth metatarsals, midfoot, the heel medial and lateral) (Guo et al., 2016). In addition, the Tactilus 4.0 system (50HZ of the sampling frequency) with 32 test channels was
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used to measure the five surface pressures of metatarsal region by bandage fixation of "8" type during foot balance standing (Fig.3). The average values of five regions were shown in Table.1. The values were applied to boundary conditions of the following foot finite element (FE) model (Mao et al., 2017). 2.2. Foot FE model The pre-/postoperative HV FE models were acquired from CT images of the above female (26 years old; 54kg weight) during the unloaded condition. The 224 images in MIMICS were segmented to obtain the contours of bones and skin tissue. Then these components were processed by the Geomagic 12.0 software (Geomagic 12.0, NC27709, US) to form solid models. The foot models included 28 bones, 2 sesamoids, cartilages, main ligaments, Achilles's tendon, plantar soft tissue and skin.
ACCEPTED MANUSCRIPT Ligaments based on the anatomical location between the bones were defined as the truss element in ABAQUS software (ABAQUS 6.13, Simulia Inc, US). The cartilages were formed based on joint contact surface. To effectively investigate the biomechanical behavior of HV model, the forefoot bones except for the first ray was fused together by the resembling cartilaginous structure (Mao et al., 2017; Guo et al., 2016; Cheung et al., 2004). The contact relationship between the bones was defined by the relatively accurate movement. Surface-to-surface contact was used in interaction option of ABAQUS.
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All the tissues were meshed with a total of 386868 (Fig.4a) and 330977 (Fig.4c) elements. All tissues except for the plantar soft tissue were defined as linearly elastic, homogeneous and isotropic material. The elastic modulus and poisson’s ratio of bones were assigned as 7300MPa and 0.3,
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respectively (Gefen et al., 2000). A coefficient of friction of 0.6 was used for contact surfaces between
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the foot and ground (Zhang et al., 1994). Articular cartilage surfaces were defined by frictionless (Cheung et al., 2004). Plantar fascia was defined with 350MPa and the cross-sectional area of
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290.7mm2 (Spyrou et al., 2012). The mechanical properties of cartilage (Athanasiou et al., 1998) and ligaments (Siegler et al., 1988) in Table 2 are cited from the literatures. The plantar soft tissue was simulated with the strain energy function (U) of a first-order Ogden form (Twizell et al., 1983) as:
1-3
2
1
2 3 3
are the deviatoric principal stretches.
(1)
(16.45KPa) and (6.82) (Twizell et al., 1983)
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where
2
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U
are the material properties representing the hyperelastic behavior of the plantar soft tissue (Petre et al.,
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2013).
In load setting of two foot FE models in ABAQUS software, a foot loaded about a half of subject weight (54kg). 270N force as external loading was applied to plantar foot against ground. The upward
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vertically force was about 135N to simulate the equivalent force vectors at Achilles tendon (Guo et al., 2016; Cheung et al., 2004) (Fig.4b and 4d). Except for the above setting condition, five surface
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pressures of the first ray (Table 1) were used in postoperative foot FE model (Fig.4d). We used the displacement of a reference point on calcaneus surface to test the convergence of two FE models due to similar consideration for the other bones. The contact force between the calcaneus and the ground was loaded with a uniformly distribution of 0.1MPa. Ten different element amounts were compared by the pre/postoperative models, including: 404218, 398470, 386868, 371805, and 366547 elements for the preoperative model; 369924, 354228, 330977, 315820 and 301548 elements for the postoperative model. The different element amounts were tested to compare the displacements of the reference point. 404218 and 369924 element amounts were compared with the displacement of the reference point in two FE models, respectively. The displacement errors with the total model were within 1.54%. The test results showed that the total of 386868 and 330977 elements
ACCEPTED MANUSCRIPT in two models were selected based on the smallest relative error of 0.27% and 0.31%. Therefore, the element amounts (386868 and 330977) were applied to all foot FE models. 3. Results The pre-/postoperative HV FE models were validated by the results of RSscan measurement (Fig.5). Peak pressure of 0.46MPa and 0.24MPa in two FE models concentrated on the third metatarsal
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and the second metatarsal regions, respectively. The results were consistent with the RSscan measurements of the pre-/postoperative plantar pressure. Whilst the measured values of 0.41MPa and 0.18MPa were slightly lower than the FE models prediction.
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The stress distribution (Fig.6a) and the relative displacement (Fig.6b) of the first metatarsal
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bone were shown in Fig.6. Peak stress of the first metatarsal bone were 3.352MPa and 2.847MPa, respectively. Compared with the peak stress (1.063MPa) of the distal osteotomy fragment in
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preoperative HV model, the value increased up to 1.655MPa in the postoperative model (Fig.6a). The relative displacement of the first metatarsal bone decreased by 59.9% compared to the preoperative result of 1.451mm. In contrast to the positive vertical axis direction of the preoperative first metatarsal
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bone, it shifted toward the positive sagittal axis direction in postoperative FE prediction (Fig.6b). The stress distribution (Fig.7a) and the relative displacement (Fig.7b) of the sesamoid were shown in Fig.7. Peak stress of 3.084MPa concentrated on the lateral sesamoid region in preoperative model.
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Although the peak stress of 6.29MPa was also the same location in postoperative HV, the stress region
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was redistributed into the medial sesamoid (Fig.7a). Compared with the relative displacement (1.56mm) of sesamoid, the value was decreased by 62.6% in postoperative HV (Fig.7b). The displacement decrement (87.4%) of sesamoid mainly changed in vertical axis direction (Table.3).
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The strain of the medial main ligaments in first ray was shown in Fig.8. In contrast to plantar fascia (PF), tibiocalcanean ligament (Tib-CalL), tibionavicular ligament (Tib-NavL), calcaneonavicular
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ligament (Cal-NavL), dorsal cuneonavicular ligaments (DCun-NavL), plantar cuneonavicular ligaments (PCun-NavL), dorsal tarsometatarsal ligaments (DTar-MetaL) displacement values of 1.75, 0.19, 0.21, 0.28, 0.32, 0.49 and 0.94mm in preoperative HV model, the displacement of the above ligaments increased by -49.7%, +21.0%, +99.3%, +66.1%, +34.9%, -10.9% and -46.2% in postoperative prediction, respectively (Fig.8). 4. Discussion In this study, two models were used to investigate the biomechanical behavior of the first ray. The computational models of pre-/postoperative HV were validated by the results of RSscan measurement. Plantar pressure regions of two models under full weight bearing conditions were similar to the result
ACCEPTED MANUSCRIPT of RSscan measurement. In contrast to peak pressure of the third metatarsal region (Fig.5), plantar pressure of the postoperative HV was shifted toward the second metatarsal. This result was consistent with the normal plantar pressure from the literatures (Guo et al., 2016; Cheung et al., 2004). The validated method of plantar pressure measurement was also used in many studies (Mao et al., 2017;
Guo et al., 2016; Cheung et al., 2004; Gefen et al., 2000). However, the peak pressure of FE prediction was slightly greater than the measurement value (Fig.5). Except for limitations of the material
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properties and the simplified FE model (Mao et al., 2017; Guo et al., 2016; Cheung et al., 2004; Gefen et al., 2000), this difference may result from the incomplete function of soft tissue in postoperative HV (Easley et al., 2007).
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In clinical investigation and practice, the deformity and pain of the first ray were the most
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common symptom in HV patients (Heizmann et al., 2012; Easley et al., 2007; Daniel et al., 2008). HVA and IMA in clinical study were usually used to evaluate the severity degree of HV deformity (Mattos et al., 2007). The two parameters in our test were 35.62° and 20.26°, respectively. The values were
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included in range of deformity degree (HVA≤40°and IMA≤20°) (Wu et al., 2014). Although the data was from a female measurement, the pathologic behavior of HV was unity and commonality (Bek et al.,
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2002; Brantingham et al., 2012; Migues et al., 2007; Meir et al., 2002; Yasser et al., 2012; Giannini et al., 2013; Sun et al., 2010; Mattos et al., 2007). The values were statistically significant from the study (Mattos et al., 2007). This female subject could also represent this kind of HV patients that the
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symptom was consistent with the literature reports (Mattos et al., 2007; Daniel et al., 2008; Kota et al.,
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2017). Also, it was particular common for female to have HV deformity (Robinson et al., 2005). Therefore, the foot FE models by the convergence test and validation (Fig.4) would be reliable to investigate the biomechanical behavior of the first ray.
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For minimally invasive treatment of HV, stability of the first ray was an important effect for the postoperative rehabilitation time (Meir et al., 2002; Trnka et al., 2013; Chen et al., 2014). In present
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study, the 25% translation of the distal fragment relative to the osteotomy surface was reasonable scope of 25～50% by the literatures (Pique-Vidal et al., 2006). The relative sagittal axis movement direction of the distal osteotomy fragment (Fig.6b) would increase contact of the fragment surface (Mao et al., 2017). This could accelerate the healing of bone injury or osteotomy surface (Guo et al., 2015). Furthermore, the relative displacement of the distal fragment reduced by 59.9% compared to the 1.45mm of preoperative HV (Fig.6b). It was indicated that the osteotomy method was advantageous to increase the stability of the cutting surface (Daniel et al., 2008). From the FE prediction, the peak stress (2.847MPa) of the postoperative first metatarsal bone concentrated on the osteotomy surface compared to the preoperative HV (Fig.6a). The loading case could well induce the osteocyte growth between the proximal and distal osteotomy fragment. It accelerated the coalescence of osteotomy surface (Chao et
ACCEPTED MANUSCRIPT al., 1982). This would shorten the healing time of the postoperative osteotomy fragment (Chao et al., 1982). Meanwhile, the bandage fixation could well stabilize the first ray (Jeon et al., 2004; Brantingham et al., 2012). Moreover, the peak stress (1.655MPa) of the postoperative distal fragment also increased by 55.7% contrast to 1.063MPa of the preoperative FE prediction (Fig.6a). The higher peak stress was more helpful to bone healing of the postoperative HV (Chao et al., 1982; Kai et al., 2005). It was consistent with results that the stress region of the osteotomy surface was deemed to
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improve the synostosis of the distal fragment (Kai et al., 2005). Therefore, the 25% translation and bandage fixation could improve the healing of the osteotomy fragment, avoid complication of the postoperative HV.
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The medial and lateral sesamoid as components of the first ray play an important role in
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maintaining the function of the metatarsophalangeal joint (Goldberg et al., 2017). The medial sesamoid in HV deformity would shift toward the lateral crista of metatarsal head (Goldberg et al., 2017;
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Kuwano et al., 2002). The medial and lateral imbalance of the first ray would result in hallux rigidus, rheumatoid arthritis, neuromuscular instability (Ella et al., 2016). As the deformity progresses, the sesamoid translation was increased by action of the muscular and ligamentous force (Heizmann et al.,
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2012). Whereas the relative reduced displacement of sesamoid (Fig.8b) could decrease instability of the first ray. Especially the sesamoid movement of postoperative HV mainly occurred in sagittal axis direction contrast to preoperative displacement (1.43mm) of vertical axis (Table.3). It was illustrated
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that the main loading behavior of sesamoid was shifted toward the tangential direction of plantar foot.
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The biomechanical behavior of sesamoid was more advantageous to heeling of the osteotomy surface (Jeon et al., 2004; Brantingham et al., 2012; Goldberg et al., 2017). It could also stimulate the functional reconstruction of postoperative soft tissue (Heizmann et al., 2012; Heizmann et al., 2012;
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Jeon et al., 2004). From the FE prediction, the greater peak stress (6.29MPa) of sesamoid in postoperative HV increased by 104% compared with the 3.084MPa of pre-operation. The stress region
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was also redistributed to the medial and lateral sesamoid (Fig.8a). To some extent, the sesamoid disorder was indirectly corrected to drive action of soft tissues (Smith et al., 1994). The stress redistribution of the metatarsal, sesamoid and plantar pressure (Fig.5-7) had validated this minimally invasive treatment of HV deformity (Sun et al., 2010; Wen et al., 2002). Hence, the operative method would improve the biomechanical function of the first ray. Except for the deformity of sesamoid, the internal ligaments disorder of the first ray would slip off the sesamoid apparatus and metatarsal bones (Goldberg et al., 2017; John et al., 2003). This affected the instability of the first metatarsophalangeal joint (Easley et al., 2007; Daniel et al., 2008). From the FE prediction, the strain of postoperative PF decreased by 49.7% compared with the value of preoperative HV (Fig.8). This would avoid the plantar fasciitis of postoperative HV (Guo et al., 2015).
ACCEPTED MANUSCRIPT The strain increase of Tib-CalL, Tib-NavL, Cal-NavL and DCun-NavL (Fig.8) indicated that the function of ligaments could keep tethered in position of the first metatarsophalangeal joint (Guo et al., 2016; Goldberg et al., 2017). In addition, the redistribution of plantar pressure (Fig.5) and the medial sesamoid (Fig.7a) may result from the action of the internal ligaments. It was illustrated that the distal osteotomy method would optimize the HV surgery (Migues et al., 2007). The present FE models as a numerical method showed the following limitations. Firstly, the first
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metatarsal bone of postoperative HV was shorter than the original length. However, the value was negligible for the prediction results. Secondly, about half of weight on the only one foot for the hallux valgus patient was debatable. Thirdly, the function of muscles around the first metatarsal was inactive
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in balanced standing (Iida et al., 1974). Therefore, the muscle behavior was neglected in two FE
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models.
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5. Conclusion
In this study, two comprehensive pre-/postoperative FE models of hallux valgus were developed to investigate the biomechanical responses of the first ray. We illuminated the availability of the distal
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osteotomy of hallux valgus. The findings showed that the distal osteotomy with bandage fixation would be more beneficial to stability of the first ray and the postoperative healing. This would effectively avoid the complication of postoperative hallux valgus and optimize the surgical approach.
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Acknowledgments
This project was supported by the grants from National Natural Science Foundation of China (Nos. 11572029, 11120101001, 11421202 and 11702068) and the Ministry of Science and Technology of
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China (2016YFB1101101)
ACCEPTED MANUSCRIPT References [1]. Heizmann, V., Capanni, F., Engleder, T., Appelt, A., 2012. Development of an Extraosseous Nitinol Implant for the Hallux Valgus Treatment: Preliminary Mechanical Investigations, Design and Numerical Simulation. Biomed Tech. 57(SI-1 Track-S), 918-921. [2]. Matzaroglou, C., Bougas, P., Panagiotopoulos, E., Saridis, A., Karanikolas, M., Kouzoudis, D., 2010. Ninety-degree chevron osteotomy for correction of hallux valgus deformity: clinical data and finite element analysis. Open Ortho J. 4, 152-156. [3]. Robinson, A. H., Limbers, J. P., 2005. Modern concepts in the treatment of hallux valgus. J Bone Joint Surg BV. 87, 1038-1045.
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[4]. Easley, M. E., Trnka, H. J., 2007. Current concepts review: hallux valgus part 1: pathome-chanics, clinical assessment, and nonoperative management. Foot ankle int. 28, 654-659.
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[5]. Daniel, E. M,, James, L. B., 2008. Increased displacement maximizes the utility of the distal chevron osteotomy for hallux valgus deformity correction. Foot ankle int. 29(2), 155-163.
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[6]. Tang, S. F., Chen, C. P., Pan, J. L., Chen, J. L., Leong, C. P., Chu, N. K., 2002. The effects of a new foot toe orthosis in treating painful hallux valgus. Arch Phys Med Rehab. 83(12), 1792-1795. [7]. Wu, G. B., Yang, Y. F., Yu, G. R., Li, B., 2014. Comment on Giannini et al. A minimally invasive
NU
technique for surgical treatment of hallux valgus: simple, effective, rapid, inexpensive (SERI). Int orthop. 38(3), 671-667.
[8]. Jeon, M. Y., Jeong, H. C., Jeong, M. S., 2004. Effects of taping therapy on the deformed angle of
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the foot and pain in hallux valgus patients. J Korean Acad Nurs. 34(5), 685-692. [9]. Bek, N., Krkl, B., 2002. Comparison of different conservative treatment approaches in patients with hallux valgus. Eklem Hast Cerrahisi. 13(2), 90-93. [10]. Brantingham, J. W., Guiry, S., Kretzmann, H. H., Kite, V. J., Globe, G., 2005. A pilot study of the
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efficiency of a chiropractic protocol using graded mobilization, manipulation and ice in the treatment of symptomatic hallux abductovalgus bunion. Clin Chiro. 8(3), 117-133.
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[11]. Gul, O. K., Nilgun, B., Ugur, T., 2015. Short-term effects of kinesiotaping on pain and joint alignment in conservative treatment of hallux valgus. J. Manipulative. Physiol. Ther. 38(8): 564-571.
[12]. Brantingham, J. W., Bonnefin, D., Perle, S. M., 2012. Manipulative therapy for lower extremity
CE
conditions: update of a literature review. J Manip Physiol Ther. 35(2),127-166. [13]. Migues, A., Campaner, G., Slullitel, G., Sotelano, P., Carrasco, M., Solari, G., 2007. Minimally invasive surgery in hallux valgus and digital deformities. Orthopedics. 30(7), 523-526.
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[14]. Meir, N., Hans-Jörg, T., Brent, G. P., Mark, S. M., 2002. Proximal metatarsal osteotomies: a comparative geometric analysis conducted on sawbone models. Foot ankle int. 23 (10), 938-945. [15]. Trnka, H. J., Krenn, S., Schuh, R., 2013. Minimally invasive hallux valgus surgery: a critical review of the evidence. Int orthop. 37(9), 1731-1735. [16]. Ella, H., Paul, M., Yves, T., 2016. Arthrodesis of the first metatarsophalangeal joint-A biomechanical comparison of four fixation techniques. Foot Ankle Surg. 1-7. [17]. Chen, W. M., Lee, S. J., Peter, V. S. L., 2014. The in vivo plantar soft tissue mechanical property under the metatarsal head: implications of tissues' joint-angle dependent response in foot finite element modeling. J mech behav biomed. 40, 264-274. [18]. Yasser, A., Radwan, A. M., Reda, M., 2012. Percutaneous distal metatarsal osteotomy versus distal chevron osteotomy for correction of mild-to-moderate hallux valgus deformity. Arch Orthop Trauma Surg. 132(11), 1539-1546.
ACCEPTED MANUSCRIPT [19]. Giannini, S., Faldini, C., Nanni, M., Di, M. A., Luciani, D., Vannini, F., 2013. A minimally invasive technique for surgical treatment of hallux valgus: simple, effective, rapid, inexpensive (SERI). Int Orthop. 37(9), 1805-1813. [20]. Bösch, P., Lack, W., Lintner, F., 1994. Application of Fibrin Sealant in Orthopedic Surgery. Fibrin Sealing in Surgical Nonsurgical Fields. 3-12. [21]. Sun, W. D., Wen, J. M., Hu, H. W., Sun, Y. S., Sang, Z. C., Jiang, K. W., 2010. Long term efficacy of minimal incision osteotomy for hallux abducto valgus. Orthopaedic Surger. 2(3), 223-228. [22]. Mao, R., Guo, J. C., Luo, C. Y., Fan, Y. B., Wen, J. M., Wang, L. Z., 2017. Biomechanical study on surgical fixation methods for minimally invasive treatment of hallux valgus. Med Eng Phys. 46,
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21-26.
[23]. Wen, J. M., Sang, Z. C., Lin, X. X., 2002. Clinical study of hallux valgus treated by minimal
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incision and manipulations. Orthop J China. 9(1), 26-29.
[24]. Mattos, E. D., Freitas, M. F., Milano, C., Valloto, E. J., Ninomiya, A. F., Pagnano, R. G., 2017.
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Reliability of two smartphone applications for radiographic measurements of hallux valgus angles. J Foot Ankle Surg. 56 (2), 230-233.
[25]. Guo, J. C., Wang, L. Z., Chen, W., Du, C. F., Mo, Z. J., Fan, Y. B., 2016. Parametric study of
NU
orthopedic insole of valgus foot on partial foot amputation. Comput Method Biomec. 19(8), 894-900.
[26]. Cheung, J. T., Zhang, M., An, K. N., 2004. Effects of plantar fascia stiffness on the biomechanical
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responses of the ankle-foot complex. Clin Biomech. 19(8), 839-846. [27]. Gefen, A., Megido-Ravid, M., Itzchak, Y., Arcan, M., 2000. Biomechanical analysis of the three-dimensional foot structure during gait: a basic tool for clinical applications. J Biomech Eng-T Asme. 122(6), 630-639.
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[28]. Zhang, M., Mak, A. F. T., 1999. In vivo friction properties of human skin. Prosthet Orthot Int. 23(2),135-141.
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[29]. Spyrou, L. A., Aravas, N., 2012. Muscle-driven finite element simulation of human foot movements. Comput Method Biomech. 15(9), 925-934. [30]. Athanasiou, K. A., Liu, G. T., Lavery, L. A., 1998. Biomechanical topography of human articular cartilage in the first metatarsophalangeal joint. Clin Orthop Relat R. 348, 269-281.
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[31]. Siegler, S., Block, J., Schneck, C. D., 1988. The mechanical characteristics of the collateral ligaments of the human ankle joint. Foot Ankle 8(5), 234-242. [32]. Twizell, E. H., 1983. Non-linear optimization of the material constants in Ogden’s
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stress-deformation function for incompressible isotropic elastic materials. J Aust Math Soc B. 24(4), 424-444.
[33]. Petre, M., Erdemir, A., Panoskaltsis, V. P., Spirka, T. A., Cavanagh, P. R., 2013. Optimization of nonlinear hyperelastic coefficients for foot tissues using a magnetic resonance imaging deformation experiment. J Biomech Eng. 135(6 ), 61001-61012. [34]. Kota, W., Yasutoshi, I., Daisuke, S., Atsushi, T., Takuma, K., Tomoyuki, S., Toshihiko, Y., 2017. Three-dimensional analysis of tarsal bone response to axial loading in patients with hallux valgus and normal feet. Clin Biomech BV. 42, 65-69. [35]. Pique-Vidal, C., Maled-Garcia, I., Arabi-Moreno, J., Vila, J., 2006. Radiographic angles in hallux valgus: differences between measurements made manually and with a computerized program. Foot Ankle Int. 27, 175-180. [36]. Guo, J. C., Wang, L. Z., Mo, Z. J., Chen, W., Fan, Y. B., 2015. Biomechanical analysis of suture
ACCEPTED MANUSCRIPT locations of the distal plantar fascia in partial foot. Int orthop. 39(12), 2373-2380. [37]. Chao, E. Y., Kasman, R. A., An, K. N., 1982. Rigidity and stress analyses of external fracture fixation devices-A theoretical approach. J Biomech. 15(12), 971-983. [38]. Kai, T., Wang, C. T., Wang, D. M., Wei, X., 2005. Primary analysis of the first ray using a 3-dimension finite element foot model. Conf. Proc. IEEE. Eng. Med. Biol. Soc. 3: 2946-2949 [39]. Goldberg, A., Welck, M. J.,
Singh, D., Cullen, N., 2017. Evaluation of the 1st
metatarso-sesamoid joint using standing CT-The Stanmore classification. Foot Ankle Surg. online. [40]. Kuwano, T., Nagamine, R., 2002. New radiographic analysis of sesamoid rotation in HV: comparison with conventional evaluation methods. Foot Ankle Int. 23(9), 811-817.
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[41]. Smith, R. W., Reynolds, J., 1984. HV assessment: report of research committee of american orthopaedic foot and ankle society. Foot Ankle. 5(2), 92-103.
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[42]. John, V. V., Jeffrey, C. C., Steven, R. K., John, M. S., James, L. T., Lowell, S. W., Howard, J. Z., Susan, D. C., 2003. Diagnosis and treatment of first metatarsophalangeal joint disorders. Section 4:
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Sesamoid disorders. J Foot Ankle Surg. 42(3), 143-147.
[43]. Iida, M., Basmajian, J. V., 1974. Electromyography of hallux valgus. Clin Orthop Relat R. 101,
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220-224.
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Conflict of interest statement
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There are no conflicts of interest involved in the manuscript.
ACCEPTED MANUSCRIPT Fig.1 Osteotomy method of the distal first metatarsal and X-ray image : (a) in horizontal plane and (b) sagittal plane Fig.2 HVA and IMA: (a) Preoperative HV; (b) Postoperative HV Fig.3 Five surface pressures test of the first metatarsal region
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Fig.4 Preoperative HV model: (a) foot components and mesh, (b) loading boundary.
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Postoperative HV model: (c) foot structure and mesh, (d) surface load and
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boundary
Fig.5 Plantar pressure distribution and RSscan measurement of pre-/postoperative HV
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Fig.6 Pre-/postoperative HV FE models prediction: (a) peak stress and distribution of
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the first metatarsal bone and the distal osteotomy fragment; (b) relative displacement of the first metatarsal bone
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Fig.7 Pre-/postoperative HV FE models prediction: (a) peak stress and distribution,
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(b) the relative displacement of the sesamoid
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Fig.8 Displacement values of the main ligaments in the first ray
ACCEPTED MANUSCRIPT Table.1 The five pressure values of the first metatarsal region Regions
Pressure values (MPa) 0.0246
Lateral location of the first metatarsal
0.0218
Bottom of the first metatarsal
0.0187
Top surface of the first metatarsal
0.0420
Medial location of the first metatarsal
0.0135
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Toe web space
ACCEPTED MANUSCRIPT Table.2 Material mechanical properties and element types of the FE model Component
Element type
Young’s modulus
Poisson’s
Cross-sectional
E (MPa)
ratio ٧
area (mm2)
3D-Tetrahedra
7300
0.3
—
Cartilage
3D-Tetrahedra
10
0.4
—
Ligaments
Truss
0～700
0.3
—
Soft tissue
3D-Hexahedron
Hyperelastic
—
—
Skin
3D-Tetrahedra
1.15
0.49
—
Plantar fascia
3D-Hexahedron
350
Plantar support
3D-Hexahedron
25,000 upper
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Bone
—
290.7
0.3
—
ACCEPTED MANUSCRIPT Table 3. Relative displacement of sesamoid in two FE models (mm) Anatomical Position of Foot in Three-dimensional Space
Sesamoid
Resultant
Sagittal Axis
Vertical Axis
Pre-operation
0.08
0.31
1.43
1.56
Post-operation
0.02
0.42
0.18
0.58
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Coronal Axis
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Highlights • The first ray in hallux valgus mainly contributes to instability of the joint. • To investigate biomechanical behavior of the first ray in hallux valgus. • Testing, imageology and finite element model were used. • This would guide HV operation and further postoperative rehabilitation.
Figure 1
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Figure 7
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Junchao Guo, Lizhen Wang, Rui Mao, Cheng Chang, Jianmin Wen, Yubo Fan PII: DOI: Reference:
S0268-0033(18)30225-0 doi:10.1016/j.clinbiomech.2018.06.002 JCLB 4545
To appear in:
Clinical Biomechanics
Received date: Accepted date:
26 March 2018 4 June 2018
Please cite this article as: Junchao Guo, Lizhen Wang, Rui Mao, Cheng Chang, Jianmin Wen, Yubo Fan , Biomechanical evaluation of the first ray in pre-/post-operative hallux valgus: A comparative study. Jclb (2017), doi:10.1016/j.clinbiomech.2018.06.002
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT Title page Biomechanical
evaluation
of
the
first
ray
in pre-/post-operative
hallux
valgus:
A
comparative study
Authors List: ※
※
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Junchao Guoa , Lizhen Wangb , Rui Maob, Cheng Changc, Jianmin Wenc*, Yubo Fana,b*
a, Beijing Key Laboratory of Rehabilitation Technical Aids for Old-Age Disability, Key Laboratory of
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Human Motion Analysis and Rehabilitation Technology of the Ministry of Civil Affairs, National Research Center for Rehabilitation Technical Aids, 100176 Beijing, PR China
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b, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, 100191 Beijing, PR China
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c, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China
* Corresponding author. Yubo Fan, Ph.D, Professor
School of Biological Science and Medical Engineering, Beihang University, Beijing, China *Co-corresponding author:
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Jianmin Wen, Ph.D, Professor
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E-mail: [email protected], Tel.: +86 10 8233 9428.
Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China E-mail: [email protected], Tel: +86-10-84739008
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※ Two authors contribute to the work
Word count: Main Text: 3125 Abstract: 240 Number of Figures:8
ACCEPTED MANUSCRIPT Abstract Background: Deformity of the first ray in hallux valgus patient has been deemed to mainly contribute to instability of the metatarsophalangeal joint. However, it is not clear whether the fixation of the distal osteotomy fragment and transposition of the sesamoid represent the best method for hallux valgus treatment. The aim of this study was to examine how postoperative hallux valgus osteotomy affects the
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stability of the first ray. Methods: To accurately investigate the biomechanical behavior of the first ray in pre-/postoperative
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hallux valgus patients, we described the relative displacement and stress distribution of the first
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metatarsal bone and sesamoid by imageology, test measurement and foot finite element model. Findings: Compared with the preoperative hallux valgus, the plantar pressure decreased by 47.8% and
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was redistributed on second metatarsal region. The peak stress and relative displacement of the distal osteotomy fragment increased by +55.7% and -59.9%, respectively. The movement of this component
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shifted toward the positive sagittal axis direction. In addition, the relative displacement of sesamoid decreased by 87.4% (0.18mm) in vertical axis direction and the stress was also redistributed on medial
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and lateral region. Moreover, the strain of the medial main ligament was more favorable to reconstruct
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function of the first ray.
Interpretation: The findings showed that the osteotomy method was helpful for stability of the first ray.
rehabilitation.
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This would provide the stability suggestions for postoperative hallux valgus fixation and guide further
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Keywords: Hallux valgus; Pre-/postoperative hallux valgus; The first ray; Distal osteotomy fragment
ACCEPTED MANUSCRIPT 1. Introduction Hallux valgus (HV) with an incidence rate of 2-4% of the population is a complex malposition of the first ray in foot deformities (Heizmann et al., 2012). The prevalence is up to 33% in adult (Matzaroglou et al., 2010). It is particular common for female to occur during the wearing constrictive or high heel shoes (Robinson et al., 2005). The evident deformity of the medial protrusion seriously affects the mechanotrans-duction in first metatarsophalangeal joint (Easley et al., 2007). Instability and
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pain of joint would also induce defected functionality of the first ray (Daniel et al., 2008). The complications with the callus, bunion, pain and deformity seriously affect the gait and forefoot health
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(Easley et al., 2007).
The current treatments for HV deformity mainly include the conservative management and the
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surgical intervention. The conservative managements are suitable for early HV complication such as bunions, callus (Tang et al., 2002). Nevertheless, the surgical intervention is used to the moderate or
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severe HV deformity (Wu et al., 2014).
The conservative management in early treatment is a choice for the HV correction. Especially for
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the early protrusion bunion, the orthotic devices of foot and toe spacer pads (Tang et al., 2002), the fixation taping (Jeon et al., 2004), exercise of the rehabilitation training (Bek et al., 2002) and the correction of orthotic footwear (Brantingham et al., 2005) will well correct deformities of the first ray
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and prevent the further complication of HV. The treatment methods take less cost and longer time (Gul
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et al., 2015). Unfortunately, the conservative treatment has shown the insufficient pain relief and difficult early discovery (Brantingham et al., 2012). With the more obvious of HV symptoms, the different surgical interventions are used and
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assessed by the study, such as the proximal metatarsal osteotomy, "V" type osteotomy (Matzaroglou et al., 2010; Migues et al., 2007; Meir et al., 2002; Trnka et al., 2013). These treatments could cause the negative effect and the postoperative complication (Migues et al., 2007; Trnka et al.,
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2013). For example, hallux rigidus, rheumatoid arthritis, neuromuscular instability under the different fixation technologies conditions (Ella et al., 2016); The negative effect of the redistribution load on the underlying bones, tendons and neurovascular structures (Chen et al., 2014); Arthritis and instability of the distal metatarsal fragment by the Chevron osteotomy (Meir et al., 2002); Avascular necrosis of the first metatarsal head (Yasser et al., 2012). Those reports used the different osteotomy techniques to stabilize the joint and prevent unstable migration of the distal fragment (Meir et al., 2002). It was also shown that the surgical intervention could improve muscle function and the activity of the metatarsophalangeal joint (Matzaroglou et al., 2010). However, there is no consensus on the best operative method for HV (Chen et al., 2014; Yasser et al., 2012). In recent years, the minimally invasive techniques have been reported and accepted by HV
ACCEPTED MANUSCRIPT patients (Bek et al., 2002). The minimal incision osteotomy as a significant advantage has the feature of rapid healing, low risk of complication and minimal shortening of the first metatarsal ray (Yasser et al., 2012). Compared with the evidence of the previous surgical technique (Bek et al., 2002; Brantingham et al., 2005; Migues et al., 2007; Meir et al., 2002), the minimally invasive techniques of Giannini (Giannini et al., 2013), Bösch (Bösch et al., 1994) and Wen's (Sun et al., 2010) methods are widely used to correct deformity of the first ray. However, the accurate surgery of HV such as the effect of
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wedge angle on osteotomy fragments (Giannini et al., 2013) and the effect of fixation methods on first metatarsal head (Giannini et al., 2013; Bösch et al., 1994; Sun et al., 2010; Mao et al., 2017) are still no definite unity for severe HV treatment.
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Therefore, the aim of this study is to assess the effect of the distal osteotomy method on
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postoperative HV (Fig.1) (Sun et al., 2010; Wen et al., 2002), using the experimental measurement and foot finite element model to compare the biomechanical behavior of the first ray in pre-/postoperative
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hallux valgus. 2. Materials and Methods
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2.1. Experiment testing
A female of HV patient (without any foot lesion and pathology except for HV) participated in minimally invasive treatment of the distal osteotomy. X-ray images of preoperative HV showed the
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magnitude of the hallux valgus angle (HVA) (35.62°), the first and second intermetatarsal angle (IMA)
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(20.26°) compared to the HVA (14.2°) and IMA (8.2°) of postoperative condition (Fig.2). The HVA and IMA were measured by MIMICS10.01 software (Materialise, Belgium). Pre-/postoperative plantar pressures of the subject were measured by the RSscan system (RSscan,
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Belgium). The plantar foot in system was divided into ten regions (the first toe, the second to fifth toes, the first, second, third, fourth and fifth metatarsals, midfoot, the heel medial and lateral) (Guo et al., 2016). In addition, the Tactilus 4.0 system (50HZ of the sampling frequency) with 32 test channels was
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used to measure the five surface pressures of metatarsal region by bandage fixation of "8" type during foot balance standing (Fig.3). The average values of five regions were shown in Table.1. The values were applied to boundary conditions of the following foot finite element (FE) model (Mao et al., 2017). 2.2. Foot FE model The pre-/postoperative HV FE models were acquired from CT images of the above female (26 years old; 54kg weight) during the unloaded condition. The 224 images in MIMICS were segmented to obtain the contours of bones and skin tissue. Then these components were processed by the Geomagic 12.0 software (Geomagic 12.0, NC27709, US) to form solid models. The foot models included 28 bones, 2 sesamoids, cartilages, main ligaments, Achilles's tendon, plantar soft tissue and skin.
ACCEPTED MANUSCRIPT Ligaments based on the anatomical location between the bones were defined as the truss element in ABAQUS software (ABAQUS 6.13, Simulia Inc, US). The cartilages were formed based on joint contact surface. To effectively investigate the biomechanical behavior of HV model, the forefoot bones except for the first ray was fused together by the resembling cartilaginous structure (Mao et al., 2017; Guo et al., 2016; Cheung et al., 2004). The contact relationship between the bones was defined by the relatively accurate movement. Surface-to-surface contact was used in interaction option of ABAQUS.
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All the tissues were meshed with a total of 386868 (Fig.4a) and 330977 (Fig.4c) elements. All tissues except for the plantar soft tissue were defined as linearly elastic, homogeneous and isotropic material. The elastic modulus and poisson’s ratio of bones were assigned as 7300MPa and 0.3,
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respectively (Gefen et al., 2000). A coefficient of friction of 0.6 was used for contact surfaces between
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the foot and ground (Zhang et al., 1994). Articular cartilage surfaces were defined by frictionless (Cheung et al., 2004). Plantar fascia was defined with 350MPa and the cross-sectional area of
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290.7mm2 (Spyrou et al., 2012). The mechanical properties of cartilage (Athanasiou et al., 1998) and ligaments (Siegler et al., 1988) in Table 2 are cited from the literatures. The plantar soft tissue was simulated with the strain energy function (U) of a first-order Ogden form (Twizell et al., 1983) as:
1-3
2
1
2 3 3
are the deviatoric principal stretches.
(1)
(16.45KPa) and (6.82) (Twizell et al., 1983)
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where
2
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U
are the material properties representing the hyperelastic behavior of the plantar soft tissue (Petre et al.,
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2013).
In load setting of two foot FE models in ABAQUS software, a foot loaded about a half of subject weight (54kg). 270N force as external loading was applied to plantar foot against ground. The upward
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vertically force was about 135N to simulate the equivalent force vectors at Achilles tendon (Guo et al., 2016; Cheung et al., 2004) (Fig.4b and 4d). Except for the above setting condition, five surface
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pressures of the first ray (Table 1) were used in postoperative foot FE model (Fig.4d). We used the displacement of a reference point on calcaneus surface to test the convergence of two FE models due to similar consideration for the other bones. The contact force between the calcaneus and the ground was loaded with a uniformly distribution of 0.1MPa. Ten different element amounts were compared by the pre/postoperative models, including: 404218, 398470, 386868, 371805, and 366547 elements for the preoperative model; 369924, 354228, 330977, 315820 and 301548 elements for the postoperative model. The different element amounts were tested to compare the displacements of the reference point. 404218 and 369924 element amounts were compared with the displacement of the reference point in two FE models, respectively. The displacement errors with the total model were within 1.54%. The test results showed that the total of 386868 and 330977 elements
ACCEPTED MANUSCRIPT in two models were selected based on the smallest relative error of 0.27% and 0.31%. Therefore, the element amounts (386868 and 330977) were applied to all foot FE models. 3. Results The pre-/postoperative HV FE models were validated by the results of RSscan measurement (Fig.5). Peak pressure of 0.46MPa and 0.24MPa in two FE models concentrated on the third metatarsal
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and the second metatarsal regions, respectively. The results were consistent with the RSscan measurements of the pre-/postoperative plantar pressure. Whilst the measured values of 0.41MPa and 0.18MPa were slightly lower than the FE models prediction.
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The stress distribution (Fig.6a) and the relative displacement (Fig.6b) of the first metatarsal
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bone were shown in Fig.6. Peak stress of the first metatarsal bone were 3.352MPa and 2.847MPa, respectively. Compared with the peak stress (1.063MPa) of the distal osteotomy fragment in
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preoperative HV model, the value increased up to 1.655MPa in the postoperative model (Fig.6a). The relative displacement of the first metatarsal bone decreased by 59.9% compared to the preoperative result of 1.451mm. In contrast to the positive vertical axis direction of the preoperative first metatarsal
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bone, it shifted toward the positive sagittal axis direction in postoperative FE prediction (Fig.6b). The stress distribution (Fig.7a) and the relative displacement (Fig.7b) of the sesamoid were shown in Fig.7. Peak stress of 3.084MPa concentrated on the lateral sesamoid region in preoperative model.
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Although the peak stress of 6.29MPa was also the same location in postoperative HV, the stress region
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was redistributed into the medial sesamoid (Fig.7a). Compared with the relative displacement (1.56mm) of sesamoid, the value was decreased by 62.6% in postoperative HV (Fig.7b). The displacement decrement (87.4%) of sesamoid mainly changed in vertical axis direction (Table.3).
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The strain of the medial main ligaments in first ray was shown in Fig.8. In contrast to plantar fascia (PF), tibiocalcanean ligament (Tib-CalL), tibionavicular ligament (Tib-NavL), calcaneonavicular
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ligament (Cal-NavL), dorsal cuneonavicular ligaments (DCun-NavL), plantar cuneonavicular ligaments (PCun-NavL), dorsal tarsometatarsal ligaments (DTar-MetaL) displacement values of 1.75, 0.19, 0.21, 0.28, 0.32, 0.49 and 0.94mm in preoperative HV model, the displacement of the above ligaments increased by -49.7%, +21.0%, +99.3%, +66.1%, +34.9%, -10.9% and -46.2% in postoperative prediction, respectively (Fig.8). 4. Discussion In this study, two models were used to investigate the biomechanical behavior of the first ray. The computational models of pre-/postoperative HV were validated by the results of RSscan measurement. Plantar pressure regions of two models under full weight bearing conditions were similar to the result
ACCEPTED MANUSCRIPT of RSscan measurement. In contrast to peak pressure of the third metatarsal region (Fig.5), plantar pressure of the postoperative HV was shifted toward the second metatarsal. This result was consistent with the normal plantar pressure from the literatures (Guo et al., 2016; Cheung et al., 2004). The validated method of plantar pressure measurement was also used in many studies (Mao et al., 2017;
Guo et al., 2016; Cheung et al., 2004; Gefen et al., 2000). However, the peak pressure of FE prediction was slightly greater than the measurement value (Fig.5). Except for limitations of the material
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properties and the simplified FE model (Mao et al., 2017; Guo et al., 2016; Cheung et al., 2004; Gefen et al., 2000), this difference may result from the incomplete function of soft tissue in postoperative HV (Easley et al., 2007).
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In clinical investigation and practice, the deformity and pain of the first ray were the most
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common symptom in HV patients (Heizmann et al., 2012; Easley et al., 2007; Daniel et al., 2008). HVA and IMA in clinical study were usually used to evaluate the severity degree of HV deformity (Mattos et al., 2007). The two parameters in our test were 35.62° and 20.26°, respectively. The values were
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included in range of deformity degree (HVA≤40°and IMA≤20°) (Wu et al., 2014). Although the data was from a female measurement, the pathologic behavior of HV was unity and commonality (Bek et al.,
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2002; Brantingham et al., 2012; Migues et al., 2007; Meir et al., 2002; Yasser et al., 2012; Giannini et al., 2013; Sun et al., 2010; Mattos et al., 2007). The values were statistically significant from the study (Mattos et al., 2007). This female subject could also represent this kind of HV patients that the
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symptom was consistent with the literature reports (Mattos et al., 2007; Daniel et al., 2008; Kota et al.,
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2017). Also, it was particular common for female to have HV deformity (Robinson et al., 2005). Therefore, the foot FE models by the convergence test and validation (Fig.4) would be reliable to investigate the biomechanical behavior of the first ray.
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For minimally invasive treatment of HV, stability of the first ray was an important effect for the postoperative rehabilitation time (Meir et al., 2002; Trnka et al., 2013; Chen et al., 2014). In present
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study, the 25% translation of the distal fragment relative to the osteotomy surface was reasonable scope of 25～50% by the literatures (Pique-Vidal et al., 2006). The relative sagittal axis movement direction of the distal osteotomy fragment (Fig.6b) would increase contact of the fragment surface (Mao et al., 2017). This could accelerate the healing of bone injury or osteotomy surface (Guo et al., 2015). Furthermore, the relative displacement of the distal fragment reduced by 59.9% compared to the 1.45mm of preoperative HV (Fig.6b). It was indicated that the osteotomy method was advantageous to increase the stability of the cutting surface (Daniel et al., 2008). From the FE prediction, the peak stress (2.847MPa) of the postoperative first metatarsal bone concentrated on the osteotomy surface compared to the preoperative HV (Fig.6a). The loading case could well induce the osteocyte growth between the proximal and distal osteotomy fragment. It accelerated the coalescence of osteotomy surface (Chao et
ACCEPTED MANUSCRIPT al., 1982). This would shorten the healing time of the postoperative osteotomy fragment (Chao et al., 1982). Meanwhile, the bandage fixation could well stabilize the first ray (Jeon et al., 2004; Brantingham et al., 2012). Moreover, the peak stress (1.655MPa) of the postoperative distal fragment also increased by 55.7% contrast to 1.063MPa of the preoperative FE prediction (Fig.6a). The higher peak stress was more helpful to bone healing of the postoperative HV (Chao et al., 1982; Kai et al., 2005). It was consistent with results that the stress region of the osteotomy surface was deemed to
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improve the synostosis of the distal fragment (Kai et al., 2005). Therefore, the 25% translation and bandage fixation could improve the healing of the osteotomy fragment, avoid complication of the postoperative HV.
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The medial and lateral sesamoid as components of the first ray play an important role in
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maintaining the function of the metatarsophalangeal joint (Goldberg et al., 2017). The medial sesamoid in HV deformity would shift toward the lateral crista of metatarsal head (Goldberg et al., 2017;
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Kuwano et al., 2002). The medial and lateral imbalance of the first ray would result in hallux rigidus, rheumatoid arthritis, neuromuscular instability (Ella et al., 2016). As the deformity progresses, the sesamoid translation was increased by action of the muscular and ligamentous force (Heizmann et al.,
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2012). Whereas the relative reduced displacement of sesamoid (Fig.8b) could decrease instability of the first ray. Especially the sesamoid movement of postoperative HV mainly occurred in sagittal axis direction contrast to preoperative displacement (1.43mm) of vertical axis (Table.3). It was illustrated
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that the main loading behavior of sesamoid was shifted toward the tangential direction of plantar foot.
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The biomechanical behavior of sesamoid was more advantageous to heeling of the osteotomy surface (Jeon et al., 2004; Brantingham et al., 2012; Goldberg et al., 2017). It could also stimulate the functional reconstruction of postoperative soft tissue (Heizmann et al., 2012; Heizmann et al., 2012;
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Jeon et al., 2004). From the FE prediction, the greater peak stress (6.29MPa) of sesamoid in postoperative HV increased by 104% compared with the 3.084MPa of pre-operation. The stress region
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was also redistributed to the medial and lateral sesamoid (Fig.8a). To some extent, the sesamoid disorder was indirectly corrected to drive action of soft tissues (Smith et al., 1994). The stress redistribution of the metatarsal, sesamoid and plantar pressure (Fig.5-7) had validated this minimally invasive treatment of HV deformity (Sun et al., 2010; Wen et al., 2002). Hence, the operative method would improve the biomechanical function of the first ray. Except for the deformity of sesamoid, the internal ligaments disorder of the first ray would slip off the sesamoid apparatus and metatarsal bones (Goldberg et al., 2017; John et al., 2003). This affected the instability of the first metatarsophalangeal joint (Easley et al., 2007; Daniel et al., 2008). From the FE prediction, the strain of postoperative PF decreased by 49.7% compared with the value of preoperative HV (Fig.8). This would avoid the plantar fasciitis of postoperative HV (Guo et al., 2015).
ACCEPTED MANUSCRIPT The strain increase of Tib-CalL, Tib-NavL, Cal-NavL and DCun-NavL (Fig.8) indicated that the function of ligaments could keep tethered in position of the first metatarsophalangeal joint (Guo et al., 2016; Goldberg et al., 2017). In addition, the redistribution of plantar pressure (Fig.5) and the medial sesamoid (Fig.7a) may result from the action of the internal ligaments. It was illustrated that the distal osteotomy method would optimize the HV surgery (Migues et al., 2007). The present FE models as a numerical method showed the following limitations. Firstly, the first
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metatarsal bone of postoperative HV was shorter than the original length. However, the value was negligible for the prediction results. Secondly, about half of weight on the only one foot for the hallux valgus patient was debatable. Thirdly, the function of muscles around the first metatarsal was inactive
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in balanced standing (Iida et al., 1974). Therefore, the muscle behavior was neglected in two FE
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models.
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5. Conclusion
In this study, two comprehensive pre-/postoperative FE models of hallux valgus were developed to investigate the biomechanical responses of the first ray. We illuminated the availability of the distal
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osteotomy of hallux valgus. The findings showed that the distal osteotomy with bandage fixation would be more beneficial to stability of the first ray and the postoperative healing. This would effectively avoid the complication of postoperative hallux valgus and optimize the surgical approach.
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Acknowledgments
This project was supported by the grants from National Natural Science Foundation of China (Nos. 11572029, 11120101001, 11421202 and 11702068) and the Ministry of Science and Technology of
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China (2016YFB1101101)
ACCEPTED MANUSCRIPT References [1]. Heizmann, V., Capanni, F., Engleder, T., Appelt, A., 2012. Development of an Extraosseous Nitinol Implant for the Hallux Valgus Treatment: Preliminary Mechanical Investigations, Design and Numerical Simulation. Biomed Tech. 57(SI-1 Track-S), 918-921. [2]. Matzaroglou, C., Bougas, P., Panagiotopoulos, E., Saridis, A., Karanikolas, M., Kouzoudis, D., 2010. Ninety-degree chevron osteotomy for correction of hallux valgus deformity: clinical data and finite element analysis. Open Ortho J. 4, 152-156. [3]. Robinson, A. H., Limbers, J. P., 2005. Modern concepts in the treatment of hallux valgus. J Bone Joint Surg BV. 87, 1038-1045.
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[4]. Easley, M. E., Trnka, H. J., 2007. Current concepts review: hallux valgus part 1: pathome-chanics, clinical assessment, and nonoperative management. Foot ankle int. 28, 654-659.
RI
[5]. Daniel, E. M,, James, L. B., 2008. Increased displacement maximizes the utility of the distal chevron osteotomy for hallux valgus deformity correction. Foot ankle int. 29(2), 155-163.
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[6]. Tang, S. F., Chen, C. P., Pan, J. L., Chen, J. L., Leong, C. P., Chu, N. K., 2002. The effects of a new foot toe orthosis in treating painful hallux valgus. Arch Phys Med Rehab. 83(12), 1792-1795. [7]. Wu, G. B., Yang, Y. F., Yu, G. R., Li, B., 2014. Comment on Giannini et al. A minimally invasive
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technique for surgical treatment of hallux valgus: simple, effective, rapid, inexpensive (SERI). Int orthop. 38(3), 671-667.
[8]. Jeon, M. Y., Jeong, H. C., Jeong, M. S., 2004. Effects of taping therapy on the deformed angle of
MA
the foot and pain in hallux valgus patients. J Korean Acad Nurs. 34(5), 685-692. [9]. Bek, N., Krkl, B., 2002. Comparison of different conservative treatment approaches in patients with hallux valgus. Eklem Hast Cerrahisi. 13(2), 90-93. [10]. Brantingham, J. W., Guiry, S., Kretzmann, H. H., Kite, V. J., Globe, G., 2005. A pilot study of the
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efficiency of a chiropractic protocol using graded mobilization, manipulation and ice in the treatment of symptomatic hallux abductovalgus bunion. Clin Chiro. 8(3), 117-133.
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[11]. Gul, O. K., Nilgun, B., Ugur, T., 2015. Short-term effects of kinesiotaping on pain and joint alignment in conservative treatment of hallux valgus. J. Manipulative. Physiol. Ther. 38(8): 564-571.
[12]. Brantingham, J. W., Bonnefin, D., Perle, S. M., 2012. Manipulative therapy for lower extremity
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conditions: update of a literature review. J Manip Physiol Ther. 35(2),127-166. [13]. Migues, A., Campaner, G., Slullitel, G., Sotelano, P., Carrasco, M., Solari, G., 2007. Minimally invasive surgery in hallux valgus and digital deformities. Orthopedics. 30(7), 523-526.
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[14]. Meir, N., Hans-Jörg, T., Brent, G. P., Mark, S. M., 2002. Proximal metatarsal osteotomies: a comparative geometric analysis conducted on sawbone models. Foot ankle int. 23 (10), 938-945. [15]. Trnka, H. J., Krenn, S., Schuh, R., 2013. Minimally invasive hallux valgus surgery: a critical review of the evidence. Int orthop. 37(9), 1731-1735. [16]. Ella, H., Paul, M., Yves, T., 2016. Arthrodesis of the first metatarsophalangeal joint-A biomechanical comparison of four fixation techniques. Foot Ankle Surg. 1-7. [17]. Chen, W. M., Lee, S. J., Peter, V. S. L., 2014. The in vivo plantar soft tissue mechanical property under the metatarsal head: implications of tissues' joint-angle dependent response in foot finite element modeling. J mech behav biomed. 40, 264-274. [18]. Yasser, A., Radwan, A. M., Reda, M., 2012. Percutaneous distal metatarsal osteotomy versus distal chevron osteotomy for correction of mild-to-moderate hallux valgus deformity. Arch Orthop Trauma Surg. 132(11), 1539-1546.
ACCEPTED MANUSCRIPT [19]. Giannini, S., Faldini, C., Nanni, M., Di, M. A., Luciani, D., Vannini, F., 2013. A minimally invasive technique for surgical treatment of hallux valgus: simple, effective, rapid, inexpensive (SERI). Int Orthop. 37(9), 1805-1813. [20]. Bösch, P., Lack, W., Lintner, F., 1994. Application of Fibrin Sealant in Orthopedic Surgery. Fibrin Sealing in Surgical Nonsurgical Fields. 3-12. [21]. Sun, W. D., Wen, J. M., Hu, H. W., Sun, Y. S., Sang, Z. C., Jiang, K. W., 2010. Long term efficacy of minimal incision osteotomy for hallux abducto valgus. Orthopaedic Surger. 2(3), 223-228. [22]. Mao, R., Guo, J. C., Luo, C. Y., Fan, Y. B., Wen, J. M., Wang, L. Z., 2017. Biomechanical study on surgical fixation methods for minimally invasive treatment of hallux valgus. Med Eng Phys. 46,
PT
21-26.
[23]. Wen, J. M., Sang, Z. C., Lin, X. X., 2002. Clinical study of hallux valgus treated by minimal
RI
incision and manipulations. Orthop J China. 9(1), 26-29.
[24]. Mattos, E. D., Freitas, M. F., Milano, C., Valloto, E. J., Ninomiya, A. F., Pagnano, R. G., 2017.
SC
Reliability of two smartphone applications for radiographic measurements of hallux valgus angles. J Foot Ankle Surg. 56 (2), 230-233.
[25]. Guo, J. C., Wang, L. Z., Chen, W., Du, C. F., Mo, Z. J., Fan, Y. B., 2016. Parametric study of
NU
orthopedic insole of valgus foot on partial foot amputation. Comput Method Biomec. 19(8), 894-900.
[26]. Cheung, J. T., Zhang, M., An, K. N., 2004. Effects of plantar fascia stiffness on the biomechanical
MA
responses of the ankle-foot complex. Clin Biomech. 19(8), 839-846. [27]. Gefen, A., Megido-Ravid, M., Itzchak, Y., Arcan, M., 2000. Biomechanical analysis of the three-dimensional foot structure during gait: a basic tool for clinical applications. J Biomech Eng-T Asme. 122(6), 630-639.
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[28]. Zhang, M., Mak, A. F. T., 1999. In vivo friction properties of human skin. Prosthet Orthot Int. 23(2),135-141.
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[29]. Spyrou, L. A., Aravas, N., 2012. Muscle-driven finite element simulation of human foot movements. Comput Method Biomech. 15(9), 925-934. [30]. Athanasiou, K. A., Liu, G. T., Lavery, L. A., 1998. Biomechanical topography of human articular cartilage in the first metatarsophalangeal joint. Clin Orthop Relat R. 348, 269-281.
CE
[31]. Siegler, S., Block, J., Schneck, C. D., 1988. The mechanical characteristics of the collateral ligaments of the human ankle joint. Foot Ankle 8(5), 234-242. [32]. Twizell, E. H., 1983. Non-linear optimization of the material constants in Ogden’s
AC
stress-deformation function for incompressible isotropic elastic materials. J Aust Math Soc B. 24(4), 424-444.
[33]. Petre, M., Erdemir, A., Panoskaltsis, V. P., Spirka, T. A., Cavanagh, P. R., 2013. Optimization of nonlinear hyperelastic coefficients for foot tissues using a magnetic resonance imaging deformation experiment. J Biomech Eng. 135(6 ), 61001-61012. [34]. Kota, W., Yasutoshi, I., Daisuke, S., Atsushi, T., Takuma, K., Tomoyuki, S., Toshihiko, Y., 2017. Three-dimensional analysis of tarsal bone response to axial loading in patients with hallux valgus and normal feet. Clin Biomech BV. 42, 65-69. [35]. Pique-Vidal, C., Maled-Garcia, I., Arabi-Moreno, J., Vila, J., 2006. Radiographic angles in hallux valgus: differences between measurements made manually and with a computerized program. Foot Ankle Int. 27, 175-180. [36]. Guo, J. C., Wang, L. Z., Mo, Z. J., Chen, W., Fan, Y. B., 2015. Biomechanical analysis of suture
ACCEPTED MANUSCRIPT locations of the distal plantar fascia in partial foot. Int orthop. 39(12), 2373-2380. [37]. Chao, E. Y., Kasman, R. A., An, K. N., 1982. Rigidity and stress analyses of external fracture fixation devices-A theoretical approach. J Biomech. 15(12), 971-983. [38]. Kai, T., Wang, C. T., Wang, D. M., Wei, X., 2005. Primary analysis of the first ray using a 3-dimension finite element foot model. Conf. Proc. IEEE. Eng. Med. Biol. Soc. 3: 2946-2949 [39]. Goldberg, A., Welck, M. J.,
Singh, D., Cullen, N., 2017. Evaluation of the 1st
metatarso-sesamoid joint using standing CT-The Stanmore classification. Foot Ankle Surg. online. [40]. Kuwano, T., Nagamine, R., 2002. New radiographic analysis of sesamoid rotation in HV: comparison with conventional evaluation methods. Foot Ankle Int. 23(9), 811-817.
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[41]. Smith, R. W., Reynolds, J., 1984. HV assessment: report of research committee of american orthopaedic foot and ankle society. Foot Ankle. 5(2), 92-103.
RI
[42]. John, V. V., Jeffrey, C. C., Steven, R. K., John, M. S., James, L. T., Lowell, S. W., Howard, J. Z., Susan, D. C., 2003. Diagnosis and treatment of first metatarsophalangeal joint disorders. Section 4:
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Sesamoid disorders. J Foot Ankle Surg. 42(3), 143-147.
[43]. Iida, M., Basmajian, J. V., 1974. Electromyography of hallux valgus. Clin Orthop Relat R. 101,
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220-224.
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Conflict of interest statement
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There are no conflicts of interest involved in the manuscript.
ACCEPTED MANUSCRIPT Fig.1 Osteotomy method of the distal first metatarsal and X-ray image : (a) in horizontal plane and (b) sagittal plane Fig.2 HVA and IMA: (a) Preoperative HV; (b) Postoperative HV Fig.3 Five surface pressures test of the first metatarsal region
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Fig.4 Preoperative HV model: (a) foot components and mesh, (b) loading boundary.
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Postoperative HV model: (c) foot structure and mesh, (d) surface load and
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Fig.5 Plantar pressure distribution and RSscan measurement of pre-/postoperative HV
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Fig.6 Pre-/postoperative HV FE models prediction: (a) peak stress and distribution of
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the first metatarsal bone and the distal osteotomy fragment; (b) relative displacement of the first metatarsal bone
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Fig.7 Pre-/postoperative HV FE models prediction: (a) peak stress and distribution,
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(b) the relative displacement of the sesamoid
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Fig.8 Displacement values of the main ligaments in the first ray
ACCEPTED MANUSCRIPT Table.1 The five pressure values of the first metatarsal region Regions
Pressure values (MPa) 0.0246
Lateral location of the first metatarsal
0.0218
Bottom of the first metatarsal
0.0187
Top surface of the first metatarsal
0.0420
Medial location of the first metatarsal
0.0135
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Toe web space
ACCEPTED MANUSCRIPT Table.2 Material mechanical properties and element types of the FE model Component
Element type
Young’s modulus
Poisson’s
Cross-sectional
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ratio ٧
area (mm2)
3D-Tetrahedra
7300
0.3
—
Cartilage
3D-Tetrahedra
10
0.4
—
Ligaments
Truss
0～700
0.3
—
Soft tissue
3D-Hexahedron
Hyperelastic
—
—
Skin
3D-Tetrahedra
1.15
0.49
—
Plantar fascia
3D-Hexahedron
350
Plantar support
3D-Hexahedron
25,000 upper
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Bone
—
290.7
0.3
—
ACCEPTED MANUSCRIPT Table 3. Relative displacement of sesamoid in two FE models (mm) Anatomical Position of Foot in Three-dimensional Space
Sesamoid
Resultant
Sagittal Axis
Vertical Axis
Pre-operation
0.08
0.31
1.43
1.56
Post-operation
0.02
0.42
0.18
0.58
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Coronal Axis
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Highlights • The first ray in hallux valgus mainly contributes to instability of the joint. • To investigate biomechanical behavior of the first ray in hallux valgus. • Testing, imageology and finite element model were used. • This would guide HV operation and further postoperative rehabilitation.
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