Plantar soft tissue loading under the medial metatarsals in the standing diabetic foot

Diabetes mellitus (type 2) is the most frequent cause of non-traumatic lower-limb amputations. The major cause of impairment to the feet of diabetics is persistent hyperglycemia, potentially leading to peripheral neuropathy as well as to pathological changes in plantar soft tissue, which stiffen its structure and diminish its ability to effectively distribute foot-ground contact loads. In this study, a computational model of the foot structure in the standing position was utilized to evaluate stress distributions in plantar soft tissue under the medial metatarsal heads of simulated diabetic versus normal feet. The model comprises five anatomic planar cross-sections in the directions of the foot rays, which were solved for internal stresses under static ankle joint reaction (300 N) and triceps surae muscle forces (150 N) using the finite element method. Tissues were assumed to be homogenous, isotropic and elastic materials, with nonlinear stress-strain relations for the ligaments, fascia and plantar tissue. The model revealed significant tension stress concentrations (90-150 KPa) in the plantar pad of the simulated diabetic forefoot: they were four times the normal maximum stress under the first metatarsal head and almost eight times the normal maximum stress under the second metatarsal head. It was shown that with increased severity of stiffening of the plantar pad, as related to glucose-exposure, peak forefoot contact stresses may rise by 38 and 50% under the first and second metatarsal heads, respectively. The increase in averaged (von Mises) internal stresses within the plantar soft tissue is even more pronounced, and may rise by 82 and 307% for the tissue under the first and second metatarsal heads, respectively. These results, which conform to experimental data gathered over the last two decades, suggest that the process of injury in diabetic feet is very likely to initiate not on the skin surface, but in deeper tissue layers, and the tissues underlying the distal bony prominences of the medial metatarsals are the most vulnerable ones.     

基于有限元方法的全髋关节假体个体化选型分析

目的 研究ISO 7206标准对全髋关节置换术临床应用的指导意义。方法 建立肌骨数值模型,对正常行走步态进行仿真,以获得下肢的运动学和动力学参数;建立对应的全髋关节假体有限元模型,应用步态载荷进行计算,并对比ISO标准的有限元模型计算结果。结果 正常行走步态下,髋关节力分别在20%和54%步态周期出现峰值,以此作为有限元计算的步态载荷,得到20%步态周期时假体应力最大;松动模型中假体柄上最大应力大于无松动模型中假体柄上最大应力,且应力分布趋势存在差异;分析对比ISO测试和不同体重人体步态载荷下的假体最大应力,得到ISO测试中最大应力水平对应108~142 kg体重载荷下的假体最大应力。结论ISO测试中合格的假体可满足100 kg体重人体正常步态下的强度要求。     

Biomechanical study of tarsometatarsal joint fusion using finite element analysis

Complications of surgeries in foot and ankle bring patients with severe sufferings. Sufficient understanding of the internal biomechanical information such as stress distribution, contact pressure, and deformation is critical to estimate the effectiveness of surgical treatments and avoid complications. Foot and ankle is an intricate and synergetic system, and localized intervention may alter the functions to the adjacent components. The aim of this study was to estimate biomechanical effects of the TMT joint fusion using comprehensive finite element (FE) analysis. A foot and ankle model consists of 28 bones, 72 ligaments, and plantar fascia with soft tissues embracing all the segments. Kinematic information and ground reaction force during gait were obtained from motion analysis. Three gait instants namely the first peak, second peak and mid-stance were simulated in a normal foot and a foot with TMT joint fusion. It was found that contact pressure on plantar foot increased by 0.42%, 19% and 37%, respectively after TMT fusion compared with normal foot walking. Navico-cuneiform and fifth meta-cuboid joints sustained 27% and 40% increase in contact pressure at second peak, implying potential risk of joint problems such as arthritis. Von Mises stress in the second metatarsal bone increased by 22% at midstance, making it susceptible to stress fracture. This study provides biomechanical information for understanding the possible consequences of TMT joint fusion.     

Tension and bending, but not compression alone determine the functional adaptation of subchondral bone in incongruous joints

In the present study, we tested the hypothesis that tension and bending, rather than compression alone, determine the functional adaptation of subchondral bone in incongruous joints. We investigated whether tensile stresses in the subchondral bone of the humero-ulnar articulation are affected by the direction of muscle and joint forces, and whether the tensile stresses are large enough to cause microstructural adaptation, specifically a preferential alignment of the trabeculae and the subchondral collagen fibres. Using a previously validated finite element model of the human humero-ulnar joint, we calculated the contact pressure, the principal compressive and tensile stresses, and the strain energy density in the subchondral bone for various flexion angles. A bicentric (ventro-dorsal) pressure distribution was found in the joint at 30° to 120° of flexion, with contact pressures of up to between 2.5 and 3 MPa in the ventral and dorsal aspects of the ulnar joint surface, but less than 0.5 MPa in the centre. The principal tensile stress in the subchondral bone of the trochlear notch quantitatively exceeded the principal compressive stress at low flexion angles (maximum 8.2 MPa), and the distribution of subchondral strain energy density differed substantially from that of the contact stress (r=-0.72 at 30° and r=+0.58 at 90° of flexion). No important tensile stress was computed in the trochlea humeri. On contact radiography, we found sagittally orientated subarticular trabeculae in the notch, running tangential to the surface. Furthermore, we observed sagittally orientated split lines in the subchondral bone of the notch of 20 cadaver joints, suggesting a ventro-dorsal orientation of the collagen fibres. The trochlea humeri, on the other hand, did not show a preferential direction of the subchondral split lines, these findings confirming the predictions of tensile stresses in the model. We conclude that, due to the important contribution of tension to subchondral bone stress, the distribution of subchondral density cannot be directly employed for assessing the long term distribution of joint pressure at the cartilage surface. The magnitude of the tensional stress varies considerably with the direction of the muscle and joint forces, and it appears large enough to cause functional adaptation of the subchondral bone on a microstructural level.     

Analysis of human locomotion by recording sole-floor reaction forces from anatomically discrete points

Sole-floor reaction forces were recorded from five anatomically discrete points to analyze characteristics of human locomotion. Strain gauge of 14 mm diameter were firmly attached to the sole of bare-foot for recording force changes from the following five points: (1) medial process of calcaneus, (2) head of 1st metatarsal, (3) head of 3rd metatarsal, (4) head of 5th metatarsal and (5) great toe. Fifteen healthy adults were asked to walk at 2, 4, 6 and 8 km/h and to run at 8 km/h on the treadmill. Sole-floor reaction forces from 1st to 5th metatarsals show reciprocal changes during stance phase, while force from 1st metatarsal is strong 5th metatarsal shows weak reaction and vice versa. This phenomenon may be an expression of locomotor program to maintain vertical stability of the body during stance phase. There was a linear relation between walking speeds and sum of force from the five points, although sum of forces from three metatarsals did not change significantly during the walking speeds, indicating mainly calcaneus and great toe contribute to increasing walking speed. During running the sum of force from the three metatarsals increased sharply, joining the other two points to increase thrust.     

Stresses in the normal pelvis

This paper deals in the stresses in the hip bone as a result of the forces in the muscles and ligaments acting on it. The finite element method is employed and stresses during standing on one leg stance are presented. Goodman's type joint element is used to represent the thin layer of compact bone. The analysis predicts that the maximum stresses (of the order of 0.57M_B MPa) occur in the acetabulum region and the ilium is a region of comparatively low stresses. Possibly it is the first attempt to determine stresses theoretically.     

Analysis of joint force and torque for the human and non‐human ape foot during bipedal walking with implications for the evolution of the foot

The feet of apes have a different morphology from those of humans. Until now, it has merely been assumed that the morphology seen in humans must be adaptive for habitual bipedal walking, as the habitual use of bipedal walking is generally regarded as one of the most clear‐cut differences between humans and apes. This study asks simply whether human skeletal proportions do actually enhance foot performance during human‐like bipedalism, by examining the influence of foot proportions on force, torque and work in the foot joints during simulated bipedal walking. Skeletons of the common chimpanzee, orangutan, gorilla and human were represented by multi‐rigid‐body models, where the components of the foot make external contact via finite element surfaces. The models were driven by identical joint motion functions collected from experiments on human walking. Simulated contact forces between the ground and the foot were found to be reasonably comparable with measurements made during human walking using pressure‐ and force‐platforms. Joint force, torque and work in the foot were then predicted. Within the limitations of our model, the results show that during simulated human‐like bipedal walking, (1) the human and non‐human ape (NHA) feet carry similar joint forces, although the distributions of the forces differ; (2) the NHA foot incurs larger joint torques than does the human foot, although the human foot has higher values in the first tarso‐metatarsal and metatarso‐phalangeal joints, whereas the NHA foot incurs higher values in the lateral digits; and (3) total work in the metatarso‐phalangeal joints is lower in the human foot than in the NHA foot. The results indicate that human foot proportions are indeed well suited to performance in normal human walking.     

骨质疏松症患者脊柱胸腰段椎体力学稳定性变化与椎体压缩性骨折风险预测的有限元分析

目的:通过有限元分析骨质疏松症（OP）患者的脊柱胸腰段椎体在不同运动状态下椎体力学稳定性变化,与人体正常模型进行对比分析,针对椎体是否存在压缩性骨折的风险进行预测,为干预性策略标准化建立和完善提供理论和生物力学依据。方法:选择没有脊柱胸腰段椎体伤病史的健康志愿者男女各1人;选择2例住院老年OP女性患者胸腰椎CT及MRI扫描资料。建立T11~L2骨质疏松性椎体的三维有限元模型并验证有效性。在正常生理载荷分析不同运动状态下的生物力学变化,对两组模型之间椎体、关节突关节、终板、纤维环、松质骨、椎间盘、髓核的Von Mises应力及椎体最大位移进行比对分析,同时对应力云图进行比对,分析其生理与病理关节应力变化。结果:正常人体与OP患者脊柱椎体的材料属性、弹性模量、刚度、强度以及所处的力学生物学环境变化进行分析结果表明,OP患者在脊柱前屈、后伸、左右侧弯、左右旋转、轴向7种不同运动状态下与正常人体脊柱胸腰段相比较,椎体、关节突关节、椎间盘、终板、纤维环、髓核的Von Mises应力有明显降低趋势,椎体最大位移呈现增大趋势。此外本研究对OP模型的建立并非采用文献中降低正常皮质骨、松质骨、终板弹性模量的模型,而是采用临床中根据CT数据、临床症状、骨密度等明确诊断的OP患者数据,与目前文献所提供的模型数据对比,更符合临床OP患者真实的脊柱胸腰段椎体与附属结构的生物力学特性和属性变化。与正常人体模型相比较,从筋骨系统进行分析,骨与肌肉、韧带所代表的动静力变化都有明显降低,这也印证了临床真实数据的变化。结论:OP患者脊柱胸腰段椎体应力分布不均匀、应力的集中趋势导致脊柱胸腰段椎体、椎间盘、髓核、纤维环、关节突及周围附属结构应力异常变化,即骨弹性模量的异常改变、周围附属结构的束缚力下降,引起筋骨系统平衡失常和长期稳定性下降,进而增加脊柱胸腰段椎体骨折的退变过程和风险,通过有限元分析针对椎体压缩性骨折风险建立标准化预防策略,提供理论和生物力学依据。     

足弓第2与第5跖列的肌骨系有限元模型及其临床意义

目的：建立足部内侧纵弓第2跖列与外侧纵弓第5跖列的肌骨系统有限元模型,为研究跖骨应力性骨折与相关足痛症提供生物力学工具。方法：采用中国虚拟人“女性1号”CT图像和MRI图像;应用非线性有限元方法进行生物力学分析。结果：构建了包含皮质骨、松质骨、软骨、韧带、足底腱膜、肌腱、固有肌、脂肪垫、骨髓腔与骨髓窦等10种组织的第2、第5跖列的有限元模型。足弓直立时,最大von Mises应力／应变位于第2、第5跖骨骨干与基底。各种足底软组织中,足底腱膜承担着最大张拉应力,其次为足底长韧带,足底固有肌张拉应力最小。结论：有限元预测的应力应变为研究跖骨应力性骨折,足底腱膜炎引起的慢性跟骨痛,以及足弓塌陷的发生机制提供了生物力学依据。     

Stress and strain distribution in the intact canine femur: finite element analysis

Information regarding the stresses and strains in the canine femur during various activities is important for veterinary orthopaedic surgeons, engineers designing implants for dogs, and researchers of human orthopaedics who use dogs as models. Nevertheless, such information is currently unavailable. The objective of this study is to determine the stress and strain distribution in the canine femur during mid-stance, for two loading scenarios. Three-dimensional finite element models of the canine femur were created. Two loading cases were considered: the hip joint reaction force alone, and the hip joint reaction force with all muscle forces acting on the femur. Force directions and magnitudes were obtained from the literature. Analyses were performed with NASTRAN for Windows software. When all muscle forces were considered, stresses and strains were significantly reduced, peak compressive stresses were found to occur in the medial diaphysis, and peak tensile stresses occurred in the lateral diaphysis. While the canine femur seems to be loaded primarily in bending when only the hip joint reaction force is considered, the bending moment is significantly decreased when all muscle forces are considered as well. Further in vivo and in vitro experiments are needed to validate the results of the calculations described in this paper. It is expected that future studies will be carried out, in which the stress and strain distributions in femora with different types of implants and stems will be compared to those in the normal femur.     

预应力下大腿残肢站立中期时相的有限元分析

目的研究大腿截肢患者在行走过程中站立中期时相下残肢的受力情况,为建立完整的大腿接受腔测量与评估系统提供基础。方法首先根据计算机断层扫描图像三维重建大腿截肢患者的骨骼、肌肉软组织和接受腔的三维模型,考虑步行中关节角度变化进行组装。然后,建立模拟步态周期中站立中期时相受力的有限元模型,对模型进行预应力影响下非线性大变形有限元分析。结果当考虑了步行中关节角度变化和预应力的影响以后,计算所得的接触法向界面压力值最大值均位于残肢的末端部位,为257.66 kPa,与实际测量患者步行中站立中期时相下最大应力258.90 kPa符合较好。结论考虑关节角度变化、预应力和摩擦的三维模型能够更为有效地模拟患者在步行中的受力情况。     

A mathematical modelling study investigating the influence of knee joint flexion angle and extension moment on patellofemoral joint reaction force and stress

BackgroundPatellofemoral pain (PFP) is the most common orthopaedic condition among runners. Individuals with PFP exhibit greater patellofemoral joint (PFJ) reaction force and stress when compared with pain-free controls. However, it is not clear whether PFJ reaction force and stress are the highest (or lowest) when knee joint flexion angle and extension moment are in which combinations. We aimed to investigate the influence of knee joint flexion angle and extension moment on PFJ reaction force and stress.MethodsA PFJ sagittal model was used to quantify PFJ reaction force and stress. Based on the public dataset of the previous study, peak knee joint flexion angle and extension moment at various running speeds was calculated. Based on the calculated peak value, simulation ranges were set to knee joint flexion angle of 10–45° and extension moment of 0–240 Nm. The quadriceps force, effective lever arm length at quadriceps muscle, and PFJ contact area were determined as a function of the knee joint flexion angle and extension moment, and finally PFJ forces and stress were estimated.ResultsPFJ reaction force increased as the knee flexion angle and extension moment increased. Although PFJ stress also increased as the knee extension moment increased, it was at the highest and lowest at 10° and about 30° knee joint flexion angles, respectively.ConclusionsIncorporating knee flexion posture (approximately 30°) during running may help in reducing PFJ stress, which would be useful in the prevention of pain and act as an optimal treatment program for PFP.     

Clinical significance of musculoskeletal finite element model of the second and the fifth foot ray with metatarsal cavities and calcaneal sinus

Aim

The aim of this study was to establish musculoskeletal finite element (FE) model of the second and the fifth foot ray accounting for metatarsal cavities and calcaneal sinus. The model was then used to predict the effects of metatarsal cavities and calcaneal sinus on internal stresses/strains of plantar longitudinal arches.

Materials and methods

The geometry of foot bones and soft tissues were constructed by CT and MRI images of Virtual Chinese Human “female No. 1”. Two types of nonlinear FE models of sagittal foot rays were developed with or without metatarsal cavities and calcaneal sinus using ANSYS © software package. The sagittal trabecular architecture of metatarsals and calcaneus were obtained by cutting, defatting and bleaching fresh foot specimen of a cadaver.

Results

The model proposed was able to describe the isostatic stress flows in sagittal planes of plantar longitudinal arches. The size of metatarsal cavity or calcaneal sinus could affect stress/strain distributions on metatarsals and calcaneus, but had almost no effects on stress/strain of other foot bones and plantar soft tissues. During balance standing, the maximum von Mises stresses were predicted at the shaft and the basis of metatarsals, while the maximum strains of bony regions were found around metatarsal cavities. Among plantar soft tissues, relative high tensions were burdened by plantar fascia, followed by long plantar ligament. The minimum tensions occurred in plantar intrinsic muscles.

Conclusions

The study shows that the tension/compression stress flows are geometrically similar with the tension/compression trabecular architectures in sagittal sections of metatarsal and calcaneus. The FE predictions of stress/strain concentration on metatarsals and fascia are useful in enhancing biomechanical knowledge on metatarsal stress fractures and plantar fasciitis.

     

Stress distribution in the temporo-mandibular joint discs during jaw closing: a high-resolution three-dimensional finite-element model analysis

Purpose

This study aims at analysing the stresses distribution in the temporomandibular joint (TMJ) using a complete high-resolution finite element model (FE Model). This model is used here to analyse the stresses distribution in the discs during a closing jaw cycle. In the end, this model enables the prediction of the stress evolution in the TMJ disc submitted to various loadings induced by mandibular trauma, surgery or parafunction.

Materials and methods

The geometric data for the model were obtained from MRI and CT scans images of a healthy male patient. Surface and volume meshes were successively obtained using a 3D image segmentation software (AMIRA^?). Bone components of skull and mandible, both of joint discs, temporomandibular capsules and ligaments and dental arches were meshed as separate bodies. The volume meshes were transferred to the FE analysis software (FORGE^?). Material properties were assigned for each region. Boundary conditions for closing jaw simulations were represented by different load directions of jaws muscles. The von Mises stresses distribution in both joint discs during closing conditions was analyzed.

Results

The pattern of von Mises stresses in the TMJ discs is non-symmetric and changed continuously during jaw movement. Maximal stress is reached on the surface disc in areas in contact with others bodies.

Conclusions

The three-dimension finite element model of masticatory system will make it possible to simulate different conditions that appear to be important in the cascade of events leading to joint damage.     

Finite element analysis of a three-dimensional model of a proximal femur-cemented femoral THJR component construct: influence of assigned interface conditions on strain energy density

A finite element analysis of the stresses in a construct, comprising a three-dimensional model of the proximal human femur in which the stem of a total hip joint replacement was cemented, was performed. The one-legged standing condition was used, with all applied forces on the proximal femur being considered. These forces were the resultant hip joint reaction force and the forces due to the activation of the abductor, ilio-psoas, and ilio-tibialis muscles. The cortical and cancellous bones were assigned anisotropic elastic properties. It was found that the mean value of the strain energy density at each of the regions considered was considerably higher when debonding was considered at both the cancellous bone-acrylic bone cement and bone cement-stem interfaces (represented using surface-to-surface Coulomb friction, coefficient of friction = 0.22) compared to when perfect bonding conditions were taken to exist at these interfaces. The significance of this finding, together with the study limitations, is discussed.     

Posterior-anterior body weight shift during stance period studied by measuring sole-floor reaction forces during healthy and hemiplegic human walking

Posterior-anterior body weight shift during stance phase of human overground locomotion was investigated by recording sole-floor reaction force from five anatomically discrete points with strain gauge transducers of 14 mm diameter attached firmly to the sole of bare foot. At first the subject was asked to walk straight on the laboratory floor at his/her preferred velocity. Then the subject was asked to walk curved path of about 1m radius. For kicking off the body at the end of stance phase, sole-floor reaction force from 3rd metatarsal was stronger than 1st metatarsal or 5th metatarsal during the straight walking, thus body weight shift is represented from heel to 3rd metatarsal line. When walking along a curved path, two types of strategies were recognized; a group of subjects walked leaning to inner leading foot during stance period as judged by stronger forces recorded from 5th metatarsal combined with stronger force from 1st metatarsal of outer trailing foot. Another group of subjects showed almost the same patterns either in the straight and curved walking, suggesting the subjects changed direction of the foot during the immediately previous swing phase to the tangent direction of the curve and placed the foot without leaning the body weight to either direction. Hemiplegic patients showed strikingly different distribution of sole-floor reaction forces from the five points; strongest forces were recorded from 3rd and 5th metatarsals combined with reduced reaction force from heel, therefore characteristic y-vector patterns were observed.     

坐姿下不同组织压力性损伤生物力学研究

目的 探讨坐姿下臀部压力性损伤易发部位以及不同软组织的生物力学响应,为有效预防深层组织压力性损伤提供参考。 方法 基于臀部 CT 扫描数据,建立坐位臀部有限元模型,包括骨骼、肌肉、脂肪和皮肤组织及坐垫模型,利用生死单元模拟组织损伤。 对比实验坐垫界面压力测量数据与有限元模拟结果,验证模型有效性。 模拟坐位力学状态,研究软组织的应力、应变情况,分析不同软组织中的压应力及超出极限值后可能造成的损伤情况。结果 通过对比坐垫模型仿真结果与实验界面压力测量结果,证明模型有效。 坐位时坐骨结节下方软组织区域出现应力集中现象。 其中,臀大肌组织中的横向压应力峰值约为 38 kPa,剪切应力峰值约为 3. 4 MPa;而脂肪组织中的最大压应力与剪切应力峰值分别为 22 kPa 与 4. 5 MPa,均未出现在坐骨结节正下方。 结论 软组织受到一定时间和大小的压力载荷作用,可能出现深层组织损伤。 当保持坐姿一定时间后,应及时变换体位,以降低压力性损伤出现的概率。 研究结果为预防压力性损伤提供生物力学依据,具有重要的临床研究价值。     

Comparison of computational analysis with clinical measurement of stresses on below-knee residual limb in a prosthetic socket

Interface pressures and shear stresses between a below-knee residual limb and prosthetic socket predicted using finite element analyses were compared with experimental measurements. A three-dimensional nonlinear finite element model, based on actual residual geometry and incorporating PTB socket rectification and interfacial friction/slip conditions, was developed to predict the stress distribution. A system for measuring pressures and bi-axial shear stresses was used to measure the stresses in the PTB socket of a trans-tibial amputee. The FE-predicted results indicated that the peak pressure of 226 kPa occurred at the patellar tendon area and the peak shear stress of 50 kPa at the anterolateral tibia area. Quantitatively, FE-predicted pressures were 11%, on average, lower than those measured by triaxial transducers placed at all the measurement sites. Because friction/slip conditions between the residual limb and socket liner were taken into consideration by using interface elements in the FE model, the directions and magnitudes of shear stresses match well between the FE prediction and clinical measurements. The results suggest that the nonlinear mechanical properties of soft tissues and dynamic effects during gait should be addressed in future work.     

关节盘移位对颞下颌关节内应力分布的影响

目的 通过对不同关节盘移位的数值模拟,探究各种移位情况下颞下颌关节（temporomandibular joint,TMJ）内各结构的应力分布规律。方法 依据CT图像,建立包含下颌骨、全牙列、关节盘和关节软骨的正常TMJ三维有限元模型;参考关节盘前、后、外、内移位的临床特征,建立对应的4个模型。关节盘与关节软骨间考虑接触,用缆索元模拟下颌韧带和关节盘附着,施加正中咬合荷载。结果 前移位将导致关节盘中带产生过高的压应力,达到3.23 MPa;后、内、外移位时关节盘的整体应力水平比前移位和正常TMJ高;各种移位都使关节结节后斜面的应力值大幅度增加,但对髁突关节面的影响却不大。结论 各种移位都将导致关节盘和关节结节后斜面产生过高的应力,且后、内、外移位更为危险,更容易造成关节结构和功能的损伤。     

低弹性模量新型组合式锁定加压钢板固定股骨粉碎性骨折的三维有限元分析

目的 通过有限元分析的方法观察低弹性模量Ti2448的新型组合式锁定加压钢板(NALCP)固定股骨粉碎性骨折的应力分布情况。方法 采用64排螺旋CT对1名健康成年男性股骨进行层厚为5 mm(拆薄图像层厚0.625 mm)扫描,获得股骨CT数据,通过Mimics 10.0、Geomagic studio 12.0等逆向工程软件获得股骨有限元模型,模拟股骨中段粉碎性骨折,分别采用Ti-6Al-4V(普通弹性模量,为110 GPa)及Ti2448(低弹性模量,为30 GPa)两种弹性模量方案钢板模拟手术固定,加以缓慢行走单腿股骨载荷及扭转载荷,分析两种弹性模量钢板及股骨的应力分布情况。结果 两种载荷情况下,两种固定方案钢板应力分布变化趋势均匀,骨折断端周围为应力集中区域,最大应力集中点位置均位于滑槽钢板与主钢板锁定孔,两种方案主钢板应力变化不大。与Ti-6Al-4V钢板方案相比,Ti2448滑槽钢板最大应力在缓慢行走载荷和扭转载荷下分别减少了20.6%和15.2%,而骨折块轴向最大应力则分别增加了95.8%和95.7%。 结论 低弹性模量NALCP既能够为股骨干32-C2.1型骨折提供坚强的力学稳定性,又能增加骨折断端力学刺激,并能有效固定骨碎块。