Análise mecânica comparativa do destorque de parafusos de minipilar com um novo componente protético, juntamente com avaliação microbiológica do vedamento para implantes de plataforma Cone Morse / Comparative mechanical analysis of the untorsion of miniabutment screws with a new prosthetic component, together with microbiological evaluation of the seal for Cone Morse platform implants

A interface implante pilar (IAI) por se constituir de duas peças inevitavelmente apresentam micro lacuna (GAP), na qual pode ocorrer infiltração bacteriana, permitindo a penetração de microorganismos que colonizam na parte interna do implante levando ao acúmulo de biofilme e, podendo levar ao desenvolvimento da periimplantite. O desgaste da conexão interna do implante é algo que ocorre com frequência, muitas vezes pela fratura do parafuso e/ou, pela perda da rosca interna do implante. A ausência de informações prévias também pode gerar a necessidade da remoção do implante, devido a estas intercorrências, surge a possibilidade da criação de um novo componente para implantes para possibilitar a reabilitação protética, sem ter que passar por uma nova cirurgia de remoção e instalação do implante. O objetivo do trabalho foi mensurar o nível de afrouxamento do parafuso do pilar protético e do minipilar comparando com novo componente protéticos, na tentativa de simular o comportamento do conjunto implante/pilar/prótese. Foram utilizados vinte implantes de plataforma cone morse (CM) da DSP® com seus respectivos mini pilares, na qual foram distribuídos em 2 grupos(n=10): Grupo 1 - implante CM + mini pilar FlexCone® DSP + coroa simplificada pirâmide invertida carga aplicada 3 mm do centro da coroa. E Grupo 2 - implante CM + mini pilar novo + coroa simplificada pirâmide invertida carga aplicada 3 mm do centro da coroa. Foram realizados ciclagem mecânica com carga 133 N, durante 2x106 ciclos, com frequência 2 Hz e temperatura de 37ºC em ambos grupos. Um torquímetro digital foi usado para medir os valores de torque reverso do parafuso protético da coroa e também do pilar protético, antes e após o carregamento. Os resultados do modelo de regressão demonstraram diferenças estatisticamente significativas em função do envelhecimento comparando os grupos da coroa sobre o pilar protético (p = 0.020) e entre os grupos do pilar sobre o implante (p = 0.048), indicando que após o envelhecimento de 2.000.000 de ciclos ao longo do tempo está associado de maneira significativa a essas variáveis no contexto deste estudo. O segundo objetivo deste estudo foi avaliar in vitro a taxa de infiltração bacteriana através da IAI, entre o novo componente protético e a superfície interna do implante, juntamente foi analisado a permeabilidade do IAI para colonização bacteriana. Um total de oitenta implantes foram testados. As estruturas montadas para grupo 1 foi torqueado com 20 N/cm e do G2 foram torqueados com 45 N, ambos imersos em microtubos contendo 200 µl de saliva humana. Após 14 dias de incubação da amostra de bactéria nos implantes, foi realizada uma análise qPCR (reação da cadeia da polimerase em tempo real). O teste revelou que não houve diferenças estatisticamente significativas no crescimento bacteriana entre os grupos em qualquer um dos pontos temporais analisados. Conclui-se que o novo componente testado apresentou um destoque menor do que comparado ao mini pilar FlexCone DSP® e apresentou infiltração bacteriana no GAP da conexão implante-pilar semelhante comparado ao mini pilar original da empresa (AU)

The abutment implant interface (IAI), as it consists of two pieces, inevitably presents a micro gap (GAP), in which bacterial infiltration can occur, allowing the penetration of microorganisms that colonize in the internal part of the implant, leading to the accumulation of biofilm and, which can lead to development of peri-implantitis. Wear of the implant's internal connection is something that occurs frequently, often due to screw fracture and/or loss of the implant's internal thread. The lack of prior information can also generate the need to remove the implant, due to these complications, the possibility arises of creating a new component for implants to enable prosthetic rehabilitation, without having to undergo a new surgery to remove and install the implant. implant. The objective of the work was to measure the level of screw loosening of the prosthetic abutment and the mini-abutment compared with the new prosthetic component, in an attempt to simulate the behavior of the implant/ abutment/prosthesis set. Twenty DSP® morse cone (CM) platform implants were used with their respective mini pillars, which were distributed into 2 groups (n=10): Group 1 - CM implant + FlexCone® DSP mini pillar + simplified crown inverted pyramid load applied 3 mm from the center of the crown. And Group 2 - CM implant + new mini abutment + simplified crown inverted pyramid load applied 3 mm from the center of the crown. Mechanical cycling was carried out with a load of 133 N, for 2x106 cycles, with a frequency of 2 Hz and a temperature of 37ºC in both groups. A digital torque wrench was used to measure the reverse torque values of the prosthetic crown screw and also the prosthetic abutment, before and after loading. The results of the regression model demonstrated statistically significant differences as a function of aging comparing the crown-on-prosthetic abutment groups (p =0.020) and between the abutment-on-implant groups (p = 0.048), indicating that after aging 2,000 ,000 cycles over time is significantly associated with these variables in the context of this study. The second objective of this study was to evaluate in vitro the rate of bacterial infiltration through the IAI, between the new prosthetic component and the internal surface of the implant, together with the permeability of the IAI for bacterial colonization. A total of eighty implants were tested. The assembled structures for group 1 were torqued with 20 N/cm and G2 were torqued with 45 N, both immersed in microtubes containing 200 µl of human saliva. After 14 days of incubation of the bacteria sample in the implants, a qPCR (real-time polymerase chain reaction) analysis was performed. The test revealed that there were no statistically significant differences in bacterial growth between groups at any of the time points analyzed. It is concluded that the new component tested presented a lower impact compared to the FlexCone DSP® mini abutment and presented bacterial infiltration in the GAP of the implant-abutment connection similar to the company's original mini abutment.(AU)

Research progress on mechanical performance evaluation of artificial intervertebral disc / 生物医学工程学杂志

The mechanical properties of artificial intervertebral disc (AID) are related to long-term reliability of prosthesis. There are three testing methods involved in the mechanical performance evaluation of AID based on different tools: the testing method using mechanical simulator, specimen testing method and finite element analysis method. In this study, the testing standard, testing equipment and materials of AID were firstly introduced. Then, the present status of AID static mechanical properties test (static axial compression, static axial compression-shear), dynamic mechanical properties test (dynamic axial compression, dynamic axial compression-shear), creep and stress relaxation test, device pushout test, core pushout test, subsidence test, etc. were focused on. The experimental techniques using specimen testing method and testing results of available artificial discs were summarized. The experimental methods and research status of finite element analysis were also summarized. Finally, the research trends of AID mechanical performance evaluation were forecasted. The simulator, load, dynamic cycle, motion mode, specimen and test standard would be important research fields in the future.

An in vitro investigation and comparison of the mechanical properties of human amnion and bovine collagen membrane

Introduction: The human amnion membrane is now increasingly used in Guided Tissue Regeneration(GTR). These placental allografts have excellent biologic properties. There is limited information regarding their mechanical properties as compared to other collagen membranes used in GTR. The aim of this study was to test and compare the mechanical properties of human amnion membrane with commercially available bovine collagen. Materials and methods: After measurement of average thickness, three strips of 5×1cm were cut from both amnion and bovine collagen membranes. Mechanical testing was done in a universal testing machine. Test speed was 1mm/min with a load cell of 100N. Tensile strength, Young's modulus and elongation at break were calculated. A suture retention test was also carried out using 3x1 cm size strips. Groups were compared through the Mann-Whitney U test. Results: Average thickness of amnion membrane was 0.46mm and thickness of bovine collagen membrane was 0.37mm.Tensile strength, Young's modulus and elongation at break of amnion membrane were 0.156MPa, 0.645MPa and 17mm; and that of bovine collagen membrane were 2.94MPa, 7.42MPa and 11.00mm, respectively (p = 0.05). Maximum load which can be applied during suturing for amnion membrane was 0.104N and for bovine collagen membrane was 2.07N (p = 0.037). Conclusion: There is no statistically significant difference in terms of tensile strength, Young's modulus and elongation at break between human amnion and bovine collagen membranes.(p=0.05)Membranes can only be considered different on the maximum load which can be applied during suturing.(p=0.037) (AU)

Feasibility of finite element analysis in the application of quality inspection on implantable medical devices / 医用生物力学

For implantable medical devices, traditional mechanical property testing is achieved by mechanical testing devices, while such method is lack of pertinence during sampling of series of products, and also time consuming during experimental testing. With the complete development of finite element analysis (FEA) techniques, introducing FEA to quality supervision and inspection will become a scientific method for saving resources and time, and also improve the pertinence. In this study, the creditability of FEA in application of highest risk sample selection, failure analysis of marketed products and auxiliary optimization of fatigue test testing was verified through case study and experimental testing. The feasibility of FEA during implants inspection was illustrated. In order to ensure the accuracy and reliability of FEA in the application of implants inspection, the essentials of establishing related finite element standards were proposed.

Efeito de regimes de treinamento físico de alto impacto nas propriedades mecânicas de ossos: estudo experimental em ratas wistar / Effects of high-impact exercise training on bone mechanical proprieties: an experimental study in female wistar rats

INTRODUÇÃO: A realização de atividade física garante benefícios ao tecido ósseo uma vez que o estresse provocado pelo carregamento promove adaptações positivas em suas propriedades mecânicas, sendo sua utilização uma estratégia não farmacológica para fortalecimento ósseo. OBJETIVO: investigar o efeito de protocolos de treinamento de alto impacto com frequências semanais e períodos diferentes nas propriedades mecânicas de ossos de ratas Wistar. MÉTODOS: Foram utilizadas 54 ratas Wistar, idade média de 10 semanas, divididas em seis grupos (n = 9): GCI (grupo controle, quatro semanas, sedentário), GTI3 (treinou três vezes por semana durante quatro semanas), GTI5 (treinou cinco vezes por semana, quatro semanas), GCII (grupo controle, oito semanas, sedentário), GTII3 (treinou três vezes por semana, oito semanas) e GTII5 (treinou cinco vezes por semana, oito semanas). O protocolo de alto impacto consistiu de 10 saltos verticais por sessão. RESULTADOS: Os ossos dos animais que receberam treinamento de alto impacto com frequência semanal elevada por um período maior de tempo mostraram valores superiores de suas propriedades mecânicas força máxima e rigidez relativa quando comparados aos demais grupos. CONCLUSÃO: Os resultados indicam que a realização de um protocolo de treinamento de alto impacto na forma de saltos verticais possui efeitos positivos sobre o tecido ósseo mesmo com frequência semanal reduzida, embora a realização de uma frequência semanal maior por um período mais elevado garanta melhores resultados.

INTRODUCTION: Physical activity has well established benefits on bone mechanical proprieties and is a non-pharmacological treatment strategy of bone weakening pathologies where given loading stress promotes adaptive responses that enhance bone strengthening. OBJECTIVE: to investigate the effect of high-impact exercise training protocols with different durations and weekly frequencies on bone mechanical proprieties of female Wistar rats. METHODS: fifty-four female Wistar rats, 10 weeks old, were divided into six groups (n=9 each): GCI (four week sedentary group, control), GTI3 (trained three times per week, four weeks), GTI5 (trained five times per week, four weeks), GCII (eight week sedentary group, control), GTII3 (trained three times per week, eight weeks) and GTII5 (trained five times per week, eight weeks). The high-impact training protocol was based on the completion of 10 vertical jumps by the animals per session. RESULTS: Bone mechanical proprieties in the groups that trained with higher weekly frequency for longer periods had greater maximum strength and stiffness when compared with the animals that trained less. CONCLUSIONS: the present results indicate that performance of high-impact training protocol has beneficial effects on bone mechanical proprieties, even with low weekly frequency, suggesting hence, that for bone gain, daily work volume is not necessary; however, for greater result, daily exercise does present better outcome.

Biomechanical test in vivo on reduction fixator for treating distal radius fractures / 医用生物力学

Objective To investigate the regular pattern of traction forces during the treatment of distal radius fracture by reduction fixator with pins. Methods A self-designed pin-lock style force transducer instead of two original pin locks in the distal of reduction fixator was adopted to conduct continuous testing on six cases of unstable distal radius fracture of forearms treated by reduction fixator in vivo. The value of static traction force and the added value of traction force in fist clenching at the postoperative 1st, 5th, 14th, 21st, 28th, 35th, 42nd, 49th day, was recorded respectively. Results The maximum and minimum static traction force was 9.93 kg and 2.26 kg, respectively, with mean value of (4.93±1.79) kg. The maximum and minimum traction force increment in fist clenching was 10.40 kg and 0.13 kg, respectively, with mean value of (3.17±2.42) kg. Conclusions Larger axial forces can be generated in muscles of the forearm, by both static tension and dynamic contraction, which might be a serious negative factor in healing unstable distal radius fractures.

Underwater digital image measurement using lens sleeves / 医用生物力学

Objective To explore the mechanical testing technique suitable for biological materials under water environment. Methods Based on digital image correlation (DIC) method, the unique lens sleeves which can avoid the distortion caused by underwater photography was designed, and this technique was applied to determining mechanical properties of the fish scales. Results The experiment on translation of the water sink indicated that the use of the designed lens sleeves could effectively reduce errors for underwater measurement with high precision; the mechanical testing on fish scales showed that different regions of the fish scales had obviously different mechanical properties, but the differences induced by regions of the dehydrated fish scales were significantly reduced. Conclusions The designed lens sleeves in this study can be applied to image acquisition effectively, and determination of mechanical properties of the biological materials under water environment was achieved using DIC method.

Advances on loading methods for spinal movement in vitro / 医用生物力学

Research on biomechanical testing of the spine in vitro is crucial to advance understanding about the function of spine, spine injury, spinal degeneration, and the influence of implants on spinal disorders. Spinal biomechanics is mainly composed of two parts: loading methods for the spine and measurement for the spinal movement. The loading method has gone through a process from gradual loading to continuous loading. In this paper, current literatures on spinal biomechanics were studied and up-to-date loading methods for the spinal movement in vitro were summarized to provide some references and help for the future research on loading methods of spinal movement.

Mecânica e microbiologia de placas produzidas a partir de osso cortical bovino, conservadas em diferentes meios / Mechanic and microbiology of plates produced from bovine cortical bone, conserved in several means

Objetivou-se com este trabalho avaliar a resistência mecânica de placas ósseas produzidas a partir de osso cortical bovino, conservadas em diferentes meios, e a eficiência desses meios em inibir o crescimento de microrganismos. Foram utilizadas 168 placas confeccionadas a partir de tíbia bovina e conservadas em glicerina a 98 por cento, solução salina a 150 por cento, solução de açúcar a 300 por cento, líquido de Dakin, congeladas em N2L a -196°C, ou esterilizadas em óxido de etileno. Após reidratação em solução de cloreto de sódio a 0,9 por cento por seis horas, elas foram submetidas a ensaios mecânicos de tração, compressão, flexão e torção. Foi realizada avaliação microbiológica das placas anterior e imediatamente após a reidratação, com ou sem adição de enrofloxacina a 0,5 por cento. Não se observou diferença significativa (P<0,01 por cento) da resistência ao ponto de ruptura entre as placas conservadas nos diferentes meios, congeladas-descongeladas ou esterilizadas. Micro-organismos foram isolados das placas conservadas em solução saturada de sal, açúcar, Dakin ou congeladas em N2L, anterior e após a reidratação. Entretanto, após o uso da solução de cloreto de sódio 0,9 por cento, acrescida de enrofloxacina a 0,5 por cento, não foram isolados microrganismos. Portanto, placas de osso bovino, conservadas em solução saturada de açúcar ou sal, glicerina a 98 por cento, solução de Dakin, congeladas em N2L ou esterilizadas em óxido de etileno assemelham-se em relação à biomecânica e a reidratação com solução de cloreto de sódio a 0,9 por cento, acrescida de enrofloxacina a 0,5 por cento, é eficaz no controle do crescimento microbiano.

The objective of this study was to evaluate the mechanical strength of bone plates yielded from bovine cortical bone, conserved in different solutions, and the efficiency of these solutions in the inhibition of microorganism's growth. A hundred and sixty eight plates yielded from bovine tibiae were conserved in 98 percent glycerin, 150 percent saline solution, 300 percent sugar solution, Dakin solution, frozen in N2L at - 196°C, or sterilized in ethylene oxide gas. After rehydration in NaCl 0.9 percent solution for six hours, plates were subjected to tensile, compression, bending and twisting testing. The microbiological evaluation of bone plates was s carried out before and immediately after rehydration, with or without enrofloxacin 0.5 percent addition. There was no significant difference (P<0.01 percent) on resistance to the rupture point in plates conserved in different solutions, frozen-thawed or sterilized. Microorganisms were isolated from plates conserved in satured salt solution, sugar satured solution, Dakin solution or frozen in N2L, before and after rehydraion However, after the use of NaCl 0.9 percent solution added of enrofloxacin 0.5 percent, microorganisms were not isolated. Therefore, bovine bone plates conserved in sugar or salt satured solution, 98 percent glycerin, Dakin solution, frozen in N2L or sterilized in ethylene oxide gas present similar biomechanical tests results, and rehydrated with a solution of NaCl 0.9 percent plus enrofloxacin 0.5 percent is effective on microorganism growth control.

Application of two different pedicle screw augmentation techniques used for in vitro sheep osteoporotic vertebra model / 医用生物力学

Objective To determine the effects of the two kinds of pedicle screws with cement augmentation used for in vitro sheep osteoporotic vertebra model. Method Forty osteoporosis specimens of lumbar vertebrae demineralized by decalcification solution were complete randomly devided into four groups including Group A (only screw),Group B (whole trajectory filled with PMMA),Group C1(partial trajectory filled with PMMA) and Group C2 (partial trajectory filled with PMMA). Osteoporosis specimens from four groups were tested by bone mineral density (BMD) and observed by spiral CT and MicroCT. The maximum force and energy absorption of pedicle screw were tested. Results BMD in each group were averagely declined about 25%～30% (P>0.05), so osteoporotic vertebrae model was successfully established.Spiral CT and MicroCT showed that screw of Group B was fully surrounded by PMMA, which constituted screw PMMA-bone interface,while screw of Group C2 was partially surrounded by PMMA, which constituted partial screw-bone and partial screw PMMA-bone interface. The axial pull-out test showed that the maximum force (Fmax) and its energy absorption in Group B, C1,2 were significantly higher than those in Group A（P0.05). Conclusions Both the whole and partial pedicle screw augmentation can significantly improve the strength of pedicle screw in the context of osteoporosis. The latter not only formed a special whole interface consisting of partial “screw-bone” and partial screw-CSC-bone interface,but produced the strengthening effect equivalent to the former by increasing injection doses of PMMA.

Biomechanical study on the novel minimally invasive anterior anatomic locking plate for mid-distal humeral shaft fractures / 医用生物力学

Objective To test the mechanical properties of a self-developed novel anterior mid-distal humerus anatomic locking plate (hereinafter referred to as the new plate) and to improve its design to provide theoretical support for its clinical application. Methods Twenty intact humerus from embalmed human cadavers were obtained and used for the biomechanical test on mid-distal humeral shaft fracture models by using the new plate (group A) and 4.5 mm LC DCP（limited contact dynamic compression plate）(group B), respectively. Both groups were compared under axial compression, medial-lateral bending, medial-lateral three-point bending and external rotation torque. Results The stiffness, strength and stress shielding of the new plate for mid-distal humeral shaft fractures under four different loads were superior to those of 4.5 mm LC-DCP, and the differences were statistically significant(P<0.05). Conclusions The new plate can satisfy the requirements of physical training at early stage for fixed mid-distal humeral shaft fractures, which gives great clinical values.

Effect of different porosities on mechanical properties and ion release of porous NiTi alloy / 医用生物力学

Objective To prepare the porous NiTi alloy with good biocompatibility for jaw bone implantation and compare the amount of the nickel ion release from NiTi alloy with TiO2 or HA coatings, respectively. Methods The porous NiTi samples were fabricated by powder metallurgy and the morphological characteristics were observed by metallographic microscope and X ray dispersive spectroscopy (XRD). The elastic modulus and fracture strength of the porous NiTi samples were recorded after the compression test. By sol-gel method, TiO2 or HA coatings were obtained on the porous NiTi samples, and the amount of nickel ion release from the samples was measured at 1，3，7，15 d, respectively. Results The pores were interconnected with the pore size of 50~200 μm and ~50 μm. The porosities of porous NiTi samples ranged from (23.5±5.24)% to (38.8±1.82)%, the elastic modulus from (9.55±0.19) GPa to (4.28±0.32) GPa, the fracture strength from (133±6.75) MPa to (80.5±5.58) MPa (P0.05). Conclusions The mechanical properties of porous NiTi alloy declined with the increase of pore-forming agent and porosity. Coating treatment could effectively inhibit the release of nickel ion from the porous NiTi alloy.

Biomechanical study of compressive strength distribution on the whole spine endplates / 医用生物力学

Objective To study distributions of the compressive strength on the whole spine endplates by measuring the compressive strength at different locations of the whole spine endplates. Methods Indentation tests were performed at 49 locations in 225 bony endplates of intact human vertebrae (C3 S1) from 5 fresh male specimens to record the failure loads. Results (1) For the whole spine endplates, failure loads of the cervical and lumbar spine were found to be higher than those of the thoracic spine (P<0.01).The failure load was first decreased from C3 to C7 before increasing to T1, and then dropping through T7 and rising again from T8, reaching the maximum at L4, and dropping at L5 before increasing again at S1. (2) The failure load at inferior cervical endplates was significantly higher than that at superior endplates except at C5 and T1 (P＜0.05). (3) Within the intervertebral space, the cranial endplates had a higher yield stress than the caudal endplates except at C5/6, T12/L1 and L5/S1. (4) Failure loads were generally increased from the central to peripheral zones (P＜0.05). (5) For different angular points, failure load distributions were found among the endplates (P<0.01). (6) Distributions of the compressive strength on the endplates varied significantly within the whole spine（P<0.01）. It was found that at C3/4, the failure load at posterior was higher than that at anterior, but at C5/6, the failure load at posterior and anterior was balanced. At T1, the failure load was found to be higher at posterior again, until passing through T2 5, and at T6 L3, the failure load at anterior was higher than that at posterior, and balanced between the anterior and posterior again at L4. At L5 S1, the failure load at posterior was higher than that at anterior. Conclusions The strength distributions on the endplates varied significantly at different locations within the whole spine, which was closely correlated with the physiological curve of the spine. The failure load at inferior endplates was higher than that at superior endplates and it was increased from central to peripheral zones. Within the intervertebral space, the compressive strength at cranial endplates was higher than that at caudal endplates.

Comparison of the biomechanical stability of cannulated screw and reconstruction plate for the fixation of symphysis pubis diastasis / 医用生物力学

Objective To test the biomechanical properties of symphysis pubis diastasis fixed by cannulated screw or reconstruction plate and provide the theoretical basis for clinical practice. Method In the experiment, fifteen normal adult specimens’ pelvis along with their intact spines from L5 to the proximal 2/3 of both femora were randomly divided into three groups. The symphysis pubis, unilateral anterior sacroiliac joint and ipsilateral sacropinous and sacrotuberous ligaments were cut; the intact major pelvic ligaments and hip joints were used to simulate Tile B1 pelvic fracture model. The fixation of five hole reconstruction plate and 6.5 mm cannulated screw were applied successively to cure symphysis pubis diastasis.The pelves were loaded vertically in the testing machine with a standing posture. The loads were applied through the L5 body to a maximum of approximately 400 N, while the displacements of the symphysis pubis were recorded. Results The study showed that two fixations were able to reduce symphysis pubis gapping and restore the biomechanical stability of pelves. Under the same condition，the displacement of symphysis pubis used 3.5 mm five hole reconstruction plate with 4 cortical screws, and the displacement by using cannulated screw were (0.944±0.983)mm and (-0.03±0.378)mm respectively. There were significant differences (P<0.05) between them. Conclusions The cannulated screw is superior to 3.5 mm five hole screw in biomechanical stability. The cannulated screw has fine biomechanical properties and is able to provide the firm fixation for symphysis pubis diastasis, which fits the principles of biological osteosynthesis.

Biomechanical comparison with cervical spines of porcin, calf and human / 医用生物力学

Objective To identify whether the calf or porcine cervical spine is a suitable substitute specimen for vitro spine study by comparing the biomechanical characteristics of porcin, calf and human cervical segments. Method Twelve fresh (age: 1 year; average weight: 60-80 kg) porcine cervical spines (C0-T1) and twelve fresh (age: 1 week; average weight： 40-50 kg) calf cervical spines (C0 T1) were taken. The twelve specimens were divided into two groups. One group of six was divided into C2-C3, C4-C5, C6-C7; the other group was divided into C3-C4, C5-C6. The muscle and soft tissue of each functional segment (C2-C3, C3-C4, C4-C5, C5-C6, C6-C7) were removed, preserving the full ligament, and then each functional segment was tested respectively. The flexion/extension, axial left/right rotation, and right/left lateral bending were applied continuously on the range of motion(ROM) and neutral zone(NZ). The findings in the study were compared with the published data of human cervical spine. Results In rotating and extension/flexion of NZ, the calf and human cervical spines were relatively similar, but they were far greater than that of the porcine cervical spine. In the lateral bending, the NZ of porcine C2-C3 was 69.7% of human, the NZ of porcine C6-C7 was 60.4% of human, and other segments were far smaller than human; the calf cervical spines were different from human, except the C2-C3. In bending and extension flexion of ROM, the porcine and human cervical spines were very similar. But they were far less than the calf, approximately 50% of calf; in the rotation, C2-C3 of porcin was about 69% of human, and other segments were less than the human. The calf cervical spine was much larger than human, and the smallest gap was in C4-C5 of 3.5 °. Conclusions The C2-C3 and C6-C7 of porcin can replace the human cervical spine in nearly all biomechanical experiments on spines. The ROM of calf is bigger than human cervical, but the C2-C3 and C3-C4 of calf are similar to human in biomechanics.