The role of cannulated compression screws in the treatment of nontraumatic necrosis of the femoral head with allogeneic fibular graft: a biomechanical analysis

doi:10.21203/rs.3.rs-1878815/v1

Download PDF

Research Article

The role of cannulated compression screws in the treatment of nontraumatic necrosis of the femoral head with allogeneic fibular graft: a biomechanical analysis

https://doi.org/10.21203/rs.3.rs-1878815/v1

This work is licensed under a CC BY 4.0 License

Version 1

posted

You are reading this latest preprint version

Purpose

To explore the biomechanical effect and mechanism of cannulated compression screw in the treatment of non traumatic necrosis of femoral head with allogeneic fibula graft.

Methods

Based on the CT data of healthy adults, four groups of models were established by using finite element software: the normal group, the femoral head necrosis group, the hip preservation operation group with allogeneic fibula graft (later referred to as group A), and the hollow compression screw combined with allogeneic fibula graft (later referred to as group B). Apply 1440N, 2400N and 4200N loads to the four groups of models respectively, observe the changes of stress distribution on the surface and deep of the femoral head, internal mechanical transmission pathway in different groups under different loads, as well as the displacement of implants in the two groups of surgical models, and explore the biomechanical role and mechanism of hollow compression screws in the same kind of allogeneic fibula graft.

Results

(1) Under normal circumstances, the pressure of the femoral head surface and internal cancellous bone is mainly concentrated in the anterolateral weight-bearing area of the femoral head, and the internal stress can be well transmitted to the lower limbs through the femoral calcar, femoral neck and other parts, without obvious stress conduction barrier.(2) The closer the necrotic location is to the anterolateral column of the weight-bearing area, the stress peaks of the cartilage, cortical bone and cancellous bone on the surface of the femoral head increase significantly compared with the normal model. With the increase of load, the stress peaks of the above bones increase significantly. In type C1 and C2 necrosis, the stress transmission of femoral head and neck was abnormal, and the stress concentration occurred in the normal bone around the necrotic area.(3) Under different loads, the peak value of von Mises stress in type C1 necrotic area in group B decreased by 1.67mpa (-18.45%), 2.77mpa (-18.37%), 4.84mpa (-18.35%) respectively compared with group A. the peak value of von Mises stress in type C2 necrotic area in group B decreased by 0.05Mpa (-0.58%), 0.08mpa (-0.56%), 0.15Mpa (-0.6%) respectively compared with group A; At the same time, under different loads, the displacement distance of type C1 allogeneic fibula strips in group B decreased by 0.06mm (-8.7%), 0.1mm (-8.7%) and 0.17mm (-8.42%) respectively compared with group A. the displacement distance of type C2 allogeneic fibula strips in group B decreased by 0.01mm (-1.72%), 0.01mm (-1.03%) and 0.02mm (-1.19%) respectively compared with group A.

Conclusion

In the allogeneic fibula graft surgery, the addition of cannulated screws may have a better mechanical effect of dispersing the stress in the necrotic area and stabilizing the fibula strip, which is most significant in type C1 necrosis.

Hollow compression screw

allogeneic fibula graft

biomechanical mechanism

hip-preserving

Due to the widespread use of alcohol and steroid hormones, the incidence rate of non-traumatic femoral head necrosis is increasing all over the world[1, 2].According to relevant studies, the average age of femoral head necrosis is 36 years (20–50 years)[3]. The natural course of osteonecrosis mainly goes through four stages: necrosis repair collapse osteoarthritis[4]. Collapse is the watershed of femoral head necrosis. Once collapse occurs, hip osteoarthritis and joint replacement are inevitable. The course of necrosis of the femoral head progressed rapidly. About 80% of the patients collapsed within 1–4 years, and 87% of them needed only 2 years from collapse to total hip replacement[3, 5]. After total hip arthroplasty, young patients will have to face the disadvantages of repeated revision and joint wear, which will have a great impact on the physical, mental and economic life of patients. Therefore, based on the high incidence rate and younger characteristics of femoral head necrosis at this stage, various femoral head preservation operations have been developed to prevent the further deterioration of collapse and delay the process of femoral head collapse[6].

Allogeneic fibular graft(AFG) is an effective method to preserve the femoral head and avoid total hip replacement in the early stage of femoral head necrosis. The advantage of this operation is that it effectively overcomes the defect that the simple core decompression operation destroys the normal subcortical bone support structure of the femoral head. By implanting an allogeneic cortical bone strip at the core decompression bone tunnel, it can perform the support function similar to the normal bone, so as to achieve the purpose of preventing the subchondral fracture of the femoral head or the fracture of the femoral neck[7, 8]. However, in our clinical practice, we found that the early implanted allogeneic fibula strips sometimes could not fuse well with the bone in the head, resulting in loosening of the implants, which affected the curative effect of hip preservation. Therefore, surgeons often screw a hollow compression screw into the inside and bottom of the allogeneic fibula strip close to the implant in parallel to achieve the effect of early fixation of the allogeneic fibula strip. More importantly, surgeons believe that the inserted hollow compression screw not only has the function of early fixation of the fibula strip, but also can effectively disperse the stress of the allogeneic fibula strip, so as to better maintain the biomechanical stability of the femoral head. In most cases, need to screw in cannulated compression screws mainly depends on surgeon's experience and preference, and there is no scientific basis. At the same time, there are few studies on whether it is necessary to implant cannulated compression screws in allogeneic fibular graft surgery.

However, the scientificity of clinical practice often needs to be verified by relevant theories. In this study, finite element analysis method was used to compare the biomechanical properties of simply implanting allogeneic fibular graft surgery and hollow compression screw combined with allogeneic fibular graft surgery at different necrotic locations, providing a biomechanical basis for clinical selection of appropriate hip preservation surgery.

Classification of femoral head necrosis

According to the classification standard of the Japanese Investigation Committee (JIC), necrotic lesions are divided into four types (type A, type B, type C1 and type C2) according to the location of the relative load-bearing area of necrotic lesions[9]. Zhihui Pang believes that JIC classification is based on the positive (anterior and posterior) films of bilateral hip joints, which only reflect the necrosis range and collapse degree of the top of the femoral head and the lateral load-bearing area. Due to the limitations of body position shielding, it is impossible to distinguish the necrosis of the anterolateral load-bearing area of the femoral head. Therefore, he created frog classification based on JIC classification, that is, to observe the necrosis range and collapse degree of the anterolateral femoral head from the frog films of bilateral hip joints, The criteria of frog position typing are the same as JIC typing (type A, type B, type C1 and type C2)[10]. In JIC classification, C1 and C2 necrosis are more recommended to be treated with hip joint preservation surgery[11]. Therefore, we established C1 and C2 hip preservation models for biomechanical analysis.

Construction Of Three-dimensional Model Of Normal Hip Joint And Necrotic Femoral Head

We recruited a 27 year old healthy male volunteer with a height of 170cm and a weight of 75kg. The volunteer had no history of hip trauma, long-term drinking and hormone use. The experiment was carried out with the consent of volunteers. The scheme was approved by the local ethics committee (the composition of the ethics committee: the First Affiliated Hospital of Guangzhou University of Chinese medicine, ethics number: NO.JY【2021】127), and the written informed consent to participate in the study was obtained from the participants. During CT scanning, the volunteers were in a supine position, with bilateral anterior superior iliac spines at the same level, and both lower limbs in a neutral position with shoulder width. Using isotropic resolution thin layer scanning technology, image matrix 512 × 512, the pixel size is 1mm. The layer thickness is 1mm and the interval is zero. Image data shall be saved in DICOM format. Mimics21.0, geomagic2017 and other software were used to reconstruct acetabulum, femur, allogeneic fibula strip, hollow compression screw and other models. After constructing the three-dimensional model of the normal hip joint through the finite element analysis software, we regard the femoral head as a sphere approximately, and the necrotic area as a cone with the center of the femoral head as the midpoint, the spherical surface of the femoral head as the bottom, and the vertex angle as 60 °, so as to determine the necrotic range and volume. Using the image segmentation and movement function of solidworks2017 software, we refer the normal model to the normal frog position placement method (hip abduction 45 °, internal rotation 15 °), Simulate the frog posture of normal human body (Fig. 1a). On the "frog posture" model, use the soildworks2017 software to make a "necrotic cone" (Fig. 1b). According to the frog posture classification standard, rotate the "necrotic cone" to the C1 and C2 positions in the frog posture classification. Finally, place the model in the positive position, so as to make C1 and C2 necrotic models (Fig. 2a and Fig. 2b).

Construction of the model of fibular allograft graft and hollow compression screw combined with fibular allograft graft.

The hollow compression screw and fibula strip model were made by using the stretching function of SolidWorks software (Fig. 3). The model parameters were as follows: hollow screw (length 90mm, thread length 30mm, thread end diameter 7.3mm, non thread end diameter 5.0mm), allogeneic fibula strip (length 90mm, diameter 10mm); Then, using the intergroup assembly function of soildworks2017 software, the fibula strips were matched to the three-dimensional model of the necrotic femoral head according to the surgical operation (specific steps: 2.5cm below the greater trochanter, point to the necrotic center of the femoral head, establish a bone tunnel, and implant the fibula strips into the necrotic models at different necrotic locations according to the direction of the bone tunnel) (Fig. 4a, Fig. 4b); According to the same steps, hollow compression screws were implanted in parallel under the fibula strips along the direction of the bone tunnel, and the hollow compression screws combined with allogeneic fibula strips were made (Fig. 4c, Fig. 4d).

Assignment Of Finite Element Model And Setting Of Boundary Conditions

All models are input into anysy17.0 to generate isotropic 10 node tetrahedral elements with a mesh size of 4mm. The initial model is composed of nodes and elements. In these models, standing on one leg is a representative posture, and the sacroiliac joint and pubic symphysis of unilateral pelvis are fully constrained. This constraint is equivalent to the ground reaction force of body weight applied to the rigid body plane bound to the distal femur (Fig. 5). Based on the anatomical structure of the hip and the biomechanical properties of the soft tissue, 7 muscles of the hip were made by using the axial connection function of SoildWorks. For the setting of muscle strength, refer to relevant literature[12]: gluteus maximus = 550N, gluteus medius = 700N, gluteus minimus = 300N, tensor fascia lata = 300N, adductor longus = 560N, adductor magnus = 600N, piriformis = 500N; The hip joint model is mainly composed of cortical bone, cancellous bone, articular cartilage, necrotic bone and other elements. The hip preservation surgery model also includes hollow compression screws and allogeneic fibula strips. The material properties of these elements are isotropic. For specific material assignment, refer to the literature[13–15]: Elastic modulus of cortical bone = 15100mpa, Poisson's ratio = 0.3; Elastic modulus of cancellous bone = 445mpa, Poisson's ratio = 0.22; Elastic modulus of articular cartilage = 10.5mpa, Poisson's ratio = 0.45; Elastic modulus of necrotic bone = 124.6mpa, Poisson's ratio = 0.15; Elastic modulus of allogeneic fibula strip = 15100mpa, Poisson's ratio = 0.3; Elastic modulus of hollow compression screw = 11000, Poisson's ratio = 0.3.

Finite Element Model Analysis

Apply surface load to the contact surface of the model (that is, the loading surface is the contact surface between the cartilage surfaces of the acetabulum of the hip joint, so that the resultant force acting on the femoral head points to the ball center of the femoral head, and the resultant force direction forms an included angle of 20 ° with the long axis of the femoral shaft, so that the stress direction is close to the resultant force direction when the human body stands on one foot) and set the load steps and sub steps. The application position of the surface load in the static position of both legs and gait cycle refers to the load-bearing surface in. The applied load includes: 1440N (equivalent to the load on the femur when 60kg people stand on one foot = 2.4 times the body weight), 2400N (equivalent to the peak stress on the foot following the ground when 60kg people walk = 4 times the body weight), 4200N (equivalent to the peak stress on the toe when 60kg people walk off the ground = 7 times the body weight).

Validation of finite element model

The validity of this research model was verified by the existing pressure-sensitive film research and the contact pressure experiment of cadaveric hip joint. We will establish a normal three-dimensional finite element model of the hip joint, give the boundary constraints and material properties, and obtain the Miss stress diagram of the hip joint. If the results are similar to or similar to the previous research results, it indicates that the model is effective. The results of Brown TD's cadaver study showed that the maximum stress of the hip joint was mainly located at the contact surface between the femoral head and the acetabulum, and the overall stress distribution of the femoral head was mainly distributed at the anterolateral side of the femoral head and along the pressure bone trabecula to the femoral trochanter[13]; Hodge WA’s[16]study showed that under normal load, the maximum contact stress at acetabular side was 7.14mpa. In this study, the maximum contact stress at the acetabular side of the model is 6.1478mpa. As shown in Fig. 6a, the overall stress distribution of the femoral head of the healthy normal model is mainly shown at the anterolateral femoral head and the femoral calcar and lesser trochanter at the inner and lower femoral neck. The results of the model are similar to previous studies, which can verify the effectiveness of the model.

Analysis Of Model Results

As shown in Fig. 6a, the pressure of the femoral head surface and internal cancellous bone of the healthy normal model is mainly concentrated in the anterolateral weight-bearing area of the femoral head, and the internal stress can be well transmitted to the lower limbs through the femoral calcar, femoral neck and other parts, without obvious stress conduction barrier. When the femoral head is necrotic, the closer the necrotic location is to the anterolateral weight-bearing area, the integrity of the anterolateral area will be affected, resulting in the decrease of the mechanical properties of the cancellous bone in the weight-bearing area and the loss of the characteristics of load transmission, resulting in the abnormal stress transmission of the femoral head and neck, the stress concentration of the normal bone around the necrotic area, and the stress peak of each bone shows an obvious upward trend (Fig. 6b, Fig. 6c). Table 1 shows the von Mises stress peaks corresponding to different bone elements of the model under different loads; After hip preservation surgery, compared with the necrosis model, the models in the group of simply implanting allogeneic fibula strips (group A) and the group of implanting hollow compression screws combined with fibula strips (group B) were significantly lower than those in the group of a and B after surgical treatment. Among them, when the necrotic location occurred in type C1, the peak von Mises stress of necrotic bone decreased the most. See Table 2 and Table 3 for specific values; In addition, we further compared the displacement of allogeneic fibula strips before and after adding hollow compression screws. The data showed that under different loads, the displacement distance of allogeneic fibula strips in group B model was smaller than that in group a model. When the necrotic position was type C1, the displacement distance of allogeneic fibula strips in group B model decreased the most. See Table 4 for specific values.

Table 1

Von Mises stress peak of different bone elements in femoral head under different loads(MPa)
Type Bone element	normal
Type Bone element	cartilage	Cortical bone	Cancellous bone	cartilage	Cortical bone	Cancellous bone	Necrotic bone	cartilage	Cortical bone	Cancellous bone	Necrotic bone
1440N	0.65	25.14	5.04	3.00	24.87	5.65	10.17	2.45	34.93	11.60	9.01
2400N	1.07	41.90	8.41	5.00	41.45	9.42	16.98	4.08	58.22	19.27	15.01
4200N	1.87	73.33	14.72	8.75	72.53	16.48	29.71	7.14	101.89	33.72	26.27

Table 2

Von Mises stress peaks of different bone elements in the two groups of surgical models during C1 necrosis(MPa)
Group Bone element	GroupA				GroupB
Group Bone element	cartilage	Cortical bone	Cancellous bone	Necrotic bone	cartilage	Cortical bone	Cancellous bone	Necrotic bone
1440N	2.48	23.91	5.16	9.05	2.33	22.55	4.86	7.38
2400N	4.14	39.84	8.61	15.08	3.09	37.58	8.10	12.31
4200N	7.24	69.72	15.06	26.38	6.82	65.77	14.17	21.54
GroupA: the hip preservation operation group with allogeneic fibula graft;
GroupB:the hollow compression screw combined with allogeneic fibula graft.

Table 3

Von Mises stress peaks of different bone elements in the two groups of surgical models during C2 necrosis(MPa)
Group Bone element	GroupA				GroupB
Group Bone element	cartilage	Cortical bone	Cancellous bone	Necrotic bone	cartilage	Cortical bone	Cancellous bone	Necrotic bone
1440N	2.42	33.59	10.91	8.64	0.88	33.26	10.92	8.59
2400N	4.04	55.99	18.18	14.40	1.46	55.44	18.21	14.32
4200N	7.07	97.97	31.81	25.20	2.56	97.01	31.86	25.05

Table 4

Distribution of maximum displacement (mm) of fibula strip in two groups of operation models
Group	GroupA			GroupB
Load	1440N	2400N	4200N	1440N	2400N	4200N
C1	0.69	1.15	2.02	0.63	1.05	1.85
C2	0.58	0.97	1.69	0.57	0.96	1.67

Our research shows that, on the one hand, the implantation of hollow compression screws can fix the allogeneic fibula strips in the early stage of surgery, making the allogeneic fibula strips strong and stable. On the other hand, the hollow compression screws can help the allogeneic fibula strips reduce the stress in the necrotic area. According to our finite element modeling data, the peak von Mises stress of necrotic bone in group A and group B decreased significantly compared with that before operation at the location of type C1 and type C2 necrosis. Under different loads, the peak von Mises stress of type C1 necrotic bone in group B decreased by 1.67mpa (-18.45%), 2.77mpa (-18.37%) and 4.84mpa (-18.35%) respectively compared with group A. the peak von Mises stress of type C2 necrotic bone in group B decreased by 0.05Mpa (-0.58%), 0.08mpa (-0.56%) and 0.15Mpa (-0.6%) respectively compared with group A; At the same time, under different loads, the displacement distance of type C1 allogeneic fibula strips in group B decreased by 0.06mm (-8.7%), 0.1mm (-8.7%) and 0.17mm (-8.42%) respectively compared with group A. the displacement distance of type C2 allogeneic fibula strips in group B decreased by 0.01mm (-1.72%), 0.01mm (-1.03%) and 0.02mm (-1.19%) respectively compared with group A. Based on this data, we found an interesting phenomenon. In the two comparison indexes of von Mises stress peak in necrotic area and the maximum displacement distance of fibula strip in group A and B, when the necrotic location is type C1, the difference between the comparison indexes of the two groups is large, and when the necrotic location is type C2, the difference between the comparison indexes of the two groups is very small. After analysis, the author believes that the reason for this situation is mainly related to the loading method of the model. The loading method used in this finite element study is surface loading, which is different from point loading. The surface loading is closer to the contact between the femoral head cartilage surface and the acetabular cartilage surface in the actual situation. According to the JIC classification principle, the location of type C1 necrosis is completely within the weight-bearing area of the femoral head, while the location of type C2 necrosis partially exceeds the outer edge of the acetabulum, Therefore, during the loading process, the stress on the necrotic area and implants in the C1 model is greater than that in the C2 model. Therefore, when the C1 model is necrotic, the difference between the two groups of surgical models is greater than that in the C2 model.

In the previous biomechanical studies on the treatment of osteonecrosis of the femoral head with fibular brace, when discussing the biomechanical analysis of the treatment of osteonecrosis of the femoral head with fibular brace at different necrotic positions, the researchers did not consider the integrity of the anterolateral column and did not fix the necrotic range[6, 11, 17]. We know that the size of the necrotic range is an important factor affecting the efficacy of hip preservation surgery. Therefore, When using the model to explore the curative effect of hip salvage surgery at different necrotic locations, the reliability of the results may be higher by fixing the necrotic range and taking into account the integrity of the anterolateral column. In this study, we first placed the model according to the frog posture, intercepted a cone with a spherical surface of the femoral head as the base and a vertex angle of 60 °, then rotated the cone to the necrosis position of C1 and C2 according to JIC classification standard, and finally carried out model loading analysis.

The advantage of this model is that it not only considers the integrity of the anterolateral column, but also fixes the necrotic volume and scope, and further explores the biological performance of allogeneic fibular brace in the treatment of femoral head necrosis at different necrotic locations. At the same time, there is no clinical and biomechanical study on the insertion of hollow compression screws in allogeneic fibula support in previous studies. Therefore, there is no clear conclusion on the necessity and biomechanical properties of hollow compression screws. The results of this study show that in the allogeneic fibular graft surgery, the addition of hollow nails may have a better mechanical effect of dispersing the stress in the necrotic area and stabilizing the fibular strip, which is the most significant in type C1 necrosis.

Although this study discussed the biomechanical properties of homograft fibular brace in the treatment of femoral head necrosis under different loads and at different necrotic locations and the necessity of cannulated screws, the limitation is that this study did not build a compression bone graft model, only considered the mechanical conduction relationship between the implant and the necrotic area, and failed to dynamically simulate the mechanical properties of fibular strips in the case of fusion with compression bone graft. This is also the direction that needs further research in the future.

Conflict of interest:All authors declare that they have no conflict of interest. All authors agree to the publication of the data.

Ethics approval:The institutional review board of the First Affiliated Hospital of Guangzhou University of Chinese Medicine approved this study(NO.JY【2021】127).And All procedures were performed in accordance with the 1964 Helsinki Declaration and its later amendments or comparable ethics standards.

Competing interests:The authors declare no competing interests.

Authors contribution:Literature search: Bin Lai, Miaoxin Cai.Data extraction and

quality assessment: Bin Lai,Miaoxin ,Cai,Guowen Bai,Shaoyu Wang.Software:Bin

Lai,Miaoxin Cai.Formal analysis:Bin Lai,Miaoxin Cai,Shaoyu Wang.Validation: Bin

Lai,Miaoxin Cai,Zhihui Pang. Writing: Bin Lai,Miaoxin Cai.All authors read and

approved the final manuscript.

Funding: This work was supported by the General Project of National Natural

Science Foundation of China,NO.81774336(to PZH) in the form of covering the

consultation fees of data statistical analysis and model building.

Availability of data and materials : Please contact the corresponding author for data requests

Chan KL, Mok CC. Glucocorticoid-induced avascular bone necrosis: diagnosis and management. Open Orthop J. 2012;6:449–57.
Matsuo K, Hirohata T, Sugioka Y, Ikeda M, Fukuda A. Influence of alcohol intake, cigarette smoking, and occupational status on idiopathic osteonecrosis of the femoral head. Clin Orthop Relat Res. 1988(234):115–23.
Petek D, Hannouche D, Suva D. Osteonecrosis of the femoral head: pathophysiology and current concepts of treatment. EFORT Open Rev. 2019;4(3):85–97.
Mont MA, Zywiel MG, Marker DR, McGrath MS, Delanois RE. The natural history of untreated asymptomatic osteonecrosis of the femoral head: a systematic literature review. J Bone Joint Surg Am. 2010;92(12):2165–70.
Zhao DW, Yu M, Hu K, Wang W, Yang L, Wang BJ, et al. Prevalence of Nontraumatic Osteonecrosis of the Femoral Head and its Associated Risk Factors in the Chinese Population: Results from a Nationally Representative Survey. Chin Med J (Engl). 2015;128(21):2843–50.
Zhou G, Zhang Y, Zeng L, He W, Pang Z, Chen X, et al. Should thorough Debridement be used in Fibular Allograft with impaction bone grafting to treat Femoral Head Necrosis: a biomechanical evaluation. BMC Musculoskelet Disord. 2015;16:140.
Wang J, Wang J, Zhang K, Wang Y, Bao X. Bayesian Network Meta-Analysis of the Effectiveness of Various Interventions for Nontraumatic Osteonecrosis of the Femoral Head. Biomed Res Int. 2018;2018:2790163.
Mont MA, Salem HS, Piuzzi NS, Goodman SB, Jones LC. Nontraumatic Osteonecrosis of the Femoral Head: Where Do We Stand Today?: A 5-Year Update. J Bone Joint Surg Am. 2020;102(12):1084–99.
Sugano N, Atsumi T, Ohzono K, Kubo T, Hotokebuchi T, Takaoka K. The 2001 revised criteria for diagnosis, classification, and staging of idiopathic osteonecrosis of the femoral head. J Orthop Sci. 2002;7(5):601–5.
Tang L, Pang z, Fan Y, Li P, Ge H, Guo F, He W,Wang H. Classification of femoral head necrosis in peri collapse stage and its clinical application vaule under the guidance of Micro syndrome diffe- erentiation concept of“differentiation of stability and treament”J Trad Chin Orthop Trauma 2016;28(05):63–6
Xu J, Zhan S, Ling M, Jiang D, Hu H, Sheng J, et al. Biomechanical analysis of fibular graft techniques for nontraumatic osteonecrosis of the femoral head: a finite element analysis. Orthop Surg Res. 2020;15(1):335.
Sverdlova NS, Witzel U. Principles of determination and verification of muscle forces in the human musculoskeletal system: Muscle forces to minimise bending stress. J Biomech. 2010;43(3):387–96.
Brown TD, Hild GL. Pre-collapse stress redistributions in femoral head osteonecrosis–a three-dimensional finite element analysis. J Biomech Eng. 1983;105(2):171–6.
Brown TD, Way ME, Ferguson AB, Jr. Mechanical characteristics of bone in femoral capital aseptic necrosis. Clin Orthop Relat Res. 1981(156):240–7.
Grecu D, Pucalev I, Negru M, Tarniţă DN, Ionovici N, Diţă R. Numerical simulations of the 3D virtual model of the human hip joint, using finite element method. Rom J Morphol Embryol. 2010;51(1):151–5.
Hodge WA, Fijan RS, Carlson KL, Burgess RG, Harris WH, Mann RW. Contact pressures in the human hip joint measured in vivo. Proc Natl Acad Sci U S A. 1986;83(9):2879–83.
Floerkemeier T, Lutz A, Nackenhorst U, Thorey F, Waizy H, Windhagen H, et al. Core decompression and osteonecrosis intervention rod in osteonecrosis of the femoral head: clinical outcome and finite element analysis. Int Orthop. 2011;35(10):1461–6.

No competing interests reported.

Download PDF

Version 1

posted

You are reading this latest preprint version

The role of cannulated compression screws in the treatment of nontraumatic necrosis of the femoral head with allogeneic fibular graft: a biomechanical analysis

Status:

Version 1

Abstract

Purpose

Methods

Results

Conclusion

Figures

Introduction

Method

Classification of femoral head necrosis

Construction Of Three-dimensional Model Of Normal Hip Joint And Necrotic Femoral Head

Assignment Of Finite Element Model And Setting Of Boundary Conditions

Finite Element Model Analysis

Results

Validation of finite element model

Analysis Of Model Results

Discussion

Declarations

References

Additional Declarations

Status:

Version 1