scholarly journals Patient-Specific 3-Dimensional Printing Titanium Implant Biomechanical Evaluation for Complex Distal Femoral Open Fracture Reconstruction with Segmental Large Bone Defect: A Nonlinear Finite Element Analysis

2020 ◽  
Vol 10 (12) ◽  
pp. 4098
Author(s):  
Kin Weng Wong ◽  
Chung Da Wu ◽  
Chi-Sheng Chien ◽  
Cheng-Wei Lee ◽  
Tai-Hua Yang ◽  
...  
Keyword(s):  
Fracture Healing ◽  
Postoperative Period ◽  
Bone Grafting ◽  
Locking Plate ◽  
Bone Ingrowth ◽  
Titanium Implant ◽  
Patient Specific ◽  
Large Defect ◽  
Plate Removal ◽  
Lightweight Structure

This study proposes a novel titanium 3D printing patient-specific implant: a lightweight structure with enough biomechanical strength for a distal femur fracture with segmental large defect using nonlinear finite element (FE) analysis. CT scanning images were processed to identify the size and shape of a large bone defect in the right distal femur of a young patient. A novel titanium implant was designed with a proximal cylinder tube for increasing mechanical stability, proximal/distal shells for increasing bone ingrowth contact areas, and lattice mesh at the outer surface to provide space for morselized cancellous bone grafting. The implant was fixed by transverse screws at the proximal/distal host bone. A pre-contoured locking plate was applied at the lateral site to secure the whole construct. A FE model with nonlinear contact element implant-bone interfaces was constructed to perform simulations for three clinical stages under single leg standing load conditions. The three stages were the initial postoperative period, fracture healing, and post fracture healing and locking plate removal. The results showed that the maximum implant von Mises stress reached 1318 MPa at the sharp angles of the outer mesh structure, exceeding the titanium destruction value (1000 MPa) and requiring round mesh angles to decrease the stress in the initial postoperative period. Bone stress values were found decreasing all the way from the postoperative period to fracture healing and locking plate removal. The overall construct deformation value reached 4.8 mm in the postoperative period, 2.5 mm with fracture healing assisted by the locking plate, and 2.1 mm after locking plate removal. The strain value at the proximal/distal implant-bone interfaces were valuable in inducing bone grafting in the initial postoperative period. The proposed patient-specific 3D printed implant is biomechanically stable for treating distal femoral fractures with large defect. It provides excellent lightweight structure, proximal/distal bone ingrowth contact areas, and implant rounded outer lattice mesh for morselized cancellous bone grafting.

scholarly journals Evaluation of Peri-Implant Bone Grafting Around Surface-Porous Dental Implants: An In Vivo Study in a Goat Model

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3606 ◽  
Author(s):  
Fahad Alshehri ◽  
Mohammed Alshehri ◽  
Terrence Sumague ◽  
Abdurahman Niazy ◽  
John Jansen ◽  
...  
Keyword(s):  
Dental Implants ◽  
Bone Grafting ◽  
Bone Growth ◽  
Bone Ingrowth ◽  
Titanium Implant ◽  
Porous Titanium ◽  
Titanium Implants ◽  
Biomechanical Assessment ◽  
Growth Area

Dental implants with surface-porous designs have been recently developed. Clinically, peri-implant bone grafting is expected to promote early osseointegration and bone ingrowth when applied with surface-porous dental implants in challenging conditions. The aim of this study was to comparatively analyze peri-implant bone healing around solid implants and surface-porous implants with and without peri-implant bone grafting, using biomechanical and histomorphometrical assessment in a goat iliac bone model. A total of 36 implants (4.1 mm wide, 11.5 mm long) divided into three groups, solid titanium implant (STI; n = 12), porous titanium implants (PTI; n = 12) and PTI with peri-implant bone grafting using biphasic calcium phosphate granules (PTI + BCP; n = 12), were placed bilaterally in the iliac crests of six goats. The goats were sacrificed seven weeks post-operatively and then subjected to biomechanical (n = 6 per group) and histomorphometrical (n = 6 per group) assessment. The biomechanical assessment revealed no significant differences between the three types of implants. Although the peri-implant bone-area (PIBA%) measured by histomorphometry (STI: 8.63 ± 3.93%, PTI: 9.89 ± 3.69%, PTI + BCP: 9.28 ± 2.61%) was similar for the three experimental groups, the percentage of new bone growth area (BGA%) inside the porous implant portion was significantly higher (p < 0.05) in the PTI group (10.67 ± 4.61%) compared to the PTI + BCP group (6.50 ± 6.53%). These data demonstrate that peri-implant bone grafting around surface-porous dental implants does not significantly accelerate early osseointegration and bone ingrowth.

Parametric study of patient-specific femoral locking plates based on a combined musculoskeletal multibody dynamics and finite element modeling

2017 ◽  
Vol 232 (2) ◽  
pp. 114-126 ◽  
Author(s):  
Xunjian Fan ◽  
Zhenxian Chen ◽  
Zhongmin Jin ◽  
Qida Zhang ◽  
Xuan Zhang ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Fracture Healing ◽  
Multibody Dynamics ◽  
Locking Plate ◽  
Plate Thickness ◽  
Design Parameters ◽  
Patient Specific ◽  
Plate Interface ◽  
Element Modeling

A combined musculoskeletal multibody dynamics and finite element modeling was performed to investigate the effects of design parameters on the fracture-healing efficiency and the mechanical property of a patient-specific anatomically adjusted femoral locking plate. Specifically, the screw type, the thickness and material of the locking plate, the gap between two femoral fragments (fracture gap) and the distance between bone and plate (interface gap) were evaluated during a human walking. We found that the patient-specific locking plate possessed greater mechanical strength and more efficient fracture healing than the corresponding traditional plate. An optimal patient-specific femoral locking plate would consist of bicortical locking screws, Ti-6Al-4V material and 4.75-mm plate thickness with a fracture gap of 2 mm and an interface gap of 1 mm. The developed patient-specific femoral locking plate based on the patient-specific musculoskeletal mechanical environment was more beneficial to fracture rehabilitation and healing. The patient-specific design method provides an effective research platform for designing and optimizing the patient-specific femoral locking plate under realistic in vivo walking conditions, which can be extended to the design of other implants as well as to other physiological loading conditions related to various daily activities.

scholarly journals Association of Gap Healing With Angle of Correction After Opening-Wedge High Tibial Osteotomy Without Bone Grafting

2021 ◽  
Vol 9 (5) ◽  
pp. 232596712110022
Author(s):  
Hyung Jun Park ◽  
Seung-Baik Kang ◽  
Moon Jong Chang ◽  
Chong Bum Chang ◽  
Woon Hwa Jung ◽  
...  
Keyword(s):  
Bone Graft ◽  
High Tibial Osteotomy ◽  
Bone Grafting ◽  
Locking Plate ◽  
Osteotomy Site ◽  
Tibial Osteotomy ◽  
Opening Wedge ◽  
Plate Removal ◽  
Correction Angle ◽  
Wedge High Tibial Osteotomy

Background: Studies have reported that opening wedge high tibial osteotomy (OWHTO) without bone grafting has outcomes that are similar to or even better than those of OWHTO with bone grafting, especially after use of a locking plate. However, a consensus on managing the gap after OWHTO has not been established. Purpose: To determine the degree of gap healing achieved without bone grafting, the factors associated with gap healing, and whether additional gap healing would be obtained after plate removal. Study Design: Cohort study; Level of evidence, 3. Methods: This retrospective study included 73 patients who underwent OWHTO without bone grafting between 2015 and 2018. Patients in the study were divided into 2 groups based on the correction angle: small correction group (<10°; SC group) and large correction group (≥10°; LC group). The locking plate used in OWHTO was removed at a mean of 13.5 months after surgery in 65 patients. Radiographic indexes were measured: gap filling height, gap vacancy ratio (GVR), and osteotomy filling index. The acceptable gap healing was defined as an osteotomy filling index ≥3. The factors related to gap healing around the osteotomy site were selected after multicollinearity analysis. Results: Although both groups achieved acceptable gap healing regardless of the correction angle, the SC group showed higher and earlier gap healing than did the LC group (gap healing rate 81.4% in the SC group vs 41.7% in the LC group at 3 months postoperatively). The GVR was 8.6% in the SC group and 15.3% in the LC group at 12 months after surgery ( P = .005). Both the amount of time that elapsed after surgery and the correction angle were associated with gap healing ( P < .05). Additional gap healing was observed after plate removal, as the GVR decreased 2.7% more in the patients with plate removal than in patients who did not have plate removal ( P = .012). Conclusion: All patients achieved acceptable gap healing without bone graft. The degree of gap healing was higher in the SC group and increased over time. Gap healing was promoted after plate removal. Considering the results of this study, a bone graft is not necessary in routine OWHTO in terms of gap healing.

Finite Element Assessment of a Porous Tibial Implant Design Using Rhombic Dodecahedron Structure

2021 ◽  
Vol 318 ◽  
pp. 71-81
Author(s):  
Basma Eltlhawy ◽  
Tawfik El-Midany ◽  
Noha Fouda ◽  
Ibrahim Eldesouky
Keyword(s):  
Finite Element ◽  
Clinical Performance ◽  
Bone Ingrowth ◽  
Maximum Shear Stress ◽  
Compressive Loading ◽  
Stress Shielding ◽  
Titanium Implant ◽  
Implant Design ◽  
Implant Fixation ◽  
Rhombic Dodecahedron

The current research presents a novel porous tibia implant design based on porous structure. The implant proximal portion was designed as a porous rhombic dodecahedron structure with 500 μm pore size. Finite element method (FEM) was used to assess the stem behavior under compressive loading compared to a solid stem model. CATIA V5R18 was used for modeling both rhombic dodecahedron and full solid models. Static structural analysis was carried out using ANSYS R18.1 to asses the implant designs. The results indicated enhanced clinical performance of tibial-knee implants compared to the solid titanium implant via increasing the maximum von-Mises stresses by 64% under the tibial tray in porous implant which reduce stress shielding. Also, the maximum shear stress developed in bone/implant interface was reduced by 68% combined with relieving the stress concentration under the stem tip to relieve patients' pain. Finally, porous implants provide cavities for bone ingrowth which improve implant fixation.

A Biomechanical Comparison of Three Miniature Locking Plate Systems in a Rabbit Radial and Ulnar Fracture Model

2019 ◽  
Vol 32 (04) ◽  
pp. 297-304 ◽  
Author(s):  
Harue Takizawa ◽  
Muneki Honnami ◽  
Takamasa Sakai ◽  
Akari Sasaki ◽  
Ayumi Sakamoto ◽  
...  
Keyword(s):  
Fracture Healing ◽  
Locking Plate ◽  
Healing Process ◽  
Biomechanical Testing ◽  
Histological Evaluation ◽  
Fracture Stabilization ◽  
Significant Difference ◽  
Ulnar Fracture ◽  
Fracture Models

Objective The aim of this study was to evaluate the biomechanical properties of three different miniature locking plate systems used to fixate radial and ulnar fractures in toy breed dogs. Implant size, shape, material and locking systems differ, and their influence on the fracture healing process is unknown. In the present study, we aimed to investigate this matter in vivo using rabbit radial and ulnar fracture models. Study Design Eighteen rabbits were randomly divided into three groups, and the left radius and ulna were osteotomized to create fracture models. The osteotomies were then fixated using either the TITAN LOCK 1.5, Fixin micro or LCP 1.5 system. Radiographs were obtained 2, 3 and 4 weeks after surgery. Four weeks after surgery, the radiuses were collected and used for biomechanical testing or histological examinations. Results During the 4 weeks of observation, no adverse effects due to the implants occurred. The radiographic scores in each group did not differ significantly at any time point. The maximum load in the LCP group was significantly higher than that in the TITAN and Fixin groups. There was no significant difference in bending stiffness or work to failure among the groups. Initial fracture healing via woven bone was evident at histological evaluation. Conclusions All three miniature locking plate systems provided adequate fracture stabilization 4 weeks after surgery, despite their differences, in rabbit models.

A rapid prototyping-based methodology for patient-specific contouring of osteotomy plates

2019 ◽  
Vol 25 (5) ◽  
pp. 888-894
Author(s):  
Behnam Gomari ◽  
Farzam Farahmand ◽  
Hassan Farkhondeh
Keyword(s):  
Rapid Prototyping ◽  
Locking Plate ◽  
Patient Specific ◽  
Osteotomy Site ◽  
Content Type ◽  
Tibial Plate ◽  
Important Challenge ◽  
Surgical Application ◽  
Bone Fragments ◽  
Plate Spring

Purpose An important challenge of the osteotomy procedures, particularly in the case of large and complex corrections, is the fixation of the osteotomy site. The purpose of this study is to propose a practical and cost-effect methodology for the plate adapting problem of osteotomy surgery. Design/methodology/approach A novel patient-specific plate contouring methodology, based on rapid prototyping (RP) and multi-point forming (MPF) techniques, was developed and evaluated. In this methodology, a female mold is fabricated by RP, based on the geometry of the osteotomy site and estimation of the plate spring back. The mold is then used to configure a MPF die, which is then used for press forming of the factory-made locking plate. The applicability of the methodology was assessed in two case studies. Findings The results of implementing the methodology on a femoral and a tibial locking plate indicated very good conformity with the underlying bone, in both the frontal and sagittal planes. The surgical application of the pre-operatively contoured tibial plate facilitated the plate locating and screw inserting procedures, and provided a secure fixation for bone fragments. Practical implications The results are promising and provide a proof of concept for the feasibility and applicability of the proposed methodology in clinical practice, as a complementary to the existing surgical preplanning and patient-specific instrument preparations. Originality/value The advantageous features of RP and the MPF were used to provide a solution for the plate adapting problem of osteotomy surgery.

scholarly journals Constructing the toolbox: Patient-specific genetic factors of altered fracture healing

2014 ◽  
Vol 1 (2) ◽  
pp. 140-148 ◽  
Author(s):  
Hicham Drissi ◽  
David N. Paglia ◽  
Farhang Alaee ◽  
Ryu Yoshida
Keyword(s):  
Fracture Healing ◽  
Genetic Factors ◽  
Patient Specific

Different effects of mechanical vibration on bone ingrowth into porous hydroxyapatite and fracture healing in a rabbit model

1989 ◽  
Vol 7 (4) ◽  
pp. 559-567 ◽  
Author(s):  
Yasuo Usui ◽  
Joseph E. Zerwekh ◽  
Heikki Vanharanta ◽  
Richard B. Ashman ◽  
Vert Mooney
Keyword(s):  
Fracture Healing ◽  
Bone Ingrowth ◽  
Mechanical Vibration ◽  
Rabbit Model ◽  
Porous Hydroxyapatite

Long-Term Study of Osteoconductivity of Bioactive Porous Titanium Metals: Effect of Sodium Removal by Dilute HCl Treatment

2008 ◽  
Vol 396-398 ◽  
pp. 353-356 ◽  
Author(s):  
Kojiro Tanaka ◽  
Mitsuru Takemoto ◽  
Shunsuke Fujibayashi ◽  
Keiichi Kawanabe ◽  
Tomiharu Matsushita ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Bone Ingrowth ◽  
Titanium Implant ◽  
Sodium Titanate ◽  
Porous Titanium ◽  
Hot Water ◽  
Sodium Removal ◽  
Long Term Study ◽  
Free Treatment

In a previous study, we have reported that sodium removal by dilute hydrochloric acid (HCl) converted the sodium titanate layer on the surface of an alkali-treated porous titanium into titania with a specific structure that has better bioactivity than sodium titanate. We have shown that a porous titanium with this treatment have good osteoinductivity in soft tissue of canines. In the present study, we investigated the effect of this treatment on the osteoconductive abilities of porous bioactive titanium implant in the long term. Three types of surface treatments were applied: (a) no treatment , (b) alkali, hot water, and heat treatment ( conventional treatment: W-AH treatment), and (c) alkali, dilute HCl, hot water, and heat treatment (Na-free treatment: HCl-AH treatment). We then examined the osteoconductivity of the materials implanted in the femoral condyles of Japanese white rabbits at 6, 12, 26, and 52 weeks. The results showed that the bone ingrowth in HCl-AH porous bioactive titanium was significantly higher than in W-AH porous bioactive titanium at 52 weeks. Therefore, sodium removal has a positive effect on the osteoconductivity of the porous bioactive titanium implant in the long term.

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