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Bachmeier AT, Euler E, Bader R, Böcker W, Thaller PH. Novel approach to estimate distraction forces in distraction osteogenesis and application in the human lower leg. J Mech Behav Biomed Mater 2022; 128:105133. [PMID: 35217291 DOI: 10.1016/j.jmbbm.2022.105133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 01/18/2022] [Accepted: 02/11/2022] [Indexed: 11/19/2022]
Abstract
PURPOSE In distraction osteogenesis (DO) of long bones, new bone tissue is distracted to lengthen limbs or reconstruct bone defects. However, mechanical boundary conditions in human application such as arising forces are mainly based on limited empirical data. Our aim was the numerical determination of the callus distraction force (CDF) and the total distraction force (TDF) during DO in the tibia of adults to advance the understanding of callus tissue behavior and optimize DO procedures. METHOD We implemented a mathematical model based on an animal experiment to enable the calculation of forces arising while distracting callus tissue, excluding the influence of surrounding soft tissue (muscles, skin etc.). The CDF progression for the distraction period was calculated using the implemented model and varying distraction parameters (initial gap, area, step size, time interval, length). Further, we estimated the CDF based on reported forces in humans and compared the results to our model predictions. In addition, we calculated the TDF based on our CDF predictions in combination with reported resisting forces due to soft tissue presence in human cadavers. Finally, we compared the progressions to in vivo TDF measurements for validation. RESULTS Due to relaxation, a peak and resting CDF is observable for each distraction step. Our biomechanical results show a non-linear degressive increase of the resting and peak CDF at the beginning and a steady non-linear increase thereafter. The calculated resting and peak CDF in the tibial metaphysis ranged from 0.00075 to 0.0089 N and 0.22-2.6 N at the beginning as well as 20-25 N and 70-75 N at the end of distraction. The comparison to in vivo data showed the plausibility of our predictions and resulted in a 10-33% and 10-23% share of resting CDF in the total resting force for bone transport and elongation, respectively. Further, the percentage of peak CDF in total peak force was found to be 29-58% and 27-55% for bone transport and elongation, respectively. Moreover, our TDF predictions were valid based on the comparison to in vivo forces and resulted in a degressive increase from 6 to 125 N for the peak TDF and from 5 to 76 N for the resting TDF. CONCLUSION Our approach enables the estimation of forces arising due to the distraction of callus tissue in humans and results in plausible force progressions as well as absolute force values for the callus distraction force during DO. In combination with measurements of resisting forces due to the presence of soft tissue, the total distraction force in DO may also be evaluated. We thus propose the application of this method to approximate the behavior of mechanical callus properties during DO in humans as an alternative to in vivo measurements.
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Affiliation(s)
- A T Bachmeier
- 3D-Surgery, Department of General, Trauma and Reconstructive Surgery, University Hospital LMU Munich, Munich, Germany; Biomechanics and Implant Technology Research Laboratory, University Medicine Rostock, Rostock, Germany.
| | - E Euler
- Department of General, Trauma and Reconstructive Surgery, University Hospital LMU Munich, Munich, Germany
| | - R Bader
- Biomechanics and Implant Technology Research Laboratory, University Medicine Rostock, Rostock, Germany
| | - W Böcker
- Department of General, Trauma and Reconstructive Surgery, University Hospital LMU Munich, Munich, Germany
| | - P H Thaller
- 3D-Surgery, Department of General, Trauma and Reconstructive Surgery, University Hospital LMU Munich, Munich, Germany
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Barcik J, Ernst M, Balligand M, Dlaska CE, Drenchev L, Zeiter S, Epari DR, Windolf M. Short-Term Bone Healing Response to Mechanical Stimulation-A Case Series Conducted on Sheep. Biomedicines 2021; 9:988. [PMID: 34440192 PMCID: PMC8392136 DOI: 10.3390/biomedicines9080988] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 07/29/2021] [Accepted: 08/05/2021] [Indexed: 11/29/2022] Open
Abstract
It is well known that mechanical stimulation promotes indirect fracture healing by triggering callus formation. We investigated the short-term response of healing tissue to mechanical stimulation to compare the changes in tissue stiffness during stimulation and resting phases in a preclinical case-series. Four sheep underwent a tibial osteotomy and were instrumented with a custom-made active fixator which applied a mechanical stimulation protocol of 1000 cycles/day, equally distributed over 12 h, followed by 12 h of rest. During each cycle, a surrogate metric for tissue stiffness was measured, enabling a continuous real-time monitoring of the healing progression. A daily stiffness increase during stimulation and an increase during resting were evaluated for each animal. One animal had to be excluded from the evaluation due to technical reasons. For all included animals, the stiffness began to increase within the second week post-op. A characteristic pattern was observed during daily measurements: the stiffness dropped considerably within the first stimulation cycles followed by a steady rise throughout the rest of the stimulation phase. However, for all included animals, the average daily stiffness increase within the first three weeks post operation was larger during resting than during stimulation (Sheep I: 16.9% vs. -5.7%; Sheep II: 14.7% vs. -1.8%; Sheep III: 8.9% vs. 1.6%). A continuous measurement of tissue stiffness together with a controlled fracture stimulation enabled the investigation of the short-term effects of specific stimulatory parameters, such as resting periods. Resting was identified as a potentially determining factor for bone healing progression. Optimizing the ratio between stimulation and resting may contribute to more robust fracture healing in the future.
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Affiliation(s)
- Jan Barcik
- AO Research Institute Davos, Clavadelerstrasse 8, 7270 Davos, Switzerland; (M.E.); (S.Z.); (M.W.)
- Bulgarian Academy of Sciences, Institute of Metal Science ‘Acad. A. Balevski’, Shipchenski Prohod 67, 1574 Sofia, Bulgaria;
| | - Manuela Ernst
- AO Research Institute Davos, Clavadelerstrasse 8, 7270 Davos, Switzerland; (M.E.); (S.Z.); (M.W.)
| | - Marc Balligand
- Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Liège, Quartier Vallée 2, Avenue de Cureghem 7A–7D, 4000 Liège, Belgium;
| | | | - Ludmil Drenchev
- Bulgarian Academy of Sciences, Institute of Metal Science ‘Acad. A. Balevski’, Shipchenski Prohod 67, 1574 Sofia, Bulgaria;
| | - Stephan Zeiter
- AO Research Institute Davos, Clavadelerstrasse 8, 7270 Davos, Switzerland; (M.E.); (S.Z.); (M.W.)
| | - Devakara R. Epari
- Institute of Health and Biomedical Innovation, Queensland University of Technology, George Street 2, Brisbane, QLD 4000, Australia;
| | - Markus Windolf
- AO Research Institute Davos, Clavadelerstrasse 8, 7270 Davos, Switzerland; (M.E.); (S.Z.); (M.W.)
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Barcik J, Epari DR. Can Optimizing the Mechanical Environment Deliver a Clinically Significant Reduction in Fracture Healing Time? Biomedicines 2021; 9:691. [PMID: 34207370 PMCID: PMC8234230 DOI: 10.3390/biomedicines9060691] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 06/14/2021] [Accepted: 06/16/2021] [Indexed: 11/17/2022] Open
Abstract
The impact of the local mechanical environment in the fracture gap on the bone healing process has been extensively investigated. Whilst it is widely accepted that mechanical stimulation is integral to callus formation and secondary bone healing, treatment strategies that aim to harness that potential are rare. In fact, the current clinical practice with an initially partial or non-weight-bearing approach appears to contradict the findings from animal experiments that early mechanical stimulation is critical. Therefore, we posed the question as to whether optimizing the mechanical environment over the course of healing can deliver a clinically significant reduction in fracture healing time. In reviewing the evidence from pre-clinical studies that investigate the influence of mechanics on bone healing, we formulate a hypothesis for the stimulation protocol which has the potential to shorten healing time. The protocol involves confining stimulation predominantly to the proliferative phase of healing and including adequate rest periods between applications of stimulation.
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Affiliation(s)
- Jan Barcik
- AO Research Institute Davos, Clavadelerstrasse 8, 7270 Davos, Switzerland
- Bulgarian Academy of Sciences, Institute of Metal Science “Acad. A. Balevski”, Shipchenski prohod 67, 1574 Sofia, Bulgaria
| | - Devakara R. Epari
- Institute of Health and Biomedical Innovation, Queensland University of Technology, George Street 2, Brisbane, QLD 4000, Australia;
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Barcik J, Ernst M, Dlaska CE, Drenchev L, Zeiter S, Epari DR, Windolf M. Programable Active Fixator System for Systematic In Vivo Investigation of Bone Healing Processes. SENSORS (BASEL, SWITZERLAND) 2020; 21:E17. [PMID: 33375087 PMCID: PMC7792812 DOI: 10.3390/s21010017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 12/15/2020] [Accepted: 12/19/2020] [Indexed: 12/19/2022]
Abstract
This manuscript introduces a programable active bone fixator system that enables systematic investigation of bone healing processes in a sheep animal model. In contrast to previous systems, this solution combines the ability to precisely control the mechanical conditions acting within a fracture with continuous monitoring of the healing progression and autonomous operation of the system throughout the experiment. The active fixator system was implemented on a double osteotomy model that shields the experimental fracture from the influence of the animal's functional loading. A force sensor was integrated into the fixator to continuously measure stiffness of the repair tissue as an indicator for healing progression. A dedicated control unit was developed that allows programing of different loading protocols which are later executed autonomously by the active fixator. To verify the feasibility of the system, it was implanted in two sheep with different loading protocols, mimicking immediate and delayed weight-bearing, respectively. The implanted devices operated according to the programmed protocols and delivered seamless data over the whole course of the experiment. The in vivo trial confirmed the feasibility of the system. Hence, it can be applied in further preclinical studies to better understand the influence of mechanical conditions on fracture healing.
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Affiliation(s)
- Jan Barcik
- AO Research Institute Davos, Clavadelerstrasse 8, 7270 Davos, Switzerland; (M.E.); (S.Z.); (M.W.)
- Bulgarian Academy of Sciences, Institute of Metal Science ‘Acad. A. Balevski’, Shipchenski prohod 67, 1574 Sofia, Bulgaria;
| | - Manuela Ernst
- AO Research Institute Davos, Clavadelerstrasse 8, 7270 Davos, Switzerland; (M.E.); (S.Z.); (M.W.)
| | - Constantin E. Dlaska
- Orthopaedic Research Institute of Queensland, 7 Turner Street, Townsville, QLD 4812, Australia;
| | - Ludmil Drenchev
- Bulgarian Academy of Sciences, Institute of Metal Science ‘Acad. A. Balevski’, Shipchenski prohod 67, 1574 Sofia, Bulgaria;
| | - Stephan Zeiter
- AO Research Institute Davos, Clavadelerstrasse 8, 7270 Davos, Switzerland; (M.E.); (S.Z.); (M.W.)
| | - Devakara R. Epari
- Institute of Health and Biomedical Innovation, Queensland University of Technology, George Street 2, Brisbane City, QLD 4000, Australia;
| | - Markus Windolf
- AO Research Institute Davos, Clavadelerstrasse 8, 7270 Davos, Switzerland; (M.E.); (S.Z.); (M.W.)
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Uniaxial Static Strain Promotes Osteoblast Proliferation and Bone Matrix Formation in Distraction Osteogenesis In Vitro. BIOMED RESEARCH INTERNATIONAL 2020; 2020:3906426. [PMID: 32855965 PMCID: PMC7443025 DOI: 10.1155/2020/3906426] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 06/24/2020] [Accepted: 07/27/2020] [Indexed: 11/18/2022]
Abstract
Objective We aimed at investigating the effects of uniaxial static strain on osteoblasts in distraction osteogenesis (DO). Methods To simulate the mechanical stimulation of osteoblasts during DO, 10% uniaxial static strain was applied to osteoblasts using a homemade multiunit cell stretching and compressing device. Before and after applying strain stimulation, the morphological changes of osteoblasts were observed by inverted phase-contrast microscopy, Coomassie blue staining, and immunofluorescence. Alkaline phosphatase (ALP) activity, mRNA levels (proliferating cell nuclear antigen [PCNA], ALP, Runx2, osteocalcin [OCN], collagen type I, hypoxia-inducible factor- [HIF-] 1α, and vascular endothelial growth factor [VEGF]), and protein levels (Runx2, OCN, collagen type I, HIF-1α, and VEGF) were evaluated by using ALP kit, real-time quantitative reverse transcription-polymerase chain reaction, western blot, and enzyme-linked immunosorbent assay. Results After the mechanical stimulation, the cytoskeleton microfilaments were rearranged, and the cell growth direction of the osteoblasts became ordered, with their direction being at an angle of about 45° from the direction of strain. The proliferation of osteoblasts and the expression levels of mRNA and protein of ALP, Runx2, OCN, collagen type I, HIF-1α, and VEGF were significantly higher than in the nonstretch control groups. Conclusion Our homemade device can exert uniaxial static strain and promote the proliferation of osteoblasts and bone matrix formation. It can be used to simulate the mechanical stimulation of osteoblasts during DO.
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Blázquez-Carmona P, Mora-Macías J, Sanz-Herrera JA, Morgaz J, Navarrete-Calvo R, Domínguez J, Reina-Romo E. Mechanical Influence of Surrounding Soft Tissue on Bone Regeneration Processes: A Bone Lengthening Study. Ann Biomed Eng 2020; 49:642-652. [PMID: 32808118 DOI: 10.1007/s10439-020-02592-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 08/11/2020] [Indexed: 10/23/2022]
Abstract
Bone lengthening is a bone regeneration technique with multiple clinical applications. One of the most common complications of this treatment is the lack of adaptation of the surrounding soft tissue to their extension. A better understanding of the mechanobiology of the tissues involved in distraction osteogenesis would allow better control of the clinical cases. Bone lengthening treatments were performed in vivo in the metatarsus of Merino sheep, measuring the distraction forces by means of an instrumented fixator. The tissue relaxation after distraction was analyzed in this study. A viscoelastic model was also applied to distraction data to assess the mechanical behavior of the tissues during the distraction phase. Tissue relaxation is similar to other bone regeneration processes which do not imply surrounding soft tissue extension, e.g. bone transport. The effects of this tissue on distraction forces are limited to the first minutes of distraction and elongations above 4% of the original length with the protocol applied. Moreover, the surrounding soft tissue initially loses some of its viscoelasticity and subsequently suffers strain hardening from day 5 of distraction until the end of the distraction phase, day 15. Finally, anatomical changes were also evidenced in the elongated limb of our specimens.
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Affiliation(s)
- Pablo Blázquez-Carmona
- Escuela Técnica Superior de Ingeniería, Universidad de Sevilla, Avenida Camino de los Descubrimientos s/n, 41092, Seville, Spain.
| | - Juan Mora-Macías
- Escuela Técnica Superior de Ingeniería, Universidad de Huelva, 21007, Huelva, Spain
| | - José Antonio Sanz-Herrera
- Escuela Técnica Superior de Ingeniería, Universidad de Sevilla, Avenida Camino de los Descubrimientos s/n, 41092, Seville, Spain
| | - Juan Morgaz
- Departamento Medicina y Cirugía Animal, Campus Universitario de Rabanales, Ctra. Nacional IV-A, Km 396, 14014, Córdoba, Spain
| | - Rocío Navarrete-Calvo
- Departamento Medicina y Cirugía Animal, Campus Universitario de Rabanales, Ctra. Nacional IV-A, Km 396, 14014, Córdoba, Spain
| | - Jaime Domínguez
- Escuela Técnica Superior de Ingeniería, Universidad de Sevilla, Avenida Camino de los Descubrimientos s/n, 41092, Seville, Spain
| | - Esther Reina-Romo
- Escuela Técnica Superior de Ingeniería, Universidad de Sevilla, Avenida Camino de los Descubrimientos s/n, 41092, Seville, Spain
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Blázquez-Carmona P, Sanchez-Raya M, Mora-Macías J, Gómez-Galán JA, Domínguez J, Reina-Romo E. Real-Time Wireless Platform for In Vivo Monitoring of Bone Regeneration. SENSORS 2020; 20:s20164591. [PMID: 32824259 PMCID: PMC7472372 DOI: 10.3390/s20164591] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 08/12/2020] [Accepted: 08/14/2020] [Indexed: 01/08/2023]
Abstract
For the monitoring of bone regeneration processes, the instrumentation of the fixation is an increasingly common technique to indirectly measure the evolution of bone formation instead of ex vivo measurements or traditional in vivo techniques, such as X-ray or visual review. A versatile instrumented external fixator capable of adapting to multiple bone regeneration processes was designed, as well as a wireless acquisition system for the data collection. The design and implementation of the overall architecture of such a system is described in this work, including the hardware, firmware, and mechanical components. The measurements are conditioned and subsequently sent to a PC via wireless communication to be in vivo displayed and analyzed using a developed real-time monitoring application. Moreover, a model for the in vivo estimation of the bone callus stiffness from collected data was defined. This model was validated in vitro using elastic springs, reporting promising results with respect to previous equipment, with average errors and uncertainties below 6.7% and 14.04%. The devices were also validated in vivo performing a bone lengthening treatment on a sheep metatarsus. The resulting system allowed the in vivo mechanical characterization of the bone callus during experimentation, providing a low-cost, simple, and highly reliable solution.
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Affiliation(s)
- Pablo Blázquez-Carmona
- Escuela Técnica Superior de Ingeniería, Universidad de Sevilla, 41092 Seville, Spain; (J.D.); (E.R.-R.)
- Correspondence: ; Tel.: +34-601-174-347
| | - Manuel Sanchez-Raya
- Escuela Técnica Superior de Ingeniería, Universidad de Huelva, 21007 Huelva, Spain; (M.S.-R.); (J.M.-M.); (J.A.G.-G.)
| | - Juan Mora-Macías
- Escuela Técnica Superior de Ingeniería, Universidad de Huelva, 21007 Huelva, Spain; (M.S.-R.); (J.M.-M.); (J.A.G.-G.)
| | - Juan Antonio Gómez-Galán
- Escuela Técnica Superior de Ingeniería, Universidad de Huelva, 21007 Huelva, Spain; (M.S.-R.); (J.M.-M.); (J.A.G.-G.)
| | - Jaime Domínguez
- Escuela Técnica Superior de Ingeniería, Universidad de Sevilla, 41092 Seville, Spain; (J.D.); (E.R.-R.)
| | - Esther Reina-Romo
- Escuela Técnica Superior de Ingeniería, Universidad de Sevilla, 41092 Seville, Spain; (J.D.); (E.R.-R.)
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Claes L, Meyers N. The direction of tissue strain affects the neovascularization in the fracture-healing zone. Med Hypotheses 2020; 137:109537. [DOI: 10.1016/j.mehy.2019.109537] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 12/16/2019] [Accepted: 12/19/2019] [Indexed: 12/27/2022]
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Becker K, Schwarz F, Rauch NJ, Khalaph S, Mihatovic I, Drescher D. Can implants move in bone? A longitudinal in vivo micro-CT analysis of implants under constant forces in rat vertebrae. Clin Oral Implants Res 2019; 30:1179-1189. [PMID: 31494964 DOI: 10.1111/clr.13531] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 06/24/2019] [Accepted: 08/22/2019] [Indexed: 11/30/2022]
Abstract
OBJECTIVES Whereas stationary stability of implants has been postulated for decades, recent studies suggested a phenomenon termed implant migration. This describes a change in position of implants as a reaction to applied forces. The present study aims at employing image registration of in vivo micro-CT scans from different time points and to assess (a) if migration of continuously loaded implants is possible and (b) migration correlates with the force magnitude. MATERIAL AND METHODS Two customized machined implants were placed in the dorsal portion of caudal vertebrae in n = 61 rats and exposed to standardized forces (0.5 N, 1.0 N, and 1.5 N) applied through a flat nickel-titanium contraction spring, or no forces (control). Micro-CT scans were performed at 0, 1, 2, 4, 6, and 8 weeks after surgery. The baseline image was registered with the forthcoming scans. Implant migration was measured as the Euclidean distance between implant tips. Bone remodeling was assessed between the baseline and the forthcoming scans. RESULTS The findings confirmed a positional change of the implants at 2 and 8 weeks of healing, and a linear association between applied force and velocity of movement (anterior implant: χ2 = 12.12, df = 3, and p = .007 and posterior implant: χ2 = 20.35, df = 3, and p < .001). Bone apposition was observed around the implants and accompanied by formation of load-bearing trabeculae and a general cortical thickening close and also distant to the implants. CONCLUSION The present analysis confirmed that implants can migrate in bone. The applied forces seemed to stimulate bone thickening, which could explain why implants migrate without affecting stability.
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Affiliation(s)
- Kathrin Becker
- Department of Orthodontics, Universitätsklinikum Düsseldorf, Düsseldorf, Germany.,Department of Oral Surgery and Implantology, Carolinum, Goethe University, Frankfurt, Germany
| | - Frank Schwarz
- Department of Oral Surgery and Implantology, Carolinum, Goethe University, Frankfurt, Germany
| | - Nicole Jasmin Rauch
- Department of Orthodontics, Universitätsklinikum Düsseldorf, Düsseldorf, Germany
| | - Silava Khalaph
- Department of Orthodontics, Universitätsklinikum Düsseldorf, Düsseldorf, Germany
| | - Ilja Mihatovic
- Department of Oral Surgery, Universitätsklinikum Düsseldorf, Düsseldorf, Germany
| | - Dieter Drescher
- Department of Orthodontics, Universitätsklinikum Düsseldorf, Düsseldorf, Germany
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Hatefi S, Etemadi Sh M, Yihun Y, Mansouri R, Akhlaghi A. Continuous distraction osteogenesis device with MAAC controller for mandibular reconstruction applications. Biomed Eng Online 2019; 18:43. [PMID: 30961605 PMCID: PMC6454606 DOI: 10.1186/s12938-019-0655-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2018] [Accepted: 03/19/2019] [Indexed: 01/24/2023] Open
Abstract
Background Distraction osteogenesis (DO) is a novel technique widely used in human body reconstruction. DO has got a significant role in maxillofacial reconstruction applications (MRA); through this method, bone defects and skeletal deformities in various cranio-maxillofacial areas could be reconstructed with superior results in comparison to conventional methods. Recent studies revealed in a DO solution, using an automatic continuous distractor could significantly improve the results while decreasing the existing issues. This study is aimed at designing and developing a novel automatic continuous distraction osteogenesis (ACDO) device to be used in the MRA. Methods The design is comprised of a lead screw translation mechanism and a stepper motor, placed outside of the mouth to generate the desired continuous linear force. This externally generated and controlled distraction force (DF) is transferred into the moving bone segment via a flexible miniature transition system. The system is also equipped with an extra-oral ACDO controller, to generate an accurate, reliable, and stable continuous DF. Results Simulation and experimental results have justified the controller outputs and the desired accuracy of the device. Experiments have been conducted on a sheep jaw bone and results have showed that the developed device could offer a continuous DF of 38 N with distraction accuracy of 7.6 nm on the bone segment, while reducing the distraction time span. Conclusion Continuous DF with high resolution positioning control, along with the smaller size of the distractor placed in the oral cavity will help in improving the result of the reconstruction operation and leading to a successful DO procedure in a shorter time period. The developed ACDO device has less than 1% positioning error while generating sufficient DF. These features make this device a suitable distractor for an enhanced DO treatment in MRA.
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Affiliation(s)
- Shahrokh Hatefi
- Department of Mechatronics Engineering, Nelson Mandela University, Port Elizabeth, South Africa
| | - Milad Etemadi Sh
- Department of Oral and Maxillofacial Surgery, Isfahan University of Medical Sciences, Isfahan, Iran.
| | - Yimesker Yihun
- Department of Mechanical Engineering, Wichita State University, Wichita, USA
| | - Roozbeh Mansouri
- Center for Advanced Engineering Research, Najaf Abad Branch, Islamic Azad University, Isfahan, Iran
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Claes L, Meyers N, Schülke J, Reitmaier S, Klose S, Ignatius A. The mode of interfragmentary movement affects bone formation and revascularization after callus distraction. PLoS One 2018; 13:e0202702. [PMID: 30138362 PMCID: PMC6107229 DOI: 10.1371/journal.pone.0202702] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 08/06/2018] [Indexed: 12/22/2022] Open
Abstract
Callus distraction is sometimes associated with a delay in the maturation process and serious complications. It is believed that these complications are often caused by instability of the bone segment fixation. Typical fixation devices, such as ring-fixators, show significant deformations in all directions under external loading and muscle forces. This leads to axial compression and tension as well as shear movements in the healing area. Herein we investigated the hypothesis that the direction of interfragmentary movement after callus distraction affects the bone formation and revascularization during the maturation process. Two custom fixator systems were designed to apply a protocol of lateral callus distraction and subsequent cyclic stimulation of the regenerate tissue. One fixator system was used to apply either compressive or tensile stimulation while the other was used to apply shearing stimulation. The fixators were applied to the tibial surface of the right hind leg of sheep specimens. During lateral callus distraction, a titanium plate was elevated by 0.275 mm perpendicular to the long axis of the bone twice daily, resulting in a 5.5 mm gap at the end of the ten-day distraction phase. Following a seven-day consolidation phase, the regenerate in the gap between tibial cortex and titanium plate was stimulated once daily by cyclic movement for 120 cycles. The stimulation was applied for 18 days with amplitudes of 0.6 mm in compression (Group C) or tension (Group T), or a 1.0 mm shear amplitude (Group S). Seven weeks postoperatively the specimens were analyzed for quantity of bone formation, the presence of cartilage and fibrous tissue, and blood vessel density. There was a significantly higher blood vessel density (4.6 ± 1.6%) in Group C than in Group T (1.2 ± 0.4%) or Group S (1.0 ± 0.5%) (p < 0.01). The amount of bone was significantly higher in Group C (25.6% ± 13.0%) than in Group T (13.5 ± 4.9%) (p < 0.05). Group S showed a similar amount of bone (14.0 ± 10.7%) to Group T. The results show that bone formation and revascularization are dependent on the direction of interfragmentary movement and that the cyclic compression best stimulates the healing process.
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Affiliation(s)
- Lutz Claes
- Institute of Orthopedic Research and Biomechanics, Center of Musculoskeletal Research, University of Ulm, Ulm, Germany
| | - Nicholaus Meyers
- Institute of Orthopedic Research and Biomechanics, Center of Musculoskeletal Research, University of Ulm, Ulm, Germany
| | - Julian Schülke
- Institute of Orthopedic Research and Biomechanics, Center of Musculoskeletal Research, University of Ulm, Ulm, Germany
| | - Sandra Reitmaier
- Institute of Orthopedic Research and Biomechanics, Center of Musculoskeletal Research, University of Ulm, Ulm, Germany
| | - Svenja Klose
- Institute of Orthopedic Research and Biomechanics, Center of Musculoskeletal Research, University of Ulm, Ulm, Germany
| | - Anita Ignatius
- Institute of Orthopedic Research and Biomechanics, Center of Musculoskeletal Research, University of Ulm, Ulm, Germany
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12
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Meyers N, Schülke J, Ignatius A, Claes L. Evolution of callus tissue behavior during stable distraction osteogenesis. J Mech Behav Biomed Mater 2018; 85:12-19. [PMID: 29803766 DOI: 10.1016/j.jmbbm.2018.05.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 04/11/2018] [Accepted: 05/09/2018] [Indexed: 10/16/2022]
Abstract
Multiple studies have sought to characterize the mechanical behavior of callus tissue in vivo during distraction osteogenesis. The aims of such studies are to understand the mechanobiology of distraction and elucidate the complex viscoelasticity and evolution of the tissue. The former objective has direct clinical relevance to surgical technique and process control while the latter is necessary for the calibration and validation of the predictive healing models. Such models seek to reduce the researcher's dependence on animal studies and prospectively allow improved surgical planning. To date, no study has been capable of controlling the mechanical conditions sufficiently enough to decouple the distraction process from the secondary mechanical stimulation associated with the finite stiffness of the fixation constructs employed. It is the goal of this work to understand the mechanobiology of pure distraction as well as characterize viscoelastic tissue behavior under precisely defined mechanical conditions. This is achieved using a novel lateral distraction model. The structural integrity of the bone is maintained, allowing the collection of force relaxation data due to a stepwise distraction process without the superimposed influence of secondary mechanical stimulation. The average instantaneous modulus increases from approximately 2 kPa to approximately 1100 kPa while the equilibrium modulus increases from approximately 0 kPa to 200 kPa over the distraction period.
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Affiliation(s)
- Nicholaus Meyers
- Institute of Orthopedic Research and Biomechanics, Center of Musculoskeletal Research Ulm, University Hospital Ulm, Ulm, Baden-Württemberg, Germany.
| | - Julian Schülke
- Institute of Orthopedic Research and Biomechanics, Center of Musculoskeletal Research Ulm, University Hospital Ulm, Ulm, Baden-Württemberg, Germany
| | - Anita Ignatius
- Institute of Orthopedic Research and Biomechanics, Center of Musculoskeletal Research Ulm, University Hospital Ulm, Ulm, Baden-Württemberg, Germany
| | - Lutz Claes
- Institute of Orthopedic Research and Biomechanics, Center of Musculoskeletal Research Ulm, University Hospital Ulm, Ulm, Baden-Württemberg, Germany
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13
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Schuelke J, Meyers N, Reitmaier S, Klose S, Ignatius A, Claes L. Intramembranous bone formation after callus distraction is augmented by increasing axial compressive strain. PLoS One 2018; 13:e0195466. [PMID: 29624608 PMCID: PMC5889182 DOI: 10.1371/journal.pone.0195466] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 03/22/2018] [Indexed: 01/24/2023] Open
Abstract
The mechanical environment is a primary factor in the success of distraction osteogenesis. It is known that the interfragmentary movement during the distraction and maturation phase effects the callus formation. In addition to cyclic compression, other movements like shear and bending influence the bone formation process as shown in previous callus distraction studies. Reports of cartilage presence and endochondral ossification in the regenerative zone have been associated with a lack of fixation stability and delayed healing. So far the effects of the direction of interfragmentary movements could not be studied separately. By means of a unique lateral callus distraction model, we investigated the effects of small (0.1 mm) and moderate (0.6 mm), purely axial compression on ossification during callus maturation in sheep. A distraction device incorporating a mobile titanium plate was mounted on the tibia. Following lateral callus distraction, electromechanically controlled movements allowed purely axial cyclic compression of the tissue regenerate. Seven weeks post-operatively, the tissue regenerates were investigated using μCT, histology and immunohistochemistry. The larger amplitude significantly increased bone formation (Fractional bone volume: 19.4% vs. 5.2%, p = 0.03; trabecular thickness: 0.1 mm vs. 0.06 mm, p = 0.006; mean spicule height: 2.6 mm vs. 1.1 mm, p = 0.02) however, no endochondral ossification occurred. The elimination of shear movement, unimpaired neovascularization as well as the tensile strain stimuli during the distraction phase suppressing chondrogenic differentiation may all contribute to the absence of cartilage. In clinical application of distraction osteogenesis, moderate axial interfragmentary movement augments intramembranous ossification provided shear strain is minimized.
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Affiliation(s)
- Julian Schuelke
- Institute of Orthopedic Research and Biomechanics, Center of Musculoskeletal Research Ulm, University Hospital Ulm, Ulm, Baden-Württemberg, Germany
| | - Nicholaus Meyers
- Institute of Orthopedic Research and Biomechanics, Center of Musculoskeletal Research Ulm, University Hospital Ulm, Ulm, Baden-Württemberg, Germany
| | - Sandra Reitmaier
- Institute of Orthopedic Research and Biomechanics, Center of Musculoskeletal Research Ulm, University Hospital Ulm, Ulm, Baden-Württemberg, Germany
| | - Svenja Klose
- Institute of Orthopedic Research and Biomechanics, Center of Musculoskeletal Research Ulm, University Hospital Ulm, Ulm, Baden-Württemberg, Germany
| | - Anita Ignatius
- Institute of Orthopedic Research and Biomechanics, Center of Musculoskeletal Research Ulm, University Hospital Ulm, Ulm, Baden-Württemberg, Germany
| | - Lutz Claes
- Institute of Orthopedic Research and Biomechanics, Center of Musculoskeletal Research Ulm, University Hospital Ulm, Ulm, Baden-Württemberg, Germany
- * E-mail:
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