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Lutz R, Schulz KL, Weber M, Olmos M, Möst T, Bürstner J, Kesting MR. An ex vivo model for education and training of unilateral cleft lip surgery. BMC Med Educ 2023; 23:765. [PMID: 37828467 PMCID: PMC10571449 DOI: 10.1186/s12909-023-04667-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 09/11/2023] [Indexed: 10/14/2023]
Abstract
BACKGROUND Unilateral cleft lip surgery is a complex procedure, and the outcome depends highly on the surgeon's experience. Digital simulations and low-fidelity models seem inadequate for effective surgical education and training. There are only few realistic models for haptic simulation of cleft surgery, which are all based on synthetic materials that are costly and complex to produce. Hence, they are not fully available to train and educate surgical trainees. This study aims to develop an inexpensive, widely available, high-fidelity, ex vivo model of a unilateral cleft lip using a porcine snout disc. METHODS A foil template was manufactured combining anatomical landmarks of the porcine snout disc and the anatomical situation of a child with a unilateral cleft. This template was used to create an ex vivo model of a unilateral cleft lip from the snout disc. Millard II technique was applied on the model to proof its suitability. The individual steps of the surgical cleft closure were photo-documented and three-dimensional scans of the model were analysed digitally. Sixteen surgical trainees were instructed to create a unilateral cleft model and perform a unilateral lip plasty. Their self-assessment was evaluated by means of a questionnaire. RESULTS The porcine snout disc proved highly suitable to serve as a simulation model for unilateral cleft lip surgery. Millard II technique was successfully performed as we were able to perform all steps of unilateral cleft surgery, including muscle suturing. The developed foil-template is reusable on any porcine snout disc. The creation of the ex vivo model is simple and inexpensive. Self-assessment of the participants showed a strong increase in comprehension and an eagerness to use the model for surgical training. CONCLUSIONS A porcine snout disc ex vivo model of unilateral cleft lips was developed successfully. It shows many advantages, including a haptic close to human tissue, multiple layers, low cost, and wide and rapid availability. It is therefore very suitable for teaching and training beginners in cleft surgery and subsequently improving surgical skills and knowledge. Further research is needed to finally assess the ex vivo model's value in different stages of the curriculum of surgical residency.
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Affiliation(s)
- Rainer Lutz
- Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Glückstrasse 11, 91054, Erlangen, Germany.
| | - Katja Leonie Schulz
- Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Glückstrasse 11, 91054, Erlangen, Germany
| | - Manuel Weber
- Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Glückstrasse 11, 91054, Erlangen, Germany
| | - Manuel Olmos
- Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Glückstrasse 11, 91054, Erlangen, Germany
| | - Tobias Möst
- Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Glückstrasse 11, 91054, Erlangen, Germany
| | - Jan Bürstner
- Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Glückstrasse 11, 91054, Erlangen, Germany
| | - Marco Rainer Kesting
- Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Glückstrasse 11, 91054, Erlangen, Germany
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Lutz R, Kesting MR, Weber M, Olmos M, Tasyürek D, Möst T, Bürstner J, Schulz KL. An ex vivo model for education and training of bilateral cleft lip surgery. BMC Med Educ 2023; 23:582. [PMID: 37596574 PMCID: PMC10436624 DOI: 10.1186/s12909-023-04575-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 08/07/2023] [Indexed: 08/20/2023]
Abstract
BACKGROUND Bilateral cleft lip surgery is very challenging and requires a high level of skill, knowledge and experience. Existing high-fidelity simulation models that can be used by novice cleft surgeons to gain experience and expand their knowledge are rare and expensive. In this study, we developed a bilateral cleft lip model using porcine snout discs, which are available anywhere and inexpensive. METHODS Anatomic reference points of a patient with a bilateral cleft lip were superimposed with landmarks of the porcine snout disc on a foil template. The template was used to construct an ex vivo bilateral cleft lip model. Surgery was performed on the model according to Millard and the surgical steps were photodocumented analogous to two clinical cases of bilateral cleft lip surgery. The suitability of the model was further tested by twelve participants and evaluated using self-assessment questionnaires. RESULTS The bilateral cleft lip ex vivo model made of a porcine snout disc proved to be a suitable model with very low cost and ease of fabrication, as the template is reusable on any snout disc. The Millard procedure was successfully performed and the surgical steps of the lip plasty were simulated close to the clinical situation. Regarding the nasal reconstruction, the model lacks three-dimensionality. As a training model, it enhanced the participants comprehension of cleft surgery as well as their surgical skills. All participants rated the model as valuable for teaching and training. CONCLUSIONS The porcine snout discs can be used as a useful ex vivo model for bilateral cleft lip surgery with limitations in the construction of the nose, which cannot be realistically performed with the model due to anatomical differences with humans. Benefits include a realistic tissue feel, the simulation of a multi-layered lip construction, a wide and rapid availability and low cost. This allows the model to be used by novice surgeons also in low-income countries. It is therefore useful as a training model for gaining experience, but also as a model for refining, testing and evaluating surgical techniques for bilateral lip plasty.
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Affiliation(s)
- Rainer Lutz
- Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Glückstrasse 11, 91054, Erlangen, Germany.
| | - Marco Rainer Kesting
- Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Glückstrasse 11, 91054, Erlangen, Germany
| | - Manuel Weber
- Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Glückstrasse 11, 91054, Erlangen, Germany
| | - Manuel Olmos
- Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Glückstrasse 11, 91054, Erlangen, Germany
| | - Deniz Tasyürek
- Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Glückstrasse 11, 91054, Erlangen, Germany
| | - Tobias Möst
- Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Glückstrasse 11, 91054, Erlangen, Germany
| | - Jan Bürstner
- Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Glückstrasse 11, 91054, Erlangen, Germany
| | - Katja Leonie Schulz
- Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Glückstrasse 11, 91054, Erlangen, Germany
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Rödig T, Dullin C, Kück F, Krebs M, Hettwer-Steeger I, Haupt F. Influence of moisture content of frozen and embalmed human cadavers for identification of dentinal microcracks using micro-computed tomography. J Mech Behav Biomed Mater 2022; 133:105310. [PMID: 35696968 DOI: 10.1016/j.jmbbm.2022.105310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Revised: 05/31/2022] [Accepted: 06/02/2022] [Indexed: 10/18/2022]
Abstract
The aim of this study was to investigate the influence of moisture content in frozen and embalmed human cadavers on the detection of dentinal microcracks using micro-computed tomography (micro-CT). The group of embalmed specimens included three mandibular and two maxillary segments each containing one tooth. The group of frozen cadavers consisted of two frozen mandibular bone-blocks with two teeth and one mandibular segment containing one tooth. The final number of teeth for each preservation method was n = 5. All specimens were scanned with eight different moisture conditions: 48 h wet, 2 h dry, 48 h wet, 24 h dry, 48 h wet, 1 wk dry, 48 h wet, 1 wk dry. Micro-CT images were screened for the presence of dentinal microcracks. Statistical analysis was performed by nonparametric analysis of variance (α = 5%). Only few microcracks were observed in wet and in 2 h dried bone-blocks with no significant differences (p = 0.63 and p = 0.23, respectively). There was a significant and steady increase of microcracks within the groups of dried specimens as follows: 2 h dry < 24 h dry < first wk dry < second wk dry (all p < 0.008). Preservation method had no significant influence on the visibility of microcracks (p = 0.98). Identification of dentinal microcracks on micro-CT images is influenced by moisture content of cadaveric bone-blocks irrespective of the preservation method.
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Wang S, Yu J, Helili M, Zhang C, Huang J, Wang X, Chen L, Ma X. Biomechanical assessment of two types and two different locations of subtalar arthroereisis implants for flexible flatfoot: A cadaveric study. Clin Biomech (Bristol, Avon) 2021; 89:105475. [PMID: 34525448 DOI: 10.1016/j.clinbiomech.2021.105475] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 07/30/2021] [Accepted: 08/27/2021] [Indexed: 02/07/2023]
Abstract
BACKGROUND Subtalar arthroereisis refers to the implantation of a sinus tarsi implant for the treatment of flexible flatfoot. The purpose of this study was to compare the ability to correct the flatfoot deformity and contact pressure of the posterior subtalar joint between two types of self-locking wedge implants and between two different positions for the same device in a cadaveric flatfoot model. METHODS The flatfoot model was created in ten cadaver feet through ligament sectioning and cyclic loading. Three kinds of arthroereisis procedures were evaluated: Talar-Fit (type I self-locking wedge implant) anchored in the sinus portion of the tarsal sinus (T-sinus group), Talar-Fit in the canalis portion (T-canalis group), and HyProCure (type II) in the canalis portion (H group). Corrective ability in the sagittal and transverse planes were measured with clinometers. Contact pressure was measured with pressure-sensitive films. FINDINGS T-canalis group provided more sagittal (mean difference for size 10 mm: 1.9°, P = 0.014; mean difference for size 11 mm: 3.1°, P = 0.037) and transverse (mean difference for size 8 mm: 1.8°, P = 0.049; mean difference for size 11 mm: 2.2°, P = 0.049) corrections than T-sinus group. The flattening process shifted the peak pressure of the posterior subtalar joint to the posteromedial side (P < 0.05) and arthroereisis helped the distribution of contact pressure restore uniformity (all P > 0.05). INTERPRETATION A self-locking wedge implant inserted in the canalis portion of the tarsal sinus achieved better correction than an implant inserted in the sinus portion.
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Affiliation(s)
- Sen Wang
- Department of Orthopedics, Huashan Hospital, Fudan University, 12 Middle Wulumuqi Road, Shanghai 200040, China
| | - Jian Yu
- Department of Orthopedics, Huashan Hospital, Fudan University, 12 Middle Wulumuqi Road, Shanghai 200040, China
| | - Maimaitirexiati Helili
- Department of Orthopedics, Huashan Hospital, Fudan University, 12 Middle Wulumuqi Road, Shanghai 200040, China
| | - Chao Zhang
- Department of Orthopedics, Huashan Hospital, Fudan University, 12 Middle Wulumuqi Road, Shanghai 200040, China
| | - Jiazhang Huang
- Department of Orthopedics, Huashan Hospital, Fudan University, 12 Middle Wulumuqi Road, Shanghai 200040, China
| | - Xu Wang
- Department of Orthopedics, Huashan Hospital, Fudan University, 12 Middle Wulumuqi Road, Shanghai 200040, China
| | - Li Chen
- Department of Orthopedics, Huashan Hospital, Fudan University, 12 Middle Wulumuqi Road, Shanghai 200040, China; Department of Orthopedics, Huashan Hospital North, Fudan University, 108 Luxiang Road, Shanghai 200040, China.
| | - Xin Ma
- Department of Orthopedics, Huashan Hospital, Fudan University, 12 Middle Wulumuqi Road, Shanghai 200040, China.
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van Emden MW, Geurts JJG, Schober P, Schwarte LA. Suitability and realism of the novel Fix for Life cadaver model for videolaryngoscopy and fibreoptic tracheoscopy in airway management training. BMC Anesthesiol 2020; 20:203. [PMID: 32799813 PMCID: PMC7429731 DOI: 10.1186/s12871-020-01121-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 08/06/2020] [Indexed: 11/13/2022] Open
Abstract
Background Videolaryngoscopy is increasingly advocated as the standard intubation technique, while fibreoptic intubation is broadly regarded as the ‘gold standard’ for difficult airways. Traditionally, the training of these techniques is on patients, though manikins, simulators and cadavers are also used, with their respective limitations. In this study, we investigated whether the novel ‘Fix for Life’ (F4L) cadaver model is a suitable and realistic model for the teaching of these two intubation techniques to novices in airway management. Methods Forty consultant anaesthetists and senior trainees were instructed to perform tracheal intubation with videolaryngoscopy and fibreoptic tracheoscopy in four F4L cadaver models. The primary outcome measure was the verbal rating scores (scale 1–10, higher scores indicate a better rating) for suitability and for realism of the F4L cadavers as training model for these techniques. Secondary outcomes included success rates of the procedures and the time to successful completion of the procedures. Results The mean verbal rating scores for suitability and realism for videolaryngoscopy was 8.3 (95% CI, 7.9–8.6) and 7.2 (95% CI, 6.7–7.6), respectively. For fibreoptic tracheoscopy, suitability was 8.2 (95% CI, 7.9–8.5) and realism 7.5 (95% CI, 7.1–7.8). In videolaryngoscopy, 100% of the procedures were successful. The mean (SD) time until successful tracheal intubation was 34.8 (30.9) s. For fibreoptic tracheoscopy, the success rate was 96.3%, with a mean time of 89.4 (80.1) s. Conclusions We conclude that the F4L cadaver model is a suitable and realistic model to train and teach tracheal intubation with videolaryngoscopy and fibreoptic tracheoscopy to novices in airway management training.
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Affiliation(s)
- Michael W van Emden
- Department of Anatomy and Neurosciences, Amsterdam UMC, Vrije Universiteit, PO Box 7057, 1007 MB, De Boelelaan 1117, 1081, HV, Amsterdam, The Netherlands.
| | - Jeroen J G Geurts
- Department of Anatomy and Neurosciences, Amsterdam UMC, Vrije Universiteit, PO Box 7057, 1007 MB, De Boelelaan 1117, 1081, HV, Amsterdam, The Netherlands
| | - Patrick Schober
- Department of Anaesthesiology, Amsterdam UMC, Vrije Universiteit, De Boelelaan 1117, 1081, HV, Amsterdam, The Netherlands
| | - Lothar A Schwarte
- Department of Anaesthesiology, Amsterdam UMC, Vrije Universiteit, De Boelelaan 1117, 1081, HV, Amsterdam, The Netherlands
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Whittingslow DC, Jeong HK, Ganti VG, Kirkpatrick NJ, Kogler GF, Inan OT. Acoustic Emissions as a Non-invasive Biomarker of the Structural Health of the Knee. Ann Biomed Eng 2019; 48:225-235. [PMID: 31350620 DOI: 10.1007/s10439-019-02333-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 07/20/2019] [Indexed: 11/26/2022]
Abstract
The longitudinal assessment of joint health is a long-standing issue in the management of musculoskeletal injuries. The acoustic emissions (AEs) produced by joint articulation could serve as a biomarker for joint health assessment, but their use has been limited by a lack of mechanistic understanding of their creation. In this paper, we investigate that mechanism using an injury model in human lower-limb cadavers, and relate AEs to joint kinematics. Using our custom joint sound recording system, we recorded the AEs from nine cadaver legs in four stages: at baseline, after a sham surgery, after a meniscus tear, and post-meniscectomy. We compare the resulting AEs using their b-values. We then compare joint anatomy/kinematics to the AEs using the X-ray reconstruction of moving morphology (XROMM) technique. After the meniscus tear the number and amplitude of the AE peaks greatly increased from baseline and sham (b-value = 1.33 ± 0.15; p < 0.05). The XROMM analysis showed a close correlation between the minimal inter-joint distances (0.251 ± 0.082 cm during extension, 0.265 ± .003 during flexion, at 145°) and a large increase in the AEs. This work provides key insight into the nature of joint AEs, and details a novel technique and analysis for recording and interpreting these biosignals.
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Affiliation(s)
- Daniel C Whittingslow
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA.
- Emory University School of Medicine, Atlanta, GA, USA.
| | - Hyeon-Ki Jeong
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Venu G Ganti
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Nathan J Kirkpatrick
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Geza F Kogler
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Omer T Inan
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, USA
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Chedgy E, Lowe G, Tang R, Krebs C, Sawka A, Vaghadia H, Gleave ME, So AI. Surgical placement of rectus sheath catheters in a cadaveric cystectomy model. Ann R Coll Surg Engl 2017; 100:120-124. [PMID: 29046095 DOI: 10.1308/rcsann.2017.0169] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Introduction Surgically inserted rectus sheath catheters (RSCs) are used increasingly for analgesia after cystectomy and other abdominal surgery. Currently, there is little information on the optimal positioning of RSCs to allow maximal spread of local anaesthetic. This study sought to assess the spread of dye injected via RSCs and to highlight the extent of its coverage in a fresh unembalmed cadaveric cystectomy model in order to confirm the nerve endings that are likely to be anaesthetised with RSCs. Methods Four cadavers underwent lower midline incision with limited bladder mobilisation. A RSC was inserted into the eight hemiabdomens. The RSCs were positioned either anterior (n=5) or posterior to the rectus muscle (n=3). Dye was injected down the RSCs to evaluate spread. The eight hemiabdomens were dissected anatomically to determine the surface area of dye spread and nerve root involvement. Results The mean surface area of dye spread with anteriorly placed RSCs was 30.6cm2 anterior and 25.9cm2 posterior to the rectus muscle. The mean surface area of dye spread with posteriorly placed RSCs was 11.3cm2 anterior and 37.3cm2 posterior to the rectus muscle. The mean number of nerve roots stained with anteriorly and posteriorly placed RSCs was 3.8 and 2.7 respectively. Subcutaneous spread of dye was seen with one anterior RSC insertion. Peritoneal spread was seen with one anteriorly positioned RSC. Conclusions This study has demonstrated efficient nerve root infiltration with anteriorly and posteriorly positioned RSCs. It appears that dye spreads between the fibres of the rectus muscle rather than out laterally to the nerve roots when spreading from its initial compartment.
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Affiliation(s)
- Ecp Chedgy
- University of British Columbia , Vancouver UK
| | - G Lowe
- Vancouver General Hospital , Canada
| | - R Tang
- Vancouver General Hospital , Canada
| | - C Krebs
- University of British Columbia , Vancouver UK
| | - A Sawka
- Vancouver General Hospital , Canada
| | | | - M E Gleave
- University of British Columbia , Vancouver UK
| | - A I So
- University of British Columbia , Vancouver UK
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De-Deus G, César de Azevedo Carvalhal J, Belladonna FG, Silva EJNL, Lopes RT, Moreira Filho RE, Souza EM, Provenzano JC, Versiani MA. Dentinal Microcrack Development after Canal Preparation: A Longitudinal in Situ Micro-computed Tomography Study Using a Cadaver Model. J Endod 2017; 43:1553-8. [PMID: 28735793 DOI: 10.1016/j.joen.2017.04.027] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2017] [Revised: 04/23/2017] [Accepted: 04/24/2017] [Indexed: 11/23/2022]
Abstract
INTRODUCTION The purpose of this study was to evaluate the development of dentinal microcracks after root canal preparation with Reciproc and ProTaper Universal systems using an in situ cadaver model by means of a micro-computed tomography (micro-CT) imaging system. METHODS At autopsy, 8 maxillary bone blocks having at least the first and second premolar teeth (n = 16) were excised, scanned at a resolution of 13.18 μm, and randomly distributed into 2 groups (n = 8) according to the preparation protocol: Reciproc and ProTaper Universal systems. Root canals were prepared up to R25 and F2 instruments in the Reciproc and ProTaper Universal groups, respectively. After the preparation procedures, the specimens were scanned again, and the registered preoperative and postoperative cross-section images of the roots (n = 19,060) were screened to identify the presence of dentinal defects. RESULTS In the Reciproc group, 9176 cross-section images were analyzed, and no crack was observed. In the ProTaper Universal group, 244 of 9884 cross-section slices (2.46%) had dentinal defects; however, all defects were already present in the corresponding preoperative images, indicating that no new microcrack was created after canal preparation. CONCLUSIONS In situ root canal preparation of maxillary premolars with Reciproc and ProTaper Universal systems did not induce the formation of dentinal microcracks in a cadaver model as observed by micro-CT.
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Smetana BS, Jernigan EW, Rummings WA Jr, Weinhold PS, Draeger RW, Patterson JMM. Submuscular Versus Subcutaneous Ulnar Nerve Transposition: A Cadaveric Model Evaluating Their Role in Primary Ulnar Nerve Repair at the Elbow. J Hand Surg Am 2017; 42:571.e1-7. [PMID: 28434831 DOI: 10.1016/j.jhsa.2017.03.026] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Revised: 03/15/2017] [Accepted: 03/20/2017] [Indexed: 02/02/2023]
Abstract
PURPOSE To investigate the length gained from subcutaneous and submuscular transposition of the ulnar nerve at the elbow. Specifically, the study aimed to define an expected nerve gap able to be overcome, and to determine if a difference between transposition techniques exists. METHODS Eleven cadaveric specimens from the scapula to fingertip were procured. In situ decompression and mobilization of the ulnar nerve at the elbow followed by simulated laceration of the nerve was performed. Nerves were marked 5 mm from the laceration site to facilitate overlap measurement and to simulate nerve end preparation to viable fascicles before primary coaptation. Nerve ends were attached to spring gauges set at 100 g of tension (strain ≤ 10%). Measurements of nerve overlap were obtained in varying degrees of wrist (0°, 30°, 60°) and elbow (0°, 15°, 30°, 45°, 60°, 90°) flexion. Measurements were performed after in situ decompression and mobilization, and then repeated after both subcutaneous and submuscular transposition. RESULTS Ulnar nerve transposition was found to increase nerve overlap at an elbow flexion of 30° or greater. No difference was seen between subcutaneous and submuscular transpositions at all wrist and elbow positions. In situ decompression and mobilization alone provided an average of 3.5 cm of length gain with the elbow extended. Transposition in conjunction with clinically feasible wrist and elbow flexion (30° and 60°, respectively) provided 5.2 cm of length gain. Controlling for mobilization, a statistically significant increase in overlap of approximately 2 cm was gained from transposition. CONCLUSIONS Although mobilization combined with wrist and elbow flexion may afford substantial gap reduction and should be used initially when approaching proximal ulnar nerve lacerations, transposition should be considered when faced with a large nerve gap greater than 3 cm at the elbow. No difference was seen between submuscular and subcutaneous transposition techniques. CLINICAL RELEVANCE This study defines the extent an ulnar nerve gap at the elbow can be overcome by in situ mobilization, joint positioning, and transposition. It additionally compares the efficacy of submuscular and subcutaneous transposition techniques in closing this gap.
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Somberg AM, Whiteside WK, Nilssen E, Murawski D, Liu W. Biomechanical evaluation of a second generation headless compression screw for ankle arthrodesis in a cadaver model. Foot Ankle Surg 2016; 22:50-4. [PMID: 26869501 DOI: 10.1016/j.fas.2015.04.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 04/14/2015] [Accepted: 04/20/2015] [Indexed: 02/04/2023]
Abstract
BACKGROUND Many types of screws, plates, and strut grafts have been utilized for ankle arthrodesis. Biomechanical testing has shown that these constructs can have variable stiffness. More recently, headless compression screws have emerged as an evolving method of achieving compression in various applications but there is limited literature regarding ankle arthrodesis. The aim of this study was to determine the biomechanical stability provided by a second generation fully threaded headless compression screw compared to a standard headed, partially threaded cancellous screw in a cadaveric ankle arthrodesis model. MATERIALS AND METHODS Twenty fresh frozen human cadaver specimens were subjected to simulated ankle arthrodesis with either three standard cancellous-bone screws (InFix 7.3mm) or with three headless compression screws (Acumed Acutrak 2 7.5mm). The specimens were subjected to cyclic loading and unloading at a rate of 1Hz, compression of 525 Newtons (N) and distraction of 20N for a total of 500 cycles using an electromechanical load frame (Instron). The amount of maximum distraction was recorded as well as the amount of motion that occurred through 1, 10, 50, 100, and 500 cycles. RESULTS No significant difference (p=0.412) was seen in the amount of distraction that occurred across the fusion site for either screw. The average maximum distraction after 500 cycles was 201.9μm for the Acutrak 2 screw and 235.4μm for the InFix screw. No difference was seen throughout each cycle over time for the Acutrak 2 screw (p-value=0.988) or the InFix screw (p-value=0.991). CONCLUSION Both the traditional InFix type screw and the second generation Acumed Acutrak headless compression screws provide adequate fixation during ankle arthrodesis under submaximal loads. CLINICAL RELEVANCE There is no demonstrable difference between traditional cannulated partially threaded screws and headless compression screws studied in this model.
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Affiliation(s)
- Andrew Max Somberg
- Andrews Research and Education Institute, 1040 Gulf Breeze Parkway, Gulf Breeze, FL 32561, USA
| | - William K Whiteside
- Andrews Research and Education Institute, 1040 Gulf Breeze Parkway, Gulf Breeze, FL 32561, USA.
| | - Erik Nilssen
- Andrews Research and Education Institute, 1040 Gulf Breeze Parkway, Gulf Breeze, FL 32561, USA
| | - Daniel Murawski
- Andrews Research and Education Institute, 1040 Gulf Breeze Parkway, Gulf Breeze, FL 32561, USA
| | - Wei Liu
- Auburn University, 301 Wire Road, Auburn, AL 36849, USA
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Luo WT, Almack R, Mawson JB, Cochrane DD. Radiographic Detectability of Retained Neuropatties in a Cadaver Model. World Neurosurg 2015; 84:405-11. [PMID: 25818890 DOI: 10.1016/j.wneu.2015.03.032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 03/20/2015] [Accepted: 03/21/2015] [Indexed: 11/20/2022]
Abstract
BACKGROUND Counts are the commonest method used to ensure that all sponges and neuropatties are removed from a surgical site before closure. When the count is not reconciled, plain radiographs of the operative site are taken to determine whether the missing patty has been left in the wound. The purpose of this study was to describe the detectability of commonly used neuropatties in the clinical setting using digital technologies. METHODS Neuropatties were implanted into the anterior and posterior cranial fossae and the thoracolumbar extradural space of a mature male cadaver. Four neuropatty sizes were used: 3 × 1 in, 2 × ½ in, ½ × ½ in, and ¼ × ¼ in. Neuropatties, with size and location chosen at random, were placed in the surgical sites and anteroposterior/posterior-anterior and lateral radiographs were taken using standard portable digital radiographic equipment. Six clinicians reviewed the digital images for the presence or absence of neuropatties. The readers were not aware of the number and size of the patties that were included in each image. RESULTS The detectability of neuropatties is dependent on the size of the neuropatty's radiopaque marker and the operative site. Neuropatties measuring 2 × ½ in and 3 × 1 in were detected reliably regardless of the operative site. ¼ × ¼ in neuropatties were poorly detected by neurosurgeons and radiologists in all three operative sites. Readers of various experience and background were similar in their ability to detect neuropatties under these conditions. CONCLUSIONS Under simulated operating room conditions and using currently available neuropatties and plain radiograph imaging technology, small ¼-in and ½-in neuropatties are poorly visible/detectable on digital images.
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Negri JH, Malavolta EA, Assunção JH, Gracitelli MEC, Pereira CAM, Bolliger Neto R, Croci AT, Ferreira Neto AA. Assessment of the function and resistance of sternoclavicular ligaments: A biomechanical study in cadavers. Orthop Traumatol Surg Res 2014; 100:727-31. [PMID: 25261174 DOI: 10.1016/j.otsr.2014.07.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Revised: 05/05/2014] [Accepted: 07/31/2014] [Indexed: 02/02/2023]
Abstract
BACKGROUND Few biomechanical studies have assessed the resistance of the ligamentous structures of the sternoclavicular joint, and none have reproduced the physiological movements of the joint. Determining the structures that are injured in sternoclavicular dislocations is important for the surgical planning of acute or chronic ligament reconstruction. METHODS Forty-eight joints from 24 human cadavers were studied, and they were divided into 4 groups of 12 joints each (retraction, protraction, depression and elevation). Biomechanical testing assessed primary and secondary failures. The mechanical resistance parameters between movements that occurred on the same plane (depression versus elevation, protraction versus retraction) were compared. RESULTS The posterior sternoclavicular ligament was the most injured structure during the protraction test, but it was not injured during retraction. The anterior sternoclavicular ligament was the most affected structure during retraction and depression. The costoclavicular ligament was the most affected structure during elevation. Joint resistance was significantly greater during protraction movements when compared to retraction (P<0.05). CONCLUSION The anterior sternoclavicular ligament was the most affected structure during retraction and depression movements. During protraction, lesions of the posterior sternoclavicular ligament were most frequent during elevation, and the costoclavicular ligament was the most frequently injured ligament. The resistance of the sternoclavicular joint was significantly greater during protraction movement when compared to retraction. LEVEL OF EVIDENCE IV, basic science, biomechanics, cadaver model.
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Affiliation(s)
- J H Negri
- Department of Orthopedics and Traumatology, School of Medicine, University of São Paulo (USP), São Paulo, Brazil
| | - E A Malavolta
- Department of Orthopedics and Traumatology, School of Medicine, University of São Paulo (USP), São Paulo, Brazil
| | - J H Assunção
- Department of Orthopedics and Traumatology, School of Medicine, University of São Paulo (USP), São Paulo, Brazil.
| | - M E C Gracitelli
- Department of Orthopedics and Traumatology, School of Medicine, University of São Paulo (USP), São Paulo, Brazil
| | - C A M Pereira
- Department of Orthopedics and Traumatology, School of Medicine, University of São Paulo (USP), São Paulo, Brazil
| | - R Bolliger Neto
- Department of Orthopedics and Traumatology, School of Medicine, University of São Paulo (USP), São Paulo, Brazil
| | - A T Croci
- Department of Orthopedics and Traumatology, School of Medicine, University of São Paulo (USP), São Paulo, Brazil
| | - A A Ferreira Neto
- Department of Orthopedics and Traumatology, School of Medicine, University of São Paulo (USP), São Paulo, Brazil
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Sangiorgio SN, Borkowski SL, Bowen RE, Scaduto AA, Frost NL, Ebramzadeh E. Quantification of Increase in Three-dimensional Spine Flexibility Following Sequential Ponte Osteotomies in a Cadaveric Model. Spine Deform 2013; 1:171-178. [PMID: 27927289 DOI: 10.1016/j.jspd.2013.01.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Revised: 01/09/2013] [Accepted: 01/13/2013] [Indexed: 11/30/2022]
Abstract
BACKGROUND Posterior-only procedures are becoming more popular for treatment of rigid adolescent idiopathic scoliosis, but little is known about the quantitative correction potential for Ponte osteotomies. The objective of this study was to quantify and compare the range of motion of intact multilevel thoracic spine segments with the same segments after each of 3 sequential Ponte osteotomies. METHODS We tested 5 human cadaveric thoracic spine segments, spanning T-T6, or T7-T12, in an 8-degree-of-freedom servo-hydraulic load frame, monitoring motion of each vertebra with an optical motion tracker. We measured range of motion while we applied cyclic, pure moment loading to produce flexion-extension, lateral bending, and axial rotation at a rate of 0.5°/second, to a maximum of ± 6 Nm. Each specimen was tested intact and after each of 3 sequential Ponte osteotomies. RESULTS Total range of motion for the segments (either T2-T5 or T8-T11) increased by as much as 1.6° in flexion, 1.5° in extension, 0.5° in lateral bending, and 2.8° in axial rotation with each osteotomy. Because of the variation in initial specimen stiffness, we normalized motions to the intact values. In flexion, average range of motion increased after each osteotomy compared with intact, by 33%, 56%, and 69%. In extension, slightly smaller increases were seen, increasing by as much as 56% after the third osteotomy. In lateral bending, Ponte osteotomies had little effect on range of motion. In axial rotation, range of motion increased by 16%, 29%, and 65% after 3 osteotomies. CONCLUSIONS Sequential Ponte osteotomies increased range of motion in flexion, extension, and axial rotation, but not in lateral bending. These results suggest that the Ponte osteotomy may be appropriate when using derotational correction maneuvers, or to improve apical lordosis at the apex of curvature during posterior spinal fusion procedures. Although these techniques are effective in gaining correction for kyphotic deformities and rigid curvatures, they add time and blood loss to the procedure.
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Affiliation(s)
- Sophia N Sangiorgio
- Orthopaedic Biomechanics and Mechanobiology Lab, Santa Monica UCLA Medical Center and Orthopaedic Hospital, 1250 Sixteenth St, Suite 2260, Santa Monica, CA 90404.
| | - Sean L Borkowski
- Orthopaedic Biomechanics and Mechanobiology Lab, Santa Monica UCLA Medical Center and Orthopaedic Hospital, 1250 Sixteenth St, Suite 2260, Santa Monica, CA 90404; UCLA Bioengineering/Biomedical Engineering IDP, University of California Los Angeles, 5121 Engineering V, Los Angeles, CA 90095
| | - Richard E Bowen
- Los Angeles Orthopaedic Hospital and UCLA Department of Orthopaedic Surgery, 1250 Sixteenth St, Santa Monica, CA 90404, USA
| | - Anthony A Scaduto
- Los Angeles Orthopaedic Hospital and UCLA Department of Orthopaedic Surgery, 1250 Sixteenth St, Santa Monica, CA 90404, USA
| | - Nathan L Frost
- Orthopaedic Biomechanics and Mechanobiology Lab, Santa Monica UCLA Medical Center and Orthopaedic Hospital, 1250 Sixteenth St, Suite 2260, Santa Monica, CA 90404; Los Angeles Orthopaedic Hospital and UCLA Department of Orthopaedic Surgery, 1250 Sixteenth St, Santa Monica, CA 90404, USA
| | - Edward Ebramzadeh
- Orthopaedic Biomechanics and Mechanobiology Lab, Santa Monica UCLA Medical Center and Orthopaedic Hospital, 1250 Sixteenth St, Suite 2260, Santa Monica, CA 90404
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