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Liu X, Astudillo Potes MD, Serdiuk V, Dashtdar B, Schreiber AC, Rezaei A, Lee Miller A, Hamouda AM, Shafi M, Elder BD, Lu L. Injectable bioactive poly(propylene fumarate) and polycaprolactone based click chemistry bone cement for spinal fusion in rabbits. J Biomed Mater Res A 2024. [PMID: 38644548 DOI: 10.1002/jbm.a.37725] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 04/02/2024] [Accepted: 04/04/2024] [Indexed: 04/23/2024]
Abstract
Degenerative spinal pathology is a widespread medical issue, and spine fusion surgeries are frequently performed. In this study, we fabricated an injectable bioactive click chemistry polymer cement for use in spinal fusion and bone regrowth. Taking advantages of the bioorthogonal click reaction, this cement can be crosslinked by itself eliminating the addition of a toxic initiator or catalyst, nor any external energy sources like UV light or heat. Furthermore, nano-hydroxyapatite (nHA) and microspheres carrying recombinant human bone morphogenetic protein-2 (rhBMP-2) and recombinant human vascular endothelial growth factor (rhVEGF) were used to make the cement bioactive for vascular induction and osteointegration. After implantation into a rabbit posterolateral spinal fusion (PLF) model, the cement showed excellent induction of new bone formation and bridging bone, achieving results comparable to autograft control. This is largely due to the osteogenic properties of nano-hydroxyapatite (nHA) and the released rhBMP-2 and rhVEGF growth factors. Since the availability of autograft sources is limited in clinical settings, this injectable bioactive click chemistry cement may be a promising alternative for spine fusion applications in addressing various spinal conditions.
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Affiliation(s)
- Xifeng Liu
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota, USA
| | - Maria D Astudillo Potes
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota, USA
| | - Vitalii Serdiuk
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota, USA
| | - Babak Dashtdar
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota, USA
| | - Areonna C Schreiber
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota, USA
| | - Asghar Rezaei
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota, USA
| | - A Lee Miller
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Mahnoor Shafi
- Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota, USA
| | - Benjamin D Elder
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota, USA
- Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota, USA
| | - Lichun Lu
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota, USA
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Liu X, Astudillo Potes MD, Serdiuk V, Dashtdar B, Schreiber AC, Rezaei A, Miller AL, Hamouda AM, Shafi M, Elder BD, Lu L. Bioactive Moldable Click Chemistry Polymer Cement with Nano-Hydroxyapatite and Growth Factor-Enhanced Posterolateral Spinal Fusion in a Rabbit Model. ACS Appl Bio Mater 2024; 7:2450-2459. [PMID: 38500414 DOI: 10.1021/acsabm.4c00073] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/20/2024]
Abstract
Spinal injuries or diseases necessitate effective fusion solutions, and common clinical approaches involve autografts, allografts, and various bone matrix products, each with limitations. To address these challenges, we developed an innovative moldable click chemistry polymer cement that can be shaped by hand and self-cross-linked in situ for spinal fusion. This self-cross-linking cement, enabled by the bioorthogonal click reaction, excludes the need for toxic initiators or external energy sources. The bioactivity of the cement was promoted by incorporating nanohydroxyapatite and microspheres loaded with recombinant human bone morphogenetic protein-2 and vascular endothelial growth factor, fostering vascular induction and osteointegration. The release kinetics of growth factors, mechanical properties of the cement, and the ability of the scaffold to support in vitro cell proliferation and differentiation were evaluated. In a rabbit posterolateral spinal fusion model, the moldable cement exhibited remarkable induction of bone regeneration and effective bridging of spine vertebral bodies. This bioactive moldable click polymer cement therefore presents a promising biomaterial for spinal fusion augmentation, offering advantages in safety, ease of application, and enhanced bone regrowth.
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Affiliation(s)
- Xifeng Liu
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota 55905, United States
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota 55905, United States
| | - Maria D Astudillo Potes
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota 55905, United States
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota 55905, United States
| | - Vitalii Serdiuk
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota 55905, United States
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota 55905, United States
| | - Babak Dashtdar
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota 55905, United States
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota 55905, United States
| | - Areonna C Schreiber
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota 55905, United States
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota 55905, United States
| | - Asghar Rezaei
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota 55905, United States
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota 55905, United States
| | - A Lee Miller
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota 55905, United States
| | - Abdelrahman M Hamouda
- Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota 55905, United States
| | - Mahnoor Shafi
- Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota 55905, United States
| | - Benjamin D Elder
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota 55905, United States
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota 55905, United States
- Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota 55905, United States
| | - Lichun Lu
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota 55905, United States
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota 55905, United States
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Hamouda AM, Pennington Z, Shafi M, Astudillo Potis MD, Hallak H, Graff-Radford J, Jones DT, Botha H, Cutsforth-Gregory JK, Cogswell PM, Elder BD. Ventriculoperitoneal shunt placement safety in idiopathic Normal Pressure Hydrocephalus: Anticoagulated versus non-anticoagulated patients. World Neurosurg 2024:S1878-8750(24)00581-3. [PMID: 38604534 DOI: 10.1016/j.wneu.2024.04.018] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 04/02/2024] [Accepted: 04/03/2024] [Indexed: 04/13/2024]
Abstract
BACKGROUND Many patients with idiopathic normal pressure hydrocephalus (iNPH) have medical comorbidities requiring anticoagulation that could negatively impact outcomes. This study evaluated the safety of ventriculoperitoneal shunt (VPS) placement in iNPH patients on systemic anticoagulation versus those not on anticoagulation. METHODS Patients > 60 years of age with iNPH who underwent shunting between 2018 and 2022 were retrospectively reviewed. Baseline demographics, comorbidities (quantified by modified Frailty Index (mFI) and Charlson Comorbidity Index (CCI)), anticoagulant/antiplatelet agent use (other than aspirin), operative details, and complications were collected. Outcomes of interest were the occurrence of postoperative hemorrhage and overdrainage. RESULTS A total of 234 patients were included in the study (mean age 75.22 ± 6.04 years; 66.7% male); 36 were on anticoagulation/antiplatelet therapy (excluding aspirin). This included 6 on Warfarin, 19 on direct Xa inhibitors, 10 on Clopidogrel, and one on both Clopidogrel and Warfarin. Notably, 70% of patients (164/234) used aspirin alone or combined with anticoagulation or clopidogrel. Baseline mFI was similar between groups, but those on anticoagulant/antiplatelet therapy had a higher mean CCI (2.67±1.87 vs. 1.75±1.84; p=0.001). Patients on anticoagulants were more likely to experience tract hemorrhage (11.1 vs. 2.5%; p=0.03), with no significant difference in the rates of intraventricular hemorrhage or overdrainage related subdural fluid collection. CONCLUSIONS Anticoagulant and antiplatelet agents are common in the iNPH population, and patients on these agents experienced higher rates of tract hemorrhage following VPS placement; however, overall hemorrhagic complication rates were similar.
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Affiliation(s)
| | - Zach Pennington
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, 55905, USA
| | - Mahnoor Shafi
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, 55905, USA
| | | | - Hannah Hallak
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, 55905, USA
| | | | - David T Jones
- Department of Neurology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Hugo Botha
- Department of Neurology, Mayo Clinic, Rochester, MN, 55905, USA
| | | | | | - Benjamin D Elder
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, 55905, USA.
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Swart A, Hamouda AM, Pennington Z, Mikula AL, Martini M, Lakomkin N, Shafi M, Nassr AN, Sebastian AS, Fogelson JL, Freedman BA, Elder BD. Reduced Bone Density Based on Hounsfield Units After Long-Segment Spinal Fusion with Harrington Rods. World Neurosurg 2024:S1878-8750(24)00260-2. [PMID: 38373686 DOI: 10.1016/j.wneu.2024.02.063] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 02/10/2024] [Accepted: 02/12/2024] [Indexed: 02/21/2024]
Abstract
BACKGROUND Long-segment instrumentation, such as Harrington rods, offloads vertebrae within the construct, which may result in significant stress shielding of the fused segments. The present study aimed to determine the effects of spinal fusion on bone density by measuring Hounsfield units (HUs) throughout the spine in patients with a history of Harrington rod fusion. METHODS Patients with a history of Harrington rod fusion treated at a single academic institution were identified. Mean HUs were calculated at 5 spinal segments for each patient: cranial adjacent mobile segment, cranial fused segment, midconstruct fused segment, caudal fused segment, and caudal adjacent mobile segment. Mean HUs for each level were compared using a paired-sample t test, with statistical significance defined by P < 0.05. Hierarchic multiple regression, including age, gender, body mass index, and time since original fusion, was used to determine predictors of midfused segment HUs. RESULTS One hundred patients were included (mean age, 55 ± 12 years; 62% female). Mean HUs for the midconstruct fused segment (110; 95% confidence interval [CI], 100-121) were significantly lower than both the cranial and caudal fused segments (150 and 118, respectively; both P < 0.05), as well as both the cranial and caudal adjacent mobile segments (210 and 130, respectively; both P < 0.001). Multivariable regression showed midconstruct HUs were predicted only by patient age (-2.6 HU/year; 95% CI, -3.4 to -1.9; P < 0.001) and time since original surgery (-1.4 HU/year; 95% CI, -2.6 to -0.2; P = 0.02). CONCLUSIONS HUs were significantly decreased in the middle of previous long-segment fusion constructs, suggesting that multilevel fusion constructs lead to vertebral bone density loss within the construct, potentially from stress shielding.
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Affiliation(s)
- Alexander Swart
- Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Zach Pennington
- Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota, USA
| | - Anthony L Mikula
- Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota, USA
| | - Michael Martini
- Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota, USA
| | - Nikita Lakomkin
- Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota, USA
| | - Mahnoor Shafi
- Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota, USA
| | - Ahmad N Nassr
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota, USA
| | - Arjun S Sebastian
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota, USA
| | - Jeremy L Fogelson
- Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota, USA
| | - Brett A Freedman
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota, USA
| | - Benjamin D Elder
- Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota, USA.
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Hamouda AM, Pennington Z, Astudillo Potes M, Mikula AL, Lakomkin N, Martini ML, Abode-Iyamah KO, Freedman BA, McClendon J, Nassr AN, Sebastian AS, Fogelson JL, Elder BD. The Predictors of Incidental Durotomy in Patients Undergoing Pedicle Subtraction Osteotomy for the Correction of Adult Spinal Deformity. J Clin Med 2024; 13:340. [PMID: 38256474 PMCID: PMC10816915 DOI: 10.3390/jcm13020340] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 01/05/2024] [Accepted: 01/05/2024] [Indexed: 01/24/2024] Open
Abstract
Background: Pedicle subtraction osteotomy (PSO) is a powerful tool for sagittal plane correction in patients with rigid adult spinal deformity (ASD); however, it is associated with high intraoperative blood loss and the increased risk of durotomy. The objective of the present study was to identify intraoperative techniques and baseline patient factors capable of predicting intraoperative durotomy. Methods: A tri-institutional database was retrospectively queried for all patients who underwent PSO for ASD. Data on baseline comorbidities, surgical history, surgeon characteristics and intraoperative maneuvers were gathered. PSO aggressiveness was defined as conventional (Schwab 3 PSO) or an extended PSO (Schwab type 4). The primary outcome of the study was the occurrence of durotomy intraoperatively. Univariable analyses were performed with Mann-Whitney U tests, Chi-squared analyses, and Fisher's exact tests. Statistical significance was defined by p < 0.05. Results: One hundred and sixteen patients were identified (mean age 61.9 ± 12.6 yr; 44.8% male), of whom 51 (44.0%) experienced intraoperative durotomy. There were no significant differences in baseline comorbidities between those who did and did not experience durotomy, with the exception that baseline weight and body mass index were higher in patients who did not suffer durotomy. Prior surgery (OR 2.73; 95% CI [1.13, 6.58]; p = 0.03) and, more specifically, prior decompression at the PSO level (OR 4.23; 95% CI [1.92, 9.34]; p < 0.001) was predictive of durotomy. A comparison of surgeon training showed no statistically significant difference in durotomy rate between fellowship and non-fellowship trained surgeons, or between orthopedic surgeons and neurosurgeons. The PSO level, PSO aggressiveness, the presence of stenosis at the PSO level, nor the surgical instrument used predicted the odds of durotomy occurrence. Those experiencing durotomy had similar hospitalization durations, rates of reoperation and rates of nonroutine discharge. Conclusions: In this large multisite series, a history of prior decompression at the PSO level was associated with a four-fold increase in intraoperative durotomy risk. Notably the use of extended (versus) standard PSO, surgical technique, nor baseline patient characteristics predicted durotomy. Durotomies occurred in 44% of patients and may prolong operative times. Additional prospective investigations are merited.
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Affiliation(s)
- Abdelrahman M. Hamouda
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN 55905, USA; (A.M.H.); (M.A.P.)
| | - Zach Pennington
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN 55905, USA; (A.M.H.); (M.A.P.)
| | - Maria Astudillo Potes
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN 55905, USA; (A.M.H.); (M.A.P.)
| | - Anthony L. Mikula
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN 55905, USA; (A.M.H.); (M.A.P.)
| | - Nikita Lakomkin
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN 55905, USA; (A.M.H.); (M.A.P.)
| | - Michael L. Martini
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN 55905, USA; (A.M.H.); (M.A.P.)
| | | | - Brett A. Freedman
- Department of Orthopaedic Surgery, Mayo Clinic, Rochester, MN 55905, USA
| | - Jamal McClendon
- Department of Neurologic Surgery, Mayo Clinic, Phoenix, AZ 85054, USA;
| | - Ahmad N. Nassr
- Department of Orthopaedic Surgery, Mayo Clinic, Rochester, MN 55905, USA
| | - Arjun S. Sebastian
- Department of Orthopaedic Surgery, Mayo Clinic, Rochester, MN 55905, USA
| | - Jeremy L. Fogelson
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN 55905, USA; (A.M.H.); (M.A.P.)
| | - Benjamin D. Elder
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN 55905, USA; (A.M.H.); (M.A.P.)
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Martini ML, Mikula AL, Lakomkin N, Pennington Z, Everson MC, Hamouda AM, Bydon M, Freedman B, Sebastian AS, Nassr A, Anderson PA, Baffour F, Kennel KA, Fogelson J, Elder B. Opportunistic CT-Based Hounsfield Units Strongly Correlate with Biomechanical CT Measurements in the Thoracolumbar Spine. Spine (Phila Pa 1976) 2023:00007632-990000000-00456. [PMID: 37678376 DOI: 10.1097/brs.0000000000004822] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 08/28/2023] [Indexed: 09/09/2023]
Abstract
STUDY DESIGN Retrospective cohort study. OBJECTIVE Hounsfield units (HUs) are known to correlate with clinical outcomes, no study has evaluated how they correlate with BCT and DXA measurements. SUMMARY OF BACKGROUND Low bone mineral density (BMD) represents a major risk factor for fracture and poor outcomes following spine surgery. Dual-energy x-ray absorptiometry (DXA) can provide regional BMD measurements but has limitations. Opportunistic HUs provide targeted BMD estimates; however, they are not formally accepted for diagnosing osteoporosis in current guidelines. More recently, biomechanical computed tomography (BCT) analysis has emerged as a new modality endorsed by the International Society for Clinical Densitometry (ISCD) for assessing bone strength. METHODS Consecutive cases from 2017-2022 at a single institution were reviewed for patients who underwent BCT in the thoracolumbar spine. BCT-measured vertebral strength, trabecular BMD, and the corresponding American College of Radiology (ACR) Classification were recorded. DXA studies within three months of the BCT were reviewed. Pearson Correlation Coefficients were calculated, and receiver-operating characteristic curves were constructed to assess the predictive capacity of HUs. Threshold analysis was performed to identify optimal HU values for identifying osteoporosis and low BMD. RESULTS Correlation analysis of 114 cases revealed a strong relationship between HUs and BCT vertebral strength (r=0.69; P<0.0001; R2=0.47) and trabecular BMD (r=0.76; P<0.0001; R2=0.58). However, DXA poorly correlated with opportunistic HUs and BCT measurements. HUs accurately predicted osteoporosis and low BMD (Osteoporosis: C=0.95, 95% CI 0.89-1.00; Low BMD: C=0.87, 95% CI 0.79-0.96). Threshold analysis revealed that 106 and 122 HUs represent optimal thresholds for detecting osteoporosis and low BMD. CONCLUSION Opportunistic HUs strongly correlated with BCT-based measures, while neither correlated strongly with DXA-based BMD measures in the thoracolumbar spine. HUs are easy to perform at no additional cost and provide accurate BMD estimates at non-instrumented vertebral levels across all ACR-designated BMD categories.
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Affiliation(s)
- Michael L Martini
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN 55905, USA
| | - Anthony L Mikula
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN 55905, USA
| | - Nikita Lakomkin
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN 55905, USA
| | - Zach Pennington
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN 55905, USA
| | - Megan C Everson
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN 55905, USA
| | | | - Mohamad Bydon
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN 55905, USA
| | - Brett Freedman
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN 55905, USA
| | - Arjun S Sebastian
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN 55905, USA
| | - Ahmad Nassr
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN 55905, USA
| | - Paul A Anderson
- Department of Orthopedic Surgery & Rehabilitation, University of Wisconsin UWMF, Centennial Bldg, Madison, WI 53705-2281, USA
| | - Francis Baffour
- Department of Radiology, Mayo Clinic, Rochester, MN 55905, USA
| | - Kurt A Kennel
- Division of Endocrinology, Mayo Clinic, Rochester, MN 55905, USA
| | - Jeremy Fogelson
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN 55905, USA
| | - Benjamin Elder
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN 55905, USA
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How CK, Megat Ahmad MM, Radin Umar RS, Hamouda AM, Harwant S. Crash simulation of lower limb with motorcycle basket. Med J Malaysia 2001; 56:77-81. [PMID: 11503301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Lower limb injuries are the main cause of temporary and permanent disability among motorcyclists in Malaysia. They cause non-fatal but serious injuries requiring hospitalisation. Detailed studies on factors influencing lower limb injuries are justified in an attempt to reduce the occurrence of these injuries. This study presents a computer simulation of the crash behaviour of the basket of a small-engined motorcycle with the lower limb using finite element (FE) methods. The results suggest that the extensive deformation of the motorcycle basket may reduce the risk of injury to the lower limb. The behaviour of the basket during collision is analogous to the crumple zone of automobiles.
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Affiliation(s)
- C K How
- Road Safety Research Centre, Universiti Putra Malaysia, 43400 Serdang, Selangor
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el-Hadary MS, Rashed AF, Kamar AA, Hamouda AM, Ibrahim MM, Hafez AM. Aging effect on the mechanical properties of dental amalgam. Alex Dent J 1977; 2:9-34. [PMID: 296669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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