Finite element analysis on lower cervical spine by anterior cervical corpectomy and fusion sugery / 医用生物力学

Objective To establish the three-dimensional finite element model of human lower cervical spine C3-7 motion segments after anterior cervical corpectomy and fusion (ACCF) surgery with titanium mesh and bone graft,and to analyze the stability of cervical spine and stress distribution of internal fixation devices after ACCF surgery.Methods The finite element model of cervical spine C3-7 segments after ACCF of C5 segment with titanium mesh,bone graft,plate and screw fixation was established,and C3-7 segment intact model of cervical vertebra was also constructed.The torque moment of 0.5,1.0,1.5,2.0 N · m was applied to the ACCF surgery model.The ROM,maximum stress in facet joint and stress distributions on internal fixation devices under flexion,extension,lateral bending and axial rotation movement were analyzed.Results ROM of reconstructed C5 segment increased with the torque moment increasing after ACCF surgery.In the case of 1.0 N · m tomue moment and 50 N preload,the ROM of reconstructed C5,C3-4,C6-7 and C3-7 segment was reduced by 81％,62％,58％ and 80％ compared with the intact model.The maximum stress in facet joint of reconstructed C5 segment reduced and the stress in adjacent segments significantly increased.The stress of titanium mesh was mainly distributed on the compression side of movement,and high stress was located in the roots of screws.Conclusions ACCF surgery can promote the stability of cewical spine,decrease the stress in facet joint of operation segment,and has better treatment effect on easing compression from spinal cord caused by cervical spondylotic myelopathy.The research results will provide some theoretical basis for clinical application of ACCF surgery.

Finite element analysis on lower cervical spine by anterior cervical corpectomy and fusion sugery / 医用生物力学

Objective To establish the three-dimensional finite element model of human lower cervical spine C3-7 motion segments after anterior cervical corpectomy and fusion (ACCF) surgery with titanium mesh and bone graft, and to analyze the stability of cervical spine and stress distribution of internal fixation devices after ACCF surgery. Methods The finite element model of cervical spine C3-7 segments after ACCF of C5 segment with titanium mesh, bone graft, plate and screw fixation was established，and C3-7 segment intact model of cervical vertebra was also constructed. The torque moment of 0.5, 1.0, 1.5, 2.0 N﹒m was applied to the ACCF surgery model. The ROM, maximum stress in facet joint and stress distributions on internal fixation devices under flexion, extension, lateral bending and torsion movement were analyzed. Results ROM of reconstructed C5 segment increased with the torque moment increasing after ACCF surgery. In the case of 1.0 N﹒m torque moment and 50 N preload, the ROM of reconstructed C5, C3-4, C6-7 and C3-7 segment was reduced by 81%, 62%, 58% and 80% compared with the intact model. The maximum stress in facet joint of reconstructed C5 segment reduced and the stress in adjacent segments significantly increased. The stress of titanium mesh was mainly distributed on the compression side of movement, and high stress was located in the roots of screws. Conclusions ACCF surgery can promote the stability of cervical spine, decrease the stress in facet joint of operation segment, and has better treatment effect on easing compression from spinal cord caused by cervical spondylotic myelopathy. The research results will provide some theoretical basis for clinical application of ACCF.

Finite element analysis on lower cervical spine by anterior cervical corpectomy and fusion sugery / 医用生物力学

Objective To establish the three-dimensional finite element model of human lower cervical spine C3-7 motion segments after anterior cervical corpectomy and fusion (ACCF) surgery with titanium mesh and bone graft,and to analyze the stability of cervical spine and stress distribution of internal fixation devices after ACCF surgery.Methods The finite element model of cervical spine C3-7 segments after ACCF of C5 segment with titanium mesh,bone graft,plate and screw fixation was established,and C3-7 segment intact model of cervical vertebra was also constructed.The torque moment of 0.5,1.0,1.5,2.0 N · m was applied to the ACCF surgery model.The ROM,maximum stress in facet joint and stress distributions on internal fixation devices under flexion,extension,lateral bending and axial rotation movement were analyzed.Results ROM of reconstructed C5 segment increased with the torque moment increasing after ACCF surgery.In the case of 1.0 N · m tomue moment and 50 N preload,the ROM of reconstructed C5,C3-4,C6-7 and C3-7 segment was reduced by 81％,62％,58％ and 80％ compared with the intact model.The maximum stress in facet joint of reconstructed C5 segment reduced and the stress in adjacent segments significantly increased.The stress of titanium mesh was mainly distributed on the compression side of movement,and high stress was located in the roots of screws.Conclusions ACCF surgery can promote the stability of cewical spine,decrease the stress in facet joint of operation segment,and has better treatment effect on easing compression from spinal cord caused by cervical spondylotic myelopathy.The research results will provide some theoretical basis for clinical application of ACCF surgery.

Finite element analysis on lower cervical spine by anterior cervical corpectomy and fusion sugery / 医用生物力学

Objective To establish the three-dimensional finite element model of human lower cervical spine C3-7 motion segments after anterior cervical corpectomy and fusion (ACCF) surgery with titanium mesh and bone graft,and to analyze the stability of cervical spine and stress distribution of internal fixation devices after ACCF surgery.Methods The finite element model of cervical spine C3-7 segments after ACCF of C5 segment with titanium mesh,bone graft,plate and screw fixation was established,and C3-7 segment intact model of cervical vertebra was also constructed.The torque moment of 0.5,1.0,1.5,2.0 N · m was applied to the ACCF surgery model.The ROM,maximum stress in facet joint and stress distributions on internal fixation devices under flexion,extension,lateral bending and axial rotation movement were analyzed.Results ROM of reconstructed C5 segment increased with the torque moment increasing after ACCF surgery.In the case of 1.0 N · m tomue moment and 50 N preload,the ROM of reconstructed C5,C3-4,C6-7 and C3-7 segment was reduced by 81％,62％,58％ and 80％ compared with the intact model.The maximum stress in facet joint of reconstructed C5 segment reduced and the stress in adjacent segments significantly increased.The stress of titanium mesh was mainly distributed on the compression side of movement,and high stress was located in the roots of screws.Conclusions ACCF surgery can promote the stability of cewical spine,decrease the stress in facet joint of operation segment,and has better treatment effect on easing compression from spinal cord caused by cervical spondylotic myelopathy.The research results will provide some theoretical basis for clinical application of ACCF surgery.

Extensive Metallosis Caused by Plate and Screw Construct for Distal Fibular Fracture - A Case Report -

Metallosis has been reported in the setting of weight-bearing joint arthroplasties, like the hip and knee joints. However, the prevalence of metallosis in non-articular portions is very uncommon. We report a rare case of a patient who had metallosis secondary by fibular nonunion after fixation with plate and screw. In addition, we discuss the clinical and the operative findings, as well as the outcome of this uncommon complication.

Plate and Screw Removal after Orthognathic Surgery, under Intravenous Sedation with Dexmedetomidine and Pethidine

0.05). Amnesia during local injection was observed in eight patients (34.8%). Compared with the preoperative anxiety score, the intraoperative anxiety score was decreased.CONCLUSION: In this study, we found cardiovascular and respiratory stability in intravenous sedation using dexmedetomidine with pethidine, in plate and screw removal, after orthognathic surgery. Furthemore, intravenous sedation using dexmedetomidine with pethidine shows adequate analgesic and sedative effects.

Fixation with Bioabsorbable Polylactide Plate and Screws for the Treatment of the Ankle Fractures / 대한족부족관절학회지

PURPOSE: The purpose of this article is to assess the efficacy of a bioabsorbable polylactide (PLA) plate and screw for treating injuries of ankle fractures. MATERIALS AND METHODS:24 patients who underwent an open reduction and internal fixation operation for ankle fractures from July 2005 to March 2007 were enrolled into the study. There were 15 men and 9 women. The average age of the patients was 44 years and the average follow-up period was 16 years and two months (16.2 months). All cases were divided into low grade fracture patient (11) who belongs in type A and B of Danis-Weber classification and high grade fracture patient (13) who belongs in type C1, C2 of Danis-Weber classification, and each groups were analyzed by clinical (Meyer score) and radiological finding at the time of their last follow-up evaluation. RESULTS:The clinical results according to Meyer scoring system, showed that all patient with low grade fracture had good to excellent result, but only 54% of patient with high grade fracture had good to excellent result. According to Cedell's radiologic finding, there were 91% cases above fair in low grade fracture. But there were 62% of patient above fair result in high grade fracture, the reduction losses were seen in 38% of patient with high grade fracture. CONCLUSION: Bioabsorbable PLA plate and screw is good internal fixation device which doesn't have additional operation for removal of implant because of slow absorption within the human body. It showed sufficient strength for acquisition and maintenance of reduction in low grade fracture, but need attention to use because of many cases of reduction loss in high grade fracture. So, it seems to be safe and effective when used in heeling of low grade fracture under considering about type of fracture sufficiently.

A Clinical Study of Biodegradable Plates and Screws in Oral and Maxillofacial Surgery

Metallic bone plates and screws have been commonly used in oral and maxillofacial surgery for internal fixation. However, there are several disadvantages such as atrophy of cortical bone inherent to excessive rigid fixation systems, growth disturbance in growing individual, allergy reaction, interference with radiographic imaging, palpability, thermal sensitibity and the need for subsequent removal. To overcome these disadvantages and avoid additional surgery of removal of plates and screws, there have been many studies of biodegradable plates and screws. But, It also has complication such as foreign body reactions. We have undertaken a clinical and retrospective study on 140 patients in Dept. of Oral and Maxillofacial Surgery, Inha University Hospital from February 2006 to March 2009. The purpose of this study is to report the clinical cases and review of the literatures with biodegradable plates and screws. And we concluded following results. 1. 6 cases(3.4%) of the 177 operation sites(140 patients) experienced complications. 1 case(0.6%) was a failure of initial fixation, 1 case(0.6%) was a postoperative infection, 4 cases(2.3%) were inflammations or foreign body reaction. 2. Postoperative infections, inflammations and foreign body reactions were completely recovered with incision and drainage, supporative care with antibiotic coverage and removal of biodegradable plates. 3. Biodegradable plates and screws provide acceptable rigidity and stability clinically. But, long-term observation is required for the tissue reactions around the biodegradable plates and screws because of long resorption periods of the biodegradable materials.

The Clinical use of Absorbable Plate and Screw in Mandibular Fracture

Rigid fixation techniques with absorbable plates and screws are recently utilized for the repair of craniofacial skeletal injuries or congenital anomalies. But no domestic literature are presented in treatments of mandible fracture. We present our early experience of absorbable plates and screws in fixation of mandible fracture. Eleven patients underwent fixation procedures for mandible fracture with absorbable plates and screws. Intraoperative stability was satisfactory in all cases. Significant problems, such as nonunion, malunion, delayed union and malocclusion from the use of absorbable plating system were not found, but there were two cases of localized inflammation. We also experienced advantages of absorbable plating system which are biodegradation, radiolucency and enough stability for reduction state. The use of absorbable plating system would eliminate potential effects on skeletal growth- restriction in child, problems associated with long- term palpability and visibility in X-ray, and cold sensitivity caused by traditional metal plating system. There are also several disadvantages of absorbable plates and screws. This plating system takes increased operative time and needs delicate technique relative to the traditional metal plating system. Nevertheless we concluded that absorbable plates and screws are good fixatives for mandibular fracture.

Anterior Ceervical Interbody Fusion: Comparison Study between Simple Fusion, Locked and Non-locked Plating Systems

The use of metallic plate and screws in the anterior cervical fusion has become generally acceptable and popular. Mainly, there are two different plating systems available. However, there has been few attempts to compare their clinical results with and without a plating system or between two different systems in a single series of clinical study. The authors reviewed 117 patients who underwent anterior cervical fusion during the period of January 1992 to September 1996. Simple fusion without a plating system was applied in 55 cases(group 1), a bicortical non-locked plate screw system in 25(group 2), and a monocortical locked plate screw system in 37(group 3). The average follow-up period was 13. 2 months. In group 1, twenty-two patients(40%) with fracture-dislocation or corpectomy required a rigid brace such as halo brace and Minerva cast for 3 months postope ratively and seven patients(13%) experienced graft complications, mainly graft extrusion. In group 2 and 3, the patients required only soft b races for 4 to 8 weeks and no patients experienced serious graft complications like ones in group 1 but, instead two patients with screw breakages, two back-outs and one non-union were observed. In comparison of the clinical complications such as hoarsness, there were no significant differences between the groups. In conclusion, the plating system in anterior cervical fusion appears to be safe despite the facts that mo re technical demands are required during surgery. It also provides better postoperative stability in the spine and permits earlier ambulation without a rigid brace. A monocortical locked plate screw system appears to have less hardware failures and better su rgical results than a bicortical non-locked plate screw system.

Anterior Cervical interbody Fusion with Cervical Spine Locking Plate / 영남의대학술지

OBJECTIVES: Anterior approach to achieve arthrodesis of the cervical spine has become a widely accepted and often-used approach since its earliest reports by Bailey and Badgley, Smith and Robinson and Cloward. However, anterior interbody fusion in the presence of the presence of the posterior instability may be complicated by the bone graft dislodgement, kyphotic defomity or nonunion. As an attemp to prevent this undesirable complication, additional methods such as skeletal traction, halo appratus or even posterior fusion has been utilized. Therefore, The cervical spine locking plate(CSLP) with the anterior intervertebral body bone grafting provide immediate cervical stabilization and widely successful in achieving fusion. MATERIAL AND METHODS: This study analysed 14 patients who underwent a single anterior procedure and application of CSLP for the treatment of the cervical spinal disorder. Eleven patients were disc herniations and three patients were traumatic lesion. The average ago of the patient was 47 years and the mean follow up periods was 20 months ranging from 13 to 27 months. RESULTS: Ambulation was started 2nd day after the operation with the aid of the Philadelpia orthoses. Bone union was observed 13 cases on average 12 weeks after operation. The one case was nonunion with plate breakage without clinical symptom. CONCLUSION: Anterior fusion with CSLP are thought to be a safe and valuable method for treating cervical spine disorder.

An Animal Experiment on the Biocompatibility of AISI 316 LVM Stainless Steel Plates and Screws Manufactured at KAIST / 대한정형외과학회잡지

In order to assess the biocompatibility of domestic dynamic compression plates and screws manufactured at KAIST (Korea Advanced Institute of Science and Technclogy), hematological, serological, histological, and metallurgical studies were carried out on sixty rabbits through thirty-two weeks. The rabbits were divided into two groups, group I: thirty rabbits for KAIST plates and screws, group II: thirty rabbits for Osteo plates and screws. The plate and screws were fixed on the fixed tibial shaft. All the resulg of hematological, serological, histological, and metallurgical study revealed that there were no meaningful differences between the two groups. This, in fact, enco.urages us to use domestic KAIST plates and screws clinically and to develop more complicated designs including total joint replacement system.

Clinical Failures of Internal Fixation / 대한정형외과학회잡지

Since the first attemt of internal fixation not much more than a century ago, implants have come to play an important role in orthopaedic surgery. Yet little has been reported about complications which may result from implant surgery. During the period of May 1980 to April 1984, 32 cases of fixation failures were treated in the Department of Orthopaedic Surgery, Hallym College, Kang Nam Sacred Heart Hospital and results were obtained as follows: 1. The most common area involved femoral shaft, but the highest rate was distal femur. 2. The most common period of failure was between 2 to 4 months postoperatively. 3. The leading cause of failure was remaining defects at fracture site. 4. The authors recommend accurate reduction of fracture and bone graft, if necessary, adequate immobilization postoperatively and co-coperation of patient to avoid failure of implant.