• Journal of Veterinary Clinics
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• v.22 no.1
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• pp.60-64
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• 2005

A 6year-old intact male hound cross dog, weighing 23 kg, was presented to the Teaching Animal Hospital, Chonbuk National University with the history of gunshot wound at the left elbow joint. Survey radiographs of the affected elbow revealed the presence of a metallic bullet caudal to the olecranon processes and comminuted fracture of the proximal radius and ulna. The first treatment strategy included removal of the bullet and fixation of the radius and ulna using separate bone plates, bone screw, K-wire and surgical wire, was failed. The second treatment strategy included olecranon osteotomy and rigid immobilization of the elbow joint with a bone plate applied to the caudal aspect of the humerus and ulna along with autogenous bone grafts collected from the 13th rib. The optimal angle of the joint following arthrodesis of this case appeared to be 130°. This resulted in improving the case but after 60 weeks the plate was bent and there was exudation from the wound. The third treatment strategy was the same with the second except for that the bone autografts were collected from the proximal metaphyses of the ipsilateral humerus. This resulted in a successful arthrodesis 6 weeks after the surgery. Elbow arthrodesis with bone autograft resulted in acceptable function, but abnormal gait remained in the dog due to mechanical interference with the movement of the joint.

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.4
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• pp.526-543
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• 2000

Finite element analyses were performed to study effects on stress distribution generated in jaw bone for various shapes of dental implants: plateau type, plateau with small radius of curvature, triangular thread screw type in accordance with ISO regulations and square thread screw filleted with small radius partially. It was found that square thread screw filleted with small radius was more effective on stress distribution than other dental implants used in analyses. Additional analyses were performed on the implant with square thread screw filleted with small radius for very-ing design parameters, such as the width of thread end, the height of the thread of the implant and load direction, to determine the optimum dimensions of the implant. The highest stress concentration occurred at the region in jaw Pone adjacent to the first thread of the implant. The maximum effective stress induced by a 15 degree oblique load of 100 N was twice as high as the maximum effective stress caused by an equal amount of vertical load. Stress distribution was more effective in the case when the width of thread end and the height of thread were p/2 and 0.46p, respectively, where p is the pitch of thread. At last, using tensile force calculated from the possible insert torque without breading bone thread, finite element analysis was performed on the implant to calculate pre-stress when the primary fixation of the implant was operated in jaw bone. The maximum effective stress was 136.8 MPa which was proven to be safe.

• Journal of Korean Neurosurgical Society
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• v.30 no.4
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• pp.493-500
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• 2001

Objective : Anterior cervical locking plates are the devices for achieving anterior cervical spinal fusion. This study was conducted to evaluate the locking plate system regarding its long-term advantages and disadvantages in the view of interbody fusion rate, hardware-related failures, vertebral change close to the fusion segment and postoperative complications. Method : Eight-six patients, operated from Jan., 1996 to Jun. 1998, were followed-up for more than two years. All of the cases were fused with iliac bone graft and ORION locking plate(Sofamor Danek USA, Inc., Memphis, TN) fixation. The patients were discharged or transferred to rehabilitation department 2-7 days after operation. A comprehensive evaluation of the interbody fusion state, instrument failure, vertebral change and postoperative complications were made by direct interview and cervical flexion-extension lateral plain films. Results : There were 55 male and 31 female with a mean age of 45 years(18-75 years). The mean follow-up period was 29 months(24-43 months). Various disorders that were operated were 40 cervical discs, 6 cervical stenosis including OPLL, 2 infections, and 38 traumas. Fusion level was single in 59 cases, two levels of each disc space in 15 cases, and two levels after one corpectomy in 12 cases. There was no instrument failure. Pseudoarthrosis was observed in two cases(2%) without radiological instability. The other patients(98%) showed complete cervical fusion with stable instrument. Mild settling of interbody graft with upward migration of screws was found in 12 cases(14%). Anterior bony growth at the upper segment was found in 5 cases(6%). Postoperative foreign body sensation or dysphagia was observed in 12 cases(4%), and disappeared within one month in 7 cases and within six months in 4 cases. One patient complained for more than six months and required reoperation to remove paraesophageal granulation tissue. Conclusion : The results show that Orion cervical locking plate has some disadvantages of upward migration of screws, anterior bony growth at the upper segment, or possibility of esophageal compression even though it has advantages of high interbody fusion rate or low instrument failure. Author believe that anterior cervical locking plate in the future should be thinner, and should have short end from the screw hole, and movable screw with adequate stability.

• Journal of the Korean Arthroscopy Society
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• v.7 no.2
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• pp.183-188
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• 2003

Purpose : The purpose of this study is to evaluate the results of revision surgery for failed anterior cruciate ligament (ACL) reconstruction using quadruple hamstring tendon autograft. Materials and Methods : From May 2000 to July 2002, six patients received ACL revision surgery using quadruple hamstring autograft for failed ACL reconstruction. Femoral tunnels were made 40 mm in depth and fixed with a cross pin and a bioabsorbable interference screw to fill the bone defect. In tibial tunnels, the grafts were fixed with Intrafix(Mitek, Norwood, MA). In case of tibial tunnel widening, additional screw-washer fixation was done. Follow up was at least 12 months postoperatively. Clinical assessments consisted of Lysholm knee scores, International Knee Documentation Committee(IKDC) evaluation form and manual maximal side to side difference using KT-2000 arthrometer. Results : The average Lysholm knee score improved from 77.2 preoperatively to 87.7 postoperatively. At the final IKDC evaluation, 1 case was graded as normal, 4 nearly normal, 1 abnormal. Mean side to side difference of manual maximum anterior displacement using the KT-2000 arthrometer was 1.8mm. The success rate was $83\%$. Conclusion : ACL revision surgery using quadruple hamstring autograft with double fixation is considered good procedure with successful results.

• Journal of Korean Neurosurgical Society
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• v.61 no.6
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• pp.680-688
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• 2018

Objective : To mitigate the risk of iatrogenic instability, new posterior decompression techniques able to preserve musculoskeletal structures have been introduced but never extensively investigated from a biomechanical point of view. This study was aimed to investigate the impact on spinal flexibility caused by a unilateral laminotomy for bilateral decompression, in comparison to the intact condition and a laminectomy with preservation of a bony bridge at the vertebral arch. Secondary aims were to investigate the biomechanical effects of two-level decompression and the quantification of the restoration of stability after posterior fixation. Methods : A universal spine tester was used to measure the flexibility of six L2-L5 human spine specimens in intact conditions and after decompression and fixation surgeries. An incremental damage protocol was applied : 1) unilateral laminotomy for bilateral decompression at L3-L4; 2) on three specimens, the unilateral laminotomy was extended to L4-L5; 3) laminectomy with preservation of a bony bridge at the vertebral arch (at L3-L4 in the first three specimens and at L4-L5 in the rest); and 4) pedicle screw fixation at the involved levels. Results : Unilateral laminotomy for bilateral decompression had a minor influence on the lumbar flexibility. In flexion-extension, the median range of motion increased by 8%. The bone-preserving laminectomy did not cause major changes in spinal flexibility. Two-level decompression approximately induced a twofold destabilization compared to the single-level treatment, with greater effect on the lower level. Posterior fixation reduced the flexibility to values lower than in the intact conditions in all cases. Conclusion : In vitro testing of human lumbar specimens revealed that unilateral laminotomy for bilateral decompression and bone-preserving laminectomy induced a minor destabilization at the operated level. In absence of other pathological factors (e.g., clinical instability, spondylolisthesis), both techniques appear to be safe from a biomechanical point of view.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1527-1532
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• 2008

45% of the sports accidents is the knee damage and the representative case is the damage of an Anterior Cruciate Ligament (ACL) and the Posterior Cruciate Ligament(PCL). Although the past different views of ACL reconstruction comes to an agreement, the disputes of PCL is remained yet. The most important engineering approach for these various surgery techniques is accurately to understand and to evaluate the fatigue behavior depending on the stress flow and the stress distribution under the allotted load and the cyclic load, which are caused by the graft fixing device, the proximal tibia of the PCL reconstructing structure. Therefore, this study is the basic research of these above facts. The current transtibial tunnel surgery using the cadaveric Achilles tendon grafts is chosen for the various PCL reconstruction. The relationships between the slippage, the extension ratio, and the slippage ratio by the heel bone fixing method and the soft tissue fixing method of the Achilles tendon were also defined. This research will be the essential data to help the resonable operating techniques for the next PCL reconstruction.

• Journal of Korean Foot and Ankle Society
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• v.21 no.1
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• pp.27-32
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• 2017

Purpose: Bone grafting is often necessary to maintain a reduction and prevent delayed collapse of reduced fracture in a treatment of severely displaced comminuted intra-articular calcaneal fractures. Herein, we analyzed the usefulness and necessary conditions to perform tricortical-allobone grafting in open reduction of calcaneal fracture via the Ollier approach. Materials and Methods: We performed a retrospective review of 57 intra-articular calcaneal fractures that underwent an operation via the Ollier approach between April 2009 and April 2015. They were divided into two groups: Group 1 (n=17) included those with tricortical-allobone grafts underneath the posterior facet fragment, and group 2 (n=40) included cases without a bone graft. We measured the $B{\ddot{o}}hler$ angle, Gissane angle, height, and width of the calcaneus at preoperative, postoperative, and final follow-up radiograph. We measured the sagittal rotational angle of the posterior facet fragment of preoperative computed tomography to analyze the effect and necessary conditions for bone grafting. We also reviewed the clinical results by the American Orthopaedic Foot and Ankle Society (AOFAS) scale, visual analogue scale (VAS), and any complications. Results: According to the Sanders classification, there were 3 type-II fractures, 12 type-III fractures, and 2 type-IV fractures in Group 1; whereas in Group 2, there were 26 type-II fractures, 13 type-III fractures, and 1 type-IV fracture (p=0.002). Regarding the preoperative radiologic parameters, there were significant differences in the $B{\ddot{o}}hler$ angle (p=0.006), Gissane angle (p=0.043), and rotational angle of the posterior facet fragment (p=0.001). No significant difference was observed in the preoperative calcaneal height and width, as well as postoperative radiologic parameters. There was no significant clinical difference between the two groups (p=0.546). Conclusion: We suggest that a tricortical-allobone graft may be useful in open reduction and screw fixation via the Ollier approach for displaced intra-articular calcaneal fracture with a bony defect after reduction of collapsed posterior facet fragment. This graft can contribute to the stable reduction via a small approach, even without a plate.

• Journal of the Ergonomics Society of Korea
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• v.27 no.2
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• pp.83-89
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• 2008

Study was developed the metallic plate for fixation in the femur fracture and plates has a firm place in fracture treatment. This plates can be stabilized for fracture fixation as well as biological and dynamical device. The device's designation and sizing has a optimization with bending structural stiffness and strength, known meaning that is reliable regardless of the plate by the short type and long type. The bending strength of the curved metallic long plate has to evaluate a 11,000N and the bending strength of the curved metallic short plate has to evaluate a 6,525N. This see the X-ray image of bending angle made certain of 15$^{\circ}$ at number 2 and same 82.87$^{\circ}$ at number 2, 4, 5, 7, 8, 9, 10 by outside angle, and confirmed 25.26$^{\circ}$ at number 3, 3.68$^{\circ}$ at number 6, 15.64$^{\circ}$ at number 9 by inside angle. This study shows that keep up the metallic plate for fixation in the femur fracture through X-ray Image and the device can be used to support Revision case of Hip Implant and to use a case of Hip screw compression of Hip Neck Fracture. Short plate have a wrapping of femur and long plate have to preserve a pole of femur.

• Journal of Korean Neurosurgical Society
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• v.29 no.4
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• pp.507-513
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• 2000

Objective : Posterior lumbar interbody fusion(PLIF) with transpedicular screw fixation(TPSF) have many merits in the treatment of spondylolisthesis. The aim of this study was to compare cage PLIF group(PLIF using cage and TPSF) with chip PLIF group(PLIF using autologous bone chips and TPSF) as surgical treatment of spondyloisthesis. Methods : PLIF and TPSF were performed in 44 patients with spondylolisthesis from January 1994 to December 1998. The surgical methods were divided into two groups. One group was cage PLIF(20 patients), and the other group was chip PLIF(24 patients). We analyzed the change of anterior translation, change of intervertebral space height, fusion rate, clinical outcomes, and postoperative complications in two groups. Result : There was no significant difference in reduction and maintenance of anterior translation between two groups. Intervertebral space height was increased in the two groups at immediate postoperative state. At last followup, it was decreased compared to preoperative height in chip PLIF group. In cage PLIF group, last follow-up height was decreased compared to immedate postoperative height, but it was significantly increased compared to preoperative height. Fusion rates were 70.9% and 90% in chip PLIF group and cage PLIF group, respectively. Excellent and good clinical outcomes were 79.2% in chip PLIF group and 85% in cage PLIF group, but there was no statistical significance. Complications were screw fracture(1 case), CSF leakage(1 case) in chip PLIF group and screw loosening and retropulsion of cage(1 case), CSF leakage(2 cases) in cage PLIF group. Conclusion : PLIF using cage is better than PLIF using autologous bone chips in the maintenance of intervertebral space height and fusion rate. But there is no statistical difference of the clinical outcomes between the two groups. Further studies, especially on long term follow-up, should be considered.

• Clinics in Shoulder and Elbow
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• v.18 no.2
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• pp.91-95
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• 2015

Background: Our aim was to make a comparative analysis of radiological and clinical outcomes of using either one or two interlocking distal screws on a Polarus intramedullary nail for the internal fixation of humeral shaft fractures. Methods: From January 2008 to March 2014, we enrolled 26 patients with humeral shaft fractures who were operated on using intramedullary nails. The patients were divided into 2 groups according to how many interlocking distal screws were used to lock the Polarus nail: in group 1, a single interlocking distal screw was used in 12 patients; and in group 2, double interlocking distal screws, in 14 patients. We compared the degree of recovery of the displaced fracture fragments between the two groups. To compare the nonunion and shoulder function, we assessed each patient's modified American Shoulder and Elbow Surgerns (ASES) score. Results: We found that 10 of 12 fractures achieved union in group 1, and 13 of 14 fractures, in group 2. We did not find a meaningful difference in the time to bone union between the two groups. The percentage of recovery of displaced fracture fragments until union was 66.9% for group 1 and 59.41% for group 2. At the final follow-up, we found that the scores for shoulder joint modified ASES was 78.7 for group 1 and 80.7 for group 2. Conclusions: Our results show that if locked appropriately, even a single screw on a Polarus nail can provide satisfactory radiological union and improved clinical outcome after intramedullary nailing of humeral shaft fractures.