• Proceedings of the Korean Society of Veterinary Clinics Conference
• /
• 2007.05a
• /
• pp.162-162
• /
• 2007

• Journal of Korean Foot and Ankle Society
• /
• v.19 no.1
• /
• pp.11-17
• /
• 2015

Purpose: To report the radiographic and clinical results of 6.5 mm cancellous full threaded buttress screw or Steinmann pin fixation to maintain a reduction of calcaneal posterior facet depression fracture. Materials and Methods: From June 2009 to June 2012, 50 consecutive cases with calcaneal joint depression fracture that underwent open reduction and screw or pin fixation were enrolled in this study. A 6.5 mm cancellous full threaded screw was inserted from the posteroinferior aspect of the calcaneal tuberosity to the posterior facet (group A) or Steinman pin was inserted from the posterosuperior aspect of the calcaneal tuberosity to the calcaneocuboidal joint (group B). Both preoperative and postoperative Bohler and Gissane angles were measured radiographically, and American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale on the final follow-up were assessed. Results: The mean age of patients was 44.1 years, and the mean follow-up period was 27.2 months. According to the Sanders classification, 28 cases were type II and 22 cases were type III. In Sanders type II, Bohler and Gissane angles improved significantly from $10.1^{\circ}$ and $126.2^{\circ}$ preoperatively to $27.2^{\circ}$ and $117.1^{\circ}$, respectively, in the immediate postoperative radiograph, and at the final follow-up, $26.6^{\circ}$ and $118.6^{\circ}$, respectively. In Sanders type III, Bohler and Gissane angles improved significantly from $5.0^{\circ}$ and $129.8^{\circ}$ to $29.9^{\circ}$ and $119.3^{\circ}$, respectively, in the immediate postoperative radiograph, and $26.9^{\circ}$ and $120.2^{\circ}$ at the final follow-up. All cases achieved bony union, and the average period until complete union was 13.3 weeks. AOFAS ankle-hindfoot scale was 82.6 in Sanders type II and 77.3 in Sanders type III at the final follow-up. Conclusion: A 6.5 mm cancellous full threaded buttress screw or Steinman pin fixation is a noninvasive treatment method with a merit of being able to maintain the bearing capacity of the posterior facet comparable to plate fixation.

• Journal of the Korean Society for Precision Engineering
• /
• v.33 no.11
• /
• pp.937-941
• /
• 2016

Stand-alone cervical cage consists of a PEEK body, Ti plate, and screw, which are configured as a single-piece. Through a single operation, this implantable medical device is capable of completely fixing the cervical vertebral body. For example, instead of a plate, which is normally used, the intervertebral disc is removed and replaced with a cervical cage. It should be noted that in Korea, KFDA guidelines for a stand-alone cervical cage have not yet been suggested. Therefore, the aim of this study is to present the systematic study of the static compression test, static torsion test, dynamic compression test, and expulsion test. Further, the test method is designed to refer to the ASTM standard and relative literature.

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2006.09a
• /
• pp.493-494
• /
• 2006

Chip breaker of cutting tool is an important feature to enhance cutting performance. Powder injection molding process was used to produce a triangular-shape cermet grooving insert which has three chip breakers. Attrition milled cermet powders were mixed with wax-based binder system in continuous twin screw extruder. Three-plate injection mold with slide cores was used to produce injection-molded parts. After molding, solvent and thermal debinding was carried out. Sintering was conducted in a batch furnace with a graphite heater. The sintered parts satisfy the requirements of dimensional tolerances and material properties.

• Journal of Korean Neurosurgical Society
• /
• v.51 no.3
• /
• pp.135-140
• /
• 2012

Objective : To evaluate radiographic results of anterior fusion methods in two-level cervical disc disease : tricortical autograft and plate fixation (ACDF-AP), cage and plate fixation (ACDF-CP), stand-alone cage (ACDF-CA), and corpectomy and plate fixation (ACCF). Methods: The numbers of patients were 70 with a minimum 6 month follow-up (ACDF-AP : 12, ACDF-CP : 27, ACDF-CA : 15, and ACCF : 16). Dynamic simple X-ray and computed tomography were evaluated preoperatively, postoperatively, 6 month, and at the final follow-up. The fusion and subsidence rates at the final were determined, and global cervical lordosis (GCL), cervical range of motion, fused segment angle (FSA), and fused segment height (FSH) were analyzed. Results: Nonunion was observed in 4 (25%) patients with ACDF-CA, 1 (8%) patient with ACDF-AP, 1 (4%) patient with ACDF-CP. The number of loss of FSH (%) more than 3 mm were 2 patients (16%) in ACDF-AP, 3 patients (11%) in ACDF-CP, 5 patients (33%) in ACDF-CA, and 3 patients (20%) in ACCF. The GCL was decreased with ACDF-CA and increased with others. The FSA was increased with ACDF-AP, ACDF-CP, and ACCF, but ACDF-CA was decreased. At the final follow-up, the FSH was slightly decreased in ACDF-CP, ACDF-AP, and ACCF, but ACDF-CA was more decreased. Graft related complication were minimal. Screw loosening, plate fracture, cage subsidence and migration were not identified. Conclusion: ACDF-CP demonstrated a higher fusion rate and less minimal FSH loss than the other fusions in two-level cervical disc disease. The ACDF-AP and ACCF methods had a better outcome than the ACDF-CA with respect to GCL, FSA, and FSH.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.42
• /
• pp.6.1-6.6
• /
• 2020

Background: Various types of miniplates have been developed and used for the reduction of facial bone fractures. We introduced Yang's Keyhole (YK) plate, and reported on its short-term stability. The purpose of this study was to evaluate the long-term stability of the YK plate, as a follow-up study, by examining the patients who had used the YK plate among the patients with the reduction of mandible fractures and who visited for plate removal. Methods: We reviewed the medical records of 16 patients who underwent mandibular fracture fixation using a YK plate (group I) and 17 patients who underwent mandibular fracture fixation using a conventional plate (group II). Assessment was then made on malunion, occlusal stability, discomfort during the application, and clinical symptoms. Results: From January 2015 to December 2017, a total of 36 patients underwent mandibular fracture surgery using a YK plate. A total of 16 patients received plate removal. Among them, 15 were male and 1 female. The average age was 26 years. The applied surgical sites were the 12 on mandibular angle, 4 on mandibular symphysis, and 2 on subcondyle. The application period of YK plate was an average of 335 days. During the same period, 45 people underwent surgery on the conventional plate. A total of 17 patients received plate removal. Among them, 15 were male and 2 females. The average age was 36 years. The applied surgical sites were the 8 on mandibular angle, 4 on mandibular symphysis, and 2 on subcondyle. The application period of the conventional plate was an average of 349 days. No malocclusion occurred at the time of removal, and occlusion was stable. No patient complained of joint disease or discomfort. Conclusion: The YK plate system, in which the screw was first inserted and the plate was applied, for clinical convenience did not cause any particular problem and no significant difference from the conventional plate.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.29 no.5
• /
• pp.265-271
• /
• 2003

Skeletal relapse is known as a complication following orthognathic surgery of mandibular prognathism and occurring during intermaxillary fixation period. Therefore relapse of teeth and skeleton during intermaxillary fixation period is considered as a important problem of orthognathic surgery. In this study, cephalolateral radiographs taken at pre-operation, immediate post-operation and after release of intermaxillary fixation were measured for evaluation of dental and skeletal relapse in 30 cases. The cases were classified as screw fixation group and plate fixation group, then we compared magnitude of dental and skeletal changes of each group. The results were as follows 1. The $\underline{1}$ SN angle increased at immediate post-operation with a mean value of $0.12^{\circ}$ and at intermaxillary fixation period with a mean value of $0.43^{\circ}$ (p>0.05). 2. The $\overline{1}$ MP angle decreased with a mean value of $0.14^{\circ} at immediate post-operation and with a mean value of $1.28^{\circ} during intermaxillary fixation period but there were not significant difference(p>0.05). 3. There were not significant difference in magnitude of dental position changes between screw fixation group and plate fixation group(p>0.05). 4. Gonial angle increased with a mean value of $0.62^{\circ} during intermaxillary fixation period. Each group showed changes of gonial angle during intermaxillary fixation period but there were not significant difference(p>0.05).

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.25 no.5
• /
• pp.8-14
• /
• 2021

Post-tensioned prestressed concrete members experience immediate prestress losses as well as time-dependent prestress losses such as creep, dry shrinkage and relaxation. In addition, the stress of the upper and lower parts of the member changes due to the change in dead load due to the replacement of the upper slab and/or pavement. Such changes in fiber stress may affect the safety of the member, and it is necessary to adjust the prestressing force. Therefore, in this study, a screw type of re-tensioning post-tension kit is proposed, and it is verified that the safety against load and the stability against strain are satisfied through the load transfer test specified in EAD160004 and KCI-PS101.

• Journal of Korean Foot and Ankle Society
• /
• v.9 no.1
• /
• pp.99-104
• /
• 2005

Purpose: The purpose of this study was to investigate usefulness of locking compression plate (LCP) as an open reduction technique by evaluating clinical results obtained from the patients with lateral malleolar fracture treated by internal fixation using LCP after open reduction. Materials and Methods: Among the patients with lateral malleolar fracture, the 28 patients who were treated by internal fixation using Locking compression plate after an open reduction and were able to be followed up for more than 6 months were included in this study. Final postoperative evaluation was done based on the Meyer's clinical and radiologic evaluation system. Results: All cases achieved anatomical reduction and fixation of the reduction postoperatively. 28 minutes were taken meaningly from the incision to the fixation of LCP plate after the anatomical reduction. Everage bony union time was 8.2 weaks, and the result was excellent in 23 cases (82%), good in 5 cases (17%) and poor result was abscent according to the criteria of Meyer et al. One case of post traumatic arthritis and one case of superficial infection on the operation site were found, but non-union, delayed union and malunion were not occurred. Conclusion: The internal fixation after open reduction using LCP is an effective treatment method in treating lateral malleolar fracture of the ankle since it offers advantages including easy application and a greater stability due to its capability of maintaining exact anatomical reduction even though the screw does not penetrate the medial cortex of fibular to add the stability and rigidity of the fixation.

• Composites Research
• /
• v.23 no.1
• /
• pp.1-7
• /
• 2010

In this paper, finite element analyses for estimating the behavior of fractured femur just after the operation were carried out by using ABAQUS 6.71. A stainless steel bone plate and composite bone plates with various stacking angles were considered to find out the effect of bone plate properties on bone fracture healing. In order to simulate the actual state, contact conditions between the plate and bone and fractured bones were imposed on the finite element models and the whole analysis was divided by two steps; screw fastening step and load bearing step. The stress and strain distributions at the fracture site for the cases of the stainless steel and composite bone plates were analyzed and compared with. From the analyses it was found that the composite bone plate had potential advantages for effective bone fractures healing relieving stress shielding effect.