• Journal of Veterinary Clinics
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• v.37 no.4
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• pp.217-222
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• 2020

A 3-year-old male Thoroughbred serving as a Korean racehorse named RAON PORTEOUS presented with acute lameness concomitant with edema and fever in the right carpal joint after completing a horse race. Through radiological examination using lateromedial oblique, flexed lateromedial oblique and dorsopromixal-dorsodistal oblique views, the horse was diagnosed with a slab fracture in the 3^rd carpal bone of right forelimb. The fracture was surgically approached and corrected by applying 4.5 mm leg screw fixation during surgery. At eight months post-surgery, the horse was able to return to racing and has had successful racing performances with two wins and several prizes in the last 8 months. This is the first reported case of the successful use of lag screw fixation surgery in Korea with the horse showing complete recovery from a severe injury that is often considered fatal in a racehorse.

• Journal of Korean Neurosurgical Society
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• v.37 no.3
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• pp.201-206
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• 2005

Objective: To evaluate the accuracy and safety of C1-C2 transarticular screw insertion, we retrospectively review surgical records and postoperative radiological findings. Methods: From January 2001 to October 2003, the C1-C2 transarticular screw fixation and posterior wiring with iliac bone grafts was performed in 16 patients. 6 patients had rheumatoid arthritis which caused cervical instability, 3 patients had os odontoideum, 3 patients had type 2 odontoid process fracture, 3 patients had traumatic transverse ligament injury and 1 patients who had been managed with C1-C2 wire fixation had psoriatic arthritis. Results: Osseous fusion was documented in 15 patients(93.8%). Only one patient was recorded screw loosening because of postoperative infection. One patient had only one screw placed because of abnormal anatomical structure, one patients was breakage of a Kirschner wire, and one screw was medial location to lateral mass of C1, but clinical results was excellent and radiological instability was not noted. Conclusion: The author's experience demonstrates that C1-C2 transarticular screw fixation with wired bone graft is a safe procedure with higher fusion rate but precaution is needed to avoid the neural damage, vertebral artery injury, and hardware failure.

• Journal of Trauma and Injury
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• v.35 no.1
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• pp.12-18
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• 2022

Purpose: Pedicle screw fixation provides 3-column stabilization, multidimensional control, and a higher rate of interbody fusion. Although computed tomography (CT) is recommended for the postoperative assessment of pedicle screw fixation, its use is limited due to the radiation exposure dose. The purpose of this preliminary retrospective study was to assess the clinical usefulness of low-dose mobile cone-beam CT (CBCT) for the postoperative evaluation of pedicle screw fixation. Methods: The author retrospectively reviewed postoperative mobile CBCT images of 15 patients who underwent posterior pedicle screw fixation for spinal disease from November 2019 to April 2020. Pedicle screw placement was assessed for breaches of the bony structures. The breaches were graded based on the Heary classification. Results: The patients included 11 men and four women, and their mean age was 66±12 years. Of the 122 pedicle screws, 34 (27.9%) were inserted in the thoracic segment (from T7 to T12), 82 (67.2%) in the lumbar segment (from L1 to L5), and six (4.9%) in the first sacral segment. Although there were metal-related artifacts, the image of the screw position (according to Heary classification) after surgery could be assessed using mobile CBCT at all levels (T7-S1). Conclusions: Mobile CBCT was accurate in determining the location and integrity of the pedicle screw and identifying the surrounding bony structures. In the postoperative setting, mobile CBCT can be used as a primary modality for assessing the accuracy of pedicle screw fixation and detecting postoperative complications.

• Journal of Korean Neurosurgical Society
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• v.29 no.1
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• pp.95-100
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• 2000

Objective : Posterior transarticular screw fixation is known to be one of the best surgical method for the atlantoaxial instability. We assessed the complication and operative risk in 15 patients. Patients and Methods : Between January 1997 and April 1998, 15 patients suffering from this condition were admitted to our institution. Atlantoaxial instability was caused by C1 or C2 fractures in 11, rheumatoid arthritis in 2, and os odontoideum in 2. This technique was used in the treatment of 13 patients and 2 patients was used in sublaminar wire fixation only. Bilateral C1-C2 screws were placed in 11 patients ; 2 patients had only one screw placed becauce of an anomalous vertebral artery and axial destruction. Follow-up period ranged from 5 to 20 months. Results : Most screws were positioned satisfactorily. One screw was malpositioned. No patients had neurological complications. Conclusion : Rigidly fixating C1-C2 instability with transarticular screws showed a significantly higher fusion rate than that achieved using wired grafts alone. The risk of screw malpositioning and catastrophic vascular or neural injury is small and can be minimized by assessing the position of the transverse foramen on preoperative computed tomographic scans and by correctly using intraoperative fluoroscopy and surgeon's precaution.

• Journal of Korean Foot and Ankle Society
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• v.24 no.2
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• pp.94-97
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• 2020

Purpose: Fatigue breakage of cortical screws sometimes occurs after syndesmosis fixation, regardless of the period of screw retention. This study compared the fatigue strength of a novel screw design to conventional cortical screws in the fixed state of syndesmosis. Materials and Methods: Twelve sawbone models were tested mechanically to determine the fatigue strength of three screw designs. The first group was composed of cortical screws, while the second and third groups were newly-designed screws. The second group was composed of screws with a 2.4-mm diameter thread-free portion of the mid-shank while the third group had a 2.0-mm diameter thread-free mid-shank. A 400 N load was applied repetitively to a fibula model and the number of cycles until screw failure was recorded. Four screws from each group were tested, giving a total of 12 fatigue tests. Results: The average cycles until screw failure for groups 1, 2, and 3 were 8,134, 63,186, and 2,581, respectively. The second group showed the highest fatigue strength (p=0.018). The other two screw designs showed similar fatigue strength (p=0.401). Conclusion: New screw designs with a thread-free portion in the mid-shank could reduce the occurrence of fatigue breakage after syndesmosis fixation.

• Journal of the Korean Orthopaedic Association
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• v.55 no.5
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• pp.405-410
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• 2020

Purpose: Pedicle screw insertion has been traditionally used as a surgical treatment for degenerative lumbar spine disease. As an alternative, the cortical-bone trajectory screw allows less invasive posterior lumbar fixation and excellent mechanical stability, as reported in several biomechanical studies. This study evaluated the clinical and radiological results of a case of early failure of cortical-bone screw fixation in posterior fixation and union after posterior decompression. Materials and Methods: This study examined 311 patients who underwent surgical treatment from 2013 to 2018 using cortical orbital screws as an alternative to traditional pedicle screw fixation for degenerative spinal stenosis and anterior spine dislocation of the lumbar spine. Early fixation failure after surgery was defined as fixation failure, such as loosening, pull-out, and breakage of the screw on computed tomography (CT) and radiographs at a follow-up of six months. Results: Early fixation failure occurred in 46 out of 311 cases (14.8%), screw loosening in 46 cases (14.8%), pull-out in 12 cases (3.9%), and breakage in four cases (1.3%). An analysis of the site where the fixation failure occurred revealed the following, L1 in seven cases (15.2%), L2 in three cases (6.5%), L3 in four cases (8.7%), L4 in four cases (8.7%), L5 in four cases (8.7%), and S1 in 24 cases (52.2%). Among the distal cortical bone screws, fixation failures such as loosening, pull-out, and breakage occurred mainly in the S1 screws. Conclusion: Cortical-bone trajectory screw fixation may be an alternative with comparable clinical outcomes or fewer complications compared to conventional pedicle screw fixation. On the other hand, in case with osteoporosis and no anterior support structure particularly at L5-S1 fusion sites were observed to have result of premature fixation failures such as relaxation, pull-out, and breakage.

• Journal of Korean Neurosurgical Society
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• v.29 no.11
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• pp.1469-1475
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• 2000

Objective : The goal of this study was to evaluate the clinical outcome of the posterior C1-2 transarticular screw fixation without C1-2 sublaminar wiring in atlantoaxial instability. Methods : Between Apr. 1995 and Feb. 2000, we used this technique in treat randomly selected 17 patients (11 men, 6 women) who had atlantoaxial instability. The causes of instability were : type II-A odontoid process fracture(10 cases) ; type II-P odontoid process fracture(1 case) ; Os odontoideum(2 cases) ; transverse ligament laxity due to rheumatoid disease(1 case) ; and, transverse ligament injury without bone fracture(3 cases). All cases were operated with posterior C1-2 transarticular screw fixation with 3.5mm cortical screw and interlaminar iliac graft without sublaminar wire fixation. The mean follow-up period was 28 months(5 to 58 months) and the mean age at the time of operation was 41 years(15 to 68 years). All Patients were allowed to ambulate with Philadelphia neck collar on the first post-operation day. Results : Bony fusion was successfully achieved in all cases demonstrated at 3-month follow-up studies. There was no operative mortality or morbidity. Conclusion : The authors conclude that the posterior transarticular screw fixation without C1-2 sublaminar wiring provide adequate stability with high bony union rate in atlantoaxial instability of various causes.

• Clinics in Shoulder and Elbow
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• v.13 no.1
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• pp.127-131
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• 2010

Purpose: The authors used arthroscopy-assisted percutaneous reduction and cannulated screw fixation rather? than conventional arthrotomy for displaced glenoid fracture. Materials and Methods: We used arthroscopy assisted reduction and screw fixation for a 66 year old man who had a clavicle fracture, a displaced glenoid fracture and a scapula fracture. Results: At 9 months postoperatively, the patient had recovered full range of motion and was not inconvenienced by the surgery. Removal of the implant was done 12 months post-operatively under general anesthesia. Conclusion: The advantages of arthroscopy-assisted percutaneous screw fixation are less pain and less bleeding, shorter hospital stay and earlier rehabilitation. Arthroscopic percutaneous screw fixation for a displaced glenoid fracture seems to be a good alternative treatment method.

• Clinics in Shoulder and Elbow
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• v.19 no.2
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• pp.105-109
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• 2016

Arthroscopy is recognized as an important adjunct in treatment of intra-articular fractures. The author reports on successful treatment of a displaced transverse glenoid cavity fracture, reduced and fixed with arthroscopic assist, using two cannulated screws perpendicular to the fracture surface, in a patient with frail chest. One screw passed through the Neviaser portal, and the other screw passed through the base of the coracoid process. Arthroscopy assisted reduction and 2 cannulated screw fixation through the Neviaser portal and coracoid base appears to be a good method for treatment of transverse glenoid fractures.

• Journal of Korean Neurosurgical Society
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• v.52 no.2
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• pp.120-125
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• 2012

Objective : To investigate the feasibility of C1 lateral mass screw and C2 pedicle screw with polyaxial screw and rod system supplemented with miniplate for interlaminar fusion to treat various atlantoaxial instabilities. Methods : After posterior atlantoaxial fixation with lateral mass screw in the atlas and pedicle screw in the axis, we used 2 miniplates to fixate interlaminar iliac bone graft instead of sublaminar wiring. We performed this procedure in thirteen patients who had atlantoaxial instabilities and retrospectively evaluated the bone fusion rate and complications. Results : By using this method, we have achieved excellent bone fusion comparing with the result of other methods without any complications related to this procedure. Conclusion : C1 lateral mass screw and C2 pedicle screw with polyaxial screw and rod system supplemented with miniplate for interlaminar fusion may be an efficient alternative method to treat various atlantoaxial instabilities.