• Journal of Korean Neurosurgical Society
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• 제61권1호
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• pp.114-119
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• 2018

Objective : The purpose of this study was to determine the feasibility of screw fixation in previously augmented vertebrae with bone cement. We also investigated the influence of cement distribution pattern on the surgical technique. Methods : Fourteen patients who required screw fixation at the level of the previous percutaneous vertebroplasty or balloon kyphoplasty were enrolled in this study. The indications for screw fixation in the previously augmented vertebrae with bone cement included delayed complications, such as cement dislodgement, cement leakage with neurologic deficits, and various degenerative spinal diseases, such as spondylolisthesis or foraminal stenosis. Clinical outcomes, including pain scale scores, cement distribution pattern, and procedure-related complications were assessed. Results : Three patients underwent posterior screw fixation in previously cemented vertebrae due to cement dislodgement or progressive kyphosis. Three patients required posterior screw fixation for cement leakage or displacement of fracture fragments with neurologic deficits. Eight patients underwent posterior screw fixation due to various degenerative spinal diseases. It was possible to insert screws in the previously augmented vertebrae regardless of the cement distribution pattern; however, screw insertion was more difficult and changed directions in the patients with cemented vertebrae exhibiting a solid pattern rather than a trabecular pattern. All patients showed significant improvements in pain compared with the preoperative levels, and no patient experienced neurologic deterioration as seen at the final follow-up. Conclusion : For patients with vertebrae previously augmented with bone cement, posterior screw fixation is not a contraindication, but is a feasible option.

• Journal of Korean Neurosurgical Society
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• 제52권4호
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• pp.353-358
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• 2012

Objective : The purpose of this study was to determine the efficacy of bone cement-augmented short segment fixation using percutaneous screws for thoracolumbar burst fractures in a background of severe osteoporosis. Methods : Sixteen patients with a single-level thoracolumbar burst fracture (T11-L2) accompanying severe osteoporosis treated from January 2008 to November 2009 were prospectively analyzed. Surgical procedures included postural reduction for 3 days and bone cement augmented percutaneous screw fixation at the fracture level and at adjacent levels without bone fusion. Due to the possibility of implant failure, patients underwent implant removal 12 months after screw fixation. Imaging and clinical findings, including involved vertebral levels, local kyphosis, canal encroachment, and complications were analyzed. Results : Prior to surgery, mean pain score (visual analogue scale) was 8.2 and this decreased to a mean of 2.2 at 12 months after screw fixation. None of the patients complained of pain worsening during the 6 months following implant removal. The percentage of canal compromise at the fractured level improved from a mean of 41.0% to 18.4% at 12 months after surgery. Mean kyphotic angle was improved significantly from $19.8^{\circ}$ before surgery to 7.8 at 12 months after screw fixation. Canal compromise and kyphotic angle improvements were maintained at 6 months after implant removal. No significant neurological deterioration or complications occurred after screw removal in any patient. Conclusion : Bone cement augmented short segment fixation using a percutaneous system can be an alternative to the traditional open technique for the management of selected thoracolumbar burst fractures accompanied by severe osteoporosis.

• Clinics in Shoulder and Elbow
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• 제23권3호
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• pp.152-155
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• 2020

Periprosthetic fracture after total elbow replacement surgery is a difficult complication to manage, especially when it comes together with implant loosening. If stem revision and internal fixation of the periprosthetic fracture are performed simultaneously, this would be a very challenging procedure. Most of total elbow replacement implants are cemented type. Cement usage at periprosthetic fracture site may interfere healing of fractured site. Authors underwent internal fixation with use of locking plate and cerclage wire for periprosthetic fracture, allogenous fibular strut bone inserted into the humerus intramedullary canal allowing the fractured site to be more stable without cement usage. At 10-month follow-up, the complete union and good clinical outcome was achieved. We present a novel technique for treating periprosthetic fracture with implant loosening after total elbow replacement surgery, using intramedullary allogenous fibula strut bone graft.

• The Korean Journal of Physiology and Pharmacology
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• 제18권2호
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• pp.103-108
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• 2014

Head restraining is an experimental technique that firmly secures the animal's head to a fixation apparatus for the precise control and sensing of behaviors. However, procedural and surgical difficulties and limitations have been obstructing the use of the technique in neurophysiological and behavioral experiments. Here, we propose a novel design of the head-restraining apparatus which is easy to develop and convenient for practical use. Head restraining procedure can be completed by sliding the head mounter, which is molded by dental cement during implantation surgery, into the port, which serves as matching guide rails for the mounter, of the fixation bar. So neither skull-attached plates nor screws for fixation are needed. We performed intracranial self stimulation experiment in rats using the newly designed device. Rats were habituated to acclimatize the head-restraint environment and trained to discriminate two spatially distinguished cues using a customized push-pull lever as an operandum. Direct electrical stimulation into the medial forebrain bundle served as reward. We confirmed that head restraining was stable throughout experiments and rats were able to learn to manipulate the lever after successful habituation. Our experimental framework might help precise control or sensing of behavior under head fixed rats using direct electrical brain stimulation as a reward.

• The Journal of Advanced Prosthodontics
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• 제12권4호
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• pp.233-238
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• 2020

PURPOSE. This study aims to compare the marginal fitness of two types of implant-supported fixed dental prosthesis, i.e., cementless fixation (CL.F) system and cement-retained type. MATERIALS AND METHODS. In each group, ten specimens were assessed. Each specimen comprised implant lab analog, titanium abutment fabricated with a 2-degree tapered axial wall, and zirconia crown. The crown of the CL.F system was retained by frictional force between abutment and relined composite resin. In the cement-retained type, zinc oxide eugenol cement was used to set crown and abutment. All specimens were sterilized with ethylene oxide, immersed in Prevotella intermedia culture in a 50 mL tube, and incubated with rotation. After 48 h, the specimens were washed thoroughly before separating the crown and abutment. The bacteria that penetrated into the crown-abutment interface were collected by washing with 500 µL of sterile saline. The bacterial cell number was quantified using the agar plate count technique. The BacTiter-Glo Microbial Cell Viability Assay Kit was used to measure bacterial adenosine triphosphate (ATP)-bioluminescence, which reflects the bacterial viability. The t-test was performed, and the significance level was set at 5%. RESULTS. The number of penetrating bacterial cells assessed by colony-forming units was approximately 33% lower in the CL.F system than in the cement-retained type (P<.05). ATP-bioluminescence was approximately 41% lower in the CL.F system than in the cement-retained type (P<.05). CONCLUSION. The CL.F system is more resistant to bacterial penetration into the abutment-crown interface than the cement-retained type, thereby indicating a precise marginal fit.

• Structural Engineering and Mechanics
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• 제66권1호
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• pp.37-43
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• 2018

In orthopedic surgery and in particular in total hip arthroplasty, the implant fixation is carried out using a surgical cement called polymethylmethacrylat (PMMA). This cement has to insure a good adhesion between implant and bone and a good load distribution to the bone. By its fragile nature, the cement can easily break when it is subjected to a high stress gradient by presenting a craze zone in the vicinity of inclusion. The focus of this study is to analyze the effect of inclusion in some zone of cement in which the loading condition can lead to the crack opening leading to their propagation and consequently the aseptic loosening of the THR. In this study, the fracture behavior of the bone cement including a strange body (bone remain) from which the onset of a crack is supposed. The effect of loading condition, the geometry, the presence of both crack and inclusion on the stress distribution and the fracture behavior of the cement. Results show that the highest stresses are located around the sharp tip of bony inclusion. Most critical cracks are located in the middle of the cement mantle when they are subjected to one leg standing state loading during walking.

• Clinics in Shoulder and Elbow
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• 제13권2호
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• pp.237-243
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• 2010

목적: 관절경적 회전근 개 봉합술 시 뼈에 봉합 나사못을 안정적으로 고정하는 것이 중요하다. 그러나 고령의 환자에서 상완골 결절부위에 골다공증이 있는 경우 봉합 나사못이 빠지거나 고정이 불안정할 수 있다. 이에 저자들은 관절경적 회전근 개 봉합술에서 봉합 나사못의 고정 실패시 골 시멘트를 이용한 봉합 나사못 구멍 보강 기법을 소개하고 그 결과를 보고하고자 한다. 대상 및 방법: 2005년부터 2009년까지 관절경적 회전근 개 봉합술을 시행받은 223명 중 골 시멘트로 봉합 나사못 구멍을 보강했던 15명을 대상으로 하였다. 모두 여자로 평균 65 (49~77)세였고, 평균 추시 기간은 16 (6~32)개월 이었다. 주사기를 이용해 골 시멘트를 걸쭉한 액상의 상태에서 봉합 나사못 구멍에 주입한 후 압박기로 압력을 가하였으며 항아리 모양의 시멘트 맨틀을 만들도록 노력하였다. 시멘트가 굳어가기 시작할 무렵 봉합 나사못을 구멍에 삽입하였다. 최종 임상적 평가는 시각척도 통증 점수, 능동적 관절 운동범위, age-sex matched Constant score, UCLA score 등을 이용하여 분석하였다. 결과: 수술 전 촬영한 방사선 사진상, 상완골 대결절부의 낭종성 변화 또는 피질골의 위축 등이 전 예에서 보였다. 최종 추시 방사선 사진상 시멘트 음영의 변화는 볼 수 없었으며, 충진된 시멘트는 원래의 형태를 그대로 유지하였다. UCLA score는 평균 31점 (28~35점) 이었으며 최우수 6예, 우수 8예이었으며 1예는 보통의 결과를 보였다 (p-value 0.008). Age-sex matched Constant score는 평균 90점 (74~98점)으로 상승하였다 (p-value 0.008). 결론: 관절경적 회전근 개 봉합술에서 상완골 대결절부의 골위축이 있는 경우에도 골 시멘트를 이용한 봉합 나사못 구멍 보강술에 의하여 관절경적 봉합술을 시행할 수 있었으며 골 시멘트의 사용이 수술 후 결과에 부정적 영향을 미치지 않는 것으로 보인다.

• 한국임상수의학회지
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• 제26권4호
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• pp.359-361
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• 2009

체중 25.2 kg 2년령 암컷 알라스카 말라뮤트 개가 교통사고 후 한강 동물병원에 내원하였다. 신체 검사에서 심한 유연과 견치 탈구를 보였으며 방사선 사진에서 앞쪽 하악골 골절이 관찰 되었다. 와이어링과 polymethyl methacrylate을 이용한 외고정을 실시하였다. 수술 7주 후 방사선 사진 검사에서 잘 발달 된 가골 형성이 골절 부위 피질에서 관찰 되었다. 수술 7주 후 핀이 제거 되었으며 정상적인 저작 운동을 관찰 할 수 있었다.

• 한국표면공학회지
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• 제29권2호
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• pp.81-92
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• 1996

The cementless fixation of bone ingrowth by porous coatings on artificial hip joint prostheses are replacing polymethylmethacrylate(PMMA) bone cement fixations. However, the major interests in the field of porous metal coating are environmental corrosivity accelerated by metal ion release, deterioration in the mechanical property of the coating, and the mechanical failure of the coatings as well as the substrate. Therefore, the selection of right materials for coatings and the development of porous coating techniques must be accomplished. Because of the existing problems in Ti and Ti alloys which are used extensively, this study is focused on the plasma spraying technique for coating on super stainless steel substrate. In order to determine the optimum conditions which satisfy the requirement for the porous coatings, under the plasma spraying, we selected the experimental parameters which extensively influenced on the characteristics of the coating through the pre-examination. Spray distance has been selected among 120, 160, and 200mm and primary gas flow rate among 70, 100, and 130 SCFH. Current and secondary gas($H_2$) flow rate was fixed at 400A, and 15 SCFH respectively. To understand the characteristics of the coatings, surface morphology, cross-sectional micro-structure, surface roughness, residual stress, and corrosion resistance were elucidated and the best conditions for the bone ingrowth improvement on artificial hip joint prostheses were found.

• Journal of Korean Neurosurgical Society
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• 제40권2호
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• pp.90-94
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• 2006

Objective : Acute vertebral burst fractures warrant extensive fixation and fusion on the spine. Osteoplasty [vertebroplasty with high density resin without vertebral expansion] has been used to treat osteoporotic vertebral compression fractures. We report our experiences with osteoplasty in acute vertebral burst fractures. Methods : Twenty-eight cases of acute vertebral burst fracture were operated with osteoplasty. Eighteen patients had osteoporosis concurrently. Preoperative MRI was performed in all cases to find fracture level and to evaluate the severity of injury. Preoperative CT revealed burst fracture in the series. The patients with severe ligament injury or spinal canal compromise were excluded from indication. Osteoplasty was performed under local anesthesia and high density polymethylmethacrylate[PMMA] was injected carefully avoiding cement leakage into spinal canal. The procedure was performed unilaterally in 21 cases and bilaterally in 7 cases. The patients were allowed to ambulate right after surgery. Most patients discharged within 5 days and followed up at least 6 months. Results : There were 12 men and 16 women with average age of 45.3[28-82]. Five patients had 2 level fractures and 2 patients had 3 level fractures. The average injection volume was 5.6cc per level Average VAS [Visual Analogue Scale] improved 26mm after surgery. The immediate postoperative X-ray showed 2 cases of filler spillage into spinal canal and 4 cases of leakage into the retroperitoneal space. One patient with intraspinal leakage was underwent the laminectomy to remove the resin. Conclusion : Osteoplasty is a safe and new treatment option in the burst fractures. Osteoplasty with minimally invasive technique reduced the hospital stay and recovery time in vertebral fracture patients.