• 대한의용생체공학회:의공학회지
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• 제38권1호
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• pp.9-15
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• 2017

Recently, flexible cages have been introduced in an attempt to absorb and reduce the abnormal load transfer along the anterior parts of the spine. They are designed to be used with the pedicle screw systems to allow some mobility at the index level while containing ROM at the adjacent level. In this study, a finite element (FE) study was performed to assess biomechanical efficacies of the flexible cage when combined with pedicle screws with flexible rods. The post-operated models were constructed by modifying the L4-5 of a previously-validated 3-D FE model of the intact lumbar spine (L2-S1): (1) Type 1, flexible cage only; (2) Type 2, pedicle screws with flexible rods; (3) Type 3, interbody fusion cage plus pedicle screws with rigid rods; (4) Type 4, interbody fusion cage plus Type 2; (5) Type 5, Type 1 plus Type 2. Flexion/extension of 10 Nm with a compressive follower load of 400N was applied. As compared to the Type 3 (62~65%) and Type 4 (59~62%), Type 5 (53~55%) was able to limit the motion at the operated level effectively, despite moderate reduction at the adjacent level. It was also able to shift the load back to the anterior portions of the spine thus relieving excessively high posterior load transfer and to reduce stress on the endplate by absorbing the load with its flexible shape design features. The likelihood of component failure of flexble cage remained less than 30% regardless of loading conditions when combined with pedicle screws with flexible rods. Our study demonstrated that flexible cages when combined with posterior dynamic system may help reduce subsidence of cage and degeneration process at the adjacent levels while effectively providing stability at the operated level.

• Journal of Korean Neurosurgical Society
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• 제29권6호
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• pp.763-771
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• 2000

Objectives : Thoracolumbar burst fractures(TBLF) result in not only compressive deformity of vertebral body but also spinal cord compression by bony fragments. Many thoracolumbar burst fractures demand both anterior decompression and intervertebral fusion. Most of spinal surgeons use anterior instrumentation for anteior intervertebral bony fusion. The use of Z-plate has been increased recently, however there has been only a few reports regarding its clinical long-term strength. We studied nineteen patients with TBLF to find out the long-term stability of Z-plate. Methods : We have operated 19 patients from March 1996 to August 1998. They were treated with anterior decompression through either a transthoracic, retroperitoneal extrapleural or retroperitoneal approach. Retropulsed bony fragments were removed completely by corpectomy. Iliac bone graft was used for interbody fusion in all of the cases. They were evaluated by plain X-ray films including flexion and extention lateral films. Cobbs angle was used to evaluate kyphotic and lateral wedging deformity. Results : Burst fractured sites were T11 in two, three T12, nine L1, and five L2. Mean follow-up duration was fifteen months. Preoperative average kyphotic angle was 23.7 degree. Immediate postoperative kyphotic angle was 10.2 degree. Follow-up resluts of average kyphotic angles revealed 14 degrees. Four patients(21%), including two spinal 3-column injury, showed increasement of kyphotic angle more than 5 degree or breakage of intrumentation. Two patients showed the difference of kyphotic angle more than 3 degree. Five patients(26%) revealed lateral wedging deformity more than 3 degrees. Postoperative complications were two meralgia parestheticas, one pulmonary atelectasis and two donor site infections. Four of the eight patients, who initially showed incomplete spinal cord deficits, were nerologically improved by Frankel's grade. Conclusion : Z-plate fixation and iliac bone graft after anterior decompression in thoracolumbar burst fractures is a safe and easy method. Immediate postoperative results revealed excellent correction of posttraumatic kyphosis, but long-term follow-up evalution showed insufficient strength. Therefore we believe that use of Z-plate should be carefully decided, especially in the case of large lumbar fracture or 3-column injury.

• 대한정형외과학회지
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• 제52권1호
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• pp.83-91
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• 2017

목적: 고령 환자의 흉요추부 유합에서 척추경 나사못과 함께 사용된 원위부 갈고리의 임상적 결과를 알아보고자 하였다. 대상 및 방법: 본 연구는 다기관 후향적 연구로, 2008년부터 2015년까지 65세 이상 환자에서 흉요추부 병변으로 전방 지지와 함께 장분절의 후방 유합을 시행한 20명을 대상으로 하였다. 이 중에서 척추경 나사못 및 원위부 갈고리를 이용한 10명을 갈고리 군으로, 원위부 나사못 없이 척추경 나사못만을 이용한 10명을 나사못 군으로 나누어 술 후 1년째 원위부 나사못의 뽑힘 및 후방 이탈의 정도를 비교하였다. 결과: 환자들의 평균 나이는 72.4세(65-83세), 유합 분절은 평균 4.6분절(3-6분절)이었다. 두 군 간의 비교에서 나이, 성별, 원인 질환, 요추 및 근위 대퇴골 골밀도, 골다공증 유무, 유합 분절 수는 두 군 간에 유의한 차이가 없었다(p≥0.05). 술 후 1년 사이에서 발생한 원위부 나사못의 후방 이탈을 평가한 지표는 두 군 간에 유의한 차이가 있었다(p<0.05). 원위부 나사못의 후방 이탈은 총 6명에서 발견되었으며, 이는 모두 원위부 갈고리를 보강하지 않은 나사못 군에서만(60%, 6/10) 관찰되었고 갈고리 군에서는 없었다. 결론: 고령 환자의 흉요추부 장분절 유합에서 원위부 갈고리의 사용은 나사못의 후방 이탈과 관련된 합병증을 막을 수 있는 유용한 술식이다.

• Journal of Korean Neurosurgical Society
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• 제29권5호
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• pp.604-608
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• 2000

Objective : The purpose of this non randomized prospective study was to verify the effect of pain control in small doses of epidural morphine and bupivacaine through continuous infusion for 48 hours. Patients and Methods : Thirty-five patients who underwent spine surgery including laminectomy, fusion with fixation were assigned into two groups ; pain control group(n＝20) and control group(n＝15). Pain score was measured on a visual analogue scale(VAS). A continuous infusor was used to give morphine and bupivacaine continuously via indwelling epidural catheter which was placed before closure of muscles in pain control group. Results : Mean scores(VAS) of pain control group were between 1.3 and 2.1 from the 30 min to the 72 hour, but the lowest mean score in the control group was about 2.6 at the 72 hour. Although a number of extra-analgesics were used in control group, differences of mean scores were statistically significant till 24 hour in pain control group. The patients in pain control group was less painful than the patients in control group from 24 hour till 72 hour, but it was statistically insignificant. There were some side effects such as nausea/vomiting, pruritus, urinary retention which existed transiently, but there was no respiratory depression. Conclusion : It was concluded that the early postoperative pain can be easily and safely controlled with continuous infusion of epidural morphine and bupivacaine in small doses.

• Journal of Korean Neurosurgical Society
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• 제65권1호
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• pp.96-106
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• 2022

Objective : The most common complication of anterior cervical discectomy and fusion (ACDF) is cage subsidence and maintenance of disc height affects postoperative clinical outcomes. We considered cage subsidence as an inappropriate indicator for evaluating preservation of disc height. Thus, this study aimed to consider patients with complications such as reduced total disc height compared to that before surgery and evaluate the relevance of several factors before ACDF. Methods : We retrospectively reviewed the medical records of 40 patients who underwent stand-alone single-level ACDF using a polyetheretherketone (PEEK) cage at our institution between January 2012 and December 2018. Our study population comprised 19 male and 21 female patients aged 24-70 years. The minimum follow-up period was 1 year. Twenty-seven patients had preoperative bone mineral density (BMD) data on dual-energy X-ray absorptiometry. Clinical parameters included sex, age, body mass index, smoking history, and prior medical history. Radiologic parameters included the C2-7 cobb angle, segmental angle, sagittal vertical axis, disc height, and total intervertebral height (TIH) at the preoperative and postoperative periods. Cage decrement was defined as the reduction in TIH at the 6-month follow-up compared to preoperative TIH. To evaluate the bone quality, Hounsfield unit (HU) value was calculated in the axial and sagittal images of conventional computed tomography. Results : Lumbar BMD values and cervical HU values were significantly correlated (r=0.733, p<0.001). We divided the patients into two groups based on cage decrement, and 47.5% of the total patients were regarded as cage decrement. There were statistically significant differences in the parameters of measuring the HU value of the vertebra and intraoperative distraction between the two groups. Using these identified factors, we performed a receiver operating characteristic (ROC) curve analysis. Based on the ROC curve, the cut-off point was 530 at the HU value of the upper cortical and cancellous vertebrae (p=0.014; area under the curve [AUC], 0.727; sensitivity, 94.7%; specificity, 42.9%) and 22.41 at intraoperative distraction (p=0.017; AUC, 0.722; sensitivity, 85.7%; specificity, 57.9%). Using this value, we converted these parameters into a bifurcated variable and assessed the multinomial regression analysis to evaluate the risk factors for cage decrement in ACDF. Intraoperative distraction and HU value of the upper vertebral body were independent factors of postoperative subsidence. Conclusion : Insufficient intraoperative distraction and low HU value showed a strong relationship with postoperative intervertebral height reduction following single stand-alone PEEK cage ACDF.

• Journal of Korean Neurosurgical Society
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• 제47권4호
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• pp.265-270
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• 2010

Objective : The purpose of this study is to identify the relationship between asymptomatic urinary tract infection (aUTI) and postoperative spine infection. Methods : A retrospective review was done in 355 women more than 65 years old who had undergone laminectomy and/or discectomy, and spinal fusion, between January 2004 and December 2008. Previously postulated risk factors (i.e., instrumentation, diabetes, prior corticosteroid therapy, previous spinal surgery, and smoking) were investigated. Furthermore, we added aUTI that was not previously considered. Results : Among 355 patients, 42 met the criteria for aUTI (Bacteriuria ${\geq}\;10^5\;CFU/mL$ and no associated symptoms). A postoperative spine infection was evident in 15 of 355 patients. Of the previously described risk factors, multi-levels (p<0.05), instrumentation (p<0.05) and diabetes (p<0.05) were proven risk factors, whereas aUTI (p>0.05) was not statistically significant. However, aUTI with Foley catheterization was statistically significant when Foley catheterization was added as a variable to the all existing risk factors. Conclusion : aUTI is not rare in elderly women admitted to the hospital for lumbar spine surgery. The results of this study suggest that aUTI with Foley catheterization may be considered a risk factor for postoperative spine infection in elderly women. Therefore, we would consider treating aUTI before operating on elderly women who will need Foley catheterization.

• 대한족부족관절학회지
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• 제1권2호
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• pp.119-125
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• 1997

The fracture and fracture-dislocation of the neck of the talus (Hawkins' type I-IV) are uncommon injuries and represent only 0.12 to 0.32% of all fracures. Authors clinically evaluated in 12 cases Whom treated fracures of the neck of the talus, at department of orthopaedic surgery, Sun General Hospital, from 1990 to 1996, and the following results are obtained. 1. Of 12 cases, there were 11 males and 1 female, average age was 30 years. 2. Causes of fracture was fall down injury in 7 cases(58%), traffic accident in 4 cases(33%), direct trauma in 1 case(8%). 3. According to the classification by Hawkins' type I in 2 cases(17%), type II in 7cases (58%), type III in 3cases(25%). 4. Associated injuries were calcaneal fracture in 3 cases, fracture-dislocation of talus in 3 cases, subtalar dislocation in 3 cases, medial malleolar fracture in 5 cases, soft tissue injury in 3 cases, femur and tibia fracture in 1 case, and lumbar Spine compression fracture in 1 case. 5. Average time to operation after injury was 2.5 days. 6. In 2 cases were treated conservatively and 10 cases were treated open reduction and internal fixation with screw or K-wire. 7. Complications were avascular necrosis in 4 cases, post traumatic arthritis in 2 cases, skin necrosis in 4 cases, and then ankle fusion was done in 2 cases. 8. High rate of complication was seen in the talar neck fracture associated with calcaneal fracture. In the analysis of above results, evaluated by Hawkins' scoring system were excellent to fair in 75%.

• Journal of Korean Neurosurgical Society
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• 제47권2호
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• pp.95-101
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• 2010

Objective : Clinical, radiographic, and outcomes assessments, focusing on complications, were performed in patients who underwent pedicle subtraction osteotomy (PSO) to assess correction effectiveness, fusion stability, procedural safety, neurological outcomes, complication rates, and overall patient outcomes. Methods : We analyzed data obtained from 13 consecutive PSO-treated patients presenting with fixed sagittal imbalances from 1999 to 2006. A single spine surgeon performed all operations. The median follow-up period was 73 months (range 41-114 months). Events during peri operative course and complications were closely monitored and carefully reviewed. Radiographs were obtained and measurements were done before surgery, immediately after surgery, and at the most recent follow-up examinations. Clinical outcomes were assessed using the Oswestry Disability Index and subjective satisfaction evaluation. Results : Following surgery, lumbar lordosis increased from $-14.1^{\circ}{\pm}20.5^{\circ}$ to $-46.3^{\circ}{\pm}12.8^{\circ}$ (p<0.0001). and the C7 plumb line improved from $115{\pm}43\;mm$ to $32{\pm}38\;mm$ (p<0.0001). There were 16 surgery-related complications in 8 patients; 3 intraoperative, 3 perioperative, and 10 late-onset postoperative. The prevalence of proximal junctional kyphosis (PJK) was 23% (3 of 13 patients). However, clinical outcomes were not adversely affected by PJK. Intraoperative blood loss averaged 2,984 mL. The C7 plumb line values and postoperative complications were closely correlated with clinical results. Conclusion : Intraoperative or postoperative complications are relatively common following PSO. Most late-onset complications in PSO patients were related to PJK and instrumentation failure. Correcting the C7 plumb line value with minimal operative complications seemed to lead to better clinical results.

• 대한골관절종양학회지
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• 제4권1호
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• pp.37-43
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• 1998

Between 1992 and 1996, 5 patients with the giant-cell tumor of the spine were treated. Four were female and one was male. The mean age was 34 years old, and the mean follow-up time was 36 months. The locations of the lesions were the cervical spine in 1, the thoracic spine in 3, and the lumbar spine in 1. Pain was the predominant presenting symptom in all cases and four had a neurological deficit. A combined anterior and posterior surgical approach wds as performed in all cases, which were also treated with AIF(anterior interbody fusion) and anterior and/or posterior instrumentation. Adjuvant radiation therapy was performed in 1 case of cervical spine. At the final follow-up, the pain and neurologic symptoms were improved. Radiologic examination showed no evidence of local recurrence and no failure of instrumentation of the spine.

• Neurospine
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• 제15권4호
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• pp.348-352
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• 2018

Objective: Postoperative dynamic cryo-compression (DC) therapy has been proposed as a method of reducing pain and the inflammatory response in the early postoperative period after orthopedic joint reconstruction surgery. Our aim was to analyze the analgesic efficacy of DC therapy after adult lumbar spinal surgery. Methods: DC was applied for 30 minutes every 6 hours after surgery. Pain was measured by a visual analogue scale (VAS) in the preoperative period, immediately after surgery, and every 6 hours postoperatively for the first 72 hours of the hospital stay. Patients' pain medication requirements were monitored using the patient-controlled analgesia system and patient charts. Twenty patients who received DC therapy were compared to 20 historical controls who were matched for demographic and surgical variables. Results: In the postanesthesia care unit, the mean VAS back pain score was $5.87{\pm}0.9$ in the DC group and $6.95{\pm}1.0$ (p=0.001) in the control group. The corresponding mean VAS scores for the DC vs. control groups were $3.8{\pm}1.1$ vs. $5.4{\pm}0.7$ (p < 0.001) at 6 hours postoperatively, and $2.7{\pm}0.7$ vs. $6.25{\pm}0.9$ (p<0.001) at discharge, respectively. The cumulative mean analgesic consumption of paracetamol, tenoxicam, and tramadol in the DC group vs. control group was $3,733.3{\pm}562.7mg$ vs. $4,633.3{\pm}693.5mg$ (p<0.005), $53.3{\pm}19.5mg$ vs. $85.3{\pm}33.4mg$ (p<0.005), and $63.3{\pm}83.4mg$ vs. $393.3{\pm}79.9mg$ (p<0.0001), respectively. Conclusion: The results of this study demonstrated a positive association between the use of DC therapy and accelerated improvement in patients during early rehabilitation after adult spine surgery compared to patients who were treated with painkillers only.