The Effect of Repetitive Insertion and Pullout of Spinal Screws on Pullout Resistance : A Biomechanical Study

백광흠,김광진,김재민,김충현,Bak, Koang Hum,Ferrara, Lisa,Kim, Kwang Jin,Kim, Jae Min,Kim, Choong Hyun,Benzel, Edward C. The Korean Neurosurgical Society 2001 Journal of Korean neurosurgical society Vol.30 No.2

목적 : 최근 척추 수술에 나사못을 사용하는 빈도와 범위가 넓어 지고 있는데 때로 수술 중 한번 삽입하였던 나사못을 다시 사용하는 경우가 있다. 인체 골과 타이타늄의 탄성계수가 크게 차이 나지만 반복 삽입 과정에서 나사못의 이가 손상될 가능성이 있다. 저자들은 나사못의 반복 삽입이 나사못의 인출 저항에 미치는 영향을 조사하였다. 방법 : 각각 6개의 세가지 다른 종류 cortical lateral mass screw, cancellous lateral mass screw and cervical vertebral body screw의 나사못을 시험하였다. 나사못을 인체의 골과 비슷한 밀도의 인공합성골에 삽입하였으며 삽입 중 삽입력을 측정하였고 그 후 Instron(Model TT-D, Canton, MA)을 이용하여 2.4mm의 속도로 인출하여 인장항력을 digital oscilloscope에 기록하였다. 위의 과정을 3회 반복하여 기록한 뒤 나사못을 광학 현미경으로 확대하여 관찰하였다. 결과 : cortical lateral mass screws의 평균 인장항력(1회인장 시험 $185.66N{\pm}42.60$, 2회 인장시험 $167.10N{\pm}27.01$, 3회인장 시험 $162.52N{\pm}23.83$ : p=0.03)과 cervical vertebral body screws ($386.0N{\pm}24.1$, $360.2N{\pm}17.5$ and $330.9N{\pm}16.7$ : p=0.0024)은 반복하여 삽입, 인장 검사 할 때 마다 감소하였으나 cancellous lateral mass screws의 평균 인장항력($194.00N{\pm}36.47$, $219.24N{\pm}26.58$ and $199.49N{\pm}36.63$ : p=0.24)은 감소하지 않았다. 전자현미경 소견에서 나사이의 끝이 무디어지고 표면이 문드러진 것을 관찰할 수 있었다. 결론 : 일부 나사못을 반복하여 삽입한 후 나사못의 인장항력이 감소되었으므로 수술중 여러번 삽입하였던 나사못은 최종 구조물에 사용되지 않아야 한다. Object : The clinical uses of screws are increasing with broader applications in spinal disorders. When screws are inserted repeatedly to achieve optimal position, tips of screw pitch may become damaged during insertion even though there are significant differences in the moduli of elasticity between bone and titanium. The effect of repeated screw insertion on pullout resistance was investigated. Methods : Three different titanium screws(cortical lateral mass screw, cancellous lateral mass screw and cervical vertebral body screw) were inserted into the synthetic cancellous material and then extracted axially at a rate of 2.4mm/min using Instron(Model TT-D, Canton, MA). Each set of screws was inserted and pulled out three times. There were six screws in each group. The insertional torque was measured with a torque wrench during insertion. Pullout strength was recorded with a digital oscilloscope. Results : The mean pullout force measurements for the cortical lateral mass screws($185.66N{\pm}42.60$, $167.10N{\pm}27.01$ and $162.52 N{\pm}23.83$ for first, second and third pullout respectively : p=0.03) and the cervical vertebral body screws($386.0N{\pm}24.1$, $360.2N{\pm}17.5$ and $330.9N{\pm}16.7$ : p=0.0024) showed consecutive decrease in pullout resistance after each pullout, whereas the cancellous lateral mass screws did not($194.00N{\pm}36.47$, $219.24N{\pm}26.58$ and 199.49N(36.63 : p=0.24). The SEM after insertion and pullout three times showed a blunting in the tip of the screw pitch and a smearing of the screw surface. Conclusions : Repetitive screw insertion and pullout resulted in the decrease of pullout resistance in certain screws possibly caused by blunting the screw tip. This means screw tips suffer deformations during either repeated insertion or pullout. Thus, the screws that have been inserted should not be used for the final construct.

요추간반 탈출증에 있어 MED(Microendoscopic Discectomy) System을 이용한 수술의 효율성과 수기

홍현종,오성훈,백광흠,김재민,김충현,김영수,고용,오석전,김광명,이상구,김남규,Hong, Hyun Jong,Oh, Seong Hoon,Bak, Kwang Hum,Kim, Jae Min,Kim, Choong Hyun,Kim, Young Soo,Ko, Yong,Oh, Suck Jun,Kim, Kwang Myung,Lee, Sang Gu,Kim, Nam Kyu 대한신경외과학회 2000 Journal of Korean neurosurgical society Vol.29 No.1

Objective : Percutaneous lumbar approaches such as arthroscopic discectomy, laser discectomy, and nucleotome remain controversial and have technical limitations to free fragment disc, bony pathology and access to L5-S1, The purpose of this study was to determine efficacy of this new endoscopic system and to report techniques and tactics. Methods : From July 1997 to May 1998, we treated 40 consecutive patients(43 levels) with the MED system. Mean age was 32 years(range ; 18 to 62). There were 30 males and 10 females. All patients had sciatica with SLRT limitation. There were 23 patients with disc herniation at L4-5 and 14 patients at L5-S1. Three patients had 2 level disc herniations. There was one far lateral disc herniation at L4-5. Results : Using modified MacNab criteria, there were 37 excellent results and 3 good result. Most patients were discharged within 3-4 days except 2 patients with dural tearing. There were no other complications. Mean operation time was 1.5 hours(range : 40 minutes to 2.5 hours). Conclusion : The MED system is a reliable approach to lumbar disc herniations. This system combines the advantages of conventional open surgery and a minimally invasive technique. As tactics for the doctors who wish to attempt, "palpate" the lamina by first dilator, identification of interlaminar space by removal of overlying soft tissue and confirmation of the shoulder portion of nerve root before discectomy are important to this procedure. We conclude that lumbar disc herniations can be successfully treated with MED approach.

두개강내 원발성 간엽성 종양에 대한 임상 고찰

이형중,김충현,백광흠,김영수,김재민,고용,오석전,김광명,Yi, Hyeong Joong,Kim, Choong Hyun,Bak, Koang Hum,Kim, Young Soo,Kim, Jae Min,Ko, Yong,Oh, Suck Jun,Kim, Kwang Myung 대한신경외과학회 2000 Journal of Korean neurosurgical society Vol.29 No.1

Objective : A few anecdotal cases of mesenchyme-derived tumors which grow into a cranial cavity have been reported that disclosed a dismal prognosis, due to their critical location, aggressive biological behavior, and high rate of surgical morbidity. The aim of this study is to search clinical factors related to these tumors. Methods : Eight patients who underwent surgical removal of intracranial mesenchymal tumors between January 1993 and December 1997 were studied retrospectively. The tumors included are three chordomas, two chondrosarcomas, two rhabdomyosarcomas, and one hemangiopericytoma. Authors compared clinical features, treatment, and results of our cases with reported cases. The mean follow-up period was 20.5 months. Results : All cases showed nonspecific, location-related clinical findings and arose from sphenopetroclival region. Single stage operation was performed in 4 cases, and skull base approaches in 3 cases. Adjuvant therapies were done in 2 cases. Recurrence was seen in 3 cases(37.5%), and 3 patients died. Interdisciplinary approach with otologic surgeon was done in 2 cases. Conclusion : Recent advancement of refined tactics has made these tumors amenable and provides prolongation of progression-free survival. These are modified skull base approaches, multi-modality treatment options, and inter-disciplinary team approaches. Good results may be expected for these mesenchymal tumors by aggressive resection and adjuvant therapies according to their biological nature.

뇌 동맥류 수술 후 혈관조영술의 적응증에 대한 분석

이우택,김재민,정진환,백광흠,김충현,김광명,오석전,Rhee, Woo Tack,Kim, Jae Min,Cheong, Jin Hwan,Bak, Koang Hum,Kim, Choong Hyun,Kim, Kwang Myung,Oh, Suck Jun 대한신경외과학회 2001 Journal of Korean neurosurgical society Vol.30 No.6

Objective : Subarachnoid hemorrhage(SAH) is still one of the most serious disease with high morbidity and mortality in the neurosurgical field. Clipping of the aneurysmal neck is the gold standard of the surgical treatment of aneurysmal SAH. The purpose of this study was to investigate the role of the postoperative angiography and to assess the risk factors related to the incomplete clipping. Materials and Methods : From July 1995 to June 1998, the pre- and postoperative angiography were performed in 50 patients among total 81 patients who have underwent the aneurysmal surgery. We reviewed the various contributing factors including age, sex, Hunt-Hess grade, Fisher grade and the premature rupture of aneurysm during operation retrospectively. Careful evaluation of pre- and postoperative angiography focusing on the size, shape, and remnant neck of the aneurysms and vasospasm was performed. According to the angiographic findings, the patients were divided into two groups ; a complete clipping group and an incomplete clipping group. The data were analyzed by using unpaired independent sample t test after F-test to compare the significance between two groups. Results : Incomplete clipping of aneurysms was found in 6(12%) patients through the evaluation of postoperative angiography. Among them, three cases were located on the middle cerebral artery territory. Whereas the patient age, sex, Hunt-Hess grade, and Fisher grade were not significant(p>0.05), an intraoperative premature rupture had a statistical significance(p<0.05). A severe vasospasm occurred in 24(48%) cases and one patient with anterior communicating aneurysm was reoperated due to residual sac. Conclusion : According to our experience, the surgeons' judgement is the most reliable factor in deciding the postoperative angiography. During the aneurysmal surgery, the premature rupture always disturbs a complete clipping of aneurysms. Therefore, the temporary clipping of parent arteries is considered essential for a successful clipping. We believe that the postoperative angiography has a role in decreasing the re-bleeding risk due to clip migration and an inaccurate clipping only in the selected cases.

두개강내 역형성 성상세포종의 신경교육종으로 전환 -증례보고-

오윤식 ( Yoon Sik Oh ),김충현 ( Choong Hyun Kim ),백광흠 ( Kwang Hum Bak ),김재민 ( Jae Min Kim ) 대한뇌종양학회·대한신경종양학회·대한소아뇌종양학회 2007 대한뇌종양학회지 Vol.6 No.2

Gliosarcoma is a rare biphasic central nervous system malignancy that are composed of distinct sarcomatous and glial neoplastic proportion. We report a rare case with transformation of recurrent anaplastic astrocytoma into gliosarcoma. A 26-year-old male patient presented with headache. He was diagnosed as neurofibromatosis type I, 5 years ago. Magnetic resonance image(MRI) showed a well-demarcated, heterogeneously enhancing space-occupying lesion in the right frontal lobe. He underwent an osteoplastic craniotomy with radical tumor resection. Histopathology of tumor showed heterogeneous pleomorphic nuclear hyperchromatism corresponding with anaplastic astrocytoma. He was taken radiotherapy and chemotherapy. Subsequent follow-up period of 11 months was uneventful until he developed a generalized tonic clonic seizure, along progressively worsening headache. MRI showed tumor recurrence in the right frontal lobe. Re-exploration was carried out and gross total resection was done. Pathological examination displayed a biphasic pattern of glial and sarcomatous component suggesting gliosarcoma. This is an uncommon case with transformation of anaplastic astrocytoma into gliosarcoma, and we discussed with pertinent literatures.

경막하 수낭종에 대한 임상적 고찰

백광흠,오석전,김광명,김남규,정환영 대한신경외과학회 1990 Journal of Korean neurosurgical society Vol.19 No.4

The author analysed 140 cases of subdural hygroma developed after head injury and various neurosurgical operations and was treated at Hanyang university hospital form 1983 to 1989. The results were analysed and summarized as follows. 1) The peak incidence was the age over 50 and under 10. 2) 104 cases (74.4%) were bilateral frontotemporoparietal lesions. 3) Causes were head injury (121 cases), operation for intracranial aneurysms (5 cases), ventriculoperitoneal shunt (5 cases), traumatic intracranial hematoma removal (4 cases), transcallosal tumor removal (2 cases), meningitis (2 cases), external ventricular drainage (1 cases). 4) Change in mental status without focal sign of brain damage was presenting symptom. 5) Operation was underwent if 63 cases and the reaccumulation rate was high (26.8%) after traphination but outcome was favourable. 6) Mortal rate in traumatic subdural hygroma was low (5.8%) because brain CT could detect subdural hygroma easily in early stage.

추궁절제수술후에 발생한 의인성 가성수막척수류 : 증례보고 Report of Cases

백광흠,김용석,김재민,고용,오성훈,오석전,김남규,김광명,박동우 대한신경외과학회 1996 Journal of Korean neurosurgical society Vol.25 No.10

Two unique cases of delayed nerve root herniation and entrapment into the pseudomeningocele through an unrepaired dural laceration at lumbar laminectomy were reported. Both patients presented with recurred radiculopathy. 3 and 6 years after first operation respectively. Lumbar myelography showed an extradural pseudomeningocele pouch in case 1 while showing no abnormality in case 2. Lumbar MRI in case 1 showed tangled herniated nerve root in the pouch of pseudomeningocele. Lumbar myelographic CT of case 2 showed delayed partial filling of the pseudomeningocele pouch only.

지주막하출혈로 인한 동안신경 마비에 대한 임상적 고찰

백광흠,오석준 한양대학교 의과대학 1993 한양의대 학술지 Vol.13 No.1

84 cases of internal carotid-posterior communicating artery (P-com) aneurysm out of 81 patients operated at the Hanyang university hospital were analysed to study the incidence, casung factors and prognosis of oculomotor nerve palsy due to P-com aneurysm. The result were summarized as follows. 1) Oculomotor nerve palsy occurred in 26 cases (31.0%) : total palsy in 18 cases (73.1%), partial palsy in 7 cases (28.9%) 2)The incidence of oculomotor nerve palsy seemed higher in aneurysms which was large, lobulated and especially in posterolateral inferior direction. But there was no relationship between amount of subarachnoid hemorrhage and oculomotor nerve palsy development. 3)15 cases (57.7%) of oculomotor nerve palsy recovered competely and 7 cases (26.9%) recovered partially and 4 cases (15.3%) showed no improvement at all. 4)The important prognostic factors in recovery were preoperative severity of oculomotor nerve palsy and timing of oculomotor nerve palsy development. The recovery rate improved by early aneurysm operation.

최소 침습 전방 경유 요추부 추체간 골유합술

백광흠,김영수,김재민,김충현,고용,오성훈,오석전,김광명,김남규 대한신경외과학회 1998 Journal of Korean neurosurgical society Vol.27 No.6

극외측 추간판 탈출증에 대한 복합 접근 수술법

백광흠,신형식,김재민,오성훈,김광명 대한신경외과학회 1996 Journal of Korean neurosurgical society Vol.25 No.2

A technique combining usual interlaminar approach and paraspinal intertransverse approach for exposing far-lateral disc herniations without disrupting the facet is described. This approach is useful because disc fragments can be removed from both intraspinal and paraspinal route with easy retraction and under short skin incision. This approach prevents reherniation by complete removing of residual nucleus pulposus. At the end of procedure the foramen can be explored in order to verify that foramen is opened. This approach is useful especially in operating the double herniations and extruded far lateral disc herniations.