Endovascular Treatment for a Penetrating Vertebral Artery Injury: Case Report

지규열,안정용,송우식,이병희 대한신경외과학회 2002 Journal of Korean neurosurgical society Vol.32 No.6

Efficacy of Percutaneous Epidural Neuroplasty Does Not Correlate with Dural Sac Cross-Sectional Area in Single Level Disc Disease

지규열,신동아,오창현,문봉주,최승현,윤영설,김긍년 연세대학교의과대학 2015 Yonsei medical journal Vol.56 No.3

Purpose: Percutaneous epidural neuroplasty (PEN) is a minimally invasive treatment. The efficacy of PEN has been relatively well investigated; however, the relationshipbetween the clinical effectiveness of PEN and the severity of spinal canal stenosis by disc material has not yet been established. The purpose of this study was to compare clinical outcomes of PEN according to the dural sac cross-sectionalarea in single level disc disease. Materials and Methods: This study included 363 patients with back pain from single level disc disease with and without radiculopathy. Patients were categorized into groups according to spinal canal compromiseby disc material: Category 1, less or more than 50%; and Category 2, three subgroups with lesser than a third, between a third and two thirds, and more than two thirds. Clinical outcomes were assessed according to the Visual Analog Scale (VAS) score for back pain and leg pain and Odom’s criteria at 1, 3, 6, 12, and 24 months after treatment. Results: The demographic data showed no difference betweengroups according to spinal canal compromise by disc material except age (older age correlated with more spinal canal compromise). The dural sac cross-sectional area did not correlate with the VAS scores for back and leg pain after PEN in single level disc disease in Groups 1 and 2. Odom’s criteria after PEN were also not different according to dural sac cross-sectional area by disc material. Conclusion: PEN is an effective procedure in treating single level lumbar disc herniationwithout affecting dural sac cross-sectional area.

Feasibility of Translaminar Screw Placement in Korean Population: Morphometric Analysis of Cervical Spine

지규열,신동아,오창현,박상혁,Ferry Kurniawan,이준호,전재균,김긍년 연세대학교의과대학 2015 Yonsei medical journal Vol.56 No.1

Purpose: To analyze the feasibility of unilateral and bilateral translaminar screw placement in Koran population, and compare the acceptance rate using previously reported data in American population. Materials and Methods: The translaminar lengths, thickness, heights, and sagittal-diagonal measurements were performed. The feasibility analysis was performed using unilateral and bilateral 3.5 mm cervicalscrew placement on the CT scans within 0.5 mm of safety margin. We also performed radiographic analysis of the morphometric dimensions and the feasibilityof unilateral and bilateral translaminar screw placement at C3‒C7. Results: Korean population had similar or significantly shorter translaminar lengths and thickness (lengths and thickness in C7 among males; lengths in C6‒C7 and thicknessin C4 among females) than American population, but had similar or significantlylonger translaminar heights and sagittal-diagonal measurements (heights in C3‒C7 and sagittal-diagonal measurements in C3‒C6 among males; heights in C7 and sagittal-diagonal measurements in C3‒C7 among females). Unilaterally, translaminarscrew acceptance rates in C3‒C7 were similar between Korean and Americanmale population, but the rates in C4‒C6 were significantly smaller between Korean and American female population. Bilaterally, translaminar screw acceptancerates in C3 and C5‒C6 were significantly larger between Korean and Americanmale population, but the rates in C3‒C7 were similar between Korean and American female population. Conclusion: The feasibility of unilateral and bilateraltranslaminar screw placement is different depending on different ethnics. Subaxialcervical unilateral translaminar screw placement among Korean male populationand bilateral placement at C4‒C7 among Korean female population are more acceptable than American population.

첩약 급여화보다 필수의료 투자가 먼저

지규열 대한의사협회 의료정책연구소 2020 의료정책포럼 Vol.18 No.2

Biomechanical Analysis of Biodegradable Cervical Plates Developed for Anterior Cervical Discectomy and Fusion

조평구,지규열,박상혁,신동아 대한척추외과학회 2018 Asian Spine Journal Vol.12 No.6

Study Design: In-vitro biomechanical investigation. Purpose: To evaluate the biomechanical effects of the degeneration of the biodegradable cervical plates developed for anterior cervical discectomy and fusion (ACDF) on fusion and adjacent levels. Overview of Literature: Biodegradable implants have been recently introduced for cervical spine surgery. However, their effectiveness and safety remains unclear. Methods: A linear three-dimensional finite element (FE) model of the lower cervical spine, comprising the C4–C6 vertebrae was developed using computed tomography images of a 46-year-old woman. The model was validated by comparison with previous reports. Four models of ACDF were analyzed and compared: (1) a titanium plate and bone block (Tita), (2) strong biodegradable plate and bone block (PLA-4G) that represents the early state of the biodegradable plate with full strength, (3) weak biodegradable plate and bone block (PLA-1G) that represents the late state of the biodegradable plate with decreased strength, and (4) stand-alone bone block (Bloc). FE analysis was performed to investigate the relative motion and intervertebral disc stress at the surgical (C5–C6 segment) and adjacent (C4–C5 segment) levels. Results: The Tita and PLA-4G models were superior to the other models in terms of higher segment stiffness, smaller relative motion, and lower bone stress at the surgical level. However, the maximal von Mises stress at the intervertebral disc at the adjacent level was significantly higher in the Tita and PLA-4G models than in the other models. The relative motion at the adjacent level was significantly lower in the PLA-1G and Bloc models than in the other models. Conclusions: The use of biodegradable plates will enhance spinal fusion in the initial stronger period and prevent adjacent segment degeneration in the later, weaker period.

딥러닝 기반 디자인 선호도 예측 및 추천시스템: 자동차 휠 설계 사례

이성희(Sunghee Lee),강남우(Namwoo Kang) 대한기계학회 2020 대한기계학회 춘추학술대회 Vol.2020 No.12

Slip Reduction Rate between Minimal Invasive and Conventional Unilateral Transforaminal Interbody Fusion in Patients with Low-Grade Isthmic Spondylolisthesis

오창현,지규열,전재균,이준호,윤승환,현동근 대한척추신경외과학회 2013 Neurospine Vol.10 No.4

Objective: To compare the slip reduction rate and clinical outcomes between unilateral conventional transforaminal lumbar interbody fusion (conventional TLIF) and unilateral minimal invasive TLIF (minimal TLIF) with pedicle screw fixation for treatment of one level low-grade symptomatic isthmic spondylolisthesis. Methods: Between February 2008 and April 2012, 25 patients with low-grade isthmic spondylolisthesis underwent conventional TLIF (12 patients) and minimal TLIF (13 patients) in single university hospital by a single surgeon. Lateral radiographs of lumbar spine were taken 12 months after surgery to analyze the degree of slip reduction and the clinical outcome. All measurements were performed by a single observer. Results: The demographic data between conventional TLIF and minimal TLIF were not different. Slip percentage was reduced from 15.00% to 8.33% in conventional TLIF, and from 14.15% to 9.62% in minimal TLIF. In both groups, slip percentage was significantly improved postoperatively (p=0.002), but no significant intergroup differences of slip percentage in preoperative and postoperative were found. The reduction rate also not different between conventional TLIF (45.41±28.80%) and minimal TLIF (32.91±32.12%, p=0.318). Conclusion: Conventional TLIF and minimal TLIF with pedicle screw fixation showed good slip reduction in patients with one level low-grade symptomatic isthmic spondylolisthesis. The slip percentage and reduction rate were similar in the conventional TLIF and minimal TLIF.

Repeated Complication Following Atlantoaxial Fusion: A Case Report

오창현,지규열,서현성,윤승환,현동근,박형천 대한척추신경외과학회 2014 Neurospine Vol.11 No.1

A patients with atlantoaixial instability and osodontoideum underwent atlantoaixial fusion (Harms and Melcher technique) with demineralized bone matrix. But, unfortunately, the both pedicle screws in C2 were fractured within 9 weeks follow-up periods after several suspected episode of neck hyper-flexion. Fractured screws were not contact to occipital bone in several imaging studies, but it could irritate the occipital bone when neck extension because the relatively close distance between the occipital bone and C1 posterior arch. The patient underwent revision operation with translaminar screw fixation with autologus iliac bone graft. Postsurgical course were uneventful except donor site pain, but the bony fusion was not satisfied after 4 months follow-up. The patient re-underwent revision operation in other hospital. Continuous complication after atlantoaixial fusion is rare, but the clinical course could be unlucky to patients. Postoperative immobilization could be important to prevent the unintended clinical course of patients.

Paralytic Ileus and Prophylactic Gastrointestinal Motility Medication after Spinal Operation

오창현,윤승환,지규열,현동근,박형천,김여주 연세대학교의과대학 2015 Yonsei medical journal Vol.56 No.6

Purpose: To investigate the prevalence of paralytic ileus after spinal operation in the supine or prone operative position and to determine the efficacy of prophylactic gastrointestinal motility medications in preventing symptomatic paralytic ileus after a spinaloperation. Materials and Methods: All patients received spinal surgery in the supine or prone operative position. The study period was dividedinto two phases: first, to analyze the prevalence of radiographic and symptomatic paralytic ileus after a spinal operation, and second, to determine the therapeutic effects of prophylactic gastrointestinal motility medications (postoperative intravenous injectionof scopolamine butylbromide and metoclopramide hydrochloride) on symptomatic paralytic ileus after a spinal operation. Results: Basic demographic data were not different. In the first phase of this study, 27 patients (32.9%) with radiographic paralytic ileus and 11 patients (13.4%) with symptomatic paralytic ileus were observed. Radiographic paralytic ileus was more often noted in patients who underwent an operation in the prone position (p=0.044); whereas the occurrence of symptomatic paralytic ileus was not different between the supine and prone positioned patients (p=0.385). In the second phase, prophylactic medications were shown to be ineffective in preventing symptomatic paralytic ileus after spinal surgery [symptomatic paralytic ileus was observedin 11.1% (4/36) with prophylactic medication and 16.7% (5/30) with a placebo, p=0.513]. Conclusion: Spinal surgery in the prone position was shown to increase the likelihood of radiographic paralytic ileus occurrence, but not symptomatic paralytic ileus. Unfortunately, the prophylactic medications to prevent symptomatic paralytic ileus after spine surgery were shown to be ineffective.

Surface Landmarks do not Correspond to Exact Levels of the Cervical Spine : References According to the Sex, Age and Height

Chang Hyun Oh,윤승환,지규열,현동근,Chun Gil Choi,임현경,A Reum Jang 대한척추신경외과학회 2014 Neurospine Vol.11 No.3

Objective: A general orientation along the cervical spine could be estimated by external landmarks, and it was useful, quick and less exposable to radiation, but, sometimes it gave reference confusion of target cervical level. The authors reviewed the corresponding between the neck external landmarks and cervical levels. Methods: Totally 1,031 cervical lateral radiographs of different patients were reviewed in single university hospital. Its compositions were 534 of males and 497 females; 86 of second decades (10-19 years-old), 169 of third decades, 159 of fourth decades, 209 of fifth decades, 275 of sixth decades, and 133 of more than seventh decades (>60 years-old). Reference external landmarks (mandible, hyoid bone, thyroid cartilage, and cricothyroid membrane) with compounding factors were reviewed. Results: The reference levels of cervical landmarks were C2.13 with mandible angle, C3.54 with hyoid bone, C5.12 with thyroid cartilage, and C6.01 with cricothyroid membrane. The reference levels of cervical landmarks were differently observed by sex, age, and somatometric measurement (height) accordingly mandible angle from C1 to C3, hyoid bone from disc level of C2 and C3 to C5, thyroid cartilage from disc level of C3 and C4 to C7, and cricothyroid membrane from C4 to disc level of C7 and T1. Conclusion: Surface landmarks only provide general reference points, but not correspond to exact levels of the cervical spine. Intraoperative fluoroscopy ensures a more precise placement to the targeted cervical level.