Efficacy of 3D-Printed Titanium Mesh-Type Patient-Specific Implant for Cranioplasty / 대한신경손상학회지

Objective@#Autologous bone grafting for cranioplasty is associated with a high infection rate and bone absorption. Synthetic implant materials for cranioplasty have been developed. In this study, we evaluated the efficacy of titanium mesh-type patient-specific implants (PSIs) for patients with skull defects using the dice similarity coefficient (DSC), clinical outcomes, and artifacts caused by implants. @*Methods@#This retrospective study included 40 patients who underwent cranioplasty with a titanium mesh PSI at our institution. Based on preoperative and postoperative computed tomography scans, we calculated DSC and artifacts. @*Results@#The calculated DSC of 40 patients was 0.75, and the noise was 13.89% higher in the region of interest (ROI) near the implanted side (average, 7.64 hounsfield unit [HU]±2.62) than in the normal bone (average, 6.72 HU±2.35). However, the image signal-to-noise ratio did not significantly differ between the ROI near the implanted side (4.77±1.78) and normal bone (4.97±1.88). The patients showed no significant perioperative complications that required a secondary operation. @*Conclusion@#Titanium mesh-type PSIs for cranioplasty have excellent DSC values with lower artifacts and complication rates.

Upper Cervical Subluxation and Cervicomedullary Junction Compression in Patients with Rheumatoid Arthritis

OBJECTIVE: Rheumatoid arthritis (RA) is known to involve the cervical spine up to 86%. It often causes cervical instability like atlantoaxial subluxation (AAS), subaxial subluxation, and vertical subluxation (VS). In order to find the relation between RA and cord compression, we will evaluate the characteristics and risk factors of basilar invagination (BI) and cervicomedullary junction (CMJ) compression.METHODS: From January 2007 to May 2015, 12667 patients administrated to Hanyang University Medical Center. Four thousand three hundred eighty-six patients took cervical X-ray and 250 patients took cervical computed tomography or magnetic resonance imaging. Radiologic parameters, medication records were obtained from 242 patients. Multivariate logistic regression analysis was performed with correlation of CMJ compression, basin-dental interval (BDI), basin-posterior axial line interval (BAI), pannus formation, BI, and AAS.RESULTS: In the point of CMJ compression, atlantodental interval (ADI), posterior-atlantodental interval, BAI, AAS, and BI are relatively highly correlated. Patients with BI have 82 times strong possibility of radiologic confirmed CMJ compression, while AAS has 6-fold and pannus formation has the 3-fold possibility. Compared to the low incidence of BI, AAS and pannus formation have more proportion in CMJ compression. Furthermore, wrist joint erosion was correlated with VS and AAS.CONCLUSION: BI has a very strong possibility of CMJ compression, while AAS and pannus formation have a high proportion in CMJ compression. Hence bilateral wrist joint erosion can be used as an indicator for the timing of screening test for cervical involvement. We suggest the early recommendation of cervical spine examination for the diagnosis of cervical involvement in order to prevent morbidity and mortality.

Risk Factors of Secondary Lumbar Discectomy of a Herniated Lumbar Disc after Lumbar Discectomy

OBJECTIVE: To study risk factors of secondary lumbar discectomy (LD) for recurrent herniated lumbar disc (HLD) and identify methods to lower the rate of recurrence.METHODS: Data from 160 patients who underwent primary LD were collected retrospectively. Demographic features, radiologic findings including Pfirrmann disc degeneration, and surgical information were analyzed to compare risks between revision and non-revision patients.RESULTS: The revision rate was 15% (24 patients), and the mean follow-up was 28.3 months. HLD recurrence was not related to any demographic characteristics. Primary and secondary LD were most common at the L4–5 level, but the level of operation was not significantly associated with revision. Primary LD most commonly had a Pfirrmann disc degeneration grade of 3, followed by 4. For recurrent HLD, Pfirrmann grade 4 was most common and was statistically significant (p<0.05). A body mass index (BMI) over 30 was considered obese and was significantly related with HLD revision (p<0.05).CONCLUSION: Patients with high BMI or severe disc degeneration should be informed of HLD revision.

Upper Cervical Subluxation and Cervicomedullary Junction Compression in Patients with Rheumatoid Arthritis

OBJECTIVE: Rheumatoid arthritis (RA) is known to involve the cervical spine up to 86%. It often causes cervical instability like atlantoaxial subluxation (AAS), subaxial subluxation, and vertical subluxation (VS). In order to find the relation between RA and cord compression, we will evaluate the characteristics and risk factors of basilar invagination (BI) and cervicomedullary junction (CMJ) compression. METHODS: From January 2007 to May 2015, 12667 patients administrated to Hanyang University Medical Center. Four thousand three hundred eighty-six patients took cervical X-ray and 250 patients took cervical computed tomography or magnetic resonance imaging. Radiologic parameters, medication records were obtained from 242 patients. Multivariate logistic regression analysis was performed with correlation of CMJ compression, basin-dental interval (BDI), basin-posterior axial line interval (BAI), pannus formation, BI, and AAS. RESULTS: In the point of CMJ compression, atlantodental interval (ADI), posterior-atlantodental interval, BAI, AAS, and BI are relatively highly correlated. Patients with BI have 82 times strong possibility of radiologic confirmed CMJ compression, while AAS has 6-fold and pannus formation has the 3-fold possibility. Compared to the low incidence of BI, AAS and pannus formation have more proportion in CMJ compression. Furthermore, wrist joint erosion was correlated with VS and AAS. CONCLUSION: BI has a very strong possibility of CMJ compression, while AAS and pannus formation have a high proportion in CMJ compression. Hence bilateral wrist joint erosion can be used as an indicator for the timing of screening test for cervical involvement. We suggest the early recommendation of cervical spine examination for the diagnosis of cervical involvement in order to prevent morbidity and mortality.

Risk Factors of Secondary Lumbar Discectomy of a Herniated Lumbar Disc after Lumbar Discectomy

OBJECTIVE: To study risk factors of secondary lumbar discectomy (LD) for recurrent herniated lumbar disc (HLD) and identify methods to lower the rate of recurrence. METHODS: Data from 160 patients who underwent primary LD were collected retrospectively. Demographic features, radiologic findings including Pfirrmann disc degeneration, and surgical information were analyzed to compare risks between revision and non-revision patients. RESULTS: The revision rate was 15% (24 patients), and the mean follow-up was 28.3 months. HLD recurrence was not related to any demographic characteristics. Primary and secondary LD were most common at the L4–5 level, but the level of operation was not significantly associated with revision. Primary LD most commonly had a Pfirrmann disc degeneration grade of 3, followed by 4. For recurrent HLD, Pfirrmann grade 4 was most common and was statistically significant (p<0.05). A body mass index (BMI) over 30 was considered obese and was significantly related with HLD revision (p<0.05). CONCLUSION: Patients with high BMI or severe disc degeneration should be informed of HLD revision.

Risk Factors of Delayed Surgical Intervention after Conservatively Treated Acute Traumatic Subdural Hematoma

OBJECTIVE: Acute subdural hematoma (ASDH) is generally considered a condition that should be managed surgically. However, some patients initially receive conservative treatment, a subset of whom require surgical intervention later. This study aimed to evaluate the predictors of delayed surgical intervention in ASDH patients who are initially managed conservatively. METHODS: From January 2007 to December 2015, 842 patients diagnosed with ASDH were treated at our institution. Among them, 158 patients with convexity ASDH were initially treated conservatively. Patients were divided into a delayed surgery group and a conservative group. Demographic characteristics, past medication and medical histories, and radiological and laboratory data were collected by retrospective chart review. Independent risk factors were identified with univariate and multivariate analyses. RESULTS: Twenty-eight patients (17.7%) underwent delayed surgical intervention. Their mean age was 69.0 years, and 82.1% were male. Hypertension, diabetes mellitus, and heart disease prevalence and use of anti-platelet agents did not significantly differ from the conservative group. However, age (p=0.024), previous cerebral infarction history (p=0.026), increased maximal hematoma thickness (p<0.001), midline shifting (p=0.001) and accompanying subarachnoid hemorrhage (p=0.022) on initial brain computed tomography (CT) scan, low hemoglobin level (p<0.001), high leukocyte count (p=0.004), and low glucose level (p=0.002) were significantly associated with delayed surgical intervention. In multivariate analysis, increased maximal hematoma thickness (odds ratio [OR]=1.279, 95% confidence interval [CI] 1.075–1.521; p=0.006), low hemoglobin level (OR=0.673, 95% CI 0.467–0.970; p=0.034), and high leukocyte count (OR=1.142, 95% CI 1.024–1.272; p=0.017) were independent risk factors for delayed surgical intervention. CONCLUSION: Due to the high likelihood of delayed surgical intervention among minimal ASDH patients with a thicker hematoma on initial brain CT, lower hemoglobin level, and higher leukocyte count, these patients should receive more careful observation.

Effect of Using Local Intrawound Vancomycin Powder in Addition to Intravenous Antibiotics in Posterior Lumbar Surgery: Midterm Result in a Single-Center Study

OBJECTIVE: We conducted this study to report the efficacy of local application of vancomycin powder in the setting of surgical site infection (SSI) of posterior lumbar surgical procedures and to figure out risk factors of SSIs. METHODS: From February 2013 to December 2013, SSI rates following 275 posterior lumbar surgeries of which intrawound vancomycin powder was used in combination with intravenous antibiotics (Vanco group) were assessed. Compared with 296 posterior lumbar procedures with intravenous antibiotic only group from February 2012 to December 2012 (non-Vanco group), various infection rates were assessed. Univariate and multivariate analysis to figure out risk factors of infection among Vanco group were done. RESULTS: Statistically significant reduction of SSI in Vanco group (5.5%) from non-Vanco group (10.5%) was confirmed (p=0.028). Mean follow-up period was 8 months. Rate of acute staphylococcal SSIs reduced statistically significantly to 4% compared to 7.4% of non-Vanco group (p=0.041). Deep staphylococcal infection decreased to 2 compared to 8 and deep methicillin-resistant Staphylococcus aureus infection also decreased to 1 compared to 5 in non-Vanco group. No systemic complication was observed. Statistically significant risk factors associated with SSI were diabetes mellitus, history of cardiovascular disease, length of hospital stay, number of instrumented level and history of previous surgery. CONCLUSION: In this series of 571 patients, intrawound vancomycin powder usage resulted in significant decrease in SSI rates in our posterior lumbar surgical procedures. Patients at high risk of infection are highly recommended as a candidate for this technique.

Comparison of Endovascular Treatments of Ruptured Dissecting Aneurysms of the Intracranial Internal Carotid Artery and Vertebral Artery with a Review of the Literature

OBJECTIVE: Subarachnoid hemorrhage (SAH) caused by rupture of an internal carotid artery (ICA) or vertebral artery (VA) dissecting aneuryesm is rare. Various treatment strategies have been used for ruptured intracranial dissections. The purpose of this study is to compare the clinical and angiographic characteristics and outcomes of endovascular treatment for ruptured dissecting aneurysms of the intracranial ICA and VA. METHODS: The authors retrospectively reviewed a series of patients with SAH caused by ruptured intracranial ICA and VA dissecting aneurysms from March 2009 to April 2014. The relevant demographic and angiographic data were collected, categorized and analyzed with respect to the outcome. RESULTS: Fifteen patients were identified (6 ICAs and 9 VAs). The percentage of patients showing unfavorable initial clinical condition and a history of hypertension was higher in the VA group. The initial aneurysm detection rate and the percentage of fusiform aneurysms were higher in the VA group. In the ICA group, all patients were treated with double stent-assisted coiling, and showed favorable outcomes. In the VA group, 2 patients were treated with double stent-assisted coiling and 7 with endovascular trapping. Two patients died and 1 patient developed severe disability. CONCLUSION: Clinically, grave initial clinical condition and hypertension were more frequent in the VA group. Angiographically, bleb-like aneurysms were more frequent in the ICA group and fusiform aneurysms were more frequent in the VA group. Endovascular treatment of these aneurysms is feasible and the result is acceptable in most instances.

Risk Factors for the Development and Progression of Atlantoaxial Subluxation in Surgically Treated Rheumatoid Arthritis Patients, Considering the Time Interval between Rheumatoid Arthritis Diagnosis and Surgery

OBJECTIVE: Rheumatoid arthritis (RA) is a systemic disease that can affect the cervical spine, especially the atlantoaxial region. The present study evaluated the risk factors for atlantoaxial subluxation (AAS) development and progression in patients who have undergone surgical treatment. METHODS: We retrospectively analyzed the data of 62 patients with RA and surgically treated AAS between 2002 and 2015. Additionally, we identified 62 patients as controls using propensity score matching of sex and age among 12667 RA patients from a rheumatology registry between 2007 and 2015. We extracted patient data, including sex, age at diagnosis, age at surgery, disease duration, radiographic hand joint changes, and history of methotrexate use, and laboratory data, including presence of rheumatoid factor and the C-reactive protein (CRP) level. RESULTS: The mean patient age at diagnosis was 38.0 years. The mean time interval between RA diagnosis and AAS surgery was 13.6±7.0 years. The risk factors for surgically treated AAS development were the serum CRP level (p=0.005) and radiographic hand joint erosion (p=0.009). The risk factors for AAS progression were a short time interval between RA diagnosis and radiographic hand joint erosion (p<0.001) and young age at RA diagnosis (p=0.04). CONCLUSION: The CRP level at RA diagnosis and a short time interval between RA diagnosis and radiographic hand joint erosion might be risk factors for surgically treated AAS development in RA patients. Additionally, a short time interval between RA diagnosis and radiographic hand joint erosion and young age at RA diagnosis might be risk factors for AAS progression.

Effects of a Temperature-Sensitive, Anti-Adhesive Agent on the Reduction of Adhesion in a Rabbit Laminectomy Model

OBJECTIVE: A common cause of failure in laminectomy surgery is when epidural, peridural, or perineural adhesion occurs postoperatively. The purpose of this study is to examine the efficacy of a temperature-sensitive, anti-adhesive agent (TSAA agent), Guardix-SG®, as a mechanical barrier for the prevention or reduction of peridural scar adhesion in a rabbit laminectomy model. METHODS: Twenty-six mature rabbits were used for this study. Each rabbit underwent two separate laminectomies at lumbar vertebrae L3 and L6, left empty (the control group) and applied 2 mL of the TSAA agent (the experimental group), respectively. Invasive scar formation or inflammation after laminectomy was quantitatively evaluated by measuring the thickness of the dura, the distance from the surface of dura to the scar tissues, the number of inflammatory cells in the scar tissues at the laminectomy site, and the concentration of collagen in histological sections. RESULTS: At 6 weeks postsurgery, the dura was significantly thinner and the distance from the surface of dura to the scar tissues was greater in the experimental group than in the control group (p=0.04 and p=0.01). The number of inflammatory cells was not significantly different in the two groups (p=0.08), although the mean number of inflammatory cells was relatively lower in the experimental group than in the control group. CONCLUSION: The current study suggests that the TSAA agent, Guardix-SG®, could be useful as an interpositional physical barrier after laminectomy for the prevention or reduction of adhesion.

Unilateral C1 Lateral Mass and C2 Pedicle Screw Fixation for Atlantoaxial Instability in Rheumatoid Arthritis Patients: Comparison with the Bilateral Method

OBJECTIVE: Bilateral C1 lateral mass and C2 pedicle screw fixation (C1LM-C2P) is an ideal technique for correcting atlantoaxial instability (AAI). However, the inevitable situation of vertebral artery injury or unfavorable bone structure may necessitate the use of unilateral C1LM-C2P. This study compares the fusion rates of the C1 lateral mass and C2 pedicle screw in the unilateral and bilateral methods. METHODS: Over five years, C1LM-C2P was performed in 25 patients with AAI in our institute. Preoperative studies including cervical X-ray, three-dimensional computed tomography (CT), CT angiogram, and magnetic resonance imaging were performed. To evaluate bony fusion, measurements of the atlanto-dental interval (ADI) and CT scans were performed in the preoperative period, immediate postoperative period, and postoperatively at 1, 3, 6, and 12 months. RESULTS: Unilateral C1LM-C2P was performed in 11 patients (44%). The need to perform unilateral C1LM-C2P was due to anomalous course of the vertebral artery in eight patients (73%) and severe degenerative arthritis in three patients (27%). The mean ADI in the bilateral group was 2.09 mm in the immediate postoperative period and 1.75 mm in 12-months postoperatively. The mean ADI in the unilateral group was 1.82 mm in the immediate postoperative period and 1.91 mm in 12-months postoperatively. Comparison of ADI measurements showed no significant differences in either group (p=0.893), and the fusion rate was 100% in both groups. CONCLUSION: Although bilateral C1LM-C2P is effective for AAI from a biomechanical perspective, unilateral screw fixation is a useful alternative in patients with anatomical variations.

Cerebral Infarction after Traumatic Brain Injury: Incidence and Risk Factors / 대한신경손상학회지

OBJECTIVE: Post-traumatic cerebral infarction (PTCI) is one of the most severe secondary insults after traumatic brain injury (TBI), and is known to be associated with poor outcome and high mortality rate. We assessed the practical incidence and risk factors for the development of PTCI. METHODS: We conducted retrospective study on 986 consecutive patients with TBI from the period May 2005 to November 2012 at our institution. The definition of PTCI was made on non-enhanced CT scan based on a well-demarcated or fairly discernible region of low attenuation following specific vascular territory with normal initial CT. Clinical and radiological findings that related to patients' outcome were reviewed and statistically compared. RESULTS: PTCI was observed in 21 (2.1%) patients. Of various parameters, age (p=0.037), initial Glasgow coma scale score (p<0.01), brain herniation (p=0.044), and decompressive craniectomy (p=0.012) were significantly higher in patients with PTCI than patients who do not have PTCI. Duration between accident and PTCI, patterns of TBI and vascular territory of PTCI were not specific. The mortality rates were significantly higher in patients with PTCI than without PTCI. CONCLUSION: The development of PTCI is rare after TBI, but it usually results in serious outcome and high mortality. Early recognition for risks and aggressive managements is mandatory to prevent PTCI.

The Predicting Factors for Recurrence of Chronic Subdural Hematoma Treated with Burr Hole and Drainage / 대한신경손상학회지

OBJECTIVE: Chronic subdural hematoma (CSDH) is common in elderly patients. So, with an increasing number of elderly people in the general population, there is a need to investigate risk factors which increase recurrence rate. In this study, factors affecting the postoperative recurrence are investigated based on the reoperative CSDH cases. METHODS: Total of ninety-seven patients was enrolled in this study who had have operation for CSDH. In all patients, one burr hole trephination and drainage was the method of choice for the initial treatment of CSDH. We retrospectively evaluated several factors which affect to recurrence of CSDH. RESULTS: Retrospective analysis was performed in 97 patients. Sixteen patients experienced reoperation within 3 months (16/97, 16.5%) for recurrence of CSDH. And, when hematoma was divided by internal architecture, heterogeneous density group seems to be have close relationship with recurrence more significantly than homogeneous density group (p=0.002). Hypertension, diabetes mellitus, early removal of drainage tube, bilaterality of hematoma also have significant relationship with recurrence. CONCLUSION: Recurrence rate of CSDH treated with one burr hole drainage is related with some various factors. There was statistically significant difference between recurred group and non-recurred group. Not only demographic factors but also internal architecture on preoperative brain computed tomography is a significant predicting factor of recurrence in CSDH patients who underwent a surgery. In this study, heterogeneous type hematoma have significantly related with recurrence of CSDH. We should give attention to these predicting factors for more effective care.

Comparison of Incidence and Risk Factors for Shunt-dependent Hydrocephalus in Aneurysmal Subarachnoid Hemorrhage Patients

OBJECTIVE: The objective of this study was to compare the incidence of ventricular shunt placement for shunt-dependent hydrocephalus (SDHC) after clipping versus coiling of ruptured aneurysms. MATERIALS AND METHODS: A retrospective review was conducted in 215 patients with aneurysmal subarachnoid hemorrhage (SAH) who underwent surgical clipping or endovascular coiling during the period from May 2008 to December 2011. Relevant clinical and radiographic data were analyzed with regard to the incidence of hydrocephalus and ventriculo-peritoneal shunt (VPS). Patients treated with clipping were assigned to Group A, while those treated with coiling were assigned to Group B. RESULTS: Of 215 patients (157 clipping, 58 coiling), no significant difference in the incidence of final VPS was observed between treatment modalities (15.3% vs. 10.3%) (p = 0.35). Independent risk factors for VPS for treatment of chronic hydrocephalus were as follows: (1) older than 65 years, (2) poorer Hunt-Hess grade IV and V, (3) Fisher grade III and IV, and (4) particularly initial presence of an intraventricular hemorrhage. CONCLUSION: In this study comparing two modalities for treatment of aneurysm, there was no difference in the incidence of chronic hydrocephalus requiring VPS. A significantly higher rate of shunt dependency was observed for age older than 65 years, poor initial neurological status, and thick SAH with presence of initial intraventricular hemorrhage. By understanding these factors related to development of SDHC and results, it is expected that management of aneurysmal SAH will result in a better prognosis.

Chronic Subdural Hematoma in Young Adult: An Age Comparison Study / 대한신경손상학회지

OBJECTIVE: Incidence of chronic subdural hematoma (CSDH) is gradually increasing in young adults for several reasons. In this study, we aimed to identify features of CSDH noted in young adults that distinguish the disease from CSDH diagnosed in the elderly. METHODS: One hundred eighty-two patients with CSDH who underwent a total of 218 surgical procedures between January 2003 and February 2010 were retrospectively reviewed with regard to clinical presentation, radiographic results and prognosis including recurrence. To compare younger patients with the elderly, patients were divided into three groups on the basis of age (Group A: or =65 years). RESULTS: Group A showed a male predominance (p=0.0001), lower rate of recurrence (p=0.0012), shorter symptom duration (p=0.035), and fewer leading signs such as hemispheric symptoms (p=0.005) compared to Groups B and C. Radiologic findings such as maximal hematoma thickness (p<0.0001) and degree of midline shift (p=0.028) were less severe in Group A than Groups B and C. Alcoholism was the most prevalent illness in all three groups. When exempting infants with hematologic malignancy, non-recurrence, previous trauma history, headache as leading symptom, and no mortality were all common in younger adults (all p<0.05). CONCLUSION: Young adults with CSDH show less severe clinical and radiologic features as well as fewer recurrences than noted in the elderly population. Even if a clinician's index of suspicion of CSDH in young adults complaining of headache is not high, meticulous radiologic surveillance could find CSDH, leading to satisfactory results including less frequent recurrence.

Perioperative Risk Factors Related to Lumbar Spine Fusion Surgery in Korean Geriatric Patients

OBJECTIVE: Life expectancy for humans has increased dramatically and with this there has been a considerable increase in the number of patients suffering from lumbar spine disease. Symptomatic lumbar spinal disease should be treated, even in the elderly, and surgical procedures such as fusion surgery are needed for moderate to severe lumbar spinal disease. However, various perioperative complications are associated with fusion surgery. The aim of this study was to examine perioperative complications and assess risk factors associated with lumbar spinal fusion, focusing on geriatric patients at least 70 years of age in the Republic of Korea. METHODS: We retrospectively investigated 489 patients with various lumbar spinal diseases who underwent lumbar spinal fusion surgery between 2003 and 2007 at our institution. Three fusion procedures and the number of fused segments were analyzed in this study. Chronic diseases were also evaluated. Risk factors for complications and their association with age were analyzed. RESULTS: In this study, 74 patients experienced complications (15%). The rate of perioperative complications was significantly higher in patients 70 years of age or older than in other age groups (univariate analysis, p=0.001; multivariate analysis, p=0.004). However, perioperative complications were not significantly associated with the other factors tested (sex, comorbidities, operation procedures, fusion segments involved). CONCLUSION: Increasing age was an important risk factor for perioperative complications in patients undergoing lumbar spinal fusion surgery whereas other factors were not significant. We recommend good clinical judgment and careful selection of geriatric patients undergoing lumbar spinal fusion surgery.

Long-Term Follow-Up Radiologic and Clinical Evaluation of Cylindrical Cage for Anterior Interbody Fusion in Degenerative Cervical Disc Disease

OBJECTIVE: Various procedures have been introduced for anterior interbody fusion in degenerative cervical disc disease including plate systems with autologous iliac bone, carbon cages, and cylindrical cages. However, except for plate systems, the long-term results of other methods have not been established. In the present study, we evaluated radiologic findings for cylindrical cervical cages over long-term follow up periods. METHODS: During 4 year period, radiologic findings of 138 patients who underwent anterior cervical fusion with cylindrical cage were evaluated at 6, 12, 24, and 36 postoperative months using plain radiographs. We investigated subsidence, osteophyte formation (anterior and posterior margin), cage direction change, kyphotic angle, and bone fusion on each radiograph. RESULTS: Among the 138 patients, a minimum of 36 month follow-up was achieved in 99 patients (mean follow-up : 38.61 months) with 115 levels. Mean disc height was 7.32 mm for preoperative evaluations, 9.00 for immediate postoperative evaluations, and 4.87 more than 36 months after surgery. Osteophytes were observed in 107 levels (93%) of the anterior portion and 48 levels (41%) of the posterior margin. The mean kyphotic angle was 9.87degrees in 35 levels showing cage directional change. There were several significant findings : 1) related subsidence [T-score (p=0.039) and anterior osteophyte (p=0.009)], 2) accompanying posterior osteophyte and outcome (p=0.05). CONCLUSION: Cage subsidence and osteophyte formation were radiologically observed in most cases. Low T-scores may have led to subsidence and kyphosis during bone fusion although severe neurologic aggravation was not found, and therefore cylindrical cages should be used in selected cases.

Posterior Interspinous Fusion Device for One-Level Fusion in Degenerative Lumbar Spine Disease : Comparison with Pedicle Screw Fixation - Preliminary Report of at Least One Year Follow Up

OBJECTIVE: Transpedicular screw fixation has some disadvantages such as postoperative back pain through wide muscle dissection, long operative time, and cephalad adjacent segmental degeneration (ASD). The purposes of this study are investigation and comparison of radiological and clinical results between interspinous fusion device (IFD) and pedicle screw. METHODS: From Jan. 2008 to Aug. 2009, 40 patients underwent spinal fusion with IFD combined with posterior lumbar interbody fusion (PLIF). In same study period, 36 patients underwent spinal fusion with pedicle screw fixation as control group. Dynamic lateral radiographs, visual analogue scale (VAS), and Korean version of the Oswestry disability index (K-ODI) scores were evaluated in both groups. RESULTS: The lumbar spine diseases in the IFD group were as followings; spinal stenosis in 26, degenerative spondylolisthesis in 12, and intervertebral disc herniation in 2. The mean follow up period was 14.24 months (range; 12 to 22 months) in the IFD group and 18.3 months (range; 12 to 28 months) in pedicle screw group. The mean VAS scores was preoperatively 7.16+/-2.1 and 8.03+/-2.3 in the IFD and pedicle screw groups, respectively, and improved postoperatively to 1.3+/-2.9 and 1.2+/-3.2 in 1-year follow ups (p<0.05). The K-ODI was decreased significantly in an equal amount in both groups one year postoperatively (p<0.05). The statistics revealed a higher incidence of ASD in pedicle screw group than the IFD group (p=0.029). CONCLUSION: Posterior IFD has several advantages over the pedicle screw fixation in terms of skin incision, muscle dissection and short operative time and less intraoperative estimated blood loss. The IFD with PLIF may be a favorable technique to replace the pedicle screw fixation in selective case.

Endovascular Embolization of a de Novo True Posterior Communicating Artery Aneurysm 23 years After Surgical Clipping of an Ipsilateral Posterior Communicating Artery-internal Carotid Artery Aneurysm: A Case Report / 대한뇌혈관외과학회지

We describe a true posterior communicating artery (PCoA) aneurysm, which is an uncommon variant of intracranial aneurysm that was treated by endosaccular embolization. A 64-year-old woman was admitted for management of an unruptured left PCoA aneurysm. She had undergone microsurgical clipping of an ipsilateral internal carotid artery (ICA)-PCoA aneurysm 23 years prior to the current presentation. Angiography showed a saccular aneurysm 3 mm distal to the junction of the ICA and the fetal-type PCoA arising on the opposite side of the vessel to that of the previous clipping. Endovascular embolization was performed to occlude the lumen of the aneurysm while preserving the patency of the PCoA. Based on angiograms, hemodynamic stress seems to be the most feasible explanation for the de novo development of an aneurysm at the first acute bend within the PCoA in our patient. For this anatomical reason, endosaccular coil deployment was possible without the use of a balloon or stent.

Targeting a Safe Entry Point for C2 Pedicle Screw Fixation in Patients with Atlantoaxial Instability

OBJECTIVE: This investigation was conducted to evaluate a new, safe entry point for the C2 pedicle screw, determined using the anatomical landmarks of the C2 lateral mass, the lamina, and the isthmus of the pars interarticularis. METHODS: Fifteen patients underwent bilateral C1 lateral mass-C2 pedicle screw fixation, combined with posterior wiring. The C2 pedicle screw was inserted at the entry point determined using the following method : 4 mm lateral to and 4 mm inferior to the transitional point (from the superior end line of the lamina to the isthmus of the pars interarticularis). After a small hole was made with a high-speed drill, the taper was inserted with a 30 degree convergence in the cephalad direction. Other surgical procedures were performed according to Harm's description. Preoperatively, careful evaluation was performed with a cervical X-ray for C1-C2 alignment, magnetic resonance imaging for spinal cord and ligamentous structures, and a contrast-enhanced 3-dimensional computed tomogram (3-D CT) for bony anatomy and the course of the vertebral artery. A 3-D CT was checked postoperatively to evaluate screw placement. RESULTS: Bone fusion was achieved in all 15 patients (100%) without screw violation into the spinal canal, vertebral artery injury, or hardware failure. Occipital neuralgia developed in one patient, but this subsided after a C2 ganglion block. CONCLUSION: C2 transpedicular screw fixation can be easily and safely performed using the entry point of the present study. However, careful preoperative radiographic evaluation, regardless of methods, is mandatory.