Trends in Incidence and Treatment of Herniated Lumbar Disc in Republic of Korea : A Nationwide Database Study

Objective@#: This study aimed to determine the incidence and analyze trends of the herniated lumbar disc (HLD) based on a national database in the Republic of Korea (ROK) from January 2008 to December 2016. @*Methods@#: This study was a retrospective analysis of data obtained from the national health-claim database provided by the National Health Insurance Service for 2008–2016 using the International Classification of Diseases. The crude incidence and age-standardized incidence of HLD were calculated, and additional analysis was conducted according to age and sex. Changes in trends in treatment methods and some treatments were analyzed using the Korean Classification of Diseases procedure codes. @*Results@#: The number of patients diagnosed with HLD was 472245 in 2008 and increased to 537577 in 2012; however, it decreased to 478697 in 2016. The pattern of crude incidence and the standardized incidence were also similar. Overall, the incidence of HLD increased annually for the 30s, 40s, 50s, and 70s until 2012 and then decreased. However, the incidence of HLD for the 80s continued to increase. The crude incidence of HLD in female patients exceeded that of male patients in their middle age (30s or 40s) and was 1.5–1.6 times higher than in male patients in their 60s. The total number of open discectomy (OD) increased from 71598 in 2008 to 93942 in 2012 and then decreased to 85846 in 2016. The rate of younger patients (the 20s, 30s, and 40s) who underwent OD was decreased, and the rate of younger patients who underwent percutaneous endoscopic lumbar discectomy was increased. However, the rate of older patients (the 70s and 80s) who underwent OD was continuously increased. @*Conclusion@#: This nationwide data on HLD from 2008 to 2016 in the ROK demonstrated that the crude incidence and the standardized incidence increased until 2012 and then decreased. The annual crude incidence was different according to age and sex. These findings may be considered when deciding future health policy, especially in countries with a similar national health insurance system (or with plans to adopt).

Radiographic and Clinical Outcomes Following Pedicle Subtraction Osteotomy : Minimum 2-Year Follow-Up Data

Objective@#: The purpose of this study was to report the results of pedicle subtraction osteotomy (PSO) for fixed sagittal imbalance with a minimum 2-year follow-up. Besides, authors evaluated the effect of adjunctive multi-level posterior column osteotomy (PCO) on achievement of additional lumbar lordosis (LL) during PSO. @*Methods@#: A total of 31 consecutive patients undergoing PSO for fixed sagittal imbalance were enrolled and analyzed. Correction angle of osteotomized vertebra (PSO angle) and other radiographic parameters including pelvic incidence (PI), thoracic kyphosis, LL, and sagittal vertical axis (SVA) were evaluated. Clinical outcomes and surgical complications were also assessed. @*Results@#: The mean age was 66.0±9.3 years with a mean follow-up period of 33.2±10.5 months. The mean number of fused segments was 9.6±3.5. The mean operative time and surgical bleeding were 475.9±160.5 minutes and 1406.1±932.1 mL, respectively. The preoperative SRS-22 score was 2.3±0.7 and improved to 3.2±0.8 at the final follow-up. The mean PI was 54.5±9.5°. LL was changed from 7.0±28.9° to -50.2±13.2°. The PSO angle was 33.7±13.5° (15.6±20.1° preoperatively, -16.1±19.4° postoperatively). The difference of correction angle of LL (57.3°) was greater about 23.6° than which of PSO angle (33.7°). SVA was improved from 189.5±93.0 mm, preoperatively to 12.4±40.8 mm, postoperatively. There occurred six, eight, and 14 cases of complications at intraoperative, early (<2 weeks) postoperative, and late (≥2 weeks) postoperative period, respectively. Additional operations were needed in nine patients due to the complications. @*Conclusion@#: PSO could provide satisfactory results for patients with fixed sagittal imbalance regarding clinical and radiographic outcomes. Additional correction of LL could be achieved with conduction of adjunctive multi-level PCOs during PSO.

Clinical Efficacy of Intra-Operative Cell Salvage System in Major Spinal Deformity Surgery

OBJECTIVE: The purpose of this study was to determine the efficacy of intra-operative cell salvage system (ICS) to decrease the need for allogeneic transfusions in patients undergoing major spinal deformity surgeries.METHODS: A total of 113 consecutive patients undergoing long level posterior spinal segmental instrumented fusion (≥5 levels) for spinal deformity correction were enrolled. Data including the osteotomy status, the number of fused segments, estimated blood loss, intra-operative transfusion amount by ICS (Cell Saver®, Haemonetics©, Baltimore, MA, USA) or allogeneic blood, postoperative transfusion amount, and operative time were collected and analyzed.RESULTS: The number of patients was 81 in ICS group and 32 in non-ICS group. There were no significant differences in demographic data and comorbidities between the groups. Autotransfusion by ICS system was performed in 53 patients out of 81 in the ICS group (65.4%) and the amount of transfused blood by ICS was 226.7 mL in ICS group. The mean intra-operative allogeneic blood transfusion requirement was significantly lower in the ICS group than non-ICS group (2.0 vs. 2.9 units, p=0.033). The regression coefficient of ICS use was -1.036.CONCLUSION: ICS use could decrease the need for intra-operative allogeneic blood transfusion. Specifically, the use of ICS may reduce about one unit amount of allogeneic transfusion in major spinal deformity surgery.

Clinical Efficacy of Intra-Operative Cell Salvage System in Major Spinal Deformity Surgery

OBJECTIVE: The purpose of this study was to determine the efficacy of intra-operative cell salvage system (ICS) to decrease the need for allogeneic transfusions in patients undergoing major spinal deformity surgeries. METHODS: A total of 113 consecutive patients undergoing long level posterior spinal segmental instrumented fusion (≥5 levels) for spinal deformity correction were enrolled. Data including the osteotomy status, the number of fused segments, estimated blood loss, intra-operative transfusion amount by ICS (Cell Saver®, Haemonetics©, Baltimore, MA, USA) or allogeneic blood, postoperative transfusion amount, and operative time were collected and analyzed.

Total Deformity Angular Ratio as a Risk Factor for Complications after Posterior Vertebral Column Resection Surgery

OBJECTIVE: The aim of the present study was to identify whether the deformity angular ratio (DAR) influences the occurrence of complications after posterior vertebral column resection (PVCR) and to establish the DAR cut-off value.METHODS: Thirty-six consecutive patients undergoing PVCR from December 2010 to October 2016 were reviewed. The relationships between the total, sagittal, and coronal DAR and complications were assessed using receiver operator characteristics curves. The patients were divided into two groups according to a reference value based on the cut-off value of DAR. Demographic, surgical, radiological, and clinical outcomes were compared between the groups.RESULTS: There were no significant differences in the patient demographic and surgical data between the groups. The cut-off values for the total DAR (T-DAR) and the sagittal DAR (S-DAR) were 20.2 and 16.4, respectively (p=0.018 and 0.010). Both values were significantly associated with complications (p=0.016 and 0.005). In the higher T-DAR group, total complications (12 vs. 21, p=0.042) and late-onset complications (3 vs. 9, p=0.036) were significantly correlated with the T-DAR. The number of patients experiencing complications (9 vs. 11, p=0.029) and the total number of complications (13 vs. 20, p=0.015) were significantly correlated with the S-DAR. Worsening intraoperative neurophysiologic monitoring was more frequent in the higher T-DAR group (2 vs. 4) than in the higher S-DAR group (3 vs. 3). There was no difference in neurological deterioration between the groups after surgery.CONCLUSION: Both the T-DAR and the S-DAR are risk factors for complications after PVCR. Those who had a T-DAR >20.2 or S-DAR >16.4 experienced a higher rate of complications after PVCR.

Clinical and Radiological Outcomes of Posterior Vertebral Column Resection for Severe Spinal Deformities

OBJECTIVE: The aim of this study was to investigate clinical and radiological outcomes of patients who underwent posterior vertebral column resection (PVCR) by a single neurosurgeon in a single institution.METHODS: Thirty-four consecutive patients with severe spinal deformities who underwent PVCR between 2010 and 2016 were enrolled. The radiographic measurements included a kyphotic angle of PVCR levels (VCR angle), sagittal vertical axis (SVA), thoracic kyphosis, lumbar lordosis (LL), and spinopelvic parameters. The data of surgical time, estimated blood loss, duration of hospital stay, complications, intraoperative neurophysiologic monitoring, and the Scoliosis Research Society (SRS)-22 questionnaire were collected using a retrospective review of medical records.RESULTS: The VCR angle, LL, and SVA values were significantly corrected after surgery. The VCR and LL angle were changed from the average of 38.4±32.1° and −22.1±39.1° to −1.7±29.4° (p < 0.001) and −46.3±23.8° (p=0.001), respectively. The SVA was significantly reduced from 103.6±88.5 mm to 22.0±46.3 mm (p=0.001). The clinical results using SRS-22 survey improved from 2.6±0.9 to 3.4±0.8 (p=0.033). There were no death and permanent neurological deficits after PVCR. However, complications occurred in 19 (55.9%) patients. Those patients experienced a total of 31 complications during- and after surgery. Sixteen reoperations were performed in twelve (35.3%) patients. The incidence of transient neurological deterioration was 5.9% (two out of 34 patients).CONCLUSION: Severe spinal deformities can be effectively corrected by PVCR. However, the PVCR technique should be utilized limitedly because surgery-related serious complications are relatively common.

Freehand S2 Alar-Iliac Screw Placement Using K-Wire and Cannulated Screw: Technical Case Series

OBJECTIVE: Among the various sacropelvic fixation methods, S2 alar-iliac (S2AI) screw fixation has several advantages compared to conventional iliac wing screw. However, the placement of S2AI screw still remains a challenge. The purpose of this study was to describe a novel technique of free hand S2AI screw insertion using a K-wire and cannulated screw, and to evaluate the accuracy of the technique.METHODS: S2AI screw was inserted by free hand technique in sixteen consecutive patients without any fluoroscopic guidance. The gearshift was advanced to make a pilot hole passing through the sacroiliac joint and directing the anterior inferior iliac spine. A K-wire was placed through the pilot hole. After introducing a cannulated tapper along with the K-wire, a cannulated S2AI screw was installed over the K-wire.RESULTS: Thirty-three S2AI screws were placed in sixteen consecutive patients. Thirty-two screws were cannulated screws, and one screw was a conventional non-cannulated screw. Thirty out of 32 (93.8%) cannulated screws were accurately positioned, whereas two cannulated screws and one non-cannulated screw violated lateral cortex of the ilium.CONCLUSION: The technique using K-wire and cannulated screw can provide accurate placement of free hand S2AI screw.

Total Deformity Angular Ratio as a Risk Factor for Complications after Posterior Vertebral Column Resection Surgery

OBJECTIVE: The aim of the present study was to identify whether the deformity angular ratio (DAR) influences the occurrence of complications after posterior vertebral column resection (PVCR) and to establish the DAR cut-off value. METHODS: Thirty-six consecutive patients undergoing PVCR from December 2010 to October 2016 were reviewed. The relationships between the total, sagittal, and coronal DAR and complications were assessed using receiver operator characteristics curves. The patients were divided into two groups according to a reference value based on the cut-off value of DAR. Demographic, surgical, radiological, and clinical outcomes were compared between the groups. RESULTS: There were no significant differences in the patient demographic and surgical data between the groups. The cut-off values for the total DAR (T-DAR) and the sagittal DAR (S-DAR) were 20.2 and 16.4, respectively (p=0.018 and 0.010). Both values were significantly associated with complications (p=0.016 and 0.005). In the higher T-DAR group, total complications (12 vs. 21, p=0.042) and late-onset complications (3 vs. 9, p=0.036) were significantly correlated with the T-DAR. The number of patients experiencing complications (9 vs. 11, p=0.029) and the total number of complications (13 vs. 20, p=0.015) were significantly correlated with the S-DAR. Worsening intraoperative neurophysiologic monitoring was more frequent in the higher T-DAR group (2 vs. 4) than in the higher S-DAR group (3 vs. 3). There was no difference in neurological deterioration between the groups after surgery. CONCLUSION: Both the T-DAR and the S-DAR are risk factors for complications after PVCR. Those who had a T-DAR >20.2 or S-DAR >16.4 experienced a higher rate of complications after PVCR.

Clinical and Radiological Outcomes of Posterior Vertebral Column Resection for Severe Spinal Deformities

OBJECTIVE: The aim of this study was to investigate clinical and radiological outcomes of patients who underwent posterior vertebral column resection (PVCR) by a single neurosurgeon in a single institution. METHODS: Thirty-four consecutive patients with severe spinal deformities who underwent PVCR between 2010 and 2016 were enrolled. The radiographic measurements included a kyphotic angle of PVCR levels (VCR angle), sagittal vertical axis (SVA), thoracic kyphosis, lumbar lordosis (LL), and spinopelvic parameters. The data of surgical time, estimated blood loss, duration of hospital stay, complications, intraoperative neurophysiologic monitoring, and the Scoliosis Research Society (SRS)-22 questionnaire were collected using a retrospective review of medical records. RESULTS: The VCR angle, LL, and SVA values were significantly corrected after surgery. The VCR and LL angle were changed from the average of 38.4±32.1° and −22.1±39.1° to −1.7±29.4° (p < 0.001) and −46.3±23.8° (p=0.001), respectively. The SVA was significantly reduced from 103.6±88.5 mm to 22.0±46.3 mm (p=0.001). The clinical results using SRS-22 survey improved from 2.6±0.9 to 3.4±0.8 (p=0.033). There were no death and permanent neurological deficits after PVCR. However, complications occurred in 19 (55.9%) patients. Those patients experienced a total of 31 complications during- and after surgery. Sixteen reoperations were performed in twelve (35.3%) patients. The incidence of transient neurological deterioration was 5.9% (two out of 34 patients). CONCLUSION: Severe spinal deformities can be effectively corrected by PVCR. However, the PVCR technique should be utilized limitedly because surgery-related serious complications are relatively common.

Freehand S2 Alar-Iliac Screw Placement Using K-Wire and Cannulated Screw: Technical Case Series

OBJECTIVE: Among the various sacropelvic fixation methods, S2 alar-iliac (S2AI) screw fixation has several advantages compared to conventional iliac wing screw. However, the placement of S2AI screw still remains a challenge. The purpose of this study was to describe a novel technique of free hand S2AI screw insertion using a K-wire and cannulated screw, and to evaluate the accuracy of the technique. METHODS: S2AI screw was inserted by free hand technique in sixteen consecutive patients without any fluoroscopic guidance. The gearshift was advanced to make a pilot hole passing through the sacroiliac joint and directing the anterior inferior iliac spine. A K-wire was placed through the pilot hole. After introducing a cannulated tapper along with the K-wire, a cannulated S2AI screw was installed over the K-wire. RESULTS: Thirty-three S2AI screws were placed in sixteen consecutive patients. Thirty-two screws were cannulated screws, and one screw was a conventional non-cannulated screw. Thirty out of 32 (93.8%) cannulated screws were accurately positioned, whereas two cannulated screws and one non-cannulated screw violated lateral cortex of the ilium. CONCLUSION: The technique using K-wire and cannulated screw can provide accurate placement of free hand S2AI screw.

Surgical Removal of a Ruptured Radiculomedullary Artery Aneurysm: A Case Report

Subarachnoid hemorrhage due to a solitary spinal aneurysm is extremely rare, and diagnosis and treatment are challenging. We report a rare case of a ruptured radiculomedullary artery aneurysm in a patient with Behçet disease. A 49-year-old man presented with severe lower abdominal and leg pain. Magnetic resonance imaging was performed and an enhanced intradural-extramedullary lesion at the T12 spinal level with subarachnoid hemorrhage was identified. Diagnostic spinal angiography was performed to evaluate the vascular lesion, and a radiculomedullary artery aneurysm at the T12 level was identified. We performed surgical resection of the aneurysm and a good neurological outcome was obtained.

Proximal Junctional Kyphosis and Proximal Junctional Failure Following Adult Spinal Deformity Surgery

The purpose of this review is the current understanding of proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) following adult spinal deformity (ASD) surgery. We carried out a systematic search of PubMed for literatures published up to September 2017 with “proximal junctional kyphosis,”“proximal junctional failure,” and “adult spinal deformity” as search terms. A total of 98 literatures were searched. The 37 articles were included in this review. PJK is multifactorial in origin and likely results from variable risk factors. PJF is a progressive form of the PJK spectrum including bony fracture, subluxation between UIV and UIV+1, failure of fixation, neurological deficit, which may require revision surgery for proximal extension of fusion. Soft tissue protections, adequate selection of the UIV, prophylactic rib fixation, hybrid instrumentation such as hooks, vertebral cement augmentation at UIV and UIV+1, adequate selection material of rods and age-appropriate spinopelvic alignment goals are strategies to minimize PJK and PJF. The ability to perform aggressive global realignment of spinal deformities has also led to the discovery of new complications such as the PJK and PJF. Continuous research on PJK and PJF should be proceeded in order to comprehend the pathophysiology of these complications.

Effectiveness and Safety of Tranexamic Acid in Spinal Deformity Surgery

OBJECTIVE: Spinal deformity surgery has the potential risk of massive blood loss. To reduce surgical bleeding, the use of tranexamic acid (TXA) became popular in spinal surgery, recently. The purpose of this study was to determine the effectiveness of intra-operative TXA use to reduce surgical bleeding and transfusion requirements in spinal deformity surgery. METHODS: A total of 132 consecutive patients undergoing multi-level posterior spinal segmental instrumented fusion (≥5 levels) were analyzed retrospectively. Primary outcome measures included intraoperative estimated blood loss (EBL), transfusion amount and rate of transfusion. Secondary outcome measures included postoperative transfusion amount, rate of transfusion, and complications associated with TXA or allogeneic blood transfusions. RESULTS: The number of patients was 89 in TXA group and 43 in non-TXA group. There were no significant differences in demographic or surgical traits between the groups except hypertension. The EBL was significantly lower in TXA group than non-TXA group (841 vs. 1336 mL, p=0.002). TXA group also showed less intra-operative and postoperative transfusion requirements (544 vs. 812 mL, p=0.012; 193 vs. 359 mL, p=0.034). Based on multiple regression analysis, TXA use could reduce surgical bleeding by 371 mL (37 % of mean EBL). Complication rate was not different between the groups. CONCLUSION: TXA use can effectively reduce the amount of intra-operative bleeding and transfusion requirements in spinal deformity surgery. Future randomized controlled study could confirm the routine use of TXA in major spinal surgery.

Long-Term Follow-Up Results of Anterior Cervical Inter-Body Fusion with Stand-Alone Cages

OBJECTIVE: The purpose of this study was to evaluate long-term follow-up radiologic/clinical outcomes of patients who underwent anterior cervical discectomy and inter-body fusion (ACDF) with stand-alone cages (SAC) in a single academic institution. METHODS: Total 99 patients who underwent ACDF with SAC between February 2004 and December 2012 were evaluated retrospectively. A total of 131 segments were enrolled in this study. Basic demographic information, radiographic [segmental subsidence rate, fusion rate, C2-7 global angle, and segmental angle changes)/clinical outcomes (by Odom's criteria and visual analog score (VAS)] and complications were evaluated to determine the long-term outcomes. RESULTS: The majority were males (55 vs. 44) with average age of 53.2. Mean follow-up period was 62.9 months. The segmental subsidence rate was 53.4% and fusion rate was 73.3%. In the subsidence group, anterior intervertebral height (AIH) had more tendency of subsiding than middle or posterior intervertebral height (p=0.01). The segmental angle led kyphotic change related to the subsidence of the AIH. Adjacent segmental disease was occurred in 18 (18.2%) patients. Total 6 (6%) reoperations were performed at the index level. There was no statistical significance between clinical and radiological outcomes. But, overall long-term clinical outcome by Odom's criteria was unsatisfactory (64.64%). The neck and arm VAS score were increased by over time. CONCLUSION: Long-term outcomes of ACDF with SAC group were acceptable but not satisfactory. For optimal decision making, more additional comparative long-term outcome data is needed between ACDF with SAC and ACDF with plating.

Surgical Outcome of Adult Idiopathic Chiari Malformation Type 1

OBJECTIVE: The pathophysiology of idiopathic Chiari malformation (CM) type 1 is disturbance of free cerebrospinal fluid (CSF) flow and restoration of normal CSF flow is the mainstay of treatment. Additional migration of the medulla oblongata in pediatric patients is referred to as CM type 1.5, but its significance in adult patients is unknown. This study is to compare surgical outcomes of adult idiopathic CM type 1.5 with that of type 1. METHODS: Thirty-eight consecutive adult patients (M : F=11 : 27; median, 33.5; range, 18–63) with syringomyelia due to idiopathic CM type 1 were reviewed. Migration of the medulla oblongata was noted in 13 patients. The modified McCormick scale (MMS) was used to evaluate functional status before and one year after surgery. All patients underwent foramen magnum decompression and duroplasty. Factors related to radiological success (≥50% decrease in the diameter of the syrinx) were investigated. The follow-up period was 72.7±55.6 months. RESULTS: Preoperative functional status were MMS I in 11 patients and MMS II in 14 of CM type 1 and MMS I in 8 and II in 5 of CM type 1.5. Of patients with MMS II, 5/14 patients in group A and 3/5 patients in group B showed improvement and there was no case of deterioration. Radiological success was achieved in 32 (84%) patients and restoration of the cisterna magna (p=0.01; OR, 46.5) was the only significant factor. CONCLUSION: Migration of the medulla oblongata did not make a difference in the surgical outcome when the cisterna magna was restored.

Posterior Trans-Dural Repair of Iatrogenic Spinal Cord Herniation after Resection of Ossification of Posterior Longitudinal Ligament

Iatrogenic spinal cord herniation is a rare complication following spinal surgery. We introduce a posterior trans-dural repair technique used in a case of thoracic spinal cord herniation through a ventral dural defect following resection of ossification of the posterior longitudinal ligament (OPLL) in the cervicothoracic spine. A 51-year-old female was suffering from paraplegia after laminectomy alone for cervicothoracic OPLL. Magnetic resonance imaging revealed a severely compressed spinal cord with pseudomeningocele identified postoperatively. Cerebrospinal fluid leak and iatrogenic spinal cord herniation persisted despite several operations with duroplasty and sealing agent. Finally, the problems were treated by repair of the ventral dural defect with posterior trans-dural duroplasty. Several months after surgery, the patient could walk independently. This surgical technique can be applied to treat ventral dural defect and spinal cord herniation.

Accuracy of Free Hand Pedicle Screw Installation in the Thoracic and Lumbar Spine by a Young Surgeon: An Analysis of the First Consecutive 306 Screws Using Computed Tomography

STUDY DESIGN: A retrospective cross-sectional study. PURPOSE: The purpose of this study is to evaluate the accuracy and safety of free-hand pedicle screw insertion performed by a young surgeon. OVERVIEW OF LITERATURE: Few articles exist regarding the safety of the free-hand technique without inspection by an experienced spine surgeon. METHODS: The index surgeon has performed spinal surgery for 2 years by himself. He performed fluoroscopy-assisted pedicle screw installation for his first year. Since then, he has used the free-hand technique. We retrospectively reviewed the records of all consecutive patients undergoing pedicle screw installation using the free-hand technique without fluoroscopy in the thoracic or lumbar spine by the index surgeon. Incidence and extent of cortical breach by misplaced pedicle screw was determined by a review of postoperative computed tomography (CT) images. RESULTS: A total of 36 patients received 306 free-hand placed pedicle screws in the thoracic or lumbar spine. A total of 12 screws (3.9%) were identified as breaching the pedicle in 9 patients. Upper thoracic spine was the most frequent location of screw breach (10.8%). Lateral breach (2.3%) was more frequent than any other direction. Screw breach on the right side (9 patients) was more common than that on the left side (3 patients) (p<0.01). CONCLUSIONS: An analysis by CT scan shows that young spine surgeons who have trained under the supervision of an experienced surgeon can safely place free-hand pedicle screws with an acceptable breach rate through repetitive confirmatory steps.

Does Obesity Make an Influence on Surgical Outcomes Following Lumbar Microdiscectomy?

OBJECTIVE: The purpose of this study was to evaluate the effect of patients' bod mass index (BMI) on surgical outcomes following one-level lumbar microdiscectomy. METHODS: From June 2003 to March 2007, 129 patients underwent one-level lumbar microdiscectomy performed at a single institution. We divided the patients into 3 groups, depending on BMI. A retrospective study was conducted among the 3 groups. The operation time, estimated blood loss (EBL), postoperative hospital day, recurrent disc herniation, intraoperative durotomy, and postoperative epidural steroid injection were analyzed. Regression models were used to predict the relationship between BMI and surgical outcomes including operation time and EBL. RESULTS: As BMI is greater, as the operation time is longer and the EBL is more. In particular, linear regression model analysis implied that 2.35 minute in the operation time is longer and 8.89cc in EBL is more, as BMI of 1 kg/m2 is increased. No statistically relevant differences were observed for postoperative hospital day, recurrent disc herniation, intraoperative durotomy, and postoperative epidural steroid injection. CONCLUSION: The operation time and EBL was significantly increased in obesity, but there were no differences in surgical outcomes. Our results demonstrated that higher BMI are not likely to encounter heightened morbidity in lumbar microdiscectomy.

A Case of Intradural-Extramedullary Form of Primary Spinal Cysticercosis Misdiagnosed as an Arachnoid Cyst

We describe a rare case of intradural-extramedullary primary spinal cysticercosis. A 42-year-old man visited our institute for lower back pain. He denied having consumed raw meet. Magnetic resonance (MR) images revealed an intradural pure cystic mass at the L3-L4 level. A radiologic diagnosis of spinal arachnoid cyst was established. Three years later, he complained of aggravated back pain, and follow-up MR examination showed a markedly expanded cyst, occupying the subarachnoid space from the T11 to the S1 level. L2 hemilaminectomy was performed, and a yellowish infected cyst bulged out through the dural opening. The cyst was removed en bloc. The histopathological findings of the cyst were consistent with parasitic infection. Serum enzyme-linked immunosorbent assay (ELISA) confirmed the presence of spinal cysticercosis. As there was no intracranial lesion, the final diagnosis was primary spinal cysticercosis, which is very rare. MR imaging is a sensitive diagnostic tool for detecting cystic lesions in the spine; however, it is difficult to distinguish cysticercosis from non-infectious cysts such as an arachnoid cyst without using gadolinium enhancement. Clinicians treating spinal cysts with an unusual clinical course should include cysticercosis as a differential diagnosis. We recommend contrast-enhanced MR imaging and serum ELISA in the diagnostic work-up of such cases.

Comparison between Two Different Cervical Interbody Fusion Cages in One Level Stand-alone ACDF: Carbon Fiber Composite Frame Cage Versus Polyetheretherketone Cage

OBJECTIVE: The authors conducted a retrospective study to compare the implantation of carbon fiber composite frame cages (CFCFCs) to the implantation of polyetheretherketone (PEEK) cages after anterior cervical discectomy for cervical degenerative disc disease. In addition, the predictive factors that influenced fusion or subsidence were investigated. METHODS: A total of 58 patients with single-level degenerative disc disease were treated with anterior cervical discectomy and implantation of stand-alone cages; CFCFCs were used in 35 patients, and PEEK cages were used in 23 patients. Preoperative and postoperative radiological and clinical assessments were performed. RESULTS: During the mean follow-up period of 41 months, fusion occurred in 43 patients (74.1%), and subsidence developed in 18 patients (31.0%). Pain decreased in all patients, and the patients' satisfaction rate was 75.9%. Neither fusion nor subsidence was related to the clinical outcome. There were no significant differences in the clinical and radiological outcomes between the CFCFC and the PEEK cage groups. Smoking history (p=0.023) was significantly associated with pseudarthrosis, and cage height (> or =7mm) (p=0.037) were significantly associated with subsidence. CONCLUSION: The clinical and radiological results were similar between the CFCFC and the PEEK cage groups. Fusion or subsidence did not affect the clinical outcomes. Smoking history and cage height (> or =7mm) were predictive factors for pseudarthrosis or subsidence in anterior cervical discectomy and fusion with stand-alone cages.