Effect of saline irrigation temperature difference on postoperative acute pain and hypothermia during biportal endoscopic spine surgery.

BACKGROUND: Recently, enhanced recovery after surgery (ERAS) protocols have attracted attention; they emphasize on avoiding intraoperative hypothermia while performing lumbar fusion surgery. However, none of the studies have reported the protocol for determining the temperature of saline irrigation during biportal endoscopic spine surgery (BESS) procedure. This study evaluated the effectiveness of warm saline irrigation during BESS in acute postoperative pain and inflammatory reactions. MATERIALS AND METHODS: Fifty-five patients who underwent BESS procedure were retrospectively analyzed for the incidence of perioperative hypothermia (< 36oC), postoperative inflammatory factors (white blood cells (WBC), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), interleukin-6 (IL-6), serum amyloid A (SAA)), and clinical outcomes (back visual analog scale (VAS) score, postoperative shivering). The patients were divided into the warm and cold saline irrigation groups. RESULTS: Hemoglobin, WBC, ESR, creatine kinase, and creatine kinase-muscle brain levels did not significantly differ between the warm and cold saline groups. The mean CRP, IL-6, and SAA levels were significantly higher in the cold saline group than in the warm saline group (p = 0.0058, 0.0028, and 0.0246, respectively); back VAS scores were also higher with a statistically significant difference until two days postoperatively (p < 0.001). During the entire procedure, the body temperature was significantly lower in the cold saline irrigation group, but the hypothermia incidence rate significantly differed 30 min after the operation was started. CONCLUSIONS: Using warm saline irrigation during BESS is beneficial for early recovery after surgery, as it is associated with reduced postoperative pain and complication rates.

How reliable is routine lumbar spine MRI for detection of renal cysts? Correlation with abdominal CT.

BACKGROUND: Incidental renal cysts are a very common finding in routine lumbar spine magnetic resonance imaging (MRI). However, there is no report of the renal cyst detection rate on routine lumbar spine MRI. PURPOSE: To determine the renal cyst detection rate in routine lumbar spine MRI based on findings of abdominal computed tomography (CT), and to investigate if the largest renal cyst seen by abdominal CT could be also detected by routine lumbar spine MRI. MATERIAL AND METHODS: A retrospective study was conducted of 70 patients who underwent both routine lumbar spine MRI and abdominal CT between December 2011 and January 2014. The detection rate of all renal cysts>5 mm as well as the largest renal cyst seen by abdominal CT were assessed in routine lumbar spine MRI. RESULTS: On routine lumbar spine MRI, the detection rate of renal cysts was 46.5% (73/157) for>5-mm renal cysts and 68.0% (34/50) for>10-mm renal cysts, correlating with abdominal CT. The detection rate of the largest renal cyst seen by abdominal CT was 60.0% (27/45). Non-detection of the largest renal cyst could be caused by upper positioning (n = 7), lateral positioning (n = 6), or relatively small cyst size (n = 5). CONCLUSION: Approximately half of renal cysts>5 mm and two-thirds of renal cysts>10 mm were detected on routine lumbar spine MRI. However, radiologists should be aware that kidney lesions may not be included in the scan coverage of routine lumbar spine MRI.

Prognostic factors for surgical outcomes including preoperative total knee replacement and knee osteoarthritis status in female patients with lumbar spinal stenosis.

STUDY DESIGN: A retrospective clinical case series. OBJECTIVE: To investigate knee osteoarthritis (KOA) and total knee replacement (TKR) status as prognostic factors for surgical outcomes in female patients with lumbar spinal stenosis (LSS). SUMMARY OF BACKGROUND DATA: There have been many reports on numerous prognostic factors for surgical outcomes in patients with degenerative lumbar conditions; however, there has been no report on the surgical outcome in patients who underwent spinal surgery with coexisting KOA and TKR. METHODS: This study included 141 female patients (mean age, 67.6 y) who underwent spinal surgery for LSS between January 2006 and December 2010. At 1 year postoperatively, surgical outcomes were measured using the Oswestry disability index (ODI). Various clinical factors including KOA and TKR were analyzed as prognostic factors for surgical outcomes. RESULTS: Mean average scores at preoperative evaluation were 26.1±6.6 in the no KOA group, 23.6±7.9 in the KOA group, and 30.4±6.7 in the TKR group (P<0.05). Mean average scores at postoperative 1 year were 13.8±8.5 in the no KOA group, 16.8±9.5 in the KOA group, and 21.4±5.7 in the TKR group (P<0.05, Mann-Whitney U test). Preoperative ODI scores were shown to be significantly affected by the TKR status only (P<0.05), and were significantly higher in the TKR patient group. ODI scores at postoperative 3 months were significantly correlated with the preoperative ODI and the operational level (P<0.05). At postoperative 1 year, ODI scores were shown to be affected by the operational level, the preoperative ODI, and the presence of advanced radiographic KOA (Kellgren/Lawrence grades III and IV) (P<0.05). CONCLUSIONS: A poor preoperative functional score, the presence of preoperative KOA, and longer operational levels were shown to be poor prognostic factors for the 1-year surgical outcome of LSS. Also, patients in the TKR group showed the worst ODI scores at preoperative and postoperative 1-year evaluations. Consideration of these factors when planning for spine surgery could be helpful in predicting the surgical outcomes of lumbar spinal surgery.

Multiscale distribution entropy analysis of short epileptic EEG signals.

This paper proposes an information-theoretic measure for discriminating epileptic patterns in short-term electroencephalogram (EEG) recordings. Considering nonlinearity and nonstationarity in EEG signals, quantifying complexity has been preferred. To decipher abnormal epileptic EEGs, i.e., ictal and interictal EEGs, via short-term EEG recordings, a distribution entropy (DE) is used, motivated by its robustness on the signal length. In addition, to reflect the dynamic complexity inherent in EEGs, a multiscale entropy analysis is incorporated. Here, two multiscale distribution entropy (MDE) methods using the coarse-graining and moving-average procedures are presented. Using two popular epileptic EEG datasets, i.e., the Bonn and the Bern-Barcelona datasets, the performance of the proposed MDEs is verified. Experimental results show that the proposed MDEs are robust to the length of EEGs, thus reflecting complexity over multiple time scales. In addition, the proposed MDEs are consistent irrespective of the selection of short-term EEGs from the entire EEG recording. By evaluating the Man-Whitney U test and classification performance, the proposed MDEs can better discriminate epileptic EEGs than the existing methods. Moreover, the proposed MDE with the moving-average procedure performs marginally better than one with the coarse-graining. The experimental results suggest that the proposed MDEs are applicable to practical seizure detection applications.

Prognostic factor analysis in patients with metastatic spine disease depending on surgery and conservative treatment: review of 577 cases.

BACKGROUND: To date, skillful medical management and advanced surgical techniques have provided increased quality of life with less postoperative morbidity in patients with spinal metastasis. We assessed the survival of patients with spinal metastasis according to two treatment modalities: surgery and conservative treatment. METHODS: From 2005 to 2010, a total of 577 patients (200 surgery, 377 conservative treatment) who had spinal metastasis were enrolled. Prognostic factors and survival were assessed by Cox regression and Kaplan-Meier analyses in patients receiving either surgery or conservative treatment. RESULTS: The mean age was 59.7 (range 21-87) years in the surgery group and 59.9 (range 28-90) years in the conservative treatment group. The major primary cancers were of lung, liver, and colorectal origin in the surgery group and lung, liver, and breast in the conservative group. The mean±SD Tokuhashi score in the surgery group was 8.12±3.09 and in the conservative group was 8.0±2.8 (not significant). The hazard ratio of the primary cancer group ranged from 1.870 to 3.217 compared to that of the most favorable primary cancer group in all patients. Survival was affected significantly by sex, adjuvant therapy, and postoperative survival in the surgery group and by clinical symptom, metastasis to major internal organ, and primary cancer origin in the conservative group. CONCLUSIONS: With this retrospective review of 577 cases of spinal metastasis, different prognostic factors depending on the treatment modality were discovered. Hence, consideration of these factors depending on the treatment modality could be helpful in treating patients with spinal metastasis.

Inflammatory cytokines induce fibrosis and ossification of human ligamentum flavum cells.

STUDY DESIGN: In vitro experiment using degenerated human ligamentum flavum (LF) and various inflammatory cytokines. OBJECTIVES: To examine the effect of inflammatory cytokines on LF cells and to identify their roles in the pathogenesis of LF hypertrophy and ossification. SUMMARY OF BACKGROUND DATA: Spinal stenosis is caused, in part, by hypertrophy and ossification of the LF, which are induced by the degenerative processes (ie, increased collagen synthesis and chondroid metaplasia) of ligament fibroblasts. Degenerated intervertebral disk spontaneously produces inflammatory cytokines, which might affect the adjacent LF through local milieu of the spinal canal. METHODS: The interlaminar portion of the LF was collected during surgical spinal procedures in 15 patients (age range, 49-78 y) with lumbar spinal stenosis. LF fibroblasts were isolated by enzymatic digestion of LF tissue. LF cell cultures were treated with various inflammatory cytokines: interleukin (IL)-1α, IL-6, tumor necrosis factor-α (TNF-α), prostaglandin E2 (PGE2), and nitric oxide (NO). Cytotoxicity was analyzed by MTT assays. DNA synthesis was measured with H-thymidine incorporation, and mRNA expression of types I, III, V, and XI collagen and osteocalcin were performed by reverse transcription-polymerase chain reaction. Histochemical stains such as Von Kossa were also performed to detect bone nodule formation. RESULTS: There was no cytotoxicity in the LF cells treated with each cytokine. There were significant increases in DNA synthesis and upregulated mRNA expression of types I, V, XI collagen and osteocalcin in LF cultures treated with various cytokines. LF cultures treated with IL-6, TNF-α, PGE2, and NO showed positive Von Kossa staining, indicating bone nodule formation from LF cells. CONCLUSIONS: Inflammatory cytokines (IL-6, TNF-α, PGE2, and NO) seem to play a crucial role in hypertrophy and ossification of LF. Degenerated, herniated intervertebral disks, and facet arthrosis may influence LF through inflammatory cytokines and cause hypertrophy and ossification of LF.

Link between the Nankai underthrust turbidites and shallow slow earthquakes.

Trench sediments such as pelagic clay or terrigenous turbidites have long been invoked to explain the seismogenic behavior of the megathrust fault (i.e., décollement). Recent numerous studies suggest that slow earthquakes may be associated with huge megathrust earthquake; however, controls on the slow earthquake occurrence remain poorly understood. We investigate seismic reflection data along the Nankai Trough subduction zone to understand the correlations between the spatial distribution of the broad turbidites and along-strike variations in shallow slow earthquakes and slip-deficit rates. This report presents a unique map of regional distribution of the three discrete Miocene turbidites that underthrust apparently along the décollement beneath the Nankai accretionary prism. A comparison of distributions of the Nankai underthrust turbidites, shallow slow earthquakes, and slip-deficit rates enables us to infer that the underthrust turbidites may cause primarily low pore-fluid overpressures and high effective vertical stresses across the décollement, leading to potentially inhibiting the slow earthquake occurrence. Our findings provide a new insight into potential role of the underthrust turbidites for shallow slow earthquakes at subduction zone.

A Comparative Analysis of Bi-Portal Endoscopic Spine Surgery and Unilateral Laminotomy for Bilateral Decompression in Multilevel Lumbar Stenosis Patients.

The clinical and radiological results before and after surgery were compared and analyzed for patients with multilevel lumbar stenosis who underwent bi-portal endoscopic spine surgery (BESS) and microscopic unilateral laminotomy for bilateral decompression (ULBD). We retrospectively identified 47 and 49 patients who underwent BESS and microscopic ULBD, respectively, who were diagnosed with multi-level lumbar stenosis. Clinical outcomes were evaluated using the visual analog scale score for both back and leg pain, and medication (pregabalin) use and Oswestry Disability Index (ODI) scores for overall treatment outcomes were used pre-operatively and at the final follow-up. Radiological outcomes were evaluated as the percentage of dura expansion volume, and percentage preservation of both facets and both lateral recess angles. The follow-up period of patients was about 17.04 months in the BESS group and about 16.90 months in the microscopic ULBD group. The back and leg visual analog scale (VAS) scores and average pregabalin use decreased more significantly in the BESS group than in the microscopic ULBD group (each p-value 0.0443, <0.001, 0.0378). All radiological outcomes were significantly higher in the BESS group than in the ULBD group. The change in ODI in two-level spinal stenosis showed a significantly higher value in the BESS group compared to the microscopic ULBD group (p-value 0.0335). Multilevel decompression with the BESS technique in multiple spinal stenosis is an adequate technique as it shows better clinical and radiological results than microscopic ULBD during a short-term follow-up period.

Surgical outcome of lumbar fusion surgery in patients with Parkinson disease.

STUDY DESIGN: Retrospective study. OBJECTIVES: To investigate the overall surgical outcome of lumbar fusion surgery in patients with Parkinson disease (PD). SUMMARY OF BACK GROUND DATA: Poor bone quality and muscular dysfunction are important clinical manifestations connected with musculoskeletal diseases in PD patients. These secondary changes caused by PD often result in spinal pathology, indicating spine operations for some patients with scoliosis, kyphosis, osteoporotic fracture, or degenerative spondylosis. However, little is known about the surgical outcome or prognosis of spine surgery in PD patients. METHODS: Lumbar fusion surgery was performed on 20 patients who had PD and degenerative spinal diseases. At the time of lumbar fusion surgery, the mean duration of PD, age, sex, the preoperative visual analog pain scale (VAS, 0 to 100 mm) for low back pain, Hoehn and Yahr staging, and other comorbidities were evaluated. Patients' postoperative clinical outcome was measured using the criteria of Kim and Kim and VAS for back pain. Radiographic assessment was made using plain films and a dynamogram. RESULTS: At the time of the spine surgery, Hoehn and Yahr staging of PD was from 1 to 2 in all patients. Only 1 patient had a satisfactory outcome; a good result according to Kim and Kim's criteria. The average postoperative VAS (mm) was 55.2, whereas the mean preoperative VAS (mm) was 53.9. Radiological assessment showed fusion status in 15 patients and probably no solid fusion mass in 5 patients. CONCLUSIONS: A poor surgical outcome would be inevitable because of the worsening of symptoms owing to the natural history of PD. Therefore, our current study suggested surgical indication should be exercised cautiously in the patients with PD and spinal stenosis.

Connection between high pore-fluid pressure and frictional instability at tsunamigenic plate boundary fault of 2011 Tohoku-Oki earthquake.

The 2011 Tohoku-Oki earthquake (M 9.0) rupture propagated along a shallow plate boundary thrust fault (i.e. decollement) to the trench, displaced the seafloor, and triggered a devastating tsunami. Physical properties of the underthrust sediments which control the rupture propagation are yet poorly known. We use a 2D seismic dataset to build velocity model for imaging and apply reverse time migration. We then calculate pore-fluid pressure along the decollement as the top boundary of underthrust sediments, and along the backstop interface as the boundary between undeformed structures in the continental plate and the severely deformed sediments in the accretionary prism. The results show that within horizontal distance of 40-22 km toward the trench, pore-fluid pressure is 82-60% higher than the hydrostatic pressure for both decollement and backstop interface. It then reduces to hydrostatic level for the backstop interface but remains 60-40% higher than hydrostatic level for the decollement, causing frictional instability in favor of fault rupture along the decollement. We report for the first time, by our knowledge, detailed seismic images of fluid-rich trapped bucket sediments, quantitative stress states, and fluid drainage conditions at shallow tsunamigenic portion of the Japan Trench, which are consistent with the seafloor and borehole observations.

Changes in retro-odontoid mass after upper cervical spine surgery.

A non-neoplastic mass posterior to the dens is termed a retro-odontoid mass (R-OM). This retrospective study evaluated radiographic and clinical outcomes and R-OM changes after upper cervical spine surgery. This study included 69 patients who underwent upper cervical spine surgery, including atlantoaxial fusion, occipitocervical fusion, or decompression. All patients underwent preoperative magnetic resonance imaging (MRI). Six-month follow-up MRI examinations were performed in 30 patients who had preoperative R-OMs. Radiographic outcomes of the anterior and posterior atlantodental intervals were measured using X-rays and computed tomography. The R-OM and space available for the cord (SAC) were measured using MRI. Clinical outcomes were evaluated using neck and arm pain visual analog scales, the Japanese Orthopedic Association score, the neck disability index, and the patient-reported subjective improvement rate. The anterior atlantodental interval decreased, while the posterior atlantodental interval and SAC increased postoperatively. Among the clinical outcomes, the neck and arm pain and the neck disability index decreased postoperatively, while the Japanese Orthopedic Association score increased. All clinical and radiographic outcomes improved postoperatively. The R-OM either decreased in size or disappeared after fusion surgery in all cases, except in one patient who underwent decompression surgery. In conclusion, stabilization through fusion surgery is essential for treating R-OM.

Percutaneous coronary intervention in patients with documented coronary vasospasm during long-term follow-up.

OBJECTIVE: Although recurring coronary artery spasm (CAS) may lead to the development of fixed atherosclerotic coronary stenosis (FS), the relationship between coronary atherosclerosis and CAS is still speculative. We evaluated the incidence of FS requiring percutaneous coronary intervention (PCI) in patients with documented CAS during long-term follow-up and analysed their clinical features. METHODS: Clinical data of 3556 patients during a median follow-up of 9.4 years after non-invasive ergonovine spasm provocation testing with echocardiographic monitoring of left ventricular wall motion (erg echo) were analysed. RESULTS: Erg echo documented CAS in 830 (23.3%) patients, who had higher frequencies of coronary risk factors than those without CAS. Patients with documented CAS on erg echo showed significantly lower 10-year overall (90.5% vs 94.2%, p<0.001) and PCI-free (97.4% vs 98.4%, p=0.002) survival rates than those without CAS. Documented CAS was an independent factor associated with later PCI after adjustment by either Cox regression model or Fine-Gray competing risk model. There was no significant difference in baseline clinical characteristics between patients who needed later PCI and those who did not. Among 28 patients who needed later PCI after documentation of CAS, the original CAS and later PCI territory were concordant in 25 (89.3%), while 3 (10.7%) showed discordance. CONCLUSIONS: CAS is a risk factor for the development of FS requiring PCI during long-term follow-up, and warrants physicians' vigilance and careful follow-up of patients with documented CAS and insignificant stenosis of major epicardial coronary arteries at the time of initial diagnosis.

Mantle-derived helium released through the Japan trench bend-faults.

Plate bending-related normal faults (i.e. bend-faults) develop at the outer trench-slope of the oceanic plate incoming into the subduction zone. Numerous geophysical studies and numerical simulations suggest that bend-faults play a key role by providing pathways for seawater to flow into the oceanic crust and the upper mantle, thereby promoting hydration of the oceanic plate. However, deep penetration of seawater along bend-faults remains controversial because fluids that have percolated down into the mantle are difficult to detect. This report presents anomalously high helium isotope (3He/4He) ratios in sediment pore water and seismic reflection data which suggest fluid infiltration into the upper mantle and subsequent outflow through bend-faults across the outer slope of the Japan trench. The 3He/4He and 4He/20Ne ratios at sites near-trench bend-faults, which are close to the isotopic ratios of bottom seawater, are almost constant with depth, supporting local seawater inflow. Our findings provide the first reported evidence for a potentially large-scale active hydrothermal circulation system through bend-faults across the Moho (crust-mantle boundary) in and out of the oceanic lithospheric mantle.

Transient fixation of L4 vertebra preserves lumbar motion and function in Lenke Type 5C and 6C scoliosis.

This study investigated the efficacy of a novel surgical method that relies on the transient fixation of L4 in Lenke Type 5C and 6C adolescent idiopathic scoliosis. Thirty-six transient surgically treated L4 fixation patients were retrospectively evaluated. The first surgery involved mechanical correction of scoliosis; the lowest instrumented vertebra (LIV) was L4. After an average of 1.3 years (range, 0.3-3.4), the second surgery to remove transient L4 pedicle screws was performed. Radiographic parameters and SRS-22 scores were measured. Cobb's angle, coronal balance, LIV tilting angle, and LIV coronal disc angle clearly improved after the first surgery (p < 0.01). After the second surgery, the corrected Cobb angle (p = 0.446) and coronal balance were maintained (p = 0.271). Although L3/S1 lumbar lordosis decreased after the first surgery (p < 0.01), after removal of transient L4 pedicle screws, it recovered slightly (p = 0.03). Similarly, the preoperative L3/4 lateral disc mobility eventually recovered after transient L4 screw removal (p < 0.01). The function domain of the SRS-22 showed better scores after removal of transient L4 screws (p = 0.04). L4 transient fixation surgery is beneficial for Lenke Type 5C and 6C scolioses that do not fully satisfy LIV (L3) criteria. It preserves L3/4 disc motion, increases functional outcomes, and maintains spinal correction and coronal balance.

Prevalence of Gastrointestinal and Cardiovascular Risk in Patients with Degenerative Lumbar Spinal Disease.

BACKGROUND: Limited information is available about the proportion of patients with degenerative lumbar spinal disease (DLSD) who have gastrointestinal (GI) and cardiovascular (CV) risk factors. Many DLSD patients are prescribed nonsteroidal anti-inflammatory drugs (NSAIDs) that are known to carry risks to the GI and CV systems by increasing GI bleeding and thromboembolic events. This study aimed to measure the prevalence of GI and CV risk in patients with DLSD and to ascertain whether the prescription of NSAIDs is in line with current guidelines. METHODS: This study included 153 patients with symptomatic DLSD who were planning to undergo lumbar spinal surgery. The GI profile was checked using the GI Standardized Calculator of Risk for Event system and CV risk was evaluated using the presence of metabolic syndrome. The conformity of the prescription of NSAIDs was investigated according to the recommendations in current guidelines. RESULTS: More than half of the patients (59.5%) had high or very high GI risk, and 66% of the patients were diagnosed with metabolic syndrome, which corresponds with CV risk. The rate of simultaneous GI and CV risk was 40.5% (n = 62 / 153; gastrointestinal Standardized Calculator of Risk for Event, > high and metabolic syndrome, yes). The actual prescription of NSAIDs was not in accordance with current guidelines. CONCLUSIONS: Two out of 3 patients had GI or CV risk factors, and approximately 40% of patients had both. Detailed assessment of GI and CV risk in patients with DLSD by using effective evaluation tools is mandatory for optimal medical treatment.

Comparison of mechanical motion profiles following instrumented fusion and non-instrumented fusion at the L4-5 segment.

PURPOSE: To investigate the difference in motion profiles between instrumented and non-instrumented fusion of the lumbar spine. METHOD: In vivo retrospective radiological analysis of dynamic (flexion-extension) lateral plain films was performed in different lumbar spine fusion types. Twenty-eight patients underwent lumbar fusion surgery at the L4/5 level. Fourteen patients underwent anterior fusion surgery without implantation, and the others underwent posterior instrumented fusion. Segmental angular motion was measured at the fused and adjacent levels using dynamic plain lateral film 2 years after operation. RESULTS: The anterior uninstrumented fusion group showed mean 2.0 degrees of segmental angular motion at the fused level compared with mean of 0.8 degrees in the posterior instrumented fusion group (P < 0.05). In contrast, at the proximal adjacent level, decreased angular motion (mean 7.7 degrees ) was noted in the anterior uninstrumented fusion group compared with mean 11.6 degrees in the posterior instrumented fusion group (P < 0.05). CONCLUSION: This study suggests that differing stiffness of fusion segments could cause different mechanical motion profiles at adjacent segments.

Mantle degassing along strike-slip faults in the Southeastern Korean Peninsula.

On September 12, 2016, a ML 5.8 earthquake hit Gyeongju in the southeastern part of the Korean Peninsula (SeKP), although the area is known to be far from the boundary of the active plate. A number of strike-slip faults are observed in heavily populated city areas (e.g., Busan, Ulsan, Pohang, and Gyeongju). However, dissolved gases related to the active faults have rarely been studied despite many groundwater wells and hot springs in the area. Here we report new results of gas compositions and isotope values of helium and carbon dioxide (CO2) in fault-related fluids in the region. Based on gas geochemistry, the majority of gas samples are abundant in CO2 (up to 99.91 vol.%). Measured 3He/4He ratios range from 0.07 to 5.66 Ra, showing that the mantle contribution is up to 71%. The range of carbon isotope compositions (δ13C) of CO2 is from -8.25 to -24.92‰, showing mantle-derived CO2 is observed coherently where high 3He/4He ratios appear. The weakening of faults seems to be related to enhanced pressures of fluids containing mantle-derived helium and CO2 despite the ductile lower crust underneath the region. Thus, we suggest that the SeKP strike-slip faults penetrate into the mantle through ductile shearing.

Sagittal plane analysis of adolescent idiopathic scoliosis after VATS (video-assisted thoracoscopic surgery) anterior instrumentations.

Radiographic sagittal plane analysis of VATS (video-assisted thoracoscopic surgery) anterior instrumentation for adolescent idiopathic scoliosis. This is retrospective study. To report, in details about effects of VATS anterior instrumentation on the sagittal plane. Evaluations of the surgical outcome of scoliosis have primarily studied in coronal plane correction, functional, and cosmetic aspects. Sagittal balance, as well as coronal balance, is important in functional spine. Recently, scoliosis surgery applying VATS has been increasingly performed. Its outcome has been reported several times; however, according to our search of the literature, the only one study partially mentioned. The study population was a total of 42 cases of idiopathic scoliosis patients (8 male, 34 female). Their mean age was 15.6 years (13 to 18 years). The 18 cases were Lenke IA type, 16 cases were Lenke IB type, and 8 cases were Lenke IC type. The preoperative Cobb's angle was 54.5 +/- 13.9 degrees. All patients were followed up for a minimum of 2 years and implanted, on average, at the 5.9 level (5 to 8 levels). The most proximal implant was the 4th thoracic spine, and the most distal implant was the 1st lumbar spine. Whole spine standing PA and lateral radiographs were taken before surgery, 2 months after surgery, and at the last follow up (range 24-48 months, mean 35 months). The C7 plumbline proximal junctional measurement (PJM), distal junctional measurement (DJM), thoracic kyphosis, and lumbar lordosis angles were measured and compared. In all cases, follow-ups were possible and survived till the last follow up. The Cobb's angle in coronal plane at the last follow up was 19.7 +/- 9.3 degrees and was corrected to 63.8% on average. The preoperative C7 sagittal plumbline before surgery was -13.9 +/- 29.1 mm, the final follow up was -9.9 +/- 23.8 mm, and the average positive displacement was 4 mm. Thoracic kyphosis was increased from preoperative 18.2 +/- 7.7 degrees to 22.4 +/- 7.2 degrees on average at the last follow up, and the increase was, on average, 4.2 degrees. The PJM angel was increased from 6.2+/- 4.3 degrees preoperative to 8.8 +/- 3.7 degrees at the last follow up, and the increment was, on the average, 2.6 degrees. The DJM angle before surgery was 6.8 +/- 5.1 degrees and 6.7 +/- 4 degrees at the last follow up, and did not change noticeably. Preoperative lumbar lordosis was 42 +/- 10.7 degrees and 43.5 +/- 11.1 degrees after surgery. Similarly, it did not change greatly. The scoliosis surgery applying VATS displaced the C7 sagittal plumb line by 4 mm to the anteriorly, increased thoracic kyphosis by 4.2 degrees, and increased PJM by 2.6 degrees. DJM and lumbar lordosis, before and after operation, were not significantly different. Although the surgical technique of VATS thoracic instrumentation is difficult to make the normal thoracic kyphosis, an acceptable sagittal balance can be obtained in Lenke type I adolescent idiopathic scoliosis using VATS.

The incidence of new vertebral compression fractures in women after kyphoplasty and factors involved.

PURPOSE: To identify the incidence of new vertebral compression fractures in women after kyphoplasty and to analyze influential factors in these patients. MATERIALS AND METHODS: One hundred and eleven consecutive female patients with osteoporotic vertebral compression fractures (VCFs) underwent kyphoplasty at 137 levels. These patients were followed for 15.2 months postoperatively. For the survey of new vertebral compression fractures, medical records and x-rays were reviewed, and telephone interviews were conducted with all patients. RESULTS: During that time 20 (18%) patients developed new VCFs. The rate of occurrence of new VCFs in one year was 15.5% using a Kaplan-Meier curve. Body mass index (BMI), symptom duration and kyphoplasty level were the statistically significant factors between the patient groups both with and without new VCFs after kyphoplasty. In the comparison between the adjacent and remote new VCF groups, the adjacent new VCF group showed a larger amount of polymethyl methacrylate (PMMA) use during kyphoplasty (p<0.05). Before kyphoplasty, 9.9% of the patients had been prescribed medication for osteoporosis, and 93.7% of the patients started or continued medication after kyphoplasty. The development of new VCFs was affected by the number of vertebrae involved in the kyphoplasty. However, the lower incidence rate (15.5%) of new compression fractures might be due to a greater percentage (93.7% in our study) of patients taking anti-osteoporotic medication before and/or after kyphoplasty. CONCLUSION: When kyphoplasty is planned for the management of patients with osteoporotic VCFs, the application of a small amount of PMMA can be considered in order to lower the risk of new fractures in adjacent vertebrae. The postoperative use of anti- osteoporotic medication is recommended for the prevention of new VCFs.