The purpose of this study was to evaluate and compare the biomechanical behavior of the lumbar spine after posterior decompression with the spinous process osteotomy (SPiO) technique or the conventional laminectomy (CL) technique using a finite element (FE) model.
Materials and Methods
Three validated lumbar FE models (L2-5) which represented intact spine and two decompression models using SPiO and CL techniques at the L3-4 segment were developed. In each model, the ranges of motion, the maximal von Mises stress of the annulus fibrosus, and the intradiscal pressures at the index segment (L3-4) and adjacent segments (L2-3 and L4-5) under 7.5 Nm moments were analyzed. Facet contact forces were also compared among three models under the extension and torsion moments.
Compared to the intact model, the CL and SPiO models had increased range of motion and annulus stress at both the index segment (L3-4) and the adjacent segments under flexion and torsion. However, the SPiO model demonstrated a reduced range of motion and annulus stress than the CL model. Both CL and SPiO models had an increase of facet contact force at the L3-4 segment under the torsion moment compared to that of the intact model. Under the extension moment, however, three models demonstrated a similar facet contact force even at the L3-4 model.
Both decompression methods lead to postoperative segmental instability compared to the intact model. However, SPiO technique leads to better segmental stability compared to the CL technique.
Lumbar spinal stenosis; spinous process osteotomies; conventional laminectomy; finite element model
The purpose of this study was to investigate the effects of unilateral pedicle screw fixation on the fusion segment and the superior adjacent segment after one segment lumbar fusion using validated finite element models.
Materials and Methods
Four L3-4 fusion models were simulated according to the extent of decompression and the method of pedicle screws fixation in L3-4 lumbar fusion. These models included hemi-laminectomy with bilateral pedicle screw fixation in the L3-4 segment (BF-HL model), total laminectomy with bilateral pedicle screw fixation (BF-TL model), hemi-laminectomy with unilateral pedicle screw fixation (UF-HL model), and total laminectomy with unilateral pedicle screw fixation (UF-TL model). In each scenario, intradiscal pressures, annulus stress, and range of motion at the L2-3 and L3-4 segments were analyzed under flexion, extension, lateral bending, and torsional moments.
Under four pure moments, the unilateral fixation leads to a reduction in increment of range of motion at the adjacent segment, but larger motions were noted at the fusion segment (L3-4) in the unilateral fixation (UF-HL and UF-TL) models when compared to bilateral fixation. The maximal von Mises stress showed similar patterns to range of motion at both superior adjacent L2-3 segments and fusion segment.
The current study suggests that unilateral pedicle screw fixation seems to be unable to afford sufficient biomechanical stability in case of bilateral total laminectomy. Conversely, in the case of hemi-laminectomy, unilateral fixation could be an alternative option, which also has potential benefit to reduce the stress of the adjacent segment.
Unilateral pedicle screw fixation; lumbar fusion surgery; adjacent segment degeneration; finite element model
This study was designed to investigate the characteristics of Korean adrenomyeloneuropathy (AMN) patients.
Materials and Methods
We retrospectively selected 12 Korean AMN patients diagnosed by clinical analysis and increased plasma content of very long chain fatty acids.
All 12 patients were men. Patient ages at symptom onset ranged from 18 to 55 years. Family history was positive in two patients. The phenotype distributions consisted of AMN without cerebral involvement in seven patients, AMN with cerebral involvement in two patients, and the spinocerebellar phenotype in three patients. Nerve conduction studies revealed abnormalities in four patients and visual evoked tests revealed abnormalities in three patients. Somatosensory evoked potential tests revealed central conduction defects in all of the tested patients. Spinal MRI showed diffuse cord atrophy or subtle signal changes in all 12 patients. Brain MRI findings were abnormal in six of the nine tested patients. These brain abnormalities reflected the clinical phenotypes. Mutational analysis identified nine different ABCD1 mutations in 10 of 11 tested patients. Among them, nine have been previously reported and shown to be associated with various phenotypes; one was a novel mutation.
In conclusion, the present study is the first to report on the clinical and mutational spectrum of Korean AMN patients, and confirms various clinical presentations and the usefulness of brain MRI scan.
Adrenoleukodystrophy; adrenomyeloneuropathy; ataxia; very long chain fatty acid; ABCD1
Anti-tumor necrosis factor-alpha (TNF-α) medications represent a major advancement in the management of chronic inflammatory diseases. However, these agents are associated with increased risks of tuberculosis (TB) and other serious infections. The aim of this study was to evaluate the incidences of such disease among tertiary hospitals in Korea.
Materials and Methods
We retrospectively studied patients who received anti-TNF-α therapy; we reviewed serious infections including TB that developed within 6 months after initiation of anti-TNF-α therapy. Data concerning patient demographics, types of anti-TNF-α agents, concomitant immunosuppressive drugs use, and infection details were collected.
A total 175 patients treated with infliximab (n=72) or adalimumab (n=103) with the following conditions were enrolled: Crohn's disease, 34 (19.4%); ulcerative colitis, 20 (11.4%); ankylosing spondylitis, 82 (46.9%); and rheumatoid arthritis, 39 (22.2%). There were 18 cases (6.0%) of serious infections. The most common site of serious infection was the intra-abdomen (n=6), followed by TB (n=3), skin and soft tissue (n=3), bone and joints (n=2), ocular neurons (n=2), lower respiratory tract (n=1), and urinary tract (n=1). Of the 175 patients, only 3 cases showed development of TB. Furthermore, of all those who developed TB, none had taken anti-TB chemoprophylaxis prior to treatment with an anti-TNF agent due to negative screening results.
Serious infections with anti-TNF-α therapy were uncommon among tertiary hospitals in Korea; TB was the second most frequent infection. Nevertheless, there were no TB reactivations after anti-TB chemoprophylaxis. Accordingly, physicians should be aware of TB in subjects undergoing anti-TNF-α therapy, especially in countries with a high prevalence of TB.
Tumor necrosis factor-alpha; tuberculosis; infection
It has been reported that daily recombinant human growth hormone (GH) treatment showed beneficial effects on growth in prepubertal children with idiopathic short stature (ISS). The present study aimed to validate the GH (Eutropin®) effect on growth promotion and safety after short-term GH treatment.
Materials and Methods
This study was an open-label, multicenter, interventional study conducted at nine university hospitals in Korea between 2008 and 2009. Thirty six prepubertal children with ISS were enrolled in this study to receive 6-month GH treatment. Yearly growth rate, height standard deviation score (SDS), and adverse events were investigated during treatment.
After 26 weeks of GH treatment, the height velocity significantly increased by 6.36±3.36 cm/year (p<0.001). The lower end of one-sided 95% confidence interval was 5.22 cm/year, far greater than the predefined effect size. The gain in height SDS at week 26 was 0.57±0.27 (p<0.0001). Bone age significantly increased after GH treatment, however, bone maturation rate (bone age for chronological age) showed limited advancement. This 26-week GH treatment was effective in increasing serum levels of insulin-like growth factor (IGF)-I and IGF binding protein (IGFBP)-3 from baseline (p<0.0001). Eutropin was well tolerated and there were no withdrawals due to adverse events. No clinically significant changes in laboratory values were observed.
This 6-month daily GH treatment in children with ISS demonstrated increased height velocity, improved height SDS, and increased IGF-I and IGFBP-3 levels with a favorable safety profile.
Treatment outcome; safety; growth hormone; child; short stature; idiopathic
We describe herein a case of life-threatening hypoglycemia due to spurious elevation
of glucose concentration during the administration of ascorbic acid in a type 2 diabetic patient. A 31-year-old female was admitted for proliferative diabetic retinopathy
treatment and prescribed high dose ascorbic acid. During hospitalization, she suddenly lost her consciousness and her glucose concentration was 291 mg/dL, measured using self-monitoring blood glucose (SMBG) device, while venous blood glucose concentration was 12 mg/dL. After intravenous injection of 50% glucose solution, the patient became alert. We reasoned that glucose measurement by SMBG device was interfered by ascorbic acid. Physicians should be aware of this interference; high dose ascorbic acid may cause spurious elevation of glucose concentration when measuring with SMBG devices.
Self-monitoring of blood glucose; ascorbic acid; hypoglycemia
Hypocalcemia is the most common complication after total thyroidectomy. The purpose of this study was to determine whether measurement of intact parathyroid hormone (i-PTH) level in thyroidectomy patients could predict hypocalcemia.
Materials and Methods
We performed a prospective study of patients undergoing total thyroidectomy. Serum concentration of i-PTH, total calcium (Ca), ionized calcium (Ca2+), phosphate (P), magnesium (Mg), and albumin were measured preoperatively and at 0 hour, 6 hours, 12 hours, 24 hours, 48 hours, and 72 hours postoperatively.
108 patients were recruited to the study. A total of 50 patients (46%) experienced hypocalcemia. The serum i-PTH concentration was linearly related to the time of measurement, while concentrations of P, Mg, albumin, Ca, and Ca2+ were not. We compared odds ratios, and found that the concentration of i-PTH at 6 hours post operation was the most closely related to the occurrence of hypocalcemic symptom. On ROC analysis using i-PTH level at 6 hours, an i-PTH level of 10.6 mg/dL was found to maximize both sensitivity and specificity at the same time point.
We found that i-PTH was a predictor of hypocalcemia, and that the earliest predictor of hypocalcemic symptoms was an i-PTH concentration lower than 10.6 mg/dL obtained 6 hours after total thyroidectomy.
Thyroidectomy; hypocalcemia; parathyroid hormone; surgery
In this report, we describe a Korean patient with May-Hegglin anomaly from a mutation of the MYH9 gene. The proband was a 21-year-old man with thrombocytopenia. He did not have a bleeding tendency. His neutrophil count was normal at 7490/mm3; however, the neutrophils contained abnormal basophilic inclusions in their cytoplasm. The platelet count was decreased at 15000/mm3 with giant platelets. Coagulation test results were not remarkable. Direct sequencing of MYH9 revealed that he was heterozygous for a mutation in exon 1, which was a 97T>A substitution mutation affecting codon 33, substituting tryptophan with arginine (Trp33Arg). Family study showed that both of his parents had normal phenotype and genotypes, indicating a de novo occurrence of the mutation in the proband.
May-Hegglin anomaly; MYH9; thrombocytopenia; Korean
A retrospective investigation of the clinical and radiologic features as well as the bronchoscopic appearance was carried out in patients with endobronchial aspergilloma.
Materials and Methods
Ten patients with endobronchial aspergilloma diagnosed by bronchoscopy and histological examination were identified at the Gyeongsang University Hospital of Korea, from May 2003 to May 2009.
The patients included 9 men and 1 woman, and the age of the patients ranged from 36 to 76 (median, 58 years). The associated diseases or conditions were: previous pulmonary tuberculosis in 7 patients, lung cancer in 2 patients, pulmonary resection in 1 patient, and foreign body of the bronchus in 1 patient. The chest radiologic finding showed fibrotic changes as a consequence of previous tuberculosis infection in 6 patients and a mass-like lesion in 2 patients. Two patients had a co-existing fungus ball, and an endobronchial lesion was suspected in only 2 patients on the CT scan. The bronchoscopic appearance was a whitish to yellow necrotic mass causing bronchial obstruction in 7 patients, foreign body with adjacent granulation tissue and whitish necrotic tissue in 1 patient, whitish necrotic tissue at an anastomosis site in 1 patient, and a protruding mass with whitish necrotic tissue in 1 patient.
An endobronchial aspergilloma is a rare presentation of pulmonary aspergilosis and is usually incidentally found in immunocompetent patients with underlying lung disease. It usually appears as a necrotic mass causing bronchial obstruction on bronchoscopy and can be confirmed by biopsy.
The embryologic origin of the omohyoid muscle is different from that of the other neck muscles. A number of variations such as the absence of muscle, variable sites of origin and insertion, and multiple bellies have been reported. However, variations in the inferior belly of the omohyoid muscle are rare. There have been no reports of the combined occurrence of the omohyoid muscle variation with the appearance of the levator glandulase thyroideae muscle. Routine dissection of a 51-year-old female cadaver revealed a duplicated omohyoid muscle and the appearance of the levator glandulae thyroideae muscle. In this case, the two inferior bellies of the omohyoid muscle were found to originate inferiorly from the superior border of the scapula. One of the inferior bellies generally continued to the superior belly with the tendinous intersection. The other inferior belly continued into the sternohyoid muscle without the tendinous intersection. In this case, the levator glandulae thyroideae muscle appeared on the left side, which attached from the upper border of the thyroid gland to the inferior border of the thyroid cartilage. These variations are significant for clinicians during endoscopic diagnosis and surgery because of the arterial and nervous damage due to iatrogenic injuries. The embryologic origins of the omohyoid and levator glandulae thyroideae muscles may be similar based on the descriptions in the relevant literature.
Variation; omohyoid muscle; levator glandulae thyroideae muscle; infrahyoid muscle
The purpose of this study is to investigate the mechanism of cellular proliferation of electromagnetic field (EMF) on human intervertebral disc (IVD) cells.
Materials and Methods
Human IVD cells were cultured three-dimensionally in alginate beads. EMF was exposed to IVD cells with 650Ω, 1.8 millitesla magnetic flux density, 60 Hz sinusoidal wave. Cultures were divided into a control and EMF group. Cytotoxicity, DNA synthesis and proteoglycan synthesis were measured by MTT assay, [3H]-thymidine, and [35S]-sulfate incorporation. To detect phenotypical expression, reverse transcription-polymerase chain reactions (RT-PCR) were performed for aggrecan, collagen type I, and type II mRNA expression. To assess action mechanism of EMF, IVD cells were exposed to EMF with NG-Monomethyl-L-arginine (NMMA) and acetylsalicylic acid (ASA).
There was no cytotoxicity in IVD cells with the EMF group in MTT assay. Cellular proliferation was observed in the EMF group (p < 0.05). There was no difference in newly synthesized proteoglycan normalized by DNA synthesis between the EMF group and the control. Cultures with EMF showed no significant change in the expression of aggrecan, type I, and type II collagen mRNA compared to the control group. Cultures with NMMA (blocker of nitric oxide) or ASA (blocker of prostaglandin E2) exposed to EMF demonstrated decreased DNA synthesis compared to control cultures without NMMA or ASA (p < 0.05).
EMF stimulated DNA synthesis in human IVD cells while no significant effect on proteoglycan synthesis and chondrogenic phenotype expressions. DNA synthesis was partially mediated by nitric oxide and prostaglandin E2. EMF can be utilized to stimulate proliferation of IVD cells, which may provide efficient cell amplification in cell therapy to degenerative disc disease.
Electromagnetic fields; intervertebral disc; nitric oxide; prostaglandin E2
The purpose of this study is to systematically review and analyze disasters involving South Korean hospitals from 1990 and to introduce a newly developed implement to manage patients' evacuation.
Materials and Methods
We searched for studies reporting disaster preparedness and hospital injuries in South Korean hospitals from 1990 to 2008, by using the Korean Studies Information Service System (KISS, copyright Korean Studies Information Co, Ltd, Seoul, Korea) and, simultaneously, hospital injuries which were reported and regarded as a disaster. Then, each study and injury were analyzed.
Five studies (3 on prevention and structure, 1 on implement of new device, and 1 on basic supplement to current methods) and 8 injuries were found within this period. During the evacuations, the mean gait speed of walking patients was 0.82 m/s and the mean time of evacuation of individual patients was 38.39 seconds. Regarding structure evaluation, almost all hospitals had no balconies in patient rooms; hospital elevators were placed peripherally and were insufficient in number. As a new device, Savingsun (evacuation elevator) was introduced and had some merits as a fast and easy tool, regardless of patient status or the height of hospital.
In South Korea, preparation for hospital disasters was noted to be insufficient but has involved various departments such as architectural, clinical, and building operations. In addition, Savignsun has been shown to effectively evacuate and save patients in a hospital disaster.
Injury; disaster; hospital; preparedness
Surgical treatment in the case of thoracolumbar burst fractures is very controversial. Posterior instrumentation is most frequently used, however, but the number of levels to be instrumented still remains a matter of debate.
Materials and Methods
A total of 94 patients who had a single burst fracture between T11 and L2 were selected and were managed using posterior instrumentation with anterior fusion when necessary. They were divided into three groups as follows; Group I (n = 28) included patients who were operated by intermediate segment fixation, Group II (n = 32) included patients operated by long segment fixation, and Group III (n = 34) included those operated by intermediate segment fixation with a pair of additional screws in the fractured vertebra. The mean follow-up period was twenty one months. The outcomes were analyzed in terms of kyphosis angle (KA), regional kyphosis angle (RA), sagittal index (SI), anterior height compression rate, Frankel classification, and Oswestry Disability Index questionnaire.
In Groups II and III, the correction values of KA, RA, and SI were much better than in Group I. At the final follow up, the correction values of KA (6.3 and 12.1, respectively) and SI (6.2 and 12.0, respectively) were in Groups II and III found to be better in the latter.
The intermediate segment fixation with an additional pair of screws at the fracture level vertebra gives results that are comparable or even better than long segment fixation and gives an advantage of preserving an extra mobile segment.
Thoracolumbar burst fracture; posterior instrumentation; intermediate segment fixation; fixation length; selective anterior fusion
To evaluate the merit of umbilical artery Doppler study as a predictive marker of perinatal outcome in preterm small for gestational age (SGA) infants.
Materials and Methods
A total of 218 patients at 27 - 36 weeks of gestational age (GA) who received antenatal umbilical artery Doppler velocimetry and delivered singleton infants with SGA. The ratio of peak-systolic to end-diastolic blood flow velocities (S/D) in the umbilical artery was measured in each patient. The patients were divided into 3 groups: the normal group with S/D ratios of less than 95th percentile (n = 134), elevated S/D ratio group of 95th or more percentile (n = 41), and those with absent/reversed end diastolic flow (n = 43). Maternal characteristics and neonatal outcomes of these groups were comparatively analyzed.
The gestational age (GA) at the time of diagnosis of SGA, the mean GA at delivery, and the mean birth weight showed statistically significant difference among three groups (p < 0.001). Also, poor perinatal outcome was significantly increased in infants with abnormal S/D ratio (13.4% vs. 31.7% vs. 67.4%, p < 0.001). Multivariate logistic regression analysis revealed umbilical artery Doppler study as a significant independent factor for prediction of poor perinatal outcome (odds ratio: 3.7, 95% confidence interval 1.4 - 9.5, p = 0.007).
Antenatal umbilical artery Doppler velocimetry is shown as a significantly efficient marker in predicting perinatal outcome in preterm SGA infants.
Preterm small for gestational age infant; umbilical artery Doppler velocimetry; perinatal outcome
Schwannomas, also known as neurinomas or neurilemmomas, are generally benign, slow-growing neoplasms originating in any nerve that has a Schwann cell sheath. These neoplasms are rare among the spindle cell mesenchymal tumors of the gastrointestinal tract, but develop most commonly in the stomach representing 0.2% of all gastric tumors. We present the case of a 57-year-old female patient with a large schwannoma in the stomach that was palpable in the abdomen. She underwent subtotal gastrectomy under suspicion of gastrointestinal stromal tumor (GIST), but post-operative histopathological and immunohistochemical findings showed a fascicular arrangement of spindle cell with pallisading nuclei, and positive for S-100 protein with negative smooth muscle actin (SMA). These results confirmed schwannoma as the diagnosis.
Schwannoma; stomach; submucosal tumor; S-100 protein
Endobronchial tuberculosis (EBTB) presenting as right middle lobe syndrome (RMLS) is an uncommon clinical condition. We investigated the clinical characteristics in patients with EBTB presenting as RMLS.
Patients and Methods
We retrospectively reviewed the records of 22 patients with EBTB presenting as RMLS who were diagnosed at our hospital from 2003 to 2006.
Its occurrence was more common in females than males (F, 18; M, 4). The mean age was 70.3 ± 8.5 years, and 17 patients were above the age of 65 years. Cough with sputum was the most common manifestation and 2 patients were asymptomatic. In bronchoscopic analysis, the most common finding was edematous-type EBTB, which was found in 15 patients, followed by actively caseating type in 6 and tumorous type in 1. Acid-fast bacilli (AFB) staining for bronchial washing fluid was positive in only 5 patients: 1 with edematous type and 4 with actively caseating type. Bronchoscopic biopsy showed chronic granulomatous inflammation in 16 patients. Follow-up chest X-ray after treatment showed complete disappearance of the lesion in 2 patients, more than 50% improvement in 5, less than 50% improvement in 5, and no change of lesion in 4.
Edematous-type EBTB was the most common type of EBTB presenting as RMLS, and it usually occurred in elderly patients. Culturing for mycobacterium and histologic examination by bronchoscopy are necessary for proper diagnosis in these patients.
Endobronchial tuberculosis; right middle lobe syndrome
A 69-year-old male was diagnosed in February 2004 with stage IV extranodal marginal zone B cell lymphoma involving the mediastinal nodes, lung parenchyma and bone marrow with high LDH. Shortness of breath developed following the 5th course of Rituximab-CHOP chemotherapy (cyclophosphamide, Vincristine, Doxorubicin, Prednisolone). Bronchoscopy guided transbronchial lung biopsy revealed interstitial thickening and type II pneumocyte activation, compatible with interstitial pneumonitis. After treatment with prednisolone a complete resolution of the dyspnea was observed. The patient was well on routine follow-up at the outpatient clinic, with no progression of lymphoma or interstitial pneumonitis.
Interstitial pneumonitis; rituximab; lymphoma
Of two major forms (myo- and chiro-inositol) of inositols, only chiro-inositol enhances the activity of proteins involved in intracellular glucose metabolism. This study aims to determine the urinary myo-/chiro-inositol ratio in type 1 and type 2 diabetes patients and compare its ratio with the normal control group. The 24-hour urinary myo- and chiro-inositols in 71 Korean diabetes patients and 39 control subjects have been quantified using high-performance liquid chromatography, and their ratios have been evaluated as indices of insulin resistance. The level of 24-hour urinary myo-inositol was significantly higher in both type 1 and type 2 diabetes than with the control group, whereas the urinary chiro-inositol in type 1 or type 2 diabetes was lower than that in normal subjects. The myo-/chiro-inositol ratio in diabetes patients was higher than that in the control group. Twenty four-hour urinary myo-/chiro-inositol ratios were significantly elevated in type 1 and type 2 diabetes patients compared to the control group, suggesting that a high ratio of urinary myo-/chiro-inositol in type 2 diabetes patients might be used for an index of insulin resistance.
Myo-inositol; chiro-inositol; inositol; insulin resistance; diabetes mellitus