Analysis of sagittal parameters for easier and more accurate determination of cervical spine alignment.

Cross-sectional comparative study. This study aimed to analyze the role of cervical parameters, in terms of the perception process, when evaluating cervical sagittal balance on an X-ray image. Reports on the role of cervical parameters in the perception of cervical sagittal balance have not been made. The study included 4 board-certified neurosurgeons and 6 residents of a neurosurgical department. They were instructed to answer a total of 40 questions. The parameter that was the most helpful in deriving the answer was checked. The correct answer rate, dependency on the parameter, and correct answer contribution of the parameter were analyzed. Among the various parameters, 5 parameters [C2-7 angle (C2-7A), T1 slope minus cervical lordosis (T1s-CL), C2 slope (C2s), C7 slope (C7s), and C2-7 sagittal vertical axis) were selected. The simple parameter (C2s, C7s) has a higher dependency and correct answer contribution than the complex parameter (C2-7A, T1s-CL). The angular (C2-7A, T1s-CL, C2s, C7s) parameters have a higher dependency; however, both the length and angular parameters correct answer contribution were similar. The cervical parameters that have simpler properties were highly preferred and had a lower perception error.

The safety and effectiveness of lumbar drainage for cerebrospinal fluid leakage after spinal surgery.

PURPOSE: Cerebrospinal fluid (CSF) leakage is a frequent complication after spinal surgery. The lumbar drainage procedure (LDP) is the preferred method for early closure of a dural tear. This study was conducted to assess the safety and effectiveness of LDP after spinal surgery. MATERIALS AND METHODS: We retrospectively reviewed 122 patients (55 male and 67 female) who underwent LDP after spinal surgery between January 2010 and June 2021. LDP was performed on patients with suspected CSF leakage due to a dural tear during spinal surgery or in whom mixed-color CSF was observed in the hemo-drain after surgery. LDP was performed aseptically by a resident according to our institution's protocol, and the amount drained was from 200cc to 300cc per day. Absolute bed rest was maintained during the lumbar drainage period. The hemo-drain was opened to confirm that CSF was no longer mixed or oozing, at which time the lumbar drain was removed. Culture was performed at the drain tip when the lumbar drain was removed. RESULTS: The spinal surgery level was cervical in 23 patients, thoracic in 27 patients, and lumbar in 72 patients. The mean duration of the indwelling lumbar drain was 7.2 days (2 days-18 days), and the mean amount of drainage was 1198.2cc (100cc-2542cc). Among the 122 patients, the CSF leakage in 101 patients was resolved with the initial procedure, but 21 patients required re-insertion. Of those 21 patients, improper insertion due to a technical problem occurred in 15 patients, poor line fixation occurred in 2 patients, and CSF leakage was again observed after removal of the lumbar drain in 4 patients. In only 1 case was open surgery done after LDP because follow-up magnetic resonance imaging showed a suspected infection. During lumbar drainage, 76 patients used antibiotics, and 46 patients did not. Four patients showed bacterial growth in the tip culture, and 3 of them had been using antibiotics. All 4 of those patients were treated without complications and discharged. Among the 122 patients, 1 patient was discharged with left hemiparesis due to cerebral venous infarction (CVI) and hemorrhage after LDP, and 1 patient underwent re-operation because the CSF collection was not resolved. CONCLUSIONS: No major complications such as systemic infection, deep vein thrombosis, or aspiration pneumonia occurred during the lumbar drainage, except for 1 patient (0.8%) with CVI caused by over-drainage. One patient (0.8%) required open surgery after LDP, but no cases of systemic infection occurred while maintaining lumbar drainage, irrespective of antibiotic use. In conclusion, LDP is a safe and effective treatment for CSF leakage after spinal surgery.

Failure to Obtain Baseline Signals of Transcranial Motor-Evoked Potentials in Spine Surgery: Analysis of the Reasons.

OBJECTIVE: Among the various intraoperative neurophysiologic monitoring (IONM) techniques, transcranial motor-evoked potential (Tc-MEP) has recently become the most widely used method to monitor motor function. However, we often find that Tc-MEP is not sufficiently detected at the start of surgery. Therefore, we aimed to analyze the reasons and risk factors for not detecting sufficient baseline signal of Tc-MEP from the beginning of spinal surgery. METHODS: We categorized IONM data from 1058 patients who underwent spine surgeries at a single institution from 2014 to 2020 and categorized them into 2 groups: 1) "poor MEP" if Tc-MEP could not be sufficiently obtained and 2) "normal MEP" if Tc-MEP could be sufficiently obtained from the surgery. We analyzed the patient's age, gender, underlying disease, operation type, level numbers, baseline motor function, existence of pathologic reflex, myelopathy, and duration from the onset and clinical diagnosis. RESULTS: The rate of failure to obtain sufficient baseline Tc-MEP signals in spine surgery was 21.8% (231/1058). Multivariate analysis showed significant associations of existence of diabetes mellitus, myelopathy, thoracic spine surgery, baseline motor deficit and tumor, and trauma disease with loss of meaningful and interpretable signals in baseline Tc-MEP (P < 0.05). Only 15 of 231 patients (6.4%) showed a trend of signal recovery after decompression procedures. CONCLUSIONS: Various factors (myelopathy, diabetes mellitus, thoracic surgery, baseline motor deficit, tumor, and trauma) were closely related to not obtaining sufficient baseline signals for Tc-MEP. When operating on patients with these considerations, we need to consider the efficacy and usefulness of Tc- MEP.

Screw Insertional Torque Measurement in Spine Surgery: Correlation With Bone Mineral Density and Hounsfield Unit.

OBJECTIVE: Achieving successful fusion during spine surgery is dependent on rigid pedicle screw fixation. To assess fixation strength, the insertional torque can be measured during intraoperative screw fixation. This study aimed to explore the technical feasibility of measuring the insertional torque of a pedicle screw, while investigating its relationship with bone density. METHODS: Thoraco-lumbar screw fixation fusion surgery was performed on 53 patients (mean age, 65.5 ± 9.8 years). The insertional torque of 284 screws was measured at the point passing through the pedicle using a calibrated torque wrench, with a specially designed connector to the spine screw system. The Hounsfield units (HU) value was determined by assessing the trabecular portion of the index vertebral body on sagittal computed tomography images. We analyzed the relationship between the measured insertional torque and the following bone strength parameters: bone mineral density (BMD) and HU of the vertebral body. RESULTS: The mean insertion torque was 105.55 ± 58.08 N∙cm and T-score value (BMD) was -1.14 ± 1.49. Mean HU value was 136.37 ± 57.59. Screw insertion torque was positively correlated with BMD and HU in whole patients. However, in cases of osteopenia, all variables showed very weak correlations with insertional torque. In patients with osteoporosis, there was no statistically significant correlation between BMD and torque strength; HU showed a significant correlation. CONCLUSION: The insertional torque of screw fixation significantly correlated with bone density (BMD and HU). HU measurements showed greater clinical significance than did BMD values in patients with osteoporosis.

Analysis of Parameters That Can Predict the Cervical Sagittal Vertical Axis in Cervical Fusion Surgery.

OBJECTIVE: The absolute value of the cervical sagittal parameters cannot be guaranteed with certainty on all follow-up cervical radiographs. With the assumption that neck posture changes can occur at any time at each follow-up radiographic session, we examined whether the sagittal parameters change meaningfully and identified the factors most closely related to the C2-C7 sagittal vertical axis (SVA). METHODS: We enrolled 200 patients who had undergone either anterior cervical fusion (n = 100) or posterior cervical fusion (n = 100). The craniovertebral angle (CVA), mandible angle (MA), occipital slope (Os), C2 slope (C2s), C7 slope (C7s), and C2-C7 SVA were measured on 2 different follow-up radiographs after surgery. The C2-C7 angle (C2-C7A) and changes (Δ) in the sagittal parameters between the 2 radiographs were then calculated. RESULTS: The ΔC2s and ΔCVA showed a very strong correlation with the ΔC2-C7 SVA (r = |0.70-0.93|). An independent t test showed a statistically significant difference for multiple sagittal parameters (i.e., ΔMA, ΔOs, ΔC2s, ΔC7s, and ΔCVA) between the large and small ΔC2-C7 SVA groups. In contrast, the change in the C2-C7A was without statistical significance. A stepwise multivariate regression analysis revealed a high adjusted R2 value (0.841) between the ΔC2-C7 SVA and 2 parameters (standardized coefficient: ΔCVA, -0.563; ΔC2s, -0.398). CONCLUSIONS: During cervical fusion surgery, the CVA was the most predictable parameter reflecting the C2-C7 SVA in various analyses. The upper cervical parameters (Os and C2s) provided more explanatory power regarding the C2-C7 SVA changes than did the lower cervical parameter (C7s) or the presence of cervical lordosis (C2-C7A).

Effect of natural extract eye drops in dry eye disease rats.

AIM: To investigate the therapeutic effect of natural extract eye drops containing bee venom, musk, and deer antlers in dry eye disease (DED) animal models. METHODS: Scopolamine-injected DED rats and lacrimal gland-excised rats were allocated into control, saline, and natural extract groups respectively and a normal group (lacrimal gland excision was not performed) in lacrimal gland-excised rats. After eye drop instillation 4 times a day for 5d, corneal fluorescein staining (CFS) scores, tear MUC5AC levels, and tear lactic dehydrogenase (LDH) levels were measured. RESULTS: In scopolamine-injected rats, the natural extract-treated group had significantly lower CFS scores (1.7±0.5, 4.7±1.4, 3.8±1.9, P=0.006) and tear LDH levels (0.10±0.01, 0.19±0.01, 0.16±0.08 OD, P=0.014) but higher tear MUC5AC levels (12.9±3.7, 7.9±2.0, 9.7±3.6 ng/mL, P=0.041) compared with the control and saline-treated groups. There were no significant differences between the control and saline-treated groups. In lacrimal gland-excised rats, the natural extract-treated group also had lower CFS scores (4.3±1.2, 11.5±2.3, 9.0±1.9, P<0.001, P=0.001) and tear LDH levels (0.30±0.08, 0.48±0.12, 0.39±0.05 OD, P<0.05) but higher tear volume (4.3±0.9, 1.9±0.7, 2.8±1.1 mm, P=0.005, P=0.124) and tear MUC5AC levels (8.2±2.0, 2.9±1.2, 5.4±2.2 ng/mL, P<0.001, P=0.047) compared with the control and saline-treated groups. There were no significant differences in the CFS scores, tear MUC5AC level, and tear LDH level between the normal and natural extract-treated groups. CONCLUSION: The natural extract consisting of bee venom, musk, and deer antlers may have effectiveness in DED treatment by restoring the damaged ocular surface, increasing tear volume, and recovering the tear mucin layer in DED rats.

Macrolide Resistance and Its Impacts on M. Pneumoniae Pneumonia in Children: Comparison of Two Recent Epidemics in Korea.

PURPOSE: The aim of this study was to investigate the change in macrolide resistance rate in pediatric Mycoplasma pneumoniae pneumonia and to evaluate the influence of macrolide-resistant M. pneumoniae (MRMP) on the clinical course of disease, by comparing 2 recent, consecutive epidemics in Korea. METHODS: A total of 250 patients with M. pneumoniae pneumonia admitted to a single tertiary hospital were enrolled in this study. Detection of MRMP was based on specific point mutations in domain V of the 23S rRNA gene. The medical records of enrolled patients were reviewed retrospectively, and the clinical courses and laboratory data were compared. RESULTS: The macrolide resistance rate of M. pneumoniae was 51.1% (48/94) in the 2011 epidemic, and 87.2% (136/156) in the 2015 epidemic. All MRMP isolates had the A2063G point mutation. In comparison of 2 epidemics, the mean age of patients with M. pneumoniae pneumonia was increased, and the total febrile days and febrile days after initiation of macrolides were prolonged in the 2015 epidemic. Overall severity of MRMP or macrolide-susceptible M. pneumoniae (MSMP) pneumonia over 2 epidemics was not significantly changed. However, the proportion of patients who had a fever lasting more than 72 hours after initiation of macrolides and who received corticosteroid treatment were higher in MRMP pneumonia during 2 epidemics. CONCLUSIONS: The macrolide resistance rate of M. pneumoniae has risen rapidly over 2 recent, consecutive epidemics, and this has been associated with a prolonged clinical course and increased use of corticosteroids to treat pediatric M. pneumoniae pneumonia.

Prevalence and Characteristics of Musculoskeletal Pain in Korean Farmers.

OBJECTIVE: To investigate the prevalence and characteristics of musculoskeletal pain (MSK) pain in Korean farmers using initial survey data of Farmers' Cohort for Agricultural Work-Related MSK pain (FARM) study. METHODS: Farmers (534 females and 479 males; mean age 57.2±7.5 years) who owned or rented a farm and belonged to an agricultural cooperative unit were recruited. Presence of pain for each body part (neck, shoulder, arm/elbow, wrist/hand/finger, low back, leg/foot), and characteristics of MSK pain (prevalence, location, duration, severity, and frequency) during the last year was assessed. Additionally, demographic data such as farming duration, history of prior injury, and workload (low, moderate, somewhat hard, or hard) were collected using structured questionnaires. RESULTS: Almost all subjects (n=925; 91.3%) complained of pain in more than one body part. The frequency order was low back (63.8%), leg/foot (43.3%), shoulder (42.9%), wrist/hand/finger (26.6%), arm/elbow (25.3%), and neck (21.8%). Low back pain was more frequent in those with over 30 years of farming experience (odds ratio [OR], 1.40; 95% confidence interval, 1.08-1.81). MSK pain was related to history of prior injury (OR, 2.18-5.24; p<0.05) in all body parts except for leg/foot, and very hard workload was associated with low back, leg/foot, neck, shoulder, and wrist/hand/finger pain (OR, 2.88-10.83; p<0.05). CONCLUSION: Most Korean farmers experience MSK pain; furthermore, there is a significant association between pain, history of prior injury, and workload, suggestive of the necessity of coping and preventive strategies to reduce injury or workload.

Farmers' Cohort for Agricultural Work-Related Musculoskeletal Disorders (FARM) Study: Study Design, Methods, and Baseline Characteristics of Enrolled Subjects.

BACKGROUND: The ongoing Farmers' Cohort for Agricultural Work-related Musculoskeletal Disorders (FARM) study was developed to evaluate health status and related factors in farmers. METHODS: Farmers in Kangwon Province, South Korea, were recruited. Baseline characteristics were determined using questionnaires about sociodemographic and health characteristics and agricultural work-related factors. In addition, laboratory examinations (lumbar spinal radiography and serologic testing) were conducted. RESULTS: The FARM study covers eight rural areas and recruited 1013 subjects (534 women; mean [standard deviation {SD}] age, 57.2 [7.5] years). Musculoskeletal pain in multiple areas was reported by 925 subjects (91.3%), and low back pain (63.8%) was the most frequent site of pain. Farmer's Stress Inventory (mean [SD], 77.7 [10.2]; range, 28-112] and subjective stress index (mean [SD], 5.3 [2.4]; range, 0-10) were above median scale values, reflecting a stressful condition, while the EuroQol-5D-3L index and the EuroQol-Visual Analog Scale scores were high (mean [SD], 0.9 [0.1]; range -0.171-1 and mean [SD], 67.7 [18.7]; range 0-100, respectively), reflecting good life quality. In total, 53% of participants had worked in farming for more than 30 years, and workers involved in dry-field farming comprised the largest subgroup (41.5%). Most participants (94.3%) had no more than a high school education, and families with annual income below 20 million won constituted the largest subgroup (36.3%). CONCLUSIONS: The FARM study may provide data on the current health status and related sociodemographic and agricultural work-related risk factors in Korean farmers, with the goal of providing a scientific basis for developing coping interventions and preventive strategies.