angfei Gu

Unilateral versus bilateral pedicle screw instrumentation for single-level minimally invasive transforaminal lumbar interbody fusion

Minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) has become an increasingly popular method of lumbar arthrodesis. However, there are few published studies comparing the clinical outcomes between unilateral and bilateral instrumented MIS TLIF. Sixty-five patients with degenerative lumbar spine disease were enrolled in this study. Thirty-one patients were randomized to the unilateral group and 34 to the bilateral group. Recorded demographic data included sex, age, preoperative diagnosis, and degenerated segment. Operative time, blood loss, hospital stay length, complication rates, and fusion rates were also evaluated. The Oswestry Disability Index (ODI) score and Visual Analog Scale (VAS) pain score data were obtained. All patients were asked to follow-up at 3 and 6 months after surgery, and once every 6 months thereafter. The mean follow-up was 26.6 months (range 18-36 months). The two groups were similar in sex, age, preoperative diagnosis, and operated level. The unilateral group had significantly shorter operative time, lower blood loss, and shorter hospital time than the bilateral group. The average postoperative ODI and VAS scores improved significantly in each group. No significant differences were found between the two groups in relation to ODI and VAS. All patients showed evidence of fusion at 12 months postoperatively. The total fusion rate, screw failure, and general complication rate were not significantly different. Results showed that single-level MIS TLIF with unilateral pedicle screw fixation would be sufficient in the management of preoperatively stable patients with lumbar degenerative disease. It seems that MIS TLIF with unilateral pedicle screw instrumentation is a better choice for single-level degenerative lumbar spine disease.

Diffusion Tensor Imaging Studies of Cervical Spondylotic Myelopathy: A Systemic Review and Meta-Analysis

A meta-analysis was conducted to assess alterations in measures of diffusion tensor imaging (DTI) in the patients of cervical spondylotic myelopathy (CSM), exploring the potential role of DTI as a diagnosis biomarker. A systematic search of all related studies written in English was conducted using PubMed, Web of Science, EMBASE, CINAHL, and Cochrane comparing CSM patients with healthy controls. Key details for each study regarding participants, imaging techniques, and results were extracted. DTI measurements, such as fractional anisotropy (FA), apparent diffusion coefficient (ADC), and mean diffusivity (MD) were pooled to calculate the effect size (ES) by fixed or random effects meta-analysis. 14 studies involving 479 CSM patients and 278 controls were identified. Meta-analysis of the most compressed levels (MCL) of CSM patients demonstrated that FA was significantly reduced (ES -1.52, 95% CI -1.87 to -1.16, P < 0.001) and ADC was significantly increased (ES 1.09, 95% CI 0.89 to 1.28, P < 0.001). In addition, a notable ES was found for lowered FA at C2-C3 for CSM vs. controls (ES -0.83, 95% CI -1.09 to -0.570, P < 0.001). Meta-regression analysis revealed that male ratio of CSM patients had a significant effect on reduction of FA at MCL (P = 0.03). The meta-analysis of DTI studies of CSM patients clearly demonstrated a significant FA reduction and ADC increase compared with healthy subjects. This result supports the use of DTI parameters in differentiating CSM patients from health subjects. Future researches are required to investigate the diagnosis performance of DTI in cervical spondylotic myelopathy.

Radiation exposure to surgeon in minimally invasive transforaminal lumbar interbody fusion with novel spinal locators.

Study Design: A prospective study. Objective: To further investigate the implication of our surface locator and intradermal locator to reduce the radiation exposure to surgeons in minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) surgery. Summary of Background Data: Our previous studies published in the journal have introduced our novel spinal locators effectively minimizing fluoroscopic time during minimally invasive spinal surgery. Methods: Twenty patients underwent MIS-TLIF surgery with G-arm fluoroscopy from January 2013 to June 2013. There were 10 patients in group A who underwent standard MIS-TLIF using our spinal locators, and the other 10 in group B underwent conventional MIS-TLIF without spinal locators. The radiation dosages to the arm, the finger, the whole body, thyroid gland, gonad gland, and the eye of the surgeon were measured by thermoluminescence badges for both groups. Results: All 20 patients (9 male, 11 female), aged from 48 to 77 years old, successfully underwent the surgery. The operation time was 171.20±10.28 minutes for group A and 189.80±11.99 minutes for group B. The fluoroscopy time was 49.60±7.32 seconds for group A and 68.40±7.62 seconds for group B, hence a reduction of 27.49% was observed. There was no correlation between operation time and exposure time for group A or group B. The radiation reduction was 35.28% for the arm, 17.95% for the finger, 45.23% for the whole body, 53.62% for the thyroid gland (protected), 52.44% for the thyroid gland (unprotected), 44% for gonad gland (protected), 36.42% for the gonad gland (unprotected), 59.42% for the eye (protected), and 59.70% for the eye (unprotected). Conclusion: The study indicated that radiation exposure to the surgeon would be effectively reduced in MIS-TLIF using our surface locator and intradermal locator, and it could be another practical choice for radiation-minimizing strategy.

Preoperative localization methods for minimally invasive surgery in lumbar spine: comparisons between a novel method and conventional methods.

Study Design: This is a prospective single-center nonrandomized control clinical study involving 220 patients who underwent the novel localization method or conventional methods preoperatively in a minimally invasive surgery in lumbar spine. Objective: To introduce a novel preoperative locator designed by the authors for a minimally invasive surgery in lumbar spine and to compare the novel localization method with conventional methods in mean localization time and the mean number of C-arm fluoroscopy use preoperatively. Summary of Background Data: Conventional localization methods for minimally invasive surgery in lumbar spine are associated with more fluoroscopy time and radiation exposure. We describe a novel preoperative locator to help localize spinal anatomic landmarks, minimize preoperative localization time, and decrease radiation exposure. There have been no prospective clinical reports published on the comparison of the novel localization method with conventional methods. Methods: A total of 220 patients, 86 (39.1%) men and 134 (60.9%) women with an average age of 53.8±16.4 years were prospectively evaluated. We divided all patients into 2 groups. Group A: the first 100 patients who received the conventional preoperative localization methods (the palpation method and the Kirschner wire method). Group B: the remaining 120 patients who localized the spinal levels with the help of the novel locator before surgery. The localization time and the number of C-arm fluoroscopy use preoperatively were recorded. Results: The mean localization time of patients in groups A and B were 7.37±3.77 and 3.85±2.45 minutes, respectively. The mean number of preoperative C-arm fluoroscopy use in groups A and B were 2.29 and 1.29. There was significant difference in mean localization time and the mean number of C-arm fluoroscopy use between groups A and B (P<0.05). There was no incidence of wrong-level surgery in both groups. Conclusions: The novel preoperative locator is a simple and practical device that can help to minimize preoperative localization time and decrease radiation exposure.

Significant Improvement of Puncture Accuracy and Fluoroscopy Reduction in Percutaneous Transforaminal Endoscopic Discectomy With Novel Lumbar Location System: Preliminary Report of Prospective Hello Study

AbstractProspective nonrandomized control study.The study aimed to investigate the implication of the HEs Lumbar LOcation (HELLO) system in improving the puncture accuracy and reducing fluoroscopy in percutaneous transforaminal endoscopic discectomy (PTED).Percutaneous transforaminal endoscopic discectomy is one of the most popular minimally invasive spine surgeries that heavily depend on repeated fluoroscopy. Increased fluoroscopy will induce higher radiation exposure to surgeons and patients. Accurate puncture in PTED can be achieved by accurate preoperative location and definite trajectory.The HELLO system mainly consists of self-made surface locator and puncture-assisted device. The surface locator was used to identify the exact puncture target and the puncture-assisted device was used to optimize the puncture trajectory. Patients who had single L4/5 or L5/S1 lumbar intervertebral disc herniation and underwent PTED were included the study. Patients receiving the HELLO system were assigned in Group A, and those taking conventional method were assigned in Group B. Study primary endpoint was puncture times and fluoroscopic time, and the secondary endpoint was location time and operation time.A total of 62 patients who received PTED were included in this study. The average age was 45.35 ± 8.70 years in Group A and 46.61 ± 7.84 years in Group B (P = 0.552). There were no significant differences in gender, body mass index, conservative time, and surgical segment between the 2 groups (P > 0.05). The puncture time(s) were 1.19 ± 0.48 in Group A and 6.03 ± 1.87 in Group B (P < 0.001). The fluoroscopic times were 14.03 ± 2.54 in Group A and 25.19 ± 4.28 in Group B (P < 0.001). The preoperative location time was 4.67 ± 1.41 minutes in Group A and 6.98 ± 0.94 minutes in Group B (P < 0.001). The operation time was 79.42 ± 10.15 minutes in Group A and 89.65 ± 14.06 minutes in Group B (P = 0.002). The hospital stay was 2.77 ± 0.95 days in Group A and 2.87 ± 1.02 days in Group B (P = 0.702). There were no significant differences in the complication rate between the 2 groups (P = 0.386).The highlight of HELLO system is accurate preoperative location and definite trajectory. This preliminary report indicated that the HELLO system significantly improves the puncture accuracy of PTED and reduces the fluoroscopic time, preoperative location time, as well as operation time. (ChiCTR-ICR-15006730)

Radiographic Analysis of One-level Minimally Invasive Transforaminal Lumbar Interbody Fusion (MI-TLIF) With Unilateral Pedicle Screw Fixation for Lumbar Degenerative Diseases.

Study Design: A prospective randomized study was conducted. Objective: The purpose of this study was to assess the radiographic outcomes of one-level minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) with unilateral pedicle screw instrumentation for degenerative lumbar spine disease. Summary of Background Data: MI-TLIF has become an increasingly popular method of lumbar arthrodesis. Recent technological advances in spinal instrumentation have culminated in the development of MI-TLIF with unilateral pedicle screw fixation. However, there are few published studies on radiographic outcomes of the MI-TLIF with unilateral pedicle screw fixation. Methods: A total of 65 patients with one-level degenerative lumbar spine disease were enrolled in this study. Patients were randomized into the unilateral or bilateral fixation group based on a computer-generated number list. Thirty-one patients (17 men and 14 women; average age, 57.3 y) were randomized to the unilateral group (group A) and 34 patients (16 men and 18 women; average age, 58.9 y) to the bilateral group (group B). All patients underwent minimally invasive decompression, interbody fusion, and pedicle screw fixation with the assistance of microscopic tubular retractor system (METRx-MD) and Sextant system. All patients were asked to follow-up at 3, 6, and thereafter once every 6 months after surgery. The visual analog scale (VAS), Oswestry disability index (ODI), and modified Prolo (mProlo) scores were obtained for all patients 24 hours before the operation and at each follow-up visit. The whole lumbar lordosis (WL), the segmental lordosis (SL), fusion level disk space angle, lumbar scoliosis angle, and segmental scoliosis angle were determined before and after surgery on standard x-rays. The disk height index (DI) and the lumber curvature index (LI) were also evaluated. Results: The mean follow-up was 26.6 months, with a range of 18–36 months. All patients showed evidence of fusion at 12 months postoperatively. Statistically, there was no significant difference between the 2 groups in terms of demographic data. The average postoperative VAS, ODI, and mProlo scores improved significantly in each group. No significant differences were found between the 2 groups in relation to VAS, ODI, and mProlo scores at each follow-up time point. There were no significant differences between the 2 groups in relation to WL, SL, disk space angle, lumbar scoliosis angle, segmental scoliosis angle, DI, and LI. There was also no difference between postoperative different follow-up visits in terms of these radiographic parameters in both groups. There was a positive linear correlation between the LI and WL in both groups. Conclusions: One-level unilateral pedicle screw instrumented MI-TLIF provided similar radiologic and clinical outcomes to bilateral pedicle screw instrumented MI-TLIF. This study showed that MIS-TLIF with unilateral pedicle screw fixation would be sufficient in the management of preoperatively stable patients with lumbar degenerative disease.

Percutaneous Pedicle Screw Placement in the Lumbar Spine: A Comparison Study Between the Novel Guidance System and the Conventional Fluoroscopy Method.

Study Design: The clinical study was conducted on 145 patients who received either a novel guidance method or a conventional fluoroscopic method for the percutaneous pedicle screw placement in the lumbar spine. Objective: The aim of this study was to introduce a novel guidance method for percutaneous pedicle screw placement and to compare it with the conventional fluoroscopic method. Summary of Background Data: Conventional fluoroscopic method was associated with a long screw placement and a more fluoroscopy time. The novel guidance system effectively minimized the insertion and the radiation exposure times. Methods: A total of 145 patients were divided into 2 groups. A total of 65 patients (group A) underwent 152 percutaneous pedicle screw fixation by conventional fluoroscopic method. A total of 80 patients (group B) underwent 185 percutaneous pedicle screw fixation by a novel guidance method. Age, body mass index, and sex ratio were comparable between the 2 groups (P>0.05). The time of insertion, radiation exposure, and accuracy of the screw placement between the 2 groups were compared. Results: The mean time for a single pedicle screw placement was found to be 15.11±3.32 minutes in group A and 10.35±2.82 minutes in group B, respectively. The average radiation exposure was 9.06±2.15 s in group B and 13.07±3.06 s in group A, respectively. The differences were statistically significant for both screw placement and radiation exposure times (P<0.05). A total of 131 screws (86.2%) in group A and 163 screws (88.1%) in group B were perfectly located within the pedicle. The statistical difference was not significant (&khgr;2=0.277, P=0.598). Conclusions: The novel guidance system significantly reduced the insertion time and radiation exposure, provided the screw placement was accurately performed when compared with the conventional method.

Morphometric analysis of the working zone for posterolateral endoscopic lumbar discectomy based on magnetic resonance neurography.

Study Design: A magnetic resonance neurography (MRN)-based morphometric analysis of the working zone for posterolateral endoscopic lumbar discectomy (PELD) procedures on 32 health volunteers. Objective: The purpose is to utilize MRN as a noninvasive evaluation of the Kambin’s working zone, and further to analyze operative safety of the PELD procedures. Summary of Background Data: Intraoperative nerve root injuries of PELD procedures occur relative to the Kambin’s triangular working zone, which has been described previously based on formalin-fixed cadaver studies. However, the investigation in living individuals is not known. Thus, it is necessary to evaluate the dimensions of the working zone on both coronal and sagittal plane by radiologic assessments. Materials and Methods: MRN images of 32 health volunteers (average age 26.8 y; 18 men, 14 women) were analyzed from L1–L2 to L5–S1. On the coronal plane, we measured the distance from the superior endplate to the nerve root exiting from the dura (distance a), the distance from lateral aspect of the dura to the medial aspect of the nerve root along the superior endplate (distance b), and the angle between the nerve root and plane of the corresponding disk (angle &agr;). On the transversal plane, the vertical distance from the upper facet surface to the exiting nerve root at the lower/upper disk margin level (distance c/d) was also measured. Results: On the coronal plane, distance a was 16.69±5.07 mm (range, 6.60–26.10 mm), distance b was 13.64±2.52 mm (range, 9.30–21.20 mm), angle &agr; was 55.45±7.14 degrees (range, 40.00–73.00 degrees). Distance c on the transversal plane was 5.01±2.66 mm (range, 1.30–13.10 mm) and distance d was 1.99±1.26 mm (range, 0.70–7.80 mm). All these measurements increased as the spine level went down. Conclusions: The study indicated that MRN was a feasible noninvasive tool to evaluate the anatomic dimensions in the Kambin’s working zone. Before PELD, radiologic measurements of this working zone were recommended to perform a safer procedure.

Patient-reported and radiographic outcomes of minimally invasive transforaminal lumbar interbody fusion for degenerative spondylolisthesis with or without reduction: A comparative study.

This retrospective study aimed to compare the patient-reported outcomes and radiographic assessment of minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) for degenerative spondylolisthesis with reduction versus in situ fusion. Patients receiving MI-TLIF with reduction were assigned as Group A, and those without reduction were assigned as Group B. Radiographic fusion was assessed using Bridwells grading criteria. Preoperative and postoperative patient-reported outcomes including visual analogue score (VAS), Oswestry Disability Index (ODI), Japanese Orthopedic Association (JOA) scale and improvement rate were analyzed. There were 41 patients in Group A and 37 patients in Group B. The mean follow-up was 30.78±14.15months in Group A and 28.95±10.75months in Group B (p=0.525). There were no significant differences in hospital stay (p=0.261), estimated blood loss (p=0.639), blood transfusion (p=0.336), operation time (p=0.762) and complications (p=1.00) between the two groups. Radiographic fusion rate was 92.68% (38/41) in Group A, and 81.08% (30/37) in Group B (p=0.110). Significant differences were observed in either 3-month or last follow-up JOA, VAS, and ODI compared with preoperative JOA, VAS, and ODI, respectively (p<0.05). However, there were no significant differences in JOA, VAS, and ODI between the two groups whenever preoperatively, or 3-month postoperatively, or at the last follow-up (p>0.05). According to MacNab criteria, the excellent and good rate was 85.37% in Group A and 86.49% in Group B (p=0.983). MI-TLIF is an effective and satisfactory surgical technique to manage degenerative spondylolisthesis regardless of reduction or not, so routine reduction may not be a requirement in MI-TLIF for degenerative spondylolisthesis.

Gender difference in mobile phone use and the impact of digital device exposure on neck posture

Abstract This cross-sectional study aimed to identify gender differences in the cervical postures when young adults were using mobile phones, as well as the correlations between the postures and the digital devices use (computer and mobile phone). Questionnaires regarding the habits of computer and mobile phone use were administrated to 429 subjects aged from 17 to 33 years old (19.75 ± 2.58 years old). Subjects were instructed to stand habitually and use a mobile phone as in daily life; the sagittal head and cervical postures were measured by head flexion, neck flexion angle and gaze angle. Male participants had a significantly larger head flexion angle (96.41° ± 12.23° vs. 93.57° ± 12.62°, p  =  0.018) and neck flexion angle (51.92°  ±  9.55° vs. 47.09° ± 9.45°, p  <  0.001) than females. There were significant differences in head (F  =  3.62, p  =  0.014) and neck flexion (F  =  3.99, p  =  0.009) between different amounts of computer use. Practitioner Summary: We investigated possible gender differences in head and neck postures of young adults using mobile phones, as well as the potential correlations between these postures and digital device use. We found that males displayed larger head and neck flexion angles than females, which were associated with the amount of computer use.