Journal of Spine

Study Design: Observational study.
Objective: Understanding the associated factors with lower back pain (LBP) and implementing effective prevention strategies are crucial. If the modifiable associated risk factors are uncovered in working generations, potential saving costs for workers’ care systems and society overall are highly anticipated. The purpose of the current cross-sectional survey is to identify a prevalence of present LBP of employed workers and to analyze modifiable risk factors associated with LBP in Japan.
Methods: One thousand four hundred and four employees were enrolled. Age, gender, body height and weight, work demands, smoking, alcohol intake, depressive mood (MCS/SF-36v2 less than 35), regular exercise and so forth were ascertained by a self-administration questionnaire. Associations between Pw-LBP (LBP for the present week) and these items were statistically evaluated (P<0.05=significant).
Results: The overall prevalence of Pw-LBP was 27.6%. The mean age, body weight, and BMI were significantly higher in the participants with Pw-LBP than without Pw-LBP. MCS/SF-36v2 was significantly lower in the participants with Pw-LBP than without Pw-LBP. In light and/or moderate work demands, and alcohol intake, the percentage of the participants with Pw-LBP was significantly higher than that without Pw-LBP. Alcohol intake had a statistically significant association with Pw-LBP.
Conclusion: In Japanese employed workers, the prevalence of Pw-LBP was 27.6%. The findings disclosed that alcohol intake was a risk factor of Pw-LBP of employed workers in Japan.

Introduction: The ideal material for the manufacture of cervical fusion cages used in anterior cervical discectomy and fusion (ACDF) is undetermined. Spacers made of polyether-ether-ketone (PEEK) are commonly used, although metal and ceramic devices are also commercially available. This observational study compared outcomes of ACDF using two different biomaterial spacers (i.e., PEEK and silicon nitride, Si3N4).
Methods: Twenty consecutive patients who underwent ACDF with Si3N4 were retrospectively compared to a group previously implanted with PEEK spacers. Patient demographics, neck pain visual analog scale (VAS) and the neck disability index (NDI) scores were recorded for all enrollees. Cervical radiographs, including flexion-extension views, were examined to determine fusion at 3, 6, 12, 24, and 36 months post-operatively.
Results: Patient demographics were essentially identical between groups, except for a slightly higher incidence of worker compensation claims in the PEEK group (p=0.27), and increased prevalence of cervical myelopathy in the Si3N4 group (p=0.12). There were no differences in the number of cervical levels treated (p=0.65) or hospital length of stay (p=0.65). No cage failures or infections occurred in either group. At 3, 6, and 12 months, the average flexionextension angular rotation was lower for the Si3N4 group as compared to the PEEK cohort. However, these data were not statistically significant. Nevertheless, the incidence of fusion was consistently higher in the Si3N4 group at all follow-up visits except 36 months; both groups reached 100% fusion at the 3-year time-point.
Conclusion: By 36 months, there were no differences in ACDF with PEEK or Si3N4 as measured by NDI, VAS, and radiographic fusion of cervical segments. Earlier time points suggested a trend toward enhanced fusion with Si3N4. The interim differences may reflect the enhanced bioactive surface of the silicon nitride spacers and/or the radiographic characteristics of each biomaterial.

Spontaneous Intracranial Hypotension (SIH) is a syndrome characterized with reduction of amount and pressure of Cerebro Spinal Fluid (CSF) due to leakage. Orthostatic headache is the most significant symptom. Central nervous system pressure below 60 mmH2O is ordinary.
Primary CSF leakage and dural rupture develops spontaneously or following minor trauma, coughing, sneezing, straining and stretching.
We present a 51-year-old female case with sacral lipoid meningocel. She had chronic headache and constipation for years and we estimated that CSF leakage developed due to strain. The symptoms regressed following the excision of meningosel pouch.

Background: Several surgical procedures have been recommended for the management of thoracic and lumbar fractures. Nowadays Mini- Open Anterior Fusion is reported to be a safe and effective alternative treatment for various spinal pathologies.
Aim: The aim of this study is to report the outcome of 138 cases who underwent mini open thoraco-lumbar surgery for thoracic and lumbar fractures.
Material and Methods: We performed a non-randomized retrospective analysis of the clinical outcome of 138 patients with 140 fractures who underwent mini open thoraco-lumbotomy surgery, between 2011 and 2016. Follow up periods were 6th weeks, 3rd and 6th months and also 1 year postoperatively. All the patients were operated with mini open thoraco/lumbotomy system (Syn-Frame). All of our patients with fractures, undervent posterior pedicle screw fixation prior to the anterior fusion just after the posterior fusion or a couple of days later (mean: 4.2; 2 to 7 days), depending on the general condition of patients. Thorax drainage was placed to all thoracotomy patients (63% to 87%).
Results: Fractures of 13 cases were due to tumor metastasis, and the rest of them were due to acute fractures, spondylodiscitis. 87 cases had thoracic (T6-T12) and 51 cases had lumbar (L1-L5) fractures. Discussion: Several methods are being used in order to achieve safe, and minimaly invasive approach in cases with thoracolumbar pathologies. The complication rates of this procedure are similar to endoscopy assisted thoracotomy. Syn-Frame System allows the opportunity to perform even 2-3 levels corpectomy and stabilization through a 5 cm skin incision. It is possible to insert 4 or more retractors from all angles to form an area just over the level operation level, without dealing with aorta, lung, urethra or heart.
Conclusion: We can estimate that this approach is safe, minimally invasive and effective besides reducing the pain and morbidity of conventional methods.

Possessing an odontoid process and unique superior articular facets, the axis vertebra morphometry significantly differs from morphometry of other cervical vertebrae. The fractures of axis, especially its dens, are very common and surgeries highly risky. Knowledge of the axis dimensions is essential not only for preclinical studies, diagnosis of spinal cord diseases, planning of the surgeries but also for correct selection and insertion of surgical instruments or vertebral implants design. Many quantitative studies of the second cervical vertebra have been performed, yet still lacking the area parameters determination and precision of three-dimension in vivo measurement. Vertebral dimensions are reported to vary among populations, although there are very little studies examining Caucasian specimen.

This study aims to provide three-dimensional in vivo morphometric analysis of the axis vertebra as well as comparison to the previous studies. The clinically relevant vertebral dimensions were measured on the threedimensional model reconstruction of CT scans providing high accuracy. Five human second cervical vertebrae were investigated (Caucasian males) and linear, area and angular dimensions were measured.

The data on vertebral body dimensions were best fitting Doherty and Naderi measurement. The vertebra body anterior height was established to be 26.2 mm and the posterior height 21.4 mm. The dens parameters were similar to those presented by Doherty. Doherty also reported large variation in the dens sagittal angle which was observed in the present study as well. The dens height was determined to be 17.8 mm which is significantly greater compared to the previous studies. The smallest height among specimens was reported to be 17.0 mm. The smallest anteroposterior or transverse diameter of the dens measured was the upper depth, 9.4 mm. The smallest and biggest areas of dens were measured to be 79.0 mm2 and 121.6 mm2. The superior articular facet area with mean value 211.2 mm2 was observed to be significantly bigger than the inferior area, 141.2 mm2. The mean sagittal angle of the inferior facet area was assessed to be 42.1° and the mean frontal angle of the superior articular facet 69.3°. The parameters of articular facets measured by Xu correspond to the present study. Due to the vertebral body enlargement in the inferior part of vertebra, the spinal canal superior depth,18.0 mm, was observed to be bigger than its inferior depth, 16.2 mm. In case of the spinal canal depth, Sengul measured values considerably greater than other studies. However, Singla, Gosavi and Xu presented the parameters very similar to the present study. Spinal canal width was measured to be 24.4 mm supporting the measurement done by Sengul which is 24.7 mm.

The measured vertebral dimensions can be used either for development of instrumentation, preclinical planning of surgeries, implant design or as the reference values for evaluation and diagnosis of various clinical conditions.

Background context: Synergy disc is a new cervical disc prosthesis that incorporates alignment restoration while providing full intervertebral disc kinematics.
Purpose: This follow-up study with 40 Synergy Disc patients with 24-month follow-up compared cervical alignment changes with a retrospective cohort of 30 single level anterior cervical discectomy and fusion (ACDF) patients.
Study design/setting: The pilot trial was a multi-center, prospective, consecutive patient enrollment study using the Synergy Disc for the treatment of single and two-level degenerative disc disease of the cervical spine.
Patient sample: The procedure was performed on 43 patients (45 implants) with follow-up on 40 patients (42 implants). For the historical cohort ACDF arm, 30 patients with similar follow-up with single level anterior discectomy, fusion and plating were used for segmental lordosis measurements.
Outcome measures: For the Synergy Disc group, the kinematic parameters included: range of motion (ROM), shell angle (SA), disc height (DH), sagittal plane translation and center of rotation (COR) in the X and Y direction. Standard assessments of clinical outcomes were also measured (Neck Disability Index, Visual Analog Scale). For the fusion arm, only functional spinal unit (FSU) angle was recorded using a single pre-operative and post-operative standing lateral cervical radiograph.
Methods: In the Synergy Disc group, static and dynamic radiological assessments were performed in 43 consecutive patients prior to the placement of the Synergy Disc. Forty patients were studied for the course of the study protocol (3 patients lost to follow-up). For the Synergy Disc group, all kinematic parameters were examined at a minimum of 24 months follow-up. Neck Disability Index and Visual Analog Scale for arm and neck pain were collected and analyzed. For the fusion group, standing lateral radiographs were reviewed.
Results: At a mean of 28 months with all patients having a minimum of 24-month follow-up (40 patients, 42 implants), the average SA of the Synergy Disc was maintained at 6 ± 2.7Ëš of lordosis. There was significant improvement in all clinical outcome measures. In the fusion group, with a similar follow-up period, there was a 4Ëš increase in lordosis of the FSU.
Conclusion: The Synergy Disc had an endplate angle of 6 ± 2.7Ëš at 2 years following surgery. This was comparable to the lordotic correction provided by an anterior cervical discectomy with interbody fusion and plating.

Objectives: To determine mid-term results and complications of a single center on magnetically controlled growing rod (MCGR) technique in Early Onset Scoliosis (EOS). Recently a number of preliminary reports about safety and effectiveness of MCGR have been published. We present a minimum of two years follow up of the MCGR treatment. All patients were treated in one center with the same protocol.

Methods: 22 patients with EOS of different etiologies underwent primary surgical treatment with MCGR in double rod technique. There were 15 female and 7 male patients. Average age at surgery was 8.8 (range 4.6-14.3). Mean follow-up was 31 (24-46) months. Cobb angle changes, T1-T12 and T1-S1 length were calculated. Results were analyzed to measure correction of spinal deformity and gain in spinal length.

Results: The mean preoperative curve measured 61° (40-96) and improved to 28° (11-53) (p<0.001) after surgery. At follow-up the Cobb angle was further reduced to 26° (11-64) (p=0.54). The T1-T12- as well as the T1-S1- length increased significantly (p<0.001). The average preoperative thoracic kyphosis decreased from 44° (-32-86) to 28° (9-50) after surgery, respectively to 35° (8-62) at time of FU. Four patients developed a junctional kyphosis. Three of them had to be revised. One patient developed a lumbar “adding on”, one patient a deep wound infection and in another patient a screw pullout occurred that all required revision.

Conclusion: The study supports that the MCGR is an efficient and safe technique to treat EOS. Morbidity and complications are less than treatment with conventional GR´s. After 2 years transcutaneous lengthening is still possible without loss of correction and autofusion has not yet been detected.

Study design: A retrospective clinical review.
Purpose: To explore the type, morbidity, risk factors and treatment strategies of postoperative complication following percutaneous endoscopic lumbar discectomy (PELD) surgery.
Overview of literature: PELD became one of the main operation methods for degenerative lumbar diseases, including disc herniation, stenosis and discogenic low back pain. However, complications following PELD surgery are a considerable challenge for spinal surgeons and seldom addressed publicly.
Methods: 10120 patients after PELD surgery were studied. These surgeries were finished by 6 surgeons from 3 main minimal invasive spine centers from January 2012 to June 2017. Most of patients are regularly followed up to explore the type, morbidity, risk factors and treatment strategies of postoperative complication following PELD surgery.
Results: There are 2 patients died in the perioperative period and 2 patients with permanent impairment of neural function after surgery, which should be the severest complication of PELD surgery. Transient paresthesia, intraoperative bleeding and dura sac tear are the most common complications reported by 6 surgeons. There are 2 suspected cases of postoperative hematoma, several cases of surgical instruments broken during the surgery and 20 cases of infection in 10120 patients, regarded as rare complications of PELD. Recurrence rate of PELD surgery is 4.7% to 6% reported by 3 surgeons. However, recurrence defined as complications of PELD surgery remain controversial.
Conclusion: Excellent clinical outcome of large case series after PELD surgery is reported. However, we need to face the limitations and complications of the surgery. The complication rate should be reduced by caring about the treatment, surgical indications strictly selected and the guidance of experienced surgeons.

Purpose: To elucidate the association between computed tomography (CT)/magnetic resonance imaging (MRI) and radiographic findings of fractured vertebral body instability in patients with osteoporotic vertebral fractures and to clarify whether resistance to conservative treatment can be evaluated on the basis of dynamic loading radiography.
Methods: Seventy-eight patients aged ≥ 65 years who underwent conservative treatment for osteoporotic single vertebral fractures of the thoracolumbar junction were divided into the conservative treatment-resistant group (18 patients) and control group (60 patients). We evaluated the accuracy of the prediction of resistance to conservative treatment on the basis of the CT/MRI findings and the difference in compression rates between standing and supine positions at the time of the first visit. The differences in compression rates (%) were compared between the two groups. In addition, a receiver operating characteristics (ROC) curve was drawn to evaluate the accuracy of the prediction of resistance to conservative treatment.
Results: In patients without (47 cases) and with CT findings (31 cases), the mean differences in compression rates (%) was 8.9% and 19.1%, respectively (p=0.0029). The mean differences in compression rates (%) of patients without (60 cases) and with MRI findings (18 cases) was 9.7% and 24.0%, respectively (p=0.0043). The mean differences in compression rates (%) in the conservative treatment-resistant group was 26.3%, while that in the control group was 9.0 (p=0.0066). In addition, according to the ROC curve of the difference in compression rate was 0.93 (95% confidence interval: 0.87–1), and when a 20% difference in compression rate was considered as the threshold value.
Conclusion: Dynamic loading radiography is useful for the evaluation of resistance to conservative treatment in patients with osteoporotic vertebral fractures, and that a compression rate difference of ≥ 20% predicts resistance to conservative treatment.