Incidence of sacroiliac joint pain after lumbosacral spine fusion: A systematic review.

OBJECTIVES: To determine the incidence of sacroiliac joint (SIJ) pain after lumbosacral spinal fusion. BACKGROUND: Persistent low back pain is a potential source of disability and poor outcomes following lumbar spine fusion. The SIJ has been described as a potential source. However, there is a paucity of data concerning its importance. METHODS: This is a PROSPERO registered systematic review. A systematic search of the English literature was performed in Medline, Embase and Cochrane Library databases. MeSH terms such as Lumbar vertebrae, Sacrum, Spinal Fusion, Pain, Sacrum, Ligaments, Sacroiliac Joint were utilized for the search. Key words such as "sacroiliac dysfunction.mp." and "sacroiliac complex.mp." were utilized for the search. Two independent reviewers reviewed articles to determine eligibility for final review and analysis. The Newcastle-Ottawa Scale was used to appraise the quality of all nonrandomized observational studies. Inverse variance weighting with random effects was used to pool data. The GRADE approach, PRISMA workflow and checklists was performed. RESULTS: Twelve studies were included. All studies were observational and of moderate to low quality. The pooled incidence of sacroiliac joint pain was 15.8%. The pooled incidence of SIJ pain for patients without fusion extending to the sacrum was 15.8%. The pooled incidence of SIJ pain for patients with fusion extending to the sacrum was 32.9%. There was high heterogeneity. CONCLUSION: SIJ pain is a potential cause of persistent pain after lumbar spine surgery. The current literature of poor quality. Patients presenting with pain after lumbosacral spine fusion should be evaluated for SIJ related pain.

Impact of obesity on complications and surgical outcomes of adult degenerative scoliosis with long-segment spinal fusion.

INTRODUCTION: The relationship between obesity and outcome of spine surgery has been controversial. The impact of obesity on surgical outcomes of patients undergoing long- segment (6 vertebrae or more) spinal fusion have not been studied. This study was designed to define the influence of obesity on the outcomes of patients undergoing long-segment spinal fusion. METHODS AND MATERIALS: A retrospective study of patients undergoing long-segment (6 vertebrae or more) spinal fusion was realized. Patients were divided into non-obese group and obese group. Variables such as blood loss, operative time, length of stay, complications, reoperation rates, and clinical outcome were compared between the two groups. RESULTS: Thirty-four non-obese patients (BMI: 26.43±0.87) and 27 obese ones (BMI: 35.35±1.81) were recruited. Number of fused levels in non-obese group was not significantly different from obese group (9.06±0.57 vertebrae vs 8.85±0.68 vertebrae, P=0.65). There was no significant difference between non-obese group and obese group in the blood loss during surgery (P= 0.12), the operating time (P=0.46) and the length of hospitalization (P=0.64). Similarly, no significant difference was found in surgical complications (P=0.76) and medical complications (P=0.82) between the two groups. The rate of ambulatory improvement is similar between non-obese group and obese group (P=0.64). CONCLUSION: Our study showed that there was no relationship between obesity and adverse surgical outcomes in ADS surgery with long-segment (6 vertebrae or more) spinal fusion.

Analysis of trimodal and bimodal therapy in a selective-surgery paradigm for locally advanced oesophageal squamous cell carcinoma.

BACKGROUND: Long-term survival outcomes of trimodal therapy (TMT; chemoradiation plus surgery) and bimodal therapy (BMT; chemoradiation) have seldom been analysed. In a selective-surgery paradigm, the benefit of TMT in patients with a complete clinical response is controversial. Factors associated with survival in patients with a clinical complete response to chemoradiation were evaluated. METHODS: Patients with stage II-III oesophageal squamous cell carcinoma treated with TMT or BMT from 2002 to 2017 were evaluated. The BMT group consisted of patients who were otherwise eligible for surgery but underwent chemoradiation alone followed by observation. This group included patients who later had salvage oesophagectomy. Survival was evaluated and compared between TMT and BMT groups. Elastic net regularization was performed to select co-variables for Cox multivariable survival analysis in patients with a clinical complete response. RESULTS: Of 143 patients, 60 (41.9 per cent) underwent TMT and 83 (58.0 per cent) BMT. Patients who underwent TMT had longer median overall survival than those who had BMT (77 versus 33 months; P = 0.019). For patients with a clinical complete response, TMT achieved longer median overall survival than BMT (123 versus 55 months; P = 0.04). BMT had a high locoregional recurrence rate (48 versus 6 per cent; P < 0.001); 26 of 29 patients with locoregional recurrence in the BMT groupunderwent salvage resection. Cox multivariable analysis demonstrated that upper-mid oesophageal tumour location (hazard ratio (HR) 2.04; P = 0.024) and tumour length (HR 1.18; P = 0.046) were associated with worse survival. Although TMT was not associated with survival, it was a predictor of reduced recurrence (HR 0.28; P = 0.028). The maximum standardized uptake value after chemoradiation also predicted recurrence (HR 1.33; P < 0.001). CONCLUSION: In patients who achieve a clinical complete response, TMT reduces locoregional recurrence but may not prolong survival. The differences in survival outcomes may be due to patient selection; therefore, a selective-surgery strategy in oesophageal squamous cell carcinoma is a reasonable approach.

C2-C3 vertebral disc angle: An analysis of patients with and without cervical spondylotic myelopathy.

STUDY DESIGN: Retrospective analysis. OBJECTIVE: To define C2-C3 vertebral disc angle (VDA) in patients with and without cervical spondylotic myelopathy. SUMMARY OF BACKGROUND DATA: C2-C3 VDA is a new radiological index of cervical spine alignment. Recent studies have suggested that high postoperative values are associated with greater mechanical complications in patients with cervical spondylotic myelopathy. However, normative values for patients without myelopathy has yet to be defined. METHODS: Patients with and without cervical myelopathy between 2017 and 2019 were included. Inclusion criteria were patients above 18 years of age with antero-posterior (AP) and lateral (LAT) cervical X-rays. In the non-myelopathic group, patients were excluded if they had neurological symptoms or deficits, presence of cervical axial pain, previous spinal surgery, or diagnosis of either spondylolisthesis or scoliosis. In the myelopathic group, patients were excluded if they had previous spinal surgery. Radiological indices evaluated include: C2-C3 disc angle, C2-C7 Cobb angle, C7 sagittal vertical axis, T1 slope. RESULTS: In total, 99 patients without myelopathy and 22 patients with myelopathy were identified and analyzed. In patients without myelopathy, the mean for C2-C3 VDA was 25.9±7.9. For patients with myelopathy, preoperative values were 24.4±10.0 and 27.1±7.9 postoperatively. No statistically significant differences were found between patients with and without myelopathy. C2-C3 disc angle was not correlated with age (R=-0.173). CONCLUSION: This study did not find statistically significant differences in C2-C3 VDA values between patients with and without cervical myelopathy. This study provides normative data for C2-C3 vertebral disc angle in patients with and without cervical spondylotic myelopathy. Furthermore, C2-C3 vertebral disc angle may be independent from age.

One-stage oblique lateral corridor antibiotic-cement reconstruction for Candida spondylodiscitis in patients with major comorbidities: Preliminary experience.

Fungal spondylodiscitis is rare (0.5%-1.6% of spondylodiscitis) and mainly caused by Candida albicans. Surgical intervention in spondylodiscitis patients is indicated for compression of neural elements, spinal instability, severe kyphosis, failure of conservative management and intractable pain. However, there is no evidence-based optimal surgical approach for spondylodiscitis. There have been only case reports of surgical treatment for Candida spondylodiscitis. We evaluated the preliminary results of the efficacy and safety of one-stage debridement via oblique lateral corridor with interbody fusion (OLIF) using stand-alone cement reconstruction after debridement for the treatment of Candida spondylodiscitis in patients with major co-morbidities. Five patients (4 males, 1 female, mean age: 64.2 years) suffering from Candida albicans lumbar spondylodiscitis who underwent this procedure were studied. Their predominant symptoms were unremitting back and leg pain and all had pre and postoperative anti-fungal therapy under microbiologist supervision. The operative time ranged from 137minutes to 260minutes (mean: 213.4minutes). The mean blood loss was 160mL (range: 100-200mL). There were no perioperative complications. At follow-up all showed major improvement in pain and ambulatory status. CT scan showed radiological stability for all patients at 6-12 months. Our preliminary results showed stand-alone anterior debridement and spinal re-construction with cement through mini-open OLIF approach might be a safe and effective option for patients with spinal fungal infection and major comorbidities.

Customized vs population-based growth charts to identify neonates at risk of adverse outcome: systematic review and Bayesian meta-analysis of observational studies.

OBJECTIVE: To compare the effectiveness of customized vs population-based growth charts for the prediction of adverse pregnancy outcomes. METHODS: MEDLINE, ClinicalTrials.gov and The Cochrane Library were searched up to 31 May 2016 to identify interventional and observational studies comparing adverse outcomes among large- (LGA) and small- (SGA) for-gestational-age neonates, when classified according to customized vs population-based growth charts. Perinatal mortality and admission to the neonatal intensive care unit (NICU) of both SGA and LGA neonates, intrauterine fetal demise (IUFD) and neonatal mortality of SGA neonates, and neonatal shoulder dystocia and hypoglycemia as well as maternal third- and fourth-degree perineal lacerations in LGA pregnancies were evaluated. RESULTS: The electronic search identified 237 records that were examined based on title and abstract, of which 27 full-text articles were examined for eligibility. After excluding seven articles, 20 observational studies were included in a Bayesian meta-analysis. Neonates classified as SGA according to customized growth charts had higher risks of IUFD (odds ratio (OR), 7.8 (95% CI, 4.2-12.3)), neonatal death (OR, 3.5 (95% CI, 1.1-8.0)), perinatal death (OR, 5.8 (95% CI, 3.8-7.8)) and NICU admission (OR, 3.6 (95% CI, 2.0-5.5)) than did non-SGA cases. Neonates classified as SGA according to population-based growth charts also had increased risk for adverse outcomes, albeit the point estimates of the pooled ORs were smaller: IUFD (OR, 3.3 (95% CI, 1.9-5.0)), neonatal death (OR, 2.9 (95% CI, 1.2-4.5)), perinatal death (OR, 4.0 (95% CI, 2.8-5.1)) and NICU admission (OR, 2.4 (95% CI, 1.7-3.2)). For LGA vs non-LGA, there were no differences in pooled ORs for perinatal death, NICU admission, hypoglycemia and maternal third- and fourth-degree perineal lacerations when classified according to either the customized or the population-based approach. In contrast, both approaches indicated that LGA neonates are at increased risk for shoulder dystocia than are non-LGA ones (OR, 7.4 (95% CI, 4.9-9.8) using customized charts; OR, 8.0 (95% CI, 5.3-10.1) using population-based charts). CONCLUSIONS: Both customized and population-based growth charts can identify SGA neonates at risk for adverse outcomes. Although the point estimates of the pooled ORs may differ for some outcomes, the overlapping CIs and lack of direct comparisons prevent conclusions from being drawn on the superiority of one method. Future clinical trials should compare directly the two approaches in the management of fetuses of abnormal size. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

A modified blade element theory for estimation of forces generated by a beetle-mimicking flapping wing system.

We present an unsteady blade element theory (BET) model to estimate the aerodynamic forces produced by a freely flying beetle and a beetle-mimicking flapping wing system. Added mass and rotational forces are included to accommodate the unsteady force. In addition to the aerodynamic forces needed to accurately estimate the time history of the forces, the inertial forces of the wings are also calculated. All of the force components are considered based on the full three-dimensional (3D) motion of the wing. The result obtained by the present BET model is validated with the data which were presented in a reference paper. The difference between the averages of the estimated forces (lift and drag) and the measured forces in the reference is about 5.7%. The BET model is also used to estimate the force produced by a freely flying beetle and a beetle-mimicking flapping wing system. The wing kinematics used in the BET calculation of a real beetle and the flapping wing system are captured using high-speed cameras. The results show that the average estimated vertical force of the beetle is reasonably close to the weight of the beetle, and the average estimated thrust of the beetle-mimicking flapping wing system is in good agreement with the measured value. Our results show that the unsteady lift and drag coefficients measured by Dickinson et al are still useful for relatively higher Reynolds number cases, and the proposed BET can be a good way to estimate the force produced by a flapping wing system.

Clinical evaluation of six composite resins in posterior teeth.

Six different composite resin restorative materials were placed in posterior Class I and Class II cavities and evaluated at one and two years after placement for colour, marginal discoloration, and wear. Wear was determined by comparison with standard models and by SEM. All materials darkened over the study period but remained an acceptable match. Marginal discoloration increased. The trend of relative wear was in accordance with predictions from fracture mechanics. Insufficient restorations in one material were available at two years for it to be included in the results. The microfine materials used in this study suffered surface damage (micro-chipping) in high stress areas, again consistent with fracture mechanics predictions.

Definitions for hydration changes of hydrogel lenses.

Authors of studies on the hydration characteristics of hydrogel lenses have used a variety of definitions to describe the changes observed with exposure of the lenses to different environments. This has resulted in difficulties in the interpretation of published data. In particular, the single term "percentage dehydration" has been used to denote different mathematical expressions for alterations to the lens composition. A detailed theoretical analysis of hydrogel hydration levels is presented to examine definitions for lens hydration changes, compare results obtained under different definitions and propose appropriate usage for the alternative definitions according to the aspect of lens performance under consideration. The interrelationships between the commonly used definitions of dehydration are shown to be independent of initial lens mass but dependent on initial water content. Typically, higher water content lenses undergo considerably larger mass changes than lower water content lenses, an effect that may be masked if these changes are presented as changes of water content. There are a number of clinical consequences of lens dehydration, the importance of which will vary depending on the initial lens water content. It is therefore essential when comparing different water content lenses on the basis of the extent of dehydration to do so with respect to a specific clinical consequence rather than in general terms.