Optimal iliac screw position in relation to the sciatic notch remains unknown. In 12 cadavers undergoing S2 alar-iliac (S2AI) screw placement, we tested the pullout strength of screws placed in ...proximity to the sciatic notch (≤5 mm) vs farther away from the sciatic notch (>5 mm).
A biomechanical, cadaver-based study was performed on 12 cadavers undergoing bilateral S2AI screw insertion. The position of the S2AI screw regarding the sciatic notch was dichotomized as ≤5 mm from the sciatic notch on the right side and >5 mm on the left side, confirmed using c-arm fluoroscopy. The primary outcome was the pullout strength of the screw (N). Secondary outcomes were stiffness (N/mm), yield force (N), and work to failure (N mm). Ischial tuberosity was embedded into polymethyl methacrylate and secured to a custom 3-axis vise grip mounted to a 14.5-kN load cell. Pullout testing was performed at 5 mm/min. Force and displacement data were collected at 100 Hz and evaluated using MATLAB. The Mann-Whitney test was performed.
Of 24 S2AI screws, 3 screws could not be tested because of cement-bone interface failure. A positive though nonsignificant trend of screw pullout strength was found for screws close to the notch compared with those farther from the notch (861.8 ± 340.7 vs 778.7 ± 350.8 N, P = .859). Similarly, screws close to the notch demonstrated a higher trend of stiffness (149.4 ± 145.4 vs 111.34 ± 128.2 N/mm, P = .320) and force to yield (806.9 ± 352.0 vs 618.6 ± 342.9 N, P = .455). Conversely, screws farther from the notch had a higher but similarly nonsignificant area under the force-displacement curve (10 867.0 ± 9565.0 vs 14 196.6 ± 9578.3 N mm, P = .455), which might be due to excess sheer/translation force that could not be reliably quantified.
Although placing S2AI screws ≤5 mm of the sciatic notch provided stronger fixation in 3 of 4 biomechanical testing categories, these results were not statistically significant. Therefore, placing S2AI screws ≤5 mm of the sciatic notch did not provide stronger fixation.
Abstract
INTRODUCTION:
As many as 30% of spinal cord stimulation (SCS) patients fail to obtain long-term pain coverage, even with the strictest parameters of a successful trial, unremarkable ...psychological assessment, and ideal placement of the permanent device. Why these patients either never receive adequate benefit or lose benefit remains elusive.
METHODS:
We performed a retrospective review of our prospective database of SCS patients undergoing surgery for routine indications. Six-month postoperative follow-up data were available for 45 patients. A score for global impression of outcome (1-10, with 10 being the best) was given by 2 reviewers who saw the patients preoperatively and throughout follow-up. Their scores were blinded from one another. A score of 5 was conservatively chosen as a success. The impact of Body Mass Index (BMI), random drug screen results, workers' compensation status, depression, and smoking were assessed.
RESULTS:
We report a phi correlation of 0.350 between smoking and failure (P = .019). Further, there is a trend of correlation (phi = 0.286) between drug use and patients (n = 3) who underwent device removal (P = .055). In this cohort, worker's compensation status, BMI, and depression did not impact outcome.
CONCLUSION:
Tobacco use correlates with less success with SCS at 6-month follow-up. Whether that is because of issues with healing and our transmission of signals to the periphery warrants further exploration. These data provide further evidence that tobacco cessation is important to surgical results.
Abstract
INTRODUCTION:
Recent advancements in technology allow for additional modulation of spinal cord stimulation (SCS). Examples include application of algorithms for increasingly precise ...stimulation points and incorporation of accelerometers to automatically adjust parameters based on body position. The literature contains little evidence on the value of SCS devices with advanced programming capabilities. We present a prospective study of patients undergoing SCS and compare outcomes of those with standard devices to those with advanced capabilities.
METHODS:
Thirty-seven patients underwent SCS placement for standard indications. Of these patients, 19 received devices with standard capabilities and 18 received devices with advanced capabilities. Group assignment was based on trial device by outside providers. Outcomes were tracked through serial administration of the Visual Analog Scale (VAS) and analysis was performed using independent samples t tests. Prior to surgery both groups were equivalent in terms of average VAS scores.
RESULTS:
Reductions in average VAS scores were observed in both groups: 6.63 ± 0.37 to 5.32 ± 0.49 for the standard group and 6.69 ± 0.42 to 3.53 ± 0.69 for the advanced group (Figure 1). A significant difference between the groups was found for average VAS scores at most recent follow-up (P = .042). Additionally, the mean reduction in VAS scores (delta VAS) was 1.32 ± 0.55 for the standard group and 3.17 ± 0.70 for the advanced group (P = .046) (Figure 2).
CONCLUSION:
Our data suggest that patients receiving SCS devices with advanced programming capabilities experience greater reductions in pain levels at short-term follow-up than those receiving SCS devices with standard capabilities. We will continue to track these patients in the long-term and assess impact of these devices on quality of life, disability, and psychological status.
Cardiac Surgery and Ischemic Optic Neuropathy Roth, Steven; Raphael, Jacob
Journal of cardiothoracic and vascular anesthesia,
January 2021, 2021-01-00, 20210101, Letnik:
35, Številka:
1
Journal Article
A rare and unusual class of tripyrrolic compounds, violet-colored tripyrrin-1,14-diones, can be prepared easily and in moderately high yields from base (piperidine)-catalyzed condensation of ...3-pyrrolin-2-ones with 2,5-diformylpyrroles. Dipyrrinones adopt the all-
syn-
Z conformation leading to helical, lock-washer like structures, which form dimers that are held together by intermolecular hydrogen bonds in nonpolar solvents and in the crystal. Strong bathochromic spectral shifts of the tripyrrindione ∼480
nm long wavelength UV–visible absorption band are seen with added base: DBU, 615
nm; TFA, 573
nm; and Zn(OAc)
2, 586
nm.
Tripyrrindiones, a rare class of violet-colored tripyrrolic compounds, can be prepared from 3-pyrrolin-2-ones and pyrrole-2,5-dialdehydes and form intermolecularly hydrogen-bonded dimers in CDCl
3 and in the crystal.
Display omitted
Abstract
INTRODUCTION:
With rising health care costs, clinical outcome data are becoming increasingly important. The concept of minimally clinical important difference (MCID) has been shown to be ...effective in spine surgery to differentiate between clinically insignificant and significant improvements and to measure the patient's perspective of quality of life and disability. We sought to determine the MCID for spinal cord stimulation (SCS) therapy for failed neck and back syndromes, which has not been established to date.
METHODS:
Preoperative and 6-month outcomes were assessed prospectively, including the Oswestry Disability Index (ODI), Beck Depression Inventory (BDI), and Visual Analogue Scale (VAS) questionnaires. Patients were asked by a blinded investigator: (1) are they satisfied with SCS therapy and (2) would they have the surgery again? Four methods of calculating the MCID were used, including the average change approach, the minimum detectable change approach, the change difference, and the receiver operating characteristic approach.
RESULTS:
Forty-eight patients who underwent SCS placement from 2012 to 2014 were prospectively reviewed. Thirty-five (73%) patients stated they were satisfied with SCS therapy and they would have the surgery again. Satisfied patients had an average improvement of 2.9 points on the VAS and 11.5 points on the ODI at 6 months compared with an average decline of 0.78 points on the VAS and 1.8 points on ODI in the patients who were not satisfied with SCS therapy (P = .005, P = .06). The 4 calculation methods yielded a range of outcome scores (ODI 8.2-13.3, BDI 3.2-7, McGill 0.3-1.3, and VAS 1.2-3.7).
CONCLUSION:
The MCID for SCS placement was calculated by using 4 methods. The results are similar to calculations for the MCID for traditional surgical procedures done for pain. Our results suggest that an improvement of 1.2 to 3.7 points on the VAS scale and 8.2 to 13.3 points on the ODI is clinically meaningful to the patient. Further defining the MCID for SCS therapy will remain of utmost importance in order to justify the cost of the procedure.
Radiofrequency ablation of superficial and perforator veins for venous insufficiency has emerged as a leading alternative to traditional vein stripping operations. This percutaneous technique can be ...performed in less than an hour using local anesthetic or sedation. The VNUS Closure catheters (VNUS Medical Technologies, San Jose, California) work by resistive heating in the vein wall that is constantly monitored through a feedback loop to the VNUS Closure generator. Side effects are less than with other endovenous ablation techniques and patients resume normal activity immediately. The new ClosureFAST catheter is an important advancement that combines the speed of endovenous laser ablation with the expected fewer side effects of radiofrequency ablation.
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