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Abstract: Background context: Noninvasive strength assessment techniques are the clinical standard in the diagnosis and treatment of osteoporotic vertebral fractures, and the efficacy of these protocols depends on their ability to predict vertebral strength at all at-risk spinal levels under multiple physiological loading conditions. Purpose: To assess differences in vertebral strength between loading modes and across spinal levels. Study design/setting: This study examined the relative strength of isolated vertebral bodies in compression versus flexion. Methods: Destructive biomechanical tests were conducted on 30 pairs of donor-matched, isolated thoracic vertebral bodies (T9 and T10; F=19, M=11; 87+5 years old, max=97 years old, min=80 years old) in both uniform axial compression and flexion using previously described protocols. Quantitative computed tomography (QCT) scans were taken before mechanical testing and used to obtain bone mineral density (BMD) and “mechanics of solids” (MOS) measures, such as axial and bending rigidities. Results: Compressive strength was higher than flexion strength for each donor by 940+152N (p<.001, paired t test), and vertebral strengths in the two loading modes were moderately correlated (adjusted R 2=0.50, p<.001). For both compression and flexion loading modes, adjacent-level BMD and MOS metrics had approximately half the predictive capacity as same-level measurements, and BMD and MOS values were only moderately correlated across spinal levels. Conclusions: The results of this study are important in designing clinical test protocols for assessing vertebral fracture risk. Because vertebral body flexion and compressive strength are not strongly correlated and flexion strength is significantly less than compressive strength, it is imperative to investigate a patient''s spinal structural capacity under bending loading conditions. Furthermore, our work suggests that clinicians using QCT-based measures should perform site-specific strength assessments on each at-risk spinal level. Future work should focus on improving the accuracy of densitometric measures in predicting vertebral strength in flexion and also on examining same- versus adjacent-level strength assessment for radiographic techniques with lower X-ray dosage, such as dual-energy X-ray absorptiometry. [Copyright &y& Elsevier]

BACKGROUND CONTEXT Controversy exists regarding whether fusion should be used to augment decompression surgery in patients with symptomatic lumbar spinal stenosis with grade I/II (low-grade), stable degenerative spondylolisthesis. For years, the standard has been fusion with laminectomy in order to prevent postoperative instability. However, instability and reoperations may be reduced or prevented using less invasive, structure sparing decompression techniques without the need for fusion. PURPOSE To compare reoperation rates within a 5-year follow-up period of unilateral laminotomy for bilateral decompression (ULBD) versus posterior lumbar decompression with instrumented fusion (fusion) for patients with degenerative spondylolisthesis with spinal stenosis in a multicenter database. STUDY DESIGN/SETTING Retrospective cohort study. PATIENT SAMPLE A final cohort of 601 Kaiser Permanente Northern California members with diagnoses of lumbar degenerative spondylolisthesis and lumbar spinal stenosis of whom 164 patients underwent ULBD and 437 underwent fusion between January 2007 and December 2011. OUTCOME MEASURES The primary outcome measure was reoperation rate at 5-year postoperative follow-up. Secondary outcome measures included blood loss during surgery, length of stay, reoperation type, reoperation level, and 90-day postoperative complication rates. METHODS We identified 164 patients with lumbar degenerative spondylolisthesis and lumbar stenosis who underwent ULBD between January 2007 and December 2011. These patients were propensity score matched on age at surgery, gender, race and smoking status with patients who underwent fusion (n=437). The primary outcome was 5-year reoperation rate and secondary outcome measures included postoperative complication rates, reoperation type, reoperation level, blood loss during surgery, and length of stay. RESULTS The reoperation rate within 5-year follow-up was significantly lower at 10.4% in the ULBD group compared to 17.2% in the fusion group (p=.0393). Type of reoperation was similar between the two groups. Reoperation at the index or adjacent level was not significant different between the two groups. Patients that underwent ULBD had significantly less mean estimated blood loss compared to fusion (82 vs. 445 ml, p<.0001) and significantly shorter mean length of stay (2.3 vs. 4.6 days, p<.0001). The two types of operations had similar postoperative complication rates, with less surgical site infections for ULBD compared with fusion (1 vs. 11 cases). There was no difference in the Charlson Comorbidity Index between the two groups. CONCLUSIONS For patients with stable degenerative spondylolisthesis and lumbar stenosis, ULBD is a viable, durable option compared to fusion with a lower reoperation rate within a 5-year follow-up period, as well as decreased blood loss and length of stay. Further prospective studies are required to determine the optimal clinical scenario for ULBD in the setting of degenerative spondylolisthesis. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs [ABSTRACT FROM AUTHOR]

Degenerative spondylolisthesis (DS) with lumbar spinal stenosis (LSS) is commonly treated with decompression and fusion. The LimiFlex Dynamic Sagittal Tether (DST) is an investigational stabilization device for patients with DS and LSS. The purpose of this study is to assess the clinical and radiographic outcomes of decompression and DST compared to transforaminal lumbar interbody fusion (TLIF) for patients with DS and LSS. Multicenter prospective concurrently controlled study. Patients undergoing treatment (decompression and DST or TLIF stabilization) of Grade I Meyerding lumbar degenerative spondylolisthesis. Patients undergoing treatment (decompression and DST or TLIF stabilization) of Grade I Meyerding lumbar degenerative spondylolisthesis. Patients with single-level Grade I DS with LSS were enrolled in the FDA-IDE study (NCT03115983) comparing decompression with DST and decompression with TLIF. Clinical and radiographic outcomes were assessed at baseline and 6-week, 3, 6, 12 and 24-month follow-up. All propensity score (PS) selected patients who had 24-month follow-up were included in this interim analysis. Summary statistics are reported, as well as paired t-tests to assess within-group changes. At 24 months, 228 PS-selected patients (129DST/99TLIF) had clinical follow-up and 197 (117DST/80TLIF) had radiographic follow-up. Mean characteristics of DST and TLIF groupswere: age 65.5/64.1 yrs; BMI 28.1/30.5; CCI 0.43/0.41, respectively. Mean perioperative outcomes for DST/TLIF were: procedure time 112/189 min; EBL 53/232 mL; LOS 0.7/3.2 nights. A significant reduction at 24 months for mean VAS-leg/hip (79.5 to 22.9), VAS-back (66.8 to 19.0) and ODI (52.8 to 13.2) was reported for DST patients (all p < 0.01) with 91% achieving 15-point ODI improvement. TLIF patients demonstrated similar improvements for VAS-leg (80.6 to 24.4), VAS-back (68.1 to 26.1) and ODI (52.3 to 20.9) (all p < 0.01), with 80% achieving 15-point ODI improvement. While there was no difference at baseline, the DST group had lower ODI at all postoperative timepoints. Within the 24 months, 9% of each group had additional surgery at the index or adjacent level. At 24 months, the DST group had mean reductions of 1.7° ROM and 0.4mm translation in flexion/extension images compared to 3.8° and 1.0mm reductions in the TLIF group. Considering the index and adjacent segments together (IAS), the index segment accounted for 30% of IAS ROM at baseline and 27% at 24 months in the DST group compared to 29% at baseline and 13% at 24 months in the TLIF group. These results suggest that decompression with DST stabilization for spondylolisthesis can achieve significant clinical improvement as is expected with fusion, without an increase in reoperations during the 24 months postoperative period. Similarly, statistically significant improvements in patient-reported outcomes were demonstrated in each group, with lower disability scores in the DTB group at all postoperative timepoints. Imaging demonstrated no increased instability in the DST group with maintained distribution of motion between the index and adjacent segments. While these groups were PS-selected, further analyses should include quantitative comparison between groups with PS-adjusted differences per the predefined composite clinical success criteria for a definitive comparison of outcomes. LimiFlex Dynamic Sagittal Tether (Investigational/Not Approved). [ABSTRACT FROM AUTHOR]

Degenerative spondylolisthesis (DS) with lumbar spinal stenosis (LSS) is commonly treated with decompression and fusion. The LimiFlex Dynamic Sagittal Tether (DST) is an investigational stabilization device for patients with DS and LSS. Assess return to work (RTW) and activities of daily living (ADL) receiving either decompression and DST stabilization (D+DST) or decompression and transforaminal lumbar interbody fusion (D+TLIF). Interim analysis from a multicenter, concurrently controlled study. Patients undergoing treatment (D+DST or D+TLIF) of Grade I Meyerding lumbar DS. Propensity score (PS) selected patients with 12-month follow-up were included. Time to RTW and activities of daily living, as well as Oswestry disability index (ODI). PS-selected IDE study subjects with 12 months of follow-up were included in this analysis. Study records queried for work status preoperatively and at 12 months, as well as time to RTW and ADL, and change in disability (Oswestry Disability Index; ODI) at 12 months vs preop. Outcomes were compared using student's t-tests. PS-selected subjects totaled 267 (136 D+DST, 131 D+TLIF). Preoperatively, 49% of D+DST and 43% of D+TLIF subjects were working (p=0.14) and 7% D+DST and 11% D+TLIF were not working due to spinal condition (NWSC) (p=0.13). At 12 months postop, 44% of D+DST and 34% of D+TLIF subjects were working (p=0.05) and 2% D+DST and 10% D+TLIF were NWSC (p<0.01). Proportion of D+DST NWSC was significantly lower 12 months postop compared to preop (p=0.02). Mean±SD RTW time for D+DST/D+TLIF subjects was 5.4±6.6/11.8±9.6 weeks (p<0.01) and return to ADL time was 5.5±6.5/10.0±9.5 weeks (p<0.01). Mean±SD reduction in disability at 12 months from baseline was 38.1±18.4 for the D+DST group and 31.8±20.7 for the D+TLIF group (p<0.01) with effect sizes of -2.1 and -1.5, respectively. The primary objective of surgery for symptomatic DS is resolution of symptoms so patients can return to their normal ADL and work. Both D+DST and D+TLIF treated patients demonstrated a significant reduction in disability at 12-month follow-up. Significantly faster RTW and ADL were observed for D+DST compared to D+TLIF patients, by an average of more than 5 weeks. The proportion of D+DST patients NWSC was significantly less than at 12 months. Results indicate a significant advantage of earlier recovery for the D+DST patients allowing earlier RTW and earlier increase in ADLs compared to D+TLIF, with similar or greater improvements in disability after one year for patients treated with decompression and stabilization for symptomatic DS. Longer-term follow-up assessment with propensity score-adjusted outcomes will demonstrate whether this advantage and long-term outcomes are durable and generalizable. This abstract does not discuss or include any applicable devices or drugs. [ABSTRACT FROM AUTHOR]

Fenestrated pedicle screw cement augmentation (FPSCA) in spine surgery has recently been FDA approved in 2016. Although numerous biomechanical studies support its use to increase pull-out strength, few studies report its safety and efficacy in a broad scope of indications. Our goal was to report our practice pattern, perioperative outcomes and complications with a new FPSCA system. Retrospective cohort study. Forty-three consecutive patients over 14 months. Occurrence of hardware failure, cement leaks, cement embolism, fat embolism, mortality Forty-three patients underwent FPSCA (2.5mL of high viscosity polymethylmetacrylate per screw) between September 2017 and November 2018 by six surgeons at our institution for degenerative disease, tumor, trauma or deformity correction. Baseline demographics, bone density, operative data, perioperative outcome (failure rate), complications (cement embolus, pulmonary embolism, perivertebral cement leaks, mortality) and postoperative X-rays or computed tomography were reported. Our practice pattern was also reported (regional distribution and indications). Average age was 64.9±17.6 years. Mean follow-up was 15.5±12.3 weeks. Twenty-three patients (53.5%) had osteoporosis or osteopenia; 175 cement-augmented pedicle screws were used in constructs totaling 276 screws (63.4%). Regional distribution was: thoracic (18%), lumbar (58.1%) and thoracolumbar (23.2%). Indication were: deformity (36.2%), tumor (24.9%), trauma (7%) and degenerative conditions (31.9%). Most augmentations were performed at a combination of the UIV, UIV –1 and LIV. Systematic verification of screw depth before injection prevented rod insertion difficulties. Complications comprised cement leakage (22 patients, 51.1%), hardware failure (4 patients, 9.3%) and non-cement related pulmonary embolism (two patients). Fifty-six leaks occurred and concerned segmental veins (38 leaks, 67.8%), basivertebral veins (8 leaks, 14.2%), a cortical defect (4 leaks, 9.3%) or the spinal canal (6 patients, 13.9%). None of the patients developed acute respiratory distress syndrome from fat embolism. No symptomatic cement embolism or perioperative cement-related death occurred. This is the largest mixed-indication case-series on record in North America. Fenestrated pedicle screw augmentation in spine surgery can be a safe and effective method of increasing fixation in osteopenic bone. This abstract does not discuss or include any applicable devices or drugs. [ABSTRACT FROM AUTHOR]

The United States is currently undergoing a major opioid crisis that has recently started to decrease its population's life expectancy due to over-mortality of its young citizens by drug overdose. Among the listed causes, physician narcotic prescriptions for both acute and chronic medical conditions are often pointed out as the main culprit for this crisis. We investigated the differences between discharge prescriptions following outpatient lumbar spine surgery between a French and a US spine surgery department. Multicenter comparative observational study. A total of 100 age and sex-matched patients: 50 patients in the American center, 50 in the French center. Amount of narcotics in MED (morphine equivalent dose) in the discharge prescription. Number of postoperative visits to the emergency room for inadequate pain control. Demographics, comorbidities, operative data, current prescriptions and discharge prescriptions were compared between the two groups. Narcotic consumption was converted in milligrams of morphine equivalent dose (mg MED). A total of 25 American patients (50%) consumed narcotics preoperatively vs 4 French patients (8%). Only 22% of Americans were opioid naïve. Postoperatively, all French patients had a narcotic-free prescription while all American patients were prescribed a significant amount of narcotics (617.04mg ± 345.16mg MED). One American patient returned to the emergency department for inadequate pain control while none of the French did. French patients were never prescribed steroids but had systematic nonsteroid inflammatory drugs while 41.4% of American patients were prescribed postoperative steroid tapers following a postoperative telephone call. For identical surgeries, all American patients were prescribed postoperative narcotics while none of the French were. Cultural beliefs from both patients, physicians and the industry probably represent the most significant barrier against the implementation of a narcotic-free culture in our practice. Reducing narcotic prescriptions in our practice is not only feasible but also highly desirable. This abstract does not discuss or include any applicable devices or drugs. [ABSTRACT FROM AUTHOR]