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Introduction: With the increase in life expectancy and consequent aging of the population, degenerative lumbar spine diseases tend to increase its number exponentially. Several treatment options are available to treat degenerative spinal diseases, such as laminectomies, posterior fusions, and interbody fusions, depending on their locations, correction necessities, and surgeon philosophy. With the advance in technology and surgical knowledge, minimally invasive techniques (MIS) arose as a solution to reduce surgical morbidity, while maintaining the same benefits as the traditionally/open surgeries. Several studies investigated the possible advantages of MIS techniques against the traditional open procedures. However, those articles are usually focused only on one technique or on one pathology.Methods: The electronic databases, including PubMed, Google Scholar, Ovid, and BVS, were systematically reviewed. Only original articles in English or Portuguese were added to the review, the revision was performed following the PRISMA guideline.Results: Fifty-three studies were included in the meta-analysis. Of the studied outcomes the Length of Stay Odds of complications, Blood Loss, and Surgery costs presented significantly favored MIS approaches, while the Last FUP ODI score, and Surgery Time did not differ among the groups.Conclusion: Minimally invasive techniques are a remarkably interesting option to traditional open surgeries, as these procedures showed a significant reduction in blood loss, hospitalization time, complications, and surgical costs. [ABSTRACT FROM AUTHOR]

Purpose: To explore risk profiles of patients scheduled for lumbar spinal fusion (LSF) and their association with short-term recovery of patient after surgery.Methods: Forty-nine patients scheduled for elective 1-3 level LSF between March 2019 and June 2020 were included. Patients underwent a preoperative risk screening, consisting of an anamnesis, questionnaires and physical performance tests. A latent profile analysis (LPA) was used to identify possible risk profiles within this population.Results: Two risk profiles could be established: a fit and deconditioned risk profile. A significant between-profile difference was found in smoking status (p = 0.007), RAND36-PCS (p < 0.001), Timed Up and Go (TUG) (p < 0.001), de Morton Morbidity Index (DEMMI) (p < 0.001), finger floor distance (p = 0.050), motor control (p = 0.020) and steep ramp test (p = 0.005). Moreover, the fit risk profile had a significant shorter time to functional recovery (3.65 days versus 4.89 days, p = 0.013) and length of hospital stay (5.06 days versus 6.00 days, p = 0.008) compared to the deconditioned risk profile. No differences in complication rates between both risk profiles could be established. Allocation to a risk profile was associated with the functional recovery rate (p = 0.042), but not with LOS or complications.Conclusion: This study found a fit and deconditioned risk profile. The patients with a fit risk profile perceived a better quality of life, performed better in mobility, motor control, cardiopulmonary tests and showed also a significant shorter stay in the hospital and a shorter time to functional recovery. Preoperatively establishing a patient's risk profile could aid in perioperative care planning and preoperative decision-making. [ABSTRACT FROM AUTHOR]

Purpose: To investigate potential associations between preoperative MRI findings and patient reported outcome measures (PROMs) after surgery for lumbar spinal stenosis (LSS).Methods: The NORDSTEN trial included 437 patients. We investigated the association between preoperative MRI findings such as morphological grade of stenosis (Schizas grade), quantitative grade of stenosis (dural sac cross-sectional area), disc degeneration (Pfirrmann score), facet joint tropism and fatty infiltration of the multifidus muscle, and improvement in patient reported outcome measures (PROMs) 2 years after surgery. We dichotomized each radiological parameter into a moderate or severe category. PROMs i.e., Oswestry Disability Index (ODI), Zurich Claudication Questionnaire (ZCQ) and Numeric rating scale (NRS) for back and leg pain were collected before surgery and at 2 year follow-up. In the primary analysis, we investigated the association between MRI findings and ODI score (dichotomized to ≥ 30% improvement or not). In the secondary analysis, we investigated the association between MRI findings and the mean improvement on the ODI-, ZCQ- and NRS scores. We used multivariable regression models adjusted for patients' gender, age, smoking status and BMI.Results: The primary analysis showed that severe disc degeneration (Pfirrmann score 4-5) was significantly associated with less chance of achieving a 30% improvement on the ODI score (OR 0.54, 95% CI 0.34, 0.88). In the secondary analysis, we detected no clinical relevant associations.Conclusion: Severe disc degeneration preoperatively suggest lesser chance of achieving 30% improvement in ODI score after surgery for LSS. Other preoperative MRI findings were not associated with patient reported outcome. [ABSTRACT FROM AUTHOR]

Purpose: Significant risk of injury to the lumbar plexus and its departing motor and sensory nerves exists with lateral lumbar interbody fusion (LLIF). Several cadaveric and imaging studies have investigated the lumbar plexus position with respect to the vertebral body anteroposterior plane. To date, no systematic review and meta-analysis of the lumbar plexus safe working zones for LLIF has been performed.Methods: This systematic review was conducted according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Relevant studies reporting on the position of the lumbar plexus with relation to the vertebral body in the anteroposterior plane were identified from a PubMed database query. Quantitative analysis was performed using Welch's t test.Results: Eighteen studies were included, encompassing 1005 subjects and 2472 intervertebral levels. Eleven studies used supine magnetic resonance imaging (MRI) with in vivo subjects. Seven studies used cadavers, five of which performed dissection in the left lateral decubitus position. A significant correlation (p < 0.001) existed between anterior lumbar plexus displacement and evaluation with in vivo MRI at all levels between L1-L5 compared with cadaveric measurement. Supine position was also associated with significant (p < 0.001) anterior shift of the lumbar plexus at all levels between L1-L5.Conclusions: This is the first comprehensive systematic review and meta-analysis of the lumbar neural components and safe working zones for LLIF. Our analysis suggests that the lumbar plexus is significantly displaced ventrally with the supine compared to lateral decubitus position, and that MRI may overestimate ventral encroachment of lumbar plexus. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to determine the effect of age on the psoas and posterior paraspinal muscles (PPM; multifidus muscle and erector spinae) and to evaluate potential sex-related differences.Methods: MRI-based quantitative assessments of the cross-sectional area (CSA), the functional cross-sectional area (fCSA), the fat area (FAT) and the proportion of intramuscular fat (FI) were conducted on patients undergoing lumbar fusion surgery between 2014 and 2021. The regions of interest were the psoas muscle and the PPM at the superior endplate of L4. The left and right sides of the muscle groups were summarized and normalized by the patient's height (cm2/m2). The relationships between age and muscular parameters were analyzed stratified by sex.Results: A total of 195 patients (57.9%female) with a median age of 64.2 years and a body mass index of 28.3 kg/m2 were analyzed. The CSAPsoas was 7.7 cm2/m2 and differed significantly between females and males (p < 0.001); likewise, the fCSAPsoas differed significantly between the sexes. The CSAPPM was 18.8 cm2/m2 with no sex-specific differences. Significant differences were found in the FIPPM (males: 41.1% vs. females: 47.9%; p < 0.001), but not in the FIPsoas (males: 3.7% vs. females: 4.5%; p = 0.276). Considering the effect of age on FI, a significant positive correlation was observed for the PPMs for both sexes. Only in women, there was a negative correlation between age and CSAPsoas (ρ =  - 0.248; p = 0.008), FATPsoas (ρ =  - 0.421; p < 0.001) and FIPsoas (ρ =  - 0.371; p < 0.001).Conclusion: This study demonstrated sex-specific differences in spinal muscle morphology in relation to patient age. With increasing age there was a decrease in FIPsoas in women only, unlike in the PPMs in which there was increased FI that was significantly higher in women compared to men. [ABSTRACT FROM AUTHOR]

Purpose: Lumbar fusion is widely used to treat degenerative and traumatic conditions of the spine, with various perioperative complications. This study compared lumbar fusion complications in patients with and without chronic hyperlipidemia.Methods: Using the MSpine division of the PearlDiver database, patients with or without chronic hyperlipidemia who underwent lumbar fusions were identified. The appropriate Current Procedural Terminology (CPT) codes identified patients with single- or multi-level lumbar spinal fusion surgeries. International Classification of Diseases (ICD-9 and ICD-10) codes identified patients with chronic hyperlipidemia. The surgical and medical complications were obtained utilizing the appropriate ICD-9, ICD-10, and CPT codes. Propensity score matching analysis was used to control for confounding factors. Chi-square test was applied to compare the incidence of complications among different groups.Results: In single-level fusion group, patients with hyperlipidemia had a higher incidence of wound complications (P < 0.001), surgical site infection (P < 0.001), failed back syndrome (P < 0.001), hardware removal (P < 0.001), deep venous thrombosis/pulmonary embolism (P = 0.031), myocardial infarction (P < 0.001) cerebrovascular accident (P < 0.001), renal failure (P < 0.001), sepsis (P < 0.001), and urinary tract infection/incontinence (P < 0.001). In multi-level fusion group, patients with hyperlipidemia had a higher incidence of nerve root injury (P = 0.034), wound complications (P < 0.001), surgical site infection (P < 0.001), failed back syndrome (P < 0.001), hardware removal (P < 0.001), revision (P = 0.002), myocardial infarction (P < 0.001), renal failure (P < 0.001), and urinary tract infection/incontinence (P < 0.001).Conclusion: Following lumbar fusion, patients with chronic hyperlipidemia have an increased risk of perioperative complications, including wound complications, surgical site infection, failed back surgery syndrome, hardware removal, myocardial infarction, renal failure, and urinary tract infection/incontinence. [ABSTRACT FROM AUTHOR]

Objectives: The purpose of the current study was to explore radiographic predictors for recurrence of lumbar symptoms after prioritized cervical surgery in patients with tandem spinal stenosis (TSS).Methods: The current retrospective cohort study included 74 patients with TSS, who underwent prioritized cervical surgery. Based on presence or absence of improvement in lower limb symptoms, patients were grouped into improved and non-improved groups. Medical records and radiological parameters including age, sex, body mass index, cervical and lumbar parameters were analyzed. In improved group, patients were divided into relapsed and non-relapsed groups based on recurrence in lower limb symptoms.Results: Lumbar symptoms improved in 70.1% (n = 52) of patients. Comparison between the improved and non-improved group showed that there were no statistically significant differences in cervical parameters while comparisons between the relapsed and non-relapsed groups showed significant differences in redundant nerve roots (RNRs) (p = 0.029), narrow segment (p = 0.042) and lumbar stenosis index (LSI) (p = 0.003). In multivariate logistic regression analysis, LSI > 10 (p = 0.016) was independently associated with recurrence of lumbar symptoms.Conclusions: Finding of the current study indicated that LSI > 10 was associated with recurrence of lumbar symptoms in TSS patients following cervical surgery. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to investigate reasons and their frequency for why spine surgeons subspecializing in total disc replacement (TDR) performed lumbar fusion rather than TDR.Methods: The study was based on a consecutive series of 515 patients undergoing lumbar TDR or fusion during a 5-year period by three surgeons specializing in TDR. For each fusion patient, the reason for not performing TDR was recorded.Results: TDR was performed in 65.4% (n = 337) of patients and the remaining 34.6% (n = 178) underwent anterior lumbar interbody fusion (ALIF ± posterior instrumentation). Of the 178 fusion patients, the most common reason for fusion was combined factors related to severe degenerative changes (n = 59, 11.5% of the study population). The second most common reason was > Grade 1 spondylolisthesis (n = 32, 6.2%), followed by insurance non-coverage (n = 24, 4.7%), and osteopenia/osteoporosis (n = 13, 2.5%). Fusion patients were significantly older than TDR patients (52.5 vs. 41.6 years; p < 0.01). There was no significant difference with respect to gender (41.2% female vs. 43.8% female, p > 0.05) or the percentage of patients with single-level surgery (61.2% vs. 56.7%, p > 0.05).Conclusion: The most common reason for not performing lumbar TDR was related to anatomic factors that may compromise stability of the operated segment and/or TDR functionality. The older age of fusion patients may be related to these factors. This study found that many patients are appropriate candidates for lumbar TDR. However, even among TDR subspecialists, fusion is preferred when there are factors that cannot be addressed with TDR and/or may compromise implant functionality. [ABSTRACT FROM AUTHOR]

Introduction: Being able to quantify the invasiveness of a surgical procedure is important to weigh up its associated risks, since invasiveness governs the blood loss, operative time and likelihood of complications. Mirza et al. (Spine (Phila Pa 1976) 33:2651-2661, 2008) published an invasiveness index for spinal surgery. We evaluated the validity of a modified version of the Mirza invasiveness index (mMII), adapted for use with registry data.Methods: A cross-sectional analysis was performed with data acquired from the Spine Tango registry including 21,634 patients. The mMII was calculated as the sum of six possible interventions on each vertebral level: decompression, fusion and stabilization either on anterior or posterior structures. The association between the mMII and blood loss, operative time and complications was evaluated using multiple regression, adjusting for possible confounders.Results: The mean (± SD) mMII was 3.9 ± 5.0 (range 0-40). A 1-point increase in the mMII was associated with an additional blood loss of 12.8% (95% CI 12.6-13.0; p < 0.001) and an increase of operative time of 10.4 min (95% CI 10.20-10.53; p < 0.001). The R2 for the blood loss model was of 43% and for operative time, 47%. The mean mMII was significantly (p < 0.001) higher in patients with surgical complications (4.5 ± 5.6) and general medical complications (6.5 ± 7.0) compared to those without (3.8 ± 4.9). Our results were comparable to those reported in the original publication of Mirza et al. CONCLUSION: The mMII appeared to be a valid measure of surgical invasiveness in our study population. It can be used in predictor models and to adjust for surgical case-mix when comparing outcomes in different studies or different hospitals/surgeons in a registry. [ABSTRACT FROM AUTHOR]

Objective: To study radiological and clinical differences between robotic-assisted pedicle screw fixation with and without real-time optical tracking.Methods: Patients who underwent lumbar internal fixation in our hospital from June 2017 to February 2020 were divided into Tinavi group (with optical tracking) and Renaissance group (without optical tracking) according to assisted technology. The imaging data of the patients were collected, and the accuracy of screw implantation was measured according to Rampersaud A-D grade. Clinical outcomes such as operative time, fluoroscopic time and radiations dose were also collected.Results: A total of 376 patients were included, including 201 patients in the Tinavi group with 968 screws implanted and 175 patients in the Renaissance group with 822 screws implanted. The accuracy of "perfect" and "clinically acceptable" pedicle screw implantation in the Tinavi group was 94.9%-98.7%, respectively, while in the Renaissance group was 91.2%-94.5%, respectively. There was significant difference between the two groups (P < 0.05). The operative time and operative time per screw in the Tinavi group were lower than those in the Renaissance group. However, fluoroscopic time per screw and radiations dose of the Tinavi group were significantly higher than those of the Renaissance group.Conclusion: Optical tracking in robotic system appears to increase accuracy because of the ability to detect the real-time position of the patient. Although there are still many problems to be solved, robot with optical tracking system shows its great potential in clinical application. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to compare clinical results and fusion rates of uncoated polyetheretherketone (PEEK) cages with titanium-coated PEEK cages in posterior lumbar interbody fusion (PLIF) surgery.Methods: A prospective randomised study including 60 patients with one- or two-segment lumbar degenerative diseases. Patients received either titanium-coated PEEK cages (group A) or uncoated PEEK cages (group B). Fusion rates were evaluated on plain X-rays and CT scans after 6 and 12 months. Clinical follow-up (visual analogue scale, VAS; Oswestry Disability Index score, ODI; EQ-5D) was performed for 24 months.Results: Fifty-five patients (92%) (36 female, 19 male) had a complete follow-up. There were no statistically significant differences in demographic, peri- or intraoperative data between groups A and B. ODI, VAS and EQ-5D improved significantly (p < 0.001) after surgery without statistically significant differences between the two groups. Overall, 65 operated segments could be evaluated for fusion (group A: 29 segments, group B: 36 segments, p = 0.6). Osseous integration of the cage surface improved significantly (p < 0.001) in both groups between 6 and 12 months after surgery. At 12-month follow-up, neither radiolucency nor signs of instability or dislocation were noted. Fusion was present in CT scans as follows: (a) bone growth through cage pores (A: 100%, B: 100%); (b) bone growth outside the cages (A: 48%, B: 61%; p = 0.3).Conclusions: PEEK and titanium-coated PEEK cages for PLIF produce equally favourable clinical and radiological results up to 24 months post-surgery. The fusion rate was not different. [ABSTRACT FROM AUTHOR]

Purpose: It is unclear if minimally invasive techniques reduce the rate of perioperative complications when compared to traditional open approaches to the lumbar spine. Our aim was to evaluate perioperative complications in patients that underwent MIS and conventional open techniques for degenerative lumbar pathology.Methods: A retrospective review of a prospectively collected database identified 1435 patients that underwent surgery for degenerative lumbar pathology from January 2013-2016. We evaluated the rates of deep vein thrombosis, pulmonary embolism, urinary tract infection, and pneumonia. Groups were analyzed based on decompression alone as compared with decompression and fusion for both MIS and traditional open techniques.Results: Patients that underwent traditional open lumbar decompression surgery were more likely to develop a DVT (P = .01) than those undergoing MIS decompression. There was no significant difference in rates of PE (P = .99), UTI (P = .24), or pneumonia (P = .56). Patients that underwent traditional open lumbar fusion surgery compared to MIS fusion were also more likely to have a PE (P = .03). There was no significant difference in rates of DVT (P = .22), UTI (P = .43), or pneumonia (P = .24).Conclusion: Minimally invasive spinal surgery was found to reduce the rate of DVT for decompression surgeries and reduce the rate of PE for fusion surgeries. [ABSTRACT FROM AUTHOR]

Purpose: Many patients retain sedentary lifestyles after lumbar surgery and incur increased risks of adverse health outcomes. The goal of this study was to assess patients' perspectives about postoperative physical activity.Methods: During routine post-lumbar surgery visits in a tertiary care center, 260 patients were asked open-ended questions about their spine and physical activity. Three investigators reviewed responses and determined themed categories. Patients also completed surveys measuring disability, depressive symptoms, anxiety, and fear-avoidance of physical activity. Surgical complexity was assigned based on operative features.Results: Mean age was 63, and 53% were men. Thirty-nine percent thought walking was good for the spine, particularly among those with less fear-avoidance, less disability, and less complex surgery. Spine benefits were cited (42%) for the short-term ("faster recovery") and long-term ("decreases chances of another surgery"), particularly by younger patients. To increase activity, patients suggested spine-specific techniques (35%, "use railings") and advised caution (24%, "pace yourself"). The major deterrent was persistent back pain (36%) particularly for those with worse disability, and more depressive symptoms, anxiety, complex surgery, and fear-avoidance. Our findings consistently fit with the Social Cognitive Theory of health behavior which posits a dynamic three-way interaction of personal factors, environmental influences, and behavior.Conclusions: Patients acknowledge short- and long-term benefits of physical activity for their spine and overall health; however, many are deterred from increasing activity by spine-related concerns. Interventions to improve physical activity should foster self-efficacy and self-direction and should be reinforced by members of the spine care team who are knowledgeable about prudent activities. [ABSTRACT FROM AUTHOR]

Purpose: Percutaneous pedicle screw (PPS) fixation has been commonly used for various spine surgeries. Rigid PPS fixation is necessary to decrease the incidence of screw loosening in osteoporotic spine. Recently, we have reported biomechanical advantages of augmentation technique using hydroxyapatite (HA) granules for PPS fixation in synthetic bone. However, its biomechanical performance in augmenting PPS fixation for osteoporotic spine has not been fully elucidated. The aim of the present study is to perform a cadaveric biomechanical analysis of PPS fixation augmented with HA granules.Methods: Thirty osteoporotic lumbar vertebrae (L1-L5) were obtained from 6 cadavers (3 men and 3 women; age 80 ± 9 years; bone mineral density 73 ± 9 mg/cm3). The maximal pullout strength and maximal insertion torque were compared between the screws inserted into the vertebrae with and without augmentation. In toggle testing, the number of craniocaudal toggle cycles and maximal load required to achieve the 2-mm screw head displacement were also compared.Results: The maximal pullout strength in the screws augmented with HA granules was significantly greater compared to those without augmentation (p < 0.05). The augmentation significantly increased the maximal insertion torque of the screws (p < 0.05). Moreover, the number of toggle cycles and the maximal load required to reach 2 mm of displacement were significantly higher in the augmented screws (p < 0.05).Conclusion: The PPS fixation was significantly enhanced by the augmentation with HA granules in the osteoporotic lumbar spine. The PPS fixation augmented with HA granules might decrease the incidence of screw loosening and implant failure in patients with osteoporotic spine. [ABSTRACT FROM AUTHOR]

Purpose: The purposes of this study were to analyse the correlations between the inflection point (IP) and spinal sagittal parameters and to establish the corresponding linear regressions in asymptomatic adults.Methods: A total of 205 asymptomatic subjects older than 18 years were recruited between April 2017 and September 2019. A full-spine, standing X-ray was collected for each subject. The following parameters were documented: the IP, the apices of thoracic kyphosis (TKA) and lumbar lordosis (LLA), the distance between the plumb line of the thoracic apex (TAPL) or lumbar apex (LAPL) and gravity plumb line, thoracic kyphosis (TK), lumbar lordosis (LL) and the upper arc and the lower arc of lumbar lordosis (LLUA and LLLA, respectively). The correlations between the IP and the above parameters and between the thoracic and lumbar parameters were analysed. The level of significance was P < 0.05.Results: The IP was statistically correlated with age (rs = 0.327), the TKA (rs = 0.639), the TAPL (rs = 0.338), TK (rs = 0.391), the LLA (rs = 0.545), the LAPL (rs = - 0.383), the LLUA (rs = 0.371) and the LLLA (rs = - 0.145) but was not linked with LL (rs = 0.118). In addition, there were relationships between the TKA and LLA (rs = 0.397), the TAPL and LAPL (rs = - 0.357), TK and LL (rs = 0.529), TK and the LLUA (rs = 0.742) and TK and the LLLA (rs = 0.148).Conclusion: The IP was significantly related to spinal sagittal alignment in asymptomatic adults. Moreover, predictive formulae for sagittal parameters as a function of the IP were developed, which are helpful for surgeons in comprehending the regulatory mechanisms of spinal sagittal alignment and designing an ideal therapeutic plan. These slides can be retrieved under Electronic Supplementary Material. [ABSTRACT FROM AUTHOR]

Purpose: In this prospective study, we aim to determine surgical outcomes in patients with lumbar spinal stenosis (LSS) 10 years after surgery.Methods: The study population consisted of 96 LSS patients who underwent decompressive surgery, 72 of whom participated in the 10-year follow-up. The patients completed a questionnaire preoperatively and 3 months, 5 years, and 10 years postoperatively. Outcome measures were satisfaction with the surgical outcomes, the Oswestry Disability Index (ODI), the visual analog scale (VAS), the numeric rating scale (NRS-11), and walking ability quantified in meters. Postoperative improvements at 5 and 10 years were analyzed using linear mixed models. Furthermore, comparisons between postoperative time points were made for clinical courses of pain, disability, and walking ability.Results: At the 10-year follow-up, 68% of the patients were satisfied with the surgical outcomes. All the measured outcomes showed statistically significant improvement from baseline to the 5- and 10-year follow-up. The mean VAS score was 9.8 mm higher at the 5-year follow-up and 7.8 mm at the 10-year follow-up compared to the 3-month follow-up point. Similarly, the mean ODI was 4.8% higher at the 10-year follow-up compared to the 3-month follow-up point.Conclusion: This study reports the clinical course of pain, disability, and walking distance after LSS surgery with the 10-year follow-up. Based on our study results, patients with LSS could expect to have positive effects of their back surgery up to 10 years. However, minor worsening in pain and disability may occur and one-fourth of the patients may need a reoperation during the 10-year follow-up period. [ABSTRACT FROM AUTHOR]

Purpose: To investigate if the presence or absence of preoperative endplate Modic changes (MC) is predictive for clinical outcomes in degenerative lumbar spinal stenosis (DLSS) patients undergoing decompression-alone or decompression with instrumented fusion surgery.Methods: Two hundred five patients were included and categorized into four groups; 102 patients into the decompression-alone group with MCs, 41 patients into the fusion group with MCs, 46 patients into the decompression-alone group without MCs, and 16 patients into the fusion group without MCs. Clinical outcome was quantified with changes in spinal stenosis measure (SSM) symptoms, SSM function, NRS pain, and EQ-5D-3L sum score over time (measured at baseline, 12-, 24-, and 36-month follow-up) and minimal clinically important difference (MCID) in SSM symptoms, SSM function, and NRS pain from baseline to 36-month follow-up. To investigate if possible effects of MCs had been modified or hidden by confounding variables, we used the group LASSO method to search for good prognostic models.Results: There were no obvious differences in any of the clinical outcome measures between groups at baseline. At 12 months, most patients have improved in all outcomes and maintained improved conditions over time (no significant group differences). Between 70 and 90 percent of the patients maintained a clinically important improvement up to 36 months.Conclusions: Endplate MCs have no significant influence on clinical outcome parameters in patients with lumbar spinal stenosis compared to patients without MCs, independent of the chosen surgical strategy. All patients benefitted from surgical therapy up to 36-month follow-up. These slides can be retrieved under Electronic Supplementary Material. [ABSTRACT FROM AUTHOR]

Purpose: As yet, there are no studies describing a relationship between radiographic subsidence after lumbar total disc replacement (TDR) and patient symptoms. To investigate if subsidence, in terms of penetrated bone volume or angular rotation over time (ΔPBV and ΔAR), is related to clinical outcome. To assess if subsidence can be predicted by position implant asymmetry (IA) or relative size of the TDR, areal undersizing index (AUI) on direct post-operative radiographs.Methods: Retrospective cohort study consists of 209 consecutive patients with lumbar TDR for degenerative disc disease. A three-dimensional graphical representation of the implant in relation to the bony endplates was created on conventional radiographs. Consequently, the PBV, AR, IA and AUI were calculated, direct post-operative (DPO) and at last follow-up (LFU). For clinical evaluation, patients with substantial pain (VAS ≥ 50) and malfunction (ODI ≥ 40) were considered failures.Results: At a mean follow-up of 16.7 years, 152 patients (73%) were available for analysis. In 32 patients, revision by spinal fusion had been performed. Both ΔAR (4.33° vs. 1.83°, p = 0.019) and ΔPBV (1448.4 mm3 vs. 747.3 mm3, p = 0.003) were significantly higher in the failure-compared to the success-group. Using ROC curves, thresholds for symptomatic subsidence were defined as ΔPBV ≥ 829 mm3 or PBV-LFU ≥ 1223 mm3 [area under the curve (AUC) 0.723, p = 0.003 and 0.724, p = 0.005, respectively]. Associations between symptomatic subsidence and AUI-DPO ≥ 0.50 (AUC 0.750, p = 0.002) and AR-DPO ≥ 3.95° (AUC 0.690, p = 0.022) were found.Conclusion: Subsidence of a TDR is associated with a worse clinical outcome. The occurrence of subsidence is higher in case of incorrect placement or shape mismatch. [ABSTRACT FROM AUTHOR]

Purpose: Disc herniations are usually treated by decompression of the spinal nerves via a partial nucleotomy. As a consequence of reduced disc height (DH), reduced intradiscal pressure (IDP) and increased range of motion (ROM), accelerated degeneration may occur. Nucleus replacement implants are intended to restore those values, but are associated with the risk of extrusion.Methods: In six fresh frozen lumbar spinal segments (L2-3/L3-4/L4-5/L5-S1, age median 64.5 years (57-72), Pfirrmann grade 2-3), a prolapse was provoked through a box defect (6 × 10 mm) in the annulus. The herniated nucleus material was removed and replaced by a novel collagen-based nucleus implant. An annulus closure device sealed the defect. ROM, neutral zone (NZ) and IDP were measured in the (1) intact and (2) defect state, (3) postoperatively and (4) after cyclic loading (n = 100,000 cycles) applying pure moments (± 7.5 Nm) in flexion-extension, lateral bending and axial rotation. Additionally, the change in DH was determined. Extrusion of implants or nucleus material was evaluated macroscopically.Results: In all specimens, a prolapse could be provoked which decreased DH. Subsequent nucleotomy changed ROM/NZ and IDP considerably. Initial values could be restored by the implantation. Macroscopically, none of the implants nor nucleus material did migrate after cyclic loading.Conclusions: In this study, a prolapse followed by a nucleotomy resulted in a biomechanical destabilisation. Implantation of the nucleus replacement combined with an annulus closure restored the intact condition without showing signs of extrusion nor migration after cyclic loading. Hence, nucleus replacements could have a new chance in combination with annulus closure devices. [ABSTRACT FROM AUTHOR]

Purpose: To conduct a meta-analysis to describe clinical course of pain and disability in adult patients post-lumbar discectomy (PROSPERO: CRD42015020806).Methods: Sensitive topic-based search strategy designed for individual databases was conducted. Patients (> 16 years) following first-time lumbar discectomy for sciatica/radiculopathy with no complications, investigated in inception (point of surgery) prospective cohort studies, were included. Studies including revision surgery or not published in English were excluded. Two reviewers independently searched information sources, assessed eligibility at title/abstract and full-text stages, extracted data, assessed risk of bias (modified QUIPs) and assessed GRADE. Authors were contacted to request raw data where data/variance data were missing. Meta-analyses evaluated outcomes at all available time points using the variance-weighted mean in random-effect meta-analyses. Means and 95% CIs were plotted over time for measurements reported on outcomes of leg pain, back pain and disability.Results: A total of 87 studies (n = 31,034) at risk of bias (49 moderate, 38 high) were included. Clinically relevant improvements immediately following surgery (> MCID) for leg pain (0-10, mean before surgery 7.04, 50 studies, n = 14,910 participants) and disability were identified (0-100, mean before surgery 53.33, 48 studies, n = 15,037). Back pain also improved (0-10, mean before surgery 4.72, 53 studies, n = 14,877). Improvement in all outcomes was maintained (to 7 years). Meta-regression analyses to assess the relationship between outcome data and a priori potential covariates found preoperative back pain and disability predictive for outcome.Conclusion: Moderate-level evidence supports clinically relevant immediate improvement in leg pain and disability following lumbar discectomy with accompanying improvements in back pain. These slides can be retrieved under Electronic Supplementary Material. [ABSTRACT FROM AUTHOR]

Purpose: Lumbar epidural steroid injections (LESIs) are widely utilized for back pain. However, as studies report adverse effects from these injections, defining a safe interval for their use preoperatively is necessary. We investigated the effects of preoperative LESI timing on the rates of recurrent microdiscectomy.Methods: This study utilized the PearlDiver national insurance claims database. Microdiscectomy patients were stratified by the timing of their most recent LESI prior to surgery into bimonthly cohorts (0-2 months, 2-4 months, 4-6 months). This first cohort was further stratified into biweekly cohorts (0-2 weeks, 2-4 weeks, 4-6 weeks, 6-8 weeks). The 6-month reoperation rate was assessed and compared between each injection cohort and a control group of patients with no injections within 6 months before surgery. Univariate analyses of reoperation were conducted followed by multivariate analyses controlling for risk factors where appropriate.Results: A total of 12,786 microdiscectomy patients were identified; 1090 (8.52%) received injections within 6 months before surgery. We observed a significant increase in the 6-month reoperation rates in patients who received injections within 6 weeks prior to surgery (odds ratio [OR] 1.900, 1.218-2.963; p = 0.005) compared to control. No other significant differences were observed.Discussion: In this study, microdiscectomy performed within 6 weeks following LESIs was associated with a higher risk of reoperation, while microdiscectomy performed more than 6 weeks from the most recent LESI demonstrated no such association with increased risk. Further research into the interaction between LESIs and recurrent disk herniation is necessary. [ABSTRACT FROM AUTHOR]

Purpose: Surgeons need tools to provide individualised estimates of surgical outcomes and the uncertainty surrounding these, to convey realistic expectations to the patient. This study developed and validated prognostic models for patients undergoing surgical treatment of lumbar disc herniation, to predict outcomes 1 year after surgery, and implemented these models in an online prediction tool.Methods: Using the data of 1244 patients from a large spine unit, LASSO and linear regression models were fitted with 90% upper prediction limits, to predict scores on the Core Outcome Measures Index, and back and leg pain. Candidate predictors included sociodemographic factors, baseline symptoms, medical history, and surgeon characteristics. Temporal validation was conducted on 364 more recent patients at the same unit, by examining the proportion of observed outcomes exceeding the threshold of the 90% upper prediction limit (UPL), and by calculating mean bias and other calibration measures.Results: Poorer outcome was predicted by obesity, previous spine surgery, and having basic obligatory (rather than private) insurance. In the validation data, fewer than 12% of outcomes were above the 90% UPL. Calibration plots for the model validation showed values for mean bias < 0.5 score points and regression slopes close to 1.Conclusion: While the model accuracy was good overall, the prediction intervals indicated considerable predictive uncertainty on the individual level. Implementation studies will assess the clinical usefulness of the online tool. Updating the models with additional predictors may improve the accuracy and precision of outcome predictions. These slides can be retrieved under Electronic Supplementary Material. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study is to investigate, using a meta-analysis, differences in safety and effectiveness between a titanium mesh bone graft and bone graft alone for the treatment of thoracolumbar spinal tuberculosis.Methods: PubMed, Web of Science, Cochrane Library, Chinese National Knowledge Infrastructure, Wanfang (Chinese) and other databases were searched up to April 2019 using predetermined terms. Published studies investigating the safety and effectiveness of a titanium mesh bone graft versus a bone graft alone for the treatment of thoracolumbar spinal tuberculosis were included. Two authors independently extracted the data and evaluated the quality of the included articles. A meta-analysis of relevant outcome indicators was performed using Stata 14 and RevMan 5.3 software.Results: We retrieved 8 retrospective studies that met the inclusion criteria and enrolled a total of 401 patients, including 203 patients in the titanium mesh group and 198 in the bone graft only group. Each study was rated as high quality. The meta-analysis results showed no statistically significant differences between the 2 bone graft methods in terms of surgery-related indicators, clinical effectiveness, imaging and complications.Conclusions: Both titanium mesh and bone grafts alone are effective for the treatment of thoracolumbar spinal tuberculosis based on safety. However, the results of this study do not support the superiority of titanium mesh bone grafts reported in previous studies. Because of the high risk of bias of the conclusions of a meta-analysis of non-randomized studies and the small sample sizes for some of the most important outcomes, randomized controlled trials are expected to further examine the reliability of the present findings. [ABSTRACT FROM AUTHOR]

Purpose: In this study, the authors described the technical notes of percutaneous transforaminal endoscopic lumbar discectomy (PTELD) through unilateral approach and compared PTELD through unilateral versus bilateral approach for L3/4 or L4/5 lumbar disc herniation with bilateral symptoms.Methods: A prospective randomized clinical study was performed from June 2014 to October 2016. A total of 71 patients with lumbar disc herniation (L3/4 or L4/5) and bilateral symptoms were divided randomly into Unilateral-Approach group (n = 35) or Bilateral-Approach group (n = 36). Operation time, blood loss, intraoperative fluoroscopy and recurrences were recorded and analyzed statistically. Visual Analogue Scale scores, Oswestry Disability Index and the MacNab standard were used to analyze the clinical outcomes of the two groups.Results: The baseline data of the two groups were statistically similar. There was significant postoperative improvement in VAS and ODI scores in both the groups, and clinical outcomes are comparable according to the MacNab standard. However, VAS score of back pain at 1 day after surgery in Unilateral-Approach group was significantly lower than that in Bilateral-Approach group (P < 0.05). Moreover, operation time and cumulative time of intraoperative fluoroscopy of Unilateral-Approach group were significantly shorter than that of Bilateral-Approach group (P < 0.05).Conclusion: For L3/4 or L4/5 LDH with bilateral symptoms, PTELD through unilateral approach is effective, with advantage of shorter operation time, shorter cumulative time of intraoperative fluoroscopy and milder postoperative short-term back pain compared to bilateral approach. These slides can be retrieved under Electronic Supplementary Material. [ABSTRACT FROM AUTHOR]

Purpose: To compare the long-term clinical results and complications of two revision strategies for patients with failed total disc replacements (TDRs).Methods: In 19 patients, the TDR was removed and the intervertebral defect was filled with a femoral head bone strut graft. In addition, instrumented posterolateral fusion was performed (removal group). In 36 patients, only a posterolateral instrumented fusion was performed (fusion group). Visual Analogue Scale (VAS) for pain and Oswestry Disability Index (ODI) were completed pre- and post-revision surgery. Intra- and post-operative complications of both revision strategies were assessed.Results: The median follow-up was 12.3 years (range 5.3-24.3). In both the removal and fusion groups, a similar (p = 0.515 and p = 0419, respectively) but significant decrease in VAS (p = 0.001 and p = 0.001, respectively) and ODI score (p = 0.033 and p = 0.013, respectively) at post-revision surgery compared to pre-revision surgery was seen. A clinically relevant improvement in VAS and ODI score was found in 62.5% and 43.8% in the removal group and in 43.5% and 39.1% in the fusion group (p = 0.242 and p = 0.773, respectively). Removal of the TDR was associated with substantial intra-operative complications such as major vessel bleeding and ureter lesion. The percentage of late re-operations for complications such as pseudarthrosis were comparable for both revision strategies.Conclusions: Revision of a failed TDR is clinically beneficial in about half of the patients. No clear benefits for additional TDR removal as compared to posterolateral instrumented fusion alone could be identified. In particular, when considering the substantial risks and complications, great caution is warranted with removal of the TDR. These slides can be retrieved under Electronic Supplementary Material. [ABSTRACT FROM AUTHOR]

Although total disc arthroplasty (TDA) is a common procedure for selected cases of degenerative disc disease, until today there are only two cases of TDA infections reported in the literature. We report three cases of postoperative TDA infections, two developed cutaneous fistulas. To eradicate the infectious site, a staged removal of the device, resolute debridement, and stabilization plus fusion is proposed. Surgeons are challenged by (1) major retroperitoneal vessels adherent to the device, (2) surrounding scar tissue, (3) accompanying retroperitoneal abscess, and (4) technical issues when removing and replacing the implant. A staged multidisciplinary team approach involving vascular and plastic surgery as well as spine specialists is mandatory to achieve good results. [ABSTRACT FROM AUTHOR]

Purpose: Degenerative disc disease (DDD) is a common condition causing low-back pain, disability and, eventually, neurological symptoms. This investigation aimed to investigate intervertebral disc DDD-related changes, evaluating histomorphology and cytokines secretion, and their clinical-radiological correlations.Methods: This is a monocentric prospective observational study. A cohort of patients who underwent microdiscectomy for DDD, from June 2018 to January 2019, were enrolled. Discs samples were examined for histomorphology, chondrons count, immunohistochemistry for Hif-1α, Nf200 and Egr-1. Demographical and clinical data were also collected.Results: Twenty patients were finally included. MRI evaluation showed a Modic I alteration in nine patients and a Modic II in 11. The disability grade was low-moderate (ODI score was ≤ 40%) in eight patients and high (ODI score > 40%) in 12. The Modic I was associated with a low-moderate disability in two (22%) patients and to a high disability in seven (88%) (p < 0.01). In Modic I group and in ODI > 40% groups, there were a significative higher mean disability grade 48.4 (± 8.3)%, number of chondrons per section, cells per chondron, Nf200+ nerve fibers and Hif-1α expression, compared with Modic II and ODI ≤ 40% groups, respectively. There were no differences in terms of Egr-1 expression.Conclusions: The discs with Modic I MRI signal could represent potential targets for medical treatments, whereas Modic II seems to be a more likely point of no return in a degenerative process. Therefore, further investigations are to better investigate inflammatory pathways and degenerative mechanisms in DDD. [ABSTRACT FROM AUTHOR]

Aim: Low back pain (LBP) resulting from degenerative lumbar spine disease is a leading contributor to global disability. Changes in the morphology of the lumbar multifidus muscle on magnetic-resonance imaging (MRI) are associated with worse LBP and disability, but the association between multifidus morphology and post-operative outcomes is not known. The purpose of this systematic review is to examine the relationship between pre-operative multifidus morphology and post-operative changes in pain and disability.Methods: We performed a systematic search using the Cochrane Library, EMBASE, MEDLINE, CINAHL and Scopus databases covering the period from January 1946 to January 2018. The literature was searched and assessed by independent reviewers according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. All relevant papers were assessed for risk of bias according to the Quality in Prognosis Studies tool.Results: The initial search yielded 436 studies, of which 6 studies were included in the analysis. Four studies were at a low risk of bias. These studies included a total of 873 patients undergoing spinal surgery. An association between low fat infiltration and greater improvement in LBP and disability following surgery was identified. There was insufficient evidence to identify a relationship between cross-sectional area (CSA) and LBP or disability.Conclusions: This systematic review found evidence for an association between low multifidus fat infiltration on MRI at baseline and greater reductions in measures of LBP and disability following surgical treatment. There is also limited evidence for an association between larger pre-operative multifidus CSA and improvements in disability, but not pain. The findings of this review should be interpreted with caution due to the small quantity of the available literature. [ABSTRACT FROM AUTHOR]

Purpose: To compare the acute behaviors of pelvic incidence (PI) between elderly adult spinal deformity (ASD) patients with severe and minor sagittal deformity based on SRS-Schwab classification and to identify the mechanism of the variability in PI after long fusion to S1.Methods: Patients aged 60 years or above with available radiographs were included. The following parameters were measured pre- and postoperatively: Thoracic kyphosis, thoracolumbar kyphosis (TLK), lumbar lordosis (LL), PI, pelvic tilt, sacral slope, sagittal vertical axis (SVA), PI-LL and T1 pelvic angle (TPA).Results: Forty-two patients were found with severe sagittal deformity were assigned to Group S, and 60 patients with minor sagittal deformity were assigned to Group M. Immediately after surgery, lumbar curve, TLK and PI-LL were obviously corrected in both groups, while LL, PI, SVA and TPA were significantly increased in Group S alone. PI was significantly increased from 42.6 ± 4.7° to 51.7 ± 6.0° in Group S (P = 0.002), but changed from 45.4 ± 10.2° to 46.3 ± 10.3° in Group M without statistical significance. Pearson correlation analysis showed changes in PI was significantly correlated with changes in SVA (r = 0.415, P = 0.011) in patients with PI increased more than 5°.Conclusion: PI spontaneously increases in elderly ASD patients with severe sagittal deformity after long fusion to sacrum, while is relative invariable in those with minor sagittal deformity. Variation in PI could be considered as a secondary change compensating for the spinal sagittal malalignment under long spinal fusion in elderly patients. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate specific demographic and perioperative variables associated with higher inpatient pain scores following minimally invasive transforaminal lumbar interbody fusion (MIS TLIF).Methods: Patients who underwent a single-level, primary MIS TLIF were retrospectively reviewed. Perioperative outcomes were collected, and postoperative inpatient VAS pain scores were measured. Both bivariate and stepwise multivariate Poisson regressions with robust error variance were used to assess risk factors for average inpatient pain score ≥ 5.0. A final backward stepwise regression model was created using age, gender, smoking status, diabetes status, insurance status, BMI, comorbidity burden, pedicle screw laterality, operative time, and estimated blood loss.Results: A total of 255 patients undergoing primary, single-level MIS TLIF were included. Age less than 50 years, workers' compensation insurance, preoperative VAS pain score ≥ 7, and operative duration ≥ 110 min were associated with greater postoperative pain. However, other variables such as gender, BMI, smoking status, comorbidity burden, diabetes status, and pedicle screw laterality were not associated with increased postoperative pain.Conclusion: The results of this study suggest that younger age, workers' compensation, elevated preoperative pain scores, and longer operative times are independently associated with greater inpatient pain following TLIF. Surgeons can use this information to better assess which patients may require additional pain control following TLIF. Patient expectations of postoperative outcomes in regard to pain and recovery may also be better managed. These slides can be retrieved under Electronic Supplementary Material. (paragraph). Then process the ppt slide as graphical image. [ABSTRACT FROM AUTHOR]

Purpose: The global alignment and proportion (GAP) score was recently developed to consider proportional analysis of spinopelvic alignment and has been indicated for setting surgical goals to decrease the prevalence of mechanical complications. The goal of this study was to clarify the limitations and problems with spinal corrective surgery with minimally invasive lateral lumbar interbody fusion (LLIF) without osteotomy using GAP score, and to establish a preoperative radiographical evaluation to understand the necessity for three-column osteotomy.Methods: We included data from 57 consecutive patients treated with spinal corrective surgery with LLIF and without Schwab grade 3-6 osteotomy for ASD. To evaluate flexibility of the pelvis and lumbar spine, we examined full-length lateral radiographs with patients standing and prone. Correlations between pre- and postoperative radiographic parameters and GAP score were determined.Results: Most patients achieved a sufficiently ideal lumbar lordosis (87.7%), but ideal sacral slope (SS) was achieved in only 50.8% of patients. Preoperative prone SS showed a significant positive correlation with postoperative SS and a significant negative correlation with GAP score. Patients whose preoperative prone SS was larger than pelvic incidence × 0.59-7.5 tended to achieve proportioned spinopelvic alignment by using LLIF.Conclusions: The cause of poor outcome of GAP score for ASD corrective surgery with LLIF without osteotomy is a postoperative small SS. Preoperative prone SS is useful for predicting postoperative SS. When preoperative SS in prone patients is relatively small to ideal as calculated using PI, osteotomy or other correctors should be considered to achieve satisfactory spinopelvic parameters.Level Of Evidence: III. These slides can be retrieved under Electronic Supplementary Material. [ABSTRACT FROM AUTHOR]

Purpose: A variety of alternative grafts to autologous iliac crest bone (ICBG) have been developed for lumbar spondylodesis, due to frequent complications following ICBG harvest. The optimal alternative graft to ICBG, however, remains elusive till now. The purpose of this study was to compare the efficacy and safety of fusion materials in lumbar degeneration diseases and to provide a ranking spectrum of the grafts.Methods: Randomized controlled trials (RCTs) comparing different bone grafts in lumbar arthrodesis were eligible for inclusion. A network meta-analysis was performed for endpoints including fusion rate and incidence of adverse events.Results: Twenty-seven RCTs involving 2488 patients and 13 available interventions were included. rhBMP-2 provided the highest fusion rate, being significantly superior to that of ICBG (OR = 0.21, p < 0.001), autograft local bone (ALB) (OR = 0.18, p = 0.022), rhBMP-7 (OR = 0.15, p < 0.001), allograft (OR = 0.13, p = 0.009), and DBM + ALB (OR = 0.07, p = 0.048). The treatment efficacy of allograft could be significantly enhanced by bone marrow concentrate (BMC) supplying (OR = 0.16, p = 0.010). ICBG ranks second on the frequency of complications, which is significantly higher than that of allograft (OR = 0.14, p = 0.041) and ALB (OR = 0.14, p = 0.030). All of the other comparisons showed similar efficacy and safety profiles between groups.Conclusion: Ranking spectrums of the efficacy and safety for various bone grafts were provided graphically. Though rhBMP-2 was of the highest success rate, the application should be taken with proper caution because of the widely proposed life-threatening adverse events. ALB, ALB plus synthetic ceramic materials and allograft mixed with BMC were also proved to be potentially effective alternative graft to ICBG. These slides can be retrieved under Electronic Supplementary Material. [ABSTRACT FROM AUTHOR]

Purpose: Quantitative computed tomography (QCT) is an alternate imaging method to dual X-ray absorptiometry to measure bone mineral density (BMD). One advantage of QCT is that it allows site-specific volumetric BMD (vBMD) measurements in a small region. In this study, we utilized site-specific, endplate vBMD (EP-vBMD) as a potential predictive marker of severe cage subsidence in standalone lateral lumbar interbody fusion (SA-LLIF) patients and conducted a retrospective comparative study between EP-vBMD and trabecular vBMDs (Tb-vBMD) in the vertebrae.Methods: Patients undergoing SA-LLIF from 2007 to 2016 were retrospectively reviewed. EP-vBMD was defined as the average of the upper and lower endplate volumetric BMDs measured in cortical and trabecular bone included in a 5-mm area of interest beneath the cage contact surfaces. We compared Tb-vBMDs and EP-vBMDs between disk levels that had severe cage subsidence and levels with no severe subsidence.Results: Both EP-vBMD and Tb-vBMD could be measured in 210 levels of 96 patients. Severe cage subsidence was observed in 58 levels in 38 patients. Median (IQR) Tb-vBMD was 120.5 mg/cm3 (100.8-153.7) in the non-severe subsidence group and 117.9 mg/cm3 (90.6-149.5) in the severe subsidence group (p = 0.393), whereas EP-vBMD was significantly lower in the severe subsidence group than the non-severe subsidence group (non-severe subsidence 257.4 mg/cm3 (216.3-299.4), severe subsidence 233.5 mg/cm3 (193.4-273.3), p = 0.026).Conclusion: We introduced a novel site-specific vBMD measurement for cage subsidence risk assessment. Our results showed that EP-vBMD was a reproducible measurement and appeared more predictive for severe cage subsidence after SA-LLIF than Tb-vBMD. These slides can be retrieved under Electronic Supplementary Material. [ABSTRACT FROM AUTHOR]

Purpose: Gamma-aminobutyric acid analogues are commonly used to treat neuropathic and chronic pain before and after spinal surgery in recent years. Aim of this study is to investigate the influence of pregabalin on spinal fusion and to determine the proper pregabalin dose for postoperative utilization in a validated rat intertransverse spinal fusion.Methods: Lumbar intertransverse fusion surgeries performed in four groups of rats according to a previously established rat model for posterolateral spinal fusion. All rats were followed up for 6 weeks at the postoperative period by administering oral pregabalin doses of 10 (D10), 30 (D30) and 100 mg/kg/day (D100) except the control group. All rats were killed after 6 weeks and evaluated in terms of manual palpation, radiographic investigation and histological analysis to investigate posterolateral fusion.Results: Assessment of fusion with manual palpation revealed lower fusion rates in D100 group. In histological analysis, scores were significantly lower in D30 and D100 groups compared to the control group; this finding was interpreted as inhibition of spinal fusion. Radiographic evaluation did not reveal any significant statistical difference between groups.Conclusions: Histological analysis and manual palpation results showed inhibition of spinal fusion formation with high doses of pregabalin. According to these results, administration of high-dose pregabalin should be avoided at the postoperative period until successful fusion is obtained in patients who undergo spinal fusion surgery. These slides can be retrieved under electronic supplementary material. [ABSTRACT FROM AUTHOR]

Purpose: Related to the development and diffusion of ALIF and XLIF, it is possible to correct sagittal malalignment in selected cases of lumbar degenerative discopathy with a relatively low invasiveness. Still, the malposition or the inappropriate size of the implanted cages may lead to the subsidence of the vertebral endplates with loss of correction as well as a decrease in the potential to restore spinal biomechanics in the long run. The aim of this study is to evaluate safety, feasibility, and preliminary clinical and radiological results when using custom-made, trabecular titanium cages in ALIF and XLIF procedures.Methods: We prospectively evaluated 18 consecutive patients who underwent either an ALIF or an XLIF procedure with the implant of a custom-made, trabecular titanium cage for lumbar degenerative disease with sagittal imbalance, with a minimum of 1-year clinical and radiological follow-up.Results: After a mean follow-up of 14 months, the Oswestry score dropped to a mean of 13 from a preoperative value of 48 (p < 0.0001). Lumbar lordosis was significantly improved, especially in the lower lumbar segment L4-S1 (+ 11 ± 7°; p < 0.0001). No cases of subsidence were noted.Conclusions: Custom-made, trabecular titanium cages allowed a segmental, steady, durable sagittal correction via ALIF and XLIF approaches. The absence of cage subsidence at 1 year encourages further studies on a larger cohort with longer follow-up. These slides can be retrieved under Electronic Supplementary Material. [ABSTRACT FROM AUTHOR]

Background and Purpose: Loss to follow-up in observational studies may skew results and hamper study reliability. We evaluated the importance of loss to follow-up in the Swedish spine register.Patients: Patients operated in the lumbar spine and scheduled for a postal questionnaire follow-up during part of 2016 were identified. Out of the 351 patients, 203 had responded. After multiple attempts, 115 of the 148 non-responders were reached; 68 returned the complete questionnaire; and 47 answered a brief questionnaire by phone. Analyses were made with the Chi-square test, analysis of covariance or logistic regression. Some analyses were adjusted.Results: At baseline, the non-responders were younger than the responders (55 vs 61 years, p < 0.001) and had higher Oswestry Disability Index (ODI) (54 vs 48, p = 0.003), lower SF-36 physical component summary score (PCS) (36 vs 40, p = 0.011) and lower EQ-5D (0.17 vs 0.27, p = 0.018). Mean back pain, leg pain, ODI, EQ-5D, SF-36 mental component summary score (MCS) improved significantly in both groups (all p < 0.001). SF-36 PCS did not improve in the non-responder group (p = 0.063). Non-responders perceived less improvement in back pain (global assessment back 60% vs 72%, p = 0.002). At follow-up, there were no differences in patient-reported outcome measures between the groups (all p ≥ 0.06), with the exception of a lower SF-36 MCS among the non-responders (p = 0.015).Interpretation: After surgery for lumbar spine degenerative disorders, non-responders achieve similar outcome as responders in the Swedish spine register, with the exception of a lower mental health and less perceived improvement in back pain. These slides can be retrieved under Electronic Supplementary Material. [ABSTRACT FROM AUTHOR]

Objective: To compare surgical outcomes between seven different approaches for thoracolumbar corpectomy/spondylectomy in the setting of spinal metastasis.Methods: A systematic review of literature was performed including articles on corpectomy for thoracolumbar spinal metastasis. Data were extracted and sorted by surgical approach: en bloc spondylectomy (group 1), transpedicular (group 2), costotransversectomy (group 3), mini-open retropleural/retroperitoneal (group 4a), lateral extracavitary approach (group 4b), open transthoracic/transretroperitoneal (group 5), and thoracoscopic (group 6). Comparison of demographics, blood loss, directly procedure related complications, operating time, and postoperative improvement of pain.Results: A total of 63 articles were included comprising data of 774 patients with various primary tumor entities. Mean age was 51.8 years, 54% of patients were female, on average 1.46 levels were treated per patient, and mean follow-up was 1.59 years. The following statistically significant findings were observed: Blood loss was lowest for the mini-open retropleural/retroperitoneal (917 ml), thoracoscopic (1107 ml) and transthoracic approach (1172 ml) versus the posterior approach groups (1633-2261 ml); directly procedure related complications were lowest for mini-open retropleural/retroperitoneal and thoracoscopic approach (0% each) versus 7-15% in the other groups; operating time was lowest in mini-open retropleural/retroperitoneal approach (184 min) versus 300-588 min in the other groups.Conclusion: Less invasive approaches (mini-open retropleural/retroperitoneal and thoracoscopic) not only had superior outcome in terms of blood loss and operating time, but also were shown to be safe techniques in cancer patients with low rates of procedure-related complications. These slides can be retrieved under Electronic Supplementary Material. [ABSTRACT FROM AUTHOR]

Purpose: To compare the clinical and economic outcomes of facet versus pedicle screw instrumentation for single-level circumferential lumbar spinal fusion.Methods: Outcomes included self-assessment of back and leg pain, pain drawing, ODI, pain medication usage, and procedure success. The CEA was based on the 10-year data collected, and the base-case was from a US payer perspective. Costs included the index surgery, additional surgeries, outpatient/ED visits, and medications. To determine quality-adjusted life years (QALYs), ODI scores were used to predict SF-6D utilities. Sensitivity analyses were performed from a modified payer perspective including device costs and from a societal perspective including productivity loss. Discounted and undiscounted incremental costs and QALYs were calculated. Bootstrapping was performed to estimate the distribution of incremental costs and effects.Results: Clinical improvement was significant from pre-op to 10-year follow-up for both groups (p < 0.01 for all outcomes scales). Outcomes were significantly better for back pain and ODI for the facet versus pedicle group at all follow-up periods > 1 year (p < 0.05). In the CEA base-case, facets had more QALYs (0.68) and lower costs (- $8650) per person compared with pedicle screws. Therefore, facets were dominant (i.e., provided cost savings and greater QALYs) compared with pedicle screws. Facets had a 97% probability of being below a willingness-to-pay threshold of $20,000 per QALY gained and were estimated to be dominant over pedicle screws in 84% of the simulations.Conclusion: One-level circumferential spinal fusion using facet screws was clinically superior and provided cost savings compared with pedicle screw instrumentation in the USA. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate whether left hip positioning widened the access corridor using oblique lateral interbody fusion (OLIF) approach during right lateral decubitus (RLD).Methods: Ten healthy adult volunteers underwent a T2 lumbosacral MRI (1.5 T) in the supine position, RLD position with left hip in extension and then in flexion. L2-L3 to L5-S1 disc spaces were identified. At each level, left psoas surface (in cm2), access corridor (in mm) and vessel movement were calculated in the three positions. Paired t test was used for comparison.Results: The mean surface of the left psoas ranged from 7.83 to 17.19 cm2 in the three positions (p > 0.05). From L2-3 to L4-5, in RLD, when the left hip shifted from extension to flexion, nor the access corridor nor vessel movements were significantly different. When the volunteers shifted from supine to RLD position with hip in extension, arteries moved 3.66-5.61 mm to the right (p < 0.05 at L2-3, L3-4 and L5-S1), while the venous structures moved 0.92-4.96 mm (p < 0.05 at L2-3) to the right. When the position shifted from supine to RLD with hip in flexion, the arterial structures moved 0.47-4.88 mm (p < 0.05 at L2-3 and L3-4) to the right, while the venous structures moved - 0.94 to 4.13 mm (p < 0.05 at L2-3 and L3-4) to the right.Conclusion: Hip positioning was not associated with a significant widening of the surgical corridor. To perform OLIF, we advocate for RLD position with left hip in extension to move away the vascular structures and reduce the psoas volume. These slides can be retrieved under Electronic Supplementary Material. [ABSTRACT FROM AUTHOR]

Objective: To quantify the correlation between patients' psychopathological predisposition, disability and health-related quality of life (QOL) after surgery for degenerative lumbar spine disease.Methods: We prospectively included patients undergoing decompression for degenerative lumbar spinal stenosis, spondylolisthesis or disc herniation with additional fusion of up to two segments. Patients completed a structured psychological assessment including the Center for Epidemiological Studies Depression Scale (ADS-K), Post-Traumatic Stress Scale-10 (PTSS-10), State Trait Anxiety Inventory-State Anxiety and State Trait Anxiety Inventory-Trait Anxiety (STAI-S and STAI-T) and Anxiety Sensitivity Index-3 (ASI-3) before surgery, after 3 and 12 months. Outcome measures included EuroQol 5D (EQ), Short Form-36 (SF-36) and Oswestry Disability Index (ODI) scores.Results: In total, 245 patients between March 2013 and November 2017 received surgery, of which 180 (73.5%) fully completed follow-up after 3 months and 12 months. QOL scores significantly increased by 3 months (EQ: +0.2; p < 0.001; SF-36 PCS: +7.0; p < 0.001; SF-36 MCS: +3.3; p = 0.018), a benefit which was retained at 12 months, without statistically significant difference between fused and non-fused patients. Depressed patients exhibited impaired mean scores of EQ (0.58 vs. 0.36; p < 0.001) and ODI mean scores (35.5 vs. 51.9; p < 0.001) at baseline, which significantly improved and converged with scores of non-depressed patients after 12 months. Linear regression analysis identified statistically significant predictors in age, STAI-T and SF-36 MCS for post-operative QOL and disability.Conclusion: Despite exhibiting pronounced psychological distress preoperatively, patients may significantly benefit from surgery with an outcome equal to psychologically healthy patients after 12 months. These slides can be retrieved under Electronic Supplementary Material. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to compare clinical patient-reported outcomes and radiographic sagittal parameters between obese and non-obese patients following open posterior lumbar spine fusion (PLSF).Methods: A retrospective cohort study was conducted for patients who underwent open PLSF from 2011 to 2018. Patients were classified as obese as per Center for Disease Control and Prevention guidelines if their body mass index (BMI) ≥ 30 kg/m2. Preoperative and final visual analog scale (VAS) back pain, VAS leg pain, and Oswestry Disability Index (ODI) were obtained for both obese and non-obese groups. Achievement of minimal clinically important difference was evaluated. Preoperative, immediate postoperative, and final lumbar plain radiographs were assessed to measure spinopelvic parameters. Additionally, postoperative complication measures were collected.Results: A total of 569 patients were included; 290 (50.97%) patients with BMI < 30 (non-obese) and 279 (49.03%) patients with BMI ≥ 30 (obese). Patients classified as obese were more likely to have a diagnosis of diabetes mellitus (p < 0.001), and American Society of Anesthesiologists Physical Status Classification System of ≥ 3 (p < 0.001). Obese patients had significantly longer operative times (p < 0.001) compared to non-obese patients. There was no difference in radiographic measurements, patient-reported outcomes, postoperative complications, or reoperations between groups.Conclusion: Obese patients had significantly more comorbidities and longer operative time compared to non-obese patients. However, sagittal parameters, patient-reported outcomes, inpatient complications, length of hospital stay, and reoperations were similar between groups. Given these findings, open PLSF can be considered safe and effective in obese patients after thorough consideration of related comorbidities. These slides can be retrieved under Electronic Supplementary Material. [ABSTRACT FROM AUTHOR]

Purpose: To date, there are conflicting reports with no consensus on the influence of bisphosphonates on lumbar fusion. The goal of this study was to compare the radiographic and functional outcomes of patients that had lumbar fusion with and without bisphosphonates.Methods: A systematic search of multiple medical reference databases was conducted for studies comparing bisphosphonate use to controls following spinal fusion. Meta-analysis was performed using the random-effects model for heterogeneity. Radiographic outcome measures included fusion rates and risk of screw loosening, cage subsidence and vertebral fracture. Functional outcomes measures included Oswestry Disability Index and visual analog scale score for back and leg pain.Results: Bisphosphonate use was statistically suggestive of a higher fusion rate compared to controls (OR 2.2, 95% CI 0.87-5.56, p = 0.09). There was no difference in screw loosening rates between the bisphosphonate group and controls (OR 0.45, 95% CI 0.14-1.48, p = 0.19). However, bisphosphonate use was associated with decreased odds of cage subsidence and vertebral fractures compared to controls (cage subsidence: OR 0.29, 95% CI 0.11-0.75, p = 0.01; vertebral fracture: OR 0.18, 95% CI 0.07-0.48, p = 0.0007).Conclusion: Bisphosphonate use does not appear to impair successful lumbar fusion compared to controls. Additionally, bisphosphonate use was associated with decreased odds of cage subsidence and vertebral fractures compared to controls that had lumbar fusion. These slides can be retrieved under Electronic Supplementary Material. [ABSTRACT FROM AUTHOR]

Background: Single-position options for combined anterior and posterior fusion in the lumbar spine have been suggested to reduce the surgical time and improve the efficiency of operating room. Previous reports have focused on lateral decubitus single-position surgery. The goal of this study is to describe and evaluate the feasibility and safety of prone single-position extreme lateral interbody fusion (XLIF) with posterior fixation.Methods: Design Pilot prospective non-randomized controlled study. Seven patients who underwent prone single-position XLIF and posterior fixation were evaluated (Pro-XLIF). A control group (Std-XLIF) was composed of ten patients who underwent XLIF in lateral decubitus and posterior fixation in prone position. All patients underwent interbody XLIF fusion at one level and posterior procedures at one or more levels. Duration of surgery, blood loss, complications, X-ray use and clinical outcomes were recorded.Results: No major complications were observed in either group. Oswestry Disability Index, back pain and leg pain were improved in the Pro-XLIF group from 48.5, 7.7 and 8.5 to 14.5, 1.71 and 2.71, respectively, and in the Std-XLIF group from 50.8, 5.7 and 7.2 to 22.5, 3.7 and 2.5. The Pro-XLIF group had a longer time of preparation before incision (39 vs 26 min, ns), equal duration of the anterior procedure (65 vs 59 min, ns), shorter duration of surgery (133 vs 182 min, ns) and longer X-ray exposure time (102 vs 92 s, ns). The surgical technique is described.Conclusions: Prone single-position XLIF is feasible and safe. In this preliminary report, the results are comparable to the standard technique. These slides can be retrieved under Electronic Supplementary Material. [ABSTRACT FROM AUTHOR]

Purpose: To make a literature review on spinal stenosis recurrence after a first surgery and edit rules to avoid this complication.Methods: We conducted two separate PUBMED searches to evaluate the revision post-stenosis and degenerative scoliosis surgery using the terms: lumbar vertebrae/surgery, spinal stenosis, spine, scoliosis and reoperation. The resulting papers were categorized into three groups: (1) those that evaluated reoperation post-simple decompression; (2) those that evaluated spinal decompression and fusion for short (3 levels or less) or long (more than 3 levels) segment spinal fusion; and (3) those diagnosing the stenosis during the surgery.Results: (1) We found 11 relevant papers that only looked at revision spine surgery post-laminectomy for spinal stenosis. (2) We found 20 papers looked at reoperation post-laminectomy and fusion amongst which there were two papers specifically comparing long-segment (> 3 level) and short-segment (3 or less levels) fusions. (3) In the unspecified group, we found only one article. Fifteen articles were excluded as they were not specifically looking at our objective criteria for revision surgery. In regard to revision post-adult deformity surgery, we found 18 relevant articles.Conclusions: After this literature review and analysis of post-operative stenosis, it seems important to provide some advice to avoid revision surgeries more or less induced by the surgery. It looks interesting when performing simple decompression without fusion in the lumbar spine to analyse the risk of instability induced by the decompression and facet resection but also by a global balance analysis. Regarding pre-operative stenosis in a previously operated area, different causes may be evocated, like screw or cage malpositionning but also insufficient decompression which is a common cause. Intraoperatively, the use of neuromonitoring and intraoperative CT scan with navigation are useful tool in complex cases to avoid persisting stenosis. Pre-op analysis and planning are key parameters to decrease post-op problems. These slides can be retrieved under Electronic Supplementary Material. [ABSTRACT FROM AUTHOR]

Introduction: Revision surgery in spine tumor surgery can offer peculiar challenges given the severity of the majority of these lesions and the complexity of surgical procedures that are required.Materials and Methods and Results: Based on literature review and on personal experience, surgical site infection, cerebrospinal fluid leakage, tumor recurrence and hardware failures are some of the possible causes of surgical revision in this set of patients.Conclusions: The aim of this study is to evaluate the most frequent complications that can lead to revision in spine tumor patients, to provide suggestions on how to prevent these events and to offer reasonable strategies to properly plan and perform a revision surgery. These slides can be retrieved under Electronic Supplementary Material. [ABSTRACT FROM AUTHOR]

Purpose: Recurrent lumbar disc herniation is the most common complication after discectomy. Due to the altered anatomy with the presence of scar tissue, the surgical revision of already operated patients could be a surgical challenge.Methods: We describe the microsurgical revision technique step by step with the evaluation of our own clinical results in comparison with primary lumbar disc surgeries. The clinical data are based on a clinical register with 2576 recorded primary surgeries (PD) and 592 cases of revisions (RD) with 12- and 24-month follow-up (FU). The intraoperative dura lesion rates of the surgeries between 2016 and 2018 were recorded retrospectively. Data from 894 primary disc surgeries and 117 revisions were evaluated.Results: The ODI and the VAS for leg and back pain improved in both groups significantly with slightly inferior outcome of the revision group. The ODI improved from 46.3 (PD) and 45.9 (RD), respectively, to 12.6 (PD) and 22.9 (RD) at the 24-month FU. The VAS dropped down as well in both group [VAS back: 47.8 (PD) and 43.9 (RD) to 19.9 and 32.2 at the 24-month FU; VAS leg: 62.9 (PD) and 65.5 (RD) to 15.6 and 26.8 at the 24-month FU]. During the primary interventions, we observed 1.5% (11/894) and during revisions 7.7% (9/117) of dura lesions.Conclusions: There is no clear guideline for the surgical treatment of recurrent disc herniations. In most cases, a pure re-discectomy is sufficient and can be performed safely and effectively with the help of a microscope. These slides can be retrieved under Electronic Supplementary Material. [ABSTRACT FROM AUTHOR]

Purpose: Hyaluronic acid prevents tissue adhesion after different surgeries. Physical barriers and inflammatory regulation have been suggested to be involved in the mechanism of these clinical effects. However, the molecular mechanism by which hyaluronic acid prevents epidural adhesion has not yet been reported.Methods: In the current in vivo studies, we investigated cross-linked hyaluronic acid gel in the regulation of scar gene expression, the accumulation of fibroblasts in scar tissue, and the prevention of epidural adhesion. The effect of cross-linked hyaluronic acid gel on the secretion of inflammatory factors was observed in vitro. In addition, to ensure the accuracy and reliability of the in vivo gene expression results, we used a cell model to detect the target genes in vitro.Results: The expression levels of TGFβ1 and COL1A1 mRNA were decreased in the cross-linked hyaluronic acid gel-treated group, and the protein expression of levels TGFβ1 and COL1A1 were also reduced, as detected by Western blotting in vitro and in vivo (P < 0.05). Histomorphometry results demonstrated that the number of fibroblasts in the experimental group was significantly lower than that in the control group 2 weeks postoperatively. Micro-CT scans showed that the cross-linked hyaluronic acid gel could reduce adhesion in the epidural space after laminectomy. Additionally, the cross-linked hyaluronic acid gel could inhibit IL-6 secretion.Conclusions: These results indicate that cross-linked hyaluronic acid gel can prevent epidural adhesion by inhibiting inflammatory factors, such as IL-6, and downregulating TGFβ1 and COL1A1 mRNA expression. These slides can be retrieved under Electronic Supplementary Material. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to evaluate the efficacy of decompression surgery alone for patients with intolerable low back pain.Methods: We retrospectively identified 222 patients who underwent spinal decompression without fusion surgery who had substantial preoperative low back pain (preoperative numerical rating scale score ≥ 5). Their clinical outcomes were assessed using the numerical rating scale and the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) preoperatively and at 3 months and 1 year after surgery.Results: At 3 months and 1 year after surgery compared with baseline, there was a significant improvement in the overall mean numerical rating scale scores for low back pain (baseline = 6.8, 3 months = 2.1, 1 year = 2.7), leg pain (6.8, 2.1, 2.7), and leg numbness (6.4, 2.9, 3.2) (P < 0.05). The efficacy rate assessed by JOABPEQ was 68.1% for pain-related disorders, 47.0% for lumbar spine dysfunction, 63.3% for walking ability, 48.2% for social life dysfunction, and 21.6% for psychological disorders. When patients were classified into three groups depending on their degree of leg pain (mild, moderate, and severe), there was no significant difference in the efficacy rate between the three groups.Conclusion: Decompression surgery can improve low back pain, regardless of the degree of preoperative leg pain, but the average score for LBP and leg pain slightly worsened between 3 months and 1 year after surgery. These slides can be retrieved under Electronic Supplementary Material. [ABSTRACT FROM AUTHOR]

Purpose: Choosing an optimal distal fusion level for adult spinal deformity (ASD) is still controversial. To compare the radiographic and clinical outcomes of distal fusion to L5 versus the sacrum in ASD, we conducted a meta-analysis.Methods: Relevant studies on long fusion terminating at L5 or the sacrum in ASD were retrieved from the PubMed, Embase, Cochrane, and Google Scholar databases. Then, studies were manually selected for inclusion based on predefined criteria. The meta-analysis was performed by RevMan 5.3.Results: Eleven retrospective studies with 1211 patients were included in meta-analysis. No significant difference was found in overall complication rate (95% CI 0.60 to 1.30) and revision rate (95% CI 0.59 to 1.99) between fusion to L5 group (L group) and fusion to the sacrum group (S group). Significant lower rate of pseudarthrosis and implant-related complications (95% CI 0.29 to 0.64) as well as proximal adjacent segment disease (95% CI 0.35 to 0.92) was found in L group. Patients in S group obtained a better correction of lumbar lordosis (95% CI - 7.85 to - 0.38) and less loss of sagittal balance (95% CI - 1.80 to - 0.50).Conclusion: Our meta-analysis suggested that long fusion terminating at L5 or the sacrum was similar in scoliosis correction, overall complication rate, revision rate, and improvement in pain and disability. However, fusion to L5 had advantages in lower rate of pseudarthrosis, implant-related complications, and proximal adjacent segment disease, while fusion to the sacrum had advantages in the restoration of lumbar lordosis, maintenance of sagittal balance, and absence of distal adjacent segment disease. These slides can be retrieved under Electronic Supplementary Material. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effect on the spinal canal at the treated and adjacent level(s), in patients treated for lumbar spinal stenosis (LSS) with percutaneous interspinous process device (IPD) Aperius™ or open decompressive surgery (ODS), using axial loading of the spine during MRI (alMRI).Materials: Nineteen LSS patients (mean age 67 years, range 49-78) treated with IPDs in 29 spine levels and 13 LSS patients (mean age 63 years, range 46-76) operated with ODS in 22 spine levels were examined with alMRI pre- and 3 months postoperatively. Radiological effects were evaluated by measuring the dural sac cross-sectional area (DSCSA) and by morphological grading of nerve root affection.Results: For the IPD group, no DSCSA increase was observed at the operated level (p = 0.42); however, a decrease was observed in adjacent levels (p = 0.05). No effect was seen regarding morphological grading (operated level: p = 0.71/adjacent level: p = 0.94). For the ODS group, beneficial effects were seen for the operated level, both regarding DSCSA (p < 0.001) and for morphological grading (p < 0.0001). No changes were seen for adjacent levels (DSCSA; p = 0.47/morphological grading: p = 0.95). Postoperatively, a significant difference between the groups existed at the operated level regarding both evaluated parameters (p < 0.003).Conclusions: With the spine imaged in an axial loaded position, no significant radiological effects of an IPD could be detected postoperatively at the treated level, while increased DSCSA was displayed for the ODS group. In addition, reduced DSCSA in adjacent levels was detected for the IPD group. Thus, the beneficial effects of IPD implants on the spinal canal must be questioned. These slides can be retrieved under Electronic Supplementary Material. [ABSTRACT FROM AUTHOR]