Patient-Reported and Clinical Outcomes of Surgically Treated Patients With Symptomatic Spinal Metastases: Results From Epidemiology, Process, and Outcomes of Spine Oncology (EPOSO), a Prospective, Multi-Institutional and International Study.

BACKGROUND AND OBJECTIVES: The palliative impact of spine surgery for metastatic disease is evolving with improvements in surgical technique and multidisciplinary cancer care. The goal of this study was to prospectively evaluate long-term clinical outcomes including health-related quality-of-life (HRQOL) measures, using spine cancer-specific patient-reported-outcome (PRO) measures, in patients with symptomatic spinal metastases who underwent surgical management. METHODS: The Epidemiology, Process, and Outcomes of Spine Oncology (EPOSO, ClinicalTrials.gov identifier: NCT01825161) trial is a prospective-observational cohort study that included 10 specialist centers in North America and Europe. Patients aged 18 to 75 years who underwent surgery for spinal metastases were included. Prospective assessments included both spine tumor-specific and generic PRO tools which were collected for a minimum of 2 years post-treatment or until death. RESULTS: Two hundred and eighty patients (51.8% female, mean age 57.9 years) were included. At presentation, the mean Charlson Comorbidity Index was 6.0, 35.7% had neurological deficits as defined by the American Spinal Cord Injury Association scores, 47.2% had high-grade epidural spinal cord compression (2-3), and 89.6% had impending or frank instability as measured by a Spinal Instability Neoplastic Score of ≥7. The most common primary tumor sites were breast (20.2%), lung (18.8%), kidney (16.2%), and prostate (6.5%). The median overall survival postsurgery was 501 days, and the 2-year progression-free-survival rate was 38.4%. Compared with baseline, significant and durable improvements in HRQOL were observed at the 6-week, 12-week, 26-week, 1-year, and 2-year follow-up assessments from a battery of PRO questionnaires including the spine cancer-specific, validated, Spine Oncology Study Group Outcomes Questionnaire v2.0, the Short Form 36 version 2, EuroQol-5 Dimension (3L), and pain numerical rating scale score. CONCLUSION: Multi-institutional, prospective-outcomes data confirm that surgical decompression and/or stabilization provides meaningful and durable improvements in multiple HRQOL domains, including spine-specific outcomes based on the Spine Oncology Study Group Outcomes Questionnaire v2.0, for patients with metastatic spine disease.

Gender and Sex Differences in Health-related Quality of Life, Clinical Outcomes and Survival after Treatment of Metastatic Spine Disease.

STUDY DESIGN: Retrospective review of prospective, multicenter and international cohort study. OBJECTIVE: To describe the effect of gender on HRQoL, clinical outcomes and survival for patients with spinal metastases treated with either surgery and/or radiation. SUMMARY OF BACKGROUND DATA: Gender differences in health-related outcomes are demonstrated in numerous studies, with women experiencing worse outcomes and receiving lower standards of care than men, however, the influence that gender has on low health-related quality of life (HRQoL) and clinical outcomes after spine surgery remains unclear. METHODS: Patient demographic data, overall survival, treatment details, perioperative complications, and HRQoL measures including EQ-5D, pain NRS, the short form 36 version 2 (SF-36v2) and the Spine Oncology Study Group Outcomes Questionnaire (SOSGOQ2.0) were reviewed. Patients were stratified by sex, and a separate sensitivity analysis that excluded gender-specific cancers (i.e., breast, prostate, etc.) was performed. RESULTS: The study cohort included 207 female and 183 male patients, with age, smoking status, and site of primary cancer being significantly different between the two cohorts (P<0.001). Both males and females experienced significantly improved SOSGOQ2.0, EQ-5D, and pain NRS scores at all study time points from baseline (P<0.001). Upon sensitivity analysis, (gender-specific cancers removed from analysis), the significant improvement in SOSGOQ physical, mental, and social subdomains and on SF-36 domains disappeared for females. Males experienced higher rates of postoperative complications. Kaplan-Meier survival analysis of both the overall and sensitivity analysis cohorts showed females lived longer than males after treatment (P=0.001 and 0.043, respectively). CONCLUSION: Both males and females experienced significantly improved HRQoL scores after treatment, but females demonstrated longer survival and a lower complication rate. This study suggests that gender may be a prognostic factor in survival and clinical outcomes for patients undergoing treatment for spine metastases and should be taken into consideration when counseling patients accordingly.

Comparison of anterior column reconstruction techniques after en bloc spondylectomy: a finite element study.

Total en bloc spondylectomy (TES) effectively treats spinal tumors. The surgery requires a vertebral body replacement (VBR), for which several solutions were developed, whereas the biomechanical differences between these devices still need to be completely understood. This study aimed to compare a femur graft, a polyetheretherketone implant (PEEK-IMP-C), a titan mesh cage (MESH-C), and a polymethylmethacrylate replacement (PMMA-C) using a finite element model of the lumbar spine after a TES of L3. Several biomechanical parameters (rotational stiffness, segmental range of motion (ROM), and von Mises stress) were assessed to compare the VBRs. All models provided adequate initial stability by increasing the rotational stiffness and decreasing the ROM between L2 and L4. The PMMA-C had the highest stiffness for flexion-extension, lateral bending, and axial rotation (215%, 216%, and 170% of intact model), and it had the lowest segmental ROM in the instrumented segment (0.2°, 0.5°, and 0.7°, respectively). Maximum endplate stress was similar for PMMA-C and PEEK-IMP-C but lower for both compared to MESH-C across all loading directions. These results suggest that PMMA-C had similar or better primary spinal stability than other VBRs, which may be related to the larger contact surface and the potential to adapt to the patient's anatomy.

Complication Pattern of Sacral Primary Tumor Resection: A Study on the Risk Factors of Surgical Site Infection and Bowel or Bladder Dysfunction and Their Associations with Length of Hospital Stay.

STUDY DESIGN: Retrospective open cohort study. PURPOSE: The current study aimed to explore the pattern of complications after primary sacral tumor resection, to investigate the possible effect of several perioperative parameters on the development of complications, and to identify which complications are associated with the length of hospital stay (LOS). OVERVIEW OF LITERATURE: Primary sacral tumor (pST) resection is associated with a high complication rate. However, the number of studies on these complications and their effect on LOS is limited. METHODS: The clinical data of 140 patients with pST surgeries and 106 subsequent patients with local recurrence surgeries in four subgroups (index surgery, local recurrence surgery, malignant, and benign tumor) were prospectively collected and analyzed. The prognostic value of several perioperative factors on the development of surgical site infection (SSI), bowel and bladder dysfunction (BBD), and LOS was investigated using the logistic and linear regression models. RESULTS: The overall complication rates were 61.2% after index surgeries and 50.9% after local recurrence surgeries. The most frequent complications were SSI, vegetative dysfunction, urinary tract infections, and neurological deterioration. Age >55 years, malignant tumors, and red blood cell transfusion had a predictive effect on the development of SSI in the logistic model (p<0.01, R2=0.43). Bilateral S2 or S3 resection commonly caused postoperative BBD (chi-square test=62.5, degrees of freedom=4, p<0.001). In the multiple linear regression model, wound dehiscence, BBD, systemic and urinary tract infection, cerebrospinal fluid leak, and neurologic deterioration were associated with a significantly long LOS (p<0.01, R2=0.62). CONCLUSIONS: Surgical resection of pSTs has a high complication rate. Its common complications are SSI and BBD, both of which can have a significant influence on global therapeutic outcome. Malignant tumor diagnosis, old age, and red blood cell transfusion can remarkably increase the risk of SSI. Further, the development of BBD is significantly associated with the number of resected sacral nerve roots. By decreasing perioperative complications, LOS can decrease significantly.

Complication Pattern After Percutaneous Cement Discoplasty: Identification of Factors Influencing Reoperation and Length of Hospital Stay.

OBJECTIVE: Percutaneous cement discoplasty (PCD) was introduced to treat symptomatic vertical instability of the lumbar spine in a minimally invasive way. The aim of the present study was to analyze the complication pattern after PCD and to identify factors that predict the chance of cement leakage, reoperation, and length of hospital stay (LOS). METHODS: patients were treated with PCD within the study period. Clinical features and complications were analyzed by applying descriptive statistics, whereas perioperative factors predictive of cement leakage, reoperation, and LOS were identified by regression models. RESULTS: Cement leakage rate was 30.4% in the total cohort; however, only fifth of them were symptomatic. Cement leakage itself did not have a significant influence on clinical outcome. Other complications and nonsurgical adverse events were registered only in 2.0% of cases. Age, subcutaneous fat tissue thickness, low viscosity cement, lower level of surgeon's experience and the number of operated levels were identified as risk factors of cement leakage (P < 0.01; c-index = 0.836). Type of procedure, Charlson comorbidity score, reoperation, and nonsurgical adverse events significantly increased the LOS (P < 0.01). Cement leakage, early surgical practice, and increased subcutaneous fat tissue thickness were risk factors for reoperation (P < 0.01; c-index = 0.72). CONCLUSIONS: PCD is a relatively safe and effective procedure for treating spinal instability caused by advanced-stage disc degeneration characterized by vacuum phenomenon. Cement leakage is not uncommon but is only a radiologic complication without clinical consequences in most cases. On the other hand, it can increase the LOS and is a significant risk factor for reoperation.

Can semirigid fixation of the rostral instrumented segments prevent proximal junctional kyphosis in the case of long thoracolumbar fusions? A finite element study.

OBJECTIVE: Proximal junctional kyphosis (PJK) is a relatively common complication following long instrumented posterior spinal fusion. Although several risk factors have been identified in the literature, previous biomechanical studies suggest that one of the leading causes is the sudden change in mobility between the instrumented and noninstrumented segments. The current study aims to assess the biomechanical effect of 1 rigid and 2 semirigid fixation techniques (SFTs) on developing PJK. METHODS: Four T7-L5 finite element (FE) models were developed: 1) intact spine; 2) 5.5-mm titanium rod from T8 to L5 (titanium rod fixation [TRF]); 3) multiple rods from T8 to T9 connected with titanium rod from T9 to L5 (multiple-rod fixation [MRF]); and 4) polyetheretherketone rod from T8 to T9 connected with titanium rod from T9 to L5 (PEEK rod fixation [PRF]). A modified multidirectional hybrid test protocol was used. First, a pure bending moment of 5 Nm was applied to measure the intervertebral rotation angles. Second, the TRF technique's displacement from the first loading step was applied to the instrumented FE models to compare the pedicle screw stress values in the upper instrumented vertebra (UIV). RESULTS: In the load-controlled step, at the upper instrumented segment, the intervertebral rotation values relative to TRF increased by 46.8% and 99.2% for flexion, by 43.2% and 87.7% for extension, by 90.1% and 137% for lateral bending, and by 407.1% and 585.2% for axial rotation, in the case of MRF and PRF, respectively. In the displacement-controlled step, maximum pedicle screw stress values at the UIV level were highest in the case of TRF (37.26 MPa, 42.13 MPa, 44.4 MPa, and 44.59 MPa for flexion, extension, lateral bending, and axial rotation, respectively). Compared to TRF, in the case of MRF and PRF, the screw stress values were reduced by 17.3% and 27.7% for flexion, by 26.6% and 36.7% for extension, by 6.8% and 34.3% for lateral bending, and by 49.1% and 59.8% for axial rotation, respectively. CONCLUSIONS: FE analysis has shown that the SFTs increase the mobility at the upper instrumented segment and therefore provide a more gradual transition in motion between the instrumented and rostral noninstrumented segments of the spine. In addition, SFTs decrease the screw loads at the UIV level and hence could help reduce the risk for PJK. However, further investigations are recommended to evaluate the long-term clinical usefulness of these techniques.

Outcomes of Surgical Treatment for Extradural Benign Primary Spinal Tumors in Patients Younger than 25 Years: An Ambispective International Multicenter Study.

Extradural primary spinal tumors were retrospectively analyzed from a prospective database of 1495 cases. All subjects with benign primary tumors under the age of 25 years, who were enrolled between 1990 and 2012 (Median FU was 2.4 years), were identified. Patient- and case-related characteristics were collected and statistically analyzed. Results: 161 patients (66f;95m; age 17.0 ± 4.7 years at time of diagnosis) were identified. The most common tumors were osteoblastomas n = 53 (32.9%), osteoid osteomas n = 45 (28.0%), and aneurysmal bone cysts n = 32 (19.9%). The tumor grade, according to the Enneking Classification S1/S2/S3, was 14/73/74 (8.7/45.3/46.0%), respectively. Tumor-related pain was present in 156 (96.9%) patients. Diagnosis was achieved by biopsies in 2/3 of the cases. Spinal fixation was used in >50% of the cases. Resection was Enneking appropriate in n = 100 (62.1%) of cases. Local recurrence occurred in 21 (13.1%) patients. Two patients died within a 10-year follow-up period. Conclusion: This is one of the largest international multicenter cohorts of young patients surgically treated for benign spinal tumors. The heterogenic young patient cohort presented at a mid-term follow-up without a correlation between the grade of aggressiveness in resection and local recurrence rates. Further prospective data are required to identify prognostic factors that determine oncological and functional outcomes for young patients suffering from these rare tumors.

Extradural Primary Malignant Spinal Tumors in a Population Younger than 25 Years: An Ambispective International Multicenter Study on Onco-Surgical Outcomes.

Extradural malignant primary spinal tumors are rare and outcome data, especially for younger patients, is limited. In a worldwide (11 centers) study (Predictors of Mortality and Morbidity in the Surgical Management of Primary Tumors of the Spine study; ClinicalTrials.gov Identifier NCT01643174) by the AO Spine Knowledge Forum Tumor, patients surgically treated for primary tumors of the spine between 1992 and 2012, were retrospectively analyzed from a prospective database of their medical history. Medical history, tumor characteristics, diagnostics, treatments, cross-sectional survival, and local recurrences were analyzed. Sixty-eight cases (32 f; 36 m), at an average age of 18.6 ± 4.7 years at the time of diagnosis, were identified (median follow-up 2.9 years). The most common entities were Ewing's sarcoma (42.6%). Of the patients, 28% had undergone previous spine tumor surgery in another center (84% with intralesional margins). Resection was considered "Enneking appropriate" (EA) in 47.8% of the cases. Of the patients, 77.9% underwent chemotherapy and 50% radiotherapy. A local recurrence occurred in 36.4%. Over a third of patients died within a 10-year follow-up period. Kaplan-Meier-analysis demonstrated statistically significant overall survival (p = 0.007) and local recurrence rates (p = 0.042) for tumors treated with EA surgery versus Enneking inappropriate surgery. Aggressive resection of extradural primary malignant spinal tumors combined with adjuvant therapy reveals low local recurrence rates and better outcomes overall in younger patients.

Correlation Between the Spinal Instability Neoplastic Score (SINS) and Patient Reported Outcomes.

STUDY DESIGN: International multicenter prospective observational cohort study on patients undergoing radiation +/- surgical intervention for the treatment of symptomatic spinal metastases. OBJECTIVES: To investigate the association between the total Spinal Instability Neoplastic Score (SINS), individual SINS components and PROs. METHODS: Data regarding patient demographics, diagnostics, treatment, and PROs (SF-36, SOSGOQ, EQ-5D) was collected at baseline, 6 weeks, and 12 weeks post-treatment. The SINS was assessed using routine diagnostic imaging. The association between SINS, PRO at baseline and change in PROs was examined with the Spearmans rank test. RESULTS: A total of 307 patients, including 174 patients who underwent surgery+/- radiotherapy and 133 patients who underwent radiotherapy were eligible for analyses. In the surgery+/- radiotherapy group, 18 (10.3%) patients with SINS score between 0-6, 118 (67.8%) with a SINS between 7-12 and 38 (21.8%) with a SINS between 13-18, as compared to 55 (41.4%) SINS 0-6, 71(53.4%) SINS 7-12 and 7 (5.2%) SINS 13-18 in the radiotherapy alone group. At baseline, the total SINS and the presence of mechanical pain was significantly associated with the SOSGOQ pain domain (r = -0.519, P < 0.001) and the NRS pain score (r = 0.445, P < 0.001) for all patients. The presence of mechanical pain demonstrated to be moderately associated with a positive change in PROs at 12 weeks post-treatment. CONCLUSION: Spinal instability, as defined by the SINS, was significantly correlated with PROs at baseline and change in PROs post-treatment. Mechanical pain, as a single SINS component, showed the highest correlations with PROs.

Impact of Patient-specific Factors and Spinopelvic Alignment on the Development of Adjacent Segment Degeneration After Short-segment Lumbar Fusion.

STUDY DESIGN: Prospective cross-sectional cohort study. OBJECTIVES: The main purpose of this study was to evaluate the association between demographical, surgery-related and morphologic parameters, and the development or progress of adjacent segment degeneration (ASD) after short-segment lumbar fusions. SUMMARY OF BACKGROUND DATA: ASD is a major long-term complication after lumbar fusions. Possible risk factors are related to the patients' demographics, spinopelvic anatomy, or preoperative lumbar intervertebral disk conditions, but the role of these parameters is still not clear. METHODS: A prospective cross-sectional study of 100 patients who underwent 1- or 2-level open lumbar transforaminal interbody fusions due to a lumbar degenerative pathology was conducted. Demographical, radiologic findings, and magnetic resonance imaging features were analyzed to identify factors associated with ASD in 5-year follow-up. RESULTS: ASD patients showed higher level of pain ( P =0.004) and disability ( P =0.020) at follow-up. In univariate analysis, older age ( P =0.007), upper-level lumbar fusion ( P =0.007), lower L4-S1 lordosis ( P =0.039), pelvic incidence-lumbar lordosis mismatch ( P =0.021), Pfirrmann grade III or higher disk degeneration ( P =0.002), and the presence of disk bulge/protrusion ( P =0.007) were associated with ASD. In multivariate analysis, the presence of major degenerative sign (disk degeneration and/or disk bulge) was the significant predictor for developing ASD (odds ratio: 3.85, P =0.006). CONCLUSION: By examining the role of different patient- and procedure-specific factors, we found that preoperative major degenerative signs at the adjacent segment increase the risk of ASD causing significantly worse outcome after short-segment lumbar fusion. On the basis of our results, adjacent disk conditions should be considered carefully during surgical planning.

Biomechanical consequences of cement discoplasty: An in vitro study on thoraco-lumbar human spines.

With the ageing of the population, there is an increasing need for minimally invasive spine surgeries to relieve pain and improve quality of life. Percutaneous Cement Discoplasty is a minimally invasive technique to treat advanced disc degeneration, including vacuum phenomenon. The present study aimed to develop an in vitro model of percutaneous cement discoplasty to investigate its consequences on the spine biomechanics in comparison with the degenerated condition. Human spinal segments (n = 27) were tested at 50% body weight in flexion and extension. Posterior disc height, range of motion, segment stiffness, and strains were measured using Digital Image Correlation. The cement distribution was also studied on CT scans. As main result, percutaneous cement discoplasty restored the posterior disc height by 41% for flexion and 35% for extension. Range of motion was significantly reduced only in flexion by 27%, and stiffness increased accordingly. The injected cement volume was 4.56 ± 1.78 ml (mean ± SD). Some specimens (n = 7) exhibited cement perforation of one endplate. The thickness of the cement mass moderately correlated with the posterior disc height and range of motion with different trends for flexions vs. extension. Finally, extreme strains on the discs were reduced by percutaneous cement discoplasty, with modified patterns of the distribution. To conclude, this study supported clinical observations in term of recovered disc height close to the foramen, while percutaneous cement discoplasty helped stabilize the spine in flexion and did not increase the risk of tissue damage in the annulus.

Potential molecular mechanism in self-renewal is associated with miRNA dysregulation in sacral chordoma - A next-generation RNA sequencing study.

Background: Chordoma, the most frequent malignant primary spinal neoplasm, characterized by a high rate of recurrence, is an orphan disease where the clarification of the molecular oncogenesis would be crucial to developing new, effective therapies. Dysregulated expression of non-coding RNAs, especially microRNAs (miRNA) has a significant role in cancer development. Methods: Next-generation RNA sequencing (NGS) was used for the combinatorial analysis of mRNA-miRNA gene expression profiles in sacral chordoma and nucleus pulposus samples. Advanced bioinformatics workflow was applied to the data to predict miRNA-mRNA regulatory networks with altered activity in chordoma. Results: A large set of significantly dysregulated miRNAs in chordoma and their differentially expressed target genes have been identified. Several molecular pathways related to tumorigenesis and the modulation of the immune system are predicted to be dysregulated due to aberrant miRNA expression in chordoma. We identified a gene set including key regulators of the Hippo pathway, which is targeted by differently expressed miRNAs, and validated their altered expression by RT-qPCR. These newly identified miRNA/RNA interactions are predicted to have a role in the self-renewal process of chordoma stem cells, which might sustain the high rate of recurrence for this tumor. Conclusions: Our results can significantly contribute to the designation of possible targets for the development of anti-chordoma therapies.

Genetic variants of interleukin 1B and 6 are associated with clinical outcome of surgically treated lumbar degenerative disc disease.

BACKGROUND: Successfully surgically treating degenerative disc diseases can be challenging to the spine surgeons, the long-term outcome relies on both the physical and mental status of the patient before and after treatment. Numerous studies underlined the role of inflammatory cytokines - like interleukin 1B and 6 - in the development of chronic diseases such as failed back surgery syndrome (FBSS) and major depressive disorder (MDD) which alter the outcome after spinal surgery. Our aim was to evaluate the associations of IL6 and IL1B gene polymorphisms with the long-term outcome of degenerative lumbar spine surgeries. METHODS: An international genetical database (GENODISC) was combined with our institute's clinical database to create a large pool with long term follow up data. Altogether 431 patient's data were analysed. Patient reported outcome measures and surgical outcome was investigated in association with IL1B and IL6 SNPs with the help of 'SNPassoc' R genome wide association package. RESULTS: Interleukin 1B variants analysis confirmed association with improvement of pain after surgery on individual SNP level and on haplotype level, moreover relationship with patient reported outcome and preoperative level of depression was found on individual SNP level. IL6 variants were associated with preoperative depression, somatization and with subsequent surgery. CONCLUSION: Understanding the complexity of spinal surgery patients' long-term well-being is crucial in effectively treating chronic debilitating somatic diseases and the associated mental illnesses. Further studies should investigate more comprehensively the linkage of chronic physical and mental illnesses focusing on their simultaneous treatment.

Critical Review of the State-of-the-Art on Lumbar Percutaneous Cement Discoplasty.

Interbody fusion is the gold standard surgery to treat lumbar disc degeneration disease but can be a high-risk procedure in elderly and polymorbid patients. Percutaneous Cement Discoplasty (PCD) is a minimally invasive technique developed to treat advanced stage of disc degeneration exhibiting a vacuum phenomenon. A patient-specific stand-alone spacer is created by filling the disc with polymethylmethacrylate cement, allowing to recover the disc height and improve the patient's conditions. As it has recently been introduced in the lumbar spine, this review aims to present a transversal state-of-the-art of the surgery from its clinical practice and outcome to biomechanical and engineering topics. The literature was searched across multiple databases using predefined keywords over no limited period of time. Papers about vertebroplasty were excluded. Among 466 identified papers, the relevant ones included twelve clinical papers reporting the variations of the surgical technique, follow-up and complications, four papers reporting biomechanical ex vivo and numerical tests, and four letters related to published clinical papers. Papers presenting the operative practice are reported, as well as follow-ups up to four years. The papers found, consistently reported that PCD significantly improved the clinical status of the patients and maintained it after two years. Spine alignment was impacted by PCD: the sacral slope was significantly reduced, and disc height increased. The foramen opening correlated to the volume of injected cement. Substitutes to the acrylic cement exhibited better osteointegration and mechanical properties closer to bone tissue. Finally, limitations and risks of the surgery are discussed as well as potential improvements such as the development of new filling materials with better mechanical properties and biological integration or the investigation of the inner disc.

Steroids in the Management of Preoperative Neurological Deficits in Metastatic Spine Disease: Results From the EPOSO Study.

OBJECTIVE: Patients presenting with neurological deficit secondary to metastatic epidural spinal cord compression (MESCC) are often treated with surgery in combination with high-dose corticosteroids. Despite steroids being commonly used, the evidence regarding the effect of corticosteroids on patient outcomes is limited. The objective of this study was to describe the effect of corticosteroid use on preoperative neurological function in patients with MESCC. METHODS: Patients who underwent surgery between August 2013 and February 2017 for the treatment of spinal metastases and received steroids to prevent neurologic deficits were included. Data regarding demographics, diagnosis, treatment, neurological function, adverse events, health-related quality of life, and survival were extracted from an international multicenter prospective cohort. RESULTS: A total of 30 patients treated surgically and receiving steroids at baseline were identified. Patients had a mean age of 58.2 years (standard deviation, 11.2 years) at time of surgery. Preoperatively, 50% of the patients experienced deterioration of neurological function, while in 30% neurological function was stable and 20% improved in neurological function. Lengthier steroid use did not correlate with improved or stabilized neurological function. Postoperative adverse events were observed in 18 patients (60%). Patients that stabilized or improved neurologically after steroid use showed a trend towards improved survival at 3- and 24-month postsurgery. CONCLUSION: This study described the effect of steroids on preoperative neurological function in patients with MESCC. Stabilization or improvement of preoperative neurological function occurred in 50% of the patients.

Stability Evaluation of Different Oblique Lumbar Interbody Fusion Constructs in Normal and Osteoporotic Condition - A Finite Element Based Study.

Introduction: In developed countries, the age structure of the population is currently undergoing an upward shift, resulting a decrease in general bone quality and surgical durability. Over the past decade, oblique lumbar interbody fusion (OLIF) has been globally accepted as a minimally invasive surgical technique. There are several stabilization options available for OLIF cage fixation such as self-anchored stand-alone (SSA), lateral plate-screw (LPS), and bilateral pedicle screw (BPS) systems. The constructs' stability are crucial for the immediate and long-term success of the surgery. The aim of this study is to investigate the biomechanical effect of the aforementioned constructs, using finite element analysis with different bone qualities (osteoporotic and normal). Method: A bi-segmental (L2-L4) finite element (FE) model was created, using a CT scan of a 24-year-old healthy male. After the FE model validation, CAD geometries of the implants were inserted into the L3-L4 motion segment during a virtual surgery. For the simulations, a 150 N follower load was applied on the models, then 10 Nm of torque was used in six general directions (flexion, extension, right/left bending, and right/left rotation), with different bone material properties. Results: The smallest segmental (L3-L4) ROM (range of motion) was observed in the BPS system, except for right bending. Osteoporosis increased ROMs in all constructs, especially in the LPS system (right bending increase: 140.26%). Osteoporosis also increased the caudal displacement of the implanted cage in all models (healthy bone: 0.06 ± 0.03 mm, osteoporosis: 0.106 ± 0.07 mm), particularly with right bending, where the displacement doubled in SSA and LPS constructs. The displacement of the screws inside the L4 vertebra increased by 59% on average (59.33 ± 21.53%) due to osteoporosis (100% in LPS, rotation). BPS-L4 screw displacements were the least affected by osteoporosis. Conclusions: The investigated constructs provide different levels of stability to the spine depending on the quality of the bone, which can affect the outcome of the surgery. In our model, the BPS system was found to be the most stable construct in osteoporosis. The presented model, after further development, has the potential to help the surgeon in planning a particular spinal surgery by adjusting the stabilization type to the patient's bone quality.

Calculating Utilities From the Spine Oncology Study Group Outcomes Questionnaire: A Necessity for Economic and Decision Analysis.

STUDY DESIGN: General population utility valuation study. OBJECTIVE: The aim of this study was to develop a technique for calculating utilities from the Spine Oncology Study Group Outcomes Questionnaire v2.0 (SOSGOQ2.0). SUMMARY OF BACKGROUND DATA: The ability to calculate quality-adjusted life-years (QALYs) for metastatic spine disease would enhance treatment decision-making and facilitate economic analysis. QALYs are calculated using utilities. METHODS: Using a hybrid concept-retention and factorial analysis shortening approach, we first shortened the SOSGOQ2.0 to eight items (SOSGOQ-8D). This was done to lessen the cognitive burden of the utility valuation exercise. A general population sample of 2730 adults was then asked to evaluate 12 choice sets based on SOSGOQ-8D health states in a Discrete Choice Experiment. A utility scoring rubric was then developed using a mixed multinomial-logit regression model. RESULTS: We were able to reduce the SOSGOQ2.0 to an SOSGOQ-8D with a mean error of 0.003 and mean absolute error of 3.078 compared to the full questionnaire. The regression model demonstrated good predictive performance and was used to develop a utility scoring rubric. Regression results revealed that participants did not regard all SOSGOQ-8D items as equally important. CONCLUSION: We provide a simple technique for converting the SOSGOQ2.0 to utilities. The ability to evaluate QALYs in metastatic spine disease will facilitate economic analysis and patient counseling. We also quantify the importance of individual SOSGOQ-8D items. Clinicians should heed these findings and offer treatments that maximize function in the most important items.Level of Evidence: 3.

Complicated Postoperative Flat Back Deformity Correction With the Aid of Virtual and 3D Printed Anatomical Models: Case Report.

Introduction: The number of patients with iatrogenic spinal deformities is increasing due to the increase in instrumented spinal surgeries globally. Correcting a deformity could be challenging due to the complex anatomical and geometrical irregularities caused by previous surgeries and spine degeneration. Virtual and 3D printed models have the potential to illuminate the unique and complex anatomical-geometrical problems found in these patients. Case Presentation: We present a case report with 6-months follow-up (FU) of a 71 year old female patient with severe sagittal and coronal malalignment due to repetitive discectomy, decompression, laminectomy, and stabilization surgeries over the last 39 years. The patient suffered from severe low back pain (VAS = 9, ODI = 80). Deformity correction by performing asymmetric 3-column pedicle subtraction osteotomy (PSO) and stabilization were decided as the required surgical treatment. To better understand the complex anatomical condition, a patient-specific virtual geometry was defined by segmentation based on the preoperative CT. The geometrical accuracy was tested using the Dice Similarity Index (DSI). A complex 3D virtual plan was created for the surgery from the segmented geometry in addition to a 3D printed model. Discussion: The segmentation process provided a highly accurate geometry (L1 to S2) with a DSI value of 0.92. The virtual model was shared in the internal clinical database in 3DPDF format. The printed physical model was used in the preoperative planning phase, patient education/communication and during the surgery. The surgery was performed successfully, and no complications were registered. The measured change in the sagittal vertical axis was 7 cm, in the coronal plane the distance between the C7 plumb line and the central sacral vertical line was reduced by 4 cm. A 30° correction was achieved for the lumbar lordosis due to the PSO at the L4 vertebra. The patient ODI was reduced to 20 points at the 6-months FU. Conclusions: The printed physical model was considered advantageous by the surgical team in the pre-surgical phase and during the surgery as well. The model was able to simplify the geometrical problems and potentially improve the outcome of the surgery by preventing complications and reducing surgical time.

Feasibility of achieving planned surgical margins in primary spine tumor: a PTRON study.

OBJECTIVE: Oncological resection of primary spine tumors is associated with lower recurrence rates. However, even in the most experienced hands, the execution of a meticulously drafted plan sometimes fails. The objectives of this study were to determine how successful surgical teams are at achieving planned surgical margins and how successful surgeons are in intraoperatively assessing tumor margins. The secondary objective was to identify factors associated with successful execution of planned resection. METHODS: The Primary Tumor Research and Outcomes Network (PTRON) is a multicenter international prospective registry for the management of primary tumors of the spine. Using this registry, the authors compared 1) the planned surgical margin and 2) the intraoperative assessment of the margin by the surgeon with the postoperative assessment of the margin by the pathologist. Univariate analysis was used to assess whether factors such as histology, size, location, previous radiotherapy, and revision surgery were associated with successful execution of the planned margins. RESULTS: Three hundred patients were included. The surgical plan was successfully achieved in 224 (74.7%) patients. The surgeon correctly assessed the intraoperative margins, as reported in the final assessment by the pathologist, in 239 (79.7%) patients. On univariate analysis, no factor had a statistically significant influence on successful achievement of planned margins. CONCLUSIONS: In high-volume cancer centers around the world, planned surgical margins can be achieved in approximately 75% of cases. The morbidity of the proposed intervention must be balanced with the expected success rate in order to optimize patient management and surgical decision-making.

A novel three-dimensional volumetric method to measure indirect decompression after percutaneous cement discoplasty.

PURPOSE: Percutaneous cement discoplasty (PCD) is a minimally invasive surgical option to treat patients who suffer from the consequences of advanced disc degeneration. As the current two-dimensional methods can inappropriately measure the difference in the complex 3D anatomy of the spinal segment, our aim was to develop and apply a volumetric method to measure the geometrical change in the surgically treated segments. METHODS: Prospective clinical and radiological data of 10 patients who underwent single- or multilevel PCD was collected. Pre- and postoperative CT scan-based 3D reconstructions were performed. The injected PMMA (Polymethylmethacrylate) induced lifting of the cranial vertebra and the following volumetric change was measured by subtraction of the geometry of the spinal canal from a pre- and postoperatively predefined cylinder. The associations of the PMMA geometry and the volumetric change of the spinal canal with clinical outcome were determined. RESULTS: Change in the spinal canal volume (ΔV) due to the surgery proved to be significant (mean ΔV = 2266.5 ±â€¯1172.2 mm3, n = 16; p = 0.0004). A significant, positive correlation was found between ΔV, the volume and the surface of the injected PMMA. A strong, significant association between pain intensity (low back and leg pain) and the magnitude of the volumetric increase of the spinal canal was shown (ρ = 0.772, p = 0.009 for LBP and ρ = 0.693, p = 0.026 for LP). CONCLUSION: The developed method is accurate, reproducible and applicable for the analysis of any other spinal surgical method. The volume and surface area of the injected PMMA have a predictive power on the extent of the indirect spinal canal decompression. The larger the ΔV the higher clinical benefit was achieved with the PCD procedure. THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE: The developed method has the potential to be integrated into clinical software's to evaluate the efficacy of different surgical procedures based on indirect decompression effect such as PCD, anterior lumbar interbody fusion (ALIF), lateral lumbar interbody fusion (LLIF), oblique lumbar interbody fusion (OLIF), extreme lateral interbody fusion (XLIF). The intraoperative use of the method will allow the surgeon to respond if the decompression does not reach the desired level.