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Paraspinal muscle atrophy is gaining attention in spine surgery due to its link to back pain, spinal degeneration and worse postoperative outcomes. Electrical impedance myography (EIM) is a noninvasive diagnostic tool for muscle quality assessment, primarily utilized for patients with neuromuscular diseases. However, EIM's accuracy for paraspinal muscle assessment remains understudied. In this study, we investigated the correlation between EIM readings and MRI‐derived muscle parameters, as well as the influence of dermal and subcutaneous parameters on these readings. We retrospectively analyzed patients with lumbar spinal degeneration who underwent paraspinal EIM assessment between May 2023 to July 2023. Paraspinal muscle fatty infiltration (FI) and functional cross‐sectional area (fCSA), as well as the subcutaneous thickness were assessed on MRI scans. Skin ultrasound imaging was assessed for dermal thickness and the echogenicities of the dermal and subcutaneous layers. All measurements were performed on the bilaterally. The correlation between EIM readings were compared with ultrasound and MRI parameters using Spearman's correlation analyses. A total of 20 patients (65.0% female) with a median age of 69.5 years (IQR, 61.3–73.8) were analyzed. The fCSA and FI did not significantly correlate with the EIM readings, regardless of frequency. All EIM readings across frequencies correlated with subcutaneous thickness, echogenicity, or dermal thickness. With the current methodology, paraspinal EIM is not a valid alternative to MRI assessment of muscle quality, as it is strongly influenced by the dermal and subcutaneous layers. Further studies are required for refining the methodology and confirming our results. [ABSTRACT FROM AUTHOR]

Purpose: The literature is scarce in exploring the role of imaging parameters like ultrasound (US) as a biomarker for surgical outcomes. The purpose of this study is to investigate the associations between skin US parameters and revision surgery following spine lumbar fusion. Methods: Posterior lumbar fusion patients with 2-years follow-up were assessed. Previous fusion or revision not due to adjacent segment disease (ASD) were excluded. Revisions were classified as cases and non-revision were classified as controls. US measurements conducted at two standardized locations on the lumbar back. Skin echogenicity of the average dermal (AD), upper 1/3 of the dermal (UD), lower 1/3 of the dermal (LD), and subcutaneous layer were measured. Echogenicity was calculated with the embedded echogenicity function of our institution's imaging platform (PACS). Statistical significance was set at p < 0.05. Results: A total of 128 patients (51% female, age 62 [54–72] years) were included in the final analysis. 17 patients required revision surgery. AD, UD, and LD echogenicity showed significantly higher results among revision cases 124.5 [IQR = 115.75,131.63], 128.5 [IQR = 125,131.63] and 125.5 [IQR = 107.91,136.50] compared to the control group 114.3 [IQR = 98.83,124.8], 118.5 [IQR = 109.28,127.50], 114 [IQR = 94.20,126.75] respectively. Conclusion: The findings of this study demonstrate a significant association between higher echogenicity values in different layers of the dermis and requiring revision surgery. The results provide insights into the potential use of skin US parameters as predictors for revision surgery. These findings may reflect underlying alterations in collagen. Further research is warranted to elucidate the mechanisms driving these associations. [ABSTRACT FROM AUTHOR]

Case: A 59-year-old woman presented with progressively worsening neck pain and radicular symptoms. Cervical radiographs revealed C1-C2 dynamic instability. Magnetic resonance imaging and computed tomographic angiogram revealed an anomalous right vertebral artery with intracanal trajectory at C1. A unilateral left C1-C2 fusion with a C1 lateral mass screw and C2 transarticular screw placement was performed due to the anomalous artery. At 14-month follow-up, the patient's cervical symptoms had resolved. Conclusion: In this patient with an aberrant vertebral artery who was indicated for C1-C2 fusion, a unilateral contralateral fusion with a C1 lateral mass screw and C2 transarticular screw was a satisfactory treatment option. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to investigate the impact of sarcopenia and lumbar paraspinal muscle composition (PMC) on patient-reported outcomes (PROs) after lumbar fusion surgery with 12-month follow-up (12 M-FU). Methods: A prospective investigation of patients undergoing elective lumbar fusion was conducted. Preoperative MRI-based evaluation of the cross-sectional area (CSA), the functional CSA (fCSA), and the fat infiltration(FI) of the posterior paraspinal muscles (PPM) and the psoas muscle at level L3 was performed. Sarcopenia was defined by the psoas muscle index (PMI) at L3 (CSAPsoas [cm2]/(patients' height [m])2). PROs included Oswestry Disability Index (ODI), 12-item Short Form Healthy Survey with Physical (PCS-12) and Mental Component Scores (MCS-12) and Numerical Rating Scale back and leg (NRS-L) pain before surgery and 12 months postoperatively. Univariate and multivariable regression determined associations among sarcopenia, PMC and PROs. Results: 135 patients (52.6% female, 62.1 years, BMI 29.1 kg/m2) were analyzed. The univariate analysis demonstrated that a higher FI (PPM) was associated with worse ODI outcomes at 12 M-FU in males. Sarcopenia (PMI) and higher FI (PPM) were associated with worse ODI and MCS-12 at 12 M-FU in females. Sarcopenia and higher FI of the PPM are associated with worse PCS-12 and more leg pain in females. In the multivariable analysis, a higher preoperative FI of the PPM (β = 0.442; p = 0.012) and lower FI of the psoas (β = −0.439; p = 0.029) were associated with a worse ODI at 12 M-FU after adjusting for covariates. Conclusions: Preoperative FI of the psoas and the PPM are associated with worse ODI outcomes one year after lumbar fusion. Sarcopenia is associated with worse ODI, PCS-12 and NRS-L in females, but not males. Considering sex differences, PMI and FI of the PPM might be used to counsel patients on their expectations for health-related quality of life after lumbar fusion. [ABSTRACT FROM AUTHOR]

Objective: Abdominal aortic calcification (AAC), often found incidentally on lateral lumbar radiographs, is increasingly recognized for its association with adverse outcomes in spine surgery. As a marker of advanced atherosclerosis affecting cardiovascular dynamics, this study evaluates AAC's impact on perioperative blood loss in posterior spinal fusion (PSF). Methods: Patients undergoing PSF from March 2016 to July 2023 were included. Estimated blood loss (EBL) and total blood volume (TBV) were calculated. AAC was assessed on lateral lumbar radiographs according to the Kauppila classification. Predictors of the EBL-to-TBV ratio (%EBL/TBV) were examined via univariable and multivariable regression analyses, which adjusted for parameters such as hypertension and aspirin use. Results: A total of 199 patients (47.2% female) were analyzed. AAC was present in 106 patients (53.3%). AAC independently predicted %EBL/TBV, accounting for an increase in blood loss of 4.46% of TBV (95% CI 1.17–7.74, p = 0.008). Conclusions: This is the first study to identify AAC as an independent predictor of perioperative blood loss in PSF. In addition to its link to degenerative spinal conditions and adverse postoperative outcomes, the relationship between AAC and increased blood loss warrants attention in patients undergoing PSF. [ABSTRACT FROM AUTHOR]

Study design: Retrospective review of multicentric data. Objectives: The modified 5-item frailty index is a relatively new tool to assess the post-operative complication risks. It has been recently shown a good predictive value after posterior lumbar fusion. We aimed to compare the predictive value of the modified 5-item frailty index in cervical, thoracic and lumbar surgery. Methods: The American College of Surgeons - National Surgical Quality Improvement Program (ACS-NSQIP) Database 2015-2020 was used to identify patients who underwent elective posterior cervical, thoracic, or lumbar fusion surgeries for degenerative conditions. The mFI-5 score was calculated based on the presence of 5 co-morbidities: congestive heart failure within 30 days prior to surgery, insulin-dependent or noninsulin-dependent diabetes mellitus, chronic obstructive pulmonary disease or pneumonia, partially dependent or totally dependent functional health status at time of surgery, and hypertension requiring medication. Multivariate analysis was used to assess the independent impact of increasing mFI-5 score on the postoperative morbidity while controlling for baseline clinical characteristics. Results: 53 252 patients were included with the mean age of 64.2 ± 7.2. 7946 suffered medical complications (14.9%), 1565 had surgical complications (2.9%), and 3385 were readmitted (6.3%), 363 died (.68%) within 30 days postoperative (6.3%). The mFI-5 items score was significantly associated with higher rates of complications, readmission, and mortality in cervical, thoracic, and lumbar posterior fusion surgery. Conclusion: The modified 5-item frailty score is a reliable tool to predict complications, readmission, and mortality in patients planned for elective posterior spinal fusion surgery. [ABSTRACT FROM AUTHOR]

Purpose: Intervertebral vacuum phenomenon (IVP) and paraspinal muscular atrophy are age-related changes in the lumbar spine. The relationship between both parameters has not been investigated. We aimed to analyze the correlation between IVP and paraspinal muscular atrophy in addition to describing the lumbar vacuum severity (LVS) scale, a new parameter to estimate lumbar degeneration. Methods: We analyzed patients undergoing spine surgery between 2014 and 2016. IVP severity was assessed utilizing CT scans. The combination of vacuum severity on each lumbar level was used to define the LVS scale, which was classified into mild, moderate and severe. MRIs were used to evaluate paraspinal muscular fatty infiltration of the multifidus and erector spinae. The association of fatty infiltration with the severity of IVP at each lumbar level was assessed with a univariable and multivariable ordinal regression model. Results: Two hundred and sixty-seven patients were included in our study (128 females and 139 males) with a mean age of 62.6 years (55.1—71.2). Multivariate analysis adjusted for age, BMI and sex showed positive correlations between LVS-scale severity and fatty infiltration in the multifidus and erector spinae, whereas no correlation was observed in the psoas muscle. Conclusion: IVP severity is positively correlated with paraspinal muscular fatty infiltration. This correlation was stronger for the multifidus than the erector spinae. No correlations were observed in the psoas muscle. The lumbar vacuum severity scale was significantly correlated with advanced disc degeneration with vacuum phenomenon. [ABSTRACT FROM AUTHOR]

Background: Chronic low back pain secondary to degenerative changes in the spine is a common cause of disability, and disc degeneration is one of the most frequent imaging findings. Intervertebral vacuum phenomenon (IVP) is usually observed in advanced degeneration. Recently, this phenomenon has gained interest due to a relatively new surgical technique called percutaneous discoplasty, aimed at treating low back pain secondary to degenerative disc disease in elderly patients. Purpose: To analyze the prevalence and related factors of the vacuum phenomenon in adult patients. Material and Methods: A retrospective cohort study was performed of patients who underwent abdominal computed tomography (CT) for non-spine-related reasons. Age, body mass index, smoking, and CT-based characteristics as presence of IVP, subchondral sclerosis, and facet joint degeneration at the lumbar spine from L1 to the sacrum were included in order to determine the prevalence of the vacuum phenomenon in this population and establish a relationship between this condition and patient demographics and other signs of spine degeneration, such as sclerosis and facet joint disease. Results: A total of 238 patients were included in the study (114 men, 124 women; mean age = 75.6 ± 12.3 years. In total, 91 (38%) patients had at least one level of IVP; 59 (25%) patients exhibited subchondral sclerosis, and 235 (98%) facet joint degeneration. Among risk factors, age, smoking, and subchondral sclerosis were significantly associated with the presence of vacuum. Conclusion: IVP was present in 38% of participants. Risk factors associated with vacuum were age, smoking, and subchondral sclerosis. [ABSTRACT FROM AUTHOR]

Background: Modic changes and intervertebral vacuum phenomenon (IVP) are considered spinal degenerative changes. The correlation between Modic and IVP has not been analyzed in the literature. Purpose: To analyze the correlation between IVP severity, Modic changes, and subchondral sclerosis across the lumbar spine in patients with lumbar degeneration. Material and Methods: This is a retrospective study analyzing patients who underwent percutaneous cement discoplasty at a single institution between 2015 and 2020. Preoperative magnetic resonance imaging and computed tomography scans were analyzed to make the measurements. Modic type and grade as well as severity of IVP were preoperatively measured. The association between Modic type, grade, subchondral sclerosis, and the presence of IVP was analyzed. Results: In total, 110 patients (mean age = 77.03 ± 7.1 years) were finally included in the study. Per level correlation analysis showed a significant positive association between IVP and Modic type, IVP and Modic grade, and IVP and subchondral sclerosis. Moreover, subchondral sclerosis was significantly associated with Modic type and grade. Conclusion: Our study showed a significant positive correlation among Modic changes, IVP, and subchondral sclerosis throughout the lumbar spine. Our findings support the theory that endplate degeneration parameters are associated with the presence and severity of IVP. [ABSTRACT FROM AUTHOR]

Background: Abdominal aortic calcification (AAC) is associated with lower back pain, reduced bone mineral density of the spine. Vascular changes could also affect the already sparsely perfused intervertebral endplate and intervertebral disc. Methods: Lumbar MRIs and lateral radiographs of patients with lower back pain were retrospectively analyzed. AAC was assessed on lateral lumbar radiographs according to the Kauppila score, with a maximum score of 24. Patients were grouped into no (AAC = 0), moderate (AAC 1 to ≤ 4), and severe AAC (AAC ≥ 5). Endplate and disc degeneration were classified according to the total endplate score (TEPS) and Pfirrmann classification. The associations between AAC and degenerative changes was analyzed with a generalized mixed model and was adjusted for age, sex, body mass index as well as diabetes mellitus, and smoking status. Results: A total of 217 patients (47.9% female) were included in the analysis, totaling 1085 intervertebral levels. Of those, 45 (20.7%) patients had moderate, and 39 (18%) had severe AAC. The results of the generalized mixed model showed no significant association between AAC and disc degeneration (p > 0.05). In contrast, a significant positive association between AAC and the severity of TEPS (β: 0.51, 95% CI: 1.92—2.12, p = 0.004) was observed in the multivariable analysis. Conclusions: This study demonstrates an independent association between AAC and endplate degeneration. These findings expand our knowledge about the degenerative cascade of the lumbar spine and suggest that AAC might be a modifiable risk factor for endplate changes. [ABSTRACT FROM AUTHOR]

Background: Aortic abdominal calcification (AAC) is associated with spine-related conditions, such as lower back pain and reduced bone mineral density. Similar to peripheral vascular disease, AAC possibly reduces blood flow to the lumbar posterior paraspinal muscles (PPM) which may lead to atrophy and increased fatty infiltration. Methods: Imaging of patients with lower back pain was analyzed. AAC was assessed on lateral lumbar radiographs according to the Kauppila classification. The cross-sectional area of the PPM was measured on a T2-weighted axial MRI sequence and the functional cross-sectional area (fCSA) and fatty infiltration (FI) were calculated with custom software. The association of AAC and FI as well as AAC and fCSA was assessed by multivariable linear regression, adjusted for age, sex, body mass index (BMI), diabetes, and smoking. Results: Two hundred and thirty patients (47.8% female) with a median age of 60 years (IQR 48–68) were analyzed. In patients, without AAC the median FI of the PPM was 33.3% (IQR 29.1–37.6%), compared to 44.6% (IQR 38.5–54.3%) in patients with AAC (p < 0.001). In the multivariable linear regression, both fCSA and FI of the PPM were significantly and independently associated with the degree of AAC (p = 0.037 and p = 0.015, respectively). Conclusions: This is the first study to demonstrate a significant and independent association between AAC and PPM morphology. The results of this study improve our understanding of the interaction between AAC and spinal musculature, with AAC being a reason for atrophy of the PPM. [ABSTRACT FROM AUTHOR]

Study design: Systematic Review and Meta-analysis. Objective: Surgical alternatives to treat lumbar spinal stenosis and instability include indirect (ALIF, OLIF, and LLIF) and direct (TLIF or posterior lumbar interbody fusion) decompression and fusion interventions. Although both approaches have proven to be effective in reducing symptoms, it is unknown if there is any difference in effectiveness between them. In this systematic review and meta-analysis, we aimed to evaluate postoperative pain and disability in patients treated whit indirect vs direct decompression and fusion approaches. Methods: We conducted a systematic review of the literature consulting several databases and identified studies that enrolled patients diagnosed with degenerative lumbar spinal stenosis and instability treated with indirect or direct decompression and fusion techniques. Our primary endpoints were the visual analogue scale, Oswestry Disability Index, and the Japanese Orthopedics Association Back Pain Evaluation Questionnaire 1 year after the procedure. Secondary outcomes included complication rate, blood loss, and surgical time. Results: Nine retrospective and comparative studies were included enrolling a total of 1004 participants. Both surgical strategies had satisfactory clinical outcomes with no significant difference at 1 year. Although the complication rate was similar for both groups, the profile of the adverse events was different. In addition, patients treated with indirect decompression and fusion had significantly less blood loss and operative times. Conclusions: Indirect and direct decompression and fusion techniques are similarly effective in treating patients with lumbar spinal stenosis and instability. The ID group had significantly lower intraoperative blood loss and surgical time values. [ABSTRACT FROM AUTHOR]

Study Design: Multicentric retrospective study, Level of evidence III. Objective: The objective of this multicentric study was to analyze the prevalence and risk factors of early postoperative complications in adult spinal deformity patients treated with fusion. Additionally, we studied the impact of complications on unplanned readmission and hospital length of stay. Methods: Eight spine centers from 6 countries in Latin America were involved in this study. Patients with adult spinal deformity treated with fusion surgery from 2017 to 2019 were included. Baseline and surgical characteristics such as age, sex, comorbidities, smoking, number of levels fused, number of surgical approaches were analyzed. Postoperative complications at 30 days were recorded according to Clavien-Dindo and Glassman classifications. Results: 172 patients (120 females/52 males, mean age 59.4 ± 17.6) were included in our study. 78 patients suffered complications (45%) at 30 days, 43% of these complications were considered major. Unplanned readmission was observed in 35 patients (20,3%). Risk factors for complications were: Smoking, previous comorbidities, number of levels fused, two or more surgical approaches and excessive bleeding. Hospital length of stay in patients without and with complications was of 7.8 ± 13.7 and 17 ± 31.1 days, respectively (P 0.0001). Conclusion: The prevalence of early postoperative complications in adult spinal deformity patients treated with fusion was of 45% in our study with 20% of unplanned readmissions at 30 days. Presence of complications significantly increased hospital length of stay. [ABSTRACT FROM AUTHOR]

Meissner-Haecker et al. [[7]] compared spine and pelvic trauma surgeons and found that the interobserver agreement, considering fracture severity types, was substantial for spine surgeons ( I i = 0.68) and pelvic trauma surgeons ( I i = 0.74). Additionally, several traumatic Type B fractures (especially Type B3 fractures) are more severe than Type C0 insufficiency fractures; perhaps this classification should be restricted only to traumatic injuries, such as other AOSpine classification systems. In addition, it is unclear whether a unilateral alar fracture and a transverse fracture correspond to a Type B or Type C injury; although this is an unusual injury pattern, these fractures may be challenging to classify. Roy-Camille et al. [[11]] published a morphologic classification for transverse sacral fractures in 1985; they theorized that the fracture pattern was determined by flexion or extension of the lumbar spine at the time of injury. [Extracted from the article]

Background: Recently, a scoring system to grade sacroiliac joint (SIJ) degeneration using computed tomography (CT) scans was described. No independent evaluation has determined the inter- and intra-observer agreement using this scheme. Purpose: To perform an independent inter- and intra-observer agreement assessment using the Eno classification and determining gas in the SIJ. Material and Methods: We studied 64 patients aged ≥60 years who were evaluated with abdominal and pelvic computed tomography scans. Six physicians (three orthopaedic spine surgeons and three musculoskeletal radiologists) assessed axial images to grade SIJ degeneration into grade 0 (normal), grade 1 (mild degeneration), grade 2 (significant degeneration), and grade 3 (ankylosis). We also evaluated the agreement assessing the presence of gas in the SIJ. After a four-week interval, all cases were presented in a random sequence for repeat assessment. We determined the agreement using the kappa (κ) or weighted kappa coefficient (wκ). Results: The inter-observer agreement was moderate (wκ = 0.50 [0.44–0.56]), without differences among surgeons (wκ = 0.53 [0.45–0.61]) and radiologists (wκ = 0.49 [0.42–0.57]). The agreement evaluating the presence of gas was also moderate (κ = 0.45 [0.35–0.54]), but radiologists obtained better agreement (κ = 0.61 [0.48–0.72]) than surgeons (κ = 0.29 [0.18–0.39]). The intra-observer agreement using the classification was substantial (wκ = 0.79 [0.76–0.82]), without differences comparing surgeons (wκ = 0.75 [0.70–0.80]) and radiologists (wκ = 0.83 [0.79–0.87]). The intra-rater agreement evaluating gas was substantial (κ = 0.77 [0.72–0.82]), without differences between surgeons (κ = 0.71 [0.63–0.78]) and radiologists (κ = 0.84 [0.78–0.90]). Conclusion: Given the only moderate agreement obtained using the Eno classification, it does not seem adequate to be used in clinical practice or in research. [ABSTRACT FROM AUTHOR]

Background: We analyzed the role of hypoalbuminemia, dialysis, and other risk factors that increase morbidity/mortality following surgery for primary pyogenic spinal infections (PSIs). The American College of Surgeons' National Surgical Quality Improvement Program (ACS-NSQIP) that included 627 patients was utilized as our database. Methods: Primary spinal surgery for spondylodiscitis was evaluated in a ACS-NSQIP database involving 627 patients between 2010 and 2019. Outcome assessment included evaluation of 30-day postoperative morbidity, and mortality rates. Results: Within 30 postoperative days, complications occurred in 14.6% (92/627) of patients; 59 (9.4%) required readmission, and 39 (6.2%) required additional surgery. The most common complications were: wound infections, pneumonia, septic shock, and death (1.8%). Hypoalbuminemia (i.e., significantly associated with unplanned readmission and reoperation), and dialysis were the two major risk factors contributing to increased perioperative morbidity and mortality. Conclusion: Among 627 ACS-NSQIP patients undergoing primary surgery for PSIs, hypoalbuminemia and dialysis were associated with higher risks of major perioperative morbidity (i.e., within 30 postoperative days - mostly readmissions and reoperations) and mortality. [ABSTRACT FROM AUTHOR]

Purpose: Pola et al. described a clinical-radiological classification of pyogenic spinal infections (PSI) based on magnetic resonance imaging (MRI) features including vertebral destruction, soft tissue involvement, and epidural abscess, along with the neurological status. We performed an inter- and intra-observer agreement evaluation of this classification. Methods: Complete MRI studies of 80 patients with PSI were selected and classified using the scheme described by Pola et al. by seven evaluators. After a four-week interval, all cases were presented to the same assessors in a random sequence for repeat assessment. We used the weighted kappa statistics (wκ) to establish the inter- and intra-observer agreement. Results: The inter-observer agreement was substantial considering the main categories (wκ = 0.77; 0.71–0.82), but moderate considering the subtypes (wκ = 0.51; 0.45–0.58). The intra-observer agreement was substantial considering the main types (wκ = 0.65; 0.59–0.71), and moderate considering the subtypes (wκ = 0.58; 0.54–0.63). Conclusion: The agreement at the main type level indicates that this classification allows adequate communication and may be used in clinical practice; at the subtypes level, the agreement is only moderate. [ABSTRACT FROM AUTHOR]

Background: Preoperative optimization in patients undergoing posterior spinal fusion is essential to limit the number and severity of postoperative complications. Here, we, additionally, evaluated the impact of hypoalbuminemia on morbidity and mortality after posterior spinal fusion surgery. Methods: This retrospective analysis was performed using data from a prospective multicentric database (ACSNSQIP: 2015-2020) regarding patients undergoing posterior spinal fusions. Factors studied included; baseline demographics and 30-day postoperative complications (i.e., reoperations, readmissions, and mortality rates). Results: There were 6805 patients who met the inclusion criteria. They averaged 62 years of age and had an average BMI of 30.2. Within the 30-day postoperative period, 634 (9.3%) sustained complications; 467 (6.9%) were readmitted, 263 (3.9%) required reoperations, and 37 (0.5%) expired. Although multiple preoperative risk factors were analyzed, hypoalbuminemia, severe hypoalbuminemia, and dialysis were the strongest independent risk factors associated with complications (i.e., reoperations, readmissions, and mortality). Conclusion: Hypoalbuminemia, severe hypoalbuminemia, and dialysis were significant predictors for morbidity and mortality after posterior spinal fusion surgery. [ABSTRACT FROM AUTHOR]

Background: We analyzed the role of hypoalbuminemia, dialysis, and other risk factors that increase morbidity/mortality following surgery for primary pyogenic spinal infections (PSIs). The American College of Surgeons' National Surgical Quality Improvement Program (ACS-NSQIP) that included 627 patients was utilized as our database. Methods: Primary spinal surgery for spondylodiscitis was evaluated in a ACS-NSQIP database involving 627 patients between 2010 and 2019. Outcome assessment included evaluation of 30-day postoperative morbidity, and mortality rates. Results: Within 30 postoperative days, complications occurred in 14.6% (92/627) of patients; 59 (9.4%) required readmission, and 39 (6.2%) required additional surgery. The most common complications were: wound infections, pneumonia, septic shock, and death (1.8%). Hypoalbuminemia (i.e., significantly associated with unplanned readmission and reoperation), and dialysis were the two major risk factors contributing to increased perioperative morbidity and mortality. Conclusion: Among 627 ACS-NSQIP patients undergoing primary surgery for PSIs, hypoalbuminemia and dialysis were associated with higher risks of major perioperative morbidity (i.e., within 30 postoperative days - mostly readmissions and reoperations) and mortality. [ABSTRACT FROM AUTHOR]

Purpose: The authors describe a percutaneous technique to treat advanced degenerative disk disease in elderly patients. Method: A step-by-step technical description based on our experience in selected cases. Result: Postoperative imaging results are presented as well as indications and recommendations. Conclusion: Percutaneous discoplasty can result as an alternative minimal invasive strategy for the treatment of advanced degenerative disk disease. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective analysis of prospectively collected data. Objectives: Our goal was to assess radiographic characteristics associated with agreement and disagreement in treatment recommendation in thoracolumbar (TL) burst fractures. Methods: A panel of 22 AO Spine Knowledge Forum Trauma experts reviewed 183 cases and were asked to: (1) classify the fracture; (2) assess degree of certainty of PLC disruption; (3) assess degree of comminution; and (4) make a treatment recommendation. Equipoise threshold used was 77% (77:23 distribution of uncertainty or 17 vs 5 experts). Two groups were created: consensus vs equipoise. Results: Of the 183 cases reviewed, the experts reached full consensus in only 8 cases (4.4%). Eighty-one cases (44.3%) were included in the agreement group and 102 cases (55.7%) in the equipoise group. A3/A4 fractures were more common in the equipoise group (92.0% vs 83.7%, P <.001). The agreement group had higher degree of certainty of PLC disruption [35.8% (SD 34.2) vs 27.6 (SD 27.3), P <.001] and more common use of the M1 modifier (44.3% vs 38.3%, P <.001). Overall, the degree of comminution was slightly higher in the equipoise group [47.8 (SD 20.5) vs 45.7 (SD 23.4), P <.001]. Conclusions: The agreement group had a higher degree of certainty of PLC injury and more common use of M1 modifier (more type B fractures). The equipoise group had more A3/A4 type fractures. Future studies are required to identify the role of comminution in decision making as degree of comminution was slightly higher in the equipoise group. [ABSTRACT FROM AUTHOR]

Study Design: This paper presents a description of a conceptual framework and methodology that is applicable to the manuscripts that comprise this focus issue. Objectives: Our goal is to present a conceptual framework which is relied upon to better understand the processes through which surgeons make therapeutic decisions around how to treat thoracolumbar burst fractures (TL) fractures. Methods: We will describe the methodology used in the AO Spine TL A3/4 Study prospective observational study and how the radiographs collected for this study were utilized to study the relationships between various variables that factor into surgeon decision making. Results: With 22 expert spine trauma surgeons analyzing the acute CT scans of 183 patients with TL fractures we were able to perform pairwise analyses, look at reliability and correlations between responses and develop frequency tables, and regression models to assess the relationships and interactions between variables. We also used machine learning to develop decision trees. Conclusions: This paper outlines the overall methodological elements that are common to the subsequent papers in this focus issue. [ABSTRACT FROM AUTHOR]

Study design: Predictive algorithm via decision tree Objectives: Artificial intelligence (AI) remain an emerging field and have not previously been used to guide therapeutic decision making in thoracolumbar burst fractures. Building such models may reduce the variability in treatment recommendations. The goal of this study was to build a mathematical prediction rule based upon radiographic variables to guide treatment decisions. Methods: Twenty-two surgeons from the AO Knowledge Forum Trauma reviewed 183 cases from the Spine TL A3/A4 prospective study (classification, degree of certainty of posterior ligamentous complex (PLC) injury, use of M1 modifier, degree of comminution, treatment recommendation). Reviewers' regions were classified as Europe, North/South America and Asia. Classification and regression trees were used to create models that would predict the treatment recommendation based upon radiographic variables. We applied the decision tree model which accounts for the possibility of non-normal distributions of data. Cross-validation technique as used to validate the multivariable analyses. Results: The accuracy of the model was excellent at 82.4%. Variables included in the algorithm were certainty of PLC injury (%), degree of comminution (%), the use of M1 modifier and geographical regions. The algorithm showed that if a patient has a certainty of PLC injury over 57.5%, then there is a 97.0% chance of receiving surgery. If certainty of PLC injury was low and comminution was above 37.5%, a patient had 74.2% chance of receiving surgery in Europe and Asia vs 22.7% chance in North/South America. Throughout the algorithm, the use of the M1 modifier increased the probability of receiving surgery by 21.4% on average. Conclusion: This study presents a predictive analytic algorithm to guide decision-making in the treatment of thoracolumbar burst fractures without neurological deficits. PLC injury assessment over 57.5% was highly predictive of receiving surgery (97.0%). A high degree of comminution resulted in a higher chance of receiving surgery in Europe or Asia vs North/South America. Future studies could include clinical and other variables to enhance predictive ability or use machine learning for outcomes prediction in thoracolumbar burst fractures. [ABSTRACT FROM AUTHOR]

Study Design: A prospective study. Objective: to evaluate the impact of vertebral body comminution and Posterior Ligamentous Complex (PLC) integrity on the treatment recommendations of thoracolumbar fractures among an expert panel of 22 spine surgeons. Methods: A review of 183 prospectively collected thoracolumbar burst fracture computed tomography (CT) scans by an expert panel of 22 trauma spine surgeons to assess vertebral body comminution and PLC integrity. This study is a sub-study of a prospective observational study of thoracolumbar burst fractures (Spine TL A3/A4). Each expert was asked to grade the degree of comminution and certainty about the PLC disruption from 0 to 100, with 0 representing the intact vertebral body or intact PLC and 100 representing complete comminution or complete PLC disruption, respectively. Results: ≥45% comminution had a 74% chance of having surgery recommended, while <25% comminution had an 86.3% chance of non-surgical treatment. A comminution from 25 to 45% had a 57% chance of non-surgical management. ≥55% PLC injury certainity had a 97% chance of having surgery, and ≥45-55% PLC injury certainty had a 65%. <20% PLC injury had a 64% chance of having non-operative treatment. A 20 to 45% PLC injury certainity had a 56% chance of non-surgical management. There was fair inter-rater agreement on the degree of comminution (ICC.57 [95% CI 0.52-.63]) and the PLC integrity (ICC.42 [95% CI 0.37-.48]). Conclusion: The study concludes that vetebral comminution and PLC integrity are major dterminant in decision making of thoracolumbar fractures without neurological deficit. However, more objective, reliable, and accurate methods of assessment of these variables are warranted. [ABSTRACT FROM AUTHOR]

Study Design: Reliability study utilizing 183 injury CT scans by 22 spine trauma experts with assessment of radiographic features, classification of injuries and treatment recommendations. Objectives: To assess the reliability of the AOSpine TL Injury Classification System (TLICS) including the categories within the classification and the M1 modifier. Methods: Kappa and Intraclass correlation coefficients were produced. Associations of various imaging characteristics (comminution, PLC status) and treatment recommendations were analyzed through regression analysis. Multivariable logistic regression modeling was used for making predictive algorithms. Results: Reliability of the AO Spine TLICS at differentiating A3 and A4 injuries (N = 71) (K =.466; 95% CI.458 –.474; P <.001) demonstrated moderate agreement. Similarly, the average intraclass correlation coefficient (ICC) amongst A3 and A4 injuries was excellent (ICC =.934; 95% CI.919 –.947; P <.001) and the ICC between individual measures was moderate (ICC =.403; 95% CI.351 –.461; P <.001). The overall agreement on the utilization of the M1 modifier amongst A3 and A4 injuries was fair (K =.161; 95% CI.151 –.171; P <.001). The ICC for PLC status in A3 and A4 injuries averaged across all measures was excellent (ICC =.936; 95% CI.922 –.949; P <.001). The M1 modifier suggests respondents are nearly 40% more confident that the PLC is injured amongst all injuries. The M1 modifier was employed at a higher frequency as injuries were classified higher in the classification system. Conclusions: The reliability of surgeons differentiating between A3 and A4 injuries in the AOSpine TLICS is substantial and the utilization of the M1 modifier occurs more frequently with higher grades in the system. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective analysis of prospectively collected data. Objectives: To compare decision-making between an expert panel and real-world spine surgeons in thoracolumbar burst fractures (TLBFs) without neurological deficits and analyze which factors influence surgical decision-making. Methods: This study is a sub-analysis of a prospective observational study in TL fractures. Twenty two experts were asked to review 183 CT scans and recommend treatment for each fracture. The expert recommendation was based on radiographic review. Results: Overall agreement between the expert panel and real-world surgeons regarding surgery was 63.2%. In 36.8% of cases, the expert panel recommended surgery that was not performed in real-world scenarios. Conversely, in cases where the expert panel recommended non-surgical treatment, only 38.6% received non-surgical treatment, while 61.4% underwent surgery. A separate analysis of A3 and A4 fractures revealed that expert panel recommended surgery for 30% of A3 injuries and 68% of A4 injuries. However, 61% of patients with both A3 and A4 fractures received surgery in the real world. Multivariate analysis demonstrated that a 1% increase in certainty of PLC injury led to a 4% increase in surgery recommendation among the expert panel, while a.2% increase in the likelihood of receiving surgery in the real world. Conclusion: Surgical decision-making varied between the expert panel and real-world treating surgeons. Differences appear to be less evident in A3/A4 burst fractures making this specific group of fractures a real challenge independent of the level of expertise. [ABSTRACT FROM AUTHOR]

Study Design: Prospective Observational Study. Objective: To determine the alignment of the AO Spine Thoracolumbar Injury Classification system and treatment algorithm with contemporary surgical decision making. Methods: 183 cases of thoracolumbar burst fractures were reviewed by 22 AO Spine Knowledge Forum Trauma experts. These experienced clinicians classified the fracture morphology, integrity of the posterior ligamentous complex and degree of comminution. Management recommendations were collected. Results: There was a statistically significant stepwise increase in rates of operative management with escalating category of injury (P <.001). An excellent correlation existed between recommended expert management and the actual treatment of each injury category: A0/A1/A2 (OR 1.09, 95% CI 0.70-1.69, P =.71), A3/4 (OR 1.62, 95% CI 0.98-2.66, P =.58) and B1/B2/C (1.00, 95% CI 0.87-1.14, P =.99). Thoracolumbar A4 fractures were more likely to be surgically stabilized than A3 fractures (68.2% vs 30.9%, P <.001). A modifier indicating indeterminate ligamentous injury increased the rate of operative management when comparing type B and C injuries to type A3/A4 injuries (OR 39.19, 95% CI 20.84-73.69, P <.01 vs OR 27.72, 95% CI 14.68-52.33, P <.01). Conclusions: The AO Spine Thoracolumbar Injury Classification system introduces fracture morphology in a rational and hierarchical manner of escalating severity. Thoracolumbar A4 complete burst fractures were more likely to be operatively managed than A3 fractures. Flexion-distraction type B injuries and translational type C injuries were much more likely to have surgery recommended than type A fractures regardless of the M1 modifier. A suspected posterior ligamentous injury increased the likelihood of surgeons favoring surgical stabilization. [ABSTRACT FROM AUTHOR]

Background: Intraoperative neurophysiological monitoring (IOM) has become valuable in spine surgery. Unfortunately, it is not always available in many spine centers, especially in developing countries. Our aim was to evaluate the accessibility and barriers to IOM in spine surgery in Latin America. Methods: We designed a questionnaire to evaluate the characteristics of surgeons and their opinions on the usefulness of IOM for different spine operations. The survey was sent to 9616 members and registered users of AO Spine Latin America (AOSLA) from August 1, 2019, to August 21, 2019. Major variables studied included nationality, years of experience, specialty (orthopedics or neurosurgery), level of complexity of the hospital, number of spine surgeries performed per year by the spine surgeon, the types of spinal pathologies commonly managed, and how important IOM was to the individual surgeon. General questions to evaluate use included accessibility, limitations of IOM usage, management of IOM changes, and the legal value of IOM. The results were analyzed and compared between neurosurgeon and orthopedics, level of surgeon experience, and country of origin. Results: Questionnaires were answered by 200 members of AOSLA from 16 different countries. The most common responses were obtained from orthopedic surgeons (62%), those with more than 10 years of practice (54%); majority of surgeons performed more than 50 spine surgeries per year (69%) and treated mainly spine degenerative diseases (76%). Most surgeons think that IOM has a real importance during surgeries (92%) and not just a legal value. Although surgeons mostly considered IOM essential to scoliosis surgery in adolescents (70%), thoracolumbar kyphosis correction (68%), and intramedullary tumors (68%), access to IOM was limited to 57% for economic reasons. Of interest, in 64% of cases, where IOM was available and significant change occurred, the actual operative procedures were significantly altered. Conclusion: Despite the fact that 68% of spine surgeons believe IOM to be indispensable for complex spine surgery, cost remains the main barrier to its use/availability in Latin America. [ABSTRACT FROM AUTHOR]

First, the entry point: the authors use a pedicular entry point that inevitably breaks the endplate, while in our experience we prefer to use the extrapedicular entry point targeting the vacuum and using the pedicular entry point when the extrapedicular is difficult in terms of access such as the L5-sacrum level. I personally found this paper interesting, well designed, and I encourage the spine community to get more knowledge regarding this technique for many reasons: minimally invasive, low costs, and low morbidity to the patients. My question to the authors is: If they prefer the pedicular entry point to intentionally break the endplate in order to create some inflammatory reaction that may decrease low back pain?. [Extracted from the article]