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Osteoarthritis (OA) is a joint disease featuring cartilage breakdown and chronic pain. Although age and joint trauma are prominently associated with OA occurrence, the trigger and signaling pathways propagating their pathogenic aspects are ill defined. Following long-term catabolic activity and traumatic cartilage breakdown, debris accumulates and can trigger Toll-like receptors (TLRs). Here we show that TLR2 stimulation suppressed the expression of matrix proteins and induced an inflammatory phenotype in human chondrocytes. Further, TLR2 stimulation impaired chondrocyte mitochondrial function, resulting in severely reduced adenosine triphosphate (ATP) production. RNA-sequencing analysis revealed that TLR2 stimulation upregulated nitric oxide synthase 2 (NOS2) expression and downregulated mitochondria function-associated genes. NOS inhibition partially restored the expression of these genes, and rescued mitochondrial function and ATP production. Correspondingly, Nos2-/- mice were protected from age-related OA development. Taken together, the TLR2-NOS axis promotes human chondrocyte dysfunction and murine OA development, and targeted interventions may provide therapeutic and preventive approaches in OA.
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Cartílago Articular , Osteoartritis , Humanos , Ratones , Animales , Condrocitos/metabolismo , Receptor Toll-Like 2/genética , Receptor Toll-Like 2/metabolismo , Osteoartritis/metabolismo , Receptores Toll-Like/metabolismo , Cartílago Articular/metabolismo , Células CultivadasRESUMEN
PURPOSE: The sole determination of volumetric bone mineral density (vBMD) is insufficient to evaluate overall bone integrity. The accumulation of advanced glycation endproducts (AGEs) stiffens and embrittles collagen fibers. Despite the important role of AGEs in bone aging, the relationship between AGEs and vBMD is poorly understood. We hypothesized that an accumulation of AGEs, a marker of impaired bone quality, is related to decreased vBMD. METHODS: Prospectively collected data of 127 patients undergoing lumbar fusion were analyzed. Quantitative computed tomography (QCT) measurements were performed at the lumbar spine. Intraoperative bone biopsies were obtained and analyzed with confocal fluorescence microscopy for fluorescent AGEs, both trabecular and cortical. Spearman's correlation coefficients were calculated to examine relationships between vBMD and fAGEs, stratified by sex. Multivariable linear regression analysis with adjustments for age, sex, body mass index (BMI), race, diabetes mellitus and HbA1c was used to investigate associations between vBMD and fAGEs. RESULTS: One-hundred and twenty-seven patients (51.2% female, 61.2 years, BMI of 28.7 kg/m2) with 107 bone biopsies were included in the final analysis, excluding patients on anti-osteoporotic drug therapy. In the univariate analysis, cortical fAGEs increased with decreasing vBMD at (r = -0.301; p = 0.030), but only in men. In the multivariable analysis, trabecular fAGEs increased with decreasing vBMD after adjusting for age, sex, BMI, race, diabetes mellitus and HbA1c (ß = 0.99;95%CI=(0.994,1.000); p = 0.04). CONCLUSION: QCT-derived vBMD measurements were found to be inversely associated with trabecular fAGEs. Our results enhance the understanding of bone integrity by suggesting that spine surgery patients with decreased bone quantity may also have poorer bone quality.
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Densidad Ósea , Vértebras Lumbares , Masculino , Humanos , Femenino , Hemoglobina Glucada , Vértebras Lumbares/diagnóstico por imagen , Vértebras Lumbares/cirugía , Tomografía Computarizada por Rayos X/métodos , EnvejecimientoRESUMEN
PURPOSE: Anterior (ALIF) and lateral (LLIF) lumbar interbody fusion is associated with significant postoperative pain, opioid consumption and length of stay. Transversus abdominis plane (TAP) blocks improve these outcomes in other surgical subtypes but have not been applied to spine surgery. A retrospective study of 250 patients was performed to describe associations between TAP block and outcomes after ALIF/LLIF. METHODS: The electronic medical records of 129 patients who underwent ALIF or LLIF with TAP block were compared to 121 patients who did not. All patients were cared for under a standardized perioperative care pathway with comprehensive multimodal analgesia. Differences in patent demographics, surgical factors, length of stay (LOS), opioid consumption, opioid-related side effects and pain scores were compared in bivariable and multivariable regression analyses. RESULTS: In bivariable analyses, TAP block was associated with a significantly shorter LOS, less postoperative nausea/vomiting and lower opioid consumption in the post-anesthesia care unit (PACU). In multivariable analyses, TAP block was associated with significantly shorter LOS (ß - 12 h, 95% CI (- 22, - 2 h); p = 0.021). Preoperative opioid use was a strong predictive factor for higher opioid consumption in the PACU, opioid use in the first 24 h after surgery and longer LOS. We did not find significant differences in pain scores at any times between the groups. CONCLUSION: TAP block may represent an effective addition to pain management and opioid-reducing strategies and improve outcomes after ALIF/LLIF. Prospective trials are warranted to further explore these associations.
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Músculos Abdominales , Analgésicos Opioides , Humanos , Tiempo de Internación , Dolor Postoperatorio/tratamiento farmacológico , Estudios Prospectivos , Estudios RetrospectivosRESUMEN
PURPOSE: High body mass index (BMI) is positively correlated with bone mineral density (BMD) in healthy adults; however, the effect of BMI on regional segmental BMDs in the axial skeleton is unclear. In addition, obese patients often have glucose intolerance and patients with lumbar spine pathology commonly have a history of epidural steroid injections (ESIs). The purpose of this study is to evaluate the effect of these patient factors on regional differences in BMD measured by quantitative computed tomography (QCT) in a lumbar fusion patient cohort. METHODS: The data were obtained from a database comprised of clinical and preoperative CT data from 296 patients who underwent primary posterior lumbar spinal fusion from 2014 to 2017. QCT-vBMDs of L1 to L5, S1 body, and sacral alae were measured. Multivariate linear regression analyses were performed with setting vBMDs as the response variables. As explanatory variables, age, sex, race, current smoking, categorized BMI, diabetes, and ESI were chosen a priori. RESULTS: A total of 260 patients were included in the final analysis. Multivariate analyses demonstrated that obese and morbidly obese patients had significantly higher vBMD in the sacral alae (SA). Diabetes showed independent positive associations with vBMDs in L1, L2, and the SA. Additionally, patients with an ESI history demonstrated significantly lower vBMD in the SA. CONCLUSIONS: Our results demonstrate that obesity, diabetes, and epidural steroids affected vBMD differently by lumbosacral spine region. The vBMD of the SA appeared to be more sensitive to various patient factors than other lumbar regions.
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Diabetes Mellitus , Obesidad Mórbida , Adulto , Densidad Ósea , Humanos , Vértebras Lumbares/diagnóstico por imagen , Esteroides/efectos adversos , Tomografía Computarizada por Rayos XRESUMEN
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.
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Densidad Ósea , Fusión Vertebral , Humanos , Vértebras Lumbares/diagnóstico por imagen , Vértebras Lumbares/cirugía , Región Lumbosacra , Estudios RetrospectivosRESUMEN
OBJECTIVE: Osteoporosis is a metabolic bone disease that increases the risk for fragility fractures. Screening and diagnosis can be achieved by measuring bone mineral density (BMD) using quantitative CT tomography (QCT) in the lumbar spine. QCT-derived BMD measurements can be used to diagnose osteopenia or osteoporosis based on American College of Radiology (ACR) thresholds. Many reports exist regarding the disease prevalence in asymptomatic and disease-specific populations; however, osteoporosis/osteopenia prevalence rates in lumbar spine fusion patients without fracture have not been reported. The purpose of this study was to define osteoporosis and osteopenia prevalence in lumbar fusion patients using QCT. METHODS: A retrospective review of prospective data was performed. All patients undergoing lumbar fusion surgery who had preoperative fine-cut CT scans were eligible. QCT-derived BMD measurements were performed at L1 and L2. The L1-2 average BMD was used to classify patients as having normal findings, osteopenia, or osteoporosis based on ACR criteria. Disease prevalence was calculated. Subgroup analyses based on age, sex, ethnicity, and history of abnormal BMD were performed. Differences between categorical groups were calculated with Fisher's exact test. RESULTS: Overall, 296 consecutive patients (55.4% female) were studied. The mean age was 63 years (range 21-89 years). There were 248 (83.8%) patients with ages ≥ 50 years. No previous clinical history of abnormal BMD was seen in 212 (71.6%) patients. Osteopenia was present in 129 (43.6%) patients and osteoporosis in 44 (14.9%). There were no prevalence differences between sex or race. Patients ≥ 50 years of age had a significantly higher frequency of osteopenia/osteoporosis than those who were < 50 years of age. CONCLUSIONS: In 296 consecutive patients undergoing lumbar fusion surgery, the prevalence of osteoporosis was 14.9% and that for osteopenia was 43.6% diagnosed by QCT. This is the first report of osteoporosis disease prevalence in lumbar fusion patients without vertebral fragility fractures diagnosed by QCT.
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Enfermedades Óseas Metabólicas/diagnóstico por imagen , Enfermedades Óseas Metabólicas/epidemiología , Osteoporosis/diagnóstico por imagen , Osteoporosis/epidemiología , Fusión Vertebral/métodos , Tomografía Computarizada por Rayos X/métodos , Adulto , Anciano , Anciano de 80 o más Años , Densidad Ósea/fisiología , Enfermedades Óseas Metabólicas/cirugía , Estudios de Cohortes , Femenino , Humanos , Vértebras Lumbares/diagnóstico por imagen , Vértebras Lumbares/cirugía , Masculino , Persona de Mediana Edad , Osteoporosis/cirugía , Prevalencia , Estudios Prospectivos , Estudios Retrospectivos , Adulto JovenRESUMEN
Introduction: Mechanical loading is known to determine the course of bone fracture healing. We hypothesise that lower limb long bone loading differs with knee flexion angle during walking and frontal knee alignment, which affects fracture healing success. Materials and methods: Using our musculoskeletal in silico modelling constrained against in vivo data from patients with instrumented knee implants allowed us to assess internal loads in femur and tibia. These internal forces were associated with the clinical outcome of fracture healing in a relevant cohort of 178 extra-articular femur and tibia fractures in patients using a retrospective approach. Results: Mean peak forces differed with femoral compression (1,330-1,936 N at mid-shaft) amounting to about half of tibial compression (2,299-5,224 N). Mean peak bending moments in the frontal plane were greater in the femur (71-130 Nm) than in the tibia (from 26 to 43 Nm), each increasing proximally. Bending in the sagittal plane showed smaller mean peak bending moments in the femur (-38 to 43 Nm) reaching substantially higher values in the tibia (-63 to -175 Nm) with a peak proximally. Peak torsional moments had opposite directions for the femur (-13 to -40 Nm) versus tibia (15-48 Nm) with an increase towards the proximal end in both. Femoral fractures showed significantly lower scores in the modified Radiological Union Scale for Tibia (mRUST) at last follow-up (p < 0.001) compared to tibial fractures. Specifically, compression (r = 0.304), sagittal bending (r = 0.259), and frontal bending (r = -0.318) showed strong associations (p < 0.001) to mRUST at last follow-up. This was not the case for age, body weight, or localisation alone. Discussion: This study showed that moments in femur and tibia tend to decrease towards their distal ends. Tibial load components were influenced by knee flexion angle, especially at push-off, while static frontal alignment played a smaller role. Our results indicate that femur and tibia are loaded differently and thus require adapted fracture fixation considering load components rather than just overall load level.
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OBJECTIVE: Opioid stewardship programs combine clinical, regulatory, and educational interventions to minimize inappropriate opioid use and prescribing for orthopedic and spine surgery. Most evaluations of stewardship programs quantify effects on prescriber behavior, whereas patient-relevant outcomes have been relatively neglected. The authors evaluated the impact of an opioid stewardship program on perioperative opioid consumption, prescribing, and related clinical outcomes after multilevel lumbar fusion. METHODS: The study was based on a retrospective, quasi-experimental, pretest-posttest design in 268 adult patients who underwent multilevel lumbar fusion in 2016 (preimplementation, n = 141) or 2019 (postimplementation, n = 127). The primary outcome was in-hospital opioid consumption (morphine equivalent dose [MED], mg). Secondary outcomes included numeric rating scale pain scores (0-10), length of stay (LOS), incidence of opioid-induced side effects (gastrointestinal, nausea/vomiting, respiratory, sedation, cognitive), and preoperative and discharge prescribing. Outcomes were measured continuously during the hospital admission. Differences in outcomes between the epochs were assessed in bivariable (Wilcoxon signed-rank or Fisher's exact tests) and multivariable (Wald's chi-square test) analyses. RESULTS: In bivariable analyses, there were significant decreases in preoperative opioid use (46% vs 28% of patients, p = 0.002), preoperative opioid prescribing (MED 30 mg [IQR 20-60 mg] vs 20 mg [IQR 11-39 mg], p = 0.003), in-hospital opioid consumption (MED 329 mg [IQR 188-575 mg] vs 199 mg [100-372 mg], p < 0.001), the incidence of any opioid-related side effect (62% vs 50%, p = 0.03), and discharge opioid prescribing (MED 90 mg [IQR 60-135 mg] vs 60 mg [IQR 45-80 mg], p < 0.0001) between 2016 and 2019. There were no significant differences in postanesthesia care unit pain scores (4 [IQR 3-6] vs 5 [IQR 3-6], p = 0.33), nursing floor pain scores (4 [IQR 3-5] vs 4 [IQR 3-5], p = 0.93), or total LOS (118 hours [IQR 81-173 hours] vs 103 hours [IQR 81-132 hours], p = 0.21). On multivariable analysis, the opioid stewardship program was significantly associated with decreased discharge prescribing (Wald's chi square = 9.45, effect size -52.4, 95% confidence interval [CI] -86 to -19.0, p = 0.002). The number of lumbar levels fused had the strongest effect on total opioid consumption during the hospital stay (Wald's chi square = 16.53, effect size = 539, 95% CI 279.1 to 799, p < 0.001), followed by preoperative opioid use (Wald's chi square = 44.04, effect size = 5, 95% CI 4 to 7, p < 0.001). CONCLUSIONS: A significant decrease in perioperative opioid prescribing, consumption, and opioid-related side effects was found after implementation of an opioid stewardship program. These gains were achieved without adverse effects on pain scores or LOS. These results suggest the major impact of opioid stewardship programs for spine surgery may be on changing prescriber behavior.
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The isolation of chondrocytes from human articular cartilage for single-cell RNA sequencing requires extensive and prolonged tissue digestion at 37 C. Modulations of the transcriptional activity likely take place during this period such that the transcriptomes of isolated human chondrocytes no longer match their original status in vivo. Here, we optimized the human chondrocyte isolation procedure to maximally preserve the in vivo transcriptome. Cartilage tissues were transferred into a hypoxia chamber (4% O2) immediately after being removed from OA patients and minced finely. Collagenase II at concentrations of 0.02%, 0.1%, 0.25%, 0.5%, 1%, and 2% was applied for 0.5, 1, 2, 4, and 18 h to digest the minced tissue. Actinomycin D (ActD) was added to test its capacity in stabilizing the transcriptome. Cell yield, viability, cell size, and transcriptome were determined using counter chamber, flow cytometry, and RNA sequencing (RNA-seq). Collagenase II at 2% concentration released small chondrocytes from cartilage matrix during the first digestion hour and started to release large cells thereafter, reaching a complete release at 4 h. During 4-h digestions, collagenase II at 2% and 1% but not at lower concentrations yielded maximal release also of the large chondrocyte population. RNA-seq analysis revealed that a 4-h digestion period with 1% or 2% collagenase II plus Actinomycin D optimally preserved the transcriptome. Thus, this study provides an isolation protocol for single chondrocytes from human articular cartilage optimized for transcriptome preservation and RNA-seq analysis.
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BACKGROUND CONTEXT: Studies have shown that site-specific bone density measurements had more predictive value for complications than standard whole-region measurements. Recently, MRI-based assessments of vertebral bone quality (VBQ) were introduced. However, there have been few studies that investigate the association between site-specific MRI bone assessment and osteoporosis-related complications in patients undergoing lumbar interbody fusion. In this work, we created a novel site-specific MRI-based assessment of the endplate bone quality (EBQ) and assessed its predictive value for severe cage subsidence following standalone lateral lumbar interbody fusion (SA-LLIF). PURPOSE: To investigate the predictive value of a novel MRI-based bone assessment for severe cage subsidence after SA-LLIF. STUDY DESIGN/SETTING: Retrospective cohort study. PATIENT SAMPLE: Patients who underwent SA-LLIF from 2008 to 2019 at a single, academic institution with available preoperative lumbar CT and T1-weighted MRIs. OUTCOME MEASURES: Association between EBQ and severe subsidence after SA-LLIF. METHODS: We retrospectively reviewed the records of SA-LLIF patients treated between 2008 and 2019. EBQ was measured using preoperative non-contrast T1-weighted MRIs of the lumbar spine. EBQ was defined as the average value of signal intensity of both endplates divided by that of the cerebrospinal fluid space at the level of L3. Bivariate and multivariable analyses with generalized linear mixed models were performed and set binary severe subsidence as the outcome. RESULTS: Two hundred five levels in 89 patients were included. Fifty levels (24.4%) demonstrated severe subsidence. Bone mineral density measured by quantitative computed tomography was significantly lower in the subsidence group. Both VBQ and EBQ were significantly higher in the subsidence group. The EBQ plus Modic change (MC) model demonstrated that the effect of EBQ was independent of MC. In multivariate analyses adjusted with QCT-vBMD, EBQ showed a significant association with cage subsidence whereas VBQ only showed a marginal trend. The EBQ-based prediction model for severe subsidence showed better goodness of fit compared to the VBQ-based model. CONCLUSIONS: High EBQ was an independent factor for severe cage subsidence after SA-LLIF and the EBQ-based model showed better goodness of fit compared to VBQ- or MC-based models. EBQ assessment before SA-LLIF may provide insight into a patient's risk for severe subsidence.
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Fusión Vertebral , Humanos , Estudios Retrospectivos , Fusión Vertebral/efectos adversos , Fusión Vertebral/métodos , Vértebras Lumbares/diagnóstico por imagen , Vértebras Lumbares/cirugía , Región Lumbosacra/cirugía , Imagen por Resonancia MagnéticaRESUMEN
The objective of this study is to determine the bone mineral density (BMD) changes in adjacent vertebra following anterior cervical discectomy and fusion (ACDF). Consecutive patients undergoing ACDF with available preoperative and postoperative computed tomography (CT) imaging were included. Quantitative CT measurements of screw-free cervical and first thoracic vertebra were performed. Comparisons between pre- and postoperative BMD in the vertebrae one or two levels above the upper instrumented vertebra (UIV + 1, UIV + 2) and one level below the lowest instrumented vertebra (LIV + 1) were assessed. Seventy-two patients (men, 66.7%) met the inclusion criteria. The patient population was 91.7% Caucasian with a mean age of 55.0 years. The mean interval (±SD) between surgery and secondary CT was 157 ± 23 days. Preoperative BMD (±SD) in UIV + 1 was 300.6 ± 66.2 mg/cm3 . There was a significant BMD loss of 1.5% at UIV + 1 after surgery, resulting in a postoperative BMD of 296.2 ± 64.8 mg/cm3 (p = .029). At UIV + 2 and LIV + 1, no significant differences between pre- and postoperative BMD (304.7 ± 75.7 mg/cm3 vs. 299.8 ± 74.3 mg/cm3 , 197.3 ± 50.4 mg/cm3 vs. 200.8 ± 48.7 mg/cm3 , p = .113 and p = .078, respectively) were observed. Clinical significance Our results demonstrate a small BMD decrease of 1.5% at UIV + 1. This suggests that the effect of ACDF surgery on the adjacent levels might be smaller compared to the previously described lumbar BMD loss of 10%-20% following posterior lumbar fusion procedures.
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Fusión Vertebral , Vértebras Cervicales/diagnóstico por imagen , Vértebras Cervicales/cirugía , Humanos , Vértebras Lumbares/diagnóstico por imagen , Vértebras Lumbares/cirugía , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Fusión Vertebral/efectos adversos , Fusión Vertebral/métodos , Vértebras Torácicas/cirugíaRESUMEN
STUDY DESIGN: Retrospective descriptive study. OBJECTIVE: The aim of this study was to create topographical maps of occipital bone thickness and venous sinus (VS) presence to assess the risks of screw insertion in four commercially available occipital plates. SUMMARY OF BACKGROUND DATA: Craniocervical junction instability and deformity are serious pathological conditions that require posterior fixation of the occipital bone to the cervical vertebrae. Insertion of occipital bone screws requires evaluation of both occipital bone thickness for effective internal fixation and intracranial VS presence for vascular injury prevention. Despite the surgical risks, there is a paucity of research on safe screw placement. METHODS: We created a matrix of 231 standardized measurement points to analyze the occipital bone thickness and VS presence in cervical spine CT angiograms. These measurements were used to create topographical maps of occipital bone thickness and likelihood of VS presence, which we then compared to the screw hole configurations of four occipital plates. RESULTS: Hundred patients were assessed. Maximum occipital bone thickness of 13.9â±â3.3âmm was midline in the occipital bone, 45âmm from the foramen magnum, around the external occipital protuberance (EOP). Regions with thicknesses >8âmm were 2âcm lateral to the EOP at the level of the superior nuchal line and 2.5âcm inferior to the EOP. The area with the highest VS presence rate was around the EOP and the superior nuchal line. The right transverse VS was more prominent in both sexes. CONCLUSION: There is a limited area of the occipital bone with thicknesses for enough screw purchase. Previous studies have shown 8âmm as the minimum screw length to reduce the risk of implant failure. In our analysis, only "T"-shaped plates had configurations with thicknesses >8âmm for each screw hole. For every screw hole in the analyzed occipital plates, there was a possibility of VS presence ranging from 8% to 33%.Level of Evidence: 5.
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Angiografía por Tomografía Computarizada , Fusión Vertebral , Angiografía , Tornillos Óseos , Vértebras Cervicales/diagnóstico por imagen , Vértebras Cervicales/cirugía , Femenino , Humanos , Masculino , Hueso Occipital/diagnóstico por imagen , Hueso Occipital/cirugía , Estudios Retrospectivos , Tomografía Computarizada por Rayos XRESUMEN
STUDY DESIGN: Retrospective observational study. OBJECTIVE: The aim of this study was to investigate the spinal cord safety margins for C2 instrumentation. SUMMARY OF BACKGROUND DATA: Intraoperative spinal cord injury during C2 spine surgery is a rare, but potentially life-threatening complication. Preoperative planning for C2 instrumentation mainly focuses on C2 pedicle bony dimensions on CT and the vertebral artery location and few studies have evaluated C2 spinal cord safety margins. METHODS: We measured two distances in C2 bilaterally: C2 pedicle to dura distance (P-D), defined as a transverse line that measured the shortest distance between the medial wall of the C2 pedicle and the dural sac, and C2 pedicle to spinal cord (P-SC), defined as a transverse line that measured the shortest distance between the medial wall of the C2 pedicle and spinal cord. We defined the distances >4âmm as safe for instrumentation. RESULT: A total of 146 patients (mean age 71.2, 50.7% female) were included. The average distances were 5.5âmm for C2 left PD, 5.9âmm for C2 right P-D, 10.1âmm for C2 left P-SC, and 10.6âmm for C2 right P-SC. Twenty-eight (21.4%) patients had C2 P-D distances <4âmm and of those two (7%) patients had distances <2âmm. There were more female patients with C2 P-D distances under 4âmm compared to males. No patient had C2 P-SC distances <4âmm. CONCLUSION: We demonstrated that around 20% of patients had C2 P-D distance <4âmm, but no patient had C2 P-SC distance <4âmm. Since a lateral misplacement can lead to a potentially fatal vertebral artery injury, medial screw trajectory is recommended for C2 pedicle instrumentation with consideration of these safety margins.Level of Evidence: 3.
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Tornillos Pediculares , Fusión Vertebral , Tornillos Óseos , Vértebras Cervicales , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Médula Espinal/diagnóstico por imagen , Fusión Vertebral/efectos adversos , Arteria VertebralRESUMEN
BACKGROUND CONTEXT: The importance of bone status assessment in spine surgery is well recognized. The current gold standard for assessing bone mineral density is dual-energy X-ray absorptiometry (DEXA). However, DEXA has been shown to overestimate BMD in patients with spinal degenerative disease and obesity. Consequently, alternative radiographic measurements using data routinely gathered during preoperative evaluation have been explored for the evaluation of bone quality and fracture risk. Opportunistic quantitative computed tomography (QCT) and more recently, the MRI-based vertebral bone quality (VBQ) score, have both been shown to correlate with DEXA T-scores and predict osteoporotic fractures. However, to date the direct association between VBQ and QCT has not been studied. PURPOSE: The objective of this study was to evaluate the correlation between VBQ and spine QCT BMD measurements and assess whether the recently described novel VBQ score can predict the presence of osteopenia/osteoporosis diagnosed with QCT. STUDY DESIGN/SETTING: Cross-sectional study using retrospectively collected data. PATIENT SAMPLE: Patients undergoing lumbar fusion from 2014-2019 at a single, academic institution with available preoperative lumbar CT and T1-weighted MRIs were included. OUTCOME MEASURES: Correlation of the VBQ score with BMD measured by QCT, and association between VBQ score and presence of osteopenia/osteoporosis. METHODS: Asynchronous QCT measurements were performed. The average L1-L2 BMD was calculated and patients were categorized as either normal BMD (>120 mg/cm3) or osteopenic/osteoporotic (≤120 mg/cm3). The VBQ score was calculated by dividing the median signal intensity of the L1-L4 vertebral bodies by the signal intensity of the cerebrospinal fluid on midsagittal T1-weighted MRI images. Inter-observer reliability testing of the VBQ measurements was performed. Demographic data and the VBQ score were compared between the normal and osteopenic/osteoporotic group. To determine the area-under-curve (AUC) of the VBQ score as a predictor of osteopenia/osteoporosis receiver operating characteristic (ROC) analysis was performed. VBQ scores were compared with QCT BMD using the Pearson's correlation. RESULTS: A total of 198 patients (53% female) were included. The mean age was 62 years and the mean BMI was 28.2 kg/m2. The inter-observer reliability of the VBQ measurements was excellent (ICC of 0.90). When comparing the patients with normal QCT BMD to those with osteopenia/osteoporosis, the patients with osteopenia/osteoporosis were significantly older (64.9 vs. 56.7 years, p<.0001). The osteopenic/osteoporotic group had significantly higher VBQ scores (2.6 vs. 2.2, p<.0001). The VBQ score showed a statistically significant negative correlation with QCT BMD (correlation coefficient = -0.358, 95% CI -0.473 - -0.23, p<.001). Using a VBQ score cutoff value of 2.388, the categorical VBQ score yielded a sensitivity of 74.3% and a specificity of 57.0% with an AUC of 0.7079 to differentiate patients with osteopenia/osteoporosis and with normal BMD. CONCLUSIONS: We found that the VBQ score showed moderate diagnostic ability to differentiate patients with normal BMD versus osteopenic/osteoporotic BMD based on QCT. VBQ may be an interesting adjunct to clinically performed bone density measurements in the future.
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Enfermedades Óseas Metabólicas , Osteoporosis , Fusión Vertebral , Absorciometría de Fotón/métodos , Densidad Ósea , Enfermedades Óseas Metabólicas/diagnóstico por imagen , Estudios Transversales , Femenino , Humanos , Vértebras Lumbares/diagnóstico por imagen , Vértebras Lumbares/cirugía , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Osteoporosis/diagnóstico por imagen , Reproducibilidad de los Resultados , Estudios Retrospectivos , Fusión Vertebral/efectos adversosRESUMEN
Traumatic spinal cord injury (TSCI), commonly caused by high energy trauma in young active patients, is frequently accompanied by traumatic brain injury (TBI). Although combined trauma results in inferior clinical outcomes and a higher mortality rate, the understanding of the pathophysiological interaction of co-occurring TSCI and TBI remains limited. This review provides a detailed overview of the local and systemic alterations due to TSCI and TBI, which severely affect the autonomic and sensory nervous system, immune response, the blood-brain and spinal cord barrier, local perfusion, endocrine homeostasis, posttraumatic metabolism, and circadian rhythm. Because currently developed mesenchymal stem cell (MSC)-based therapeutic strategies for TSCI provide only mild benefit, this review raises awareness of the impact of TSCI-TBI interaction on TSCI pathophysiology and MSC treatment. Therefore, we propose that unravelling the underlying pathophysiology of TSCI with concomitant TBI will reveal promising pharmacological targets and therapeutic strategies for regenerative therapies, further improving MSC therapy.
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Lesiones Traumáticas del Encéfalo/complicaciones , Lesiones Traumáticas del Encéfalo/fisiopatología , Encéfalo/patología , Trasplante de Células Madre Mesenquimatosas , Traumatismos de la Médula Espinal/fisiopatología , Traumatismos de la Médula Espinal/terapia , Regeneración de la Medula Espinal , Ritmo Circadiano/fisiología , HumanosRESUMEN
BACKGROUND: Anterior cervical discectomy and fusion (ACDF) is a safe and effective procedure but has approach-related complications like postoperative dysphagia and dysphonia (PDD). Patient-reported outcome measures including the Hospital for Special Surgery Dysphagia and Dysphonia Inventory (HSS-DDI) have been used for the assessment of PDD. Various factors have been described that affect ACDF outcomes, and our aim was to investigate the effect of workers' compensation (WC) status. METHODS: We included patients who underwent ACDF from 2015 to 2018 stratified according to insurance status: WC/non-WC. PDDs were assessed using the HSS-DDI score. We conducted logistic regression analyses. Statistical significance was set at P < 0.05. RESULTS: We included 287 patients, 44 (15.33%) WC and 243 (84.67%) non-WC. A statistical comparison revealed a clinically relevant difference in the HSS-DDI total score and both subdomains (P = 0.015; dysphagia P = 0.021; dysphonia P = 0.002). Additional logistic regression analysis adjusting for preoperative Neck Disability Index scores resulted in no clinically relevant differences in the HSS-DDI total score and both subdomains (total score P = 0.420; dysphagia P = 0.531; dysphonia 0.315). CONCLUSIONS: WC status was associated with a worse HSS-DDI score but could not be shown to be an independent risk factor for PDD. The preoperative NDI score was a strong predictor for PDD with a clinically relevant difference in the HSS DDI score (P < 0.0001). Surgeon awareness of risk factors for PDD such as WC status, even if it could not be shown as independent, is important as it may influence surgical decision making and managing patient expectations.
Asunto(s)
Vértebras Cervicales/cirugía , Trastornos de Deglución/epidemiología , Trastornos de Deglución/etiología , Disfonía/etiología , Complicaciones Posoperatorias/epidemiología , Fusión Vertebral/efectos adversos , Indemnización para Trabajadores/estadística & datos numéricos , Adulto , Anciano , Toma de Decisiones Clínicas , Bases de Datos Factuales , Evaluación de la Discapacidad , Discectomía , Femenino , Humanos , Cobertura del Seguro , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Puntaje de Propensión , Estudios Prospectivos , Factores de RiesgoRESUMEN
BACKGROUND: The preoperative assessment of C2 morphology is important for safe instrumentation. Sclerotic changes are often seen in C2 pedicles. Evaluating the diameter measurements solely might not accurately assess the safety of screw insertion. We have proposed a novel grading system of the C2 pedicle that includes sclerosis and evaluated the predictive value of this grading system with the surgeon's safety evaluation. METHODS: We reviewed and measured the dimensional values in 220 cervical computed tomography angiograms. Additionally, we used a grading system that divides the findings into 5 grades according to the width measurement and degree of sclerosis in the C2 pedicle. Two spine surgeons independently classified the pedicles as follows: safe (minimal risk of pedicle violation), caution needed (caution to minimize pedicle violation), or dangerous (a high risk of pedicle violation). Finally, we compared the measurements and the surgeons' safety assessments. RESULTS: A total of 411 pedicles of 203 patients (mean age, 69.5 years; 49.5% women) were included. Of the 411 C2 pedicles, 170 were classified as high risk by ≥1 surgeon. Between the dimensional measurements and grading system, the sclerotic grade showed the best predictive value. CONCLUSIONS: We have introduced a novel tool to evaluate the safety of C2 pedicle screw placement. Our results suggest that our pedicle width-sclerosis grading system is reproducible and predicts the surgeon's assessment of safe screw placement better than C2 pedicle diametrical measurements alone.
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Vértebra Cervical Axis/diagnóstico por imagen , Procedimientos Neuroquirúrgicos , Tornillos Pediculares , Esclerosis/clasificación , Cuerpo Vertebral/diagnóstico por imagen , Anciano , Vértebra Cervical Axis/patología , Angiografía por Tomografía Computarizada , Femenino , Humanos , Masculino , Tamaño de los Órganos , Cuidados Preoperatorios , Cuerpo Vertebral/patologíaRESUMEN
BACKGROUND CONTEXT: It has been reported in previous studies that a decreased bone mineral density (BMD) as measured by dual X-ray absorptiometry (DXA) is associated with subsidence. However, there is limited research on the role of volumetric BMD (vBMD) as measured by quantitative computed tomography (QCT). Further, metabolic conditions such as obesity and type 2 diabetes have been associated with poor bone quality, but the impact of these metabolic conditions on on subsidence rates following lateral lumbar interbody fusion (LLIF) remains unclear. As such, risk factors for subsidence following LLIF is an area of ongoing research. PURPOSE: The purpose of this study is to identify risk factors for subsidence following LLIF with a focus on metabolic conditions and vBMD as measured by QCT. STUDY DESIGN/SETTING: Retrospective cohort study at a single academic institution. PATIENT SAMPLE: Consecutive patients undergoing LLIF with or without posterior screws from 2014 to 2019 at a single academic institution who had a pre-operative CT and radiological imaging including radiographs or CT scans between 5 and 14 months post-operatively to assess for cage subsidence. OUTCOME MEASURE: Subsidence prevalence following LLIF. METHODS: We reviewed patients undergoing LLIF with or without posterior screws from 2014 to 2019 with a follow-up ≥5 months. Cage subsidence was assessed using the grading system by Marchi et al. Endplate volumetric BMD (EP-vBMD), vertebral bone volumetric BMD (VB-vBMD), BMI, and diabetes status were measured. Univariable analysis and multivariable logistic regression analyses with a generalized mixed model were conducted. Ad hoc analysis, including receiver operative characteristic curve analysis, was used for identifying the cut-off values in significant continuous variables for subsidence. Chi-Squared and ANOVA tests were used for categorical comparisons. RESULTS: Five hundred sixty-seven levels in 347 patients were included in the final analysis. Mean age (± SD) was 61.7 ± 11.1yrs, 50.3% were male, and 89.6% were Caucasian. Subsidence was observed in 160 levels (28.2%). Multivariable analysis demonstrated an absence of posterior screws [OR = 2.854 (1.483 - 5.215), p=.001] and decreased EP-vBMD [0.996 (0.991 - 1.000), p=.032] were associated with an increased risk of subsidence. Increased BMI and diabetes status were not associated with increased rates of subsidence. Patients without posterior screws and low EP-vBMD experienced subsidence at 44.9% of levels. CONCLUSIONS: Our results demonstrated that decreased EP-vBMD and standalone status were significantly associated with increased rates of subsidence following LLIF independent of BMI or diabetes status. Further analysis demonstrated that patients with a decreased EP-vBMD and without posterior screws experienced subsidence nearly 2.5 times higher than patients with no risk factors. In patients with a low EP-vBMD undergoing LLIF, posterior screws should be considered.
Asunto(s)
Diabetes Mellitus Tipo 2 , Fusión Vertebral , Anciano , Densidad Ósea , Análisis Factorial , Humanos , Vértebras Lumbares/diagnóstico por imagen , Vértebras Lumbares/cirugía , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Fusión Vertebral/efectos adversosRESUMEN
STUDY DESIGN: Retrospective clinical study. PURPOSE: To describe postoperative height changes and identify the predictive factors of spinal height (SH) changes among patients with adult spinal deformity (ASD) who underwent circumferential lumbar fusion with instrumentation. OVERVIEW OF LITERATURE: Postoperative height changes remain an important issue after spinal fusion surgery that affects the overall satisfaction with surgery. Previous studies of postoperative height change have focused exclusively on young patients with adolescent idiopathic scoliosis (AIS). METHODS: We retrospectively reviewed the clinical and imaging data of ASD patients who underwent lumbar corrective circumferential fusion of ≥3 levels (n=106). SH was defined as the vertical distance between C2 and S1 on a standing lateral image. As potential predictors of postoperative height change, the number of lateral lumbar interbody fusion (LLIF) levels, change in spino-pelvic parameters, total number of levels fused, and pedicle subtraction osteotomies (PSO) were documented. Univariate and multivariate linear regression analyses were performed to identify the predictors of postoperative height change. RESULTS: The mean SH change was -2.39±50.8 mm (range, -160 to 172 mm). The univariate analyses showed that the number of LLIF levels (coefficient=10.9, p=0.03), the absolute coronal vertical axis change (coefficient=0.6, p=0.01), and the absolute Cobb angle change (coefficient=-0.9, p=0.03) were significant predictors for height change. Patients with PSOs (n=14) tended to have a shorter height postoperatively (coefficient=-26.1); however, this difference was not significant (p=0.07). Multivariate analyses conducted with variables of p<0.20 showed that pelvic tilt (PT) change is an independent contributor to SH change (coefficient=-0.99, p=0.04, R2=0.11). CONCLUSIONS: Utilizing a modified definition of SH used in previous AIS studies, we demonstrated that patients with ASD lose SH postoperatively and that PT change was an independent contributor of SH change.
RESUMEN
BACKGROUND CONTEXT: The thoracic spine is a common location for vertebral fractures as well as instrumentation failure after long spinal fusion procedures. The association between those complications and bone mineral density (BMD) are well recognized. Due to the overlying sternum and ribs in the thoracic spine, projectional BMD assessment tools such as dual energy x-ray absorptiometry (DXA) are limited to the lumbar spine. Quantitative computed tomography circumvents several shortcomings of DXA and allows for level-specific BMD measurements. Studies comprehensively quantifying BMD of the entire thoracic spine in patients undergoing spine surgery are limited. PURPOSE: The objective of this study was: (1) to assess the reliability of thoracic QCT measurements, (2) to determine possible level-specific BMD variation throughout the thoracic spine and (3) to assess the correlation between BMDs of the T1-T12 spinal levels. STUDY DESIGN/SETTING: Cross-sectional observation study. PATIENT SAMPLE: Patients undergoing spine surgery from 2016-2020 at a single, academic institution with available preoperative CT imaging of the thoracic spine were included in this study. OUTCOME MEASURES: The outcome measure was BMD measured by QCT. METHODS: Patients undergoing spine surgery from 2016-2020 at a single, academic institution with available preoperative CT imaging of the thoracic spine were included in this study. Subjects with previous instrumentation at any thoracic level, concurrent vertebral fractures, a Cobb angle of more than 20 degrees, or incomplete thoracic spine CT imaging were excluded. Asynchronous quantitative computed tomography (QCT) measurements of T1-T12 were performed. To assess inter- and intra-observer reliability, a validation study was performed on 120 vertebrae in 10 randomly selected patients. The interclass correlation coefficient (ICC) was calculated. A pairwise comparison of BMD was conducted and correlations between each thoracic level were evaluated. The statistical significance level was set at p<.05. RESULTS: 60 patients (men, 51.7%) met inclusion criteria. The study population was 90% Caucasian with a mean age of 62.2 years and a mean BMI of 30.2 kg/m2. The inter- and intra-observer reliability of the thoracic QCT measurements was excellent (ICC of 0.97 and 0.97, respectively). The trabecular BMD was highest in the upper thoracic spine and decreased in the caudal direction (T1 = 182.3 mg/cm3, T2 = 168.1 mg/cm3, T3 = 163.5 mg/cm3, T4 = 164.7 mg/cm3, T5 = 161.4 mg/cm3, T6 = 152.5 mg/cm3, T7 = 143.5 mg/cm3, T8 = 141.3 mg/cm3, T9 = 143.5 mg/cm3, T10 = 145.1 mg/cm3, T11 = 145.3 mg/cm3, T12 = 133.6 mg/cm3). The BMD of all thoracic levels cranial to T6 was statistically higher than the BMD of all levels caudal to T6 (p < .001). Nonetheless, significant correlations in BMD among all measured thoracic levels were observed, with a Pearson's correlation coefficient ranging from 0.74 to 0.97. CONCLUSIONS: There is significant regional BMD variation in the thoracic spine depending on spinal level. This BMD variation might contribute to several clinically relevant phenomena. First, vertebral fractures occur most commonly at the thoracolumbar junction including T12. In addition to mechanical reasons, these fractures might be partially attributed to thoracic BMD that is lowest at T12. Second, the optimal upper instrumented vertebra (UIV) for stopping long fusions to the sacrum and pelvis is controversial. The BMD of surgically relevant upper thoracic stopping points (T2-T4) was significantly higher than the BMD of lower thoracic stopping points (T10-T12). Besides stress concentration at the relatively mobile lower thoracic segments, the low BMD at these levels might contribute to previously suggested higher rates of junctional failures with short fusions.