Good bone quality is key in avoiding a multitude of afflictions, including osteoporotic fragility fractures and poor outcomes after spine surgery. In patients undergoing instrumented spine fusion, ...bone quality often dictates screw pullout strength, insertional torque, and vertebral body loading properties. While dual-energy X-ray absorptiometry (DEXA) screening is the current method of assessing bone mineral density, the majority of patients do not have DEXA measurements available before undergoing surgical instrumentation.
To create a simple magnetic resonance imaging (MRI)-based score to evaluate bone quality and evaluate the degree to which it correlates with conventional DEXA scores.
Retrospective cohort.
Patients ≥18 years of age undergoing spine surgery for degenerative conditions between 2013 and 2018.
Correlation of the vertebral bone quality (VBQ) score with DEXA T-scores, and association between VBQ score and presence of osteopenia/osteoporosis.
Using noncontrast T1-weighted MRIs of the lumbar spine, the novel VBQ score was calculated for each patient. DEXA T-scores of the femoral neck and total hip were obtained and were compared with patient VBQ scores using linear regression and Pearson's correlation.
Among 68 patients included in this study, 37 were found to have osteopenia/osteoporosis (T-score < −1.0) based on DEXA. A greater VBQ score was significantly associated with the presence of osteopenia/osteoporosis with a predictive accuracy of 81%. VBQ scores correlated moderately with femoral neck T-scores, the lowest overall T-scores of each patient, and correlated fairly with total hip T-scores.
This is the first study to correlate the novel VBQ score obtained from MRIs with DEXA T-score. We found this score to be a significant predictor of healthy versus osteopenic/osteoporotic bone with an accuracy of 81%, and found that VBQ score was moderately correlated with femoral neck and overall lowest T-score.
Cell-free DNA shed by cancer cells has been shown to be a rich source of putative tumor-specific biomarkers. Because cell-free DNA from brain and spinal cord tumors cannot usually be detected in the ...blood, we studied whether the cerebrospinal fluid (CSF) that bathes the CNS is enriched for tumor DNA, here termed CSF-tDNA. We analyzed 35 primary CNS malignancies and found at least one mutation in each tumor using targeted or genome-wide sequencing. Using these patient-specific mutations as biomarkers, we identified detectable levels of CSF-tDNA in 74% 95% confidence interval (95% CI) = 57−88% of cases. All medulloblastomas, ependymomas, and high-grade gliomas that abutted a CSF space were detectable (100% of 21 cases; 95% CI = 88−100%), whereas no CSF-tDNA was detected in patients whose tumors were not directly adjacent to a CSF reservoir (P< 0.0001, Fisher’s exact test). These results suggest that CSF-tDNA could be useful for the management of patients with primary tumors of the brain or spinal cord.
Surgical site infections (SSIs) complicate 1% to 9% of elective spine surgeries. Previously identified risk factors include diabetes mellitus type 2, obesity, and chronic kidney disease. We sought to ...determine whether the use of postoperative surgical site drains is associated with deep SSIs.
We retrospectively identified patients operated for deep SSIs after surgery for degenerative spine pathologies between July 2016 and December 2018. Patients were excluded if the reason for operation was other than deep SSI or if their primary operation was for infection or tumor. Using their index procedure and the electronic medical record, patients were matched to controls based on age, surgical invasiveness, International Classification of Diseases, Tenth Revision, Clinical Modification code, race, and sex. Our main outcome of interest was whether drain retention time, total output, or daily output differed significantly between cases and controls.
We identified 38 patients who met inclusion criteria. Infected patients had a higher body mass index (34.2 vs. 29.9 kg/m
; P = 0.001), higher odds of having diabetes mellitus type 2 (55.3% vs. 18.4%; P = 0.002), longer drain retention time (5.5 vs. 3.5 days; P = 0.02), and longer inpatient stay (9.5 vs. 4.3 days; P = 0.005). Multivariable logistic regression demonstrated that even after controlling for the other risk factors, drain retention time independently predicted postoperative surgical site infection (odds ratio: 1.36; P = 0.02).
Prolonged surgical drain retention correlates with risk of deep SSI after surgery for degenerative spine disease independent of surgical invasiveness, diabetes mellitus type 2 status, and total drain output. Our data suggest early postoperative drain removal may potentially decrease the risk of SSI and shorten duration of hospital stay.
Current evidence suggests that dual-energy x-ray absorptiometry (DXA) scans, the conventional method defining osteoporosis, is underutilized and, when used, may underestimate patient risk for ...skeletal fragility. It has recently been suggested that other imaging modalities may better estimate bone quality, such as the magnetic resonance imaging (MRI)-based vertebral bone quality (VBQ) score which also may assess vertebral compression fracture risk in patients with spine metastases.
To evaluate whether VBQ score is predictive of fragility fractures in a population with pre-existing low bone density and at high-risk for fracture.
Retrospective single-center cohort.
Patients followed at a metabolic bone clinic for osteopenia and/or osteoporosis.
Radiographically-documented new-onset fragility fracture.
Patients with a DXA and MRI scans at the time of consultation and ≥2-year follow-up were included. Details were gathered about patient demographics, health history, current medication use, and serological studies of kidney function and bone turnover. For each patient, VBQ score was calculated using T1-weighted lumbar MRI images. Univariable and multivariable analyses were used to identify the independent predictors of a new fragility fracture. To support the construct validity of VBQ, patient VBQ scores were compared to those in a cohort of 45 healthy adults.
Seventy-two (39.1%) study participants suffered fragility fractures, the occurrence of which was associated with higher VBQ score (3.50 vs. 3.01; p<.001), chronic glucocorticoid use (30.6% vs. 15.2%; p=.014), and a history of prior fragility fracture (36.1% vs. 21.4%; p=.030). Mean VBQ score across all patients in the study cohort was significantly higher than the mean VBQ score in the healthy controls (p<.001). In multivariable analysis, new-onset fracture was independently associated with history of prior fracture (OR=6.94; 95% confidence interval 2.48–19.40; p<.001), higher VBQ score (OR=2.40 per point; 1.30–4.44; p=.003), higher body mass index (OR=1.09 per kg/m²; 1.01–1.17; p=.03), and chronic glucocorticoid use (OR=2.89; 1.03–8.17; p=0.043). Notably, DXA bone mineral density (BMD) was not found to be significantly predictive of new-onset fractures in the multivariable analysis (p=.081).
Here we demonstrate the novel, MRI-derived VBQ score is both an independent predictor of fragility fracture in at-risk patients and a superior predictor of fracture risk than DXA-measured BMD. Given the frequency with which MRIs are obtained by patients undergoing spine surgery consultation, we believe the VBQ score could be a valuable tool for estimating bone quality in order to optimize the management of these patients.
Retrospective cohort study.
To compare short- and long-term outcomes in obese versus nonobese patients undergoing instrumented posterolateral fusion of the lumbar spine.
Obesity is an important ...public health issue due to the negative effects on quality of life. Some studies have shown an association between obesity and higher rates of complications and unfavorable outcomes after spine surgery.
We retrospectively reviewed medical records for all adult patients undergoing 1- to 3-level posterolateral fusion for degenerative spine disease between 1992 and 2012 at a single institution. Patients were divided into obese (body mass index > 30 kg/m) and nonobese cohorts to compare complications, reoperation rates, and symptom resolution at the last follow-up. A regression model was used to estimate relative risk ratios.
During the study period, 732 patients underwent lumbar fusion, with 662 (90.44%) nonobese patients and 70 (9.56%) obese patients in the cohort. Obese patients had significantly higher blood loss intraoperatively (P = 0.002) and a longer average length of stay (P = 0.022). Moreover, obesity was independently associated with a significantly increased risk of developing a postoperative complication (risk ratio 2.14; 95% confidence interval, 1.10-4.16) and surgical site infection (risk ratio 3.11; 95% confidence interval, 1.48-6.52). At the last follow-up, a higher proportion of obese patients had radiculopathy (P = 0.018), motor deficits (P = 0.006), sensory deficits (P = 0.008), and bowel or bladder dysfunction (P = 0.006) than nonobese patients.
In this study, obese patients undergoing lumbar fusion had higher blood loss, longer lengths of stay, higher complication rates, and worse functional outcomes at the last follow-up than nonobese patients. These findings suggest that both surgeons and patients should acknowledge the significantly increased morbidity profile of obese patients after lumbar fusion.
Abstract Background Context Blood transfusions in spine surgery are shown to be associated with increased patient morbidity. The association between transfusion performed using a liberal hemoglobin ...trigger—defined as an intraoperative hemoglobin level of ≥10 g/dL, a postoperative level of ≥8 g/dL, or a whole hospital nadir between 8-10 g/dL—and perioperative morbidity and cost in spine surgery patients is unknown and thus was investigated in this study. Purpose To describe the perioperative outcomes and economic cost associated with liberal hemoglobin trigger transfusion among spine surgery patients. Study Design/Setting Retrospective study. Patient Sample The surgical billing database at our institution was queried for inpatients discharged between 2008 and 2015 after the following procedures: atlantoaxial fusion, anterior cervical fusion, posterior cervical fusion, anterior lumbar fusion, posterior lumbar fusion, lateral lumbar fusion, other procedures, and tumor-related surgeries. In total, 6931 patients were included for analysis. Outcome Measures The primary outcome was composite morbidity which was comprised of: (1) infection (sepsis, surgical-site infection, Clostridium dificile, or drug-resistant infection), (2) thrombotic event (pulmonary embolus, deep venous thrombosis, or disseminated intravascular coagulation), (3) kidney injury, (4) respiratory event, and/or (5) ischemic event (transient ischemic attack, myocardial infarction, or cerebrovascular accident). Methods Data on intraoperative transfusion were obtained from an automated prospectively collected anesthesia data management system. Data on postoperative hospital transfusion was obtained through a Web-based intelligence portal. Based on previous research, we analyzed the data using three definitions of a liberal transfusion trigger in patients who received an RBC transfusion: a liberal intraoperative Hb trigger as a nadir Hb level of 10 g/dL or greater, a liberal postoperative Hb trigger as a nadir Hb level of 8 g/dL or greater, or a whole hospital nadir Hb level of 8-10 g/dL. Variables analyzed included in-hospital morbidity, mortality, length of stay, and total costs associated with a liberal transfusion strategy. Results Among patients with a whole hospital stay nadir hemoglobin between 8 to 10 g/dL, transfused patients demonstrated a longer in-hospital stay (median IQR, 6 5-9 vs. 4 3-6 days; P<0.0001) and a higher perioperative morbidity (n=145, 11.5% vs. n=74, 6.1%; P<0.0001) than those not transfused. Even after adjusting for age, gender, race, ASA class, CCI score, estimated blood loss, baseline hemoglobin value, number of operated levels, and surgery type, logistic regression analysis revealed that patients with a nadir hemoglobin of 8-10 g/dL who were transfused had an independently higher risk of perioperative morbidity (odds ratio OR = 2.12; 95% confidence interval CI, 1.24-3.64; P=0.006). Estimated additional costs associated with liberal trigger use, defined as a transfusion occurring in patients with a whole hospital stay nadir Hb of 8-10 g/dL, ranged from $202,675 to $700,151 annually. Conclusions Transfusion using a liberal trigger is associated with increased morbidity, even after controlling for possible confounders. Our results suggest that modification of transfusion practice may be a potential area for improving patient outcomes and reducing costs.
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