Complications from the surgical treatment of lumbar stenosis

Symptomatic lumbar spinal stenosis, with resultant neurogenic claudication, is a major source of pain and disability in modern societies. Surgical decompression has been shown to improve pain and disability, albeit with an increased risk of adverse events relative to non-operative care. In this review we discuss complications of lumbar stenosis surgery, including cerebrospinal fluid leak, iatrogenic instability, infection, epidural hematoma, as well as positioning-related and medical complications. An emphasis is placed on prevention, diagnosis, and management of these commonly-seen complications.     

Computed Tomography Measured Psoas Cross Sectional Area Is Associated With Bone Mineral Density Measured by Dual Energy X-Ray Absorptiometry

Dual-energy X-ray absorptiometry (DEXA) is the gold standard for osteoporosis screening and diagnosis. However, abdominal conventional computed tomography (CT) scan is widely available and multiple studies validated its use as a screening tool for osteoporosis compared to DEXA. The aim of this study was to determine the reliability of measuring core muscle size at the L3–L4 intervertebral disk space and estimate the relationship between core muscle size and bone mineral density (BMD) measured by DEXA. Retrospective chart review was performed on patients who underwent a DEXA scan for osteoporosis and a conventional abdominal CT scan within one-year apart. Total cross-sectional area (CSA) and Hounsfield Unit (HU) density of core muscles (psoas, paraspinal, and abdominal wall muscles) were measured. The association between psoas, paraspinal, abdominal, and central muscle CSA and Bone Mineral density (BMD) at L3, L4, total Lumbar Spine (LS), and right (R) and left (L) hip was estimated in crude and adjusted for age and sex linear regression models. Sixty patients (37 females, 23 males) met the inclusion criteria. The average interval between DEXA and abdominal CT scans was 3.6 months (range 0.1–10.2). Psoas muscle density was significantly positively associated with R hip BMD in both crude and adjusted models (β = 20.2, p = 0.03; β = 18.5, p = 0.01). We found a significant positive linear association between psoas muscle CSA and HU density with BMD of LS, R, and L hip in both crude and adjusted models. The strongest significant positive linear association was observed between total abdominal CSA and R hip BMD in crude and age and sex adjusted (ß = 85.3, p = 0.01; ß = 63.9, p = 0.02, respectively). CT scans obtained for various clinical indications can provide valuable information regarding BMD. This is the first study investigating association between BMD with central muscle density and CSA, and it demonstrated their significant positive the association.     

Patient physiology influences the MRI-based vertebral bone quality score

BACKGROUND CONTEXTOsteoporosis is a critical issue affecting postmenopausal women and the aging population. A novel magnetic resonance imaging (MRI)-based vertebral bone quality (VBQ) score has been proposed as a method to identify poor bone quality and predict fragility fractures. The diagnostic accuracy of this tool is not well understood.PURPOSETo examine the ability of VBQ to predict osteoporosis and osteopenia, its correlation with dual-energy x-ray absorptiometry (DEXA), and the influence of patient-specific factors upon the score.STUDY DESIGNRetrospective cohort study.PATIENT SAMPLEPatients over the age of 18 with a DEXA scan and noncontrast, T1-weighted MRI of the lumbar spine completed within a 2-year period.OUTCOME MEASURESArea-under-curve (AUC) values of the VBQ score predicting osteopenia and osteoporosis when controlling for patient characteristics.METHODSPatients with noncontrast, T1-weighted MRIs of the lumbar spine and DEXA scans completed within a 2-year time frame were retrospectively reviewed. Patient demographics and medical risk factors for osteoporosis were identified and compared. VBQ scores were measured by two trained researchers and interrater reliability was calculated. Patients were separated into three groups defined by lowest DEXA T-score: Healthy Bone, Osteopenia, and Osteoporosis. analysis of variance, Kruskal-Wallis test, chi-square, t tests, Mann-Whitney U tests, and multivariate linear regression were performed to examine the relationship between patient characteristics, DEXA t-scores, and VBQ scores. Receiver operating characteristic analysis and AUC values were generated for the prediction of osteopenia and osteoporosis.RESULTSA total of 156 patients were included for analysis. Sufficient inter-rater reliability was determined for VBQ measures (intraclass correlation coefficient: 0.81). Most patients were female (83%), postmenopausal (81%), and had hyperlipidemia (64%). Patients with hyperlipidemia and healthy bone density by DEXA had elevated baseline VBQ scores (p<.001) reflective of values seen in osteopenia and osteoporosis. The AUC of the VBQ score predicting osteopenia and osteoporosis changed to be more concordant with DEXA results after controlling for hyperlipidemia (AUC=0.72, 0.70 vs. AUC=0.88, 0.89; p<.001). Sub-analysis of hyperlipidemia subtypes revealed that elevated high-density lipoprotein is associated with elevated VBQ scores.CONCLUSIONSHyperlipidemia increased the MRI-based VBQ score in our healthy bone population. The high signal intensities resembled values seen in osteopenia and osteoporosis, suggesting that physiologic variables which impact bone composition may influence the VBQ score. Specifically, elevated high-density lipoprotein may contribute to this. The microarchitectural changes and the clinical implications of these factors need further exploration.     

Cross-cultural French-Canadian adaptation and psychometric assessment of the Italian Spine Youth Quality of Life (ISYQOL) questionnaire

BACKGROUND CONTEXTIdiopathic scoliosis (IS) can significantly alter the quality of life of adolescents. Some of the available questionnaires in French measuring the quality of life in this population show weak psychometric properties. The newly developed Italian Spine Youth Quality of Life (ISYQOL) questionnaire promises better properties.PURPOSETo provide a French-Canadian version of the ISYQOL and to verify its psychometric characteristics.STUDY DESIGNProspective validation of a cross-cultural adaptation of the ISYQOL questionnaire.PATIENT SAMPLEA total of 111 participants with idiopathic scoliosis (77.5% female, 10–18 years old, mean Cobb angle=28°) were included in the study.OUTCOME MEASUREThe French-Canadian version of the Italian Spine Youth Quality of Life (ISYQOL-F) questionnaire.MATERIALS AND METHODSThe ISYQOL was translated into French using a forward-backward approach. We then verified the understanding of the translated items with two scoliosis experts and 10 adolescents. Afterward, 111 adolescents with IS were recruited by convenience at the scoliosis clinic and they completed the ISYQOL on three occasions (before seeing the specialist, 1 week, and 2 weeks after). Cronbach's alpha, intra-class (ICC), and Pearson correlation coefficients were used to respectively determine internal consistency, test-retest reliability, and concurrent validity with the SRS-22r and SF-12. The standard error of measurement (SEM) and 95% confidence minimal detectable change (MDC₉₅) were also calculated. The ceiling effect was quantified as the percentage of participants who scored the maximum on ISYQOL-F.RESULTSThe ISYQOL-F showed good internal consistency with a Cronbach alpha of 0.81 and 0.85 respectively for items 1–13 (n=55; ISYQOL-F mean score ± SD = 63.9±13.5) and 1–20 (n=56; ISYQOL-F mean score ± SD=60.7±10.3). Test-retest reliability was excellent (ICC_3,1=0.94). The SEM is 3.1 and the MDC₉₅ is 8.6. Correlations between ISYQOL-F and SRS-22r and between ISYQOL-F and SF-12 were moderate for total scores (r=0.56 and 0.50 respectively, p<.001), but low for each domain (between 0.20 and 0.48, p<.05). No significant ceiling effects were observed for ISYQOL-F (≤2.5%). In contrast, ceiling effects ranged from 3.6% to 30.6% for SRS-22r and 0%–68.5% for SF-12.CONCLUSIONSThe internal consistency and reliability of ISYQOL-F are good. The total score correlates moderately with the SRS-22r and SF-12. Unlike SRS-22r, the ISYQOL-F does not appear to have a ceiling effect. The ISYQOL–F may thus be suitable to assess quality of life in a population of French-Canadian adolescents with IS.     

AM-PAC mobility scores predict non-home discharge following adult spinal deformity surgery

BACKGROUND CONTEXTAdult spinal deformity (ASD) surgery requires an extended recovery period and often non-routine discharge. The Activity Measure for Post-Acute Care (AM-PAC) Basic Mobility Inpatient Short Form (6-Clicks) is a prediction tool, validated for other orthopedic procedures, to assess a patient's ability to mobilize after surgery.PURPOSETo assess the thresholds of AM-PAC scores that determine non-home discharge disposition in patients who have undergone ASD surgery.STUDY DESIGNRetrospective reviewPATIENT SAMPLENinety consecutive ASD patients with ≥5 levels fused who underwent surgery from 2015 to 2018, with postoperative AM-PAC scores measured before discharge, were included.OUTCOME MEASURESNon-home discharge dispositionMETHODSPatients with routine home discharge were compared to those with non-home discharge. Bivariate analysis was first conducted to compare these groups by preoperative demographics, comorbidities, radiographic alignment, surgical characteristics, HRQOLs, and AM-PAC measurements. Threshold linear regression with Bayesian information criteria was utilized to identify the optimal cutoffs for AM-PAC scores associated with increased likelihood of non-home discharge. Finally, multivariable analysis controlling for age, sex, comorbidities, levels fused, perioperative complication, and home support was conducted to assess each threshold.RESULTSThirty-six (40%) of 90 patients analyzed had non-home discharge. On bivariate analysis, first AM-PAC score (13.5 vs. 17), last AM-PAC score (17 vs. 20), and AM-PAC change per day (+.387 vs. +1) were all significantly associated with non-home discharge. Threshold regression identified that cutoffs of ≤15 for first AM-PAC score, <17 for last AM-PAC score, and <+0.625 for daily AM-PAC change were associated with non-home discharge. On multivariable analysis, first AM-PAC score ≤15 (odds ratio [OR] 11.28; confidence interval [CI] 2.96-42.99; p<.001), last AM-PAC score <17 (OR 33.57; CI 5.85-192.82; p<.001), and AM-PAC change per day <+0.625 (OR 6.24; CI 2.01-19.43; p<.001) were all associated with increased odds of non-home discharge.CONCLUSIONSFirst AM-PAC score of 15 or less can help predict non-home discharge. A goal of daily AM-PAC increases of 0.625 points toward a final AM-PAC score of 17 can aid in achieving home discharge. The early AM-PAC mobility threshold of ≤15 may help prepare for non-home discharge, while AM-PAC daily changes per day <0.625 and final AM-PAC <17 may provide goals for mobility improvement during the early postoperative period in order to prevent non-home discharge.