The Validation of the Japanese Version of the Scoliosis Research Society-30 Questionnaire for Adolescent Idiopathic Scoliosis Patients.

Introduction: The Scoliosis Research Society-30 (SRS-30) is a questionnaire originally developed from the SRS-22r questionnaire and is used to evaluate adolescent idiopathic scoliosis (AIS). It comprised questions on five domains: function, pain, self-image, mental health, and satisfaction, with seven additional questions related to postoperative aspects. In addition to the original English version, translations in multiple languages have been effectively applied. Herein, we evaluated the internal consistency and external validity of the Japanese version of the SRS-30 for AIS patients. Methods: Among the 30 questions in SRS-30, the eight additional questions from SRS-22r were translated and back-translated to create a Japanese version of the SRS-30. This translated questionnaire was then used to survey patients with AIS who underwent corrective fusion surgery one year postoperatively. The internal consistency of the responses was evaluated using the Cronbach α coefficient. Additionally, the Spearman correlation analyses were conducted to assess the correlation between the scores obtained from the SRS-30 Japanese version and SRS-22r and the Oswestry Disability Index (ODI) for the overall scale and the five domains. Results: A total of 81 cases (eight males and 73 females; mean age at surgery 14.4 years) were enrolled. The mean preoperative Cobb angle was 51.0°. The Cronbach α coefficient for the overall SRS-30 was 0.861, indicating high internal consistency, while the coefficients for each domain were as follows: function/activity, 0.697; pain, 0.405; self-image/appearance, 0.776; mental health, 0.845; and satisfaction, 0.559. The SRS-30 total score significantly correlated with the SRS-22r total (r=0.945, P<0.001) and the ODI (r=-0.511, P<0.001). The SRS-30 domains highly correlated with the corresponding SRS-22r domains, with correlations ranging from r=0.826 to 0.901 (all P<0.001). Conclusions: The Japanese version of the SRS-30 demonstrated good internal and external validity. The SRS-30 can be used as an assessment tool for health-related quality of life in AIS patients.

Accuracy of Phantomless Calibration of Routine Computed Tomography Scans for Opportunistic Osteoporosis Screening in the Spine Clinic.

STUDY DESIGN: Diagnostic accuracy study. OBJECTIVE: To establish a simple method of phantomless bone mineral density (BMD) measurement by using preoperative lumbar Computed Tomography (CT) scans, and compare the accuracy of reference tissue combinations to diagnose low BMD against uncalibrated Hounsfield units (HUs). SUMMARY OF BACKGROUND DATA: HUs are used as a measure of BMD; however, associations between HU and T-scores vary widely. Quantitative CT (qCT) scans are more accurate, but they require density calibration with an object of known density (phantom), which limits feasibility. As an emerging technique, phantomless (internal) calibration of routine CT scans may provide a good opportunity for screening. METHODS: Patients who were scheduled to undergo lumbar surgery, with a preoperative CT scan, and a dual-energy x-ray absorptiometry (DXA) scan within six months were included. Four tissues were selected for calibration: subcutaneous adipose (A), erector spinae (ES), psoas (P) and aortic blood (AB). The HUs of these tissues were used in linear regression against ground-truth values. Calibrations were performed by using two different internal tissues at a time to maintain simplicity and in-office applicability.Volumetric bone mineral densities (vBMD) derived from internally calibrated CT scans were analyzed for new threshold values for low bone density. Areas under the curve (AUC) were calculated with 95% confidence intervals (CI). RESULTS: 45 patients were included (M/F=10/35, mean age:63.3). Calibrated vBMDs had stronger correlations with DXA T-scores when compared with HUs, with L2 exhibiting the highest coefficients. Calibration by using A and ES with the threshold of 162 mg/cm3 had a sensitivity of 90% in detecting low BMD (AUC=0.671). CONCLUSIONS: This novel method allows simple, in-office calibration of routine preoperative CT scans without the use of a phantom. Calibration using adipose and erector spinae with a threshold of 162 mg/cm3 is proposed for low bone density screening with high sensitivity (90%). LEVEL OF EVIDENCE: Level III.

Comparison of No Tap (two-step) and tapping robotic assisted cortical bone trajectory screw insertion.

Workflow for cortical bone trajectory (CBT) screws includes tapping line-to-line or under tapping by 1 mm. We describe a non-tapping, two-step workflow for CBT screw placement, and compare the safety profile and time savings to the Tap (three-step) workflow. Patients undergoing robotic assisted 1-3 level posterior fusion with CBT screws for degenerative conditions were identified and separated into either a No-Tap or Tap workflow. Number of total screws, screw-related complications, estimated blood loss, operative time, robotic time, and return to the operating room were collected and analyzed. There were 91 cases (458 screws) in the No-Tap and 88 cases (466 screws) in the Tap groups, with no difference in demographics, revision status, ASA grade, approach, number of levels fused or diagnosis between cohorts. Total robotic time was lower in the No-Tap (26.7 min) versus the Tap group (30.3 min, p = 0.053). There was no difference in the number of malpositioned screws identified intraoperatively (10 vs 6, p = 0.427), screws converted to freehand (3 vs 3, p = 0.699), or screws abandoned (3 vs 2, p = 1.000). No pedicle/pars fracture or fixation failure was seen in the No-Tap cohort and one in the Tap cohort (p = 1.00). No patients in either cohort were returned to OR for malpositioned screws. This study showed that the No-Tap screw insertion workflow for robot-assisted CBT reduces robotic time without increasing complications.

Intra-Operative Hypotension is an Important Modifiable Risk Factor for Major Complications in Spinal Fusion Surgery.

STUDY DESIGN: Retrospective observational cohort. OBJECTIVES: This study explores the impact of Intraoperative hypotension (IOH)on post-op complications for major thoracolumbar spine fusion procedures. SUMMARY OF BACKGROUND DATA: IOH with mean arterial pressure (MAP) < 65 mmHg is associated with post-op acute kidney injury (AKI) in general surgery. In spinal deformity surgery, IOH is a contributing factor to MEP changes and spinal cord dysfunction with deformity correction. METHODS: 539 thoracolumbar fusion cases, > 6 surgical levels and > 3 hours duration were identified. Anesthetic/surgical data included OR time, fluid volume, blood loss, blood product replacement and use of vasopressors. Arterial-line based MAP data was collected at 1 min intervals. Cummulative duration of MAP < 65 mmHg was recorded. IOH within the first hour of surgery vs. the entire case was determined. Post-op course and complications including SSI, GI complications, pulmonary complications, MI, DVT, PE, AKI and encephalopathy were noted. Cumulative complications were grouped as none, 1-2 complications, or >3 complications. RESULTS: There was a significant association between occurrence of complications and duration of IOH within the first hour of surgery (8.2 vs. 5.6 min, P<0.001) and across the entire procedure (28.1 vs. 19.3 min, P=0.008). This association persisted for individual major complications including SSI, acute respiratory failure, PE, ileus requiring NGT and post-operative cognitive dysfunction. Comparison of patients with 0 vs. 1-2 vs. 3 or more complications demonstrated that patients with 3 or more complications had a longer duration of IOH in the first hour of the surgery and that patients who had no complications received less vasopressor than patients who had 1-2 or 3 or more complications. CONCLUSION: This study identifies duration of IOH during the first hour of surgery as a previously unrecognized modifiable risk associated with major complications for multi-level lumbar fusion surgery.

Proximal Junctional Degeneration and Failure Modes: A Novel Classification and Clinical Implications.

STUDY DESIGN: Case-control study. OBJECTIVE: To introduce a classification system that will include the major types of degenerative changes and failures related to the proximal junction, and to determine the clinical course and characteristics for the different types of proximal junctional degeneration (PJD). SUMMARY OF BACKGROUND DATA: Proximal junctional kyphosis (PJK) and failures are well recognized after adult spinal fusion, however, a standardized classification is lacking. METHODS: The proposed system identified four different patterns of PJD: Type 1 (multi-level symmetrical collapse), Type 2 (Single adjacent level collapse), Type 3 (fracture) and Type 4 (spondylolisthesis). A single center database was reviewed from 2018 to 2021. Patients ≥18 years of age, who underwent posterior spinal fusion of ≥3 levels with an upper instrumented vertebral level between T8-L2, and a follow-up of ≥2 years were included. Radiographic measurements, revision surgery and time to revision were the primary outcomes. RESULTS: 150 patients were included with a mean age of 65.1 (±9.8) years and a mean follow-up of 3.2 (±1) years. 69 patients (46%) developed significant degenerative changes in the proximal junction, and were classified accordingly. 20 (13%) were Type 1, 17 (11%) were Type 2, 22 (15%) were Type 3 and 10 (7%) were Type 4. Type 3 had a significantly shorter time to revision with a mean of 0.9 (±0.9) years. Types 3 and 4 had greater preoperative sagittal vertical axis, and Types 1 and 3 had greater final follow-up lumbar lordosis. Bone density measured by Hounsfield units showed lower measurements for Type 3. Types 1 and 4 had lower rates of developing PJK. Type 1 had the lowest revision rate with 40% (types 2, 3 and 4 were 77%, 73% and 80%, respectively, P=0.045). CONCLUSION: This novel classification system defines different modes of degeneration and failures at the proximal junction, and future studies with larger sample sizes are needed for validation. LEVEL OF EVIDENCE: 3.

Immediate Postoperative Change in the Upper Instrumented Screw-Vertebra Angle Is a Predictor for Proximal Junctional Kyphosis and Failure.

STUDY DESIGN: Retrospective review. OBJECTIVES: To determine if change in position of upper instrumented vertebral (UIV) screw between intraoperative prone and immediate postoperative standing radiographs is a predictor for proximal junctional kyphosis or failure (PJK/PJF). SUMMARY OF BACKGROUND DATA: Cranially directed UIV screws on post-operative radiographs have been found to be associated with PJK. Change in the screw position between intraoperative and immediate postoperative radiographs has not been studied. METHODS: Patients with posterior fusion ≥3 levels and UIV at or distal to T8, and minimum 2-year follow-up were identified from a single center database. Primary outcomes were radiographic PJK/PJF or revision for PJK/PJF. Demographic, surgical and radiographic variables, including intraoperative screw-vertebra (S-V) angle, change in S-V angle, direction of UIV screw (cranial-neutral-caudal) and rod-vertebra (R-V) angle were collected. RESULTS: 143 cases from 110 patients were included with a mean age of 62.9 years and a follow-up of 3.5 years. 54 (38%) cases developed PJK/PJF, of whom 30 required a revision. Mean S-V angle was -0.9°±5.5° intraoperative and -2.8°±5.5° postoperative. The group with PJK/PJF had a mean S-V angle change of -2.5°±2.4 while the rest had a change of -1.0°±1.6 (P=0.010). When the change in S-V angle was <5°, 33% developed PJK, this increased to 80% when it was ≥5° (P=0.001). Revision for PJK/PJF increased from 16% to 60% when S-V angle changed ≥5° (P=0.001). Regression analysis showed S-V angle change as a significant risk factor for PJK/PJF (P=0.047, OR=1.58) and for revision due to PJK/PJF (P=0.009, OR=2.21). CONCLUSIONS: Change in the S-V angle from intraop prone to immediate postop standing radiograph is a strong predictor for PJK/PJF and for revision. For each degree of S-V angle change, odds of revision for PJK/PJF increases by 2.2x. A change of 5° should alert the surgeon to the likely development of PJK/PJF requiring revision.

A propensity-matched study of patients with symptomatic lumbar spinal stenosis opting for surgery versus not.

Introduction: Although most surgeons treating patients with lumbar spinal stenosis (LSS) believe that surgical treatment is superior to conservative measures, systematics reviews have concluded that no solid evidence support this. Research question: To compare change at 1-year of walking ability, health-related quality of life, leg and back pain in patients with symptomatic LSS referred to a spine surgery clinic who opted for surgery and those who did not. Material and methods: The study included 149 operated and 149 non-operated patients seen by spine surgeons and diagnosed with LSS. The non-operated patients were propensity-matched to a cohort retrieved from the Danish national spine registry. Matching was done on demographics and baseline outcome measures. The outcomes was walking improvement measured by item 4 of the Oswestry Disability Index, EQ-5D-3L, global assessment (GA) of back/leg pain, back and leg pain on the Visual Analogue Scale and the Short Form 36 transition item 2. Results: Less than half of the non-operated reached MCID on EQ-5D-3L, VAS pain legs or VAS pain back where 2/3 of the operated did. The largest difference was VAS back pain where 27.5% of the non-operated reached an MCID of 12 points compared to 71.8% in the operated group. Discussion and conclusion: Surgical treated patients improved better than non-operated on all outcome measures. However, further research is required to compare the effectiveness of surgical decompression with non-operative care for LSS patients.

Measuring quality of recovery (QoR-15) after degenerative spinal surgery: A prospective observational study.

Introduction: The Quality of Recovery (QoR-15) score evaluates patient's recovery after surgery and anesthesia. There is a lack of studies focusing on the patients' quality of recovery in the early post-discharge phase after elective lumbar spine surgery. Research question: We aimed to identify the QoR-15 score in patients who underwent surgery for degenerative low back conditions. Furthermore, we aimed to identify the individual items of the QoR-15 that are crucial for the patients' quality of recovery. Material and methods: The study was conducted at a spine center in Denmark from December 2021 to September 2022. Data were collected, using a mobile health application, preoperatively and at 3 time points after hospital discharge. Descriptive analysis followed by within-subjects longitudinal repeated measures was conducted. The individual items of the QoR-15 score were explored using a heatmap. Results: Data from 46 patients were analysed. The mean QoR-15 sum score at baseline was 105.4 ± 18.3. The mean QoR-15 sum scores were 108.1 ± 19.2 on post-discharge day 1, 118.5 ± 17.4 on day 7, and 120.7 ± 20.9 on day 14. The mean QoR-15 score from day 1 to day 7 improved significantly. Eight of the 15 items influenced the overall QoR-15 score. Discussion and conclusion: This study applied the QoR-15 score in lumbar spine surgery patients. We identified specific items from the QoR-15 scale that are crucial to improving patients' recovery after hospital discharge. Further research is needed to identify specific needs in the post-discharge period in this group of patients.

PROPOSE. Development and validation of a prediction model for shared decision making for patients with lumbar spinal stenosis.

Background: Decompression for lumbar spinal stenosis (LSS) is the most frequently performed spine surgery in Denmark. According to the Danish spine registry DaneSpine, at 1 year after surgery, about 75% of patients experiences considerable pain relief and around 66% improvement in quality of life. However, 25% do not improve very much. We have developed a predictive decision support tool, PROPOSE. It is intended to be used in the clinical conversation between healthcare providers and LSS patients as a shared decision-making aid presenting pros and cons of surgical intervention. This study presents the development and evaluation of PROPOSE in a clinical setting. Methods: For model development, 6.357 LSS patients enrolled in DaneSpine were identified. For model validation, predictor response and predicted outcome was collected via PROPOSE from 228 patients. Observed outcome at 1 year was retrieved from DaneSpine. All participants were treated at 3 Danish spine centers. The outcome measures presented are improvement in walking distance, the Oswestry Disability Index, EQ-5D-3L and leg/back pain on the Visual Analog Scale. Outcome variables were dichotomized into success (1) and failure (0). With the exception of walking distance, a success was defined as reaching minimal clinically important difference at 1-year follow-up. Models were trained using Multivariate Adaptive Regression Splines. Performance was assessed by inspecting confusion matrix, ROC curves and comparing GCV (generalized cross-validation) errors. Final performance of the models was evaluated on independent test data. Results: The walking distance model demonstrated excellent performance with an AUC of 0.88 and a Brier score of 0.14. The VAS leg pain model had the lowest discriminatory performance with an AUC of 0.67 and a Brier score of 0.22. Conclusions: PROPOSE works in a real-world clinical setting as a proof of concept and demonstrates acceptable performance. It may have the potential of aiding shared decision making.

Risk Factors for Medial Breach During Robotic-Assisted Cortical Bone Trajectory Screw Insertion.

OBJECTIVE: We describe the incidence of, and identify the risk factors for, a medial breach of the pedicle wall during robotic-assisted cortical bone trajectory (RA-CBT) screw insertion. METHODS: We analyzed a consecutive series of adult patients who underwent RA-CBT screw placement from January 2019 to July 2022. To assess the pedicle wall medial breach, postoperative computed tomography (CT) images were analyzed. Patient demographic data and screw data were compared between patients with and without a medial breach. The Hounsfield units (HUs) on the L1 midvertebral axial CT scan was used to evaluate bone quality. RESULTS: Of 784 CBT screws in 145 patients, 30 (3.8%) had a medial breach in 23 patients (15.9%). One screw was grade 2, and the others were grade 1. Patients with a medial breach had a lower HU value compared with the patients without a medial breach (123.3 vs. 150.5; P = 0.027). A medial breach was more common in the right than left side (5.5% vs. 2.0%; P = 0.014). More than one half of the screws with a medial breach were found in the upper instrumented vertebra (UIV) compared with the middle construct or lowest instrumented vertebra (6.7% vs. 1.3% vs. 2.7%; P = 0.003). Binary logistic regression showed that low HU values, right-sided screw placement, and UIV were associated with a medial breach. No patients returned to the operating room for screw malposition. No differences were found in the clinical outcomes between patients with and without a medial breach. CONCLUSIONS: The incidence of pedicle wall medial breach was 3.8% of RA-CBT screws in the postoperative CT images. A low HU value measured in the L1 axial image, right-sided screw placement, and UIV were associated with an increased risk of medial breach for RA-CBT screw placement.

Rate of Unexpected Malignancy in Patients Undergoing Percutaneous Vertebroplasty after Implementing a New Scanning Protocol.

STUDY DESIGN: Retrospective quality improvement study. OBJECTIVE: To investigate if the rate of unsuspected malignancy in biopsies in patients with VCF who underwent PVP at the same orthopedic department has changed after implementation of a new MRI scanning protocol. SUMMARY OF BACKGROUND DATA: Discrimination between benign and malign vertebral compression fracture (VCF) can be difficult. However, early diagnosis of malignant VCF is crucial to further treatment and prognosis. An earlier study at an orthopedic department reported a rate of unsuspected malignancy of 4.9% in patients with VCF who underwent percutaneous vertebroplasty (PVP) when biopsies were obtained during the procedure. MRI scanning protocol was changed in this period. METHODS: Retrospective on 427 patients with vertebral compression fracture undergoing PVP from 28th of April 2017 to 28th of April 2022, identifying operated patients from the Danish national DaneSpine registry. Subsequently, individual clinical information was collected in journal records. RESULTS: The rate of unsuspected malignancy was 0.9% (4/427) and the overestimation of malignant VCF was 50% (16/32). CONCLUSION: During the last 5 years, the rate of unsuspected malignancy in patients with VCF undergoing PVP has improved considerably from 4.9% to 0.9%. Furthermore, MRI is over-diagnosing malignancies. Thus, the new scanning procedure is effective in differentiating between benign and malign VCFs. LEVEL OF EVIDENCE: 3.

The Oswestry Disability Index is reflective of pain interference and mobility in children.

PURPOSE: The 9-item Oswestry Disability Index version 2.1a (ODI-9) has never been formally validated in children. Our primary purpose was to evaluate the ODI-9 using the Patient-Reported Outcomes Measurement Information System (PROMIS) Pediatric Pain Interference (PI) and Mobility Computer Adapted Test (CAT) and Pain Catastrophizing Scale for Children (PCS-C) as anchors to determine concurrent validity in children. METHODS: We retrospectively reviewed cross-sectional patient-reported outcomes data using a convenience sample of children referred to a tertiary pediatric orthopedic institution for any spine condition from April 2021 to April 2022. The ODI-9, PI, and Mobility were completed at clinic intake in 2,097 children (1453 girls, 644 boys) aged 14.2 ± 2.6 years (range 5-18 years) during the same visit. The ODI-9 was administered when children or caregivers responded "yes" to the presence of back pain. The PCS-C was administered only when pain intensity was rated as "very severe" or "the worst imaginable" on Item 1 of the ODI-9 (n = 51). RESULTS: Average ODI-9 scores were 18.3% ± 14.8%, indicating minimal disability (ODI-9 ≤ 20%). Moderate, statistically and clinically significant associations were seen between the ODI-9 and PI (r = 0.68, p < 0.001), the ODI-9 and Mobility (r = - 0.68, p < 0.001), and the ODI-9 and PCS-C (r = 0.59, p < 0.001). CONCLUSION: Worse ODI-9 scores correlate with worse PROMIS PI scores, worse PROMIS Mobility scores, and worse PCS-C scores. The associations were moderate (PROMIS PI [r = 0.68], PROMIS Mobility [r = - 0.68], PCS-C [r = 0.59]).

The effect of myelography dye on bone density measurements utilizing Hounsfield units on CT.

OBJECTIVE: Hounsfield unit (HU) measurements of bone density on CT are increasingly used for preoperative planning in spine surgery. Postmyelogram CT is another common preoperative diagnostic study. However, there is no current literature evaluating whether HU measurements on CT are affected by the presence of myelography dye. The purpose of the current study was to determine if the presence of myelography dye affects HU measurements of bone density in CT studies. METHODS: Twenty-nine preoperative spine surgery patients who underwent both standard and postmyelography CT performed within 6 months of each other were identified. HU measurements were obtained from an elliptical region of interest using the available software on a standard PACS. Measurements were obtained on the axial cut at the midvertebral body on all lumbar vertebrae on three separate occasions and an average value was calculated for comparative analysis. A 6-week gap was used between measurements of the CT scans and the CT myelograms to diminish bias. RESULTS: The mean age of the cohort was 69 years and the average BMI was 32 kg/m2. Five patients were male and 24 were female. Six of the patients had instrumentation placed prior to the initial CT scan. The average HU measurements for CT levels L1-5 were 165, 171, 145, 154, and 225, respectively, whereas HU measurements for CT myelography of levels L1-5 were 168, 177, 148, 170, and 239, respectively. Strong correlations were noted between the HU measured on CT and CT myelography for L1 (r2 = 0.951), L2 (r2 = 0.966), L4 (r2 = 0.820), and L5 (r2 = 0.900), and moderate for L3 (r2 = 0.668). CONCLUSIONS: The presence of myelography dye had no clear effect on CT HU measurements of bone density. The results of this study support the use of CT myelograms for bone density assessment in the absence of standard CT images.

Staged circumferential lumbar fusions have less intraoperative complications and shorter operative time with no difference in 30-, 90-, and 1-year complications: a propensity-matched cohort analysis of 190 patients.

BACKGROUND CONTEXT: Circumferential lumbar fusions (cLFs) are becoming more common with increasing and more minimally invasive anterior access techniques. Staging allows reassessment of indirect decompression and alignment prior to the posterior approach, and optimization of OR time management. Safety of staging has been well documented in deformity surgery but has yet to be delineated in less extensive, degenerative cLFs. PURPOSE: The purpose of this study is to compare perioperative complications and outcomes between staged versus single-anesthetic circumferential fusions in the lumbar spine. STUDY DESIGN: Propensity-matched comparative observational cohort. PATIENT SAMPLE: Patients who underwent cLFs for lumbar degenerative disease. OUTCOME MEASURES: In-hospital, 30-day, 90-day, and 1-year complications. METHODS: From 123 patients undergoing single-anesthetic and 154 patients undergoing staged cLF, 95 patients in each group were propensity-matched based on age, sex, BMI, ASA score, smoking, revision, and number of levels. We compared perioperative, 30-day, 90-day, and 1-year complications between the two cohorts. RESULTS: Mean days between stages was 1.58. Single-anesthetic cLF had longer total surgery time (304 vs 240 minutes, p<.001) but shorter total PACU total time (133 vs 196 minutes, p<.001). However, there was no difference in total anesthesia time (368 vs 374 minutes, p=.661) and total EBL (357 vs 320cc, p=.313). Intraoperative complications were nine incidental durotomies in the single-anesthetic and one iliac vein injury in the staged group (9% vs 1%, p=.018). There was no difference of in-hospital (38 vs 31, p=.291), 30-day (16 vs 23, p=.281), 90-day (10 vs 15, p=.391), 1-year complications (9 vs 12, p=.644), and overall cumulative 1-year complications (54 vs 56, p=.883) between the two cohorts. CONCLUSIONS: There is a decrease in total surgical time and intraoperative complications during staged compared with single-anesthetic cLF with no difference in in-hospital, 30-day, 90-day, and 1-year complications between approaches.

Normative Bone Mineral Density Measured on Computed Tomography Scans in Children and Adolescents.

STUDY DESIGN: Retrospective chart review. OBJECTIVE: To provide reference values for Hounsfield unit (HU) measured on computed tomography (CT) scans of children and adolescents. SUMMARY OF BACKGROUND DATA: Spine surgeons increasingly use HU on spine CT as a measure of bone mineral density (BMD). This has not been described in children and adolescents. PATIENTS AND METHODS: Pediatric patients who had a spine CT between 2012 and 2022 were identified. Patients who had more than 1 comorbidity or were syndromic were excluded. Using the bone window, 3 axial images (cephalad, middle, and caudal) of each vertebra were selected. In each axial view, the HU was measured using a "region of interest" (ROI) that included the total cancellous bone area and an ROI excluding the radiolucency present in the posterior vertebral body ("total" vs . "limited"). HU values were compared between total and limited areas and between the axial images at the cephalad, middle, and caudal levels. Each age category data were estimated and stratified. RESULTS: A total of 144 patients (79 females and 65 males) from 2 to 17 years old were included. Mean limited HU was consistently lower than total HU across all images and lumbar levels except for L1. Limited HU taken mid-vertebral body was also consistently lower than those taken cephalad or caudad. Mean limited HU across all ages including all levels was 227 ± 50 (range: 109-357). Stratifying by age showed a gradual decrease in BMD from age 2 to 10 followed by an increase. CONCLUSIONS: This is the first study to measure HU on lumbar CTs in children and adolescents. The technique of measuring BMD in adults should be modified in children by using an ROI that excludes the rarefaction present in the posterior vertebral body. Further studies are needed to evaluate the age-dependent changes in BMD seen in this study.

Performance of the streamlined quality outcomes database web-based calculator: internal and external validation.

BACKGROUND CONTEXT: With an increasing number of web-based calculators designed to provide the probabilities of an individual achieving improvement after lumbar spine surgery, there is a need to determine the accuracy of these models. PURPOSE: To perform an internal and external validation study of the reduced Quality Outcomes Database web-based Calculator (QOD-Calc). STUDY DESIGN: Observational longitudinal cohort. PATIENT SAMPLE: Patients enrolled study-wide in Quality Outcomes Database (QOD) and patients enrolled in DaneSpine at a single institution who had elective lumbar spine surgery with baseline data to complete QOD-Calc and 12-month postoperative data. OUTCOME MEASURES: Oswestry Disability Index (ODI), Numeric Rating Scales (NRS) for back and leg pain, EuroQOL-5D (EQ-5D). METHODS: Baseline data elements were entered into QOD-Calc to determine the probability for each patient having Any Improvement and 30% Improvement in NRS leg pain, back pain, EQ-5D and ODI. These probabilities were compared with the actual 12-month postop data for each of the QOD and DaneSpine cases. Receiver-operating characteristics analyses were performed and calibration plots created to assess model performance. RESULTS: 24,755 QOD cases and 8,105 DaneSpine lumbar cases were included in the analysis. QOD-Calc had acceptable to outstanding ability (AUC: 0.694-0.874) to predict Any Improvement in the QOD cohort and moderate to acceptable ability (AUC: 0.658-0.747) to predict 30% Improvement. QOD-Calc had acceptable to exceptional ability (AUC: 0.669-0.734) to predict Any improvement and moderate to exceptional ability (AUC: 0.619-0.862) to predict 30% Improvement in the DaneSpine cohort. AUCs for the DaneSpine cohort was consistently lower that the AUCs for the QOD validation cohort. CONCLUSION: QOD-Calc performs well in predicting outcomes in a patient population that is similar to the patients that was used to develop it. Although still acceptable, model performance was slightly worse in a distinct population, despite the fact that the sample was more homogenous. Model performance may also be attributed to the low discrimination threshold, with close to 90% of cases reporting Any Improvement in outcome. Prediction models may need to be developed that are highly specific to the characteristics of the population.

Patient expectations impact patient-reported outcomes and satisfaction after lumbar fusion.

BACKGROUND CONTEXT: Prior studies suggest that patient expectations impact postoperative patient-reported outcomes (PROMs). However, no consensus exists on an appropriate expectations tool. PURPOSE: To examine the impact of patient expectations using a modified version of the Oswestry Disability Index (ODI) on clinical outcomes and patient satisfaction 1 year after lumbar fusion for degenerative pathologies. STUDY DESIGN: Prospective longitudinal cohort. PATIENT SAMPLE: Adults undergoing 1 to 2 level lumbar fusion were identified from four tertiaty spine centers. OUTCOME MEASURES: ODI, EuroQol-5D, Numeric rating scales for back and leg pain. METHODS: Preoperatively, patients completed the ODI, as well as a modified ODI reflecting their expected improvement across the 10 ODI items. For example, item 1 in the ODI asks about Pain Intensity at the moment whereas the Expectations ODI asks "One year after surgery, I expect to have…" The difference between this modified ODI score and the baseline ODI score (Baseine ODI minus Expectations ODI) was defined as the Patient Expectation Score. Patients were stratified into tertiles based on their Expectations score into High (HE), Moderate (ME), and Low (LE) Expectations and compared. RESULTS: There were 30 patients in the HE, 35 in the ME, and 26 in the LE Group, with similar demographics and surgical parameters. Patients in the HE group had worse ODI scores preoperatively (54.96 vs 41.42, p<.001) and were expecting a greater improvement in ODI (43.8 vs 13.5, p<.001). There were fewer patients in the HE group (13, 43%) who reported that they were satisfied with the results compared to either the ME (20, 71%) or LE group (22, 85%, p=.041) despite having similar ODI scores and change in ODI scores 1 year postoperatively. CONCLUSION: An expectations tool, linked to a disease-specific measure may provide the clinician with a practical method of assessing a patient's expectation of results after treatment and aid in the shared decision-making during the preoperative surgical process.

Assessment of the External Validity of Dialogue Support for Predicting Lumbar Spine Surgery Outcomes in a US Cohort.

STUDY DESIGN: External validation using prospectively collected data. OBJECTIVES: To determine the model performance of "Dialogue Support" (DS) in predicting outcomes after lumbar spine surgery. SUMMARY OF BACKGROUND DATA: To help clinicians discuss risk versus benefit with patients considering lumbar fusion surgery, DS has been made available online. As DS was created using a Swedish sample, there is a need to study how well DS performs in alternative populations. PATIENTS AND METHODS: Preoperative data from patients enrolled in the Quality Outcomes Database were entered into DS. The probability for each patient to report satisfaction, achieve success (leg pain improvement ≥3), or have no leg pain 12 months after surgery was extracted and compared with their actual 12-month postoperative data. The ability of DS to identify patients in the Quality Outcomes Database who report satisfaction, achieve success, or have no leg pain 12 months after surgery was determined using Receiver operating characteristic curve analysis, goodness-of-fit tests, and calibration plots. RESULTS: There was a significant improvement in all outcomes in 23,928 cases included in the analysis from baseline to 12 months postoperative. Most (84%) reported satisfaction, 67% achieved success, and 44% were pain-free 12 months postoperative. Receiver operating characteristic analysis showed that DS had a low ability to predict satisfaction [area under the curve (AUC) = 0.606], success (AUC = 0.546), and being pain-free (AUC = 0.578) at 12 months postoperative; poor fit for satisfaction (<0.001) and being pain-free ( P = 0.004), but acceptable fit for success ( P = 0.052). Calibration plots showed underestimation for satisfaction and success, but acceptable estimates for being pain-free. CONCLUSION: DS is not directly transferable to predict satisfaction and success after lumbar surgery in a US population. This may be due to differences in patient characteristics, weights of the variables included, or the exclusion of unknown variables associated with outcomes. Future studies to better understand and improve the transferability of these models are needed.

Opioid-sparing Anesthesia Decreases In-hospital and 1-year Postoperative Opioid Consumption Compared With Traditional Anesthesia: A Propensity-matched Cohort Study.

STUDY DESIGN: Propensity-matched cohort. OBJECTIVE: The aim of this study was to determine if opioid-sparing anesthesia (OSA) reduces in-hospital and 1-year postoperative opioid consumption. SUMMARY OF BACKGROUND DATA: The recent opioid crisis highlights the need to reduce opioid exposure. We developed an OSA protocol for lumbar spinal fusion surgery to mitigate opioid exposure. MATERIALS AND METHODS: Patients undergoing lumbar fusion for degenerative conditions over one to four levels were identified. Patients taking opioids preoperatively were excluded. OSA patients were propensity-matched to non-OSA patients based on age, sex, smoking status, body mass index, American Society of Anesthesiologists grade, and revision versus primary procedure. Standard demographic and surgical data, daily in-hospital opioid consumption, and opioid prescriptions 1 year after surgery were compared. RESULTS: Of 296 OSA patients meeting inclusion criteria, 172 were propensity-matched to non-OSA patients. Demographics were similar between cohorts (OSA: 77 males, mean age=57.69 yr; non-OSA: 67 males, mean age=58.94 yr). OSA patients had lower blood loss (326 mL vs. 399 mL, P =0.014), surgical time (201 vs. 233 min, P <0.001) emergence to extubation time (9.1 vs. 14.2 min, P< 0.001), and recovery room time (119 vs. 140 min, P =0.0.012) compared with non-OSA patients. Fewer OSA patients required nonhome discharge (18 vs. 41, P =0.001) compared with the non-OSA cohort, but no difference in length of stay (90.3 vs. 98.5 h, P =0.204). Daily opioid consumption was lower in the OSA versus the non-OSA cohort from postoperative day 2 (223 vs. 185 morphine milligram equivalents, P =0.017) and maintained each day with lower total consumption (293 vs. 225 morphine milligram equivalents, P =0.003) throughout postoperative day 4. The number of patients with active opioid prescriptions at 1, 3, 6, and 12 months postoperative was statistically fewer in the OSA compared with the non-OSA patients. CONCLUSIONS: OSA for lumbar spinal fusion surgery decreases in-hospital and 1-year postoperative opioid consumption. The minimal use of opioids may also lead to shorter emergence to extubation times, shorter recovery room stays, and fewer discharges to nonhome facilities.