Multicentre investigation on the effect of decompressive surgery on Balance and physical ActiviTy Levels amongst patients with lumbar Spinal stenosis (B-ATLAS): protocol for a prospective cohort study.

INTRODUCTION: Patients with lumbar spinal stenosis may have poor balance, decreased physical function and problems maintaining physical activity levels due to radiculopathy. Decompressive surgery is often indicated if conservative management fails to achieve a satisfactory clinical outcome. While surgical management has proven effective at treating radiculopathy, and patients report increased physical function postoperatively, objective measures of postural control and physical activity remain sparse. This study aims to investigate the effects of decompressive surgery on postural control and activity levels of elderly patients with lumbar spinal stenosis using objective measurements. METHODS AND ANALYSIS: This is a 24-month, multicentre, prospective cohort study. Patients ≥65 years of age with MRI-verified symptomatic lumbar central canal stenosis will be recruited from two separate inclusion centres, and all participants will undergo decompressive surgery. Preoperative data are collected up to 3 months before surgery, with follow-up data collected at 3, 6, 12 and 24 months postoperatively. Postural control measurements are performed using the Wii Balance Board, mini Balance Evaluation Systems Test and Tandem test, and data concerning physical activity levels are collected using ActiGraph wGT3X-BT accelerometers. Patient-reported outcomes regarding quality-of-life and physical function are collected from the EuroQol-5D, 36-Item Short Form Health Survey and Zurich Claudication Questionnaire. Primary outcomes are the change in the sway area of centre of pressure and total activity counts per day from baseline to follow-up at 24 months. A sample size of 80 participants has been calculated. ETHICS AND DISSEMINATION: The study has been approved by the Regional Ethics Committee of Region Zealand (ID EMN-2022-08110) and the Danish Data Protection Agency (ID REG-100-2022). Written informed consent will be required from all participants before enrolment. All results from the study, whether positive, negative or inconclusive, will be published in international peer-reviewed journals and presented at national and international scientific meetings. Study findings will be further disseminated through national patient associations. TRIAL REGISTRATION NUMBERS: NCT06075862 and NCT06057428.

Comparison of Complication Rates Between Transforaminal Interbody Fusion and Anteroposterior Fusion for One- or Two-Level Degenerative Lumbar Spine Surgery: A Propensity Score Matched Analysis.

Introduction Although transforaminal interbody fusion (TLIF) and anterior lumbar interbody fusion (ALIF) combined with posterior fusion (AP) have similar fusion rates, it is unclear if choice of approach has an impact on post-operative complications. Research question Is the incidence of residual leg and/or back pain requiring additional treatment after one- or two-level TLIF and AP similar? Material and methods Adult patients who underwent one- or two-level TLIF or AP for degenerative pathology were identified and matched using age, sex, body mass index (BMI), American Society of Anesthesiologists (ASA), insurance status, smoking status, revision and number of levels fused. The incidence of radicular leg and back pain requiring emergency department visit/readmission or same level surgical intervention was compared between the two groups. Results Of the 319 TLIF and 288 AP cases, 119 cases in each cohort were matched. TLIF patients had shorter operative times (203 min vs 258 min, P<0.001) and hospital stays than the AP patients (3.76 days vs 4.98 days, P<0.001). The incidence of residual leg pain (7 vs 5, P=0.769) and back pain (13 vs 15, P=0.841) was similar between the two groups. Except for constipation, which was more common in the AP group, the incidence of complications was similar between the two groups. Conclusions Patients undergoing one- or two-level TLIF showed shorter operative time and hospital stay compared with those undergoing AP. The incidence of leg radiculopathy and back pain was similar between the two groups. Surgeons should consider these findings as part of the decision-making process regarding which approach to use in patients requiring a lumbar interbody fusion.

Opioid Sparing Anesthesia for Adult Spinal Deformity Surgery Reduces Postoperative Pain, Length of Stay, Opioid Consumption, and Opioid-Related Complications: A Propensity-Matched Analysis.

STUDY DESIGN: This study was a retrospective propensity-matched study of patients receiving opioid sparing anesthesia (OSA) and those who did not receive an opioid sparing anesthesia regimen. OBJECTIVES: To determine whether patients undergoing spine fusion for deformity fared better with an OSA regimen than those not having an OSA regimen. SUMMARY OF BACKGROUND DATA: There has been a tremendous focus on opioid overuse. Accordingly, OSA regimens are being introduced to reduce narcotic use. However, OSA has not been studied in the adult spine deformity population. METHODS: 43 patients undergoing fusion of at least five levels in the thoracolumbar spine received OSA. They were matched to 43 patients who did receive an OSA regimen. We analyzed a number of metrics including blood loss, anesthesia time, post anesthesia care unit (PACU) pain scores, postoperative pain scores, complications, length of stay, and readmissions. RESULTS: The OSA group had significantly lower pain scores both before transfer to (4.6 vs. 7.6, P=0.000) and after transfer from (4.2 vs. 6.2 P=0.002) the PACU. Opioid use was significantly lower in the OSA group (454 vs. 241 MMEs by POD4, P=0.022). Fewer patients required blood transfusion in the OSA (1 vs. 28, P=0.000) group. Fewer patients in the OSA group had constipation and urinary retention (1 vs. 9, P=0.015). There was no difference in discharge home or to a facility. The lengths of hospital (4.33 vs. 6.19, P=0.009) and ICU (0.12 vs. 0.70 days, P=0.009) stay were significantly shorter in the OSA group. CONCLUSION: OSA regimens have numerous benefits in patients undergoing spinal deformity surgery including less opioid use, fewer postoperative complications, and a reduced length of stay.

Predictors of Delayed Clinical Benefit Following Surgical Treatment for Low Grade Spondylolisthesis.

STUDY DESIGN: Retrospective review of prospectively collected data. OBJECTIVE: To investigate what factors predict delayed improvement after surgical treatment of low grade spondylolisthesis. SUMMARY OF BACKGROUND DATA: Lumbar surgery leads to clinical improvement in the majority of patients with low grade spondylolisthesis. Most patients improve rapidly after surgery, but some patients demonstrate a delayed clinical course. METHODS: The Quality and Outcomes Database (QOD) was queried for grade 1 spondylolisthesis patients who underwent surgery who had patient reported outcome measures (PROMs) collected at baseline, 3-, 6- and 12-months, including back and leg pain numeric rating scale (NRS), Oswestry Disability Index (ODI), and EuroQol-5D (EQ-5D). Patients were stratified as "Early responders" reaching MCID at 3 months and maintaining improvement through 12 months and "Delayed responders" not reaching MCID at 3 months but ultimately reaching MCID at 12 months. These two groups were compared with respect to factors which predicted delayed improvement. RESULTS: Of 608 patients enrolled, 436 (72%) met inclusion criteria for this study. Overall, 317 patients (72.7%) reached MCID for ODI at 12 months following surgery. Of these patients, 249 (78.5%) exhibited a rapid clinical improvement trajectory and had achieved ODI MCID threshold by the 3-month postop follow-up. 68 patients (21.4%) showed a delayed trajectory, and had not achieved ODI MCID threshold at 3 months, but did ultimately reach MCID at 12-month follow-up. Factors associated with delayed improvement included impaired preoperative ambulatory status, better baseline back and leg pain scores, and worse 3-month leg pain scores (P<0.01). CONCLUSIONS: The majority of patients undergoing surgery for low grade spondylolisthesis reach ODI MCID threshold rapidly, within the first three months after surgery. Factors associated with a delayed clinical course include impaired preoperative ambulation status, relatively better preoperative back and leg pain, and persistent leg pain at 3 months.

Prospective Analysis of Incisional Morbidity Associated With Anterior Surgical Approaches to the Lumbar Spine.

OBJECTIVE: Anterior approaches to the lumbar spine have been used extensively for various indications but they are also associated with unique complications and have been linked with higher incisional morbidity.This study aimsto evaluate incisional morbidity related to anterior lumbar surgeries and to assess how incisional outcomes correlate with patient and surgery-related factors. METHODS: Patients ≥18 years old and with planned anterior lumbar fusions from L1 to S1 were prospectively enrolled. Follow-up ended at two years, and patients who did not complete the follow-up were excluded. Incision was assessed for general appearance, width, color, cross-hatching, hypertrophy, and pain by using a validated scoring system and a visual analog scale (VAS). Patient and surgery-related factors were analyzed for possible correlations with complications or wound-related parameters. RESULTS: A total of 205 patients with a mean age of 54.4 ± 11.5 were included. Significant improvements were seen in color, hypertrophy, pain, and appearance of the incision. At two years, the mean patient-based VAS for appearance was 8.6 while surgeon-based VAS was 8.8. The total rate of complications was 9%, with no incisional hernia or bulging. No significant relation was found between incision-related parameters and the demographic and surgical variables. CONCLUSION: This study reports acceptable cosmetic results and no chronic pain after anterior lumbar surgery, which is contrary to previous reports. Together with a low total rate of complications, anterior approaches are safe when carefully executed, and have low morbidity.

Spinal cord injury in high-risk complex adult spinal deformity surgery: review of incidence and outcomes from the Scoli-RISK-1 study.

STUDY DESIGN: Clinical case series. OBJECTIVE: To describe the cause, treatment and outcome of 6 cases of perioperative spinal cord injury (SCI) in high-risk adult deformity surgery. SETTING: Adult spinal deformity patients were enrolled in the multi-center Scoli-RISK-1 cohort study. METHODS: A total of 272 patients who underwent complex adult deformity surgery were enrolled in the prospective, multi-center Scoli-RISK-1 cohort study. Clinical follow up data were available up to a maximum of 2 years after index surgery. Cases of perioperative SCI were identified and an extensive case review was performed. RESULTS: Six individuals with SCI were identified from the Scoli-RISK-1 database (2.2%). Two cases occurred intraoperatively and four cases occurred postoperatively. The first case was an incomplete SCI due to a direct intraoperative insult and was treated postoperatively with Riluzole. The second SCI case was caused by a compression injury due to overcorrection of the deformity. Three cases of incomplete SCI occurred; one case of postoperative hematoma, one case of proximal junctional kyphosis (PJK) and one case of adjacent segment disc herniation. All cases of post-operative incomplete SCI were managed with revision decompression and resulted in excellent clinical recovery. One case of incomplete SCI resulted from infection and PJK. The patient's treatment was complicated by a delay in revision and the patient suffered persistent neurological deficits up to six weeks following the onset of SCI. CONCLUSION: Despite the low incidence in high-risk adult deformity surgeries, perioperative SCI can result in devastating consequences. Thus, appropriate postoperative care, follow up and timely management of SCI are essential.

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.

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.

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.

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.

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.

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.

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.

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 percutaneous vertebroplasty (PVP) at the same orthopedic department has changed after the 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 PVP when biopsies were obtained during the procedure. The MRI scanning protocol was changed in this period. METHODS: Retrospective on 427 patients with vertebral compression fracture undergoing PVP from April 28, 2017 to April 28, 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.

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.

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.

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.

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]).