Laminoplasty Versus Laminectomy and Posterior Fusion for Cervical Myelopathy: A Meta-analysis of Radiographic and Clinical Outcomes.

STUDY DESIGN: Meta-analysis. OBJECTIVE: This meta-analysis investigates the outcomes of laminoplasty (LP) and laminectomy with fusion (LF) to guide effective patient selection for these two procedures. BACKGROUND: While LF traditionally offers the ability for excellent posterior decompression, it may alter cervical spine biomechanics and increase the risk of adjacent segment degeneration. LP aims to preserve the natural kinematics of the spine but has not been universally accepted, and may be associated with inadequate decompression, neck pain, and recurrent stenosis. METHODS: PubMed, Cochrane, and Google Scholar (Pages 1-20) were searched up until March 2024. The outcomes studied were surgery-related outcomes (operating room (OR) time, estimated blood loss (EBL), and length of stay (LOS)), adverse events (overall complications, C5 palsy, and reoperations), radiographic outcomes (cervical lordosis (CL), cervical sagittal vertical axis (cSVA), and T1 slope angle (T1SA)), and patient-reported outcome measures (PROMs) (Neck Disability Index (NDI), Visual Analog Scale (VAS) for neck pain, and Japanese Orthopaedic Association (JOA)). RESULTS: Twenty-two studies were included in this meta-analysis, of which 19 were retrospective studies, two were prospective non-randomized studies, and one was a randomized controlled trial. A total of 2,128 patients were included, with 1,025 undergoing LP and 1,103 undergoing LF. LP patients experienced significantly shorter OR time (P=0.009), less EBL (P=0.02), a lower rate of overall complications (P<0.00001) and C5 palsy (P=0.003), a lower T1SA (P=0.02), and a lower NDI (P=0.0004). No significant difference was observed in the remaining outcomes. CONCLUSION: This meta-analysis demonstrates that for cervical myelopathy, LP has the benefits of shorter OR time, less EBL, and reduced incidence of C5 palsy as well as overall complication rate. Given these findings, LP remains an important surgical option with a favorable complication profile in patients with cervical myelopathy, although careful patient selection is still paramount in choosing the right procedure for individual patients.

Revision Strategy for Proximal Junctional Failure: Combined Effect of Proximal Extension and Focal Correction.

STUDY DESIGN: Retrospective review of a prospectively-collected multicenter database. OBJECTIVES: The objective of this study was to determine optimal strategies in terms of focal angular correction and length of proximal extension during revision for PJF. METHODS: 134 patients requiring proximal extension for PJF were analyzed in this study. The correlation between amount of proximal junctional angle (PJA) reduction and recurrence of proximal junctional kyphosis (PJK) and/or PJF was investigated. Following stratification by the degree of PJK correction and the numbers of levels extended proximally, rates of radiographic PJK (PJA >28° & ΔPJA >22°), and recurrent surgery for PJF were reported. RESULTS: Before revision, mean PJA was 27.6° ± 14.6°. Mean number of levels extended was 6.0 ± 3.3. Average PJA reduction was 18.8° ± 18.9°. A correlation between the degree of PJA reduction and rate of recurrent PJK was observed (r = -.222). Recurrent radiographic PJK (0%) and clinical PJF (4.5%) were rare in patients undergoing extension ≥8 levels, regardless of angular correction. Patients with small reductions (<5°) and small extensions (<4 levels) experienced moderate rates of recurrent PJK (19.1%) and PJF (9.5%). Patients with large reductions (>30°) and extensions <8 levels had the highest rate of recurrent PJK (31.8%) and PJF (16.0%). CONCLUSION: While the degree of focal PJK correction must be determined by the treating surgeon based upon clinical goals, recurrent PJK may be minimized by limiting reduction to <30°. If larger PJA correction is required, more extensive proximal fusion constructs may mitigate recurrent PJK/PJF rates.

Perioperative Nutritional, Functional, and Bone Health Optimization in Spine Surgery: A National Investigation of Spine Surgeons' Perceptions and Practices.

INTRODUCTION: While perioperative nutritional, functional, and bone health status optimization in spine surgery is supported with ample evidence, the implementation and surgeon perception regarding such efforts in clinical practice remain largely unexplored. This study sought to assess the current perception of spine surgeons and implementation regarding the nutritional, functional status, and bone health perioperative optimization. METHODS: An anonymous 30-question survey was distributed to orthopaedic spine fellowship and neurosurgery program directors identified through the North American Spine Society and American Association of Neurological Surgeons contact databases. RESULTS: The questionnaire was completed by 51 surgeon survey respondents. Among those, 62% reported no current formal nutritional optimization protocols with 14% not recommending an optimization plan, despite only 10% doubting benefits of nutritional optimization. While 5% of respondents perceived functional status optimization as nonbeneficial, 68% of respondents reported no protocol in place and 46% noted a functional status assessment relying on patient dependency. Among the respondents, 85% routinely ordered DEXA scan if there was suspicion of osteoporosis and 85% usually rescheduled surgery if bone health optimization goals were not achieved while 6% reported being suspicious of benefit from such interventions. CONCLUSION: While most responding spine surgeons believe in the benefit of perioperative nutritional and functional optimization, logistical and patient compliance challenges were noted as critical barriers toward optimization. Understanding surgeon perception and current practices may guide future efforts toward advancement of optimization protocols.

Lumbar Disc Replacement Versus Interbody Fusion: Meta-analysis of Complications and Clinical Outcomes.

Background: Lumbar spinal fusion is a commonly performed operation with relatively high complication and revision surgery rates. Lumbar disc replacement is less commonly performed but may have some benefits over spinal fusion. This meta-analysis aims to compare the outcomes of lumbar disc replacement (LDR) versus interbody fusion (IBF), assessing their comparative safety and effectiveness in treating lumbar DDD. Methods: PubMed, Cochrane, and Google Scholar (pages 1-2) were searched up until February 2024. The studied outcomes included operative room (OR) time, estimated blood loss (EBL), length of hospital stay (LOS), complications, reoperations, Oswestry Disability Index (ODI), back pain, and leg pain. Results: Ten studies were included in this meta-analysis, of which six were randomized controlled trials, three were retrospective studies, and one was a prospective study. A total of 1720 patients were included, with 1034 undergoing LDR and 686 undergoing IBF. No statistically significant differences were observed in OR time, EBL, or LOS between the LDR and IBF groups. The analysis also showed no significant differences in the rates of complications, reoperations, and leg pain between the two groups. However, the LDR group demonstrated a statistically significant reduction in mean back pain (p=0.04) compared to the IBF group. Conclusion: Both LDR and IBF procedures offer similar results in managing CLBP, considering OR time, EBL, LOS, complication rates, reoperations, and leg pain, with slight superiority of back pain improvement in LDR. This study supports the use of both procedures in managing degenerative spinal disease.

Impact of Sacroiliac Belt Utilization on Balance in Patients with Low Back Pain.

Background: Low back pain (LBP) is a common problem which can affect balance and, in turn, increase fall risk. The aim of this investigation was to evaluate the impact of a Sacroiliac Belt (SB) on balance and stability in patients with LBP. Methods: Subjects with LBP and without LBP ("Asymptomatic") were enrolled. Baseline balance was assessed using the Berg Balance Scale. In a counterbalanced crossover design, LBP and Asymptomatic subjects were randomized to one of two groups: 1) start with wearing the SB (Serola Biomechanics, Inc.) followed by not wearing the SB or 2) start without wearing the SB followed by wearing the SB. For subjects in both groups, dynamic balance was then assessed using the Star Excursion Balance Test (SEBT) with each leg planted. Results: Baseline balance was worse in LBP subjects (Berg 51/56) than Asymptomatic subjects (Berg 56/56) (p<0.01). SB significantly improved SEBT performance in LBP subjects regardless of which leg was planted (p<0.01). SB positively impacted Asymptomatic subjects' SEBT performance with the left leg planted (p=0.0002). Conclusion: The Serola Sacroiliac Belt positively impacted dynamic balance for subjects with low back pain. Further research is needed to examine additional interventions and outcomes related to balance in patients with back pain, and to elucidate the mechanisms behind improvements in balance related to sacroiliac belt utilization.

Dual versus Single Attending Surgeon Performance of Spinal Deformity Surgery? A Meta-Analysis.

BACKGROUND: The inclusion of two surgeons in spinal deformity surgery is considered beneficial by some. In fact, select studies indicate advantages such as reduced operation time and blood loss. Another observed decreased patient morbidity with a dual-surgeon approach, attributed to shorter operative times and reduced intra-operative blood losses. Therefore, this meta-analysis will assess the benefits of a having two surgeons compared to one surgeon during spine surgeries. METHODS: PubMed, Cochrane, and Google Scholar (page 1-20) were searched till January 2024. The clinical outcomes evaluated were the incidence of adverse events, the rate of transfusion, reoperation, and surgery-related parameters such as operative room time, length of stay (LOS), and estimated blood loss (EBL). RESULTS: Thirteen studies were included. A greater rate of complications was seen in patients operated upon by one surgeon (OR=0.50; 95% CI: 0.25-0.99, p=0.05). Furthermore, operative room time (MD=-82.73; 95% CI: -111.42- -54.03, p<.001), and LOS (MD=-0.91; 95% CI: -1.12- -0.71, p<.001) were reduced in the dual surgeon scenario. No statistically significant difference was shown in the remaining analyzed outcomes. CONCLUSION: The presence of two surgeons in the OR was shown to reduce complications, operative room time, and LOS. More cost-effectiveness studies are needed in order to substantiate the financial advantages associated with the dual-surgeon approach.

Segmental Sagittal Alignment in Lumbar Spinal Fusion: A Review of Evidence-Based Evaluation of Preoperative Measurement, Surgical Planning, Intraoperative Execution, and Postoperative Evaluation.

BACKGROUND AND OBJECTIVES: Maintaining and restoring global and regional sagittal alignment is a well-established priority that improves patient outcomes in patients with adult spinal deformity. However, the benefit of restoring segmental (level-by-level) alignment in lumbar fusion for degenerative conditions is not widely agreed on. The purpose of this review was to summarize intraoperative techniques to achieve segmental fixation and the impact of segmental lordosis on patient-reported and surgical outcomes. METHODS: In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, PubMed, Embase, Cochrane, and Web of Science databases were queried for the literature reporting lumbar alignment for degenerative lumbar spinal pathology. Reports were assessed for data regarding the impact of intraoperative surgical factors on postoperative segmental sagittal alignment and patient-reported outcome measures. Included studies were further categorized into groups related to patient positioning, fusion and fixation, and interbody device (technique, material, angle, and augmentation). RESULTS: A total of 885 studies were screened, of which 43 met inclusion criteria examining segmental rather than regional or global alignment. Of these, 3 examined patient positioning, 8 examined fusion and fixation, 3 examined case parameters, 26 examined or compared different interbody fusion techniques, 5 examined postoperative patient-reported outcomes, and 3 examined the occurrence of adjacent segment disease. The data support a link between segmental alignment and patient positioning, surgical technique, and adjacent segment disease but have insufficient evidence to support a relationship with patient-reported outcomes, cage subsidence, or pseudoarthrosis. CONCLUSION: This review explores segmental correction's impact on short-segment lumbar fusion outcomes, finding the extent of correction to depend on patient positioning and choice of interbody cage. Notably, inadequate restoration of lumbar lordosis is associated with adjacent segment degeneration. Nevertheless, conclusive evidence linking segmental alignment to patient-reported outcomes, cage subsidence, or pseudoarthrosis remains limited, underscoring the need for future research.

Same-Day Versus Staged Spinal Fusion: A Meta-analysis of Clinical Outcomes.

STUDY DESIGN: Meta-Analysis. OBJECTIVE: This meta-analysis aims to compare same-day versus staged spine surgery, assessing their effects on patient care and healthcare system efficiency. BACKGROUND: In spinal surgery, the debate between whether same-day and staged surgeries are better for patients continues, as the decision may impact patient related outcomes, healthcare resources and overall costs. While some surgeons advocate for staged surgeries citing reduced risks of complications, others proclaim same-day surgeries may minimize costs and length of hospital stays. METHODS: PubMed, Cochrane and Google Scholar (Pages 1-20) were searched up until February 2024. The studied outcomes were operative room (OR) time, estimated blood loss (EBL), length of hospital stay (LOS), overall complications, venous thromboembolism (VTE), death, reoperations and non-home discharge. RESULTS: Sixteen retrospective studies were included in this meta-analysis, representing a total of 2346 patients of which 644 underwent staged spinal fusion surgeries and 1702 same-day surgeries. No statistically significant difference was observed in EBL between staged and same-day surgery groups. However, the staged group exhibited a statistically significant longer OR time (P= 0.05) and LOS (P=0.004). A higher rate of overall complications (P=0.002) and VTE (P=0.0008) was significantly associated with the staged group. No significant differences were found in the rates of death, reoperations, and non-home discharge between the two groups. CONCLUSION: Both staged and same-day spinal fusion surgeries showed comparable rates of death, reoperations and non-home discharges for patients undergoing spinal surgeries. However, given the increased OR time, LOS and complications associated with staged spinal surgeries, this study supports same-day surgeries when possible to minimize the burden on healthcare resources and enhance efficiency.

Cutibacterium acnes in spine surgery: pathophysiology, diagnosis, and treatment.

Cutibacterium acnes (C. acnes) previously named Propionibacterium acnes (P. acnes) has been increasingly recognized by spine surgeons as a cause of indolent post-surgical spinal infection. Patients infected with C. acnes may present with pseudarthrosis or nonspecific back pain. Currently, microbiological tissue cultures remain the gold standard in diagnosing C. acnes infection. Ongoing research into using genetic sequencing as a diagnostic method shows promising results and may be another future way of diagnosis. Optimized prophylaxis involves the use of targeted antibiotics, longer duration of antibiotic prophylaxis, antibacterial-coated spinal implants, and evidence-based sterile surgical techniques all of which decrease contamination. Antibiotics and implant replacement remain the mainstay of treatment, with longer durations of antibiotics proving to be more efficacious. Local guidelines must consider the surge of antimicrobial resistance worldwide when treating C. acnes.

Preoperative Resilience and Improvement in Patient-Reported Outcomes After Lumbar Spinal Fusion.

BACKGROUND: It is incompletely understood how preoperative resilience affects 1-year postoperative outcomes after lumbar spinal fusion. METHODS: Patients undergoing open lumbar spinal fusion at a single-center institution were identified between November 2019 and September 2022. Preoperative resilience was assessed using the Brief Resilience Scale. Demographic data at baseline including age, gender, comorbidities, and body mass index (BMI) were extracted. Patient-reported outcome measures including Oswestry Disability Index, PROMIS (Patient-Reported Outcomes Measurement Information System) Global Physical Health, PROMIS Global Mental Health (GMH), and EuroQol5 scores were collected before the surgery and at 3 months and 1 year postoperatively. Bivariate correlation was conducted between Brief Resilience Scale scores and outcome measures at 3 months and 1 year postoperatively. RESULTS: Ninety-three patients had baseline and 1 year outcome data. Compared with patients with high resilience, patients in the low-resilience group had a higher percentage of females (69.4% vs. 43.9%; P = 0.02), a higher BMI (32.7 vs. 30.1; P = 0.03), and lower preoperative Global Physical Health (35.8 vs. 38.9; P = 0.045), GMH (42.2 vs. 49.2; P < 0.001), and EuroQol scores (0.56 vs. 0.61; P = 0.01). At 3 months postoperatively, resilience was moderately correlated with GMH (r = 0.39) and EuroQol (r = 0.32). Similarly, at 1 year postoperatively, resilience was moderately correlated with GMH (r = 0.33) and EuroQol (r = 0.34). Comparable results were seen in multivariable regression analysis controlling for age, gender, number of levels fused, BMI, Charlson Comorbidity Index, procedure, anxiety/depression, and complications. CONCLUSIONS: Low preoperative resilience can negatively affect patient-reported outcomes 1 year after lumbar spinal fusion. Resiliency is a potentially modifiable risk factor, and surgeons should consider targeted interventions for at-risk patient groups.

Impact of Self-Reported Loss of Balance and Gait Disturbance on Outcomes following Adult Spinal Deformity Surgery.

Background: The objective of this study was to evaluate if imbalance influences complication rates, radiological outcomes, and patient-reported outcomes (PROMs) following adult spinal deformity (ASD) surgery. Methods: ASD patients with baseline and 2-year radiographic and PROMs were included. Patients were grouped according to whether they answered yes or no to a recent history of pre-operative loss of balance. The groups were propensity-matched by age, pelvic incidence-lumbar lordosis (PI-LL), and surgical invasiveness score. Results: In total, 212 patients were examined (106 in each group). Patients with gait imbalance had worse baseline PROM measures, including Oswestry disability index (45.2 vs. 36.6), SF-36 mental component score (44 vs. 51.8), and SF-36 physical component score (p < 0.001 for all). After 2 years, patients with gait imbalance had less pelvic tilt correction (-1.2 vs. -3.6°, p = 0.039) for a comparable PI-LL correction (-11.9 vs. -15.1°, p = 0.144). Gait imbalance patients had higher rates of radiographic proximal junctional kyphosis (PJK) (26.4% vs. 14.2%) and implant-related complications (47.2% vs. 34.0%). After controlling for age, baseline sagittal parameters, PI-LL correction, and comorbidities, patients with imbalance had 2.2-times-increased odds of PJK after 2 years. Conclusions: Patients with a self-reported loss of balance/unsteady gait have significantly worse PROMs and higher risk of PJK.

The impact of asymptomatic human immunodeficiency virus (HIV)-positive disease status on inpatient complications following total joint arthroplasty: a propensity score-matched analysis.

PURPOSE: The number of patients with asymptomatic human immunodeficiency virus (AHIV) is increasing as the efficacy of antiretroviral therapy improves. While there is research on operative risks associated with having HIV, there is a lack of literature describing the impact of well-controlled HIV on postoperative complications. This study seeks to elucidate the impact of AHIV on postoperative outcomes after total hip (THA) and knee (TKA) arthroplasty. METHODS: The Nationwide Inpatient Sample was retrospectively reviewed for patients undergoing TKA and THA from 2005 to 2013. Subjects were subdivided into those with AHIV and those without HIV (non-HIV). Patient demographics, hospital-related parameters, and postoperative complications were all collected. One-to-one propensity score-matching, Chi-square analysis, and multivariate logistical regressions were performed to compare both cohorts. RESULTS: There were no significant differences between AHIV and non-HIV patients undergoing TKA or THA in terms of sex, age, insurance status, or total costs (all, p ≥ 0.081). AHIV patients had longer lengths of stay (4.0 days) than non-HIV patients after both TKA (3.3 days) and THA (3.1 days) (p ≤ 0.011). Both TKA groups had similar postoperative complication rates (p > 0.081). AHIV patients undergoing THA exhibited an increased rate of overall surgical complications compared non-HIV patients (0 vs. 4.5%, p = 0.043). AHIV was not associated with increased complications following both procedures. CONCLUSION: Despite lengthier hospital stays among AHIV patients, baseline AHIV was not associated with adverse outcomes following TKA and THA. This adds to the literature and warrants further research into the impact of asymptomatic, well-controlled HIV infection on postoperative outcomes following total joint arthroplasty.

Management of Thoracolumbar Vertebral Fractures and Dislocations in Patients with Ankylosing Conditions of the Spine.

Ankylosing spondylitis (AS) and diffuse idiopathic skeletal hyperostosis (DISH) are bone-forming spinal conditions which inherently increase spine rigidity and place patients at a higher risk for thoracolumbar fractures. Due to the long lever-arm associated with their pathology, these fractures are frequently unstable and may significantly displace leading to catastrophic neurologic consequences. Operative and non-operative management are considerations in these fractures. However conservative measures including immobilization and bracing are typically reserved for non-displaced or incomplete fractures, or in patients for whom surgery poses a high risk. Thus, first line treatment is often surgery which has historically been an open posterior spinal fusion. Recent techniques such as minimally invasive surgery (MIS) and robotic surgery have shown promising lower complication rates as compared to open techniques, however these methods need to be further validated.

Variability in expenses related to spine oncology care: comparison of payer-negotiated rates at National Cancer Institute-Designated Cancer Centers.

BACKGROUND: As of 2021, the Centers for Medicare and Medicaid Services (CMS) requires all hospitals to publish their commercially negotiated prices. To our knowledge, price variation of spine oncology diagnosis and treatments has not been previously investigated. PURPOSE: The aim of this study is to characterize the availability and variation of prices for spinal oncology services among National Cancer Institute-Designated Cancer Centers (NCI-DCC). STUDY DESIGN: Cross-sectional analysis. METHODS: Cancer centers were identified; those that did not provide patient care or participate in Medicare's Inpatient Prospective System were excluded. A cross-sectional analysis was conducted to gather commercially negotiated prices by searching online for "[center name] price transparency OR machine-readable file OR chargemaster." Data obtained was queried using 44 current procedural terminology (CPT) codes for imaging, procedures, and surgeries relevant to spine oncology. Comparison of prices was achieved by normalizing the median price for each service at each center to the estimated 2022 Medicare reimbursement for the center's Medicare Administrator Contractor. The ratios between the lowest and highest median commercial negotiated price within a center and across all centers were defined as "within-center ratio" and "across-center ratio" respectively. RESULTS: In total, 49 centers disclosed commercial payer-negotiated rates. Mean rate (±SD) for cervical corpectomy was $9,134 (±$10,034), thoracic laminectomy for neoplasm excision was $5,382 (±$5502), superficial bone biopsy was $1,853 (±$1,717), and single-photon emission computerized tomography (SPECT) was $813 (±$232). Within-center ratios ranged from 5.0 (SPECT scan) to 17.8 (radiofrequency bone ablation). Across-center ratios (for codes with > 10 centers reporting) ranged from 9.0 (corpectomy, thoracic, lateral extra-cavitary) to 418.7 (anterior approach cervical corpectomy). CONCLUSIONS: Price transparency for spinal oncology remains elusive despite recent CMS regulatory oversight, with marked heterogeneity in the quality of published rates complicating patients' ability to "shop" for care. Additionally, there continues to be significant variation in commercial rates for spine oncology diagnosis and treatment. CLINICAL SIGNIFICANCE: Despite regulation by CMS, prices for spinal oncology services are not uniformly available to patients and vary between NCI-DCC. The findings of this manuscript present potential barriers for patients to compare and obtain affordable care.

Management of traumatic spinal cord injury: A current concepts review of contemporary and future treatment.

Spinal Cord Injury (SCI) is a condition leading to inflammation, edema, and dysfunction of the spinal cord, most commonly due to trauma, tumor, infection, or vascular disturbance. Symptoms include sensory and motor loss starting at the level of injury; the extent of damage depends on injury severity as detailed in the ASIA score. In the acute setting, maintaining mean arterial pressure (MAP) higher than 85 mmHg for up to 7 days following injury is preferred; although caution must be exercised when using vasopressors such as phenylephrine due to serious side effects such as pulmonary edema and death. Decompression surgery (DS) may theoretically relieve edema and reduce intraspinal pressure, although timing of surgery remains a matter of debate. Methylprednisolone (MP) is currently used due to its ability to reduce inflammation but more recent studies question its clinical benefits, especially with inconsistency in recommending it nationally and internationally. The choice of MP is further complicated by conflicting evidence for optimal timing to initiate treatment, and by the reported observation that higher doses are correlated with increased risk of complications. Thyrotropin-releasing hormone may be beneficial in less severe injuries. Finally, this review discusses many options currently being researched and have shown promising pre-clinical results.

Comparison of multilevel low-grade techniques versus three-column osteotomies in adult spinal deformity surgery: does harmonious correction matter?

OBJECTIVE: Recent debate has arisen between whether to use a three-column osteotomy (3CO) or multilevel low-grade (MLG) techniques to treat severe sagittal malalignment in adult spinal deformity (ASD) surgery. The goal of this study was to compare the outcomes of 3CO and MLG techniques performed in corrective surgeries for ASD. METHODS: ASD patients who had a baseline PI-LL > 30° and 2-year follow-up data were included. Patients underwent either 3CO or MLG (thoracolumbar posterior column osteotomies at ≥ 3 levels or anterior lumbar interbody fusion at ≥ 3 levels with no 3CO). The segmental utility ratio was used to assess relative segmental correction (segmental correction divided by overall correction in lordosis divided by the number of thoracolumbar interventions [interbody fusion, thoracolumbar posterior column osteotomies, and 3CO]). The paired t-test was used to assess lordotic distribution by differences in lordosis between adjacent lumbar disc spaces (e.g., L1-2 to L2-3). Multivariate analysis, controlling for age, sex, BMI, osteoporosis, baseline pelvic incidence, and T1 pelvic angle, was used to evaluate the complication rates and radiographic and patient-reported outcomes between the groups. RESULTS: A total of 93 patients were included, 53% of whom underwent MLG and 47% of whom underwent 3CO. The MLG group had a lower BMI (p < 0.05). MLG patients received fewer previous fusions than 3CO patients (31% vs 80%, p < 0.001). MLG patients had 24% less blood loss but a 22% longer operative time (565 vs 419 minutes, p = 0.008). Using adjusted analysis, the 3CO group had greater segmental and relative correction at each level (segmental utility ratio mean 69% for 3CO vs 23% for MLG, p < 0.001). However, the 3CO group had lordotic differences between two adjacent lumbar disc pairs (range -0.5° to 9.0°, p = 0.009), while MLG was more harmonious (range 2.2°-6.5°, p > 0.4). MLG patients were more likely to undergo realignment to age-adjusted standards (OR 5.6, 95% CI 1.2-46.4; p = 0.033). MLG patients were less likely to develop neurological complications or undergo reoperation (OR 0.4, 95% CI 0.1-0.9; p = 0.041). Adjusted analysis revealed that MLG patients more often met a substantial clinical benefit in the Oswestry Disability Index score (OR 5.3, 95% CI 1.1-26.8; p = 0.043). CONCLUSIONS: MLG techniques showed better utility in lumbar distribution and age-adjusted global correction while minimizing neurological complications and reoperation rates by 2 years postoperatively. In selected instances, these techniques may offer the spine deformity surgeon a safer alternative when correcting severe adult spinal deformity.

Development of a modified frailty index for adult spinal deformities independent of functional changes following surgical correction: a true baseline risk assessment tool.

PURPOSE: To develop a simplified, modified frailty index for adult spinal deformity (ASD) patients dependent on objective clinical factors. METHODS: ASD patients with baseline (BL) and 2-year (2Y) follow-up were included. Factors with the largest R2 value derived from multivariate forward stepwise regression were including in the modified ASD-FI (clin-ASD-FI). Factors included in the clin-ASD-FI were regressed against mortality, extended length of hospital stay (LOS, > 8 days), revisions, major complications and weights for the clin-ASD-FI were calculated via Beta/Sullivan. Total clin-ASD-FI score was created with a score from 0 to 1. Linear regression correlated clin-ASD-FI with ASD-FI scores and published cutoffs for the ASD-FI were used to create the new frailty cutoffs: not frail (NF: < 0.11), frail (F: 0.11-0.21) and severely frail (SF: > 0.21). Binary logistic regression assessed odds of complication or reop for frail patients. RESULTS: Five hundred thirty-one ASD patients (59.5 yrs, 79.5% F) were included. The final model had a R2 of 0.681, and significant factors were: < 18.5 or > 30 BMI (weight: 0.0625 out of 1), cardiac disease (0.125), disability employment status (0.3125), diabetes mellitus (0.0625), hypertension (0.0625), osteoporosis (0.125), blood clot (0.1875), and bowel incontinence (0.0625). These factors calculated the score from 0 to 1, with a mean cohort score of 0.13 ± 0.14. Breakdown by clin-ASD-FI score: 51.8% NF, 28.1% F, 20.2% SF. Increasing frailty severity was associated with longer LOS (NF: 7.0, F: 8.3, SF: 9.2 days; P < 0.001). Frailty independently predicted occurrence of any complication (OR: 9.357 [2.20-39.76], P = 0.002) and reop (OR: 2.79 [0.662-11.72], P = 0.162). CONCLUSIONS: Utilizing an existing ASD frailty index, we proposed a modified version eliminating the patient-reported components. This index is a true assessment of physiologic status, and represents a superior risk factor assessment compared to other tools for both primary and revision spinal deformity surgery as a result of its immutability with surgery, lack of subjectivity, and ease of use.

Impact of Hip and Knee Osteoarthritis on Full Body Sagittal Alignment and Compensation for Sagittal Spinal Deformity.

STUDY DESIGN: Retrospective review of prospectively collected data. OBJECTIVE: To investigate the effect of lower extremity osteoarthritis on sagittal alignment and compensatory mechanisms in adult spinal deformity (ASD). BACKGROUND: Spine, hip, and knee pathologies often overlap in ASD patients. Limited data exists on how lower extremity osteoarthritis impacts sagittal alignment and compensatory mechanisms in ASD. PATIENTS AND METHODS: In total, 527 preoperative ASD patients with full body radiographs were included. Patients were grouped by Kellgren-Lawrence grade of bilateral hips and knees and stratified by quartile of T1-Pelvic Angle (T1PA) severity into low-, mid-, high-, and severe-T1PA. Full-body alignment and compensation were compared across quartiles. Regression analysis examined the incremental impact of hip and knee osteoarthritis severity on compensation. RESULTS: The mean T1PA for low-, mid-, high-, and severe-T1PA groups was 7.3°, 19.5°, 27.8°, and 41.6°, respectively. Mid-T1PA patients with severe hip osteoarthritis had an increased sagittal vertical axis and global sagittal alignment ( P <0.001). Increasing hip osteoarthritis severity resulted in decreased pelvic tilt ( P =0.001) and sacrofemoral angle ( P <0.001), but increased knee flexion ( P =0.012). Regression analysis revealed that with increasing T1PA, pelvic tilt correlated inversely with hip osteoarthritis and positively with knee osteoarthritis ( r2 =0.812). Hip osteoarthritis decreased compensation through sacrofemoral angle (ß-coefficient=-0.206). Knee and hip osteoarthritis contributed to greater knee flexion (ß-coefficients=0.215, 0.101; respectively). For pelvic shift, only hip osteoarthritis significantly contributed to the model (ß-coefficient=0.100). CONCLUSIONS: For the same magnitude of spinal deformity, increased hip osteoarthritis severity was associated with worse truncal and full body alignment with posterior translation of the pelvis. Patients with severe hip and knee osteoarthritis exhibited decreased hip extension and pelvic tilt but increased knee flexion. This examines sagittal alignment and compensation in ASD patients with hip and knee arthritis and may help delineate whether hip and knee flexion is due to spinal deformity compensation or lower extremity osteoarthritis.

Assessing the Accuracy and Reliability of AI-Generated Responses to Patient Questions Regarding Spine Surgery.

BACKGROUND: In today's digital age, patients increasingly rely on online search engines for medical information. The integration of large language models such as GPT-4 into search engines such as Bing raises concerns over the potential transmission of misinformation when patients search for information online regarding spine surgery. METHODS: SearchResponse.io, a database that archives People Also Ask (PAA) data from Google, was utilized to determine the most popular patient questions regarding 4 specific spine surgery topics: anterior cervical discectomy and fusion, lumbar fusion, laminectomy, and spinal deformity. Bing's responses to these questions, along with the cited sources, were recorded for analysis. Two fellowship-trained spine surgeons assessed the accuracy of the answers on a 6-point scale and the completeness of the answers on a 3-point scale. Inaccurate answers were re-queried 2 weeks later. Cited sources were categorized and evaluated against Journal of the American Medical Association (JAMA) benchmark criteria. Interrater reliability was measured with use of the kappa statistic. A linear regression analysis was utilized to explore the relationship between answer accuracy and the type of source, number of sources, and mean JAMA benchmark score. RESULTS: Bing's responses to 71 PAA questions were analyzed. The average completeness score was 2.03 (standard deviation [SD], 0.36), and the average accuracy score was 4.49 (SD, 1.10). Among the question topics, spinal deformity had the lowest mean completeness score. Re-querying the questions that initially had answers with low accuracy scores resulted in responses with improved accuracy. Among the cited sources, commercial sources were the most prevalent. The JAMA benchmark score across all sources averaged 2.63. Government sources had the highest mean benchmark score (3.30), whereas social media had the lowest (1.75). CONCLUSIONS: Bing's answers were generally accurate and adequately complete, with incorrect responses rectified upon re-querying. The plurality of information was sourced from commercial websites. The type of source, number of sources, and mean JAMA benchmark score were not significantly correlated with answer accuracy. These findings underscore the importance of ongoing evaluation and improvement of large language models to ensure reliable and informative results for patients seeking information regarding spine surgery online amid the integration of these models in the search experience.