Epidemiology of Lumbar Spine Fractures: Twenty-Year Assessment of Nationwide Emergency Department Visit Data.

BACKGROUND: Lumbar spine fractures are common injuries associated with substantial morbidity for patients and socioeconomic burden. This study sought to epidemiologically analyze lumbar spine fractures by mechanism of injury and identify temporal trends in patient demographics and disposition, which few studies have previously evaluated. MATERIALS AND METHODS: A retrospective analysis was done of the US National Electronic Injury Surveillance System (NEISS) database between 2003 and 2022. The sample contained all patients 2 to 101 years old with product-related lumbar fractures presenting to participating institutions' emergency departments. A total of 15,196 unweighted injuries (642,979 weighted injuries) were recorded. RESULTS: Overall, there was a 20-year incidence rate of 10.14 cases per 100,000 person-years with a 2-fold increase in fracture incidence. Females were more prone to lumbar fracture than males (P=.032). Injuries primarily stemmed from a fall (76.6%). The incidence of lumbar fracture increased most significantly in older patients, with patients 80 years and older showing the greatest annual increase (ß=8.771, R2=0.7439, P<.001) and patients 60 to 69 years showing the greatest percent increase with a 3.24-fold increase in incidence. Most (58.9%) of the fractures occurred at home. Females were more often injured at home compared with males (P<.001), who more often sustained lumbar fractures during recreational or athletic activity (P<.001). All patients older than 40 years showed at least a doubling in incidence rate of lumbar fracture between 2003 and 2022. CONCLUSION: These data demonstrate the pressing need to address poor bone health in the aging population, shown here to have an increasing fracture burden. [Orthopedics. 202x;4x(x):xx-xx.].

Intraoperative fluid management in adult spinal deformity surgery: variation analysis and association with outcomes.

PURPOSE: To evaluate the variability in intraoperative fluid management during adult spinal deformity (ASD) surgery, and analyze the association with complications, intensive care unit (ICU) requirement, and length of hospital stay (LOS). METHODS: Multicenter comparative cohort study. Patients ≥ 18 years old and with ASD were included. Intraoperative intravenous (IV) fluid data were collected including: crystalloids, colloids, crystalloid/colloid ratio (C/C), total IV fluid (tIVF, ml), normalized total IV fluid (nIVF, ml/kg/h), input/output ratio (IOR), input-output difference (IOD), and normalized input-output difference (nIOD, ml/kg/h). Data from different centers were compared for variability analysis, and fluid parameters were analyzed for possible associations with the outcomes. RESULTS: Seven hundred ninety-eight patients with a median age of 65.2 were included. Among different surgical centers, tIVF, nIVF, and C/C showed significant variation (p < 0.001 for each) with differences of 4.8-fold, 3.7-fold, and 4.9-fold, respectively. Two hundred ninety-two (36.6%) patients experienced at least one in-hospital complication, and ninety-two (11.5%) were IV fluid related. Univariate analysis showed significant relations for: LOS and tIVF (ρ = 0.221, p < 0.001), IOD (ρ = 0.115, p = 0.001) and IOR (ρ = -0.138, p < 0.001); IV fluid-related complications and tIVF (p = 0.049); ICU stay and tIVF, nIVF, IOD and nIOD (p < 0.001 each); extended ICU stay and tIVF (p < 0.001), nIVF (p = 0.010) and IOD (p < 0.001). Multivariate analysis controlling for confounders showed significant relations for: LOS and tIVF (p < 0.001) and nIVF (p = 0.003); ICU stay and IOR (p = 0.002), extended ICU stay and tIVF (p = 0.004). CONCLUSION: Significant variability and lack of standardization in intraoperative IV fluid management exists between different surgical centers. Excessive fluid administration was found to be correlated with negative outcomes. LEVEL OF EVIDENCE: III.

Alignment in motion: Fall risk in spine patients and the effect of vision, support surface, and adaptation on the cone of economy.

Background: Several assessment tools have been developed to estimate a patient's likelihood risk of falling. None of these measures estimate the contributions of the visual, vestibular, and somatosensory systems to fall risk, especially in patients with degenerative lumbar spine disease. Methods: Degenerative lumbar spine patients with radiculopathy (LD) and healthy subjects who were 35-70 years old without spine complaints were recruited. Patient reported outcome measures (PROMs) were collected prior to testing. Fall risk assessment was completed using Computer Dynamic Posturography (CDP), a computer-controlled balance machine that allows cone of economy (CoE) and cone of pressure (CoP) measurements. All patients completed Sensory Organization Tests (SOT) which include normal and perturbed stability, both with and without visual cues. Results: In total, 43 spine patients and 12 healthy controls were included, with mean age 57.8 years, 39.5% females, and mean BMI of 29.3 kg/m2. Nearly all CoE and most CoP dimensions were found to be larger in LD patients compared to controls across nearly all subtests (p<.05), with the largest dimensions generally observed in the surrounding and support sway testing condition. In LD patients, ODI and PROMIS Pain Interference were negatively correlated with CoE and CoP measurements (p<.05). Conclusions: In this prospective study, body sway was assessed as a function of CoE and CoP using the CDP system and was found to be elevated in spine patients, especially when they experienced increasing levels of visual and vestibular stimulation. The ability to identify the primary drivers of balance disorders is essential in spine patients and may be helpful in the development of a patient-specific treatment plan, which may in the future aid with fall-prevention initiatives.

Impact of Segmental Lordosis Restoration During Degenerative Spinal Fusion on Two-Year Adjacent Segment Disease and Revision Rates.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: Assess the impact of inadequate correction of L4-S1 lordosis during transforaminal lumber interbody fusion (TLIF) on adjacent segment disease and revision rates. BACKGROUND: Restoring alignment is an important consideration in spinal fusions. Failure to correct to level-specific alignment goals could promote the development of adjacent segment disease. As such, it is crucial to investigate the role of sagittal segmental alignment on clinical outcomes following short segment lumbar fusion. METHODS: Patients who underwent 1- to 3-level transforaminal lumbar interbody fusion (TLIF) and had two-year outcomes data were included in this retrospective cohort study. Segmental lumbar lordosis was assessed in all patients with L3-L4, L4-L5, and L5-S1 constructs. Demographics, radiographic spinopelvic alignment, and complications were compared in a sub-group of patients fused at L4-S1 with adequate (i.e., within 35-45°) and inadequate (i.e., <35°) L4-S1 lordosis. RESULTS: Among the 168 included patients, mean age was 61.7 years, 56.0% were female, and mean follow-up was 32.3 months. Segmental lumbar lordosis did not change significantly after TLIF of L3-L4, L4-L5, or L5-S1 (P>0.05). Two-year postoperatively, 32.7% developed adjacent segment disease and 19.6% underwent revisions. After stratification by adequate (N=15) or inadequate (N=54) restoration of L4-S1 lordosis following initial TLIF surgery, adequately-restored patients had higher preoperative L4-S1 lordosis (Adequately-Restored=39.3° vs Inadequately-Restored=29.5°, P<0.001) and lower two-year postoperative adjacent segment disease (6.7% vs. 33.3%, P=0.032) and revision (5.7% vs. 25.9%, P=0.l33) rates. Adjacent segment disease patients had higher implant-related complications (Adjacent Segment Disease=36.8% vs No Adjacent Segment Disease=8.0%, P=0.008) and subsequent revisions (61.1% vs. 8.7%, P<0.001). CONCLUSIONS: Adjacent segment disease and revisions after degenerative lumbar spinal fusion are common. In this cohort, suboptimal restoration of L4-S1 lordosis was associated with higher rates of adjacent segment disease and subsequent revisions, thus highlighting the importance of restoring sagittal alignment in degenerative spine surgery. LEVEL OF EVIDENCE: III.

Large Language Model Prompting Techniques for Advancement in Clinical Medicine.

Large Language Models (LLMs have the potential to revolutionize clinical medicine by enhancing healthcare access, diagnosis, surgical planning, and education. However, their utilization requires careful, prompt engineering to mitigate challenges like hallucinations and biases. Proper utilization of LLMs involves understanding foundational concepts such as tokenization, embeddings, and attention mechanisms, alongside strategic prompting techniques to ensure accurate outputs. For innovative healthcare solutions, it is essential to maintain ongoing collaboration between AI technology and medical professionals. Ethical considerations, including data security and bias mitigation, are critical to their application. By leveraging LLMs as supplementary resources in research and education, we can enhance learning and support knowledge-based inquiries, ultimately advancing the quality and accessibility of medical care. Continued research and development are necessary to fully realize the potential of LLMs in transforming healthcare.

Spinal deformity surgery in Scheuermann's kyphosis versus adolescent idiopathic scoliosis: meta-analysis of complications and clinical outcomes.

BACKGROUND: Surgical management of adolescent idiopathic scoliosis (AIS) and Scheuermann's kyphosis (SK) may be associated with several complications including extended length of stay and unplanned reoperations. Several studies have previously compared postoperative complications and functional outcomes for AIS and SK patients with mixed results. However, a meta-analysis compiling the literature on this topic is lacking. METHODS: Following the PRISMA guidelines, PubMed, Cochrane, and Google Scholar (pages 1-20) were accessed and explored until April 2024. The extracted data consisted of complications (overall and surgical-site infections [SSI]), readmissions, reoperations, and Scoliosis Research Society-22 (SRS-22) score. Mean differences (MD) with 95% CI were used for continuous data and odds ratio (OR) was utilized for dichotomous data were calculated across studies. RESULTS: Seven retrospective articles were included in the meta-analysis, including 4866 patients, with 399 in the SK group and 4467 in the AIS group. SK patients were found to have statistically significantly higher rates of overall complications (OR = 5.41; 95% CI 3.69-7.93, p < .001), SSI (OR = 11.30; 95% CI 6.14-20.82, p < .001), readmissions (OR = 2.81; 95% CI 1.21-6.53, p = 0.02), and reoperations (OR = 7.40; 95% CI 4.76-11.51, p < .001) than AIS patients. However, they had similar SRS-22 scores postoperatively (MD = -0.06; 95% CI -0.16 to 0.04, p = 0.26) despite the SK group having lower SRS-22 scores preoperatively (MD = -0.30; 95% CI -0.42 to -0.18, p < .001). CONCLUSION: In this meta-analysis of studies comparing spinal deformity surgery outcomes in AIS and SK patients, SK was associated with more complications, readmissions, and reoperations. SK did have equivalent SRS-22 scores postoperatively to AIS patients, highlighting the benefit of surgical treatment despite higher complication rates. This data may help inform healthcare institutions, payors, and quality monitoring organizations who examine outcomes of pediatric and adult spinal deformity surgery.

The Importance of Alignment in the Management of Thoracolumbar Trauma.

Spinal injuries occur in 3% of all trauma patients, most commonly in males, and often due to high-velocity impact followed by abrupt deceleration. The most affected region following spinal trauma is the thoracolumbar junction due to the anterior center of gravity at T12-L1 vertebral level and the relatively stiff thoracic spine uniting with the mobile lumbar spine. Many classifications exist to guide the choice of operative versus non-operative management of traumatic injuries at this site. However, the current classifications do not consider the segmental alignment of the spine - an aspect which has been shown to improve quality of life in non-traumatic post-operative spinal patients. Ignoring this aspect of thoracolumbar management often contributes to the development of post-traumatic malalignment and other complications. This review recommends that a new or modified classification system accounts for sagittal segmental alignment factors, including the injured vertebra's level, the number of affected adjacent levels, imaging techniques with better specificity and sensitivity, and assessment for osteoporosis. Case studies are included to demonstrate the importance of segmental sagittal alignment and the vertebral level on patient outcomes.

L5-S1 Transforaminal Lumbar Interbody Fusion (TLIF) Is Associated with Increased Revisions Compared to L4-L5 TLIF at Two Years.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: Compare outcomes in patients undergoing one-level transforaminal lumbar interbody fusion (TLIF) at L4-S1. BACKGROUND: TLIF is frequently performed at L4-S1 to treat degenerative lumbar pathologies. However, the native alignment and biomechanics differ across L4-L5 and L5-S1, and there is limited data regarding comparative radiographic outcomes. METHODS: Patients who underwent one-level TLIF at L4-L5 or L5-S1 at a single academic institution were identified. Baseline demographics, procedural characteristics, change in postoperative spinopelvic alignment and patient-reported outcome measures (PROMs), and two-year postoperative surgical complications were compared. Multivariate regression analyses, accounting for age, gender, Charlson Comorbidity Index (CCI), and body mass index (BMI), were also performed. RESULTS: Across the 175 included patients, 125 had L4-L5 TLIF and 50 had L5-S1 TLIF. The mean age was 57.8 years, 56.6% were female, mean CCI was 0.9, and mean follow-up was 26.7 months. In the hospital, the two cohorts were not statistically different with regards to EBL and LOS. Two years postoperatively, multivariate linear regression analyses revealed that L5-S1 TLIF achieved 6.0° higher correction in L4-S1 lordosis ( P =0.012) than L4-L5 TLIF. At the same time, however, L5-S1 TLIF patients experienced significantly higher rates of pseudoarthrosis (8.0% vs 1.6%, P =0.036) and subsequent spine surgery (18.0% vs. 7.2%, P =0.034), specifically for pseudoarthrosis (6.0% vs. 0.0%, P =0.006), with this cohort having 8.7 times higher odds of subsequent spine surgery for pseudoarthrosis ( P =0.015) than L4-L5 TLIF patients on multivariate logistic analyses. PROMs, on the other hand, were not different across the two cohorts. CONCLUSIONS: Although L5-S1 TLIF yielded good radiographic correction, it was associated with higher rates of subsequent spine surgery for pseudoarthrosis compared to L4-L5 TLIF. These findings may be related to differences in native segmental alignment and biomechanics across the L4-L5 and L5-S1 motion segments and are important to consider during surgical planning. LEVEL OF EVIDENCE: IV.

Postoperative Delirium Following Posterior Lumbar Spinal Fusion: Epidemiology, Risk Factors, and Associated Complications.

BACKGROUND: Postoperative delirium (POD) is frequently reported in the elderly after major surgery. Several risk factors have been identified, including age, surgical complexity, and comorbidities. METHODS: Posterior lumbar fusion patients were identified using PearlDiver and filtered into two cohorts based on presence or absence of POD within 7 days of surgery. Epidemiological analyses were performed to examine trends in POD by age and year. Comparative analyses were performed on patient demographics and baseline cognitive status. After matching by age, sex, and comorbidities, electrolyte disturbances and 90-day postoperative complications were analyzed. RESULTS: Among 476,482 no POD and 2,591 POD patients, mean age was 60.90 years, 57.6% were female, and mean CCI was 1.78. POD patients frequently had baseline cognitive impairment (p<0.001). Incidence of POD decreased from 0.7% in 2010 to 0.4% in 2022 (p<0.001) and increased with increasing patient age (p<0.001). POD patients had higher length of stay (12 vs 6 days, p<0.001) and 90-day costs ($20,605 vs $17,849, p<0.001). After matching, POD patients had higher hypernatremia (5.8% vs 3.5%, p=0.001) and hypocalcemia (5.0% vs 3.5%, p=0.026). POD patients had higher 90-day postoperative complications (p<0.05) than no POD patients. CONCLUSION: Nearly 0.5% of patients who underwent posterior spinal fusion between 2010-2022 developed delirium, although incidence rates have decreased over time. POD was common in elderly patients with electrolyte disturbances who underwent multi-level fusions. Patients suffering from POD had higher rates of 90-day postoperative complications. Ongoing efforts to deliver interventions to mitigate the consequences of POD among spine surgery patients are warranted.

Impact of Prior Cervical Fusion on Patients Undergoing Thoracolumbar Deformity Correction.

STUDY DESIGN: Retrospective analysis of prospectively collected data. OBJECTIVE: Evaluate the impact of prior cervical constructs on upper instrumented vertebrae (UIV) selection and postoperative outcomes among patients undergoing thoracolumbar deformity correction. BACKGROUND: Surgical planning for adult spinal deformity (ASD) patients involves consideration of spinal alignment and existing fusion constructs. METHODS: ASD patients with (ANTERIOR or POSTERIOR) and without (NONE) prior cervical fusion who underwent thoracolumbar fusion were included. Demographics, radiographic alignment, patient-reported outcome measures (PROMs), and complications were compared. Univariate and multivariate analyses were performed on POSTERIOR patients to identify parameters predictive of UIV choice and to evaluate postoperative outcomes impacted by UIV selection. RESULTS: Among 542 patients, with 446 NONE, 72 ANTERIOR, and 24 POSTERIOR patients, mean age was 64.4 years and 432 (80%) were female. Cervical fusion patients had worse preoperative cervical and lumbosacral deformity, and PROMs (P<0.05). In the POSTERIOR cohort, preoperative LIV was frequently below the cervicothoracic junction (54%) and uncommonly (13%) connected to the thoracolumbar UIV. Multivariate analyses revealed that higher preoperative cervical SVA (coeff=-0.22, 95%CI=-0.43--0.01, P=0.038) and C2SPi (coeff=-0.72, 95%CI=-1.36--0.07, P=0.031), and lower preoperative thoracic kyphosis (coeff=0.14, 95%CI=0.01-0.28, P=0.040) and thoracolumbar lordosis (coeff=0.22, 95%CI=0.10-0.33, P=0.001) were predictive of cranial UIV. Two-year postoperatively, cervical patients continued to have worse cervical deformity and PROMs (P<0.05) but had comparable postoperative complications. Choice of thoracolumbar UIV below or above T6, as well as the number of unfused levels between constructs, did not affect patient outcomes. CONCLUSIONS: Among patients who underwent thoracolumbar deformity correction, prior cervical fusion was associated with more severe spinopelvic deformity and PROMs preoperatively. The choice of thoracolumbar UIV was strongly predicted by their baseline cervical and thoracolumbar alignment. Despite their poor preoperative condition, these patients still experienced significant improvements in their thoracolumbar alignment and PROMs after surgery, irrespective of UIV selection. LEVEL OF EVIDENCE: IV.

Lumbar Spondylolisthesis Grading: Current Standards and Important Factors to Consider for Management.

Spondylolisthesis is a common condition with a prevalence of 4-6% in childhood and 5-10% in adulthood. The Meyerding Classification, developed in 1932, assigns grades (I to V) based on the degree of slippage observed on standing, neutral lateral lumbar radiographs. Despite its historical significance and reliability, more factors should be evaluated to predict spondylolisthesis progression, especially in low-grade cases. The manuscript highlights areas for improvement in spondylolisthesis classification, emphasizing the need for considering factors beyond vertebral slippage. Factors such as global and segmental alignment, pelvic incidence, overhang, the number of affected levels, and the use of lateral flexion-extension radiographs to assess for stability using the kyphotic angle and slippage degree are identified as crucial in predicting progression and determining effective management strategies.

Developing a risk score to inform the use of rhBMP-2 in adult spinal deformity surgery.

BACKGROUND: Recombinant human bone morphogenetic protein-2 (rhBMP-2) has not shown superior benefit overall in cost-effectiveness during adult spinal deformity (ASD) surgery. STUDY DESIGN/SETTING: Retrospective PURPOSE: Generate a risk score for pseudarthrosis to inform the utilization of rhBMP-2, balancing costs against quality of life and complications. METHODS: ASD patients with 3-year data were included. Quality of life gained was calculated from ODI to SF-6D and translated to quality-adjusted life years (QALYs). Cost was calculated using the PearlDiver database and CMS definitions for complications and comorbidities. Established weights were generated for predictive variables via logistic regression to yield a predictive risk score for pseudarthrosis that accounted for frailty, diabetes, depression, ASA grade, thoracolumbar kyphosis and three-column osteotomy use. Risk score categories, established via conditional inference tree (CIT)-derived thresholds were tested for cost-utility of rhBMP-2 usage, controlling for age, prior fusion, and baseline deformity and disability. RESULTS: 64% of ASD patients received rhBMP-2 (308/481). There were 17 (3.5%) patients that developed pseudarthrosis. rhBMP-2 use overall did not lower pseudarthrosis rates (OR: 0.5, [0.2-1.3]). Pseudarthrosis rates for each risk category were: No Risk (NoR) 0%; Low-Risk (LowR) 1.6%; Moderate Risk (ModR) 9.3%; High-Risk (HighR) 24.3%. Patients receiving rhBMP-2 had similar QALYs overall to those that did not (0.163 vs. 0.171, p = .65). rhBMP-2 usage had worse cost-utility in the LowR cohort (p < .001). In ModR patients, rhBMP-2 usage had equivocal cost-utility ($53,398 vs. $61,581, p = .232). In the HighR cohort, the cost-utility was reduced via rhBMP-2 usage ($98,328 vs. $211,091, p < .001). CONCLUSION: Our study shows rhBMP-2 demonstrates effective cost-utility for individuals at high risk for developing pseudarthrosis. The generated score can aid spine surgeons in the assessment of risk and enhance justification for the strategic use of rhBMP-2 in the appropriate clinical contexts. LEVEL OF EVIDENCE: III.

Crossing the Cervicothoracic Junction: A Biomechanical Investigation of C7 vs T1 Caudal Selection's Effect on Adjacent Segment Motion in Posterior Cervical Fusion.

STUDY DESIGN: Biomechanical Study. OBJECTIVE: This study aims to evaluate the biomechanical adjacent segment effects of multi-level posterior cervical fusion constructs that terminate at C7 compared to those that terminate at T1 in cadaveric specimens. BACKGROUND: The cervicothoracic junction poses unique challenges for spine surgeons. Deciding to terminate multi-level posterior cervical fusion constructs at C7 or extend them across the cervicothoracic junction remains a controversial issue. METHODS: Six cadaveric specimens underwent biomechanical testing in the intact state and after instrumentation with constructs from C3 and terminating at either C7 or T1. Range of motion (ROM) was assessed in flexion-extension, lateral bending, and axial rotation globally and at cranial and caudal adjacent segments. RESULTS: There was a significant decrease in overall flexion/extension by both C7 (-35.5°, P=0.002) and T1 (-39.8°, P=0.002) instrumentation compared to the intact spine. T1 instrumentation had significantly lower (-4.3°, P=0.008) flexion/extension ROM compared to C7 instrumentation. There were significant decreases in axial rotation by both C7 (-31.4°, P=0.009) and T1 (-36.8°, P=0.009) instrumentation compared to the intact spine, but no significant differences were observed between the two. There were also significant decreases in lateral bending by both C7 (-27.9°, P=0.022) and T1 (-33.7°, P=0.022) instrumentation compared to the intact spine, but no significant differences were observed between the two. No significant differences were observed in ROM at cranial or caudal adjacent segments between constructs terminating at C7 and those extending to T1. CONCLUSION: This biomechanical investigation demonstrates that constructs that cross the cervicothoracic junction experience less overall spinal motion in flexion-extension compared to those that terminate at C7. However, contrary to prior studies there is no difference in cranial and caudal adjacent segment motion. Surgeons should make clinical decisions regarding the caudal extent of fusion in multi-level posterior cervical fusions without major concerns about adjacent segment motion.

One-Level versus Two-Level Anterior Lumbar Interbody Fusion (ALIF) from L4-S1: Comparison of Complications, Alignment, and Patient Outcomes.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: Compare outcomes in patients undergoing one-level or two-level anterior lumbar interbody fusion (ALIF) at L4-S1. BACKGROUND: Although ALIF may deliver restoration of lumbar lordosis and improvement in clinical outcomes, it also carries risk of complications including major vascular injury. Whether one-level and two-level ALIF offers similar outcomes is not known. METHODS: Adults who underwent one-level L4-L5 or L5-S1 ALIF and two-level L4-S1 ALIF at a single academic institution were identified. Patient demographics, procedural characteristics, improvement in spinopelvic alignment, and one-year postoperative patient-reported outcome measures (PROMs) and complications were compared. Multivariate regression analyses, accounting for age, gender, and Charlson Comorbidity Index (CCI), were also performed. RESULTS: In total, 158 ALIF patients (111 one-level and 47 two-level) were included, with mean age of 51.4 years, 57.0% female, mean CCI of 1.2, and mean follow-up of 27.0 months. Surgical time (147.3 min vs. 124.6 min, P=0.002) and hospital length of stay (3.5 d vs. 2.9 d, P=0.036) were higher for two-level ALIF. One-year postoperatively, two-level ALIF patients had more caudal apex of lordosis (P=0.016) and 4.1 mm (P=0.002) and 2.0 mm (P=0.019) higher L4-L5 anterior and posterior disc heights, respectively. PROMs were not statistically different across groups (P>0.05). Finally, two-level ALIF patients were 10.9 times more likely to have in-hospital complications (P=0.040), such as intraoperative vascular injury (11.1% vs. 1.5%, P=0.040) or postoperative ileus (7.4% vs. 0.0%, P=0.027), than one-level ALIF patients. CONCLUSION: In this investigation with greater than one-year follow-up, two-level ALIF in the L4-S1 spine had higher procedural time, length of stay, and approach-related complications than one-level ALIF. Although there were minor improvements in alignment with two-level ALIF, PROMs were comparable with improvements from baseline to last follow-up. These findings may help surgeons carefully weigh the risks and benefits of one- versus two-level ALIF when determining surgical plans for patients. LEVEL OF EVIDENCE: IV.

Sagittal spinal alignment measurements and evaluation: Historical perspective.

Spinal alignment analysis play an important role in evaluating patients and planning surgical corrections for adult spinal deformity. The history of these parameters is relatively short with the first parameter, the Cobb angle, introduced in 1948 as part of an effort to improve scoliosis evaluation. New developments in the field were limited for nearly 30 years before better imaging technology encouraged new theories and later data about spinal alignment and the relationship between the spine and pelvis. These efforts would ultimately contribute to the creation of foundational spinal alignment parameters, including pelvic incidence, pelvic tilt, and sacral slope. By the 1990s, spinal alignment had become a sustained area of investigation for spinal surgeons and researchers. Novel alignment parameters have since been introduced as our knowledge has evolved and has allowed for valuable research that demonstrates the clinical and surgical value of alignment measurement. This manuscript will explore the history of spinal alignment analysis over the decades.

Thoracolumbar fusions for adult lumbar deformity show superior QALY gain and lower costs compared with upper thoracic fusions.

PURPOSE: Adult spinal deformity (ASD) patients with sagittal plane deformity (N) or structural lumbar/thoraco-lumbar (TL) curves can be treated with fusions stopping at the TL junction or extending to the upper thoracic (UT) spine. This study evaluates the impact on cost/cumulative quality-adjusted life year (QALY) in patients treated with TL vs UT fusion. METHODS: ASD patients with > 4-level fusion and 2-year follow-up were included. Index and total episode-of-care costs were estimated using average itemized direct costs obtained from hospital records. Cumulative QALY gained were calculated from preoperative to 2-year postoperative change in Short Form Six-Dimension (SF-6D) scores. The TL and UT groups comprised patients with upper instrumented vertebrae (UIV) at T9-T12 and T2-T5, respectively. RESULTS: Of 566 patients with type N or L curves, mean age was 63.2 ± 12.1 years, 72% were female and 93% Caucasians. Patients in the TL group had better sagittal vertical axis (7.3 ± 6.9 vs. 9.2 ± 8.1 cm, p = 0.01), lower surgical invasiveness (- 30; p < 0.001), and shorter OR time (- 35 min; p = 0.01). Index and total costs were 20% lower in the TL than in the UT group (p < 0.001). Cost/QALY was 65% lower (492,174.6 vs. 963,391.4), and 2-year QALY gain was 40% higher, in the TL than UT group (0.15 vs. 0.10; p = 0.02). Multivariate model showed TL fusions had lower total cost (p = 0.001) and higher QALY gain (p = 0.03) than UT fusions. CONCLUSION: In Schwab type N or L curves, TL fusions showed lower 2-year cost and improved QALY gain without increased reoperation rates or length of stay than UT fusions. LEVEL OF EVIDENCE: III.

Patient-reported Physical and Mental Health Outcomes Following Lumbar Spinal Fusion versus Total Hip and Total Knee Replacement.

BACKGROUND: Total hip and knee arthroplasty (THA/TKA) are reliable surgical procedures for alleviating pain and optimizing function. Spinal fusion has also been shown to be beneficial, however the comparative benefit of THA/TKA to lumbar spinal fusion is incompletely understood. METHODS: This study analyzed a single-center database of patients who underwent primary lumbar spinal fusion, elective primary TKA, or THA. Patient-reported outcome measures (PROMs) included Veterans-Rand (VR12) Physical and Mental Component Score (PCS/MCS) for TKA/THA and PROMIS (Patient-Reported Outcomes Measurement Information System) Global Mental and Physical Health (GPH/GMH) for spinal fusion. RESULTS: A total of 356 patients who underwent TKA, 290 who underwent THA, and 125 who underwent spinal fusion were included. Joint replacement patients were older, with higher body mass index in the TKA group. Spine patients had a lower improvement in physical health than the joint patients (TKA: 9.4 ± 11.2, THA: 15.2 ± 11.2, Spine: 6.2 ± 8.7, P < 0.001) and a lower proportion of patients reaching the minimal clinically important difference (MCID). Spine patients had higher GMH improvements compared with TKA patients (TKA: -1.1 ± 10.7, THA: 1.1 ± 11.9, Spine: 1.8 ± 8.4, P = 0.009) and the highest proportion of patients reaching the MCID. CONCLUSIONS: Spinal fusion, total knee arthroplasty, and total hip arthroplasty all significantly improved PROMs at 1-year follow-up. At baseline, spinal fusion patients had better physical function scores and worse mental health scores compared with joint arthroplasty patients, while spinal fusion resulted in mean smaller gains in patient reported physical function and higher gains in patient reported mental health function compared with arthroplasty.

Hip Osteoarthritis in Patients Undergoing Surgery for Severe Adult Spinal Deformity: Prevalence and Impact on Spine Surgery Outcomes.

BACKGROUND: Hip osteoarthritis (OA) is common in patients with adult spinal deformity (ASD). Limited data exist on the prevalence of hip OA in patients with ASD, or on its impact on baseline and postoperative alignment and patient-reported outcome measures (PROMs). Therefore, this paper will assess the prevalence and impact of hip OA on alignment and PROMs. METHODS: Patients with ASD who underwent L1-pelvis or longer fusions were included. Two independent reviewers graded hip OA with the Kellgren-Lawrence (KL) classification and stratified it by severity into non-severe (KL grade 1 or 2) and severe (KL grade 3 or 4). Radiographic parameters and PROMs were compared among 3 patient groups: Hip-Spine (hip KL grade 3 or 4 bilaterally), Unilateral (UL)-Hip (hip KL grade 3 or 4 unilaterally), or Spine (hip KL grade 1 or 2 bilaterally). RESULTS: Of 520 patients with ASD who met inclusion criteria for an OA prevalence analysis, 34% (177 of 520) had severe bilateral hip OA and unilateral or bilateral hip arthroplasty had been performed in 8.7% (45 of 520). A subset of 165 patients had all data components and were examined: 68 Hip-Spine, 32 UL-Hip, and 65 Spine. Hip-Spine patients were older (67.9 ± 9.5 years, versus 59.6 ± 10.1 years for Spine and 65.8 ± 7.5 years for UL-Hip; p < 0.001) and had a higher frailty index (4.3 ± 2.6, versus 2.7 ± 2.0 for UL-Hip and 2.9 ± 2.0 for Spine; p < 0.001). At 1 year, the groups had similar lumbar lordosis, yet the Hip-Spine patients had a worse sagittal vertebral axis (SVA) measurement (45.9 ± 45.5 mm, versus 25.1 ± 37.1 mm for UL-Hip and 19.0 ± 39.3 mm for Spine; p = 0.001). Hip-Spine patients also had worse Veterans RAND-12 Physical Component Summary scores at baseline (25.7 ± 9.3, versus 28.7 ± 9.8 for UL-Hip and 31.3 ± 10.5 for Spine; p = 0.005) and 1 year postoperatively (34.5 ± 11.4, versus 40.3 ± 10.4 for UL-Hip and 40.1 ± 10.9 for Spine; p = 0.006). CONCLUSIONS: This study of operatively treated ASD revealed that 1 in 3 patients had severe hip OA bilaterally. Such patients with severe bilateral hip OA had worse baseline SVA and PROMs that persisted 1 year following ASD surgery, despite correction of lordosis. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

What Is the Epidemiology of Cervical and Thoracic Spine Fractures?

BACKGROUND: Vertebral fractures are associated with enduring back pain, diminished quality of life, as well as increased morbidity and mortality. Existing epidemiological data for cervical and thoracic vertebral fractures are limited by insufficiently powered studies and a failure to evaluate the mechanism of injury. QUESTION/PURPOSE: What are the temporal trends in incidence, patient characteristics, and injury mechanisms of cervical and thoracic vertebral fractures in the United States from 2003 to 2021? METHODS: The United States National Electronic Injury Surveillance System-All Injury Program (NEISS-AIP) database collects data on all nonfatal injuries treated in US hospital emergency departments and is well suited to capture epidemiological trends in vertebral fractures. As such, the NEISS-AIP was queried from 2003 to 2021 for cervical and thoracic fractures. The initial search by upper trunk fractures yielded 156,669 injuries; 6% (9900) of injuries, with a weighted frequency of 638,999 patients, met the inclusion criteria. The mean age was 62 ± 25 years and 52% (334,746 of 638,999) of patients were females. Descriptive statistics were obtained. Segmented regression analysis, accounting for the year before or after 2019 when the NEISS sampling methodology was changed, was performed to assess yearly injury trends. Multivariable logistic regression models with age and sex as covariates were performed to predict injury location, mechanism, and disposition. RESULTS: The incidence of cervical and thoracic fractures increased from 2.0 (95% CI 1.4 to 2.7) and 3.6 (95% CI 2.4 to 4.7) per 10,000 person-years in 2003 to 14.5 (95% CI 10.9 to 18.2) and 19.9 (95% CI 14.5 to 25.3) in 2021, respectively. Incidence rates of cervical and thoracic fractures increased for all age groups from 2003 to 2021, with peak incidence and the highest rate of change in individuals 80 years or older. Most injuries occurred at home (median 69%), which were more likely to impact older individuals (median [range] age 75 [2 to 106] years) and females (median 61% of home injuries); injuries at recreation/sports facilities impacted younger individuals (median 32 [3 to 96] years) and male patients (median 76% of sports facility injuries). Falls were the most common injury mechanism across all years, with females more likely to be impacted than males. The proportion of admissions increased from 33% in 2003 to 50% in 2021, while the proportion of treated and released patients decreased from 53% to 35% in the same period. CONCLUSION: This epidemiological study identified a disproportionate increase in cervical and thoracic fracture incidence rates in patients older than 50 years from 2003 to 2021. Furthermore, high hospital admission rates were also noted resulting from these fractures. These findings indicate that current osteoporosis screening guidelines may be insufficient to capture the true population at risk of osteoporotic fractures, and they highlight the need to initiate screening at an earlier age. LEVEL OF EVIDENCE: Level III, prognostic study.

Impact of Gender on Peri-Operative Characteristics and Outcomes of Lumbar Spine Surgery: A Current Concepts Review.

The success of spine surgery is variable among patients. Finding reliable predictors of successful outcomes will not only maximize patient benefit, but also increase the cost effectiveness of surgery. Recent research has demonstrated the importance of patient specific factors in predicting patient outcomes, including gender. While many studies show that female patients present with worse pain and function preoperatively, there is conflicting data on whether male and female patients reap the same benefits from lumbar spine surgery. In this manuscript we review the current research on gender and sex differences in preoperative characteristics and post-operative outcomes and comment on the need for more studies to better elucidate the mechanism driving the conflicting evidence.