Analyzing Large Language Models' Responses to Common Lumbar Spine Fusion Surgery Questions: A Comparison Between ChatGPT and Bard.

OBJECTIVE: In the digital age, patients turn to online sources for lumbar spine fusion information, necessitating a careful study of large language models (LLMs) like chat generative pre-trained transformer (ChatGPT) for patient education. METHODS: Our study aims to assess the response quality of Open AI (artificial intelligence)'s ChatGPT 3.5 and Google's Bard to patient questions on lumbar spine fusion surgery. We identified 10 critical questions from 158 frequently asked ones via Google search, which were then presented to both chatbots. Five blinded spine surgeons rated the responses on a 4-point scale from 'unsatisfactory' to 'excellent.' The clarity and professionalism of the answers were also evaluated using a 5-point Likert scale. RESULTS: In our evaluation of 10 questions across ChatGPT 3.5 and Bard, 97% of responses were rated as excellent or satisfactory. Specifically, ChatGPT had 62% excellent and 32% minimally clarifying responses, with only 6% needing moderate or substantial clarification. Bard's responses were 66% excellent and 24% minimally clarifying, with 10% requiring more clarification. No significant difference was found in the overall rating distribution between the 2 models. Both struggled with 3 specific questions regarding surgical risks, success rates, and selection of surgical approaches (Q3, Q4, and Q5). Interrater reliability was low for both models (ChatGPT: k = 0.041, p = 0.622; Bard: k = -0.040, p = 0.601). While both scored well on understanding and empathy, Bard received marginally lower ratings in empathy and professionalism. CONCLUSION: ChatGPT3.5 and Bard effectively answered lumbar spine fusion FAQs, but further training and research are needed to solidify LLMs' role in medical education and healthcare communication.

An overview of magnesium-based implants in orthopaedics and a prospect of its application in spine fusion.

Due to matching biomechanical properties and significant biological activity, Mg-based implants present great potential in orthopedic applications. In recent years, the biocompatibility and therapeutic effect of magnesium-based implants have been widely investigated in trauma repair. In contrast, the R&D work of Mg-based implants in spinal fusion is still limited. This review firstly introduced the general background for Mg-based implants. Secondly, the mechanical properties and degradation behaviors of Mg and its traditional and novel alloys were reviewed. Then, different surface modification techniques of Mg-based implants were described. Thirdly, this review comprehensively summarized the biological pathways of Mg degradation to promote bone formation in neuro-musculoskeletal circuit, angiogenesis with H-type vessel formation, osteogenesis with osteoblasts activation and chondrocyte ossification as an integrated system. Fourthly, this review followed the translation process of Mg-based implants via updating the preclinical studies in fracture fixation, sports trauma repair and reconstruction, and bone distraction for large bone defect. Furthermore, the pilot clinical studies were involved to demonstrate the reliable clinical safety and satisfactory bioactive effects of Mg-based implants in bone formation. Finally, this review introduced the background of spine fusion surgeryand the challenges of biological matching cage development. At last, this review prospected the translation potential of a hybrid Mg-PEEK spine fusion cage design.

An evidence based conceptual framework for the multifactorial understanding of proximal junctional kyphosis.

Introduction: Adult spinal deformity (ASD) is a debilitating pathology that arises from a variety of etiologies. Spinal fusion surgery is the mainstay of treatment for those who do not achieve symptom relief with conservative interventions. Fusion surgery can be complicated by a secondary deformity termed proximal junctional kyphosis (PJK). Research question: This scoping review evaluates the modern body of literature analyzing risk factors for PJK development and organizes these factors according to a multifactorial framework based on mechanical, tissue or demographic components. Materials and methods: An extensive search of the literature was performed in PubMed and Embase back to the year 2010. Articles were assessed for quality. All risk factors that were evaluated and those that significantly predicted the development of PJK were compiled. The frequency that a risk factor was predictive compared to the number of times it was evaluated was calculated. Results: 150 articles were reviewed. 57.3% of papers were of low quality. 76% of risk factors analyzed were focusing on the mechanical contribution to development of PJK versus only 5% were focusing on the tissue-based contribution. Risk factors that were most frequently predictive compared to how often they were analyzed were Hounsfield Units of vertebrae, UIV disc degeneration, paraspinal muscle cross sectional area and fatty infiltration, ligament augmentation, instrument characteristics, postoperative hip and lower extremity radiographic metrics, and postoperative teriparatide supplementation. Discussion and conclusion: This review finds a multifactorial framework accounting for mechanical, patient and tissue-based risk factors will improve the understanding of PJK development.

Diabetes increases risk of lumbar spinal fusion complications: association with altered structure of newly formed bone at the fusion site.

Diabetes predisposes to spine degenerative diseases often requiring surgical intervention. However, the statistics on the prevalence of spinal fusion success and clinical indications leading to the revision surgery in diabetes are conflicting. The purpose of the presented retrospective observational study was to determine the link between diabetes and lumbar spinal fusion complications using a database of patients (n = 552, 45% male, age 54 ± 13.7 years) residing in the same community and receiving care at the same health care facility. Outcome measures included clinical indications and calculated risk ratio (RR) for revision surgery in diabetes. Paravertebral tissue recovered from a non-union site of diabetic and nondiabetic patients was analyzed for microstructure of newly formed bone. Diabetes increased the RR for revision surgery due to non-union complications (2.80; 95% CI, 1.12-7.02) and degenerative processes in adjacent spine segments (2.26; 95% CI, 1.45-3.53). In diabetes, a risk of revision surgery exceeded the RR for primary spinal fusion surgery by 44% (2.36 [95% CI, 1.58-3.52] vs 1.64 [95% CI, 1.16-2.31]), which was already 2-fold higher than diabetes prevalence in the studied community. Micro-CT of bony fragments found in the paravertebral tissue harvested during revision surgery revealed structural differences suggesting that newly formed bone in diabetic patients may be of compromised quality, as compared with that in nondiabetic patients. In conclusion, diabetes significantly increases the risk of unsuccessful lumbar spine fusion outcome requiring revision surgery. Diabetes predisposes to the degeneration of adjacent spine segments and pseudoarthrosis at the fusion sites, and affects the structure of newly formed bone needed to stabilize fusion.

Pre-operative carbohydrate drink in pediatric spine fusion: randomized control trial.

PURPOSE: As rapid discharge protocols for pediatric spine fusion shorten stays, gastrointestinal (GI) complications are uncovered and cause delays in discharge. A pre-operative carbohydrate (CHO) drink has been shown to improve perioperative GI symptoms and functional return but has not been examined in pediatric spine patients. We aimed to determine if a preoperative CHO drink is safe in pediatric spine fusion patients, and if it improves their comfort scores and return of bowel function. METHODS: We prospectively randomized ASA-1 and -2 pediatric spine fusion patients to either a pre-anesthesia carbohydrate drink 2 h prior to surgery or to a control group (standard 8 h NPO), blinded to surgical team. We documented time to return to flatus, bowel movement, GI symptoms, and comfort scores for 72 h post-operatively or until discharge. RESULTS: 62 patients were randomized. There was no significant differences between the groups' pre-operative characteristics, surgical details, nor post-operative morphine dose equivalents, except for EBL (405 cc control, 340 cc CHO drink, p = 0.044). There were no perioperative complications related to ingestion of the CHO drink. CHO group had a positive trend for earlier return of flatus (21% vs. 3% return at 12 h), and comfort scores for anxiety and abdominal pain, but no statistically significant differences. There was no difference in length of stay or time to first bowel movement. CONCLUSION: There were no complications related to ingestion of a CHO drink 2 h prior to pediatric spinal fusion surgery. Further studies are needed to develop a study blinded to the participants with larger sample size. Level of evidence I.

Long-Term Incidence of Adjacent Segmental Pathology After Minimally Invasive vs. Open Transforaminal Lumbar Interbody Fusion.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To compare the incidence of adjacent segmental pathology (ASP) following minimally invasive (MI) vs open transforaminal lumbar interbody fusion (TLIF) and to identify factors linked to ASP requiring reoperation. METHODS: This retrospective study reviewed the outcomes of patients who underwent MI-TLIF or open TLIF. Radiographic ASP (RASP) was evaluated using X-ray imaging to distinguish between degenerative changes, spondylolisthesis, and instability in the adjacent spinal segment. Clinical ASP (CASP) was assessed with the visual analog scale score for leg and back pain and the Oswestry disability index. Patient data were collected 1, 2, 5, and 10 years postoperatively. The timing and frequency of ASP reoperation were analyzed. RESULTS: Five years postoperatively, the RASP rate was 35.23% and 45.95% in the MI-TLIF and open TLIF groups. The frequency of CASP differed significantly between the MI-TLIF and open TLIF groups at 1 year postoperatively. The rates of RASP, CASP, and ASP necessitating reoperation were not significantly different 10 years postoperatively. Cranial facet violation significantly affected ASP in both groups. In the open TLIF group, preoperative adjacent segment disc degeneration significantly influenced ASP. CONCLUSION: The RASP rate at 5 years postoperatively and the CASP rate at 1 year postoperatively differed significantly between groups. There was no difference in the rate of ASP requiring reoperation. Cranial facet violation is a crucial driving factor for ASP after both surgical procedures.

Minimally invasive surgery versus standard posterior approach in the treatment of adolescent idiopathic scoliosis: a 2-year follow-up retrospective study.

PURPOSE: This is a monocentric retrospective controlled study that compares the safety and efficacy of posterior minimally invasive surgery (MISS) to standard posterior spinal fusion (PSF) surgery in adolescent idiopathic scoliosis (AIS). METHODS: We retrospectively collected 111 patients with Lenke type 1-6 AIS who were treated with MIS (n = 47) or PSF (n = 64) between February 2019 and January 2021 with a 2-year clinical and radiological follow-up. MIS technique was applied via two midline noncontiguous skin incisions ranging from 3 to 7 cm in length, so we obtained the arthrodesis only in the exposed tract, passing the rods below the fascia, avoiding the complete muscular sparing. Values of Cobb angles degrees were collected to study the correction rate of the structural major curve. Postoperative AP direct radiography and preoperative AP direct radiography were compared with the last follow-up examination. Operative time, preoperative hemoglobin (Hb) and second postoperative day Hb, full length of hospitalization, time to achieve verticalization and time to remove the drainage were recorded. NRS medium score was assessed immediately after surgery and during the whole postoperative rehabilitation treatment to estimate pain reduction. Complications were collected postoperatively and throughout the whole follow-up period. RESULTS: There was no significant difference between the two groups in terms of radiographic and clinical features. The correction rates of the structural curve resulted to be not significantly different between MISS and PSF (64.6 ± 11.7 vs 60.9 ± 13.2, p = 0.1292) as well as for the correction rate of the secondary curve between the two compared techniques (59.1 ± 13.2 vs 59.2 ± 12.4, p = 0.9865). The two groups had comparable operative time (210 min vs 215 min). The MIS group had a significantly lower reduction of postoperative Hb in comparison with PSF group (2.8 ± 1.3 mg/dl vs 4.3 ± 1.5 mg/dl, p < 0.0001). The postoperative NRS score was lower in MIS group (1.9 ± 0.8 vs 3.3 ± 1.3). PSF group was observed to have a significantly longer period of hospitalization than MIS (5.2 ± 1.4 days vs 6.3 ± 2.9 days, p = 0.206). Complications were more frequent in PSF group rather than in MFS group. CONCLUSIONS: MISS is a safe and capable alternative to PSF for AIS patients with curves < 70°, with analogue capacity of scoliosis correction and same operative time and with advantages in blood loss, length of stay and postoperative pain.

Injectable bioactive poly(propylene fumarate) and polycaprolactone based click chemistry bone cement for spinal fusion in rabbits.

Degenerative spinal pathology is a widespread medical issue, and spine fusion surgeries are frequently performed. In this study, we fabricated an injectable bioactive click chemistry polymer cement for use in spinal fusion and bone regrowth. Taking advantages of the bioorthogonal click reaction, this cement can be crosslinked by itself eliminating the addition of a toxic initiator or catalyst, nor any external energy sources like UV light or heat. Furthermore, nano-hydroxyapatite (nHA) and microspheres carrying recombinant human bone morphogenetic protein-2 (rhBMP-2) and recombinant human vascular endothelial growth factor (rhVEGF) were used to make the cement bioactive for vascular induction and osteointegration. After implantation into a rabbit posterolateral spinal fusion (PLF) model, the cement showed excellent induction of new bone formation and bridging bone, achieving results comparable to autograft control. This is largely due to the osteogenic properties of nano-hydroxyapatite (nHA) and the released rhBMP-2 and rhVEGF growth factors. Since the availability of autograft sources is limited in clinical settings, this injectable bioactive click chemistry cement may be a promising alternative for spine fusion applications in addressing various spinal conditions.

A Novel Intraoperative CT Navigation System for Spinal Fusion Surgery in Lumbar Degenerative Disease: Accuracy and Safety of Pedicle Screw Placement.

Background: In recent years, intraoperative computed tomography (CT) navigation has become widely used for the insertion of pedicle screws in spinal fusion surgery. However, conventional intraoperative CT navigation may be impaired by infrared interference between the infrared camera and surgical instruments, which can lead to the misplacement of pedicle screws. Recently, a novel intraoperative CT navigation system, NextAR, has been developed. It uses a small infrared camera mounted on surgical instruments within the surgical field. NextAR navigation can minimize the problem of infrared interference and be expected to improve the accuracy of pedicle screw placement. Methods: This study investigated the accuracy of pedicle screw insertion under NextAR navigation in spinal fusion surgery for lumbar degenerative diseases. The accuracy of pedicle screw placement was evaluated in 15 consecutive patients using a CT grading scale. Results: Screw perforation occurred in only 1 of the total 70 screws (1.4%). Specifically, there was one grade 1 perforation within 2 mm, but no perforations larger than 2 mm. There were no reoperations or neurological complications due to screw misplacement. Conclusions: NextAR navigation can provide high accuracy for pedicle screw insertion and help ensure safe spinal fusion surgery for lumbar degenerative diseases.

Surgeon Preference Regarding Wound Dressing Management in Lumbar Fusion Surgery: An AO Spine Global Cross-Sectional Study.

OBJECTIVE: To evaluate the global practice pattern of wound dressing use after lumbar fusion for degenerative conditions. METHODS: A survey issued by AO Spine Knowledge Forums Deformity and Degenerative was sent out to AO Spine members. The type of postoperative dressing employed, timing of initial dressing removal, and type of subsequent dressing applied were investigated. Differences in the type of surgery and regional distribution of surgeons' preferences were analyzed. RESULTS: Right following surgery, 60.6% utilized a dry dressing, 23.2% a plastic occlusive dressing, 5.7% glue, 6% a combination of glue and polyester mesh, 2.6% a wound vacuum, and 1.2% other dressings. The initial dressing was removed on postoperative day 1 (11.6%), 2 (39.2%), 3 (20.3%), 4 (1.7%), 5 (4.3%), 6 (0.4%), 7 or later (12.5%), or depending on drain removal (9.9%). Following initial dressing removal, 75.9% applied a dry dressing, 17.7% a plastic occlusive dressing, and 1.3% glue, while 12.1% used no dressing. The use of no additional coverage after initial dressing removal was significantly associated with a later dressing change (p < 0.001). Significant differences emerged after comparing dressing management among different AO Spine regions (p < 0.001). CONCLUSION: Most spine surgeons utilized a dry or plastic occlusive dressing initially applied after surgery. The first dressing was more frequently changed during the first 3 postoperative days and replaced with the same type of dressing. While dressing policies tended not to vary according to the type of surgery, regional differences suggest that actual practice may be based on personal experience rather than available evidence.

Bioactive Moldable Click Chemistry Polymer Cement with Nano-Hydroxyapatite and Growth Factor-Enhanced Posterolateral Spinal Fusion in a Rabbit Model.

Spinal injuries or diseases necessitate effective fusion solutions, and common clinical approaches involve autografts, allografts, and various bone matrix products, each with limitations. To address these challenges, we developed an innovative moldable click chemistry polymer cement that can be shaped by hand and self-cross-linked in situ for spinal fusion. This self-cross-linking cement, enabled by the bioorthogonal click reaction, excludes the need for toxic initiators or external energy sources. The bioactivity of the cement was promoted by incorporating nanohydroxyapatite and microspheres loaded with recombinant human bone morphogenetic protein-2 and vascular endothelial growth factor, fostering vascular induction and osteointegration. The release kinetics of growth factors, mechanical properties of the cement, and the ability of the scaffold to support in vitro cell proliferation and differentiation were evaluated. In a rabbit posterolateral spinal fusion model, the moldable cement exhibited remarkable induction of bone regeneration and effective bridging of spine vertebral bodies. This bioactive moldable click polymer cement therefore presents a promising biomaterial for spinal fusion augmentation, offering advantages in safety, ease of application, and enhanced bone regrowth.

Aborted AIS spinal fusion due to persistent loss of IONM: which patients are at greatest risk?

PURPOSE: Determine peri-operative risk factors predictive for prematurely stopping surgery prior to completion of deformity correction due to intra-operative neuromonitoring changes. METHODS: A single institution retrospective review of adolescent idiopathic scoliosis (AIS) patients that underwent spinal fusion for curves greater than 70°. Cases aborted due to persistent loss of IONM were compared to completed cases. Demographic, radiographic, neurologic, and surgical information was reviewed. RESULTS: There were 453 total cases. Nine (9/453: (2%)) cases were aborted due to persistent loss of IONM, and 4 (4/453; (0.88%)) awoke with a neurologic deficit. Comparing to the 444 completed cases, pre-operative risk factors associated with case abortion were older age (15.3 vs. 13.8 years; p = 0.02), sex (male) (66.7% vs. 20.3%, p = 0.004), and larger cobb angles (87.6° vs. 79.2°; p = 0.01). Being male increased the risk of case abortion: 7.9X. Intraoperative risk factors associated with case abortion were combined anterior/posterior approach (ASF/PSF) (44.4% vs. 7.2%; p = 0.003) and increased index procedure EBL (1127 vs. 769 mL; p = 0.043). ASF/PSF increased the risk: 10.3X. Four (4/9;44%) of the aborted cases awoke with neurologic deficit. Motor strength returned at 2.3 days (0-18). Aborted cases returned to the OR after 12.6 ± 7.0 days (1-23) which was related to time to regain motor strength. CONCLUSION: Pre-operative risk factors for AIS case abortion due to persistent loss of IOMN are older age, males, with larger Cobb angles. Intraoperative risk factors are combined ASF/PSF and increased index procedure EBL. Independent risk factors were sex (male) and ASF/PSF which increased the risk 7.9X and 10.3X, respectively.

Effectiveness of vancomycin powder for preventing postoperative spinal infection.

OBJECTIVE: This study aimed to assess the effectiveness of Vancomycin Power (VP) and the occurrence of resistant organisms after four-year of routine VP use. METHODS: The study included 1063 patients who underwent posterior lumbar interbody fusion (PLIF) and transforaminal lumbar interbody fusion (TLIF) between January 2010 and February 2020. Intrawound VP was applied to all instrumented fusions starting in January 2016. The patients were divided into two groups: those who did not apply VP (non-VP) (n = 605) between 2010 and 2015, and those who did apply VP (VP) (n = 458) between 2016 and 2020. The baseline characteristics, clinical symptoms, infection rate, and causative organisms were compared between the two groups. RESULTS: The rate of PSI was not significantly different between the non-VP group (1.32 %, n = 8) and the VP group (1.09 %, n = 5). Although adjusted by diabetes mellitus, VP still did not show statistical significance (OR = 0.757 (0.245-2.345), p = 0.630). There were no critical complications that were supposed to relation with vancomycin powder. In the 13 cases of PSI, seven pathogens were isolated, with a gram-negative organism identified in the non-VP group. However, the type of organism was not significantly different between the two groups. CONCLUSIONS: The use of intrawound VP may not affect the PSI and occurrence of resistant organism and may not cause critical complications. Therefore, clinicians may decide whether to use VP for preventing PSI not worrying about its safety.

Randomized Trial of Augmented Pelvic Fixation in Patients Undergoing Thoracolumbar Fusion for Adult Spine Deformity: Initial Results from a Multicenter Randomized Trial.

BACKGROUND: The optimal configuration for spinopelvic fixation during multilevel spine fusion surgery for adult spine deformity remains unclear. Postoperative sacroiliac (SI) joint pain, S2AI screw loosening and implant breakage could be related to continued motion of the SI joint with use of only a single point of fixation across the SI joint. METHODS: Prospective, international, multicenter randomized controlled trial of 222 patients with adult spine deformity scheduled for multilevel (4 or more levels) spine fusion surgery with pelvic fixation. Subjects were randomized to sacroalar (S2) iliac (S2AI) screws alone for pelvic fixation or S2AI + triangular titanium implants placed cephalad to S2AI screws. Quad rod techniques were not allowed or used. Baseline spinal deformity measures were read by an independent radiologist. Site-reported perioperative adverse events were reviewed by a clinical events committee. Quality of life questionnaires and other clinical outcomes are in process with planned 2-year follow-up. RESULTS: One hundred thirteen participants were assigned to S2AI and 109 to S2AI + titanium triangular implants (TTI). 35/222 (16%) of all subjects had a history of SI joint pain or were diagnosed with SI joint pain during preoperative workup. Three-month follow-up was available in all but 4 subjects. TTI placement was successful in 106 of 109 (98%) subjects assigned to TTI. In 2 cases, TTI could not be placed due to anatomical considerations. Three TTI ventral iliac breaches were observed, all of which were managed non-surgically. One TTI subject had a transverse sacral fracture and 1 TTI subject had malposition of the implant requiring removal. CONCLUSIONS: SI joint pain is common in patients with adult spinal deformity who are candidates for multilevel spine fusion surgery. Concurrent placement of TTI parallel to S2AI screws during multilevel spine fusion surgery is feasible and safe. Further follow-up will help to determine the clinical value of this approach to augment pelvic fixation.

Development of an International AO Spine Guideline for the Use of Osteobiologics in Anterior Cervical Fusion and Decompression (AO-GO).

STUDY DESIGN: Methodological study for guideline development. OBJECTIVE: AO Spine Guideline for Using Osteobiologics (AO-GO) project for spine degenerative pathologies was an international, multidisciplinary collaborative initiative to identify and evaluate evidence on existing use of osteobiologics in Anterior Cervical Fusion and Decompression (ACDF). The aim was to formulate precisely defined, clinically relevant and internationally applicable guidelines ensuring evidence-based, safe and effective use of osteobiologics, considering regional preferences and cost-effectiveness. METHODS: Guideline was completed in two phases: Phase 1- evidence synthesis; Phase 2- recommendation development based on the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. In Phase 1, key questions identified by a panel of experts were addressed in a series of systematic reviews of randomized and non-randomized studies. In Phase 2, the GRADE approach was used to formulate a series of recommendations, including expert panel discussions via web calls and face-to-face meetings. DISCUSSION: AO-GO aims to bridge an important gap between evidence and use of osteobiologics in spine fusion surgeries. Owing to differences in osteobiologics preparation and functional characteristics, regulatory requirements for approval may vary, therefore it is highly likely that these products enter market without quality clinical trials. With a holistic approach the guideline aims to facilitate evidence-based, patient-oriented decision-making processes in clinical practice, thus stimulating further evidence-based studies regarding osteobiologics usage in spine surgeries. In Phase 3, the guideline will be disseminated and validated using prospectively collected clinical data in a separate effort of the AO Spine Knowledge Forum Degenerative in a global multicenter clinical study.

Managing Disease-Modifying Antirheumatic Drugs (DMARDs) for Patients Undergoing Elective Spine Surgery: A Pilot Survey.

Introduction: Patients affected by autoimmune pathologies such as rheumatoid arthritis require surgery for various reasons. However, the systemic inflammatory nature of these disease processes often necessitates therapy with disease-modifying antirheumatic drugs (DMARDs). Alteration of these agents in the perioperative period for surgery requires a careful risk-benefit analysis to limit disease flares, infection rates, and secondary revisions. We therefore queried North and South American practices for perioperative management of DMARDs in patients undergoing elective spine surgery. Methods: An institutional review board-approved pilot survey was disseminated to spine surgeons regarding how they managed DMARDs before, during, and after spine surgery. Results: A total of 47 spine surgeons responded to the survey, 37 of whom were neurosurgeons (78.7%) and 10 orthopedic surgeons (21.3%). Of the respondents, 80.9% were from North America, 72.3% were board-certified, 51.1% practiced in academic institutions, and 66.0% performed 50-150 spine surgeries per year. Most respondents consulted a rheumatologist before continuing or withholding a DMARD in the perioperative period (70.2%). As such, a majority of the spine surgeons in this survey withheld DMARDs at an average of 13.8 days before and 19.6 days after spine surgery. Of the spine surgeons who withheld DMARDs before and after spine surgery, the responses were variable with a trend toward no increased risk of postoperative complications. Conclusions: Based on the results of this pilot survey, we found a consensus among spine surgeons to withhold DMARDs before and after elective spine surgery.

Postoperative lordosis distribution index, patient reported outcome measures, and revision surgery following transforaminal lumbar interbody fusion.

Objective: Lordosis Distribution Index (LDI) is a new radiographic parameter associated with postoperative residual symptoms in patients undergoing Transforaminal Lumbar Interbody Fusion (TLIF). Recently, it has been applied on patients undergoing instrumented spine surgery, however not correlated to Patient Related Outcome Measures (PROMs). This study investigates whether the obtained the postoperative LDI after TLIF surgery correlates with the clinical outcome measured with PROMs. Methods: This study was based on prospectively obtained data in patients undergoing TLIF throughout 2017 at a Danish university hospital. Medical records and the DaneSpine Database were accessed to obtain preoperative, operative and follow-up data. Primary outcome was Oswestry Disability Index (ODI) 12 months postoperatively. Secondary outcomes included revision rate and additional PROMs. Results: 126 patients were included. 70 patients were classified with normolordosis (56 %), 42 hypolordosis (33 %) and 14 hyperlordosis (11 %). All groups experienced significant radiological changes undergoing surgery. Average reduction in ODI at 12 months postoperatively was -15.3 (±20.0). Minimally clinical important difference was achieved in 68 patients (54.0 %). No significant difference in PROMs between LDI-groups was observed in unadjusted or adjusted analyses. Revision surgery was performed in 8 patients with normolordosis (11.4 %), 7 hypolordosis (16.7 %) and 4 hyperlordosis (28.6 %). Conclusions: We found no significant correlation between postoperative LDI subgroups of normolordotic, hypo- or hyperlordotic patients and the clinical outcome of posterolateral fusion and TLIF surgery. A trend towards lower rate of revision surgery in the normolordotic group compared to the hypo- and hyperlordotic group was observed.

Long-term comparison of anterior (ALIF) versus transforaminal (TLIF) lumbar interbody fusion: a propensity score-matched register-based study.

PURPOSE: Anterior (ALIF) and transforaminal (TLIF) lumbar interbody fusion have shown similar clinical outcomes at short- and medium-term follow-ups. Possible advantages of ALIF in the long run could be better disc height and lumbar lordosis and reduced risk of adjacent segment disease. We aimed to study if ALIF could be associated with superior clinical outcomes than TLIF at long-term follow-up. METHODS: We analysed 535 patients treated with ALIF or TLIF of the L5-S1 spinal segment between 2007 and 2017 who completed long-term follow-up in a national spine registry database (NORspine). We defined treatment success after surgery as at least 30% improvement in Oswestry Disability Index (ODI) at long-term follow-up. Patients treated with ALIF and TLIF and who responded at long term were balanced by propensity score matching. The proportions of successfully treated patients within each group were compared by numbers and percentages with corresponding relative risk. RESULTS: The mean (95%CI) age of the total study population was 50 (49-51) years, and 264 (49%) were females. The mean (95%CI) preoperative ODI score was 40 (39-42), and 174 (33%) had previous spine surgery. Propensity score matching left 120 patients in each treatment group. At a median (95%CI) of 92 (88-97) months after surgery, we found no difference in proportions successfully treated patients with ALIF versus TLIF (68 (58%) versus 77 (65%), RR (95%CI) = 0.88 (0.72 to1.08); p = 0.237). CONCLUSIONS: This propensity score-matched national spine register study of patients treated with ALIF versus TLIF of the lumbosacral junction found no differences in proportions of successfully treated patients at long-term follow-up. LEVEL OF EVIDENCE I: Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.

Evaluating the safe zone for lumbar pedicle screws: are midline crossing screws indicative of pedicle breach?

BACKGROUND CONTEXT: Pedicle screw breach (PSB) is not uncommon following lumbar instrumentation, and in some instances, it may lead to vascular and/or neurologic complications. Previous literature suggested that screws crossing the vertebral midline on an anterior-posterior (AP) radiograph (or midsagittal on CT) are concerning for medial pedicle breach. OBJECTIVE: Our primary aim was to map out the safe zones (SZ) of bilateral pedicle instrumentation and their relationship at each lumbar vertebral level. Our secondary aim was to evaluate the presence of SZs' intersection at each lumbar level, denoting safe midline pedicle screw crossing not otherwise associated with medial pedicle breach. STUDY DESIGN/SETTING: Retrospective Anatomical Study. PATIENT SAMPLE: Adult patients in the from "The Cancer Imaging Archive" (TCIA) database who have not had thoraco-lumbo-sacral fusion. OUTCOME MEASURES: Physiologic measures obtained through 3D analysis of CT images and virtual pedicle screws. METHOD: CT scans of 51 patients were randomly selected from "The Cancer Imaging Archive" (TCIA) online database for analysis. The Sectra 3D Spine software was used to create 3D renderings, place virtual screws, and make measurements. At each lumbar vertebra, the right and left pedicle corridors were mapped. At each pedicle, two screw positions were templated, the "medial limit screw" (MLS) and the "lateral limit screw" (LLS). Each limit screw was the most extreme position that the screw could exist in without causing a medial or lateral breach. The safe zone was defined as the zone between MLS and LLS. Measurements were taken for each level (between L1 and L5) and side (Left, Right). RESULTS: A total of 253 lumbar vertebrae from 51 patients (mean age 53.1, 56.9% male) were included. Two vertebrae from two patients were removed for poor image quality. Out of the 506 screw positions analyzed in our study, 97.4% had overlapping SZ and crossed the midplane without medial pedicle breach. The significant factors (p<.01) for safe midplane-crossing screws included: the screw length (L1-L5); the laterality of the screw entry point (L1-L4); and the pedicle diameter (L2 and L5). CONCLUSIONS: A midline crossing pedicle screw on a lumbar AP radiograph is not necessarily indicative of a medial pedicle screw breach. Anatomical (ie, larger pedicle diameter) and technical (ie, longer screws, and lateral entry points) factors allow for safety zone intersections and indicate safe midline crossing by pedicle screws.

Spondylodiscitis instrumented fusion, a prospective case series on a standardized neurosurgical protocol with long term follow up.

PURPOSE: To investigate the fusion construct properties, construct length, intervertebral prosthesis (IVP) selection, bone grafting methods, complications management, and follow-up outcomes of spondylodiscitis fusion. METHOD: This case series was conducted in Al-Zahra University referral hospital from March 2016 to November 2021. All the surgery-eligible patients were enrolled. Those who did not participate or failed the neurosurgical intervention were excluded. A unified neurosurgical protocol was defined. After operation and follow-up, all variables were documented. IBM SPSS v.26 was used for data analysis. P-value ≤ 0.05 was considered significant. RESULT: Ninety-two patients were reviewed in the final analysis with 65.2 % males. The mean age was 55.07 ± 14.22 years old. The most frequent level of pathology and surgery was the lumbar spine (48.9 %). Short and long constructs were almost equally used (57.6 and 42.4 %, respectively). Bone graft mixture was the dominant IVP (75 %). The most frequent persistent postoperative symptom was back pain (55.4 %), while the neurological deficits resolution rate was 76.7 %. The fusion rate was 92.3 %. Proximal junctional kyphosis incidence was 16.3 % and had a significant association with on-admission neurological symptoms, thoracic and thoracolumbar junction involvements (p < 0.05). Follow-up Oswestry disability index scores showed 44.6 % of the patients had mild or no functional disabilities. Advanced age, On-admission deficits, comorbidities, titanium cages, and poor fusion status were associated with poor functional outcomes and higher mortality rates (P < 0.05). CONCLUSION: The introduced neurosurgical protocol could effectively achieve acceptable SD treatment, spine stabilization, and fusion with low long-term surgical complications. Autologous bone graft mixture in comparison to titanium cages showed a higher fusion rate with a lower mortality rate. Patients with older age, neurological symptoms, and comorbidities are expected to experience less favorable clinical outcomes.