Search

Background: Spinal implants' longevity is crucial, but titanium alloys, while advantageous, lack strong bone integration. This study aimed to achieve better osseointegration rates by utilizing the ability of boron compounds to transform stem cells in the vertebra into osteoblasts. Method: Twenty male albino rabbits were divided into control (n = 10) and experimental (n = 10) groups. Control group received titanium alloy pedicle screws, while experimental group received boron-coated titanium alloy screws. Under general anesthesia, screws were inserted into the L6 and L7 lumbar spines. After 16 weeks, all animals were euthanized for histological examination. Vertebra samples underwent decalcification and H&E staining. Microscopic examination assessed osseointegration, necrosis, fibrosis, and vascularization using a triple scoring system by two blinded observers. Result: In the boron-coated titanium alloy group, all subjects exhibited osseointegration, with 50% showing focal, 40% moderate, and 10% complete osseointegration. In the titanium alloy group, 90% showed osseointegration (70% focal, 10% moderate, and 10% complete).The differences between the groups were not statistically significant (p = 0.302). Focal necrosis rates were similar between groups, with 50.0% in the titanium alloy and 60.0% in the boron-coated group (p = 0.653).Fibrosis was absent in the titanium alloy group but present in the boron-coated group, albeit with lower rates of focal fibrosis (20.0%). However, the difference was not statistically significant (p = 0.086).Vascularization patterns showed no significant difference between groups. Conclusion: Boron-coated titanium alloy pedicle screws provided osseointegration rates comparable to standard titanium screws and exhibited acceptable levels of necrosis and fibrosis. With stronger biomechanical properties, they could be a better alternative to currently used titanium screws. [ABSTRACT FROM AUTHOR]

Dynamic tracking of spinal instrumentation could facilitate real-time evaluation of hardware integrity and in so doing alert patients/clinicians of potential failure(s). Critically, no method yet exists to continually monitor the integrity of spinal hardware and by proxy the process of spinal arthrodesis; as such hardware failures are often not appreciated until clinical symptoms manifest. Accordingly, herein, we report on the development and engineering of a bio-adhesive metal detector array (BioMDA), a potential wearable solution for real-time, non-invasive positional analyses of osseous implants within the spine. The electromagnetic coupling mechanism and intimate interfacial adhesion enable the precise sensing of the metallic implants position without the use of radiation. The customized decoupling models developed facilitate the precise determination of the horizontal and vertical positions of the implants with incredible levels of accuracy (e.g., <0.5 mm). These data support the potential use of BioMDA in real-time/dynamic postoperative monitoring of spinal implants. No method exists for real-time evaluation of the status of spinal implants. Here, the authors developed a bio-adhesive metal detector array (BioMDA) that provides a wearable, non-invasive solution for positional analyses of osseous implants within the spine. [ABSTRACT FROM AUTHOR]

Introduction The cervical spine, pivotal for mobility and overall body function, can be affected by cervical spondylosis, a major contributor to neural disorders. Prevalent in both general and military populations, especially among pilots, cervical spondylosis induces pain and limits spinal capabilities. Anterior Cervical Discectomy and Fusion (ACDF) surgery, proposed by Cloward in the 1950s, is a promising solution for restoring natural cervical curvature. The study objective was to investigate the impacts of ACDF implant design on postsurgical cervical biomechanics and neurorehabilitation outcomes by utilizing a biofield head-neck finite element (FE) platform that can facilitate scenario-specific perturbations of neck muscle activations. This study addresses the critical need to enhance computational models, specifically FE modeling, for ACDF implant design. Materials and Methods We utilized a validated head-neck FE model to investigate spine–implant biomechanical interactions. An S-shaped dynamic cage incorporating titanium (Ti) and polyetheretherketone (PEEK) materials was modeled at the C4/C5 level. The loading conditions were carefully designed to mimic helmet-to-helmet impact in American football, providing a realistic and challenging scenario. The analysis included intervertebral joint motion, disk pressure, and implant von Mises stress. Results The PEEK implant demonstrated an increased motion in flexion and lateral bending at the contiguous spinal (C4/C5) level. In flexion, the Ti implant showed a modest 5% difference under 0% activation conditions, while PEEK exhibited a more substantial 14% difference. In bending, PEEK showed a 24% difference under 0% activation conditions, contrasting with Ti's 17%. The inclusion of the head resulted in an average increase of 18% in neck angle and 14% in C4/C5 angle. Disk pressure was influenced by implant material, muscle activation level, and the presence of the head. Polyetheretherketone exhibited lower stress values at all intervertebral disc levels, with a significant effect at the C6/C7 levels. Muscle activation level significantly influenced disk stress at all levels, with higher activation yielding higher stress. Titanium implant consistently showed higher disk stress values than PEEK, with an orders-of-magnitude difference in von Mises stress. Excluding the head significantly affected disk and implant stress, emphasizing its importance in accurate implant performance simulation. Conclusions This study emphasized the use of a biofidelic head-neck model to assess ACDF implant designs. Our results indicated that including neck muscles and head structures improves biomechanical outcome measures. Furthermore, unlike Ti implants, our findings showed that PEEK implants maintain neck motion at the affected level and reduce disk stresses. Practitioners can use this information to enhance postsurgery outcomes and reduce the likelihood of secondary surgeries. Therefore, this study makes an important contribution to computational biomechanics and implant design domains by advancing computational modeling and theoretical knowledge on ACDF–spine interaction dynamics. [ABSTRACT FROM AUTHOR]

Cutibacterium acnes (C. acnes) previously named Propionibacterium acnes (P. acnes) has been increasingly recognized by spine surgeons as a cause of indolent postsurgical 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. [ABSTRACT FROM AUTHOR]

3D-printing technology has revolutionized spinal implant manufacturing, particularly in developing personalized and custom-fit titanium interbody fusion cages. These cages are pivotal in supporting inter-vertebral stability, promoting bone growth, and restoring spinal alignment. This article reviews the latest advancements in 3D-printed titanium interbody fusion cages, emphasizing their relevance in modern personalized surgical spine care protocols applied to common clinical scenarios. Furthermore, the authors review the various printing and post-printing processing technologies and discuss how engineering and design are deployed to tailor each type of implant to its patient-specific clinical application, highlighting how anatomical and biomechanical considerations impact their development and manufacturing processes to achieve optimum osteoinductive and osteoconductive properties. The article further examines the benefits of 3D printing, such as customizable geometry and porosity, that enhance osteointegration and mechanical compatibility, offering a leap forward in patient-specific solutions. The comparative analysis provided by the authors underscores the unique challenges and solutions in designing cervical, and lumbar spine implants, including load-bearing requirements and bioactivity with surrounding bony tissue to promote cell attachment. Additionally, the authors discuss the clinical outcomes associated with these implants, including the implications of improvements in surgical precision on patient outcomes. Lastly, they address strategies to overcome implementation challenges in healthcare facilities, which often resist new technology acquisitions due to perceived cost overruns and preconceived notions that hinder potential savings by providing customized surgical implants with the potential for lower complication and revision rates. This comprehensive review aims to provide insights into how modern 3D-printed titanium interbody fusion cages are made, explain quality standards, and how they may impact personalized surgical spine care. [ABSTRACT FROM AUTHOR]

(1) Background: The kinematic characteristics of disc prosthesis undergoing complex motion are not well understood. Therefore, examining complex motion may provide an improved understanding of the post-operative behavior of spinal implants. (2) Methods: The aim of this study was to develop kinematic tests that simulate multiplanar motion and combined rotational–translational motion in a disc prosthesis. In this context, five generic zirconia-toughened alumina (BIOLOX®delta, CeramTec, Germany) ball and socket samples were tested in a 6 DOF spine simulator under displacement control with an axial compressive force of 100 N in five motion modes: (1) flexion–extension (FE = ± 7.5°), (2) lateral bending (LB = ± 6°), (3) combined FE-LB (4) combined FE and anteroposterior translation (AP = 3 mm), and (5) combined LB and lateral motion (3 mm). For combined rotational–translational motion, two scenarios were analyzed: excessive translational movement after sample rotation (scenario 1) and excessive translational movement during rotation (scenario 2). (3) Results: For combined FE-LB, the resultant forces and moments were higher compared to the unidirectional motion modes. For combined rotational–translational motion (scenario 1), subluxation occurred at FE = 7.5° with an incremental increase in AP translation = 1.49 ± 0.18 mm, and LB = 6° with an incremental increase of lateral translation = 2.22 ± 0.16 mm. At the subluxation point, the incremental increase in AP force and lateral force were 30.4 ± 3.14 N and 40.8 ± 2.56 N in FE and LB, respectively, compared to the forces at the same angles during unidirectional motion. For scenario 2, subluxation occurred at FE = 4.93° with an incremental increase in AP translation = 1.75 mm, and LB = 4.52° with an incremental increase in lateral translation = 1.99 mm. At the subluxation point, the incremental increase in AP force and lateral force were 39.17 N and 38.94 N in FE and LB, respectively, compared to the forces in the same angles during the unidirectional motion. (4) Conclusions: The new test protocols improved the understanding of in vivo-like behavior from in vitro testing. Simultaneous translation–rotation motion was shown to provoke subluxation at lower motion extents. Following further validation of the proposed complex motion testing, these new methods can be applied future development and characterization of spinal motion-preserving implants. [ABSTRACT FROM AUTHOR]

Background: Without clear signs of infection, spinal implant failure is attributed to mechanical overloads and aseptic loosening. However, how low-grade infections contribute to seemingly aseptic implant failure is unclear. Purpose: The systematic review examined unexpected positive cultures (UPCs) in revision spine surgery regarding prevalence, isolated pathogens, risk factors, and strategies to reduce infection among asymptomatic patients undergoing revision spine surgery. Methods: We followed the PRISMA guidelines and searched four main databases (PubMed, EMBASE, SCOPUS, Web of Science) comprehensively until January 2023 for articles reporting UPC after presumed aseptic adult revision spine surgery. The UPC rates were pooled, and risk factors were compared with the culture-negative control group and represented as odds ratio (OR) or mean difference (MD). Results: Fifteen studies of 1057 individuals were included in two groups: culture-positive or UPCs (n = 317) and culture-negative or control (n = 740). The overall UPC prevalence was 33.2% (317/1057, range: 0 to 53%, 95% CI = 30.2%–36.4%), and Cutibacterium acnes (43.0%, 95% CI = 37.4%–48.8%), Coagulase-negative Staphylococci (CoNS), (39.5%, 95% CI = 33.2%–46.2%), and Staphylococcus species in general (49.5%, 95%CI = 43.7%–55.4%) were reported the most common isolated microbes. 16.1% of the UPCs were polymicrobial. Risk factors associated with UPC rates were female sex (OR = 2.62, 95%CI = 1.76–3.90, P < 0.001), screw loosening (OR = 4.43, 95%CI = 1.31–15.02, P = 0.02), number of operated levels (MD = 0.77, 95%CI = 0.33–1.22, P = 0.0007), and shorter time since index surgery (MD = − 8.57 months, 95%CI = − 14.76, -2.39, P = 0.02). Conclusions: One-third of patients undergoing spine revision surgery revealed UPC in this study. Each UPC pathogen interpretation and antibiotic use decision should be interpreted case by case. Level of evidence: IV. [ABSTRACT FROM AUTHOR]

To investigate the wear and corrosion of titanium alloy spinal implants in vivo, we evaluated removed implants and their surrounding scar tissues from 27 patients between May 2019 and April 2021. We performed scanning electron microscopy, energy-dispersive X-ray spectroscopy, and histological analysis. The results revealed metal-like particles in the soft tissues of seven patients, without any considerable increase in inflammatory cell infiltration. Patients with fractures showed lower percentages of wear and corrosion compared with other patients (42% and 17% vs. 59% and 26%). Polyaxial screws exhibited higher wear and corrosion percentages (53% and 23%) compared with uniaxial screws (39% and 3%), although in patients with fracture, the reverse was observed (20% and 0% vs. 39% and 3%). We found that titanium alloy spinal implants experience some degree of wear and corrosion in vivo. The titanium alloy particles formed by wear exhibited good histocompatibility, not causing inflammation, foreign body reactions, or osteolysis. Therefore, spinal implants should be removed cautiously when treating titanium alloy spinal metallosis. The wear and corrosion of the implants increase with the increase in implantation time, although the screw structure does not significantly affect these changes. [ABSTRACT FROM AUTHOR]

Objective: Despite the successful application of spinal instrumentation surgery, the development of surgical site infections (SSIs) remains inevitable even in the most experienced neurosurgery clinics. The aim of this study was to analyze potential risk factors, reassess diagnosis and treatment, and discuss outcomes in line with the literature. Materials and Methods: The records of 1564 patients who underwent spinal instrumentation surgery between 2016 and 2023 were retrospectively reviewed. Among these patients, 297 developed superficial or deep SSIs in the postoperative period. Diagnosis was based on postoperative positive wound cultures, intraoperative cultures, serum procalcitonin and C-reactive protein (CRP) levels measured in the postoperative period, and gadolinium-enhanced magnetic resonance imaging (MRI) and computed tomography scan. Demographic characteristics and preoperative risk factors of the patients were analyzed. Results: SSIs were observed in 297 (18.9%) out of 1564 patients who underwent spinal instrumentation surgery. Multiple risk factors for spinal infections following spinal instrumentation surgery, which can manifest in both the early and delayed postoperative periods, were identified. Early diagnosis and prompt initiation of appropriate treatment were associated with better prognosis in 215 patients. Among the 82 patients diagnosed late, all underwent revision surgery for spinal implant removal due to failed medical treatment, with clinical outcomes in 23 of these patients not meeting post-operative expectations. The relationship between early and delayed diagnosis and the need for reoperation were statistically significant (p<0.001). Reoperation was required in 92.7% of patients with delayed diagnosis compared with 15.3% of patients with early diagnosis, indicating an approximately 11.6-fold higher risk of reoperation in patients with delayed diagnosis. Conclusion: Intraoperative culture results are the gold standard for diagnosing SSIs after spinal instrumentation surgery and are also valuable for selecting antimicrobial agents. Monitoring procalcitonin and CRP levels, along with MRI, is highly beneficial for diagnosis. Early detection requires fewer surgical interventions and improves clinical outcomes. [ABSTRACT FROM AUTHOR]

• Serum concentrations of metal ions, notably titanium, were markedly higher in the spinal fusion surgery group compared to the control group. • The percentage of patients with metal concentrations exceeding normal ranges was significantly greater in the surgery cohort versus controls. • Mean chromium elevations in the surgical group were approximately 24-fold higher than levels in healthy subjects. • Future studies require standardized methodology in areas including patient age ranges, definitions of elevated metal levels, separated versus pooled data groups, and complete reporting of numerical data. Elevated blood metal levels have been reported in patients after spinal surgery using metallic implants. Although some studies have suggested an association between heightened blood metal concentrations and potential adverse effects, estimates of the incidence of abnormal metal levels after spinal surgery have been inconsistent. The aims of this systematic review and meta-analysis were to assess: (1) mean differences in blood metal ion levels between patients undergoing spinal fusion surgery and healthy controls, (2) odds of elevated blood metal ion levels after surgery compared to presurgery levels, and (3) pooled incidence of elevated blood metal ions overall and by metal type. Systematic review and meta-analysis. The patient sample included 613 patients from 11 studies who underwent spinal surgery instrumentation. Blood metal ion concentrations and the incidence of patients with elevated metal levels compared with in those the control group. A comprehensive search was conducted in PubMed, EMBASE, Scopus, and Cochrane Library to identify studies reporting blood metal ion levels after spinal fusion surgery. Mean differences (MD), odds ratios (OR), and incidence rates were pooled using random effects models. Heterogeneity was assessed using I2 statistics, and fixed-effects models were used if no heterogeneity was detected. Detailed statistical analysis was performed using the Review Manager version 5.4 software. The analysis included 11 studies, with a total of 613 patients. Mean blood metal ion levels were significantly higher after spinal fusion surgery (MD 0.56, 95% CI 0.17–0.96; I2=86%). Specifically, titanium levels were significantly elevated (MD 0.81, 95% CI 0.32–1.30; I2=47%). The odds of elevated blood metal ions were higher after surgery (OR 8.17, 95% CI 3.38–19.72; I2=41%), primarily driven by chromium (OR 23.50, 95% CI 5.56–99.31; I2=30%). The incidence of elevated chromium levels was found to be 66.98% (95% CI 42.31–91.65). In conclusion, blood metal ion levels, particularly titanium and chromium, were significantly increased after spinal fusion surgery compared to presurgery levels and healthy controls. Approximately 70% of the patients exhibited elevated blood levels of chromium and titanium. [ABSTRACT FROM AUTHOR]

Background Osteotomies allow the restoration of appropriate sagittal alignment; however, closure of osteotomies can be challenging. Typical closure involves compressing pedicle screw heads across the rods, potentially causing screw loosening and failure. Motorized hinged operating tables are often used to assist with controlled closure of osteotomies without manual compression, but there is no published research quantifying the amount of correction provided solely by changes in the table angle. Question/purpose What is the incremental amount of correction achieved by change in the table angle versus instrumented manipulation during osteotomy closure in transforaminal lumbar interbody fusion (TLIF) with Smith-Petersen osteotomy? Methods Sixty-one patients undergoing Smith-Peterson osteotomy and bilateral TLIF using a motorized hinged table from October 2019 to March 2022 were prospectively enrolled. Two patients did not undergo surgery, two did not have table extension, and seven did not have data collected intraoperatively because of disruptions in research protocols owing to the coronavirus-19 pandemic. Fifty patients (24 male, 26 female) who underwent a total of 73 osteotomies were included in the final analysis. The mean ± standard deviation age was 61 ± 11 years, and the mean BMI was 31 ± 6 kg/m². Patients were positioned prone on the table and flexed to 10° for decompression, Smith-Petersen osteotomy, and TLIF. The table was then extended in 5° increments, and radiographs were taken until 10° of extension was achieved or the osteotomy was fully closed. Changes in segmental lordosis across the operative site for each 5° increment were measured to the nearest degree by two reviewers. Intraclass correlation coefficients for segmental lordosis measurements at each table angle change were calculated as 0.97 to 0.98, with all p values < 0.001, indicating excellent agreement. Results Table change from 10° to 5° yielded a mean segmental lordosis change of 1.9° ± 1.5° (73 osteotomies), 5° to 0° yielded a change of 1.3° ± 0.9° (73 osteotomies), 0° to -5° yielded a change of 1.3° ± 1.0° (69 osteotomies), and -5° to -10° yielded a change of 1.1° ± 1.3° (61 osteotomies). Rod placement and compression yielded a mean 1.8° ± 2.0° of additional segmental lordosis. Conclusion Using a motorized hinged table facilitated an average of 5.6° of total segmental lordosis correction during controlled Smith-Peterson osteotomy closure without the need for cantilevering forces across spinal instrumentation. Surgeons can use this technique to reduce the compression forces needed to close osteotomies, which could eliminate a potential source of complications. [ABSTRACT FROM AUTHOR]

Study Design: Narrative Review. Objective: Metastatic spine tumour surgery (MSTS) is an important treatment modality of metastatic spinal disease (MSD). Increase in MSTS has been due to improvements in our oncological treatment, as patients have increased longevity and even those with poorer comorbidities are now being considered for surgery. However, there is currently no guideline on how MSTS surgeons should select the appropriate levels to instrument, and which type of implants should be utilised. Methods: The current literature on MSTS was reviewed to study implant and construct decision making factors, with a view to write this narrative review. All studies that were related to instrumentation in MSTS were included. Results: A total of 58 studies were included in this review. We discuss novel decision-making models that should be taken into account when planning for surgery in patients undergoing MSTS. These factors include the quality of bone for instrumentation, the extent of the construct required for MSTS patients, the use of cement augmentation and the choice of implant. Various studies have advocated for the use of these modalities and demonstrated better outcomes in MSTS patients when used appropriately. Conclusion: We have established a new instrumentation algorithm that should be taken into consideration for patients undergoing MSTS. It serves as an important guide for surgeons treating MSTS, with the continuous evolvement of our treatment capacity in MSD. Level of Evidence IV. [ABSTRACT FROM AUTHOR]

Expandable devices such as interbody cages, vertebral body reconstruction cages, and intravertebral body expansion devices are frequently utilized in spine surgery. Since the introduction of expandable implants in the early 2000s, the variety of mechanisms that drive expansion and implant materials have steadily increased. By examining expandable devices that have achieved commercial success and exploring emerging innovations, we aim to offer an in-depth evaluation of the different types of expandable cages used in spine surgery and the underlying mechanisms that drive their functionality. We performed a review of expandable spinal implants and devices by querying the National Library of Medicine MEDLINE database and Google Patents database from 1933 to 2024. Five major types of mechanical jacks that drive expansion were identified: scissor, pneumatic, screw, ratchet, and insertion-expansion. We identified a trend of screw jack mechanism being the predominant machinery in vertebral body reconstruction cages and scissor jack mechanism predominating in interbody cages. Pneumatic jacks were most commonly found in kyphoplasty devices. Critically reviewing the mechanisms of expansion and identifying trends among effective and successful cages allows both surgeons and medical device companies to properly identify future areas of development. [ABSTRACT FROM AUTHOR]

Background: Modern surgical techniques allow for the correction of spinal deformity, stopping its progression and improving pain relief and social and physical functioning. These instruments have different implant designs, screws, and rod diameters and can be composed of different metal alloys with different hardnesses, which can have a significant impact on the effect of correcting spinal deformities. We designed a retrospective cohort study based on the same surgical technique and spine system using different implant sizes, and compared the results across them. Methods: This is a retrospective review of adolescent idiopathic scoliosis (AIS) patients who underwent posterior spinal fusion (PSF) between 2016 and 2022 with a minimum two-year follow-up (FU) using two spinal implant systems: 5.5 and 6.0 mm diameter screws with double 5.5 mm titanium rods (Group 1 (G1)), and 6.0 and 6.5 mm diameter pedicle screws with double 6.0 mm cobalt–chromium rods (Group 2 (G2)). The evaluated data were as follows: preoperative personal data, radiographic outcomes, complications, and health-related quality of life questionnaire (HRQoL). The parameters were reviewed preoperatively, after the final fusion, and during the FU. Results: The mean age of all 260 patients at surgery was 14.8 years. The average BMI was also similar in both groups and was noted as 21. The mean levels of fusion and screw density were similar in both groups. The mean preoperative major curves (MCs) were 57.6° and 62.5° in G1 and G2, respectively. The mean flexibility of the curves was noted as 35% in G1 and 33% in G2. After definitive surgery, the mean percentage correction of the MC was better in G2 vs. G1, with 74.5% vs. 69.8%, respectively (p < 0.001). At the final FU, the average loss of correction was 5.9° for G1 and 3.2° for G2 (p < 0.001). The mean preoperative (TK) thoracic kyphosis (T2–T5) was 12.2° in G1 and 10.8° in G2. It was corrected to 15.2° in G1 and to 13° in G2. At the FFU, we noted a significant difference in the TK (T2–T5) between the groups, with 16.7° vs. 9.6° for G1 vs. G2, respectively (p < 0.001). Statistical significance was observed between the preoperative sagittal balance and the final follow-up for both groups (p < 0.001). Conclusions: AIS patients surgically treated with screws with a larger diameter and thicker and stiffer rods showed greater correction and postoperative thoracic kyphosis without implant failure. The complication rates, implant density, and clinical outcomes remained similar. The radiographic benefits reported in this cohort study suggest that large-sized screws and stiffer rods for the correction of pediatric spinal deformities are safe and very effective. [ABSTRACT FROM AUTHOR]

Study Design. Retrospective case series. Objective. To characterize failure rates of cervical cages based on manufacturer and design characteristics using the nationwide database of reported malfunctions. Background. The Food and Drug Administration (FDA) aims to ensure the safety and efficacy of cervical interbody implants postimplantation; however, intraoperative malfunctions may be overlooked. Materials and Methods. The FDA's Manufacturer and User Facility Device Experience database was queried for reports of cervical cage device malfunctions from 2012 to 2021. Each report was categorized based on the failure type, implant design, and manufacturer. Two market analyses were performed. First, "failure-to-market share indices" were generated by dividing the number of failures per year for each implant material by its yearly US market share in cervical spine fusion. Second, "failure-to-revenue indices" were calculated by dividing the total number of failures per year for each manufacturer by their approximate yearly revenue from spinal implants in the US. Outlier analysis was performed to generate a threshold value above which failure rates were defined as greater than the normal index. Results. In total, 1336 entries were identified, and 1225 met the inclusion criteria. Of these, 354 (28.9%) were cage breakages, 54 (4.4%) were cage migrations, 321 (26.2%) were instrumentationrelated failures, 301 (24.6%) were assembly failures, and 195 (15.9%) were screw failures. Poly-ether-ether-ketone implants had higher failure by market share indices for both migration and breakage compared with titanium. Upon manufacturer market analysis, Seaspine, Zimmer-Biomet, K2M, and LDR exceeded the failure threshold. Conclusion. The most common cause of implant malfunction was breakage. Poly-ether-ether-ketone cages were more likely to break and migrate compared with titanium ones. Many of these implant failures occurred intraoperatively during instrumentation, which underscores the need for FDA evaluation of these implants and their accompanying instrumentation under the appropriate loading conditions before commercial approval. [ABSTRACT FROM AUTHOR]

The increasing use of medical implants in various areas of medicine, particularly in orthopedic surgery, oncology, cardiology and dentistry, displayed the limitations in long-term integration of available biomaterials. The effective functioning and successful integration of implants requires not only technical excellence of materials but also consideration of the dynamics of biomaterial interaction with the immune system throughout the entire duration of implant use. The acute as well as long-term decisions about the efficiency of implant integration are done by local resident tissue macrophages and monocytederived macrophages that start to be recruited during tissue damage, when implant is installed, and are continuously recruited during the healing phase. Our review summarized the knowledge about the currently used macrophagesbased in vitro cells system that include murine and human cells lines and primary ex vivo differentiated macrophages. We provided the information about most frequently examined biomarkers for acute inflammation, chronic inflammation, foreign body response and fibrosis, indicating the benefits and limitations of the model systems. Particular attention is given to the scavenging function of macrophages that controls dynamic composition of peri-implant microenvironment and ensures timely clearance of microorganisms, cytokines, metabolites, extracellular matrix components, dying cells as well as implant debris. We outline the perspective for the application of 3D systems for modelling implant interaction with the immune system in human tissuespecific microenvironment avoiding animal experimentation. [ABSTRACT FROM AUTHOR]

Lumbar interbody fusion (LIF) is a common surgical procedure, but postoperative complications, such as osteolytic vertebral endplate cysts, can adversely affect patient outcomes. This study aims to investigate whether tritanium cages (Stryker, Mahwah, New Jersey, USA) are effective in preventing osteolytic vertebral endplate cysts after LIF. Clinical data from 8 years (2013–2020) of LIF procedures at our hospital were analyzed. Computed tomography was used to assess the formation of osteolytic vertebral endplate cysts 6 months after surgery. Clinical factors potentially associated with cyst formation were compared among 3 different interbody spacer materials: tritanium, titanium, and polyetheretherketone. LIF was performed for 169 patients at 205 spinal levels, employing tritanium cages in 56 levels (48 patients), titanium in 103 levels (86 patients), and polyetheretherketone in 46 levels (35 patients). At 6 months after LIF, 27.3% of patients showed worsening of osteolytic vertebral endplate cysts. Multivariate logistic regression analysis showed that tritanium cages (odds ratio [OR], 3.86; 95% confidence interval [CI], 1.46–10.21) and titanium (OR, 2.55; 95% CI, 1.13–5.75), and posterior LIF (OR, 5.74; 95% CI, 2.24–14.74) were associated with a reduced risk of postoperative osteolytic vertebral endplate cysts. Tritanium cages have shown promise in preventing postoperative osteolytic vertebral endplate cysts, suggesting their potential as a stable and effective choice in LIF procedures. These findings have significant implications for improving patient outcomes and warrant further investigation to optimize surgical techniques and materials. [ABSTRACT FROM AUTHOR]

Objective: To compare the image quality of low-dose CT (LD-CT) with tin filtration of the lumbar spine after metal implants to standard clinical CT, and to evaluate the potential for metal artifact and dose reduction. Materials and methods: CT protocols were optimized in a cadaver torso. Seventy-four prospectively included patients with metallic lumbar implants were scanned with both standard CT (120 kV) and tin-filtered LD-CT (Sn140kV). CT dose parameters and qualitative measures (1 = worst,4 = best) were compared. Quantitative measures included noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and the width and attenuation of the most prominent hypodense metal artifact. Standard CT and LD-CT were assessed for imaging findings. Results: Tin-filtered LD-CT was performed with 60% dose saving compared to standard CT (median effective dose 3.22 mSv (quartile 1–3: 2.73–3.49 mSv) versus 8.02 mSv (6.42–9.27 mSv; p <.001). Image quality of CT and tin-filtered low-dose CT was good with excellent depiction of anatomy, while image noise was lower for CT and artifacts were weaker for tin-filtered LD-CT. Quantitative measures also revealed increased noise for tin-filtered low-dose CT (41.5HU), lower SNR (2) and CNR (0.6) compared to CT (32HU,3.55,1.03, respectively) (all p <.001). However, tin-filtered LD-CT performed superior regarding the width and attenuation of hypodense metal artifacts (2.9 mm and -767.5HU for LD-CT vs. 4.1 mm and -937HU for CT; all p <.001). No difference between methods was observed in detection of imaging findings. Conclusion: Tin-filtered LD-CT with 60% dose saving performs comparable to standard CT in detection of pathology and surgery related complications after lumbar spinal instrumentation, and shows superior metal artifact reduction. [ABSTRACT FROM AUTHOR]

Purpose: Short-segment minimally invasive percutaneous spinal osteosynthesis has now become one of the treatments of choice to treat thoracolumbar fractures. The question of implant removal once the fracture has healed is still a matter of debate since this procedure can be associated with loss of sagittal correction. Therefore, we analyzed risk factors for kyphosis recurrence after spinal implants removal in patients treated with short-segment minimally invasive percutaneous spinal instrumentation for a thoracolumbar fracture. Methods: A total of 32 patients who underwent implant removal in percutaneous osteosynthesis for post-traumatic thoracolumbar fracture were enrolled in our study. Patient's medical record, operative report and imaging examinations carried out at the trauma and during the follow-up were analyzed. Results: Every patient experienced fracture union. Vertebral kyphotic angle (VKA) and Cobb angle (CA) improved significantly after stabilization surgery. VKA, CA, upper disk kyphotic angle (UDKA) and lower disk kyphotic angle (LDKA) significantly gradually decreased during follow-up. Traumatic disk injury (p: 0.001), younger age (p: 0.01), canal compromise (p: 0.04) and importance of surgical correction (p < 0.001) were significantly associated with kyphosis recurrence after implant removal. Anterior body augmentation did not affect loss of correction (CA and VKA) during the follow-up period (p: 0.57). Conclusion: Despite correction of the fracture after stabilization, we observed a progressive loss of correction over time appearing even before implant removal. Particular attention should be paid to post-traumatic disk damage or canal invasion, to young patients and to surgical overcorrection of the traumatic kyphosis. [ABSTRACT FROM AUTHOR]

Purpose: To develop and validate a deep-learning-based algorithm (DLA) that is designed to segment and classify metallic objects in topograms of abdominal and spinal CT. Methods: DLA training for implant segmentation and classification was based on a U-net-like architecture with 263 annotated hip implant topograms and 2127 annotated spine implant topograms. The trained DLA was validated with internal and external datasets. Two radiologists independently reviewed the external dataset consisting of 2178 abdomen anteroposterior (AP) topograms and 515 spine AP and lateral topograms, all collected in a consecutive manner. Sensitivity and specificity were calculated per pixel row and per patient. Pairwise intersection over union (IoU) was also calculated between the DLA and the two radiologists. Results: The performance parameters of the DLA were consistently >95% in internal validation per pixel row and per patient. DLA can save 27.4% of reconstruction time on average in patients with metallic implants compared to the existing iMAR. The sensitivity and specificity of the DLA during external validation were greater than 90% for the detection of spine implants on three different topograms and for the detection of hip implants on abdominal AP and spinal AP topograms. The IoU was greater than 0.9 between the DLA and the radiologists. However, the DLA training could not be performed for hip implants on spine lateral topograms. Conclusions: A prototype DLA to detect metallic implants of the spine and hip on abdominal and spinal CT topograms improves the scan workflow with good performance for both spine and hip implants. [ABSTRACT FROM AUTHOR]

Methods to improve osseointegration of orthopedic spinal implants remains a clinical challenge. Materials composed of poly-ether-ether-ketone (PEEK) and titanium are commonly used in orthopedic applications due to their inherent properties of biocompatibility. Titanium has a clinical reputation for durability and osseous affinity, and PEEK offers advantages of a modulus that approximates osseous structures and is radiolucent. The hypothesis for the current investigation was that a titanium plasma spray (TPS) coating may increase the rate and magnitude of circumferential and appositional trabecular osseointegration of PEEK and titanium implants versus uncoated controls. Using an in vivo ovine model, the current investigation compared titanium plasma-sprayed PEEK and titanium dowels versus nonplasma-sprayed dowels. Using a time course study of 6 and 12 weeks postoperatively, experimental assays to quantify osseointegration included micro-computed tomography (microCT), biomechanical testing, and histomorphometry. In-vivo ovine model. Twelve skeletally mature crossbred sheep were equally randomized into postoperative periods of 6 and 12 weeks. Four types of dowel implants–PEEK, titanium plasma-sprayed PEEK (TPS PEEK), titanium, and titanium plasma-sprayed titanium (TPS titanium) were implanted into cylindrical metaphyseal defects in the distal femurs and proximal humeri (one defect per limb, n=48 sites). Sixteen nonoperative specimens (eight femurs and eight humeri) served as zero time-point controls. Half of the specimens underwent destructive biomechanical pullout testing and the remaining half quantitative microCT to quantify circumferential bone volume within 1 mm and 2 mm of the implant surface and histomorphometry to compute direct trabecular apposition. There were no intra- or perioperative complications. The TPS-coated implants demonstrated significantly higher peak loads at dowel pullout at 6 and 12 weeks compared with uncoated controls (p<.05). No differences were observed across dowel treatments at the zero time-point (p>.05). MicroCT results exhibited no significant differences in circumferential osseointegration between implants within 1 mm or 2 mm of the dowel surface (p>.05). Direct appositional osseointegration of trabecular bone based on histomorphometry was higher for TPS-coated groups, regardless of base material, compared with uncoated treatments at both time intervals (p<.05). The current in vivo study demonstrated the biological and mechanical advantages of plasma spray coatings. TPS improved histological incorporation and peak force required for implant extraction. Plasma spray coatings may offer clinical benefit by improving biological fixation and osseointegration within the first 6 to 12 weeks postoperatively- the critical healing period for implant-based arthrodesis procedures. [ABSTRACT FROM AUTHOR]

Background: Adolescent idiopathic scoliosis (AIS) is a spinal pathology affecting 0.47–5.2% of the population, often requiring surgical intervention to control deformity progression. Posterior spinal instrumentation and fusion with pedicle screw fixation are standard procedures for AIS curve correction; however, implant failure remains a significant complication, especially in multi-level fusions. This retrospective cohort study aims to compare the failure rates between conventional pedicle screws (CPSs) and fenestrated pedicle screws (FPSs) in AIS treatment, with a focus on investigating potential causes of these failures. Methods: This study, conducted from January 2016 to December 2020, involves a two-center retrospective analysis of AIS patients undergoing posterior instrumented fusion. Results: Data from a total of 162 patients (122 females and 40 males) revealed a mean age of 14.95 years (range: 11–18). The CPS group consisted of 80 patients (56 females and 24 males), whereas the FPS group consisted of 82 patients (66 females and 16 males) stratified by Risser grade and Lenke Classification. Radiological assessments, clinical outcomes, and SRS-22 scores were evaluated pre-operatively, at 6 months, and post-operatively (minimum follow-up of 2 years). Conclusions: Fenestrated pedicle screws (FPSs) pose concerns due to their lower mechanical strength compared to solid screws. Understanding their limitations and optimizing their application in AIS treatment is essential. [ABSTRACT FROM AUTHOR]

Introduction: A practical solution to the incidental unreliability of intraoperative neuromonitoring (IONM) may be the simultaneous neurophysiological recording and control of the surgical field through a camera (the concept of "Real-time" IONM). During "Real-time" IONM, the surgeon is immediately warned about the possibility of damage to the neural structures during, but not after, standard idiopathic scoliosis (IS) corrective surgery procedures (the concept of "Surgeon–neurophysiologist" interactive, verbal IONM). This study aimed to compare the advantages, utilities, reliabilities, and time consumption of the two IONM scenarios. Methods: Studies were performed in two similar groups of patients undergoing surgery primarily due to Lenke 2 idiopathic scoliosis (N = 120), when both IONM approaches were applied. Neurophysiological evaluations of the spinal transmission were performed pre- (T0), intra- (before (T1) and after (T2) surgery), and postoperatively (T3), as well as once in healthy volunteers (control, N = 60). Non-invasive and innovative recordings of the motor evoked potentials (MEPs) bilaterally from the peroneal (PER) nerve and tibialis anterior (TA) muscle were performed with surface electrodes as a result of transcranial magnetic stimulation (TMS) or electrical stimulation (TES) at T0–T3. Results: In both groups, the MEP amplitudes and latencies recorded from the PER nerve were approximately 67% lower and 3.1 ms shorter than those recorded from the TA muscle. The MEP recording parameters differed similarly at T0–T3 compared to the control group. In all patients, the MEP parameters induced by TMS (T0) and TES (T1) did not differ. The MEP amplitude parameters recorded from the TA and PER at T1 and T2 indicated a bilateral improvement in the neural spinal conduction due to the surgical intervention. The TMS-induced MEP amplitude at T3 further increased bilaterally. In both IONM groups, an average 51.8 BIS level of anesthesia did not affect the variability in the MEP amplitude, especially in the PER recordings when the applied TES strength was 98.2 mA. The number of fluctuations in the MEP parameters was closely related to the number of warnings from the neurophysiologist during the transpedicular screw implantation, corrective rod implantation, and distraction, derotation, and compression procedures, and it was higher in the "Surgeon–neurophysiologist" IONM group. The average duration of surgery was shorter by approximately one hour in the "Real-time" IONM group. The number of two-way communications between the surgeon and the neurophysiologist and vice versa in the "Real-time" IONM group decreased by approximately half. Conclusions: This study proves the superiority of using "Real-time" IONM over the standard "Surgeon–neurophysiologist" IONM procedure in increasing the safety and non-invasiveness, shortening the time, and lowering the costs of the surgical treatment of IS patients. The modifications of the MEP nerve-conduction-recording technology with surface electrodes from nerves enable precise and reliable information on the pediatric patient's neurological condition at every stage of the applied surgical procedures, even under conditions of slight fluctuations in anesthesia. [ABSTRACT FROM AUTHOR]

Background: Adult spinal deformities (ASD) present complex challenges in spine surgery. The diverse nature of these deformities requires a comprehensive understanding of their classification and treatment options. Traditional approaches, such as fusion and rigid stabilization are associated with complications, including screw loosening, breakage, proximal junctional kyphosis (PJK), and pseudoarthrosis. Dynamic stabilization techniques have emerged as promising alternatives, to reduce these complications and preserve spinal motion. Objective: This study investigated the effectiveness of dynamic stabilization using the Dynesys system in the surgical treatment of adult degenerative spinal deformities, with a particular emphasis on their classification. Methods: ASDs were classified according to the Berjano–Lamartina (BL) and Silva–Lenke (SL) classifications. We analyzed the efficacy of the Dynesys system in enhancing sagittal balance, radiological parameters, and clinical outcomes in this context. Results: Dynamic stabilization of patients with ASDs using the Dynesys system significantly improved the visual analog scale and Oswestry Disability Index scores and decreased the complication rates. Patients with BL types 2, 3, and 4 experienced a significant improvement in sagittal balance followed by sagittal vertical axis measurements (p = 0.045, p = 0.015, and p < 0.0001, respectively). Conclusion: The SL and BL classifications, which were originally developed for rigid spinal stabilization, can be applied in dynamic stabilization. Furthermore, dynamic stabilization using the Dynesys system can be used as an alternative to rigid stabilization in SL levels 2 and 3, and BL types 1, 2, and 3, and in some patients with type 4 ASDs. [ABSTRACT FROM AUTHOR]

Study design: Clinical observational study. Objective: The ROTAIO® cervical disc prosthesis is a novel unconstrained implant with a variable center of rotation aiming at physiological motion. The objective of this multicenter prospective trial was to evaluate clinical outcome and complications within 2 years. Material and Methods: 120 patients (72 females and 48 males with median age of 43.0 years [23-60 yrs] underwent ACDA (ROTAIO®, SIGNUS Medical, Alzenau, Germany) and were prospectively followed for 24 months. Preoperative complaints were mainly associated with radiculopathy (n = 104) or myelopathy (n=16). There were 108 monosegmental and 12 bisegmental procedures including 6 hybrid constructs. Clinical outcome was evaluated at 3, 12 and 24 months in 100%, 96% and 77% of the cohort by VAS, NDI, WL-26, Patient's Satisfaction Index (PSI), SF-36, Nurick Score, mJOA, Composite Success Rate, complications, patient's overall satisfaction and analgesics use. Results: Highly significant clinical improvements were observed according to NDI and VAS (P <.0001 (arm); P <.001 (neck); P =.002 (head)) at all time points. Analgetic use could be reduced in 87.1 to 95.2%. Doctor's visits have been reduced in 93.8% after 24 months. Patient's overall satisfaction was high with 78.4 to 83.5% of patients. The composite success rate was 77.5% after 12 months and 76.9% after 24 months. There were no major complications in this series. Slight subsidence of the prosthesis was observed in 2 patients and 3 patients demonstrated fusion after 24 months. 2 patients developed symptomatic foraminal stenosis, so that implant removal and fusion was performed resulting in a revision rate of 1.7% in 2 years. Conclusion: The ROTAIO® cervical disc prosthesis is a safe and efficient treatment option for symptomatic degenerative disc disease demonstrating highly significant clinical improvement and high patient's overall satisfaction with very low revision rates at 2 years. [ABSTRACT FROM AUTHOR]

Propose: This meta-analysis aimed to determine whether 3D-printed artificial vertebral bodies (AVBs) have superior clinical efficacy compared to conventional titanium mesh cages (TMCs) for spinal reconstruction after total en bloc spondylectomy (TES) for spinal tumors. Methods: Electronic databases, including PubMed, OVID, ScienceDirect, Embase, CINAHL, Web of Science, Cochrane Library, WANFANG, and CNKI, were searched to identify clinical trials investigating 3D-printed AVB versus conventional TMC from inception to August 2023. Data on the operation time, intraoperative blood loss, preoperative and postoperative visual analogue scale (VAS) scores, preoperative and postoperative Frankel classification of spinal cord injury, vertebral body subsidence, and early complications were collected from eligible studies for a meta-analysis. Data were analyzed using Review Manager 5.4 and Stata 14.0. Results: Nine studies assessing 374 patients were included. The results revealed significant differences between the 3D-printed AVB and conventional TMC groups with regard to operation time (P = 0.04), intraoperative blood loss (P = 0.004), postoperative VAS score (P = 0.02), vertebral body subsidence (P < 0.0001), and early complications (P = 0.02). Conversely, the remaining preoperative VAS score and Frankel classifications (pre-and postoperative) did not differ significantly between the groups. Conclusion: The 3D-printed AVB in spinal reconstruction after TES for spinal tumors has the advantages of a short operative time, little intraoperative blood loss, weak postoperative pain, low occurrence of vertebral body subsidence and early complications, and a significant curative effect. This could provide a strong basis for physicians to make clinical decisions. [ABSTRACT FROM AUTHOR]

This systematic review summarizes existing evidence and outlines the benefits of artificial intelligence-assisted spine surgery. The popularity of artificial intelligence has grown significantly, demonstrating its benefits in computer-assisted surgery and advancements in spinal treatment. This study adhered to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses), a set of reporting guidelines specifically designed for systematic reviews and meta-analyses. The search strategy used Medical Subject Headings (MeSH) terms, including "MeSH (Artificial intelligence)," "Spine" AND "Spinal" filters, in the last 10 years, and English--from January 1, 2013, to October 31, 2023. In total, 442 articles fulfilled the first screening criteria. A detailed analysis of those articles identified 220 that matched the criteria, of which 11 were considered appropriate for this analysis after applying the complete inclusion and exclusion criteria. In total, 11 studies met the eligibility criteria. Analysis of these studies revealed the types of artificial intelligence-assisted spine surgery. No evidence suggests the superiority of assisted spine surgery with or without artificial intelligence in terms of outcomes. In terms of feasibility, accuracy, safety, and facilitating lower patient radiation exposure compared with standard fluoroscopic guidance, artificial intelligence-assisted spine surgery produced satisfactory and superior outcomes. The incorporation of artificial intelligence with augmented and virtual reality appears promising, with the potential to enhance surgeon proficiency and overall surgical safety. [ABSTRACT FROM AUTHOR]

Lateral lumbar interbody fusion (LLIF) is a popular technique as it allows for the placement of a large interbody implant through a retroperitoneal, transpsoas working corridor. Historically, the interbody is placed with the patient in lateral decubitus and then repositioned to prone for the posterior instrumentation. While this has been an effective and successful technique, removing the interoperative flip would improve the efficiency of these cases. This has led to modified LLIF approaches including single-position prone LLIF (pLLIF). This modification has shown to be an efficient and powerful technique; however, learning to navigate the LLIF approach in the prone position has its own challenges. The purpose of this article is to provide a detailed description of our pLLIF technique while simultaneously introducing surgical tips to overcome the challenges of the approach and optimize the implantation of the interbody device. Novel Techniques & Technology. [ABSTRACT FROM AUTHOR]

Introduction: Psychological evaluation is required by insurance companies in the United States prior to proceeding with a spinal cord stimulation or a dorsal root ganglion stimulation trial. Since January 2017, we implemented a Multidisciplinary Team Conference for Neuromodulation in our center to facilitate the collaboration between pain physicians and psychologists and to optimize screening of neuromodulation candidates. This study aims to report the impact of this team conference on improvement of neuromodulation outcome in our center. Methods: Appropriateness of neuromodulation were discussed in the team conference after initial visit with the pain specialist and psychological evaluation. For this study, we prospectively and retrospectively collected data on neuromodulation candidates who went through the team conference and those who did not as controls. Results: We discussed 461 patients in the team conference sessions from January 2017 to July 2023. Out of these, a spinal cord stimulator or a dorsal root ganglion stimulator trial was performed in 164 patients with 80.5% (132 cases) trial success rate leading to 140 implants. Out of these implants, 26 (18.6%) explanted and 21 (15%) required revision in 41 (29.3%) patients. We performed neuraxial neuromodulation trial for 70 patients without going through the team conference from January 2016 to July 2023 with a trial success rate of 45.7% (32 cases). In this group, 7 (21.9%) and 6 (18.8%) patients underwent explant and revision. The differences between the groups were statistically significant for trial success rate (odds ratio of 4.9 with p-value of <0.01) but not for explant (odds ratio of 0.8 with p-value of 0.627) or revision (odds ratio of 0.8 with p-value of 0.595). Conclusion: Implementing Multidisciplinary Team Conference increased trial success rate in our center. Team conference provides therapeutic benefit for patients, and also provides the opportunity for an educational discussion for trainees. [ABSTRACT FROM AUTHOR]

Background: Post-surgical spinal infections (pSSIs) are a serious complication of spinal surgeries, with Staphylococcus spp. being one of the most prominent bacteria identified. Optimal antimicrobial therapy for staphylococcal spinal infections without spinal implants is not well documented. Methods: This single center retrospective 7-year observational study described and compared the outcome (treatment failure or mortality rate one year after diagnosis) of 20 patients with staphylococcal-implant-free pSSI treated with single or combination antibiotics. Results: Median duration of treatment was 40 days (IQR 38–42), with 6 days (IQR 5–7) on intravenous antibiotics and 34 days (IQR 30–36) on oral therapy. Four patients (20%) underwent new surgical debridement, all due to surgical failure, and 1 patient died within the first year without significant differences between both treatment group. Conclusion: This study raises the possibility of single antibiotic therapy for patients with implant-free post-surgical spinal infections due to Staphylococcus spp. [ABSTRACT FROM AUTHOR]

Case: A 30-year-old man had cervical radiculomyelopathy and neck pain caused by a massive intraosseous neurofibroma (IONF) originating from the C6 vertebrae. We performed posterior tumor resection with spinal instrumentation and fusion from C3 to T2 and a follow-up resection procedure of the remaining C6 anterior tumor, sacrificing the affected vertebral artery (VA), which accordingly required bypass surgery at 2 months recovery. Reconstruction using a titanium mesh cage was successfully performed. There were no local recurrences at 2 years postoperatively. Conclusions: Total tumor resection split into 2 stages with sacrifice of the affected VA is a feasible option for treatment of IONF. [ABSTRACT FROM AUTHOR]

The surgical treatment of thoracic spinal tuberculosis has garnered enormous interest from researchers toward the development of posterior surgical techniques that have contributed to greater use of the 1-stage posterior approach. This study aims to demonstrate the initial clinical experience of a modified total posterior approach, in which the 1-stage posterior approach preserves the posterior spinal column structure by combining with the endoprosthetic implant fusion for thoracic spinal tuberculosis. In this clinical study, we intended to report the initial idea of a modified total posterior approach. In detail, a 1-stage posterior approach was applied to preserve the posterior spinal column structure that could be applied to clinical practice. The employed practical procedure presented a reduced duration of surgical intervention and intraoperative trauma. Nevertheless, further studies with large samples and multiple centers are required to explore the idea comprehensively. This approach offered some advantages in terms of intraoperative exposure, blood loss volume, and length of surgery. Further, multicenter studies with large samples are needed to understand the precise effects and implications of the approach. [ABSTRACT FROM AUTHOR]

BACKGROUND: We compared the raw Ti–Al–V super alloy transpedicular implant screws with boronized and surface-hardened transpedicular implant screws. OBJECTIVE: To improve patients' postoperative prognosis with the production of harder and less fragile screws. METHODS: Surface hardening was achieved by applying green-body encapsulation of the specimen with elemental boron paste which is sintered at elevated temperatures to ensure the boron-metal diffusion. Boron transported into the Ti–Al–V super alloy matrix gradually while suppressing aluminum and a homogeneously boronized surface with a thickness of ∼15 microns was obtained. The uniform external shell was enriched with TiB2, which is one of the hardest ceramics. The Ti-Al-V core material, where boron penetration diminishes, shows cohesive transition and ensures intact core-surface structure. RESULTS: Scanning electron microscope images confirmed a complete homogeneous, uniform and non-laminating surface formation. Energy-dispersive X-ray monitored the elemental structural mapping and proved the replacement of the aluminum sites on the surface with boron ending up the TiB2. The procedure was 8.6 fold improved the hardness and the mechanical resistance of the tools. CONCLUSIONS: Surface-hardened, boronized pedicular screws can positively affect the prognosis. In vivo studies are needed to prove the safety of use. [ABSTRACT FROM AUTHOR]

Objective: Dorsal instrumentation using pedicle screws is a standard treatment for multiple spinal pathologies, such as trauma, infection, or degenerative indications. Intraoperative three-dimensional (3D) imaging and navigated pedicle screw placement are used at multiple centers. For the present study, we evaluated a new navigation system enabling augmented reality (AR)-supported pedicle screw placement while integrating navigation cameras into the reference array and drill guide. The present study aimed to evaluate its clinical application regarding safety, efficacy, and accuracy. Methods: A total of 20 patients were operated on between 06/2021 and 01/2022 using the new technique for intraoperative navigation. Intraoperative data with a focus on accuracy and patient safety, including patient outcome, were analyzed. The accuracy of pedicle screw placement was evaluated by intraoperative CT imaging. Results: A median of 8 (4–18) pedicle screws were placed in each case. Percutaneous instrumentation was performed in 14 patients (70%). The duration of pedicle screw placement (duration scan–scan) was 56 ± 26 (30–107) min. Intraoperative screw revision was necessary for 3 of 180 pedicle screws (1.7%). Intraoperatively, no major complications occurred—one case of delay due to software issues and one case of difficult screw placement were reported. Conclusion: The current study's results could confirm the use of the present AR-supported system for navigated pedicle screw placement for dorsal instrumentation in clinical routine. It provides a reliable and safe tool for 3D imaging-based pedicle screw placement, only requires a minimal intraoperative setup, and provides new opportunities by integrating AR. [ABSTRACT FROM AUTHOR]

Diffusion MRI continues to play a key role in non-invasively assessing spinal cord integrity and pre-operative injury evaluation. However, post-operative Diffusion Tensor Imaging (DTI) acquisition of patients with metal implants results in severe geometric distortion. We propose and demonstrate a method to alleviate the technical challenges facing the acquisition of DTI on post-operative cases and longitudinal evaluation of therapeutics. The described technique is based on the combination of the reduced Field-Of-View (rFOV) strategy and the phase segmented EPI, termed rFOV-PS-EPI. A custom-built phantom based on a cervical spine model with metal implants was used to collect DTI data at 3 Tesla scanner using: rFOV-PS-EPI, reduced Field-Of-View single-shot EPI (rFOV-SS-EPI), and conventional full FOV techniques including SS-EPI, PS-EPI, and readout-segmented EPI (RS-EPI). Geometric distortion, SNR, and signal void were assessed to evaluate images and compare the sequences. A two-sample t -test was performed with p -value of 0.05 or less to indicate statistical significance. The reduced FOV techniques showed better capability to reduce distortions compared to the Full FOV techniques. The rFOV-PS-EPI method provided DTI images of the phantom at the level of the hardware whereas the conventional rFOV-SS-EPI is useful only when the metal is approximately 20 mm away. In addition, compared to the rFOV-SS-EPI technique, the suggested approach produced smaller signal voids area as well as significantly reduced geometric distortion in Circularity (p < 0.005) and Eccentricity (p < 0.005) measurements. No statistically significant differences were found for these geometric distortion measurements between the rFOV-PS-EPI DTI sequence and conventional structural T2 images (p > 0.05). The combination of rFOV and a phase-segmented acquisition approach is effective for reducing metal-induced distortions in DTI scan on spinal cord with metal hardware at 3 T. [ABSTRACT FROM AUTHOR]

BACKGROUND: Milling operations of laminae in spinal surgery generate high temperatures, which can lead to thermal injury and osteonecrosis and affect the biomechanical effects of implants, ultimately leading to surgical failure. OBJECTIVE: In this paper, a backpropagation artificial neural network (Bp-ANN) temperature prediction model was developed based on full factorial experimental data of laminae milling to optimize the milling motion parameters and to improve the safety of robot-assisted spine surgery. METHODS: A full factorial experiment design were used to analyze the parameters affecting the milling temperature of laminae. The experimental matrixes were established by collecting the corresponding cutter temperature T c and bone surface temperature T b for the milling depth, feed speed and different bone densities. The Bp-ANN lamina milling temperature prediction model was constructed from experiment data. RESULTS: Increasing milling depth increases bone surface and cutter temperature. Increasing feed speed had little effect on cutter temperature, but decreased bone surface temperature. Increasing bone density of laminae increased cutter temperature. The Bp-ANN temperature prediction model had best training results in the 10th epoch, and there is no overfitting (training set R = 0.99661, validation set R = 0.85003, testing set R = 0.90421, all temperature data set R = 0.93807). The goodness of fit R of Bp-ANN was close to 1, indicating that the predicted temperature was in good agreement with the experiment measurements. CONCLUSION: This study can help spinal surgery-assisted robot to select appropriate motion parameters at different density bones to improve lamina milling safety. [ABSTRACT FROM AUTHOR]

Background: Sufficient surgical resection is necessary for effective tumor control, but is usually limited for vertebral tumors, especially in the cervical spine in small animal neurosurgery. Objective: To evaluate the primary stability and safety of customized three-dimensional (3D)-printed implants for cervical spine reconstruction after total vertebrectomy. Methods: Customized guides and implants were designed based on computed tomography (CT) imaging of five beagle cadavers and were 3D-printed. They were used to reconstruct C5 after total vertebrectomy. Postoperative CT images were obtained to evaluate the safety and accuracy of screw positioning. After harvesting 10 vertebral specimens (C3-C7) from intact (group A) and implanted spines (group B), implant stability was analyzed using a 4-point bending test comparing with groups A and C (reconstituted with plate and pins/ polymethylmethacrylate after testing in Group A). Results: All customized implants were applied without gross neurovascular damage. In addition, 90% of the screws were in a safe area, with 7.5% in grade 1 (< 1.3 mm) and 2.5% in grade 2 (> 1.3 mm). The mean entry point and angular deviations were 0.81 ± 0.43 mm and 6.50 ± 5.11°, respectively. Groups B and C significantly decreased the range of motion (ROM) in C3-- C7 compared with intact spines ( p = 0.033, and 0.018). Both groups reduced overall ROM and neutral zone in C4--C6, but only group B showed significance ( p = 0.005, and 0.027). Conclusion: Customized 3D-printed implants could safely and accurately replace a cervical vertebra in dog cadavers while providing primary stability. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective analysis of prospectively database Objective: Implant-related complications are an extremely important issue because they pose a burden to patients who underwent surgery. An understanding of these complications can help improve the postoperative management of patients undergoing spinal surgery. The current large-scale multicenter study aimed to identify postoperative implant-related complications that may require revision surgery. Methods: In total, 3447 patients who underwent spinal fusion surgery were included in the analysis. Data about age at surgery, sex, preoperative diagnosis, surgical level, type of implant-related complications, causes of reoperation, and time from the initial to revision surgery were reviewed. Moreover, the characteristics of reoperation in 3 periods (within 30, 31–90, and over 90 days) were assessed. Result: The overall incidence of implant-related complications was 4.6%. Adult spinal deformity was the most common diagnosis (9.9%), and thoracic-lumbar-sacral (42.9%) was the most common surgical level among patients with implant-related complications. Further, screw malposition was the most frequent implant-related complication (42.8%). In total, 89 (2.6%) patients underwent reoperation due to implant-related complications. The main causes of reoperation within 30, 31–90, and over 90 days were screw malposition (72.2%), screw loosening or pull out (81.8%), and rod or screw fracture (60.9%), respectively. Conclusion: To the best of our knowledge, this was the first large-scale multicenter study that assessed the characteristics of patients who underwent reoperation due to spinal implant-related complications. The study results could improve the preoperative informed consent procedure about spinal fusion. [ABSTRACT FROM AUTHOR]

Background: The emerging use of three-dimensional printing (3DP) offers improved surgical planning and personalized care. The use of 3DP technology in spinal surgery has several common applications, including models for preoperative planning, biomodels, surgical guides, implants, and teaching tools. Methods: A literature review was conducted to examine the current use of 3DP technology in spinal surgery and identify the challenges and limitations associated with its adoption. Results: The review reveals that while 3DP technology offers the benefits of enhanced stability, improved surgical outcomes, and the feasibility of patient-specific solutions in spinal surgeries, several challenges remain significant impediments to widespread adoption. The obvious expected limitation is the high cost associated with implementing and maintaining a 3DP facility and creating customized patient-specific implants. Technological limitations, including the variability between medical imaging and en vivo surgical anatomy, along with the reproduction of intricate high-fidelity anatomical detail, pose additional challenges. Finally, the lack of comprehensive clinical monitoring, inadequate sample sizes, and high-quality scientific evidence all limit our understanding of the full scope of 3DP's utility in spinal surgery and preclude widespread adoption and implementation. Conclusion: Despite the obvious challenges and limitations, ongoing research and development efforts are expected to address these issues, improving the accessibility and efficacy of 3DP technology in spinal surgeries. With further advancements, 3DP technology has the potential to revolutionize spinal surgery by providing personalized implants and precise surgical planning, ultimately improving patient outcomes and surgical efficiency. [ABSTRACT FROM AUTHOR]

Posterolateral spinal fusion (PLF) is a procedure used for the treatment of degenerative spine disease. In this study we evaluated Osteogrow-C, a novel osteoinductive device comprised of recombinant human Bone morphogenetic protein 6 (rhBMP6) dispersed in autologous blood coagulum with synthetic ceramic particles, in the sheep PLF model. Osteogrow-C implants containing 74–420 or 1000–1700 µm ceramic particles (TCP/HA 80/20) were implanted between L4–L5 transverse processes in sheep (Ovis Aries, Merinolaandschaf breed). In the first experiment (n = 9 sheep; rhBMP6 dose 800 µg) the follow-up period was 27 weeks while in the second experiment (n = 12 sheep; rhBMP6 dose 500 µg) spinal fusion was assessed by in vivo CT after 9 weeks and at the end of the experiment after 14 (n = 6 sheep) and 40 (n = 6 sheep) weeks. Methods of evaluation included microCT, histological analyses and biomechanical testing. Osteogrow-C implants containing both 74–420 and 1000–1700 µm ceramic particles induced radiographic solid fusion 9 weeks following implantation. Ex-vivo microCT and histological analyses revealed complete osseointegration of newly formed bone with adjacent transverse processes. Biomechanical testing confirmed that fusion between transverse processes was complete and successful. Osteogrow-C implants induced spinal fusion in sheep PLF model and therefore represent a novel therapeutic solution for patients with degenerative disc disease. [ABSTRACT FROM AUTHOR]

Considerable research has been focused on identifying the optimum biomaterial for spine implants. New technologies and materials have allowed surgeons to better grasp the biomechanical principles underpinning implant stability and function. An optimal biomaterial for total disc replacement (TDR) should include essential characteristics such as biocompatibility, long-term durability, the capacity to withstand mechanical stresses, and economic viability. Our research has focused on six biomaterials for TDR, including Ti–6Al–4V, CoCr alloy, stainless steel 316L, zirconia toughened alumina (ZTA), polyether ether ketone (PEEK) and ultra-high-molecular weight polyethylene (UHMWPE). Ten common properties, i.e., the Young's modulus, density, tensile strength, the expense of the manufacturing process, the cost of raw material, wear rate, corrosion resistance, thermal conductivity, fracture toughness and compressive strength were utilized to assess these six different materials. The purpose of this study was to evaluate and rank the six alternative biomaterials proposed for use in the endplates and articulating surface of a spinal TDR. To accomplish this, a multi-criteria decision-making approach, namely the fuzzy analytic hierarchy process (fuzzy AHP) and the Technique of Order Preference by Similarity to Ideal Solution (TOPSIS) was adopted to solve the model. For validation and robustness of the proposed method, sensitivity analysis was performed, and comparison was performed with fuzzy-VIKOR and fuzzy-MOORA methods. In light of the study's results, ZTA and Ti–6Al–4V were identified as the best suited materials for the articulating surface and endplates, respectively, in a spinal disc implant. [ABSTRACT FROM AUTHOR]

Spine surgeries are occurring more frequently worldwide. Spinal implant infections are one of the most common complications of spine surgery, with a rate of 0.7% to 11.9%. These implant-related infections are a consequence of surface polymicrobial biofilm formation. New technologies to combat implant-related infections are being developed as their burden increases; however, none have reached the market stage in spine surgery. Conferring antimicrobial properties to biomaterials relies on either surface coating (physical, chemical, or combined) or surface modification (physical, chemical, or combined). Such treatment can also result in toxicity and the progression of antimicrobial resistance. This narrative review will discuss "late-stage" antimicrobial technologies (mostly validated in vivo) that use these techniques and may be incorporated onto spine implants to decrease the burden of implant-related health care-acquired infections (HAIs). Successfully reducing this burden will greatly improve the quality of life in spine surgery. Familiarity with upcoming surface technologies will help spine surgeons understand the anti-infective strategies designed to address the rapidly worsening challenge of implant-related health care-acquired infections. [ABSTRACT FROM AUTHOR]

The technology surrounding spinal fusion surgery has continuously evolved in tandem with advancements made in bioengineering. Over the past several decades, developments in biomechanics, surgical techniques, and materials science have expanded innovation in the spinal implant industry. This narrative review explores the current state of implant surface technologies utilized in spinal fusion surgery. This review covers various types of implant surface materials, focusing on interbody spacers composed of modified titanium, polyetheretherketone, hydroxyapatite, and other materials, as well as pedicle screw surface modifications. Advantages and disadvantages of the different surface materials are discussed, including their biocompatibility, mechanical properties, and radiographic visibility. In addition, this review examines the role of surface modifications in enhancing osseointegration and reducing implant-related complications and, hopefully, improving patient outcomes. The findings suggest that while each material has its potential advantages, further research is needed to determine the optimal surface properties for enhancing spinal fusion outcomes. [ABSTRACT FROM AUTHOR]

Introduction: Hemivertebrae are a common defect of vertebral formation, potentially resulting in debilitating congenital scoliosis and necessitating highly traumatic surgery. Virtual surgical planning (VSP) and 3D-printed patient-specific implants (PSIs) have increasingly been applied to complex spinal surgery, and offer a range of potential benefits. Research Question: We report the use of 3D-printed PSIs and VSP as part of a two-level anterior lumbar interbody fusion (ALIF) for the management of lateral hemivertebra and congenital scoliosis. Material and Methods: A 53-year-old male with chronic low-back pain, due to L4 hemivertebra and mild congenital scoliosis, presented with new-onset leg pain. CT revealed L4/5 and L5/S1 degeneration and foraminal stenosis. Given the complex anatomy and extensive multi-level osteophytosis, 3D-printed PSIs were designed, manufactured, and implanted as part of a two-level ALIF. Results: Excellent implant fit was achieved intraoperatively, confirmed via postoperative imaging. VSP assisted with navigating challenging bony and vascular anatomy. Three-month postoperative imaging demonstrated construct stability, early signs of bony fusion, with implant placement, spinal curvature, and disc height corrections closely matching the VSP. Clinically, the patient’s pain and functional impairment had effectively resolved by nine-month follow up, as demonstrated through subjective and objective measures. Discussion and Conclusions: Virtual surgical planning and 3D-printed PSIs can be useful surgical aids in the management of the often-complex cases involving hemivertebrae and congenital scoliosis. This case of congenital pathology adds to the growing reports of PSI application to a variety of complex spinal pathologies, with analyses showing a close match of the postoperative construct to the preoperative VSP. [ABSTRACT FROM AUTHOR]

Spinal instrumented rod migrating from the surgical site to another remote site in the body is rare. Some cases result in organ or blood vessel injury. Most reported cases were asymptomatic until the finally injuries were generated. We report a unique case of spinal implant failure in which the rod moved from lumbar spine into chest 13 years post lumbar instrumentation. The migrated rod caused no damage to the organs in the pleural cavity but did cause an atypical pleural irritation syndrome which seemed to correlate with the mechanical irritation caused by the rod. These atypical symptoms of rod migration have not been reported previously. [ABSTRACT FROM AUTHOR]

Study Design. A retrospective case series. Objective. This study aims to assess the rates of lumbar interbody cage failures based on their material and manufacturer. Summary of Background Data. Perioperative lumbar interbody cage malfunctions are underreported events in the spine literature and may result in complications. Although the Food and Drug Administration ensures the safety of these devices under physiological conditions after implantation, these devices may experience nonphysiological conditions during implantation, which may be overlooked. Materials and Methods. The MAUDE database was examined for reports of lumbar cage device malfunctions from 2012 to 2021. Each report was categorized based on failure type and implant design. A market analysis was performed by dividing the total number of failures per year for each manufacturer by their approximate yearly revenue from spinal implants in the United States. Outlier analysis was performed to generate a threshold value above which failure rates were defined as greater than the normal index. Results. Overall, 1875 lumbar cage malfunctions were identified. Of these, 1230 (65.6%) were cage breakages, 257 (13.7%) were instrument malfunctions, 177 (9.4%) were cage migrations, 143 (7.6%) were assembly failures, 70 (4.5%) were screw-related failures, and 21 (1.1%) were cage collapses. Of the breakages, 923 (74.9%) occurred during insertion or impaction and 97 entries detailed a medical complication or a retained foreign body. Of the migrations, 155 (88.6%) were identified postoperatively, of which 73 (47.1%) detailed complications and 52 (33.5%) required a revision procedure. Market analysis demonstrated that Medtronic, Zimmer Biomet, Stryker, Seaspine, and K2M exceeded the calculated threshold. Conclusions. Lumbar cages with polyether ether ketone core material failed more frequently by breakage, whereas titanium surface cages failed more frequently by migration. Failure rates varied depending on the manufacturer. Most cage breakages identified in the present study occurred intraoperatively during implantation. These findings call for a more detailed Food and Drug Administration evaluation of these intraoperative malfunctions before commercial approval. [ABSTRACT FROM AUTHOR]

Spinal implants play a vital role in healthcare delivery, and regulations are necessary to ensure their quality, approval, access, and use. In this article, we examine the current state of regulation and approval procedures for medical devices in low- and middle-income countries (LMICs), emphasizing the situation in Tanzania. We conducted a systematic literature search and interviewed a local spine implant representative to investigate the approval, availability, and access of surgical and spinal implants in LMICs, particularly in Africa. Out of the 18 included articles, six referred to African regulations, with no mention of spinal implants. Our analysis revealed that LMICs face challenges in accessing implants due to affordability, poor supply chain, and lack of expertise for their application. However, surgeons have found alternative solutions, such as using lower-cost implants from Turkish manufacturers. The Tanzania Medical Devices and Drugs Authority oversees the local regulatory and approval process for implants. Regulation and accessibility of spinal implants in LMICs, particularly in Africa, are limited and negatively impact patient care and best medical practice. Potential solutions include capacity building within and collaboration among regulatory organizations to improve regulatory processes and allocating financial resources to qualitative and quantitative implant access. [ABSTRACT FROM AUTHOR]

Interbody fusion has recently been successfully used to treat degenerative spinal instability. Without needing to test it in vitro, finite element analysis (FEA) was used to reflect the biomechanical interaction between lumbars and cages. However, the complex geometry of the lumbar region was not accurately modeled by the numerous studies that relied on homogenous, simplified models. This study aims to fill this knowledge gap by creating an inhomogenous lumbar model and using computed tomography finite element analysis (CT-FEA) to assess the biomechanical characteristics of a spinal cage implanted in the model. CT images were used to create a 3D inhomogenous lumbar model of L4-L5. In order to assess the biomechanical characteristics of the implanted cage, a spinal cage was inserted between the lumbar model, and the model was subjected to FEA with loads ranging from 500 N to 1200 N. As the load applied to the assembled model varied from 500 N to 1200 N, the results showed that the maximum principal's stress increased. With values of 12.33 MPa and 0.102 Pa, respectively, the von Mises stress for a load of 500 N had the lowest maximum and minimum values. At 1200 N of force, the highest stress was indicated by the maximum and minimum values of the Von Mises Stress, which were 30.37 MPa and 0.244 Pa, respectively. The stress distribution demonstrated that the inhomogeneous lumbar model was applicable and that using FEA could produce promising results. The significance of taking into account the spinal cages' biomechanical characteristics in non-homogeneous lumbar models is shown by this study. CT-FEA can be a valuable tool for assessing the biomechanical characteristics of spinal cages in non-homogeneous lumbar models. The significance of taking into account the spinal cages' biomechanical characteristics in non-homogeneous lumbar models is shown by this study. [ABSTRACT FROM AUTHOR]

Background: Spinal cord stimulation (SCS) is a surgical technique used in patients with chronic intractable pain, and its effectiveness and safety have been validated by multiple studies. However, to maintain an optimal and steady long-term effect is still challenging. Here, we report a new management paradigm integrating smartphone application and remote programming. Chronic pain patients with SCS implants can monitor their pain status on the phone and change stimulation parameters accordingly. The PreMaSy study is a randomized controlled trial to evaluate the clinical effectiveness and safety of this precise management system. Methods: Patients with chronic intractable pain will be screened for eligibility, and 82 participants are anticipated to be enrolled in this trial. After the electrode implantation, the stimulation effectiveness will be tested. Participants with a reduction of more than 50% in the visual analog scale (VAS) will receive implantation of an implantable pulse generator and randomized (1:1) into the experimental group or control group. All participants will be asked to take online follow-ups and complete assessments using a smartphone application. Daily pain characteristic assessments and monthly quality of life questionnaires are integrated into the App, and participants will be required to complete these assessments. The daily VAS for pain intensity will be monitored and a threshold will be set based on baseline VAS score. The interventional appointment will be scheduled once the threshold is reached. The primary outcome is the health condition and quality of life assessed by the five-level EuroQol five-dimensional questionnaire (EQ-5D-5L). Utility values of EQ-5D-5L will be assessed at baseline and 1, 3, and 6 months post-operative. Discussion: The PreMaSy study aims to evaluate the effectiveness and safety of a novel App-based, patient-centered, self-assessment management system for chronic intractable pain. A randomized controlled trial is designed to test the non-inferiority of this precise management system compared to the monthly online follow-ups. It is also expected to yield valuable experiences regarding precision medicine. Trial registration: ClinicalTrials.gov NCT05761392. Registered on March 07, 2023. [ABSTRACT FROM AUTHOR]

The present study aims to depict the importance of gender-related factors in the subjective perception of spine deformity in adolescents undergoing posterior instrumented fusion for scoliosis. Patients undergoing posterior spinal instrumentation and fusion (PSF) for idiopathic adolescent scoliosis (AIS) were recruited. The following data were recorded: gender, age, parents' civil status, Tegner Activity Scale (TAS), body mass index (BMI), concomitant diseases, and history of neuropsychological disorders. Each patient underwent clinical and radiological evaluations according to the protocol used at our institution. All the patients were assessed before surgery using the following Patient-Reported Outcome Measures (PROMs): the Italian version of the revised Scoliosis Research Society—22 patient questionnaire (SRS-22R), the Quality-of-Life Profile for Spinal Deformities (QLPSDs) questionnaire, and the Spinal Appearance Questionnaire (SAQ). The present study recruited 80 patients (male: 19, female: 61). A significant correlation was observed between BMI, TAS, and subjective perception scores. A worse deformity perception was observed in female patients and patients with divorced parents. Gender-related factors impact the subjective perception of spine deformity in patients undergoing PSF for AIS. Specific assessment and correction are needed to improve postoperative outcomes in these patients. [ABSTRACT FROM AUTHOR]