Factors associated with increased length of stay and risk of complications in 336 patients submitted to spine surgery. The role of a validated capture system (SAVES v2) as a first-line tool to properly face the problem.

PURPOSE: In this study, we analyzed the use of a validated capture system (Spinal Adverse Events Severity system, SAVES V2) as a first non-technical skill to properly face the relevant problem of surgical complications (SCs) and adverse events (AEs) in spinal surgery. METHODS: We retrospectively collected AEs occurring in a tertiary referral center for spine surgery from January 2017 to January 2018 and classified them according to SAVES V2 system. We compared this collection of AEs with a prospective collection performed without any classification system. Univariate and multivariate logistic regression models were used to determined odds ratio (ORs) for selected potential risk factors of AEs and prolonged length of stay. RESULTS: Overall a higher number of AEs was retrospectively recorded using SAVES system compared to the prospective recording without the use of any capture system (97/336 vs 210/336, p < 0.001). The length of stay (LOS) increased in the group of complicated patients for all the procedures examined. In the non-oncological group, LOS was significantly higher for complicated patients compared to uncomplicated patients (F = 44.11, p = 0.0000). Similar results have been obtained in the oncological group of patients. In the multivariate regression model surgical time and postoperative AEs emerged as risk factors for prolonged LOS, while only the presence of previous surgeries was confirmed as risk factor for AEs. CONCLUSION: Considering that the rate of AEs and SCs in spinal surgery is still high despite the improvement of technical skills, we suggest the use of SAVES V2 capture system as a first-line tool to face the problem.

Accurate Signal Conditioning for Pulsed-Current Synchronous Measurements.

This paper describes a compact electronic system employing a synchronous demodulation measurement method for the acquisition of pulsed-current signals. The fabricated prototype shows superior performance in terms of signal-to-noise ratio in comparison to conventional instrumentation performing free-running measurements, especially when extremely narrow pulses are concerned. It shows a reading error around 0.1% independently of the signal duty cycle (D) in the investigated D = 10−4−10−3 range. Conversely, high-precision electrometers display reading errors as high as 30% for a D = 10−4, which reduces to less than 1% only for D > 3 × 10−3. Field tests demonstrate that the developed front-end/readout electronics is particularly effective when coupled to dosimeters irradiated with the X-rays sourced by a medical linear accelerator. Therefore, it may surely be exploited for the real-time monitoring of the dosimeter output current, as required in modern radiotherapy techniques employing ultra-narrow pulses of high-energy photons or nuclear particles.

Deep-Subwavelength 2D Periodic Surface Nanostructures on Diamond by Double-Pulse Femtosecond Laser Irradiation.

Two-dimensional laser-induced periodic surface structures with a deep-subwavelength periodicity (80 nm ≈ λ/10) are obtained for the first time on diamond surfaces. The distinctive surface nanotexturing is achieved by employing a single step technique that relies on irradiation with two temporally delayed and cross-polarized femtosecond-laser pulses (100 fs duration, 800 nm wavelength, 1 kHz repetition rate) generated with a Michelson-like interferometer configuration, followed by chemical etching of surface debris. In this Letter, we demonstrate that, if the delay between two consecutive pulses is ≤2 ps, the 2D periodicity of nanostructures can be tuned by controlling the number of pulses irradiating the surface. Under scanning mode, the method is effective in treating uniformly large areas of diamond, so to induce remarkable antireflection properties able to enhance the absorptance in the visible up to 50 times and to pave the route toward the creation of metasurfaces for future diamond-based optoelectronic devices.

Histological examination of a retrieved custom-made 3D-printed titanium vertebra : Do the fine details obtained by additive manufacturing really promote osteointegration?

PURPOSE: In the present report it is described the design, the manufacturing and the successful surgical implant of one of the first 3D custom titanium vertebra realized with Additive Manufacturing technique and its use for the spinal reconstruction after en-bloc resection for primary osteogenic sarcoma. METHODS: Clinical case presentation and the design of the 3D custom titanium vertebra was reported. It was also described the complex procedures adopted to evaluate the retrieved device from the histological point of view, as a tumor relapse hit the patient, one year after the reconstruction procedure. RESULTS: The histological evaluation confirmed that the resection technique exerts an important role in promoting bone formation: vertebral body osteotomies favored the reconstruction procedure and maximized the contact area between host bone/vertebral prosthesis thus favoring the bone tissue penetration and device colonization. CONCLUSION: The sharing of these results is very important as they represent the starting point for improving the knowledge starting from the evidence obtained in a challenging clinical condition and with post-operative treatments that could be never reproduced in preclinical model.

Spinal surgery complications: an unsolved problem-Is the World Health Organization Safety Surgical Checklist an useful tool to reduce them?

PURPOSE: To investigate whether the World Health Organization Safety Surgical Checklist (SSC) is an effective tool to reduce complications in spinal surgery. METHODS: We retrospectively evaluated the clinical and radiological charts prospectively collected from patients who underwent a spinal surgery procedure from January 2010 to December 2012. The aim of this study was to compare the incidence of complications between two periods, from January to December 2010 (without checklist) and from January 2011 and December 2012 (with checklist), in order to assess the checklist's effectiveness. RESULTS: The sample size was 917 patients with an average of 30-month follow-up. The mean age was 52.88 years. The majority of procedures were performed for oncological diseases (54.4%) and degenerative diseases (39.8%). In total, 159 complications were detected (17.3%). The overall incidence of complications for trauma, infectious pathology, oncology, and degenerative disease was 22.2%, 19.2%, 18.4%, and 15.3%, respectively. No correlation was observed between the type of pathology and the complication incidence. We observed a reduction in the overall incidence of complications following the introduction of the SSC: In 2010 without checklist, the incidence of complications was 24.2%, while in 2011 and 2012, following the checklist introduction, the incidence of complications was 16.7% and 11.7%, respectively (mean 14.2%). CONCLUSIONS: The SSC seems to be an effective tool to reduce complications in spinal surgery. We propose to extend the use of checklist system also to the preoperative and postoperative phases in order to further reduce the incidence of complications. These slides can be retrieved under Electronic Supplementary Material.

Metastatic epidural spinal cord compression: does timing of surgery influence the chance of neurological recovery? An observational case-control study.

PURPOSE: Metastatic epidural spinal cord compression (MESCC) is radiologically defined as an epidural metastatic lesion causing the displacement of the spinal cord from its normal position in the vertebral canal. The purpose of this paper is the evaluation of the influence of timing of surgery on the chance of neurological recovery. METHODS: This is a retrospective observational case-control study performed on patients with MESCC from solid tumors surgically treated at our institute from January 2010 to December 2016. Patients included were divided in two groups depending on surgery that was performed within or after 24 h the admission to the hospital. Neurological status was assessed with American Spine Injury Association (ASIA) Impairment Scale. RESULTS: No statistically significant difference was observed in the variation of ASIA if surgery is performed within or after 24 h from the admission to the hospital. A statistically significant difference was observed after surgery in each group in the improvement of neurological status. A statistically significant difference was reported in the early post-operative complications in patients surgically treated within 24 h. CONCLUSION: MESCC management is challenge for spine surgeons and may represent an oncologic emergency and if not promptly diagnosed can lead to a permanent neurological damage. According to this study, there is no difference in the chance of neurological recovery if surgery is performed within or after 24 h the admission to hospital, but there is a greater rate of early post-operative complications when surgery is performed within 24 h from the admission to the hospital.

Cryosurgery in the excision of a giant local recurrent sacral chordoma: a case report and literature review.

PURPOSE: Chordoma is a low-grade malignant tumor with recurrence and metastasis tendency that originates from embryonic notochordal remnants. The sacrococcygeal region is the most commonly involved site. The aim of this paper is to report the results of the use of cryosurgery in the excision of a giant recurrent sacral chordoma and review of pertinent literature. METHODS: A 64 years old female patient with a locally recurrent sacral chordoma came to our attention after ten interventions performed at another institute. A surgical treatment was performed using argon cryosurgery. RESULTS: In this case, it was not possible to perform a marginal or wide excision, but it was intralesional with the removal of three major blocks. The fragments sent for the histological analysis measured total 35 × 30 × 8 cm with a weight of 4.260 g. CONCLUSIONS: Given the gelatinous structure of the tumor and the possibility of contamination of operatory field, cryosurgery may be indicated when previous surgeries and the dimensions of tumor mass do not allow a resection with negative margins improving radiotherapy efficacy in the local control of tumor.

Biomimetic 3D-printed custom-made prosthesis for anterior column reconstruction in the thoracolumbar spine: a tailored option following en bloc resection for spinal tumors : Preliminary results on a case-series of 13 patients.

PURPOSE: Various techniques for anterior column reconstruction have been described after en bloc resection of spinal tumors. Limited evidence exists regarding one being superior to another. The purpose of this study is to evaluate 3D-printed vertebral bodies for spinal reconstruction after en bloc resection in the thoracolumbar spine. METHODS: Prospective observational study on custom-made 3D-printed titanium reconstruction of vertebral bodies after en bloc resection for spinal tumor was conducted between November 2015 and June 2017. 3D-printed vertebral bodies were monitored for mechanical complications such as (1) migration, (2) subsidence into the adjacent vertebral bodies, and/or (3) breakage. Complications and related details were recorded. RESULTS: Thirteen patients (7 females and 6 males) were enrolled, and reconstruction of the anterior column was performed using custom-made 3D-printed titanium prosthesis after en bloc resection for spinal tumor (8 primary bone tumors and 5 solitary metastases). Subsidence into the adjacent vertebral bodies occurred in all patients at both proximal and distal bone-implant interfaces; however, it was clinically irrelevant (asymptomatic, and no consequences on posterior instrumentation), in 11 out of 12 patients (92%). In 1 patient (#4), severity of the subsidence led to revision of the construct. At an average 10-month follow-up (range 2-16), 1 implant was removed due to local recurrence of the disease and 1 was revisioned due to progressive distal junctional kyphosis. CONCLUSION: Preliminary results from this series suggest that 3D printing can be effectively used to produce custom-made prosthesis for anterior column reconstruction. These slides can be retrieved under Electronic Supplementary Material.

Solitary bone cyst of a lumbar vertebra treated with percutaneous steroid injection: a case report and review of literature.

PURPOSE: We describe a rare case of solitary bone cyst involving the vertebral body of L4. INTRODUCTION: To the best of the authors' knowledge, only 15 cases of solitary bone cysts involving the spine have been reported previously. All the reported cases were treated surgically, including resection and curettage with or without bone grafting. In the current case, treatment was with steroid injection alone. METHOD: A cystic lesion involving the vertebral body of L4 was identified in a 16-year-old girl with persistent low back pain of 2 years' duration. According to the radiological characteristics of the lesion, a diagnosis of solitary bone cyst was suspected. The patient underwent surgical intervention with percutaneous steroid injection alone since there was no evidence of thinned cortex or pathological fracture. The patient was discharged 2 days after this intervention with resolution of the low back pain. RESULT: At the final follow-up 7 months after treatment, the patient was asymptomatic and the beginning of bony healing was evident. CONCLUSION: Herein, we reported an extremely rare case of solitary bone cyst involving the body of the fourth lumbar vertebra. Local steroid injection should be considered as a minimally invasive intervention for a solitary bone cyst involving the spinal column with no evidence of thinned cortex or pathological fracture.

Aneurysmal bone cyst of the spine treated by concentrated bone marrow: clinical cases and review of the literature.

PURPOSE: ABC is a benign lesion with unpredictable behavior. Its treatment is challenging, especially in poorly accessible surgical areas, such as spine and pelvis. Currently, the first-line treatment of ABC is repeated selective arterial embolization (SAE) until healing. Other options have been used with variable success rates. We propose an alternative treatment for spine aneurysmal bone cyst (sABC) based on the injection of concentrated autologous bone marrow. METHODS: We retrospectively report and analyze here two cases of patients, a 14-year-old girl and a 16-year-old boy, both affected by ABC in C2 vertebra which were impossible to treat by SAE. They were treated with single or repeated injection of concentrated autologous bone marrow into the lesion. Their follow-up period is 27 months for both patients. RESULTS: In the two cases reported here we observed a progressive ossification of the lesion, which was slow in one case, requiring three subsequent injections of concentrated bone marrow, and fast in the other case, beginning 1 month after the procedure. In both cases, the healing of the lesion was associated with symptom relief and the clinical status of the patients remains stable after 2 years. CONCLUSIONS: Although SAE can still be considered the first line in the treatment of ABC in the axial skeleton, new promising therapeutic procedures involving the use of mesenchymal stem cells are developing.

A readout system for highly sensitive diamond detectors for FLASH dosimetry.

Accurate dosimetry of ultra-high dose-rate beams using diamond detectors remains challenging, primarily due to the elevated photocurrent peaks exceeding the input dynamics of precision electrometers. This work aimed at demonstrating the effectiveness of compact gated-integration electronics in conditioning the current peaks (>20 mA) generated by a highly sensitive (S ≃ 26 nC/Gy) custom-made diamond photoconductor under electron FLASH irradiation, as well as in real-time monitoring of beam dose and dose-rate. For the emerging FLASH technology, this study provided a new perspective on using commercially available diamond dosimeters with high sensitivity, currently employed in conventional radiotherapy.

Structural and Photoelectronic Properties of κ-Ga2O3 Thin Films Grown on Polycrystalline Diamond Substrates.

Orthorhombic κ-Ga2O3 thin films were grown for the first time on polycrystalline diamond free-standing substrates by metal-organic vapor phase epitaxy at a temperature of 650 °C. Structural, morphological, electrical, and photoelectronic properties of the obtained heterostructures were evaluated by optical microscopy, X-ray diffraction, current-voltage measurements, and spectral photoconductivity, respectively. Results show that a very slow cooling, performed at low pressure (100 mbar) under a controlled He flow soon after the growth process, is mandatory to improve the quality of the κ-Ga2O3 epitaxial thin film, ensuring a good adhesion to the diamond substrate, an optimal morphology, and a lower density of electrically active defects. This paves the way for the future development of novel hybrid architectures for UV and ionizing radiation detection, exploiting the unique features of gallium oxide and diamond as wide-bandgap semiconductors.

Imaging of Spondylodiscitis: A Comprehensive Updated Review-Multimodality Imaging Findings, Differential Diagnosis, and Specific Microorganisms Detection.

Spondylodiscitis is defined by infectious conditions involving the vertebral column. The incidence of the disease has constantly increased over the last decades. Imaging plays a key role in each phase of the disease. Indeed, radiological tools are fundamental in (i) the initial diagnostic recognition of spondylodiscitis, (ii) the differentiation against inflammatory, degenerative, or calcific etiologies, (iii) the disease staging, as well as (iv) to provide clues to orient towards the microorganisms involved. This latter aim can be achieved with a mini-invasive procedure (e.g., CT-guided biopsy) or can be non-invasively supposed by the analysis of the CT, positron emission tomography (PET) CT, or MRI features displayed. Hence, this comprehensive review aims to summarize all the multimodality imaging features of spondylodiscitis. This, with the goal of serving as a reference for Physicians (infectious disease specialists, spine surgeons, radiologists) involved in the care of these patients. Nonetheless, this review article may offer starting points for future research articles.

Metal-Halide Perovskite Submicrometer-Thick Films for Ultra-Stable Self-Powered Direct X-Ray Detectors.

Metal-halide perovskites are revolutionizing the world of X-ray detectors, due to the development of sensitive, fast, and cost-effective devices. Self-powered operation, ensuring portability and low power consumption, has also been recently demonstrated in both bulk materials and thin films. However, the signal stability and repeatability under continuous X-ray exposure has only been tested up to a few hours, often reporting degradation of the detection performance. Here it is shown that self-powered direct X-ray detectors, fabricated starting from a FAPbBr3 submicrometer-thick film deposition onto a mesoporous TiO2 scaffold, can withstand a 26-day uninterrupted X-ray exposure with negligible signal loss, demonstrating ultra-high operational stability and excellent repeatability. No structural modification is observed after irradiation with a total ionizing dose of almost 200 Gy, revealing an unexpectedly high radiation hardness for a metal-halide perovskite thin film. In addition, trap-assisted photoconductive gain enabled the device to achieve a record bulk sensitivity of 7.28 C Gy-1 cm-3 at 0 V, an unprecedented value in the field of thin-film-based photoconductors and photodiodes for "hard" X-rays. Finally, prototypal validation under the X-ray beam produced by a medical linear accelerator for cancer treatment is also introduced.

Image-Guided Minimally Invasive Treatment Options for Degenerative Lumbar Spine Disease: A Practical Overview of Current Possibilities.

Lumbar back pain is one of the main causes of disability around the world. Most patients will complain of back pain at least once in their lifetime. The degenerative spine is considered the main cause and is extremely common in the elderly population. Consequently, treatment-related costs are a major burden to the healthcare system in developed and undeveloped countries. After the failure of conservative treatments or to avoid daily chronic drug intake, invasive treatments should be suggested. In a world where many patients reject surgery and prefer minimally invasive procedures, interventional radiology is pivotal in pain management and could represent a bridge between medical therapy and surgical treatment. We herein report the different image-guided procedures that can be used to manage degenerative spine-related low back pain. Particularly, we will focus on indications, different techniques, and treatment outcomes reported in the literature. This literature review focuses on the different minimally invasive percutaneous treatments currently available, underlining the central role of radiologists having the capability to use high-end imaging technology for diagnosis and subsequent treatment, allowing a global approach, reducing unnecessary surgeries and prolonged pain-reliever drug intake with their consequent related complications, improving patients' quality of life, and reducing the economic burden.

Correlation Between Sagittal Balance and Mechanical Distal Junctional Failure in Degenerative Pathology of the Spine: A Retrospective Analysis.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: This study aimed to investigate the failure of the caudal end of lumbar posterior fixation in terms of pre-operative and post-operative spinopelvic parameters, correction performed, demographic and clinical data. METHODS: The lumbar, thoraco-lumbar and lumbo-sacral posterior fixations performed with pedicle screws and rods in 2017-2019 were retrospectively analyzed. As 81% failures occurred within 4 years, an observational period of 4 years was chosen. The revision surgeries due to the failure in the caudal end were collected in the junctional group. Fixations which have not failed were gathered in the control group. The main spinopelvic parameters were measured for each patient on standing lateral radiographs with the software Surgimap. Demographic and clinical data were extracted for both groups. RESULTS: Among the 457 patients who met the inclusion criteria, the junctional group included 101 patients, who required a revision surgery. The control group collected 356 primary fixations. The two most common causes of revision surgeries were screws pullout (57 cases) and rod breakage (53 cases). SVA, PT, LL, PI-LL and TPA differed significantly between the two groups (P = .021 for LL, P < .0001 for all the others). The interaction between the two groups and the pre-operative and post-operative conditions was significant for PT, SS, LL, TK, PI-LL and TPA (P < .005). Sex and BMI did not affect the failure onset. CONCLUSIONS: Mechanical failure is more likely to occur in patients older than 40 years with a thoraco-lumbar fixation where PT, PI-LL and TPA were not properly restored.

A Highly Versatile X-ray and Electron Beam Diamond Dosimeter for Radiation Therapy and Protection.

Radiotherapy is now recognized as a pillar in the fight against cancer. Two different types are currently used in clinical practice: (1) external beam radiotherapy, using high-energy X-rays or electron beams, both in the MeV-range, and (2) intraoperative radiotherapy, using low-energy X-rays (up to 50 keV) and MeV-range electron beams. Versatile detectors able to measure the radiation dose independently from the radiation nature and energy are therefore extremely appealing to medical physicists. In this work, a dosimeter based on a high-quality single-crystal synthetic diamond sample was designed, fabricated and characterized under low-energy X-rays, as well as under high-energy pulsed X-rays and electron beams, demonstrating excellent linearity with radiation dose and dose-rate. Detector sensitivity was measured to be 0.299 ± 0.002 µC/Gy under 6 MeV X-ray photons, and 0.298 ± 0.004 µC/Gy under 6 MeV electrons, highlighting that the response of the diamond dosimeter is independent of the radiation nature. Moreover, in the case of low-energy X-rays, an extremely low limit of detection (23 nGy/s) was evaluated, pointing out the suitability of the device to radiation protection dosimetry.

Frenkel-Poole Mechanism Unveils Black Diamond as Quasi-Epsilon-Near-Zero Surface.

A recent innovation in diamond technology has been the development of the "black diamond" (BD), a material with very high optical absorption generated by processing the diamond surface with a femtosecond laser. In this work, we investigate the optical behavior of the BD samples to prove a near to zero dielectric permittivity in the high electric field condition, where the Frenkel-Poole (FP) effect takes place. Zero-epsilon materials (ENZ), which represent a singularity in optical materials, are expected to lead to remarkable developments in the fields of integrated photonic devices and optical interconnections. Such a result opens the route to the development of BD-based, novel, functional photonic devices.

Carbon Fiber-Reinforced PolyEtherEtherKetone (CFR-PEEK) Instrumentation in Degenerative Disease of Lumbar Spine: A Pilot Study.

CFR-PEEK is gaining popularity in spinal oncological applications due to its reduction of imaging artifacts and radiation scattering compared with titanium, which allows for better oncological follow-up and efficacy of radiotherapy. We evaluated the use of these materials for the treatment of lumbar degenerative diseases (DDs) and considered the biomechanical potential of the carbon fiber in relation to its modulus of elasticity being similar to that of bone. Twenty-eight patients with DDs were treated using CRF-PEEK instrumentation. The clinical and radiographic outcomes were collected at a 12-month FU. Spinal fusion was evaluated in the CT scans using Brantigan scores, while the clinical outcomes were evaluated using VAS, SF-12, and EQ-5D scores. Out of the patients evaluated at the 12-month FU, 89% showed complete or almost certain fusion (Brantigan score D and E) and presented a significant improvement in all clinical parameters; the patients also presented VAS scores ranging from 6.81 ± 2.01 to 0.85 ± 1.32, EQ-5D scores ranging from 53.4 ± 19.3 to 85.0 ± 13.7, SF-12 physical component scores (PCSs) ranging from 29.35 ± 7.04 to 51.36 ± 9.75, and SF-12 mental component scores (MCSs) ranging from 39.89 ± 11.70 to 53.24 ± 9.24. No mechanical complications related to the implant were detected, and the patients reported a better tolerance of the instrumentation compared with titanium. No other series of patients affected by DD that was stabilized using carbon fiber implants have been reported in the literature. The results of this pilot study indicate the efficacy and safety of these implants and support their use also for spinal degenerative diseases.

Indications and Limits of Surgery for Spinal Metastases Derived from Lung Cancer: A Single-Center Experience.

Lung cancer is the second most frequently diagnosed cancer in the world, and surgery is an integral part of the treatment for spinal metastases. The aims of this retrospective study were to assess the overall survival of surgically treated patients affected by lung cancer spinal metastases and identify any factors related to a better survival rate. We recruited 56 consecutive patients (34 male and 22 female) surgically treated for metastatic lung cancer in the spine from 2009 to 2019. Surgical indications were based on a previously published and validated flow chart following a multidisciplinary evaluation. We assessed the localization of vertebral metastases, the presence of other bone or visceral metastases, neurological status according to the Frankel score, ambulatory autonomy, and general status, measured with the Karnofsky performance scale. The expected prognosis was retrospectively assessed according to the revised Tokuhashi score. The median survival was 8.1 months, with over a third of patients surviving more than 1 year. We observed a global improvement in all clinical parameters after surgical treatment. The Tokuhashi predictive score did not correlate with survival after surgery. The results of this study suggest that the surgical treatment of symptomatic spinal metastases from lung cancer can improve quality of life, even in patients with a shorter life expectancy, by controlling pain and improving autonomy.