Substrate evaporation drives collective construction in termites.

Termites build complex nests which are an impressive example of self-organization. We know that the coordinated actions involved in the construction of these nests by multiple individuals are primarily mediated by signals and cues embedded in the structure of the nest itself. However, to date there is still no scientific consensus about the nature of the stimuli that guide termite construction, and how they are sensed by termites. In order to address these questions, we studied the early building behavior of Coptotermes gestroi termites in artificial arenas, decorated with topographic cues to stimulate construction. Pellet collections were evenly distributed across the experimental setup, compatible with a collection mechanism that is not affected by local topography, but only by the distribution of termite occupancy (termites pick pellets at the positions where they are). Conversely, pellet depositions were concentrated at locations of high surface curvature and at the boundaries between different types of substrate. The single feature shared by all pellet deposition regions was that they correspond to local maxima in the evaporation flux. We can show analytically and we confirm experimentally that evaporation flux is directly proportional to the local curvature of nest surfaces. Taken together, our results indicate that surface curvature is sufficient to organize termite building activity and that termites likely sense curvature indirectly through substrate evaporation. Our findings reconcile the apparently discordant results of previous studies.

The Incidence of Screw Failure in Fenestrated Polyaxial Pedicle Screws vs. Conventional Pedicle Screws in the Treatment of Adolescent Idiopathic Scoliosis (AIS).

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.

Short-segment percutaneous fusion versus open posterior fusion with screw in the fractured vertebra for thoracolumbar junction burst vertebral fracture treatment.

Objectives: The treatment options for thoracolumbar junction burst fractures remain a topic of controversy. Short-segment percutaneous fixation (SSPF) and short-segment open fixation including the fractured level (SSOFIFL) are both viable procedures for managing these fractures. At present, there is a lack of evidence in the literature demonstrating the absolute superiority of one treatment over the other. This study aimed to compare these two surgical strategies with a focus on radiological and clinical outcomes. Materials and Methods: This retrospective case-control multicenter analysis involved patients with A3 and A4 vertebral fractures at the thoracolumbar junction (T11-L2) who underwent surgical treatment with either SSPF or SSOFIFL in the participating centers. Clinical outcomes were measured using the Oswestry Disability Index and visual analogue scale (VAS) both pre- and postoperatively. Radiological outcomes included kyphotic deformity (KD), anterior vertebral body height (AVBH), segmental kyphosis, and sagittal alignment parameters. Results: A total of 156 patients were enrolled in the study, with 81 patients in Group A (SSPF) and 75 patients in Group B (SSOFIFL). Group B demonstrated better correction of KD (Group B: 3.4 ± 2.7° vs. Group A: 8.3 ± 3.2°, P = 0.003), AVBH, and sagittal alignment. A minor loss of correction was observed in Group B with respect to Group A (0.9 ± 1.7° vs 4.3° ± 2.1°, P = 0.043). Blood losses were lower in Group A (78 ± 15 min vs. 118 ± 23 min, P = 0.021) as well as during surgery (121.3 ± 34 mL vs. 210.2 ± 52 mL, P = 0.031), but the post-operative hemoglobin levels were comparable between the two groups. Conclusion: SSOFIFL appears to show a major amount of KD correction and prevent loss of correction. This technique should be the preferred choice whenever possible. However, SSPF can be considered a valid alternative for damage control in polytrauma patients and fractures with low KD.

Vertebral Candidiasis, the State of the Art: A Systematic Literature Review.

OBJECTIVE: In recent years, Candida spondylodiscitis has represented an increasingly emerging disease in clinical practice. This condition requires long-term antibiotic therapy and sometimes surgical treatments. The main purpose of this study is to investigate the epidemiology, clinical and radiological aspects, treatment protocols, and outcomes of Candida-mediated vertebral osteomyelitis. METHODS: A systematic review of the English literature was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.The research was conducted on Medline, Cochrane library, PubMed, and Scopus using as search terms "vertebral"; "spinal"; "infection"; "spondylodiscitis"; "discitis"; "osteomyelitis"; "Candida"; and "Candidosis." A case of vertebral candidiasis that was surgically managed was also reported. RESULTS: In total, 88 articles were included in our systematic review. Including the reported case, our analysis covered 113 cases of vertebral candidiasis. Candida albicans was isolated in 64 cases (56.1%), Candida tropicalis in 21 (18.4%), Candida glabrata in 14 (12.3%), and Candida parapsilosis in five (4.4%). The mean duration of the follow-up was 395 days. Finally, 87 (82%) patients completely recovered, ten (9.4%) died, and nine (8.5%) reported sequelae. CONCLUSION: This systematic review summarized the state of the art on vertebral candidiasis, describing data on its clinical features, diagnostic criteria and current limitations, and treatment alternatives and their outcomes.

Long-Term Clinical and Radiographic Outcomes After Bryan Cervical Disk Arthroplasty: A Systematic Literature Review.

Introductionː Cervical disk arthroplasty is a potential alternative procedure to anterior cervical decompression and fusion for the treatment of cervical disk disease. The aim of the study was to perform a systematic literature review on long-term clinical and radiological outcomes after Bryan cervical disk arthroplasty.Material and Methodsː A systematic literature review was performed according to PRISMA guidelines via PubMed and Embase, Scopus, and the Cochrane Library database by using the following keywords: "Bryan prosthesis"; "cervical disk arthroplasty"; "outcomes"; and "long-term follow-up." Eight articles with at least 10 years of follow-up were considered for eligibility.Resultsː In total, 481 patients were enrolled in the studies. Because of the occurrence of multiple treated levels, 588 arthroplasties were performed, divided as follows: 12 C3/4 cervical disk arthroplasties (2.01%), 63 C4/5 (10.71%), 325 C5/6 (55.27%), and 188 C6/7 (31.97%). The mean preoperative cervical lordosis was 13.6 ± 9.3°, whereas the last follow-up value was 12.8 ± 8.7°. In the last follow-up, the mean segmental range of motion was 8.2 ± 3.3°.Discussion: Recent studies have suggested that cervical disk arthroplasty should be safely performed in healthy young patients with disk degeneration who may need future revision surgery. The results suggest that this procedure preserves native cervical spinal biomechanics at long-term follow-up with acceptable adjacent segments disease and periprosthetic ossifications.Conclusionsː Cervical disk arthroplasty has good long-term device survival, motility, adjacent segment degeneration, and clinical outcomes. Therefore, it represents a valid alternative for the treatment of cervical spine degenerative pathologies, especially in young patients.

Extreme Lateral Interbody Fusion (XLIF) with Lateral Modular Plate Fixation: Preliminary Report on Clinical and Radiological Outcomes.

The lateral transpsoas approach (extreme lateral interbody fusion, or XLIF) allows surgeons to use various lordotic cage sizes to help restore intervertebral disk height, correct sagittal alignment, and improve fusion rates. The use of standalone devices has consistently raised doubts due to the high risk of complications and inadequate functional recovery that a circumferential arthrodesis can support. The recent introduction of a novel XLIF cage with adapted lateral plate fixation (XLPF) may further enhance the structural rigidity, consolidating the cage and plate into a singular modular entity. Nine patients from our surgical centers underwent a procedure of 1-level XLIF with XLPF in selected cases. We observed that XLPF does not extend the intraoperative footprint and provides immediate rigidity to the anterior column without any additional risk of complications and with minimal increased time compared to the traditional cage implant procedure. Although it has been shown that the use of interbody fusion cages with supplemental posterior fixation improves stabilization in all directions, the technique of standalone lateral cages may also have a place in spine surgery in that the stability may be sufficient in selected cases, such as junctional syndrome and in some forms of degenerative scoliosis.

Electrochemotherapy in the Treatment of Bone Metastases: A Systematic Review.

BACKGROUND AND AIM: Cancers are one of the most frequent causes of death and disability in humans. Skeletal involvement has a major impact on the quality of life and prognosis of cancer patients. Electrochemotherapy is a palliative and minimally invasive oncologic treatment that was first used to treat subcutaneous nodules for malignant tumors. The aim of our review is to evaluate the results of electrochemotherapy in the treatment of bone metastases. METHODS: A systematic review of the literature indexed in the PubMed MEDLINE and Cochrane Library databases using the search key words "electrochemotherapy" AND ("metastasis" OR "metastases") was performed. The Preferred Reporting Items for Systematic Reviews and MetaAnalyses was followed. Inclusion criteria were proven involvement of the appendicular skeleton in metastatic carcinoma or melanoma, through at least one percutaneous electrochemotherapy session on the metastatic bone lesion. The exclusion criterion was no skeletal metastatic involvement. RESULTS: Eight articles were finally included. We reached a population of 246 patients. The mean age and follow up were 60.1 years old and 11.4 months, respectively. The most represented primary tumor was breast cancer (18.9%). A total of 250 bone lesions were treated with electrochemotherapy. According to RECIST criteria, in our population we observed 55.5% stable diseases. The mean pre-electrochemotherapy VAS value was 6.9, which lowered to 2.7 after treatment. Adverse events occurred in 3.4% of patients. CONCLUSIONS: Electrochemotherapy as a minimally invasive and tissue-sparing treatment should be considered for patients with no other alternative to obtain tumor control and improvement in quality of life.

Positioning accuracy and facet joints violation after percutaneous pedicle screws placement with robot-assisted versus fluoroscopy-guided technique: Systematic review and meta-analysis.

Introduction: Minimally invasive spine surgery became the gold standard for the treatment of many spinal diseases. Only a few comparative studies were performed regarding the superiority of robotic-assisted (RA) surgery over fluoroscopic guidance (FG) surgery during percutaneous pedicle screws placement. Therefore, the aim of the present study was to conduct a systematic literature review and meta-analysis to evaluate the accuracy and potential advantages of RA compared with FG. Material and Methods: This study is a systematic literature review conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. The review questions were formulated following the PICO scheme. Measured outcomes were presented using Forest plots. Heterogeneity among the included studies was assessed using the χ2 test, and the I2 statistic was utilized to estimate the proportion of total variation among the studies. A value exceeding 50% was considered indicative of substantial heterogeneity. Results: Seven studies that met inclusion criteria were finally included in this meta-analysis. These seven studies include: 447 patients, 228 patients (931 screws) treated with robotic guide, and 219 patients (767 pedicle screws) using fluoroscopic guide, with a mean age of 55.2. The percentages of clinically acceptable screws were 94.3% in the robot-assisted group and 89% in the fluoroscopic guided group. The percentages of non-acceptable screws were 5.7% in the robot-assisted group and 11% in the fluoroscopic-guided group. Discussion: Significant differences were observed between the two groups in terms of radiographic and clinical outcomes, with the robotic-assisted pedicle screw group exhibiting longer operative times. Robot technology serves as a valuable tool for assisting surgeons in challenging scenarios such as anatomical variants or patients with spinal deformities, ensuring accurate screw placement. Conclusion: The accuracy of pedicle screw placement with robotic technology is higher than with FG. In fact, the robotic approach allows significantly lower complication rates, fewer cases of violation of the proximal articular facet, less intraoperative exposure to radiation, even if it requires longer surgical times than the FG technique.

Thoracic synovial cyst as cause of cord compression in a patient with Charcot-Marie-Tooth disease.

An 80-year-old male patient affected by Charcot-Marie-Tooth (CMT) disease came to our attention in July 2020, for the occurrence of low back pain and lower limb weakness, and also saddle anesthesia, urinary and faecal retention were referred. His diagnosis of CMT is dated back to 1955 and through the years, the clinical picture slowly worsened but never got particularly severe. The quick symptoms outbreak and the presence of urinary disturbances were red flags, which lead us to direct the diagnostic orientation elsewhere. A Magnetic Resonance Imaging of the thoraco-lumbar spinal cord was then performed and it was suggestive for synovial cyst at T10-T11. The patient underwent a decompression with laminectomy and then stabilized through arthrodesis. In the very next days after the surgery, the patient showed a sudden and significant improvement of his condition. At the last visit, he showed a remarkable relief of the symptoms, walking by himself.

Clinical usefulness of nutraceutics with acetyl-L-carnitine, α-lipoic acid, phosphatidylserine, curcumin, C, E and B-group vitamins in patients awaiting for carpal tunnel release during COVID-19 pandemic: a randomized controlled open label prospective study.

BACKGROUND AND AIM OF THE WORK: Carpal Tunnel Syndrome (CTS) is provoked by the compression of the median nerve, leading to nerve ischemia, endoneural edema, venous congestion, and subsequent metabolic alterations. Conservative treatments could be considered. The present study investigates the efficacy of a specific blend of a 600 mg dietary integrator composed of acetyl-L-carnitine, α-lipoic acid, phosphatidylserine, Curcumin, C, E and B1, B2, B6 and B12 vitamins in patients with mild to moderate CTS. METHODS: The present investigation involved the outpatients who were planned to undergo open surgical decompression of the median nerve awaiting surgery from June 2020 and February 2021. CTS surgery has been significantly reduced in our institutions during the COVID-19 pandemic. Patients were randomized into Group A (dietary integration 600 mg twice day for 60 days) and Group B (control group, no drug administration). Clinical and functional improvement was prospectively measured after 60 days Results: One-hundred forty-seven patients completed the study, 69 from group A and 78 from group B. BCTQ was significantly improved with the drug administration, as well as BCTQ symptoms subscale, and the pain. BCTQ function subscale and Michigan Hand Questionnaire was not significantly improved. Ten patients in group A (14.5%) declared that they didn't need further treatment. No major side effects were noticed. CONCLUSIONS: Dietary integration could be considered as an option in patients who could not undergo surgery. Symptoms and pain could improve, but surgery remains the gold standard for recovery of function in mild to moderate CTS.

Editorial on: Musculoskeletal Rehabilitation: Current Challenges and New Perspectives.

Musculoskeletal disorders are among the leading causes of disability and chronic pain worldwide, and their impact is expected to increase in the coming years [...].

Correlation between traumatic pelvic ring injuries and sexual dysfunctions: a multicentric retrospective study.

PURPOSE: Among the functional impairments associated with pelvic ring injuries (PRI), sexual dysfunction (SD) is a common clinical issue. The aim of this study is to investigate correlations between traumatic PRI, genitourinary, and sexual dysfunctions, for a proper multidisciplinary treatment. METHODS: We performed an observational, multicentric study, from January 2020 to 2022. We conducted a follow-up after surgery at three, six, 12, and 24 months by measuring the Female Sexual Functioning Index (FSFI), the International Index of Erectile Function (IIEF), the Arizona Sexual Experience Scale (ASEX), the Majeed Score, and the SF-12. Descriptive statistics was conducted on T-test, Whelc's test, and one-way ANOVA which were performed when appropriate. RESULTS: A total of 76 patients (mean age 42.17 ± 15 years) were included in the study and allocated into three groups (A, B, and C). Tile A group revealed good sexual outcomes, similar to that of healthy patients. Tile B group demonstrated worsen SD than the previous group. In Tile C group, there was a longer average duration of the orthopaedic surgery when compared to group B. However, in terms of SDs, statistical significance could not be demonstrated between groups C and B. CONCLUSIONS: We observed a progressive spontaneous recovery of sexual function, corresponding to each PRI group. Moreover, men classified as B2 had milder SDs than B1 male patients.

Increased Frequency of Hand Hygiene and Other Infection Prevention Practices Correlates with Reduced Surgical Wound Infection Rates in Spinal Surgery during the COVID-19 Pandemic.

BACKGROUND: Due to the COVID-19 pandemic outbreak, many changes were done in the hospital practice, and new guidelines were issued in order to contain the infection spread. One of the most common measures is represented by a correct and frequent hand washing. Recently, an association between increased adherence to hand hygiene (HH) protocols and reduction in hospital infections was documented however no studies about the surgical wound infection rate were reported in the Literature. METHODS: The present study represents a multicentric retrospective epidemiological study. The HH compliance rate was recorded through direct observations by trained nurses, 24 h a day. The primary outcome was HH compliance rate. The association of HH with spinal surgical wound infections was the secondary outcome. RESULTS: We reported a compliance to HH practices during the pandemic period of 85.2% compared with 57% observed during 2019. Our analysis showed an overall surgical wound infection reduction of 66.6% during the hospital stay in the pandemic period. CONCLUSION: Hand hygiene has always been considered one of the most effective, reproducible and low-cost weapons to deal with hospital infections. The good health habits acquired during the COVID-19 pandemic should be maintained even after the virus is eradicated.

The Feasibility of a Primary Care Based Navigation Service to Support Access to Health and Social Resources: The Access to Resources in the Community (ARC) Model.

Introduction: We established a patient centric navigation model embedded in primary care (PC) to support access to the broad range of health and social resources; the Access to Resources in the Community (ARC) model. Methods: We evaluated the feasibility of ARC using the rapid cycle evaluations of the intervention processes, patient and PC provider surveys, and navigator log data. PC providers enrolled were asked to refer patients in whom they identified a health and/or social need to the ARC navigator. Results: Participants: 26 family physicians in four practices, and 82 of the 131 patients they referred. ARC was easily integrated in PC practices and was especially valued in the non-interprofessional practices. Patient overall satisfaction was very high (89%). Sixty patients completed the post-intervention surveys, and 33 reported accessing one or more service(s). Conclusion: The ARC Model is an innovative approach to reach and support a broad range of patients access needed resources. The Model is feasible and acceptable to PC providers and patients, and has demonstrated potential for improving patients' access to health and social resources. This study has informed a pragmatic randomized controlled trial to evaluate the ARC navigation to an existing web and telephone navigation service (Ontario 211).

Does the Use of Gelled Platelet-Rich Plasma during Fixation of Subacute Proximal Pole Scaphoid Fractures Help? - A Single Centre Experience.

Background: Subacute proximal pole scaphoid fractures (1 month to 6 months) have a higher risk of non-union. The aim of the present retrospective analysis is to evaluate the efficacy of gelled platelet-rich plasma (GPRP) as additional treatment to antegrade headless screw fixation of proximal pole scaphoid fractures. Methods: Forty-one patients were divided into two groups based on surgical treatment received: screw fixation alone (group A) and screw fixation and GPRP application at the fracture site (group B). A short cast was maintained for 4 weeks after surgery. Outcome measures included time to union, need for additional procedures, time to return to work, disabilities of the arm, shoulder, and hand (DASH) questionnaire, Michigan Hand Questionnaire (MHQ) and Mayo wrist score (MWS).Time to union was determined by monthly radiographs and confirmed by a computerized tomographic (CT) scan done at 4 months. Results: Union was achieved in 85.7% of patients in group A and in 100% of patients in group B. Patients in group B showed a faster time to healing (2.3 ± 0.4 months vs 3.1 ± 0.7 months, p = 0.0001) and earlier return to work (10.4 ± 2.2 vs 15.1 ± 2.9, p = 0.0001). There were no significant differences in patient-rated outcomes scores between the two groups at final follow-up. Conclusions: Internal fixation alone is effective in treating subacute proximal pole scaphoid fractures. GPRP application improves bone healing and functional recovery. Level of Evidence: Level III (Therapeutic).

Is it time to resume elective knee arthroplasty surgery? A multidisciplinary experience in a Sardinian center during the SARS-CoV-2 pandemic.

Background: Starting in January 2020, the SARS-CoV-2 pandemic caused changes in the nation's health systems. The hospital's reorganization led to a near-total stop of non-urgent, elective surgeries across all specialties, including hip and knee arthroplasty. However, in May 2020, a gradual elective surgery restarting was possible. Considering the risk of COVID-19 infections, the European Knee Associates suggest the need to implement specific protocols for a safe return to orthopaedic elective surgery. Methods: A retrospective analysis regarding all patients who underwent primary knee arthroplasty (TKA) between March 1st and October 1st, 2020 using an institutional database was performed. The study time was divided into 2 periods: Pandemic (from March 2020 to May 2020), Post Pandemic (from June 2020 to October 2020). A specific protocol was designed to safeguard the health of patients and healthcare workers during the SARS-CoV-2 pandemic. Results: A total of 147 patients underwent total knee replacement surgery in the analyzed period. The mean surgical time was 77.6 (+/-18.9). The intraoperative mean blood loss was 54 (+/-28) ml. The mean hospital stay was 3-4 days. Among the treated patients no case of COVID-19 infection was observed. Conclusion: The use of our protocol, developed ad hoc for the management of elective orthopedic patients, allowed the restart of elective orthopedic surgery in a safe and reproducible way with an average increase of 374% on surgical activity between the pandemic and post-pandemic periods without record cases of contagion among the treated patients.

Elastic stable intramedullary fixation using epibloc versus crossed kirschner wires fixation for distal forearm fractures in children: A retrospective analysis.

Background: Childrens' distal forearm fractures (DFFs) could be treated conservatively with closed reduction and immobilisation, but post-reduction displacements often occur. Displaced DFF should be surgically fixed, to avoid further displacement. Nevertheless, immobilisation after surgery is recommended. Epibloc system (ES), a system of stable elastic nail fixation, is widely used to stabilise adults extra-articular distal radius fractures, with advantages to not requiring post-surgical immobilisation. The present investigation represents a retrospective analysis of paediatric patients with DFF treated with ES applied with a minimal technical variation, to fix both ulna and radius fractures using a unique device. Materials and Methods: A retrospective analysis was performed on 44 children (age 6-11 years) who underwent closed reduction and internal fixation because of DFF (both ulna and radius). Group A (21 patients): ES fixation. Group B (23 patients): K-wires and short arm cast fixation. The primary outcome was the subsistence of reduction monitored through X-rays. The secondary outcome was the measurement of active range of motion (AROM) and the time of recovery. Results: No differences were observed comparing Group A and B in terms of the maintenance of reduction (P > 0.05). Seven days after the implant removal, patients in Group A reached significantly better results compared to patients in Group B in terms of AROM (P < 0.05). No differences were revealed in terms of complications between the two groups. Conclusion: ES applied with a minimal technical variation is safe and effective in treating distal ulna and radius fractures, with minimal requirement of post-surgical rehabilitation.

Three-Dimension-Printed Custom-Made Prosthetic Reconstructions in Bone Tumors: A Single Center Experience.

Bone can be affected by different neoplastic conditions. Limb salvage surgery has become the preferred treatment strategy for most malignant tumors of the extremities. Advanced 3D printing technology has transformed the conventional view of oncological surgery. These types of implants are produced by electron beam melting (EBM) technology by sintering titanium powder in a scaffold shape designed following a project designed from HRCT and MRI. The aim of our study was to evaluate the outcomes and the mid-term follow-up of a population treated with 3D-printed custom-made prosthesis implantation in major oncological bone resection or after failure of primary implants. The primary outcome was the general patient satisfaction one year after surgery. The secondary outcomes were: mortality rate, treatment related complication rate, functional and clinical outcomes (KPS, ADL and IADL). Eight patients were included, five females and two males, with a mean age of 50.3 (±23.72) years at the surgery. The enrolled patients reported a mean satisfaction rate after surgery of 7.38 (±2) where 10 was the maximum value. There were no changes between pre- and postoperative mean KPS (81.43 +/−10.69). Mean preoperative ADL and IADL score was in both cases 4.86 (±1.07), while postoperative was 5 (±0.82), with a delta of 0.13 (p > 0.05). Custom-made prosthesis permits reconstructing bone defects caused by large tumor resection, especially in anatomically complex areas, restoring articular function.

Single-Level Anterior Cervical Discectomy and Interbody Fusion: A Comparison between Porous Tantalum and Polyetheretherketone Cages.

Background: Anterior cervical discectomy and interbody fusion (ACDF) may be performed with different kinds of stand-alone cages. Tantalum and polyetheretherketone (PEEK) are two of the most commonly used materials in this procedure. Few comparisons between different stand-alone implants for ACDF have been reported in the literature. Methods: We performed a comparison between patients who underwent ACDF with either a porous tantalum or a PEEK stand-alone cage, in two spine surgery units for single-level disc herniation. Clinical outcome [Neck Disability Index (NDI), Visual Analog Scale (VAS) for pain, Short Form-36 (SF-36)] and radiological outcome (lordosis, fusion and subsidence) were measured before surgery and at least one year after surgery in both groups. Results: Thirty-eight patients underwent ACDF with a porous tantalum cage, and thirty-one with a PEEK cage. The improvement of NDI and SF-36 was significantly superior in the PEEK group (p = 0.002 and p = 0.049 respectively). Moreover, the variation of the Cobb angle for the cervical spine was significantly higher in the PEEK group (p < 0.001). Conclusions: In a retrospective analysis of two groups of patients with at least one year of follow-up, a stand-alone PEEK cage showed superior clinical results, with improved cervical lordosis, compared to a stand-alone porous tantalum cage. Further studies are needed to confirm these data.

Posterior Percutaneous Pedicle Screws Fixation Versus Open Surgical Instrumented Fusion for Thoraco-Lumbar Spinal Metastases Palliative Management: A Systematic Review and Meta-analysis.

Background: Surgical palliative treatment of spinal metastases (SM) could influence the quality of life (QoL) in cancer patients, since the spine represents the most common site of secondary bony localization. Traditional open posterior instrumented fusion (OPIF) and Percutaneous pedicle screw fixation (PPSF) became the main surgical treatment alternatives for SM, but in Literature there is no evidence that describes the absolute superiority of one treatment over the other. Materials and Methods: This is a systematic review and meta-analysis of comparative studies on PPSF versus OPIF in patients with SM, conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The outcomes of interest were: complications, blood loss, infections, mortality, pain and also the Quality of Life (QoL). Results: There were a total of 8 studies with 448 patients included in the meta-analyses. Postoperative complications were more frequent in OPIF (odds ratio of 0.48. 95% CI, 0.27 to 0.83; p= 0.01), PPFS was associated with blood loss (odds ratio -585.70. 95% IC, -848.28 to -323.13.69; p< 0.0001) and a mean hospital stay (odds ratio -3.77. 95% IC, -5.92 to -1.61; p= 0.0006) decrease. The rate of infections was minor in PPFS (odds ratio of 0.31. 95% CI, 0.12 to 0.81; p= 0.02) whereas the occurrence of reinterventions (0.76. 95% CI, 0.25 to 2.27; p= 0.62) and the mortality rate was similar in both groups (odds ratio of 0.79. 95% CI, 0.40 to 1.58; p= 0.51). Finally, we also evaluated pre and post-operative VAS and the meta-analysis suggested that both techniques have a similar effect on pain. Discussion and Conclusion: The PPSF treatment is related with less complications, a lower rate of infections, a reduction in intraoperative blood loss and a shorter hospital stay compared to the OPIF treatment. However, further randomized clinical trials could confirm the results of this meta-analysis and provide a superior quality of scientific evidence.