Complex pelvic and spinopelvic injuries present significant surgical challenges, often requiring intricate reduction and stabilization. Minimally invasive techniques reduce soft-tissue complications but are technically demanding. This study evaluates the safety, feasibility, and outcomes of using robotic-assisted navigation for spinopelvic fixation in complex trauma and presents our workflow and technique for these cases. A retrospective review was conducted of patients who underwent robotic-assisted spinopelvic fixation for traumatic pelvic and spinopelvic injuries at a single tertiary center. Outcome measures included reduction adequacy, operative time, radiation exposure, hardware failure, and postoperative complications. Sixteen patients (81

BACKGROUND:Percutaneous sacroiliac (SI) screw fixation is a widely used technique for stabilizing sacral fractures but is considered technically demanding due to complex pelvic anatomy and proximity to neurovascular structures. Conventional fluoroscopy-guided methods are associated with a relatively high risk of screw misplacement and considerable radiation exposure to patients and staff. Robotic-assisted navigation systems have been introduced to enhance screw accuracy and reduce radiation exposure. The aim of this study was to assess the efficiency, safety, and accuracy of sacroiliac screw fixation using a robot-assisted method compared with a conventional freehand technique. METHODS:Medical records of patients treated with sacroiliac screw fixation for sacral fractures at a single Level 1 trauma center between December 2014 and August 2025 were retrospectively analyzed. Patients were divided into robotic-assisted and freehand fluoroscopy-guided groups for comparative analysis. Primary outcomes were intraoperative radiation exposure and operative time; secondary outcomes included screw position accuracy and complications. Statistical analysis was performed with significance set at p < 0.05. RESULTS:Twenty-five patients (mean age: 57.7 ± 22.4 years) were included; 15 in the robotic-assisted and 10 in the conventional fluoroscopy-guided groups. A total of 47 SI-screws were inserted: 29 in the robotic group and 18 in the conventional group. Operative times were comparable between groups (47.1 ± 16.3 min and. 45.1 ± 30.0 min, respectively; p = 0.85). Compared to conventional fluoroscopy, robotic assistance was associated with reduced fluoroscopy time (55.1 ± 23.1 vs. 181.1 ± 104.4 s, p=0.053) and higher screw placement accuracy (94 % vs. 62 %, p = 0.06), although these did not reach statistical significance. No major intraoperative complications occurred. CONCLUSION:Robotic-assisted navigation in sacroiliac screw insertion can potentially lower radiation exposure and improve screw placement accuracy compared to conventional techniques, without prolonging surgical time. These findings support robotic guidance as a safe and potentially more precise alternative for sacral fracture fixation. Further prospective studies should be performed to evaluate the possible benefits of robotic assisted sacroiliac screw fixation.

Background: The prevalence of sacral insufficiency fractures resulting from minor trauma has been on the rise in parallel with the globally aging population. For similar injuries typical to the elderly population, such as hip fractures, surgery and early mobilization have been shown to improve postoperative mortality and morbidity rates. As such, there has been a recent increase in the literature in studies advocating for early surgical fixation for sacral insufficiency fractures. However, traditional fluoroscopic techniques are technically demanding and bear an inherent complication risk even in experienced hands. Robotic-assisted surgery has emerged as a promising technological advancement in spinal and pelvic surgery. We share our experience with this surgical technique. Methods: We conducted a retrospective analysis of five consecutive patients with sacral insufficiency fractures who failed non-operative management. Using the Mazor X robotic system, patients underwent CT-planned, guided placement of fenestrated sacroiliac screws followed by cement augmentation. Primary outcomes included surgical time, radiation exposure, complications, and mobilization, with a minimum three-month follow-up. Results: The cohort consisted of five females with a mean age of 78 years. The mean operative time was 36 min (15-47), and the median fluoroscopy count was 13 shots (6-19). All patients reported significant pain relief and achieved successful mobilization on postoperative day 1. No operative or postoperative complications were recorded. Conclusions: This pilot study suggests that robotic-assisted percutaneous sacroiliac fixation with cement augmentation is a safe, efficient, and minimally invasive approach for the treatment of sacral insufficiency fractures. The precision of the robotic system facilitates stable fixation, providing immediate pain relief and early mobilization with a favorable complication profile. Further studies should be performed to verify these findings.

Background/Objectives: Long-term bisphosphonate (BP) therapy is an effective treatment for osteoporosis but has been associated with rare complications such as atypical femoral fractures (AFFs). Emerging reports suggest that similar insufficiency fractures may also occur in other skeletal sites, including the lumbar pedicles. This study reports two rare cases of isolated bilateral lumbar pedicle stress fractures in patients on prolonged BP therapy. Along with a structured literature review, the objective was to evaluate whether diagnostic criteria derived from those used for AFFs may apply to these atypical vertebral fractures. Methods: Two patients with osteoporosis and on long-term BP therapy diagnosed with isolated lumbar pedicle stress fractures were retrospectively analyzed. A structured literature review identified similar reported cases. All cases were evaluated using the 2010 American Society for Bone and Mineral Research AFF criteria to assess applicability to isolated pedicle stress fractures. Results: Both patients demonstrated bilateral lumbar pedicle fractures without vertebral body involvement. One was treated conservatively; the other underwent robotic-assisted percutaneous pedicle screw fixation with documented fracture healing at six months. The literature review identified eight similar cases of isolated pedicle fractures in patients on prolonged BP therapy. Clinical course and imaging findings demonstrated stress-type features analogous to AFFs. The proposed AFF-based diagnostic criteria for pedicular insufficiency fractures were found to be applicable to all ten patients. Conclusions: Isolated bilateral pedicle stress fractures may represent a spinal analog of AFFs. Based on shared clinical and imaging features, we propose preliminary diagnostic criteria for atypical pedicular insufficiency fractures. Increased awareness and standardized criteria may aid in early diagnosis and reporting, encouraging further studies on this rare spinal entity.

Background/Objectives: Myopathies are acquired or genetic muscle diseases causing weakness and wasting, leading to poor posture, impaired coordination, reduced daily function, and scoliosis. The objective of this ambispective study was to compare clinical, radiological, and functional outcomes of patients with myopathic scoliosis treated surgically or non-surgically. Methods: We identified 118 patients (55% male) with myopathy and scoliosis from ALYN Rehabilitation Hospital’s database (1990–2022). Mean age at first visit was 5.45 ± 5.27 years. Seventeen (14%) underwent scoliosis surgery; others were managed non-surgically. Due to unbalanced group sizes, comparative group analyses used propensity score matching (15 surgical, 30 non-surgical patients). Retrospective data included demographics, medical history, respiratory and mobility status, Cobb angle (CA), pelvic obliquity (PO), and surgical details when applicable. Prospective telephone interviews were conducted including SRS-22r Quality of Life (QoL), WHO-QoL, and Functional Independence Measure for Children (WeeFIM). Results: Longitudinal analysis showed significant or near-significant worsening over time in CA (p = 0.03) and PO (p = 0.08), regardless of treatment type but no significant difference between surgical and non-surgical groups in progression rates. Interview data, for 7 surgical and 6 non-surgical patients, revealed that surgical patients reported higher overall QoL, FIM, and SRS-22r self-image scores, but lower scores for SRS-22r pain, general function, and activity levels. Conclusions: Existing research and this study suggest that despite surgical risks, scoliosis correction in neuromuscular conditions generally leads to improved QoL. Findings highlight the complexity of surgical decision-making for myopathic scoliosis, where medical risks must be weighed against potential long-term functional and QoL outcomes.

STUDY DESIGN:This study represents a preclinical cadaveric study using a optic 3D spine navigation system. OBJECTIVES:In this study, our objective is to evaluate the feasibility and accuracy of real-time imaging and navigation for thoracolumbar pedicle screw placement in 8 cadavers using optical imaging technology, employing the PathKeeper System, a 3D spine navigation system. SUMMARY OF BACKGROUND DATA:To evaluate the feasibility of the optic navigation system, 90 pedicle screws were placed in 8 cadavers using the system. Real-time tracking was monitored throughout the screw placement process. METHODS:This preclinical study utilized AI-driven, radiation-free real-time optical navigation to guide pedicle screw placement in the thoracolumbar spine of 8 cadavers. To assess the system's real-time tracking resistance to spinal motion, the cadavers were repositioned to alter the conditions between vertebrae, and extensive dissection and spinal osteotomies were performed throughout the procedure. The accuracy of screw placement, assessed using the Gertzbein-Robbins scale, was confirmed by an independent radiologist through postoperative CT imaging. RESULTS:Placement of 90 pedicle screws between T1 and L5 vertebrae was achieved by 5 different surgeons using the optic imaging system. The accuracy rate of pedicle screw placement using real-time tracking and imaging across the full range of lumbar and lower thoracic vertebrae was 100% in all cases, including for surgeons without prior experience with use of the navigation system. Postoperative CT verification by an independent radiologist confirmed that 100% of the screws in all cases were positioned with Gertzbein-Robbins grades of A or B. CONCLUSION:PathKeeper optical spine navigation system demonstrated both feasibility and 100% accuracy in the placement of 90 pedicle screws in 8 cadavers. The system's user-friendly surgery planning software also supports a swift learning curve. Optical navigation, an emerging new technology may provide a safe radiation free spine surgery solution.

Purpose: To identify and characterize events of deterioration in intraoperative neuromonitoring data during correction procedures for thoracic and lumbar abnormal spinal curvature in young patients. Methods: Records of 1,127 cases were retrospectively reviewed to identify events with deterioration of the neuromonitoring data. General etiological and demographic variables were summarized, and neuromonitoring events were studied and characterized. Results: Adolescent idiopathic cases were associated with female dominance and older age. Nonadolescent idiopathic cases were associated with a higher rate of neuromonitoring events. The neuromonitoring events evolved during the different procedural stages, were primarily reflected in the motor-evoked potential data and affected a range of neural structures to varying degrees. Most of the events were resolved, partially or completely, following a corresponding intervention by the surgical team, before the end of the procedure. Significant immediate weakness of the lower extremities was demonstrated in patients with unresolved neuromonitoring events, most of them were nonadolescent idiopathic patients. Conclusions: Neurophysiological monitoring enables the intraoperative assessment of the integrity of neural pathways and allows the detection of surgery-related impending neural injuries. Neuromonitoring contributes to intraoperative decision making, either when data are uneventful and allow confident continuation or when data deteriorate and lead to corresponding intervention. Further awareness should be paid to the vulnerable characteristics of the patient, surgery course, and neuromonitoring data. Proper interpretation of the neuromonitoring data, together with corresponding intervention by the surgeon when necessary, has the potential to reduce postoperative neurological insults and improve clinical outcomes.

Background Workforce shortage in healthcare and particularly in physicians poses a threat to healthcare delivery and its quality. In comparison to other OECD countries, Israel currently has a small number of medical graduates relative to its number of physicians, naturally emphasizing the importance of ensuring that this population chooses to remain in medicine. Understanding what is most important to medical students can help improve working conditions in residency. Such information is particularly needed to facilitate policy planning that will encourage the next generation of physicians to specialize in medical fields that are experiencing shortages. We hypothesized that between 2009/2010 and 2020, there were significant changes in medical students' preferences regarding their considerations for choosing a medical specialty. Methods We compared cross-sectional data from questionnaire-based surveys of 5th year medical students performed in 2009–2010 and 2020 at two Israeli universities. Results Of the 335 medical students who responded (237 and 98 in 2009/2010 and 2020, respectively) those in 2020 were 2.26 less likely vs. those in 2009/2010, to choose a residency for its high-paying potential ( P < 0.05), and had significantly more interest in residencies with greater teaching opportunity (98.8% vs 82.9%, P < 0.05), increased responsibility and chances to make clinical decisions on their own (67.9% vs 51.6%, P < 0.05). Criteria important to both the 2009/2010 and 2020 students were choosing a bedside specialty (70.2%vs 67.9%, NS), and an interesting and challenging specialty (95.2%v s 91.3%, NS). Conclusions These results partially supported our hypothesis that medical students' preferences have changed over the years, though there are fundamental factors that apparently reflect medical students’ nature that do not change over time.

Study design Retrospective cohort study with a cross-sectional comparison. Objectives To assess sexual function and experience in adult women who had scoliotic correction for adolescent idiopathic scoliosis (AIS). Methods Women ages 18–40 years with a history of scoliosis, who were braced or underwent uncomplicated posterior scoliosis correction for AIS, followed for two years or more since treatment were included. Sexual function was assessed using the Female Sexual Distress Scale-Revised (FSDS-R) and the Female Sexual Function Index (FSFI) questionnaires. Participants’ scores were compared to those of a control group consisting of age-matched healthy women. Results Of 115 women who responded to the questionnaires, 40 (35%) had surgical treatment (mean age 25.1; range 19–35 years; mean time since surgery 8.2 years; range 3–12 years) and 35 (30%) were braced (mean age 23.3; range 18–27 years; mean time since treatment 3.6 years; range 3–5 years). The control group consisted of a cohort of 40 (35%) aged-matched healthy women. According to the FSDS-R, significantly more women with scoliotic correction for AIS reported sexual distress compared to healthy controls (25% vs 12%, respectively), and the difference in the total mean scores (7.05 vs 5.34, respectively), was significant (P < .001). Additionally, the mean overall FSFI score for scoliotic-corrected women was 24.2 (range 17.5–29.1) within the pathological range (<26.55) of sexual dysfunction. Conclusions High rates of sexual distress and dysfunction were reported in women with a history of AIS, thus, there appears to be long-term consequences years after deformity correction by brace or surgical correction.

Purpose: To identify characteristics associated with higher incidence of intraoperative deterioration of neurophysiological potentials related to spinal tracts in cervical spine surgeries. Methods: Electrophysiological raw data and neurophysiological case reports of 1,611 patients from multiple medical centers, who underwent cervical spine surgery for decompression and/or fusion, were retrospectively reviewed. Patient-related and procedure-related variables were identified and analyzed for correlation with intraoperative neurophysiological event of the spinal tracts. The neurophysiological events were analyzed for identification of collective characteristics. Results: The study cohort presented consistent dominancy of male over female patients (67% vs. 33%). Intraoperative deterioration of spinal tract–derived potentials was noted in 10.5% of the total cases, which was not correlated with gender, age, or indication of the surgery. Higher incidence of neurophysiological events was noted in patients with impaired baseline of motor evoked potentials from the thenar muscle (P = 0.01) or somatosensory evoked potentials of the posterior tibial nerve (P = 0.0002). Procedures of circumferential approach or procedures that involved ≥3 spinal levels demonstrated higher incidence of neurophysiological events as well (P = 0.0003 and 0.001, respectively). Conclusions: Patients with deteriorated neurophysiological baseline and procedures of extensive intervention are at higher risk of intraoperative neurophysiological event in cervical spine surgery. Inclusion of intraoperative neurophysiological monitoring should be encouraged in complicated cases of cervical spine surgeries.

Introduction In the past decades, there has been an increasing interest in quality of life assessment after treatment of adolescent idiopathic scoliosis. Scoliosis affects young patients many of them women that deal with the scoliosis and surgical treatment for the rest of their life. The effect of scoliosis correction on sexual function has yet to be assessed. The female sexual function index (FSFI) is a validated tool for the assessment of sexual function in women. Materials and Methods Women (over the age of 18) under the age of 40, who underwent uncomplicated posterior scoliosis correction for idiopathic adolescent scoliosis, were assessed for sexual function via the FSFI. The scores retained were compared to the general population data in the following five categories: desire, sexual arousal, lubrication, orgasm, and satisfaction and pain. Results A total of 22 women responded to the questioner. The average age was 28 (range: 19 to 38). Time from surgery was 8.2 years (range: 2 to 17 years). All patients underwent uncomplicated posterior spine fusion, without the need of secondary interventions. The Cobb angle correction in the surgery was 55 degrees (range: 40 to 70). The average FSFI score was 24.2 (range:17.5 to 29.1) (normal score over 26.5). Patients scored within the normal range in sexual desire, pain during intercourse, and lubrication. A decreased score was noted in sexual arousal, orgasms, and satisfaction, when compared to normal population values. Conclusion Female patients, who underwent correction of scoliosis due to AIS, have a decreased sexual function, many years after the surgery when compared to the general population. This is due to a decreased arousal, orgasms, and a decreased sexual satisfaction. A distinction still needs to be made if this is due to the scoliosis or the correction. I confirm having declared any potential conflict of interest for all authors listed on this abstract Yes Disclosure of Interest None declared

Introduction: Understanding ” what is most important ” to medical-students can help improve residence learning and working conditions. Such information is needed to facilitate policy planning that will encourage the next generation of physicians to specialize in medical-fields that are experiencing shortages. The hypothesis was, there are significant changes in medical students’ preferences, regarding the considerations for choosing a medical specialty in 2020 as compared to students a decade earlier. Methods: A time comparison cross-sectional study of 5 -year medical students from two universities took place in 2010 and 2020. A questionnaire was used to examine various aspects of the specialty selection process. Results : 335 medical-students answered the survey (237 and 98 in 2010 and 2020, respectively). Medical students in 2020 in comparison to 2010, were 2.26 time less likely to choose a residency because of its potential for a high income (P<0.05), had significantly more interest in residencies with greater teaching (98.8% vs 82.9%, P<0.05) and increased responsibility/chance to make clinical decisions on their own (67.9% vs 51.6%, P<0.05). There were criteria which were important to both the 2010 and 2020 students, such as, choosing a bedside specialty (70.2%vs 67.9%, NS), an interesting and challenging residency (95.2%v s 91.3%, NS) and interest in a specialty that involved working in the operating room (29.8% vs 32.6%, NS). Conclusions: These results reinforce the idea of avoiding stereotypes based on the generational cohort and the importance of exploring the needs and motivations of medical students. Notably, we found that the 2020 medical-students were more interested than their predecessors in residencies with much resident teaching and more responsibility/making clinical decisions on their own. In addition, we found that selection criteria such as, importance of choosing a specialty that one finds interesting and challenging, are universal over time.

BACKGROUND CONTEXT Occult bacteria have been linked to deep and chronic infections in spine surgery. These organisms are commensal to dermal and deeper tissue layers, including the intervertebral disc and bone. We hypothesize that standard surgical skin preparation nor preoperative antibiotics properly access and eradicate these organisms prior to primary spine surgery. These organisms can potentially adhere to the biofilm surrounding the hardware and limit bone formation. PURPOSE To determine the colonization rate of occult bacteria in the superficial and deep tissue layers of healthy patients undergoing primary instrumented lumbar spine surgery. STUDY DESIGN/SETTING This prospective, consecutive cohort of patients undergoing primary lumbar spine surgery at a single tertiary center. All patients met the inclusion/exclusion criteria which included between the ages of 18 and 80, undergoing a posterior approach with pedicle screw instrumentation with no evidence of a prior or current fracture, trauma, tumor, or an active systemic or local infection. Patients were also excluded if they were immunosuppressed or had received prior surgery at any lumbar level with hardware. This study was approved by our institutional review board and ethics review panel. PATIENT SAMPLE Fifty-four patients. OUTCOME MEASURES Culture swabs, fusion rates, revision rates. METHODS All patients received preoperative antibiotics and skin preparation. Culture samples were subsequently obtained from the superficial skin, dermal wound-edge following incision, hypodermis and the vertebral pedicle prior to instrumentation implantation. Control culture samples were taken from scalpel, tap and suction prior to incision. The primary outcome was the rate of positive culture samples from the various layers traversed during standard surgical spine exposure. Clinical outcomes of fusion status and revision rate were collected. RESULTS A total of 525 culture samples were obtained, and samples were positive in 33.3% of patients (18/54). Culture-positive patients had on average 3.1 positive samples per case. Superficial skin samples were positive in 13.0% (n=7), dermal layer samples in 16.7% (n=9), hypodermis samples in 13.0% (n=7), and vertebral samples in 20.4% (n=11) of cases. All control samples taken were culture-negative. C. acnes was the most common organism isolated, in 83.3% of culture-positive cases. Significantly more males were culture-positive than females. Patients with positive cultures were treated with antibiotics. At one-year postoperative, patients in culture-positive group had similar fusion rates to culture-negative groups. However, delayed fusion was observed at a higher rate in the culture-positive group. CONCLUSIONS Occult bacteria was detected in one-third of patients undergoing primary instrumented posterior spine surgery. Deep culture samples of the vertebral pedicle were more often positive than dermal layer samples. The data collected supports our hypothesis that occult bacteria persist in the skin and deeper tissue layers regardless of the efforts made by preoperative skin preparation and prophylactic antibiotics. The clinical sequela for culture-positive patients, although addressed perioperatively, was a higher incidence of delayed fusion. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Abstract Background Spinal trauma patients treated in a specialized hybrid operating room (OR) using two robotic systems communicating during surgery. Methods Retrospective review of patients with thoracolumbar or sacral fractures who underwent surgical fixation between Jan 2017 to Jan 2020 with robotic-guided percutaneous pedicle screw insertion in the specialized hybrid OR with Robotic flat panel 3D C-arm (ArtisZeego) for intraoperative interventional imaging connected with the robotic-guidance platform Renaissance (Mazor Robotics). Results Twenty eight surgeries were performed in 27 patients; 23 with traumatic spinal fractures, 4 with multi-level thoracolumbar compression fractures due to severe osteoporosis. Average patient age 49 (range 12–86). Average radiation exposure time 40 s (range 12–114 s). Average radiation exposure dose 11,584 ± SD uGym2 (range 4454–58,959). Lumber levels operated on were between T5 and S2 (shortest three vertebras and longest eight vertebras). 235 (range 5–11) trajectories were performed. All trajectories were accurate in all cases percutaneous pedicle screws placement was correct, without breach noted at the pedicle in any of the cases. No major complications reported. In all cases, follow-up X-rays showed adequate fracture reduction with restoration. Conclusions Merging of surgical robotics technologies increases patient safety and surgeon and patient confidence in percutaneous spine traumatic procedures.

INTRODUCTION:Unstable fractures in sick or elderly patients are on the rise. These patients who are at high risk for surgery present a challenge for surgeons and anesthesiologists. In patients with American Society of Anesthesiologists (ASA) scores 3 to 4, the risk is even higher because of the high rate of intraoperative complications. METHODS:All patients with ASA scores 3 to 4 who presented with unstable fractures of the spine to a level-one trauma center were assessed, and they underwent awake spinal percutaneous fixation, with mild sedation and local anesthesia. Demographics, radiology, and the outcome were collected. RESULTS:Nineteen patients were operated between the years 2019 and 2021. Average follow-up was 12 months (range 8 to 24 months); six patients were female and 13 males. The average age was 77.7 years; the ASA score was 3 to 4 in all patients. There were 10 extension-type injuries, six unstable burst injuries, two chance fractures, and one teardrop fracture. All patients underwent unilateral fixation, and just one patient underwent bilateral fixation; cement augmentation was done in 16 of the patients. No neurologic complication was observed. One case of infection presented 4 months after surgery. All patients were discharged ambulating. CONCLUSIONS:Awake fixation in extreme cases is safe and feasible; a dedicated team including an anesthesiologist and radiologist is needed to treat these cases safely and quickly.

A nulliparous previously healthy pregnant woman who suffered from postpartum spinal epidural abscess due to Streptococcus agalactiae which probably evolved during delivery.

Study Design: This is a prospective observational study. Objective: The aim of this study is to determine the rate of occult infection after instrumented spine surgery in presumed aseptic patients. Summary of Background Data: The reported incidence rate of delayed/occult infection determined by positive culture swabs after instrumented spine surgery in prospective studies is 0.2%-6.9%. However, this rate may be higher as delayed infections are challenging to diagnose. Fever can be absent and inflammatory markers are often normal. If indolent organisms exist in low concentrations surrounding the instrumentation, these organisms can possibly avoid detection and disrupt bone formation leading to instrumentation loosening, pain generation, and/or failure of a solid fusion. Materials and Methods: This study included 50 consecutive presumed aseptic patients undergoing a posterior revision requiring removal of instrumentation at least 6 months following their index procedure. Common markers of infection were examined preoperatively. Multiple culture swabs were taken directly from the removed instrumentation and cultured for 14 days. Results: Of the 50 patients, 19 (38%) were culture-positive (CP) for bacteria upon removal of their instrumentation, with 14 patients (28%) having >= 2 positive specimens of the same organism. The average length of time between the index procedure and the revision surgery was 4.55 years (range: 0.53-21 y). Polymicrobial infections were found in 26% (5/19) of CP patients. The most prevalent microorganism found was Propionibacterium acnes, in 63% (12/19) of CP patients. There was no significant difference between CP and culture-negative patients regarding preoperative markers for infection, age, or length between index and revision procedures. Conclusions: The results of this study indicate a positive culture rate of 38% in presumed aseptic patients who had previously undergone instrumented spine surgery. These results are consistent with other retrospective studies and are >6 times greater than any previous prospective study utilizing culture swabs.

Abstract. Objectives:. Sacral fractures that require fixation are a challenge for the orthopaedic surgeon. Due to anatomical consideration, implant insertion is not risk free, and requires a steep learning curve. A robotic system has been successfully used in pedicle screws insertion and can be also used for iliosacral screws. The aim of the study was to demonstrate the use of the robot in the treatment of unstable sacral fractures. Design:. Retrospective case series. Setting:. An academic level I trauma center. Patients:. Fourteen patients with sacral fractures were eligible for robotic assisted treatment. These included 9 high-energy fractures, 4 osteoporotic fractures, and 1 pathological fracture. Intervention:. Fixation constructs included iliosacral screws, transiliac screws, lumbopelvic fixation, sacroplasty, or a combination of the above techniques. A Renaissance robot was mounted on a multidirectional bridge that was attached to the patients spine and implant trajectories were planned either on preoperative or intraoperative 3D scans. Guide wires were inserted percutaneously and screws were placed subsequently. Main outcome measurements:. Accuracy of implant placement, operating room and fluoroscopy time. Results:. Mean patient age was 36 (17–84), and number of screws, including iliosacral and pedicular ranged 1–14 per patient (average 4.25). Mean operative time was 150 minutes (range 90–300). Average fluoroscopic time was 18 seconds (7–42) for 2D and 40 seconds (12–72) for 3D imaging. All fractures healed, no hardware failure was observed. All hardware was always within bony confines, and no procedure-related neurological deficits were observed. Conclusion:. Robotic assisted fixation of sacral fracture is a safe and reproduceable method, allowing precise and accurate implant placement.

Lipid nanoparticles are used widely as anticancer drug and gene delivery systems. Internalizing into the target cell is a prerequisite for the proper activity of many nanoparticulate drugs. We show here, that the lipid composition of a nanoparticle affects its ability to internalize into triple-negative breast cancer cells. The lipid headgroup had the greatest effect on enhancing cellular uptake compared to other segments of the molecule. Having a receptor-targeted headgroup induced the greatest increase in cellular uptake, followed by cationic amine headgroups, both being superior to neutral (zwitterion) phosphatidylcholine or to negatively-charged headgroups. The lipid tails also affected the magnitude of cellular uptake. Longer acyl chains facilitated greater liposomal cellular uptake compared to shorter tails, 18:0 > 16:0 > 14:0. When having the same lipid tail length, unsaturated lipids were superior to saturated ones, 18:1 > 18:0. Interestingly, liposomes composed of phospholipids having 14:0 or 12:0-carbon-long-tails, such as DMPC and DLPC, decreased cell viability in a concertation dependent manner, due to a destabilizing effect these lipids had on the cancer cell membrane. Contrarily, liposomes composed of phospholipids having longer carbon tails (16:0 and 18:0), such as DPPC and HSPC, enhanced cancer cell proliferation. This effect is attributed to the integration of the exogenous liposomal lipids into the cancer-cell membrane, supporting the proliferation process. Cholesterol is a common lipid additive in nanoscale formulations, rigidifying the membrane and stabilizing its structure. Liposomes composed of DMPC (14:0) showed increased cellular uptake when enriched with cholesterol, both by endocytosis and by fusion. Contrarily, the effect of cholesterol on HSPC (18:0) liposomal uptake was minimal. Furthermore, the concentration of nanoparticles in solution affected their cellular uptake. The higher the concentration of nanoparticles the greater the absolute number of nanoparticles taken up per cell. However, the efficiency of nanoparticle uptake, i.e. the percent of nanoparticles taken up by cells, decreased as the concentration of nanoparticles increased. This study demonstrates that tuning the lipid composition and concentration of nanoscale drug delivery systems can be leveraged to modulate their cellular uptake.

INTRODUCTION:Regenerative medicine research has evolved significantly in recent years. There is a great un-met clinical need for developing new treatments that will induce regeneration of injured skeletal tissues in cases such as large bony defects caused by trauma or tumor resection, articular cartilage defects and torn or degenerate tendons and ligaments. Except for bone that can regenerate small defects, all other skeletal tissues do not hold the natural capability for regeneration after injury and rather form a less functional scar tissue. In order to induce tissue regeneration, it is now believed that three crucial elements must reach the injured zone: a) multipotent cells that can rapidly proliferate and differentiate to form the injured tissues, such as mesenchymal stem cells for skeletal tissues; b) extra-cellular matrix that will support the newly built tissues, and c) the correct molecular signals. Using diverse research tools and expertise, our department focused its research on basic, translational and clinical solutions for injured and degenerative skeletal tissues. In this review we will describe our different research directions, from in-vitro cell cultures and animal models studies to human clinical trials.