Use Of Intraoperative Fluoroscopy Research Articles

Optimizing vestibular implant electrode positioning using fluoroscopy and intraoperative CT imaging

Purpose Vestibular implant electrode positioning close to the afferent nerve fibers is considered to be key for effective and selective electrical stimulation. However, accurate positioning of vestibular implant electrodes inside the semicircular canal ampullae is challenging due to the inability to visualize the target during the surgical procedure. This study investigates the accuracy of a new surgical protocol with real-time fluoroscopy and intraoperative CT imaging, which facilitates electrode positioning during vestibular implant surgery.Methods Single-center case-controlled cohort study with a historic control group at a tertiary referral center. Patients were implanted with a vestibulocochlear implant, using a combination of intraoperative fluoroscopy and cone beam CT imaging. The control group consisted of five patients who were previously implanted with the former implant prototype, without the use of intraoperative imaging. Electrode positioning was analyzed postoperatively with a high-resolution CT scan using 3D slicer software. The result was defined as accurate if the electrode position was within 1.5 mm of the center of the ampulla.ResultsWith the new imaging protocol, all electrodes could be positioned within a 1.5 mm range of the center of the ampulla. The accuracy was significantly higher in the study group with intraoperative imaging (21/21 electrodes) compared to the control group without intraoperative imaging (10/15 electrodes), (p = 0.008).Conclusion The combined use of intraoperative fluoroscopy and CT imaging during vestibular implantation can improve the accuracy of electrode positioning. This might lead to better vestibular implant performance.

A standardised communication tool reduces radiation exposure associated with intraoperative fluoroscopy

BackgroundThe widespread use of intraoperative fluoroscopy in orthopaedic procedures has revolutionised surgical practice. However, there are risks associated with using ionising radiation. Efforts to reduce radiation exposure include low-dose imaging protocols and lead protective equipment. Current communication during fluoroscopic procedures can be inefficient and lead to excessive radiation exposure for patients and staff.AimsThis study aims to implement a communication tool with standardised commands to reduce radiation exposure in an Irish orthopaedic department.MethodsRadiation exposure was evaluated using dose-area product (DAP) measured in uGy/m2. A control group was recorded before implementing the communication tool. Training sessions were conducted and posters of the standardised commands were displayed. Feedback was collected from surgeons and radiographers via surveys. Statistical analysis was performed to compare pre- and post-intervention groups.ResultsA total of 673 surgical cases were included over 6 months. The post-intervention group showed a mean reduction in radiation exposure from 59.8 to 36.4 uGy/m2 (p < 0.011). Subset analyses revealed reduced radiation exposure for ORIF of the distal radius, ankle, humerus, and phalanges. Surgeons and radiographers recognised the need for improved communication and expressed willingness to learn the new tool.ConclusionsImplementation of a standardised communication tool effectively reduced patient and staff radiation exposure. It was also believed to have a positive effect on theatre staff morale. Incorporating a universal language tool into training programmes could be beneficial. Surgeons and radiographers provided several suggestions to improve the effectiveness and implementation of this tool into other units.

Intraoperative Use of Ultrasound for Assessing Cam Deformity and Cam Resection

The use of intraoperative fluoroscopy is standard among hip arthroscopist to evaluate and confirm the adequacy of cam resection in patients with femoroacetabular impingement syndrome. However, given the inherent limitations of fluoroscopy, additional intraoperative imaging, such as ultrasound, should be pursued. We offer a technique to measure alpha angles intraoperatively using ultrasound to determine adequate cam resection.

116. Intra-operative Use of Fluoroscopy for Guidance During Surgical Resection of Obstructive Vaginal Septum with Microperforation: a Case Report

116. Intra-operative Use of Fluoroscopy for Guidance During Surgical Resection of Obstructive Vaginal Septum with Microperforation: a Case Report

Intraoperative Fluoroscopy Radiation Using OEC 9900 Elite C-arm: Risk and Method for Decreasing Exposure.

The use of intraoperative fluoroscopy in surgery produces scattered radiation that can expose all operating room personnel to measurable and, in some cases, substantial radiation doses. The goal of this work is to assess and document potential radiation doses to various staff positions in a simulated standard operating room environment. Adult-sized mannequins wearing standard lead protective aprons were placed at seven positions around large and small BMI cadavers. Doses were recorded in real time at thyroid level with Bluetooth-enabled dosimeters for a variety of fluoroscope settings and imaging views. A total of 320 images were acquired, resulting in 2,240 dosimeter readings from the seven mannequins. Doses were compared to cumulative air kerma (CAK) calculations provided by the fluoroscope. There was a strong correlation between the CAK and the recorded scattered radiation doses ( P < 0.001). Radiation doses could be reduced by manipulating C-arm manual technique settings [e.g., turning off the automatic exposure control (AEC) and using pulse (PULSE) or low dose (LD) settings]. Staff position and patient size also affected the recorded doses. The highest radiation doses were recorded across all settings for the mannequin positioned immediately adjacent to the C-arm x-ray tube. The larger BMI cadaver generated greater scattered radiation than the smaller BMI cadaver for all views and settings. This work provides suggestions for reducing exposure to operating room personnel beyond standard techniques of reducing beam-on time, increasing the distance from the radiation source, and use of shielding. Simple changes in C-arm settings (turning AEC off, avoiding DS setting, use of PULSE or LD settings) can markedly reduce dose to staff.

Improved hip symmetry with an adjustable fluoroscopic grid during total hip arthroplasty.

The use of intraoperative fluoroscopy (IF) is common with direct anterior total hip arthroplasty (THA), however image distortion in IF may limit its usefulness. The supplementation of IF with an adjustable grid (AG) may provide consistently better accuracy in component placement. Therefore, the purpose of this study was to compare the accuracy, consistency, and surgical efficiency between IF only and AG supplementation. 2 cohorts were retrospectively evaluated, including 573 IF only patients and 211 AG patients having undergone unilateral THA between 2011 and 2018. Post-THA radiographic assessment was performed to evaluate the accuracy of component placement, with target placements for global hip offset (GHO) and leg-length differences (LLD) <10 mm and acetabular cup abduction of 45° (±10°). Accuracy and surgical efficiency were evaluated between groups and over time. The AG group had a significant greater percentage of components placed within the target zone compared to IF only for GHO (99.5%, 92.7%, p < 0.001), LLD (99.1%, 96.5%, p = 0.039) and abduction (99.5%, 96.3%, p = 0.009), with no difference in fluoroscopic time (p = 0.973). Over time, accuracy was significantly different in IF group for GHO (p = 0.008) and abduction (p = 0.002) and trended toward significance for LLD (p = 0.055). There were no significant differences over time for the AG group. The addition of an AG to IF significantly increased the accuracy of component placement during direct anterior THA. These results were consistent over 2 years of use and did not decrease surgical efficiency.

Feline Diaphyseal Fractures: Management and treatment options.

Cats frequently present with diaphyseal fractures, which require treatment in order to achieve a good return to function. These fractures often occur due to significant trauma; for example, as a result of road traffic accidents, high-rise syndrome and dog bite wounds. The first priority is to ensure the patient is systemically well before embarking on any specific surgical treatment of a fracture. Surgical management of diaphyseal fractures can be challenging due to the surgical approach for some bones being technically demanding, for example because of the presence of important neurovascular structures, and the small size of feline bones, which limits the choice of implant size and strength. Further, it may be difficult to visualise fracture alignment when using minimally invasive techniques, although the use of intraoperative fluoroscopy can aid with this, and malalignment can be common for some fracture repairs, particularly in cases where anatomical reconstruction is not possible. This review focuses on diaphyseal long bone fractures and aims to assist decision-making, with an overview of the management and treatment options available. Many textbooks and original articles have been published on aspects of managing fractures in small animals. The authors also provide recommendations based upon their own clinical experience.

Intraoperative Radiation Exposure to U.S. Podiatric and Medicine Surgery Residents Annually: How Much Are We Really Getting?

As the number and complexity of operative techniques taught at U.S. podiatric medicine and surgical residencies (PMSR) with the added credential in reconstructive rearfoot and ankle (RRA) surgery has continued to increase, so to has the use of intraoperative fluoroscopy. The purpose of the present prospective observational pilot study was to quantify and compare the shallow dose equivalent (SDE), deep dose equivalent (DDE), and lens of the eye dose equivalent (LDE) exposures for podiatric medicine and surgery residents at a single PMSR-RRA over 12 consecutive months. Shallow-dose equivalent, DDE, and LDE exposures (in millirems) were measured using Landauer Luxel dosimeters from July of 2018 to July of 2019. Dosimeters were exchanged monthly, and mean monthly/annual SDE, DDE, and LDE exposures were calculated and compared. Overall, residents averaged 19 operative cases per month and 222 per year. More than half (53%) required intraoperative fluoroscopy, for which a mini C-arm was used in most cases. Monthly SDE, DDE, and LDE exposures averaged 7.3, 9.3, and 7.0 mrem, respectively; whereas annual SDE, DDE, and LDE exposures averaged 87.3, 112, and 84 mrem, respectively. No significant monthly (P = 1.0, P = .70, and P = .74) or annual (P = .67, P = .67, and P = .33) differences were identified between residents. The annual SDE, DDE, and LDE for residents at a single PMSR-RRA were well below the recommended dose limits of 50,000 mrem/year (SDE), 5,000 mrem/year (DDE), and 15,000 mrem/year (LDE) set by the National Council on Radiation Protection. However, given that the stochastic effects from low levels of ionizing radiation are cumulative, not well studied long-term, and relate both to the degree and duration of exposure, mini-C arm fluoroscopy, radiation tracking, and use of personal protective equipment provide simple means for residents to reduce any long-term potential for risk.

Association between intraoperative computed tomography navigation system and incidence of surgical site infection in patients with spinal surgeries: a retrospective analysis

PurposeAlthough the use of intraoperative computed tomography (CT)-based navigation systems is unlikely to cause intraoperative contamination more than the use of intraoperative fluoroscopy, the association between intraoperative CT/navigation and surgical site infections (SSIs) remains unclear. We investigated the incidence of SSIs and the association between intraoperative CT/navigation and SSIs for spinal surgeries.MethodsOf the 512 patients who underwent spinal surgery between April 2016 and December 2020, 304 underwent C-arm intraoperative fluoroscopy and/or Medtronic O-arm intraoperative CT/navigation system. We investigated the incidence of SSIs in patients with four techniques; no intraoperative imaging C-arm only, O-arm only, and both O- and C-arm used. Multivariate logistic analyses were conducted using the prevalence of SSIs as the dependent variable. The independent variables were age, sex, and potential confounders including preoperative Japanese Orthopaedic Association (JOA) score, use of instrumentation, C-arm, and/or O-arm.ResultsThe incidence of the SSIs in patients with no imaging, C-arm only, O-arm only, and both modalities used was 1.9%, 7.3%, 4.7%, and 8.3%, respectively. There was no significant difference in the incidence of SSIs between the four techniques. Multivariate logistic analyses showed a significant correlation between the prevalence of SSI and JOA scores (odds ratio, 0.878; 95% CI 0.759–0.990) and use of instrumentation (odds ratio, 6.241; 95% CI 1.113–34.985), but not use of O-arm.ConclusionsThe incidence of the SSIs in patients with only O-arm used was 4.7%. Preoperative clinical status and use of instrumentation, but not use of the O-arm, were associated with SSIs after spinal surgeries.

The Use of Intra-Operative Brilliance Amplifier by Novice Surgeons to Improve Bone Tunnels Placement in Anterior Cruciate Ligament Reconstruction during Residency Curriculum: Useful or Not?

Objective: Our objective was to evaluate the contribution of the use of intra-operative fluoroscopy on tunnels positioning during the Anterior Cruciate Ligament (ACL) reconstruction. Methods: Between January 2020 and June 2022, a total of 8 ACL reconstructions by the Kenneth Jones (KJ) technique were performed by the same young orthopedic surgeon. Fluoroscopy was used intraoperatively to control the position of the guidewire before bone tunnels reaming. It was available for use in 4 cases who constituting the Fluoroscopy Assisted Reconstruction Group (FARG). Post operatively, we assessed on plane radiographs the interference screws position of the four patients constituting the Fluoroscopy Free Reconstruction Group (FFRG). The measurements of the two groups were compared and analyzed using a Wilcoxon matched-pairs signed-ranks test. Results: Of the 4 patients operated on using intra operative fluoroscopy, imaging allowed us to reposition the tibial and femoral guide wires before reaming in all cases (100%). In the second group (FFRG) of patients (n=4), operated without fluoroscopy, post-operative screw positions were in all patients (100%), more anterior in the tibia and more posterior in the femur than the usual position of bone tunnels of ACL reconstruction. Conclusion: In order to increase the precision of the bone tunnels placement during ACL ligamentoplasty in the hands of novice orthopedic surgeon, intraoperative fluoroscopy constitutes a considerable aid tool.

VISION ASSIT FOR AUTONOMOUS SURGERY ROBOT

The pedicle screw insertion has become the most exercised procedures in spine fusion surgery. It is performed to hold the vertebrae of the treated area in a fixed position. Each year there are about 1.3 million spinal surgeries performed in US alone. The miss-insertion rates in the lumbar spine region have been documented to be from 5% - 41%[1]. This paper provides a perspective on the development of vision assist system for an automated robot for fixation of pedicle-screw. Pedicle screw fixation devices are considered as class III medical devices. The technique of pedicle screw insertion in the spine has gone through significant development over the last two decades. Aim of this paper is to decrease the error rates by implementing an image-processing method which intends to eliminate the use of intra-operative fluoroscopy, MRI and CT.

Comparing Postoperative Leg Length Discrepancy and Femoral Offset Using Two Different Surgical Approaches for Hemiarthroplasty of the Hip.

INTRODUCTIONThe direct anterior approach (DAA) and anterolateral approach (ALA) may be used for hip hemiarthroplasty (HHA) as a treatment for femoral neck fractures. The DAA often utilizes intraoperative fluoroscopy to determine leg length and offset, while the ALA traditionally utilizes an intraoperative clinical exam to determine offset and leg length. This study will evaluate two techniques: the “grid fluoroscopy [GF] technique” and the “intraoperative exam [IE] technique,” each performed by one of two separate surgeons, and compare each technique’s accuracy to restore leg length and femoral offset in a patient population that underwent HHA.METHODSTwo investigators retrospectively reviewed charts of 208 randomly selected patients who had an HHA from either a DAA or ALA performed by two different surgeons for the treatment of femoral neck fractures. Postoperative AP pelvis radiographs were measured to determine offset and leg length compared with the non-operative extremity. Non-normal continuous variables were provided by median and interquartile range. Data were analyzed with the Mann-Whitney U test and Student’s t-test.RESULTSAfter inclusion and exclusion criteria, data were reviewed on 173 hemiarthroplasties. The mean age was 80.3 years (± 11.2 years). Of the surgical patients, 65.9% were female, and 70.9% identified their ethnicity as white. The DAA was used in 93 patients and ALA in 80 patients. Analysis comparing the two techniques demonstrated no statistically significant differences in median leg length between GF technique (1.02 IQR -0.1, 2.0 mm) and IE technique (1.25 IQR -2.4, 1.3 mm,) (p=0.67). There was also no statistically significant difference in offset between GF technique (1.3 IQR 0.2, 2.1 mm) and IE technique (0.6 IQR -2.7 mm, 3.2 mm) (p=0.13). However, a difference was found in mean length of surgery that was statistically significant. We found that the mean length of surgery for the IE technique was 74.8 ± 24.7 minutes versus the GF technique, which was 95.1 ± 23.0 minutes, (p<0.0001).DISCUSSIONThere was no significant difference between leg length and offset with the use of intraoperative fluoroscopy with DAA compared to no intraoperative imaging with ALA. Our study suggests that DAA and ALA are equally effective approaches for re-establishing symmetric leg length and offset in HHA for femoral neck fractures. In this study, the ALA had a shorter surgical time compared to DAA, potentially due to the utilization of intraoperative fluoroscopy for this particular technique during the DAA.

Assessment of clinical and radiographic outcomes following retrograde versus antegrade nailing of infraisthmic femoral shaft fractures without the use of intraoperative fluoroscopy in Tanzania

Objectives:To compare clinical and radiographic outcomes following antegrade versus retrograde intramedullary nailing of infraisthmic femoral shaft fractures.Design:Secondary analysis of prospective cohort study.Setting:Tertiary hospital in Tanzania.Participants:Adult patients with infraisthmic diaphyseal femur fractures.Intervention:Antegrade or retrograde SIGN intramedullary nail.Outcomes:Health-related quality of life (HRQOL), radiographic healing, knee range of motion, pain, and alignment (defined as less than or equal to 5 degrees of angular deformity in both coronal and sagittal planes) assessed at 6, 12, 24, and 52 weeks postoperatively.Results:Of 160 included patients, 141 (88.1%) had 1-year follow-up and were included in analyses: 42 (29.8%) antegrade, 99 (70.2%) retrograde. Antegrade-nailed patients had more loss of coronal alignment (P = .026), but less knee pain at 6 months (P = .017) and increased knee flexion at 6 weeks (P = .021). There were no significant differences in reoperations, HRQOL, hip pain, knee extension, radiographic healing, or sagittal alignment.Conclusions:Antegrade nailing of infraisthmic femur fractures had higher incidence of alignment loss, but no detectable differences in HRQOL, pain, radiographic healing, or reoperation. Retrograde nailing was associated with increased knee pain and decreased knee range of motion at early time points, but this dissipated by 1 year. To our knowledge, this is the first study to prospectively compare outcomes over 1 year in patients treated with antegrade versus retrograde SIGN intramedullary nailing of infraisthmic femur fractures.Level of Evidence: III

Level of Supervision and Radiation Exposure of Senior Orthopedic Residents During Surgical Treatment of Proximal Femur Fracture.

The sustained use of intraoperative fluoroscopy has led to increased use of minimally invasive surgical techniques, enhanced surgeon proficiency, improved anatomic corrections, reduced patient morbidity, earlier functional recovery, and decreased length of hospital stay. As a result, orthopedic attending surgeons and residents are exposed to more radiation, increasing the risk of cancer and radiation-induced cataracts compared with the general population and those who work in other surgical specialties. The magnitude of radiation exposure depends on the susceptibility of the tissues affected, medical specialty, the position of the C-arm, distance from the radiation beam, level of difficulty of the surgical procedure, surgeon experience, level of resident training, and level of supervision by the attending surgeon. However, little information is available on the effect of supervision level on radiation exposure for orthopedic senior residents. The goal of this study was to investigate whether level of supervision by the attending surgeon affects the radiation exposure of orthopedic senior residents during surgical treatment of proximal femur fracture with cephalomedullary nail fixation. This retrospective cohort study was performed from January 2019 to March 2019. No significant relationship between supervision level and radiation exposure of senior residents was observed. Supervision level does not significantly affect radiation exposure for senior residents; therefore, the implementation of standardized training in radiation safety may be a more essential measure to decrease radiation exposure. [Orthopedics. 2021;44(3):e402-e406.].

Double-trajectory lumbar screw placement guided by a set of 3D-printed surgical guide templates: a cadaver study

BackgroundTo improve the strength of posterior spine fixation in patients with osteoporosis, some scholars have proposed a method of simultaneously inserting traditional pedicle screws and cortical bone trajectory screws into the pedicle. However, due to the difficulty of the operation and few clinical applications, the safety and accuracy of this method are still unclear. The purpose of this study was to investigate the safety and accuracy of double-trajectory lumbar screw placement guided by surgical guide templates.MethodsSix wet lumbar specimens were selected for computed tomography (CT) scanning, a three-dimensional (3D) model of the lumbar spine was established using computer software, and surgical guide templates for double-trajectory [traditional pedicle trajectory (TPT) and cortical bone trajectory (CBT)] lumbar screw placement at various segments of the lumbar spine were designed and printed using a 3D printer. Screw placement was guided only by the surgical guide template, with no fluoroscopy. Postoperative CT examination was performed to determine whether the screw penetrated the screw path and the location and depth of penetration of the cortex. The preoperative and postoperative sagittal and axial angles of CBT screws or TPT screws were also measured and compared.ResultsFour screws were placed in each vertebral body of six lumbar specimens for a total of 120 screws. Screw grades: 99 screws as grade 0, 15 as grade 1, six as grade 2, and zero as grade 3. Thus, grade 0 accounted for 82.5% of the screws. No significant differences in the preoperative and postoperative angles of the screws were found (P > 0.05).Conclusions3D-printed surgical guide templates for double-trajectory screw placement can reduce the difficulty of surgery and the use of intraoperative fluoroscopy. Using such templates is a safe, feasible, and accurate screw placement method.

Managing Hip-Spine Concepts in the Direct Anterior Approach With Use of Fluoroscopy

BackgroundThe spinopelvic relationship in regard to total hip arthroplasty has become a topic of increasing interest in recent years. Hip arthritis and a stiff lumbar spine create a situation where the spinopelvic junction has decreased mobility, which in turn increases the risk of instability after total hip arthroplasty as the femoral acetabular joint must undergo increased motion. Regardless of the approach, surgeons should be aware of the risk of instability in patients with a stiff spinopelvic junction and the necessary modifications to component positioning to avoid postoperative instability. As many direct anterior approach surgeons use fluoroscopy for intraoperative navigation, anterior approach surgeons must also understand how to best use this technology to improve component positioning. MethodsIn this article, we address the basic concepts surrounding spinopelvic stiffness, the intraoperative component adjustments necessary for optimizing stability, and how to appropriately use fluoroscopy for navigation in the direct anterior approach. ConclusionsAppropriate use of intraoperative fluoroscopy includes understanding the impact of parallax and distortion, properly recreating the patient’s standing functional pelvic plane intraoperatively and adjusting the cup’s target position based on a preoperative understanding of the patient’s spinopelvic motion.

Novel Use of Intraoperative Fluoroscopy in an Era of ICG for Complex Laparoscopic Cholecystectomy

Background Laparoscopic cholecystectomy (LC) is increasingly being used as a first-line treatment for acute cholecystitis. Bile duct injury (BDI) remains the most feared complication of the minimally invasive approach specially in cases with an inflamed calots triangle. While use of indocyanine dye (ICG) to delineate biliary anatomy serves to reduce BDI, the high cost of the technology prohibits its use in the developing world. We propose a novel use of common bile duct (CBD) stenting preoperatively in cases of cholecystitis secondary to choledocholithiasis as a means of identification and safeguarding the CBD. Methods A retrospective review was conducted on 22 patients of Grade 2 or Grade 3 cholecystitis who underwent an early LC at our institution. All patients were stented preoperatively and the stent was used for a much-needed tactile feedback during dissection. A c-arm with intraoperative fluoroscopy was used to identify the CBD prior to clipping of the cystic duct. Results The gall bladder was gangrenous in all the cases while two cases had evidence of end organ damage. This innovative use of CBD stenting allowed us to correctly delineate biliary anatomy in all of the cases and we report no instances of BDI despite a severely inflamed local environment. Conclusion This technique can become a standard of care in all teaching institutions in developing countries further enhancing the safety of cholecystectomy in gangrenous cholecystitis with a distorted biliary anatomy.

Utility of Intraoperative Fluoroscopic Positioning of Total Hip Arthroplasty Components Using a Posterior and Direct Anterior Approach.

Positioning of implant components for total hip arthroplasty (THA) is important for polyethylene liner wear, prosthesis joint stability, and range of motion. The introduction of fluoroscopy for the direct anterior approach has been shown to improve physician accuracy for component positioning. Few studies compare the use of intraoperative fluoroscopy for THA component positioning in posterior THA. The purpose of this project is to retrospectively evaluate the effect of intraoperative fluoroscopy on component positioning for THA using posterior and direct anterior approach (DAA). A retrospective review of postoperative weight-bearing X-ray films of THAs was performed over a 2-year period where a single fellowship-trained total joint surgeon introduced direct anterior approach into his practice while expanding the intraoperative use of fluoroscopy for all THA procedures, regardless of approach. Component position was evaluated through radiographic measurement of acetabular cup inclination (goal of 40 degrees), limb length discrepancy (goal of 0 mm), and femoral component offset difference (goal of 0 mm). Radiographic analysis was performed by two independent providers. Statistical analysis was performed using Student's t-tests. A total of 107 patients with an average age of 62 years were identified during the 2-year period surrounding the THA practice change, adding fluoroscopy to posterior and DAA THA. Three cohorts were identified: cohort A: 44 patients who underwent posterior THAs without the use of intraoperative fluoroscopy, cohort B: 35 patients who underwent direct anterior approach THAs with the use of intraoperative fluoroscopy, and cohort C: 18 patients who underwent posterior THAs with the use of intraoperative fluoroscopy. The use of intraoperative fluoroscopy for the posterior approach versus unguided posterior approach increased accuracy of both cup inclination (44 degrees vs 50 degrees, P < .05) and femoral offset (4 mm vs 7 mm, P < .05). A comparison of DAA with fluoroscopy versus posterior approach without fluoroscopy showed improvement in cup inclination (48 degrees vs 50 degrees, P < .05). Fluoroscopy with posterior approach versus fluoroscopy with DAA was found to have improved cup inclination (44 degrees vs 48 degrees, P < .05). Intraoperative use of fluoroscopy can improve component positioning for posterior THA.

Intra-operative referencing technique is non-inferior to use of fluoroscopy for acetabular component positioning in anterior hip arthroplasty

BackgroundIntra-operative fluoroscopy has been shown to improve the accuracy of acetabular component positioning when compared to no fluoroscopy in direct anterior approach (DAA) total hip arthroplasty (THA). Due to logistical reasons, our senior author has been performing DAA THA at one institution without the use of fluoroscopy and has created an intraoperative referencing technique to aid in acetabular component positioning. The purpose of this study is to evaluate the accuracy of acetabular component positioning using fluoroscopy when compared to an intra-operative referencing technique without fluoroscopy. MethodsA total of 214 consecutive primary DAA THA were performed by one surgeon at two institutions and were retrospectively reviewed over a 3-year period. Intra-operative fluoroscopy was used with all patients at Institution A (N = 154). At institution B (N = 60), no fluoroscopy was used, and an intra-operative referencing technique was employed to assist in placement of the acetabular component. ResultsIn the fluoroscopy group, 91% of components met our abduction target, 90% met our anteversion target, and 82.5% simultaneously met both targets. In the non-fluoroscopy group, 98% of components met our abduction target, 92% met our anteversion target, and 90% simultaneously met both targets. There was no difference between groups for placement of the component within both targets simultaneously (p = .171). ConclusionUse of our intra-operative referencing technique is non-inferior in placing acetabular components within a pre-defined safe zone when compared to use of intraoperative fluoroscopy. The intra-operative reference technique can be a helpful adjunct for ensuring accurate acetabular component positioning while simultaneously reducing cost and limiting radiation exposure.

140. Complications and revision rates in minimally invasive Mazor robotic-guided vs fluoroscopic-guided spinal fusions: the MIS ReFRESH prospective comparative study

BACKGROUND CONTEXT As robotic-guidance and minimally invasive approaches become more prevalent in spine surgery, there is a growing interest in high-level scientific evidence of their clinical value. MIS ReFRESH is the first prospective, multicenter study designed to compare robotic-guidance and fluoroscopic techniques for differences in surgical complications, revision surgery rates and exposure to intraoperative radiation. The MIS ReFRESH study assessed adults undergoing minimally invasive (MIS) lumbar fusions of 1-3 levels. PURPOSE To prospectively assess the impact of Mazor robotic-guidance compared to fluoro-guidance on the rates of surgical complications, revision surgery and intraoperative radiation exposure in MIS short lumbar fusions. STUDY DESIGN/SETTING Prospective, multicenter, controlled, partially randomized study. PATIENT SAMPLE Adult patients with degenerative lumbar conditions undergoing minimally invasive fusion of 1-3 levels. OUTCOME MEASURES Comparison of incidence of surgical complications, revision surgeries and intraoperative fluoroscopy time. Analysis of variables through Cox logistic regression model and a Kaplan Meyer Survival Curve of surgical complications. METHODS Data were prospectively collected from adult patients indicated for lumbar fusion surgery, including demographics, comorbidities, surgical complications, revision surgeries and use of intraoperative fluoroscopy (in seconds). A single site randomized patients between arms, while other sites enrolled exclusively to one arm. Primary endpoints were analyzed at 1-year follow-up. RESULTS A total of 9 sites enrolled 485 patients: 374 in the robot-guided arm (RG), and 111 in the fluoro-guided arm (FG). One site randomized patients, 16 to RG and 11 to FG. 93.2% of patients had >1 year follow-up and were included in the analysis of primary endpoints. There were no differences between the groups with regards to gender, Charlson Comorbidity Index (CCI), Diabetes, Cancer or HIV status. RG patients were significantly heavier, younger and included more smokers. Mean age of RG patients was 59.0 years vs 62.5 for FG (p=0.009) and BMI was 31.2 vs 28.1, respectively (p CONCLUSIONS In a prospective, multicenter, comparative study of MIS lumbar fusions, surgeries performed with Mazor robotic guidance were found to have a 5.2 times lower risk of developing a surgical complication and 8.8 times lower risk for revision surgery compared to fluoro-guidance during the first year of follow-up. Normalized surgical times/instrumentation were similar between the two groups and RG reduced fluoro time per screw by 80%, or approximately a minute per case. FDA DEVICE/DRUG STATUS Mazor Renaissance Robotics (Approved for this indication).