Intraoperative 3D Fluoroscopy Research Articles

Intraoperative 3D Fluoroscopy During Open Reduction for DDH: An Effective Alternative to Postoperative CT/MRI.

Computed tomography CT or magnetic resonance imaging (MRI) has been the most used imaging modality to assess hip reduction in developmental dysplasia of the hip (DDH) after open reduction (OR). In 2015, intraoperative 3D fluoroscopy (3D) was introduced at our center as an alternative to CT/MRI. 3D offers the advantage that if hip reduction is insufficient, it can be addressed at the time of surgery. The purpose of this study was to assess the efficacy of 3D in comparison to CT/MRI. This was a single-centre, retrospective comparative study of two consecutive cohorts: those with OR and 3D between 2015 and 2017 and those with OR and CT/MRI between 2012 and 2014. Time to imaging, re-imaging, length of stay (LOS), re-operation, and redislocation or subluxation after cast removal were evaluated. Forty-two patients (46 hips) had 3D, and 30 patients (32 hips) had CT/MRI. Significant differences were found between groups in time to imaging, cast changes, and LOS. All 3D was intraoperative (46 hips), and only 69% (22 hips) of CT/MRI was on the day of surgery (P<0.01). In the 3D group, 1 hip (2%) had a cast change under the same anesthetic, and 4 hips (13%) from CT/MRI had cast changes in subsequent surgery (P=0.03). The mean LOS in days for 3D was 1.72 and 2.20 for CT/MRI (P=0.03). There were no statistically significant differences between groups in further imaging and subluxations or re-dislocations at cast removal. Two hips (4%) in the 3D group had MRI, but with no further intervention (P=0.51), and at cast removal, there were 3 subluxations in each group (P=0.69) and 1 redislocation in the 3D group (P=1.00). Intraoperative 3D improved time to imaging, allowed for cast changes at surgery and had a shorter LOS. Moreover, there were no significant differences found in adverse outcomes between those who underwent 3D versus CT/MRI. 3D should thus be considered an effective alternative to CT/MRI for assessing hip reduction during OR for DDH. Diagnostic Study, level II.

Early Pneumatocele Identification Post-Robotic Assisted Bronchoscopy Cryobiopsy: A Case Series Experience

Introduction: The use of cryobiopsy in conjunction with robotic assisted bronchoscopy is on the rise due to the safety and increased diagnostic yield of cryobiopsy. The incorporation of 3D fluoroscopy in the procedure improves the workflow and helps confirm the accuracy of sampling of peripheral pulmonary nodules. Methods: We describe an observational series of 12 patients comprising 14 nodules where cryobiopsy was performed during shape-sensing robot-assisted bronchoscopy cryobiopsy under general anesthesia. 3D fluoroscopy was used to confirm accurate placement of the cryoprobe. All these patients underwent a second spin with the 3D fluoroscopy either to sample a second lesion intraoperatively or to investigate suspected pneumothorax. Results: The development of a pneumatocele was noted after cryobiopsy in each of the cases. The majority of these were in the upper lobe with the median size of a sampled nodule being 14 mm. The majority of patients were asymptomatic with 1 patient developing mild hemoptysis and 4 patients developing chest tightness or dyspnea. None of the patients required an intervention for the pneumatocele. Conclusion: The development of pneumatoceles appears to be a fairly frequent and benign occurrence following cryobiopsy, likely due to increased tissue destruction. The increased use of intraoperative 3D fluoroscopy is likely to highlight changes to the pulmonary parenchyma that were previously not known. The occurrence of pneumatoceles does not appear to adversely impact the safety or tolerability profile of cryobiopsy.

Improved Side-Effect Stimulation Thresholds and Postoperative Transient Confusion With Asleep, Image-Guided Deep Brain Stimulation.

Asleep, image-guided deep brain stimulation (DBS) is a modern alternative to awake, microelectrode recording (MER) guidance. Studies demonstrate comparable efficacy and complications between techniques, although some report lower stimulation thresholds for side effects with image guidance. In addition, few studies directly compare the risk of postoperative transient confusion (pTC) across techniques. The purpose of this study was to compare clinical efficacy, stimulation thresholds for side effects, and rates of pTC with MER-guided DBS vs intraoperative 3D-fluoroscopy (i3D-F) guidance in Parkinson's disease and essential tremor. Consecutive patients from 2006 to 2021 were identified from the departmental database and grouped as having either MER-guided DBS or i3D-F-guided DBS insertion. Directional leads were used once commercially available. Changes in Unified Parkinson's Disease Rating Scale (UPDRS)-III scores, levodopa equivalent daily dose, Fahn-Tolosa-Marin scores, and stimulation thresholds were assessed, as were rates of complications including pTC. MER guidance was used to implant 487 electrodes (18 globus pallidus interna, GPi; 171 subthalamic nucleus; 76 ventrointermediate thalamus, VIM) in 265 patients. i3D-F guidance was used in 167 electrodes (19 GPi; 25 subthalamic nucleus; 41 VIM) in 85 patients. There were no significant differences in Unified Parkinson's Disease Rating III Scale, levodopa equivalent daily dose, or Fahn-Tolosa-Marin between groups. Stimulation thresholds for side effects were higher with i3D-F guidance in the subthalamic nucleus (MER, 2.80 mA ± 0.98; i3D-F, 3.46 mA ± 0.92; P = .002) and VIM (MER, 2.81 mA ± 1.00; i3D-F, 3.19 mA ± 1.03; P = .0018). Less pTC with i3D-F guidance (MER, 7.5%; i3D-F, 1.2%; P = .034) was also found. Although clinical efficacy between MER-guided and i3D-F-guided DBS was comparable, thresholds for stimulation side effects were higher with i3D-F guidance and the rate of pTC was lower. This suggests that image-guided DBS may affect long-term side effects and pose a decreased risk of pTC.

Extended curettage for tumour-induced osteomalacia in the bone.

extended curettage is generally used to treat infiltrative bone tumours. However, the extent of the curettage performed in previous studies remains unclear. This study aimed to investigate the efficacy of extended curettage for bone tumour-induced osteomalacia. we included 12 patients with tumour-induced osteomalacia who underwent extended curettage at our hospital between 2000 and 2022. Extended curettage was applied in cases where tumour resection could cause functional impairment or necessitate complex reconstruction. We investigated patients' clinical and oncological outcomes. patients had a mean age of 55 (24-81) years, and the median follow-up duration after surgery was 3.9 (1.0-14.0) years. The causative tumours were located in the pelvis and lumbar spine. Imaging revealed the tumours to be of the sclerotic, intertrabecular, lytic and mixed types. Intraoperative 3D fluoroscopy was used in 10 patients. Extended curettage with high-speed burring and adjuvant therapy with cauterization using an electric scalpel and ethanol resulted in a remission rate of 83%; no recurrence or metastasis was observed in cases of early postoperative biochemical remission. In cases where the causative tumour was at the lumbar spine and ischium close to the acetabulum, no postoperative biochemical remission was observed, and conservative treatment was continued. Except for one patient with a tumour in the lumbar spine, all patients could walk without a cane. extended curettage for bone tumour-induced osteomalacia is oncologically and functionally favourable, especially in cases where resection of the causative tumour could cause functional impairment or necessitate complex reconstruction.

Use of 3D Fluoroscopy to Assist in the Reduction and Fixation of Pelvic and Acetabular Fractures: A Safety and Quality Case Series.

Multidimensional fluoroscopy has been increasingly used in orthopaedic trauma to improve the intraoperative assessment of articular reductions and implant placement. Owing to the complex osteology of the pelvis, cross-sectional imaging is imperative for accurate evaluation of pelvic ring and acetabular injuries both preoperatively and intraoperatively. The continued development of fluoroscopic technology over the past decade has resulted in improved ease of intraoperative multidimensional fluoroscopy use in pelvic and acetabular surgery. This has provided orthopaedic trauma surgeons with a valuable tool to better evaluate reduction and fixation at different stages during operative treatment of these injuries. Specifically, intraoperative 3D fluoroscopy during treatment of acetabulum and pelvis injuries assists with guiding intraoperative decisions, assessing reductions, ensuring implant safety, and confirming appropriate fixation. We outline the useful aspects of this technology during pelvic and acetabular surgery and report its utility with a consecutive case series at a single institution. The added benefits of this technology have improved the ability to effectively manage patients with pelvis and acetabulum injuries.

Intraoperative 3D-Fluoroscopy Increases Accuracy of Syndesmotic Reduction in Ankle Fractures with Syndesmotic Instability

Abstract Background Direct visual control and 2D-fluoroscopy is widely used to achieve an anatomic syndesmotic reduction in ankle fractures with syndesmotic instability. However, significant malreduction rates are reported. Aims It was the aim of this study to evaluate the accuracy of conventional syndesmotic reduction and to assess the impact of intraoperative 3D-imaging to improve the quality of syndesmotic reduction. Methods Single institution consecutive case series (02/2021–12/2022) including all patients undergoing operative treatment for ankle fractures with syndesmotic instability. Syndesmotic reduction was performed following open reduction and internal fixation of the malleolar fractures. Provisional tibiofibular alignment was obtained under visual control and 2D-fluoroscopy. With the ankle held in a neutral position, temporary fibulotibial transfixation was performed with 2 K-wires. 3D-imaging was obtained (Cios Spin, Siemens Healthineers, Forchheim-Germany). Non-anatomical positions of the fibula were devided into anterior, posterior, or rotational malreductions. If reduction was not satisfactory, the reduction was improved and 3D-imaging repeated. Once adequate reduction was obtained, definitive syndesmotic fixation was performed and the K-wires were removed. Results A total of 50 patients (mean age 44±16 years, m/f 27/23) were operated for ankle fractures with syndesmotic instability. Intraoperative 3D-imaging confirmed anatomic syndesmotic reduction in 31 patients (62%). In 15 patients (30%) reduction was repeated once, in 4 patients (8%) two additional reduction manoeuvers were necessary to obtain an anatomic result. Thus, a total of 23 malreductions were recorded in a total of 73 reduction manoeuvers (32%). Of these, we observed 16 anterior (70%), 2 posterior (9%) and 5 rotational malreductions (22%). Conclusions Syndesmotic reduction under visual control and 2D-fluoroscopy proved to be unreliable with a syndesmotic malreduction in almost one-third of all reduction manoeuvers. With the help of intraoperative 3D-imaging incorrect tibiofibular alignment before definite fixation was identified, reduction corrected and thereby the rate of malreductions reduced.

P119. Are biplanar projection radiographs sufficient to confirm intraoperative pedicle screw placement?

<h3>BACKGROUND CONTEXT</h3> Two-dimensional BPR (AP and lateral fluoroscopy or x-ray) has been the gold standard in spine fusion surgery for many years, however, 3D intraoperative imaging systems are now available. When utilizing BPR for pedicle screw confirmation, significant misplacement rates have been reported in the lumbar and thoracic spine. <h3>PURPOSE</h3> Biplanar projection radiographs (BPR) for confirmation of intraoperative pedicle screw placement are inferior to three-dimensional fluoroscopic (3D) imaging. <h3>STUDY DESIGN/SETTING</h3> Retrospective review of prospectively collected data. <h3>PATIENT SAMPLE</h3> A total of 100 patients underwent degenerative spinal surgery by one spine surgeon. <h3>OUTCOME MEASURES</h3> Screw placement was compared between postoperative CT, intraoperative x-rays( BPR) and intraoperative 3D fluoroscopic imaging. <h3>METHODS</h3> One hundred patients underwent degenerative spinal surgery by one spine surgeon and screw placement was compared from preoperative CT images to intraoperative 3D fluoroscopy. The M-line and Gertzbein-Robbins system (GRS) was used to confirm false positives or negatives in BPR. M-line was defined as a line connecting the upper and lower spinous processes through the fixed vertebrae within BPR. GRS measures pedicle screw accuracy and categorizes positions into 4 groups based on a clinical positioning grading used in 3D imaging. <h3>RESULTS</h3> A total of 604 instrumented pedicles in 100 patients were planned robotically, 497 (82.2%) were placed robotically. Each patient received a postoperative CT, intraoperative X-rays (BPR), and intraoperative 3D fluoroscopic imaging. M-Lines were measured for each patient vias intraoperative X-ray postoperatively. Patient postoperative CTs were compared to intraoperative 3D fluoroscopy by the GRS method. Postoperative CTs were then compared to M-line findings in BPR, to confirm whether false positives or negatives were detected. Based on BPR imaging, 5 (5%) patients exhibited 5 (0.8%) screws which were all robotically placed screws crossing the M-line in BPR. However, when compared to their postoperative CT imaging, breach was not detected and was classified as fully within the pedicle (category A of GRS). A BPR in a separate patient (1%) did exhibit one screw (0.2%) with a false negative BPR compared to 3D imaging. This could be possibly due to anatomical rotation in BPR. <h3>CONCLUSIONS</h3> A clinically significant number of patients had false-negative and false-positive screw confirmation on BPR. In 5% of patients and 0.8% of screws, a false-negative breaching within robotically placed screws was seen. Furthermore, 1% of patients and 0.2% of screws showed a false negative of pedicle screw mal-positioning. BPR may yield a false sense of security for misplaced screws and conversely may raise concern over screws that are in a satisfactory position. These findings may make 3D imaging a more desirable post-instrumentation gold standard. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Poster 229: Improved Epiphyseal Socket Placement with Intraoperative 3D Fluoroscopy: Consecutive Series of Pediatric All-epiphyseal Anterior Cruciate Ligament Reconstruction.

Objectives:All-epiphyseal anterior cruciate ligament reconstruction (ACLR) is a safe procedure for skeletally immature patients with ACL tears because the sockets are contained within the epiphysis and do not cross the growth plate. However, due to the undulation of the distal femoral physis, accidental disturbance of the growth plate during tunnel placement is possible. It is imperative to obtain intraoperative imaging to view the trajectory of the guide wire prior to reaming the socket. The purpose of this study was to investigate the effect of the use of 3D intraoperative fluoroscopy on socket placement in patients undergoing all-epiphyseal ACLR. We hypothesized that 3D imaging would allow for better intraoperative visualization of the growth plate and a smaller incidence of growth plate violation.Methods:Patients under the age of 18 who underwent a primary ACLR between 2011 and 2018 by the senior authors were retrospectively reviewed. Patients that underwent an all-epiphyseal ACLR with an available postoperative MRI were included. Demographic data, surgical details and type of intraoperative fluoroscopy were collected. The minimal distances between the femoral socket and distal femoral physis (DFP) and tibial socket and proximal tibial physis (PTP) were recorded. Sockets that touched the physis or extended into the metaphysis were recorded as zero. Patients were split into two groups; a 2D imaging group that received intraoperative anterior to posterior and lateral fluoroscopic radiographs and a 3D fluoroscopy imaging group. Interrater reliability of radiographic measurements was evaluated using intraclass correlation coefficient (ICC). Statistical analysis was performed using a student’s t-test to determine differences between groups.Results:72 patients fit the inclusion criteria and were retrospectively reviewed. 54 patients had 2D imaging and 18 patients had 3D imaging. The mean age of the cohort at time of surgery was 12.3 ± 1.5 years, 79% of patients were male, and 54% tore their left ACL. The mean time from surgery to postoperative MRI was 2.0 ± 1.1 years. The ICC was 0.92 (95% CI 0.35-0.98), indicating almost perfect interrater reliability. The mean difference in distance between the tibial socket and the PTP was significantly less in the 2D imaging group than the 3D imaging group (1.2 ± 1.7mm vs 2.5 ± 2.2mm, p=0.03). (Table 1). The femoral socket touched or extended beyond the DFP significantly less in the 2D group than in the 3D group (13% vs 43%, p<0.000).Conclusions:There was a significantly decreased incidence of DFP violation with use of 3D intraoperative imaging for all-epiphyseal ACLR socket placement. Surgeons should consider utilizing 3D imaging to potentially decrease the rate of growth disturbance due to physis violation in these patients.

Improved epiphyseal socket placement with intraoperative 3D fluoroscopy: a consecutive series of pediatric all-epiphyseal anterior cruciate ligament reconstruction.

Disturbance of the growth plate during all-epiphyseal anterior cruciate ligament reconstruction (ACLR) socket placement is possible due to the undulation of the distal femoral physis and proximal tibial physis. Therefore, it is important to obtain intraoperative imaging of the guide wire prior to reaming the socket. The purpose of this study was to investigate the effect of the use of 3D intraoperative fluoroscopy on socket placement in patients undergoing all-epiphyseal ACLR. It was hypothesized that 3D imaging would allow for more accurate intraoperative visualization of the growth plate and hence a lower incidence of growth plate violation compared to 2D imaging. Patients under the age of 18 who underwent a primary all-epiphyseal ACL reconstruction by the senior authors and had an available postoperative MRI were retrospectively reviewed. Demographic data, surgical details, and the distances between the femoral socket and distal femoral physis (DFP) and tibial socket and proximal tibial physis (PTP) were recorded. Patients were split into two groups based on type of intraoperative fluoroscopy used: a 2D group and a 3D group. Interrater reliability of radiographic measurements was evaluated using intraclass correlation coefficient (ICC). Seventy-two patients fit the inclusion criteria and were retrospectively reviewed. 54 patients had 2D imaging and 18 patients had 3D imaging. The mean age at time of surgery was 12.3 ± 1.5years, 79% of patients were male, and 54% tore their left ACL. The mean time from surgery to postoperative MRI was 2.0 ± 1.1years. The ICC was 0.92 (95% CI 0.35-0.98), indicating almost perfect interrater reliability. The mean difference in distance between the tibial socket and the PTP was significantly less in the 2D imaging group than the 3D imaging group (1.2 ± 1.7mm vs 2.5 ± 2.2mm, p = 0.03). The femoral and tibial sockets touched or extended beyond the DFP or PTP, respectively, significantly less in the 3D group than in the 2D group (11% vs 43%, p < 0.000, 17% vs 65%, p < 0.000). There was a significantly increased distance from the PTP and decreased incidence of DFP violation with use of 3D intraoperative imaging for all-epiphyseal ACLR socket placement. Surgeons should consider utilizing 3D imaging prior to creating femoral and tibial sockets to potentially decrease the risk of physis violation in these patients. III.

Atlantoaxial posterior screw fixation using intra-operative spinal navigation with three-dimensional isocentric C-arm fluoroscopy.

Intra-operative image acquisition coupled with navigation aims to increase screw placement accuracy, and it is particularly helpful in complex spinal procedures. The aim of this study is to analyze the accuracy and reliability of posterior atlanto-axial fixation using spinal navigation combined with intra-operative 3D isocentric C-arm. We retrospectively reviewed all patients presenting with C1-C2 instability and treated by posterior atlanto-axial fixation in our center between December 2016 and September 2018. Screw positioning was guided by intra-operative navigation, registered with surface matching procedure on a previously obtained CT scan and controlled by intra-operative 3D isocentric C-arm. Age, sex, pre- and post-operative neurological status, duration of surgery, presence/absence of vertebral artery injury, and screw placement were retrospectively collected from patients' records. All patients underwent clinical and radiological follow-up at threemonths after surgery. Radiological assessment of screw positioning was performed by an independent radiologist using the Gertzbein and Robbins grading. N = 11 (7F, 4M) consecutive patients were included, with a mean age of 72years (range from 51 to 85). N = 44 navigated screws were inserted and controlled with intra-operative 3D fluoroscopy at the end of the procedure. An acceptable screw positioning (Gertzbein-Robbins grade A and B) was obtained in all cases (100%). No vertebral artery injury was observed. Mean operating time was 123minutes. At threemonths, no screw loosening or displacement was observed. In our experience, spinal navigation coupled with intra-operative 3D fluoroscopy proved to be reliable and safe for C1-C2 screw placement.

Comparison of a ceiling-mounted 3D flat panel detector vs. conventional intraoperative 2D fluoroscopy in plate osteosynthesis of distal radius fractures with volar locking plate systems

ObjectivesTo compare intraoperative 3D fluoroscopy with a ceiling-mounted flat panel detector in plate osteosynthesis of distal radius fractures (AO/OTA 2R3C1.2) with volar locking plate systems to conventional 2D fluoroscopy for detection of insufficient fracture reduction, plate misplacement and protruding screws.MethodsUsing a common volar approach on 12 cadaver forearms, total intraarticular distal radius fractures were induced, manually reduced and internally fixated with a 2.4 distal radius locking compression plate. 2D (anterior-posterior and lateral) and 3D (rotational) fluoroscopic images were taken as well as computed tomographies. Fluoroscopic images, Cone Beam CT (CBCT), 360° rotating sequences (so called “Movies”) and CT scans were co-evaluated by a specialist orthopedic surgeon and a specialist radiologist regarding quality of fracture reduction, position of plate, position of the three distal locking screws and position of the three diaphyseal screws. In reference to gold standard CT, sensitivity and specifity were analyzed.Results“Movie” showed highest sensitivity for detection of insufficient fracture reduction (88%). Sensitivity for detection of incorrect position of plate was 100% for CBCT and 90% for “Movie.” For intraarticular position of screws, 2D fluoroscopy and CBCT showed highest sensitivity and specifity (100 and 91%, respectively). Regarding detection of only marginal intraarticular position of screws, sensitivity and specifity of 2D fluoroscopy reached 100% (CBCT: 100 and 83%). “Movie” showed highest sensitivity for detection of overlapping position of screws (100%). When it comes to specifity, CBCT achieved 100%. Regarding detection of only marginal overlapping position of screws, 2D fluoroscopy and “Movie” showed highest sensitivity (100%). CBCT achieved highest specifity (100%).ConclusionAs for assessment of quality of fracture reduction and detection of incorrect position of plate as well as overlapping position of the three diaphyseal screws CBCT and “Movie” are comparable to CT – especially when combined. Particularly sensitivity is high compared to standard 2D fluoroscopy.

Comparison of novel machine vision spinal image guidance system with existing 3D fluoroscopy-based navigation system: a randomized prospective study

BACKGROUND CONTEXTThe use of spinal image guidance systems (IGS) has increased patient safety, accuracy, operative efficiency, and reduced revision rates in pedicle screw placement procedures. Traditional intraoperative 3D fluoroscopy or CT imaging produces potentially harmful ionizing radiation and increases operative time to register the patient. An IGS, FLASH Navigation, uses machine vision through high resolution stereoscopic cameras and structured visible light to build a 3D topographical map of the patient's bony surface anatomy enabling navigation use without ionizing radiation. PURPOSEWe aimed to compare FLASH navigation system to a widely used 3D fluoroscopic navigation (3D) platform by comparing radiation exposure and pedicle screw accuracy. DESIGNA randomized prospective comparative cohort study of consecutive patients undergoing open posterior lumbar instrumented fusion. PATIENT SAMPLEAdults diagnosed with spinal pathology requiring surgical treatment and planning for open posterior lumbar fusion with pedicle screws implanted into 1-4 vertebral levels. OUTCOME MEASURESOutcome measures included mean intraoperative fluoroscopy time and dose, mean CT dose length product (DLP) for preoperative and day 2 CT, pedicle screw accuracy by CT, estimated blood loss and revision surgery rate. METHODSConsecutive patients were randomized 1:1 to FLASH or 3D and underwent posterior lumbar instrumented fusion. Radiation doses were recorded from pre- and postoperative CT and intraoperative 3D fluoroscopy. 2 independent blinded radiologists reviewed pedicle screw accuracy on CT. RESULTSA total of 429 (n=210 FLASH, n=219 3D) pedicle screws were placed in 90 patients (n=45 FLASH, n=45 3D) over the 18-month study period. Mean age and indication for surgery were similar between both groups, with a non-significantly higher ratio of males in the 3D group.Mean intraoperative fluoroscopy time and doses were significantly reduced in FLASH compared to 3D (4.51±3.71s vs 79.6±23.0s, p<.001 and 80.9±68.1cGycm2 vs 3704.1±3442.4 cGycm2, p<.001, respectively). This represented a relative reduction of 94.3% in the total intraoperative radiation time and a 97.8% reduction in the total intraoperative radiation dose. Mean preoperative CT DLP and mean day 2 postoperative CT DLP were significantly reduced in FLASH compared to 3D (662.0±440.4mGy-cm vs 1008.9±616.3 mGy-cm, p<.001 and 577.9±294.3 mGy-cm vs 980.7±441.6 mGy-cm, p<.001, respectively). This represented relative reductions of 34.4% and 41.0% in the preoperative CT dose and postoperative total DLP, respectively.The FLASH group required an average of 1.2 registrations in each case with an average of 2447 (±961.3) data points registered with a mean registration time of 106s (±52.1). A rapid re-registration mechanism was utilized in 22% (n=10/45) of cases and took 22.7s (±11.3). Re-registration was used in 7% (n=3/45) in the 3D group.Pedicle screw accuracy was high in FLASH (98.1%) and 3D (97.3%) groups with no pedicle breach >2mm in either group (p<.001). EBL was not statistically different between the groups (p=.38). No neurovascular injuries occurred, and no patients required return to theatre for screw repositioning. CONCLUSIONSFLASH and 3D IGS demonstrate high accuracy for pedicle screw placement. FLASH showed significant reduction in intraoperative radiation time and dose with lower but non-significant blood loss. FLASH showed significant reduction in preoperative and postoperative radiation, but this may be associated to the lower number of males/females preponderance in this group. FLASH provides similar accuracy to contemporary IGS without requiring 3D-fluoroscopy or radiolucent operating tables. Reducing registration time and specialized equipment may reduce costs.

Evaluation of K-wireless robotic and navigation assisted pedicle screw placement in adult degenerative spinal surgery: learning curve and technical notes.

K-wireless robotic pedicle screw instrumentation with navigation is a new technology with large potential. Barriers to adoption are added registration time with robotic-navigated system and reliable screw positioning. Understanding the learning curve and limitations is crucial for successful implementation. The purpose of this study was to describe a learning curve of k-wireless robotic assisted pedicle screw placement with navigation and compare to conventional techniques. A retrospective review of prospectively collected data of 65 consecutive adult patients underwent robotic-navigated posterior spinal fusion by a single spine surgeon. Registration, screw placement, and positioning times were recorded. All patients underwent intra-operative 3D fluoroscopy and screw trajectory was compared to pre-operative CT. A total of 364 instrumented pedicles were planned robotically, 311 (85.4%) were placed robotically; 17 screws (4.7%) converted to k-wire, 21 (5.8%) converted to freehand, and 15 (4.1%) planned freehand. Of the 311 robotically placed pedicle screws, three dimensional fluoroscopic imaging showed 291 (93.5%) to be GRS Grade A in the axial plane (fully contained within the pedicle) and 281 (90.4%) were GRS Grade A in the sagittal plane. All breached screw deviations from plan were identified on 3D fluoroscopy during surgery and repositioned and confirmed by additional 3d fluoroscopy scan. Reasons for conversion included morphology of starting point (n=18), soft tissue pressure (n=9), hypoplastic pedicles (n=6), obstructive reference pin placement (n=2), and robotic arm issues (n=1). Seventeen (5.5%) critical breaches (≥2-4 mm) were recorded in 11 patients, 9 (2.9%) critical breaches were due to soft tissue pressure causing skive. Two patients experienced 6 (1.9%) critical breaches from hypoplastic pedicles, and 3 (0.9%) unplanned lateral breaches were found in another patient. One patient (0.3%) experienced skive due to morphology and spinal instability from isthmic spondylolisthesis. Imaging showed 143 screws placed medially to plan (1.2±0.9 mm), 170 lateral (1.2±1.1 mm), 193 screws caudal (1.0±0.6 mm) and 117 cranial (0.6±0.5 mm). No adverse clinical sequelae occurred from implantation of any screw. The learning curve showed improvement in screw times for the first several cases. Understanding the learning curve and situations where the robotic technique may be suboptimal can help guide the surgeon safe and effectively for adoption, as well as further refine these technologies.

Effect of Intraoperative Multidimensional Fluoroscopy Versus Conventional Fluoroscopy on Syndesmotic Reduction.

Despite multiple techniques to improve syndesmotic reduction accuracy, syndesmotic malreduction in unstable ankle fractures remains prevalent. We performed a prospective, observational study to assess the ability of intraoperative multidimensional fluoroscopy to lead a surgeon to change the syndesmotic reduction obtained by conventional fluoroscopic techniques with the goal of achieving an accurate reduction. Thirty patients with unilateral malleolar ankle fractures and syndesmotic instability were enrolled. Following fixation of the malleollar fractures, the syndesmosis was provisionally reduced. Once the surgeon believed acceptable reduction was obtained by comparison with the contralateral, uninjured ankle mortise and lateral fluoroscopic images, provisional fixation was used to maintain reduction. Intraoperative, multidimensional fluoroscopy was used to generate cross-sectional images to assess the reduction. The surgeon then decided if a change in the reduction was needed, and fixation proceeded per surgeon preference. Postoperative bilateral computed tomography (CT) scans of the ankles were used to assess the reduction. The main outcome recorded was syndesmotic reduction change by the attending surgeon following 3-dimensional (3D) fluoroscopic imaging. The secondary outcome was syndesmotic reduction accuracy on postoperative CT scan. Fourteen of 30 patients had intraoperative reduction change following 3D fluoroscopic imaging. Three of 30 patients had residual malreduction compared with the contralateral ankle on bilateral postoperative CT scan. Intraoperative 3D fluoroscopy frequently led the surgeon to change the syndesmotic reduction obtained by conventional techniques and provided additional information not available with 2-dimensional fluoroscopy. A 10% syndesmotic malreduction rate was obtained with this technique. Diagnostic level II, prospective comparative study.

Accuracy of 2D Fluoroscopy with Preoperative CT Fused Neuronavigation in Thoracic and Lumbar Pedicle Screw Insertion

Aim: Pedicle screw fixation is an established technique in the lumbar and thoracic area. Fluoroscopy-guided screw placement and subsequently navigation have decreased the rate of misplaced screws, but no technique has wholly eliminated this risk. This paper aims to study the difference between the accuracy of the fluoroscopic guided screw placement to that of the 2D fluoroscopy- preop CT fused neuronavigation guided technique, a lesser-used navigation technique. &#x0D; Material and Methods: This retrospective study reflects our results using both techniques between March 2018 and March 2019 in both degenerative or traumatic spinal pathology for thoracic and lumbar regions. The accuracy of the screw placement was measured using Mirza grading system on postoperative CT images.&#x0D; Results: A total number of 56 patients underwent spinal instrumentation surgery. A total of 274 screws were placed with a mean number of 4.89 screws per patient; 199 screws were implanted using neuronavigation and 75 using the freehand-2D fluoroscopy-guided technique. The accuracy rate of pedicle screw placement in the freehand technique guided by 2D fluoroscopy was 88,00%. With the use of neuronavigation, the accuracy increased to 89,96%.&#x0D; Conclusion: Pedicle screw placement accuracy is higher when guided by CT-fluoro matching neuronavigation compared to freehand fluoroscopy-guided technique and can be used in departments where there is no intraoperative O-arm or 3D fluoroscopy available.

Minimal Invasive Percutaneous Kyphoplasty of C1 Lytic Lesion Using an Intraoperative 3D Imaging-Based Navigation System and Fluoroscopy

Background: Percutaneous kyphoplasty is a minimally-invasive techniques that aim to provide pain relief and bone stabilization by the injection of cement. Metastatic lesions of the atlas treated by this technique has been described in only few articles. Objective: We describe the use of kyphoplasty in a painful osteolytic lesion located in the left mass lateral of C1 with a postero lateral approach using 3D CT-scann intraoperative navigation system and fluoroscopy. Methods: A 58 year-old woman with metastastic breast neoplastic which admitted for treatment severe left-sided suboccipital exacerbated by head rotation and neck pain refractory to conventional medical treatment painkillers. CT scan and magnetic resonance imaging of the cervical spine revealed osteolytic destruction the left lateral mass of C1 . The patient underwent a percutaneous kyphoplasty managed using polymethylmetacrylate bone cement. Results: The patient reported post operative substantial pain relief . CT scan showed adequate filling of the osteolytic lesion without the obvious leakage of bone cement. the patient showed no clinical complications, while Clinical follow-up at 3 months revealed that this pain condition was improved and maintained. Conclusion: Minimally invasive percutaneous kyphoplasty using an intraoperative 3D navigation system and fluroscopy with postero lateral approach is a safe and effective alternative reducing post-operative morbidity and effective possibility in selected patients with C1 metastasis

Étude comparative de l’implantation des vis pédiculaires avec ou sans la navigation rachidienne dans la chirurgie du rachis dégénératif

Introduction The major limitation of computer-based 3D fluoroscopy is increased radiation exposure of patients and the operating-room (OR) team. Adjunction of spine navigation to intraoperative 3D fluoroscopy (io3DF) can likely overcome this shortcoming while increasing the pedicle screw accuracy rate. The purpose of the study is compare data from a cohort of patients undergoing lumbar percutaneous pedicle screw (PPS) placement utilizing io3DF alone or in combination with spine navigation. Material and methods We performed a cohort study of 168 patients who underwent PPS implantation between 2009 and 2016. Our primary endpoint was to compare the pedicle screw accuracy between the two groups. The secondary endpoints were to compare the exposure of patients and operating room (OR) staff to radiation, duration of surgery, and postoperative complications. Results A total of 438 screws were placed without navigation guidance (group 1) and 276 with spine navigation (group 2). The mean patient age in both groups was 58.6 years (SD: 14.1). The final pedicle accuracy rate was 97.9% in group 1 and 99.6% in group 2. The average radiation dose per patient was significantly larger in group 1 (571.9 mGym2) than in group 2 (365.6 mGym2) (P = 0.000088). Duration of the surgery and complication rate were not significantly different between the two groups (P > 0.05). Discussion The io3D fluoroscopy with spine navigation minimizes radiation doses on the patients and OR team, and increases pedicle screw accuracy with no permanent complications compared to io3DF alone. The setup is recommended, especially in cases with a complex degenerative spine.

Detection of primary screw perforation in locking plate osteosynthesis of proximal humerus fracture by intra-operative 3D fluoroscopy.

The purpose of this study was to identify the rate of primary screw perforations after osteosynthesis of proximal humerus fractures with intra-operative 3D fluoroscopy and to analyse the rate of secondary screw perforations as well as complications, outcome, and revision surgeries after a minimum of 12months. Thirty-three patients (20 female, 13 male, median age 67years, range 35-85years) with displaced proximal humerus fractures were included. After reduction and fixation, an intra-operative 3D fluoroscopy was performed to evaluate primary screw perforations (PS) and screws with "near perforation" (nPS). These screws were changed intra-operatively. Patients were followed-up for a minimum of 12months. Clinical and radiological parameters, such as secondary screw perforation, secondary loss of reduction, or functional outcome, were investigated. In six patients (18.2%), humeral head screws were changed due to primary PS (n=2) or nPS (n=4) after the intra-operative 3D fluoroscopy. Follow-up revealed an adapted constant score (%CMS) of 76.2% after a mean follow-up of 17.7months. Two secondary screw perforations were observed (6%). Loss of reduction was observed in eight patients (24.2%). The intra-operative 3D reveals a high rate of primary screw perforations or near perforations. Immediate change of these screws may lead to a lower rate of secondary screw perforations and, therefore, reduce post-operative complications.

3D rotational fluoroscopy for intraoperative clip control in patients with intracranial aneurysms--assessment of feasibility and image quality.

BackgroundMobile 3D fluoroscopes have become increasingly available in neurosurgical operating rooms. In this series, the image quality and value of intraoperative 3D fluoroscopy with intravenous contrast agent for the evaluation of aneurysm occlusion and vessel patency after clip placement was assessed in patients who underwent surgery for intracranial aneurysms.Materials and methodsTwelve patients were included in this retrospective analysis. Prior to surgery, a 360° rotational fluoroscopy scan was performed without contrast agent followed by another scan with 50 ml of intravenous iodine contrast agent. The image files of both scans were transferred to an Apple PowerMac® workstation, subtracted and reconstructed using OsiriX® free software. The procedure was repeated after clip placement. Both image sets were compared for assessment of aneurysm occlusion and vessel patency.ResultsImage acquisition and contrast administration caused no adverse effects. Image quality was sufficient to follow the patency of the vessels distal to the clip. Metal artifacts reduce the assessability of the immediate vicinity of the clip. Precise image subtraction and post-processing can reduce metal artifacts and make the clip-site assessable and depict larger neck-remnants.ConclusionThis technique quickly supplies images at adequate quality to evaluate distal vessel patency after aneurysm clipping. Significant aneurysm remnants may be depicted as well. As it does not require visual control of all vessels that are supposed to be evaluated intraoperatively, this technique may be complementary to other intraoperative tools like indocyanine green videoangiography and micro-Doppler, especially for the assessment of larger aneurysms. At the momentary state of this technology, it cannot replace postoperative conventional angiography. However, 3D fluoroscopy and image post-processing are young technologies. Further technical developments are likely to result in improved image quality.

Comparaison de l’imagerie peropératoire sur écran plat avec la radiographie postopératoire standard dans la détection des vis intra-articulaires lors de l’usage de plaques d’ostéosynthèse palmaires

ObjectivesTo investigate if intraoperative 3D-flat panel imaging improves the detection of radiocarpal intra-articular screw misplacement (RCSM) in comparison to standard postoperative X-ray. MethodsIn a study on cadaver specimens, we evaluated the sensitivity and specificity to detect RCSM using X-ray, intraoperative 3D-fluoroscopy as well as the Digital Volume Tomography. The gold standard reference was Computed Tomography. ResultsSensitivity for the detection of RCSM for X-ray was 58 % and specificity 88 %. For DVT, the sensitivity to detect RCSM was 88 % and the specificity 53 %. For 3D-fluoroscopy, the sensitivity for RCSM was 68 % and specificity 95 %. When combining the methods, the best performance was found when combining the two intraoperative imaging methods, with a resulting sensitivity of 88 % and a specificity of 73 %. ConclusionsIntraoperative 3D-fluoroscopy and Digital Volume Tomography appear to be at least as sensitive and specific to detect RCSM than the regular postoperative radiography in two planes. However, especially discrete screw misplacements can be missed with either method. Level of evidenceLevel IV. Diagnostic device study.