Intraoperative 3D Imaging Research Articles

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.

Minimally invasive lateral occipitocervical fixation: case series and technique description.

Occipitocervical junction (OCJ) instability is commonly treated with fixation via open posterior approach. The use of intraoperative navigation allows us to perform occipitocervical fixation via minimally invasive approach. We report a series of patients treated with percutaneous occipitocervical fixation, describing the surgical procedure in detail and discussing the technique. We prospectively enrolled 8 patients affected by OCJ instability secondary to trauma and rheumatoid arthritis. Traumatic patients were preoperatively evaluated with CT scan and MRI scan if needed. Rheumatoid arthritis group was evaluated with both CT and MR. Patients underwent percutaneous occipitocervical fixation with the assist of intraoperative 3D imaging and navigation. All patients were functionally and radiologically evaluated pre-, at 6weeks, and at 1year postoperatively. Percutaneous occipitocervical fixation was successfully performed in all of the patients. 33 screws were placed. 29 (87.88%) were placed without any pedicle breach. In 3 (9.09%) screws we observed a minor; and in 1 (3.03%) screw we observed a major pedicle breach. We did not have any postoperative complications. Described method of occipitocervical fixation is a minimally invasive method that has a similar outcome to the open technique. It requires the experience in open techniques and the assist of intraoperative 3D imaging and navigation to be performed efficiently.

Realistic C-arm to pCT registration for vertebral localization in spine surgery

Spine surgeries are vulnerable to wrong-level surgeries and postoperative complications because of their complex structure. Unavailability of the 3D intraoperative imaging device, low-contrast intraoperative X-ray images, variable clinical and patient conditions, manual analyses, lack of skilled technicians, and human errors increase the chances of wrong-site or wrong-level surgeries. State of the art work refers 3D-2D image registration systems and other medical image processing techniques to address the complications associated with spine surgeries. Intensity-based 3D-2D image registration systems had been widely practiced across various clinical applications. However, these frameworks are limited to specific clinical conditions such as anatomy, dimension of image correspondence, and imaging modalities. Moreover, there are certain prerequisites for these frameworks to function in clinical application, such as dataset requirement, speed of computation, requirement of high-end system configuration, limited capture range, and multiple local maxima. A simple and effective registration framework was designed with a study objective of vertebral level identification and its pose estimation from intraoperative fluoroscopic images by combining intensity-based and iterative control point (ICP)–based 3D-2D registration. A hierarchical multi-stage registration framework was designed that comprises coarse and finer registration. The coarse registration was performed in two stages, i.e., intensity similarity-based spatial localization and source-to-detector localization based on the intervertebral distance correspondence between vertebral centroids in projected and intraoperative X-ray images. Finally, to speed up target localization in the intraoperative application, based on 3D-2D vertebral centroid correspondence, a rigid ICP-based finer registration was performed. The mean projection distance error (mPDE) measurement and visual similarity between projection image at finer registration point and intraoperative X-ray image and surgeons’ feedback were held accountable for the quality assurance of the designed registration framework. The average mPDE after peak signal to noise ratio (PSNR)–based coarse registration was 20.41mm. After the coarse registration in spatial region and source to detector direction, the average mPDE reduced to 12.18mm. On finer ICP-based registration, the mean mPDE was finally reduced to 0.36 mm. The approximate mean time required for the coarse registration, finer registration, and DRR image generation at the final registration point were 10 s, 15 s, and 1.5 min, respectively. The designed registration framework can act as a supporting tool for vertebral level localization and its pose estimation in an intraoperative environment. The framework was designed with the future perspective of intraoperative target localization and its pose estimation irrespective of the target anatomy.Graphical abstract

Patient radiation exposure from intraoperative computed tomography in spinal surgery

Intraoperative CT imaging is becoming increasingly used, but often little attention is paid to the underlying radiation exposure to the patient. This work showed that the dosimetrically assessed radiation exposure for cervical and lumbar 3D scans with an intraoperative CT is considerably higher than with a 3D C-arm. Therefore, proper selection of the intraoperative 3D imaging system is essential, and further technological developments and dose-saving protocols are warranted to further reduce patient radiation exposure.

C1 lateral mass screw insertion using cannulated, navigated screws: preliminary results of a novel technique

Purpose The upper cervical spine region is densely populated by neural and vascular structures impeding the approach for fusion surgery. Technological advancement simplify the approach to C1-C2 fusion, thus reduce risks. The current paper purpose is to describe initial experience with a novel technique modification for C1 lateral screw insertion that incorporates cannulated-navigated screw system with intra-operative 3D imaging. Methods A single-center single surgeon database was reviewed to identify all patients who underwent placement of C1 lateral mass screw insertion using the novel technique modification described below, on 2020. This cohort was retrospectively analyzed and compared with a cohort of patients who were operated on by the same surgeon with non-cannulated, navigated screws with intra-operative 3D imaging (O-arm, Medtronic, USA) between 2011 and 2019. Following navigated starting hole and drilling of the C1 lateral mass, a blunt guide-wire is used to palpate the hole and cannulated screw is advanced to the correct position over the wire. After initial purchase, a navigated screw driver is used for final screw depth position. Results Twelve C1 lateral mass screws were inserted in six patients using this novel cannulated-navigated screw placement technique and compared to 24 patients operated using navigated non-cannulated screws. Minimal Estimated Blood Loss (EBL) was recorded in five of six cases undergoing the novel cannulated navigated placement of C1 lateral mass screws. Comparison to non-cannulated cohort demonstrated an EBL of 83CC vs. 354CC (Not significant). Mean surgery time was 97min and 118min for the cannulated-navigated and navigated only procedures (p = 0.03, statistically significant) respectively. In the current cohort, all screws were rated in optimal position and no repositioning procedures were performed. Conclusion The new method presented allows for faster and possibly safer and more accurate C1 lateral mass screw insertion.

Software-Automated Implant Detection for Intraoperative 3D Imaging—First Clinical Evaluation on 214 Data Sets

Previous studies have demonstrated a frequent occurrence of screw/K-wire malpositioning during surgical fracture treatment under 2D fluoroscopy and a correspondingly high revision rate as a result of using intraoperative 3D imaging. In order to facilitate and accelerate the diagnosis of implant malpositioning in 3D data sets, this study investigates two versions of an implant detection software for mobile 3D C-arms in terms of their detection performance based on comparison with manual evaluation. The 3D data sets of patients who had received surgical fracture treatment at five anatomical regions were extracted from the research database. First, manual evaluation of the data sets was performed, and the number of implanted implants was assessed. For 25 data sets, the time required by four investigators to adjust each implant was monitored. Subsequently, the evaluation was performed using both software versions based on the following detection parameters: true-positive-rate, false-negative-rate, false-detection-rate and positive predictive value. Furthermore, the causes of false positive and false negative detected implants depending on the anatomical region were investigated. Two hundred fourteen data sets with overall 1767 implants were included. The detection parameters were significantly improved (p<.001) from version 1 to version 2 of the implant detection software. Automatic evaluation required an average of 4.1±0.4 s while manual evaluation was completed in 136.15±72.9 s (p<.001), with a statistically significant difference between experienced and inexperienced users (p=.005). In summary, version 2 of the implant detection software achieved significantly better results. The time saved by using the software could contribute to optimizing the intraoperative workflow.

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.

Augmented Reality-Assisted Spine Surgery: An Early Experience Demonstrating Safety and Accuracy with 218 Screws.

Prospective cohort study. In spine surgery, accurate screw guidance is critical to achieving satisfactory fixation. Augmented reality (AR) is a novel technology to assist in screw placement and has shown promising results in early studies. This study aims to provide our early experience evaluating safety and efficacy with an Food and Drug Administration-approved head-mounted (head-mounted device augmented reality (HMD-AR)) device. Consecutive adult patients undergoing AR-assisted thoracolumbar fusion between October 2020 and August 2021 with 2-week follow-up were included. Preoperative, intraoperative, and postoperative data were collected to include demographics, complications, revision surgeries, and AR performance. Intraoperative 3D imaging was used to assess screw accuracy using the Gertzbein-Robbins (G-R) grading scale. Thirty-two patients (40.6% male) were included with a total of 222 screws executed using HMD-AR. Intraoperatively, 4 (1.8%) were deemed misplaced and revised using AR or freehand. The remaining 218 (98.2%) screws were placed accurately. There were no intraoperative adverse events or complications, and AR was not abandoned in any case. Of the 208 AR-placed screws with 3D imaging confirmation, 97.1% were considered clinically accurate (91.8% Grade A, 5.3% Grade B). There were no early postoperative surgical complications or revision surgeries during the 2-week follow-up. This early experience study reports an overall G-R accuracy of 97.1% across 218 AR-guided screws with no intra or early postoperative complications. This shows that HMD-AR-assisted spine surgery is a safe and accurate tool for pedicle, cortical, and pelvic fixation. Larger studies are needed to continue to support this compelling evolution in spine surgery.

Intraoperative 3D imaging with cone-beam computed tomography leads to revision of pedicle screws in dorsal instrumentation: a retrospective analysis

BackgroundCorrect positioning of pedicle screws can be challenging. Intraoperative imaging may be helpful. The purpose of this study was to evaluate the use of intraoperative 3D imaging with a cone-beam CT. The hypotheses were that intraoperative 3D imaging (1) will lead to an intraoperative revision of pedicle screws and (2) may diminish the rate of perforated screws on postoperative imaging.MethodsTotally, 351 patients (age 60.9 ± 20.3 a (15–96); m/f 203/148) underwent dorsal instrumentation with intraoperative 3D imaging with 2215 pedicle screws at a trauma center level one. This study first evaluates intraoperative imaging. After this, 501 screws in 73 patients (age 62.5 ± 19.7 a; m/f 47/26) of this collective were included in the study group (SG) and their postoperative computed tomography was evaluated with regard to screw position. Then, 500 screws in 82 patients (age 64.8 ± 14.4 a; m/f 51/31) as control group (CG), who received the screws with conventional 2D fluoroscopy but without 3D imaging, were evaluated with regard to screw position.ResultsDuring the placement of the 2215 pedicle screws, 158 (7.0%) intraoperative revisions occurred as a result of 3D imaging. Postoperative computed tomography of the SG showed 445 (88.8%) screws without relevant perforation (type A + B), of which 410 (81.8%) could be classified as type A and 35 (7.0%) could be classified as type B. Fifty-six (11.2%) screws in SG showed relevant perforation (type C–E). In contrast, 384 (76.8%) screws in the CG were without relevant perforation (type A + B), of which 282 (56.4%) could be classified as type A and 102 (20.4%) as type B. One hundred and sixteen (23.2%) screws in the CG showed relevant perforation (type C–E).ConclusionThis study shows that correct placement of pedicle screws in spine surgery with conventional 2D fluoroscopy is challenging. Misplacement of screws cannot always be prevented. Intraoperative 3D imaging with a CBCT can be helpful to detect and revise misplaced pedicle screws intraoperatively. The use of intraoperative 3D imaging will probably minimize the number of revision procedures due to perforating pedicle screws.

Novel technique for scapulothoracic arthroscopy: A case report of the application of intraoperative 3D imaging.

IntroductionSnapping shoulder syndrome could be effectively treated with scapulothoracic arthroscopy. The excision of the scapular superomedial corner is assumed to help lower the recurrence rate. However, the amount of resection is still controversial. Furthermore, we lack a technique to measure if the resected amount was adequate based only on arthroscopy evaluation.Case study presentationWe describe a 47-year-old man who suffered from severe snapping shoulder syndrome as a consequence of a deformity of the left superomedial scapular corner. The patient had endoscopic bursectomy and superomedial corner resection. Intraoperative three-dimensional CT scans (3D-CT) were used to evaluate the amount of resection. The patient recovered without incident and resumed his usual activities within 30 days following surgery. At the six-month follow-up, there were no recurrent symptoms.ConclusionIntraoperative 3D imaging significantly enhances the safety and efficacy of scapulothoracic arthroscopy. This is a novel technique that, to our knowledge, has not been reported previously in the literature.

Influence de la qualité de la réduction sur les résultats fonctionnels et la qualité de vie après traitement chirurgical des fractures du plateau tibial : étude rétrospective

BackgroundDespite a substantial improvement in the operative treatment of tibial plateau fractures, the surgical procedure remains controversial and is generally challenging, as patients may develop postoperative arthritis and functional impairment of the knee joint. HypothesisIn the surgical treatment of tibial plateau fractures the intraoperative reposition quality has the greatest influence on the postoperative outcome, whereby misalignments of≥2mm lead to a worse result. Patients and methodsForty-one patients with tibial plateau fractures were postoperatively examined. The operative treatment was performed under reduction control using an intraoperative 3D C-arm. The follow-up collective was divided into two groups depending on the intraoperative reduction result. The postoperative results were then evaluated using the following parameters: Lysholm score, Rasmussen score, Tegner score, SF-36 score, range of motion and pain level. ResultsGroup 1 (articular surface incongruencies<2mm) tended to achieve a better result in all scores than group 2 (articular surface incongruencies≥2mm), in the Lysholm score (p=0.039), in the comparison of the range of motion (p=0.012) and the pain level (p=0.039) this was significant. Group 1 achieved an average of 90.71 points (group 2: 78.74) in the Lysholm score. The average range of motion of the knee joint was 138.93° in group 1 (group 2: 127.78°). The average value of the current pain level in group 1 was 1.14 (group 2: 2.63). DiscussionBoth study groups achieved a very good result compared to the available literature. It appears that reduction quality – which can be analyzed with intraoperative 3D imaging – plays the most important role in postoperative quality of life and functional outcome. Intraoperative adjustments of the reduction should therefore be performed on joint surface irregularities with a size above 2mm. Level of evidenceIII; retrospective case control study.

Segmentation of brain tumour in 3D Intraoperative Ultrasound imaging.

Intraoperative ultrasound (iUS), using a navigation system and preoperative magnetic resonance imaging (pMRI), supports the surgeon intraoperatively in identifying tumour margins. Therefore, visual tumour enhancement can be supported by efficient segmentation methods. A semi-automatic and two registration-based segmentation methods are evaluated to extract brain tumours from 3D-iUS data. The registration-based methods estimated the brain deformation after craniotomy based on pMRI and 3D-iUS data. Both approaches use the normalised gradient field and linear correlation of linear combinations metrics. Proposed methods were evaluated on 66 B-mode and contrast-mode 3D-iUS data with metastasis and glioblastoma. The semi-automatic segmentation achieved superior results with dice similarity index (DSI) values between [85.34, 86.79]% and contour mean distance values between [1.05, 1.11]mm for both modalities and tumour classes. Better segmentation results were obtained for metastasis detection than glioblastoma, preferring 3D-intraoperative B-mode over 3D-intraoperative contrast-mode.

How I do it? Uniportal full endoscopic pseudoarthrosis release of left L5/S1 Bertolotti's syndrome under intraoperative computer tomographic guidance in an ambulatory setting.

There is limited literature on technique full endoscopic pseudoarthrosis release of Bertolotti syndrome. Uniportal full endoscopic pseudoarthrosis release technique applies for patients presenting with symptomatic Bertolotti's syndrome. Full-thickness endoscopic drilling is carried out from most ventrolateral margin of pseudoarthrosis articulating with the highest part of sacral ala (PH) point to dorsal medioinferior margin of pseudoarthrosis adjacent to superior articular process (MS) point. Complete pseudoarthrosis release was confirmed with an intraoperative 3D imaging system. The uniportal full endoscopic pseudoarthrosis release is a good alternative to open surgery to release pseudoarthrosis in L5/S1 Bertolotti's syndrome in an ambulatory setting.

85. Comparison of novel machine vision image guidance system with a 3D fluoroscopy-based platform for pedicle screw placement: a randomized prospective study of radiation, accuracy, and cost

<h3>BACKGROUND CONTEXT</h3> The use of image guidance and robotics platforms has increased patient safety, accuracy and operative efficiency and reduced revision rates during pedicle screw placement procedures. However, traditional intraoperative 3D or computational tomography (CT) imaging produces potentially harmful ionizing radiation and increases operative time to register the patient. An image guidance platform using machine vision through high resolution stereoscopic cameras and structured visible light does not use ionizing radiation while it builds a 3D topographical map of the patient's anatomy for navigation use. <h3>PURPOSE</h3> We aimed to compare a novel machine vision image guidance system (MvIGS) system to a widely used 3D fluoroscopy (3D) platform by comparing radiation exposure, and pedicle screw accuracy. <h3>STUDY DESIGN/SETTING</h3> A randomized prospective comparative cohort study of consecutive patients undergoing posterior lumbar instrumented fusion. <h3>PATIENT SAMPLE</h3> Adults diagnosed with a spinal condition requiring surgical treatment and planning to have posterior open lumbar fusion with pedicle screws implanted into 1-4 vertebral levels. <h3>OUTCOME MEASURES</h3> Outcome measures included: mean intraoperative fluoroscopy time and dose, mean preoperative CT dose length product (DLP) and mean day 2 postoperative CT DLP, pedicle screw accuracy and rate of revision surgery. <h3>METHODS</h3> Patients were randomized 1:1 to MvIGS or 3D and underwent posterior lumbar instrumented fusion. Radiation doses were recorded from pre- and postoperative CT and intraoperative fluoroscopy. Independent blinded radiologists reviewed pedicle screw accuracy. <h3>RESULTS</h3> A total of 303 (154 MvIGS, 149 3D) pedicle screws were placed in 63 patients (33 MvIGS, 30 3D) over the 12-month study period. Mean age and indication for surgery were similar between both groups. Mean intraoperative fluoroscopy time and doses were significantly reduced in MvIGS compared to 3D (5.2±4.1s vs 79.6±23.3s, p<0.001 and 133.0±215.8cGycm2 vs 3704.1±1640.5cGycm2, p<0.001, respectively). This represents a relative reduction of 93.5% in the total intraoperative time and 96.4% reduction in the total dose. Mean preoperative CT DLP and mean day 2 postoperative CT DLP were significantly reduced in MvIGS compared to 3D (590.8±389.6mGy*cm vs 1008.9±616.3mGy*cm, p<0.001 and 518.1±205.6mGy*cmvs 958.7±449.6mGy*cm, p<0.001, respectively). This represents a relative reduction of 41.4% and 46.0% relative reduction in the preoperative CT dose and postoperative total DLP, respectively. The MvIGS group required an average of 1.2 registrations each case with an average of 2447 (SD=961.3) data points registered with mean registration time of 106s (SD=52.1s). A rapid re-registration mechanism was utilized in 22% (n=7/33) of cases. Pedicle screw accuracy was high in both groups MvIGS (98.7%) vs 3D (97.3%) with no pedicle breach >2mm in either group (p>0.001). No neurovascular injuries occurred, and no patients needed return to theatre for screw repositioning. <h3>CONCLUSIONS</h3> Both MvIGS and 3D image guidance platforms demonstrated high accuracy for pedicle screw placement. MvIGS demonstrated significant reduction of 93.5% and 96.4% in intraoperative radiation time and dose. MvIGS may provide similar accuracy to contemporary image guidance platforms without requiring 3D fluoroscopy or radiolucent operating tables. Reducing registration times and the need for specialized equipment may significantly reduce operating room costs. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Utility of 3-Dimensional Intraoperative Imaging in Pelvic and Acetabular Fractures: A Network Meta-Analysis.

Successful surgical management of pelvic ring and acetabular fractures requires technical expertise to achieve an accurate reduction and stable fixation. The use of 3-dimensional (3D) intraoperative imaging (3DIOI) as an assessment tool has led to improved reduction and placement of implants. The purpose of this study was to assess the utility of using 3DIOI in the management of acetabular and pelvic fractures on the basis of outcomes reported in the literature. A literature search was performed using PubMed, the Cochrane Database of Systematic Reviews (CDSR), and Google Scholar using key terms. A network meta-analysis conducted using the frequentist approach allowed for statistical analysis of reported outcomes regarding screw position (in mm), fracture reduction (in mm), and complications. A total of 9 studies were included in this analysis. When compared with conventional radiography, the mean radiation dose (in cGy·cm2) was significantly higher in 3DIOI (mean difference, 82.72; 95% confidence interval [CI], 21.83 to 143.61; p = 0.007). Use of 3DIOI yielded a 93% lower risk of developing medical complications (odds ratio [OR], 0.07; 95% CI, 0.02 to 0.35; p = 0.014). Use of 3DIOI yielded higher odds of achieving accurate screw placement (OR, 4.21; 95% CI, 1.44 to 12.32; p = 0.008) and perfect reduction (OR, 2.60; 95% CI, 1.19 to 5.68; p = 0.016). In ranking the imaging modalities, 12 of the 13 parameters analyzed were in favor of 3DIOI over conventional fluoroscopy and 2D navigation imaging. Current literature supports the use of 3DIOI because of the decreased rates of misplaced implants, malreduced fractures, complications, and subsequent revision operations. The use of 3DIOI allows for improved visualization of pelvic anatomy when repairing pelvic and acetabular fractures, and helps surgeons to achieve favorable surgical outcomes. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Does the use of intraoperative CT scan improve outcomes in Orthopaedic surgery? A systematic review and meta-analysis of 871 cases

BackgroundIntraoperative imaging is frequently made use of in Orthopaedic surgery. Historically, conventional 2-dimensional fluoroscopy has been extensively used for this purpose. However, 2D imaging falls short when it is required to visualise complex anatomical regions such as pelvis, spine, foot and ankle etc. Intraoperative 3D imaging was introduced to counter these limitations, and is increasingly being employed in various sub-specialities of Orthopaedic Surgery. ObjectivesThis review aims to outline the clinical and radiological outcomes of surgeries done under the guidance of intraoperative 3D imaging and compare them to those done under conventional 2D fluoroscopy. MethodsThree electronic databases (PubMed, Embase and Scopus) were searched for relevant studies that directly compared intraoperative 3D imaging with conventional fluoroscopy. Case series on intraoperative 3D imaging were also included for qualitative synthesis. The outcomes evaluated included accuracy of implant placement, mean surgical duration and rate of revision surgery due to faulty implants. ResultsA total of 31 studies from sub-specialities of spine surgery, pelvi-acetabular surgery, foot and ankle surgery and trauma surgery, having data on a total of 658 patients were analysed. The study groups which had access to intraoperative 3D imaging was found to have significantly increased accuracy of implant positioning (Odds Ratio 0.35 [0.20, 0.62], p = 0.0002) without statistically significant difference in mean surgical time (p = 0.57). Analysis of the studies that included clinical follow up showed that the use of intraoperative 3D imaging led to a significant decrease in the need for revision surgeries due to faulty implant placement. ConclusionThere is sufficient evidence that the application of intraoperative 3D imaging leads to precise implant positioning and improves the radiological outcome. Further research in the form of prospective studies with long term follow up is required to determine whether this superior radiological outcome translates to better clinical results in the long run.

Intraoperative 3D imaging in intraarticular tibial plateau fractures - Does it help to improve the patients\u2019 outcomes?

BackgroundIn tibial plateau fractures (TPF) the restoration of an anatomical joint surface as well as an exact subchondral screw position for postoperative stability is crucial for the outcome.The aim of this study was to determine whether the additional use of an intraoperative 3D imaging intensifier (3D) might help to improve the outcome of complex TPF.MethodsWe performed a retrospective case-control study of a level 1 trauma center. Patients with AO/OTA 41 B3 and C-TPF operated on using a 3D imaging intensifier between November 2015 and December 2018 (3D group) were included. The outcomes of this patients were compared to patients operated without 3D imaging between January 2005 to December 2014 (2D group). The comparison of the groups was performed by matched pair analysis. The functional outcome of both groups was measured by KOOS and Lysholm Score after a follow-up period of at least 12 months. Operation time, infections and postoperative revisions were registered.ResultsIn total, 18 patients were included in the 3D group (mean age: 51.0± 16.4 years; 12 females) and an equal number of matching partners from the 2D group (mean age: 50.3± 15.2 years; 11 females) were found (p=0.82; p=0.79). We found 9x B3, 2x C1, 1x C2, 6x C3 fractures according to AO/OTA for each group (p=1.00) with comparable ASA score (p=0.27). The mean operation time was 127.9± 45.9 min and 116.1± 45.7 min for the 3D and 2D group (p=0.28). The mean follow-up time was 20.9± 10.7 months for the 3D and 55.5± 34.7 months for the 2D group (p< 0.001). For the 3D group a mean Lysholm overall score of 67.4± 26.8 and KOOS overall score of 72.6± 23.5 could be assessed. In contrast, a mean Lysholm overall score of 62.0± 21.4 and KOOS overall score of 65.8± 21.6 could be measured in the 2D group (p=0.39; p=0.31). Thereby, functional outcome of the 3D group showed a significant higher KOOS Sport/Rec sub score of 54.7± 35.0 in comparison to the 2D group with 26.7± 31.6 (p= 0.01). Postoperative revisions had to be performed in 27.8% of cases in both groups (p=1.00). Due to the 3D imaging an intraoperative revision was performed in 33.3% (6/18).ConclusionIn our study we could show that re-reduction of the fracture or implant re-positioning were performed in relevant numbers based on the 3D imaging. This was associated with a midterm clinical benefit in regard to better KOOS Sport/Rec scores.Trial registrationAZ 488 /20-ek

Assessment of pedicle size in patients with scoliosis using EOS 2D imaging: a validity and reliability study

PurposeFree-hand pedicle screw insertion methods are widely used for screw insertion during scoliosis surgery. Preoperative knowledge about the pedicle size helps to maximize screw containment and minimize the risk of pedicle breach. Radiographs taken by a biplanar low-dose X-ray device (EOS) have no divergence in the vertical plane. The criterion validity and reliability of preoperative EOS images for pedicle size measurements in patients with idiopathic scoliosis (IS) was investigated in this study.MethodsSixteen patients who underwent surgical treatment for IS were prospectively included. Intra- and extracortical pedicle height and width measurements on EOS images were compared with reconstructed intra-operative 3D images of the isthmus of included pedicles. Secondly, intra- and interobserver reliability of pedicle size measurements on EOS images was determined.ResultsThe total number of analyzed pedicles was 203. The correlation between the EOS and 3D scan measurements was very strong for the intra- and extracortical pedicle height and strong for the intra- and extracortical pedicle width. There are, however, significant, but likely clinically irrelevant differences (mean absolute differences < 0.43 mm) between the two measure methods for all four measurements except for extracortical pedicle height. For pedicles classified as Nash–Moe 0, no significant differences in intra- and extracortical pedicle width were observed. Both intra- and interobserver reliability was excellent for all pedicle size measurements on EOS images.ConclusionThe results of this study indicate a good validity and reliability for pedicle size measurements on EOS radiographs. Therefore, EOS radiographs may be used for a preoperative estimation of pedicle size and subsequent screw diameter in patients with IS.

Influence of reduction quality on functional outcome and quality of life in the surgical treatment of tibial plateau fractures: A retrospective cohort study

BackgroundDespite a substantial improvement in the operative treatment of tibial plateau fractures, the surgical procedure remains controversial and is generally challenging, as patients may develop postoperative arthritis and functional impairment of the knee joint. HypothesisIn the surgical treatment of tibial plateau fractures the intraoperative reposition quality has the greatest influence on the postoperative outcome, whereby misalignments of≥2mm lead to a worse result. Patients and methodsForty-one patients with tibial plateau fractures were postoperatively examined. The operative treatment was performed under reduction control using an intraoperative 3D C-arm. The follow-up collective was divided into two groups depending on the intraoperative reduction result. The postoperative results were then evaluated using the following parameters: Lysholm score, Rasmussen score, Tegner score, SF-36 score, range of motion and pain level. ResultsGroup 1 (articular surface incongruencies<2mm) tended to achieve a better result in all scores than group 2 (articular surface incongruencies≥2mm), in the Lysholm score (p=0.039), in the comparison of the range of motion (p=0.012) and the pain level (p=0.039) this was significant. Group 1 achieved an average of 90.71 points (group 2: 78.74) in the Lysholm score. The average range of motion of the knee joint was 138.93° in group 1 (group 2: 127.78°). The average value of the current pain level in group 1 was 1.14 (group 2: 2.63). DiscussionBoth study groups achieved a very good result compared to the available literature. It appears that reduction quality – which can be analyzed with intraoperative 3D imaging – plays the most important role in postoperative quality of life and functional outcome. Intraoperative adjustments of the reduction should therefore be performed on joint surface irregularities with a size above 2mm. Level of evidenceIII; retrospective case control study.

The use of an O-arm in endonasal endoscopic operations of the skull base

BackgroundEndoscopic endonasal transsphenoidal approaches are broadly used nowadays for a vast spectrum of pathologies sited in the anterior and middle cranial fossa. The usage of neuronavigation systems (neuronavigation) in these surgeries is crucial for improving orientations deeply inside the skull and increasing patient safety.MethodsThe aim of this study was to assess the use of optical neuronavigation, together with an intraoperative O-arm O2 imaging system, in a group of patients with hypophyseal adenoma that underwent a transnasal transsphenoidal surgery, and correlate the accuracy and its deviation during the navigational process against the use of conventional neuronavigation that uses preoperative MRI and CT scans. The overall group consisted of six patients, between 39 and 78 years old, with a diagnosis of hypophyseal adenoma. Patients were treated with an endoscopic transsphenoidal technique and all of them underwent preoperative MRI and CT scans of the brain. These images were used in the neuronavigation system StealthStation S7® during the surgery, where we defined two bony anatomical landmarks, such as a vomer or the origin of an intrasphenoidal septum, in each operated patient. The tip of the navigational instrument, under endoscopic control, pointed to these landmarks and the distance between the tip and the bony structure was measured on the neuronavigation system. Afterwards, intraoperative 3D x-ray imaging was performed via the mobile system O-arm O2® system with automatic transfer into the navigational system. Under endoscopic guidance, we localized the identical bony anatomical landmarks used in the previous measurement and re-measured the distance between the tip and bony landmark in images acquired by the O-arm. The results of both measurements were statistically compared.ResultsThe mean error of accuracy during conventional neuronavigation with usage of preoperative CT and MRI scans was 2.65 mm. During the neuronavigation, with utilization of intraoperative 3D O-arm images, the mean error of accuracy 0 mm. These mean errors of accuracy (both measurement methods were compared by nonparametric Wilcoxon test) had a statistically significant difference (p = 0.043).ConclusionsBased on this preliminary clinical study, we conclude that the O-arm is capable of providing intraoperative x-ray 3D images in sufficient spatial resolution in a clinically feasible acquisition. The mean error of accuracy during intraoperative navigation, based on 3D O-arm scans at the skull base, is significantly lower compared to the usage of navigation using conventional presurgical CT and MRI images. This suggests the suitability of this method for utilization during endoscopic endonasal skull base approaches.