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Virtual surgical planning and three-dimensional (3D) printing have broadened the horizons of oral and maxillofacial surgery, including orthognathic surgery. 3D-printed personalized surgical guide and patient-specific implant (PSI) not only serve to guide accurate osteotomies and as a good fitting of osteosynthesis plate, but more importantly define a revolutionary waferless approach concept that is totally different from the conventional wafer-guided jaw fixation technique. This review discusses the limitations of the conventional orthognathic approach, and how PSI may overcome these limitations, improve accuracy, and bring additional benefits in the execution of orthognathic surgery.

Background Percutaneous pedicle screw (PPS) placements in the lumbosacral spine generally rely on fluoroscopy at the expense of radiation exposure. Our accumulated experience in open PS placements without fluoroscopic guidance realized a consistent shift toward PPS insertion with newly developed devices, which require neither fluoroscopy nor navigation. We wish to report our new technique and evaluations of its accuracy. Methods Our equipment consisted of a pedicle targeting tool to identify and escort the cannulated awl to the correct starting point for cortical bone perforation and a cannulated awl-probe system with a guidewire to maintain the optimal position throughout the subsequent surgical steps. The surgeon could advance the blunt-tipped probe searching for the cancellous bone track using tactile feedback as experienced in open techniques. A 2-year period of transition from a free-hand (1169 screws in 286 patients) to the new PPS technique (1933 screws in 413 patients) allowed accuracy comparison between the two procedures using postoperative CT scans. Results Compared with the open-group, the PPS-group showed a lower rate of fully contained intrapedicular PS placements at L1 through S1, as a whole (90.7% vs 85.4%), but not at L4 through S1 (89.9% vs 90.2%). Less-accurate PPS placements at upper than lower lumbar spines in part reflect intended pedicle perforations laterally as a trade-off for avoiding facet violation immediately above the most cephalad screw. The PPS-group also had a higher incidence of PS-related transient nerve root complications (0% vs 1.7%). These values for the PPS-group, however, fell within those previously reported for free-hand or fluoroscopy techniques. Conclusions Our new PPS technique, although useful for eliminating the potential risk of repeated radiation exposure, fell short of reaching the accuracy of the free-hand technique. Nerve integrity monitoring with PS stimulation, which we currently use, will help further improve the technical precision. Study design Original Article. The study was approved by our institutional review boad (2,019,231).

Zygomaticomaxillary complex fractures involve four fracture ends. It is difficult to fully expose the operative area through a main coronal incision, an intraoral incision, and an eyelid incision. To address the partial visual field loss in craniofacial fracture reduction, we attempted to use an augmented reality (AR) navigation system.Patients with zygomaticomaxillary complex fractures underwent three-dimensional (3D) computed tomography (CT) modeling before surgery, and preoperative plans were designed. The control team used traditional optical navigation to perform the surgery. The experimental team used an AR navigation system. From May 2019 to December 2019, 10 patients with zygomaticomaxillary complex fractures were included in this study. Data were collected after surgery and analyzed.There was a significant difference between the two groups in the fracture point error (1.35 vs. 1.61, P = 0.02) and fracture reduction time (15.40 vs. 20.40, P = 0.03). However, there was no difference in the operative duration (6.60 vs. 6.65, P = 0.92), blood loss volume (620.00 vs. 580.00, P = 0.83), or incidence of complications.The AR navigation system used by the research team has good auxiliary effects for reducing zygomaticomaxillary complex fractures. The new surgical method has better accuracy and a shorter reduction time than the traditional surgical method.

We aimed to produce a narrative review of planning orthognathic surgery, chronologically. Also, to present flaws of methods and the future of orthognathic surgery planning. The search was carried out mainly in PubMed, SCOPUS, Embase, and Cochrane databases. Also was complemented by manual search in reference lists from identified studies and in grey literature. The first orthognathic surgery was reported in 1849, and it took more than a century for the development of the traditional orthognathic 2D planning. Besides the advances, surgeons observed failures and lacks on 2D method in representing with reliability the facial and maxillary tridimensional structure (3D). With technological developments in 90s and 2000s, methodological improvements were granted, and the 3D protocol was created. The CASS and Charlotte protocols were the earliest 3D planning protocols conceived. Since then, some steps were simplified, and new technologies are being developed and added to create a more reliable and precise way of planning orthognathic surgery.

Statement of problem The accuracy of single implant placement is critical, as errors may cause problems with vital structures intraoperatively, as well as postoperatively with the prostheses. These issues may be exacerbated in complete-arch edentulous treatments requiring relative accuracy among multiple implants, particularly with prefabricated prosthetic structures. Purpose The purpose of this clinical study was to determine the accuracy of dental implant placement by using haptic robotic guidance in completely edentulous participants. Material and methods In a prospective single-arm clinical study, 5 qualified participants elected to receive dental implants placed by using haptic robotic guidance to restore either the maxillary or mandibular arch, or both, with complete-arch implant-supported prostheses. Three dual-arch participants and 2 single-arch participants resulted in 38 endosteal dental implants being placed. A virtual preoperative restorative and surgical plan was created before surgery. This plan was matched to the surgical workspace on the day of surgery by using a bone-mounted fiducial splint fabricated from a cone beam computed tomography (CBCT) scan. Intraoperatively, the surgeons maneuvered a handpiece attached to the robotic guidance arm, osteotomies were created with a haptically constrained handpiece, and the implants were placed with 3-dimensional haptic constraints as per the virtual plan. Postoperative CBCT scans allowed the evaluation of the deviations of the actual implant placement relative to the plan. Results Twenty-three implants were placed in the mandible and 15 in the maxilla. The mean ±standard deviation global angular deviation was 2.56 ±1.48 degrees, while the crown of the placed implant showed a deviation from the plan of 1.04 ±0.70 mm and the apex of 0.95 ±0.73 mm. The signed depth deviation was 0.42 ±0.46 mm proud. No adverse events were reported. Conclusions This clinical series for treating completely edentulous patients by using haptic robotic guidance was found to be safe and accurate. While further longer-term clinical studies are necessary to measure outcomes and to assess differences as compared with nonrobotic implementations, haptic robotic preparation appears to confer additional intraoperative advantages over other techniques for treating completely edentulous arches.

Mastoidectomy involves drilling the temporal bone while avoiding the facial nerve, semicircular canals, sigmoid sinus, and tegmen. Optical topographic imaging (OTI) is a novel registration technique that allows rapid registration with minimal navigational error. To date, no studies have examined the use of OTI in skull-base procedures.In this cadaveric study, 8 mastoidectomies were performed in 2 groups-4 free-hand (FH) and 4 OTI-assisted mastoidectomies. Registration accuracy for OTI navigation was quantified with root mean square (RMS) and target registration error (TRE). Procedural time, percent of mastoid resected, and the proximity of the mastoidectomy cavity to critical structures were determined.The average RMS and TRE associated with OTI-based registration were 1.44 mm (±0.83 mm) and 2.17 mm (±0.89 mm), respectively. The volume removed, expressed as a percentage of the total mastoid volume, was 37.5% (±10.2%) versus 31.2% (±2.3%), P = 0.31, for FH and OTI-assisted mastoidectomy. There were no statistically significant differences between FH and OTI-assisted mastoidectomies with respect to proximity to critical structures or procedural time.This work is the first examining the application of OTI neuronavigation in lateral skull-base procedures. This pilot study revealed the RMS and TRE for OTI-based navigation in the lateral skull base are 1.44 mm (±0.83 mm) and 2.17 mm (±0.89 mm), respectively. This pilot study demonstrates that an OTI-based system is sufficiently accurate and may address barriers to widespread adoption of navigation for lateral skull-base procedures.

The surgery-first concept is becoming increasingly popular in orthognathic surgery since it offers major advantages such as a reduction of treatment duration and an increase in patient satisfaction by eliminating phases of presurgical orthodontic decompensation. Here, we present a novel interdisciplinary pathway of a fully virtual orthodontic-surgical planning concept in a surgery-first setting using a 3D-printed cutting guide and a customised maxillary implant for the Le Fort I osteotomy as well as a CAD/CAM-based stereolithographic final splint. Patient data from cone-beam computed tomography of the skull and a full arch dental scan were processed using the OnyxCeph

Systematic Review.To elucidate treatment modalities and outcomes of patients with traumatic cervical spondyloptosis (TCS).Traumatic cervical spondyloptosis (TCS) is rare and typically leads to devastating neurological injury. Management strategies vary from case to case.A systematic review of the literature identified cases of adult TCS, and data was analyzed to characterize the patient population and to assess factors that influenced clinical outcome. In addition, an illustrative case is presented in which closed reduction of a severe C7-T1 spondyloptosis injury was guided with the use of cone beam computerized tomography (O-Arm) to overcome difficulties with visualizing the cervicothoracic junction region.In addition to our case, we identified 52 cases of adult TCS from 34 articles. Patient age ranged from 18 to 73 (average 45.6) with male a predominance (n = 37, 71.2%). Neurological function on presentation was most commonly ASIA E (34.6%), followed by ASIA D (21.2%) and ASIA A (19.2%). The most frequently affected levels were C7-T1 (44.2%) followed by C6-7 (33.0%). Closed reduction was attempted in 42 (80.8%) patients. A total of 49 (94.2%) patients underwent surgical treatment, with 31 (63.3%) undergoing single-approach procedures. The presence of neurological injury, cervical level of injury, and age were not significant predictors of successful closed reduction. Similarly, successful closed reduction, age, cervical level of injury, and neurological injury were not predictors of a single-approach treatment.TCS is rare and most frequently appears at or near the cervicothoracic junction and in males. The presentation is typically that of severe neurological injury, but partial neurological recovery occurs in many patients. No predictors of successful closed reduction or single approach surgery are identified. We postulate that the use of intraoperative multiplanar imaging technology like the O-Arm may enhance the ability to achieve a successful closed reduction given the predilection for the injury to occur at the cervicothoracic junction. Prospective study of the durability of constructs by single or combined approaches is warranted.

Navigation-assisted surgery is the gold standard for complex reconstructive procedures of the midface and facial skeleton, and artificial and anatomical landmarks are often used for reference. The correct identification of these landmarks before surgery is crucial for the accuracy of the navigation system. This study aimed to investigate the human errors in reference point placement. This retrospective study investigated 228 reference-point positions in 51 cases where navigation was utilized. The discrepancies between the actual reference point-position and manually planned preoperative reference points were quantified using Brainlab iPlanCMF 3.0.6. The referencing methods used in these cases included dental registration splints, osteosynthesis materials, anatomical landmarks, and combinations of these methods. The average discrepancy in the actual and manually planned reference points was 0.29 ± 0.41 mm. The use of anatomical landmarks demonstrated a significantly lower deviation (p 0.05), although the differences between the errors in reference-point placement using dental registration splints, osteosynthesis materials, or combinations of these methods were not statistically significant. The frequency of misplacement of reference points was significantly higher than expected. These errors might have been caused by human bias during manual placement of the points or intraoperative difficulties caused by extensive metal artifacts. Thus, we postulate that the surgical personnel involved in planning navigation-assisted surgery should undergo intensive training. The development of new referencing methods that are less susceptible to these causes of error might help overcome human bias.

Accurate reduction is of vital importance in the treatment of zygomaticomaxillary complex (ZMC) fractures. Computer-assisted navigation systems (CANS) have been employed in ZMC fractures to improve the accuracy of surgical reduction. However, randomized controlled trials on this subject are rare and the benefits of CANS remain controversial. The aim of this study was to compare reduction errors between navigation-aided and conventional surgical treatment for ZMC fractures. Thirty-eight patients with unilateral type B ZMC fractures were enrolled. Preoperative computed tomography data were imported into ProPlan software for virtual surgical planning. Open reduction and internal fixation was performed with CANS (experimental group) or without CANS (control group). Postoperative computed tomography scans were obtained to examine the difference between surgical planning and the actual postoperative outcome, namely reduction errors. The median translational reduction errors in the X, Y, and Z axes were 0.80 mm, 0.40 mm, and 0.80 mm, respectively, in the experimental group and 0.53 mm, 0.86 mm, and 0.83 mm, respectively, in the control group (P0.05). The median rotational reduction errors in pitch, roll, and yaw were 0.92°, 2.47°, and 1.54°, respectively, in the experimental group and 1.45°, 3.68°, and 0.76°, respectively, in the control group (P0.05). In conclusion, compared with conventional reduction surgery, navigation-aided surgery showed no significant improvement in reduction accuracy in the treatment of type B ZMC fractures (Chinese Clinical Trial Registry, registration number ChiCTR1800015559).

A new technique of guided implant surgery is presented. A conventional complete denture is converted into both tomographic and surgical guides and later into an interim implant-supported fixed prosthesis. A plate derived from a computed tomography scan becomes the physical link between the virtual planning and tube positioning device. Furthermore, the interim placement of mini-implants adjacent to the symphysis region stabilizes the guide throughout the guided surgery. This technique reduces treatment time and costs.

Patient-specific instrumentation (PSI) was developed to produce more accurate alignment of components and consequently improve clinical outcomes when used in total knee arthroplasty. We compare radiological accuracy and clinical outcomes at a minimum of 5-year follow-up between patients randomized to undergo total knee arthroplasty performed using PSI or traditional cutting block techniques.This multicenter, randomized control trial included patients blinded to the technique 1used. Outcome measures were coronal alignment measured radiologically, Euroqol-5D, Oxford knee score, and International Knee Society Score measured at 1- and 5-year follow-up.At a minimum 5-year follow-up, there were 38 knees in the PSI group and 39 in the conventional instrumentation group for analysis. Baseline demographics and clinical outcome scores were matched between groups. Overall, there was no significant difference in the coronal femoral angle (P = .59), coronal tibial angle (P = .37), tibiofemoral angle (P = .99), sagittal femoral angle (P = .34), or the posterior tibia slope (P = .12) between knees implanted using PSI and those implanted with traditional cutting blocks. On the measurement of coronal alignment, intraobserver reliability tests demonstrated substantial agreement (k = 0.64). Clinical outcomes at both 1-year and 5-year follow-up demonstrated statistically significant and clinically relevant improvement in scores from baseline in both groups, but no difference could be detected between the Euroqol-5D (P = .78), Oxford knee score (P = .24), or International Knee Society Score (P = .86) between the 2 groups.This study has shown no additional benefit to PSI in terms of improved alignment or functional outcomes at minimum 5-year follow-up over traditional techniques.

This pilot study was undertaken to evaluate the safety, performance, and usability of the Xvision-Spine (XVS) System (Augmedics, Arlington Heights, IL) during open spinal fixation procedures in patients requiring pedicle screw placement in the lumbosacral spine.The XVS System is an augmented reality head-mounted display (HMD) based on a computer navigation system designed to assist surgeons in accurately placing pedicle screws. It uses an HMD-mounted tracking camera to provide optical tracking technology, and provides the surgeon a translucent direct near-eye display of the navigated surgical instrument's location relative to the computed tomographic image. We report the preliminary results of a prospective series of all consecutive patients who underwent augmented reality-assisted pedicle screw placement in the lumbosacral vertebrae at 3 institutions. Clinical accuracy for each pedicle screw was graded with Gertzbein-Robbins scores by 2 independent and blinded neuroradiologists.The 19 study participants included 8 men and 11 women with a mean age of 59.13 ± 12.09 and 59.91 ± 12.89 years, respectively. Seventeen procedures were successfully completed via the XVS System. Two procedures were not completed due to technical issues with the system's intraoperative scanner. A total of 86 screws were inserted. The accuracy of the XVS System was 97.7%.The XVS System's performance in accurate placement of pedicle screws in the lumbosacral vertebrae had an overall accuracy of 97.7%. These preliminary results were comparable to the accuracy of other manual computer-assisted navigation systems reported in the literature.

Printed cutting and repositioning templates could bring superior accuracy when transferring a maxillary plan to the operating room compared to a wafer-based method. However, the effect of these methods in different types of cases is inconclusive. The objective of the study was to compare the accuracy when using printed occlusal splints versus templates in simple and complicated cases.A retrospective cohort study design was used. Complicated cases were defined as cases involving impaction movement of more than 2 mm, occlusal plane canting of more than 3°, or midline discrepancies of more than 2.5 mm. Other cases were simple cases. Enrolled patients were randomly allocated into the digital occlusal splint (DOS) cohort and the digital templates (DT) cohort. The outcome variable was surgical accuracy, defined as the average deviation between the planned and postsurgical locations of bilateral maxillary central incisors, canines, first premolars, and first molars. Predictor variables were 1) operative complexity, simple versus complicated; and 2) technique for positioning the maxilla, DOS versus DT. Covariates were age and planned surgical movement. Two-way analysis of variance was used.Seventy patients were included in this study. Thirty-three were in the DOS cohort, and 37 in the DT cohort. The average deviation was significantly smaller in the complicated cases in the DT cohort (1.37 mm; 95% confidence interval, 1.08-1.66 mm) than that in the DOS cohort (2.47 mm; 95% confidence interval, 1.92-3.02 mm) (P = .002). The deviations in anteroposterior direction of complicated cases in the DT cohort were smaller than the corresponding values of the DOS cohort (P = .035). There is no significant difference between the deviation values of simple and complicated cases using templates (P = .116).These results indicate that in complicated cases, printed guiding templates exhibit better accuracy for repositioning the maxilla than printed occlusal splints, and the effect of templates in different cases proved to be stable.

The aim of this study is to compare the accuracy of maxilla positioning in orthognathic surgery with the use of custom-made devices (cutting guides and patient-fitted osteosynthesis plates) comparing to CAD/CAM splints. A prospective randomized study was performed. Patients with dentofacial deformities undergoing orthognathic surgery were compared, using customized guides (experimental group) vs. CAD/CAM surgical splints (control group) for the repositioning of the upper maxilla. Preoperative and postoperative CT scans were used to compare positioning and fixation of the maxilla in the three planes of space. A total of 30 patients were included in the study (15 patients in each study group). The mean error obtained with customized guides was 0.8 mm (range 0.1-1.9) in the anterior-posterior axis, 0.4 mm (range 0-1.4) in the vertical axis and 0.2 mm (range 0-1.1) in the horizontal axis. There were statistically significant differences in the anterior-posterior and vertical axes in favour of the customized implants, whereas there were no differences in the horizontal plane. Furthermore, there was a mean reduction of the operative time of 36.5 min in the experimental group. Within the limitations of the study it seems that patient specific surgical guides should be preferred when accuracy of repositioning of the maxilla and saving operative time are the priority.

Three-dimensional printing has introduced new manufacturing methods. However, information on the influence of the specific printing technology, material, sterilization, and the comparison between printing and milling on the accuracy of surgical guides is lacking.The purpose of this in vitro study was to evaluate the influence of the manufacturing method (printing and milling), printing technology stereolithography (SLA) and digital light processing (DLP), material, and sterilization on the accuracy of digitally designed surgical implant guides.Resin patient replicas with a single edentulous space were used to place 132 implants with digitally designed surgical guides. The accuracy of postoperative implant position was analyzed for the manufacturing method (printing and milling), resin materials, and preoperative autoclaving. To determine 3D accuracy, angular displacement, mean horizontal crestal, apical displacement, and the linear vertical displacement at the apex were calculated separately for each group (n=12). In addition, the surgical guides were qualitatively analyzed by using field emission scanning electron micrograph.The postoperative angular deviation ranged from 0.76 ±0.52 degrees (Rapidshape D20II with NextDent SG) to 2.43 ±0.64 degrees (Form2 with NextDent SG) (P.001). Linear horizontal displacement at the crest was smallest for Rapidshape D20II with 3Delta Guide (0.27 ±0.08 mm) and highest for Form2 with NextDent SG (0.54 ±0.10 mm) (P.001). Linear horizontal displacement at the apex ranged from 0.36 ±0.10 mm (SolFlex 350 with V-Print SG) to 0.89 ±0.32 mm (Form2 with NextDent SG) (P.001). Considering the vertical position displacement was no more than 0.43 ±0.07 mm (Form2 with NextDent SG) short of the apex, none of the implant tips were displaced apically. Preoperative autoclaving differentially impaired the accuracy of surgical guides.The specific manufacturing technique, the 3D printing device, the resin material, and the application of preoperative sterilization all affected the accuracy of the postoperative implant position. Irrespective of the manufacturing method, all implants were placed within the commonly accepted safety distance.

Navigation systems for spinal fusion surgery rely on intraoperative computed tomography (CT) or fluoroscopy imaging. Both expose patient, surgeons and operating room staff to significant amounts of radiation. Alternative methods involving intraoperative ultrasound (iUS) imaging have recently shown promise for image-to-patient registration. Yet, the feasibility and safety of iUS navigation in spinal fusion have not been demonstrated.To evaluate the accuracy of pedicle screw insertion in lumbar and thoracolumbar spinal fusion using a fully automated iUS navigation system.Prospective porcine cadaver study.Five porcine cadavers were used to instrument the lumbar and thoracolumbar spine using posterior open surgery. During the procedure, iUS images were acquired and used to establish automatic registration between the anatomy and preoperative CT images. Navigation was performed with the preoperative CT using tracked instruments. The accuracy of the system was measured as the distance of manually collected points to the preoperative CT vertebral surface and compared against fiducial-based registration. A postoperative CT was acquired, and screw placements were manually verified. We report breach rates, as well as axial and sagittal screw deviations.A total of 56 screws were inserted (5.50 mm diameter n=50, and 6.50 mm diameter n=6). Fifty-two screws were inserted safely without breach. Four screws (7.14%) presented a medial breach with an average deviation of 1.35±0.37 mm (all2 mm). Two breaches were caused by 6.50 mm diameter screws, and two by 5.50 mm screws. For vertebrae instrumented with 5.50 mm screws, the average axial diameter of the pedicle was 9.29 mm leaving a 1.89 mm margin in the left and right pedicle. For vertebrae instrumented with 6.50 mm screws, the average axial diameter of the pedicle was 8.99 mm leaving a 1.24 mm error margin in the left and right pedicle. The average distance to the vertebral surface was 0.96 mm using iUS registration and 0.97 mm using fiducial-based registration.We successfully implanted all pedicle screws in the thoracolumbar spine using the ultrasound-based navigation system. All breaches recorded were minor (2 mm) and the breach rate (7.14%) was comparable to existing literature. More investigation is needed to evaluate consistency, reproducibility, and performance in surgical context.Intraoperative US-based navigation is feasible and practical for pedicle screw insertion in a porcine model. It might be used as a low-cost and radiation-free alternative to intraoperative CT and fluoroscopy in the future.

The aim of this study was to evaluate the accuracy of navigation-assisted maxillofacial reconstruction and to identify the predictors of the clinical outcomes. A total of 112 patients who underwent navigation-assisted maxillofacial reconstruction with free flaps between 2014 and 2019, performed by a single surgical team, were assessed. Accuracy was evaluated by superimposing the postoperative computed tomography data with the preoperative virtual surgical plan. Predictors of the clinical outcomes affecting the accuracy were identified and analysed. The mean deviation and root mean square (RMS) estimate of the orbital, maxillary, and mandibular reconstructions were 0.88 ± 3.25 mm and 3.38 ± 0.73 mm, 0.77 ± 3.44 mm and 3.69 ± 0.82 mm, and 1.07 ± 4.16 mm and 4.67 ± 3.95 mm, respectively (P < 0.05). There was no significant difference in orbital volume or projection between the preoperative, postoperative, and healthy orbits (P = 0.093 and P = 0.225, respectively). Multivariate linear regression analysis confirmed significant associations between the accuracy of navigation-assisted mandibular reconstruction and preservation of the condyle, type of reconstruction, type of osteosynthesis plate, and number of bony segments. Navigation-assisted midface reconstruction yielded a higher level of accuracy in the final surgical outcome when compared to mandibular reconstruction. Computer-assisted techniques and intraoperative navigation can be an alternative or adjunct to current surgical techniques to improve the final surgical outcome, especially in more complex maxillofacial reconstructions.

Transcatheter cardiovascular interventions have the advantage of patient safety, reduced surgery time and minimal trauma to the patient's body. Transcathether interventions, which are performed percutaneously, are limited by the lack of direct line of sight with the procedural tools and the patient anatomy. Therefore, such interventional procedures rely heavily on image guidance for navigating toward and delivering therapy at the target site. Vascular navigation via the inferior vena cava, from the groin to the heart, is an imperative part of most transcatheter cardiovascular interventions including heart valve repair surgeries and ablation therapy. Traditionally, the inferior vena cava is navigated using fluoroscopic techniques such as venography and computed tomography venography. These X-ray-based techniques can have detrimental effects on the patient as well as the surgical team, causing increased radiation exposure, leading to risk of cancer, fetal defects and eye cataracts. The use of a heavy lead apron has also been reported to cause back pain and spine issues, thus leading to interventionalist's disc disease. We propose the use of a catheter-based ultrasound augmented with electromagnetic tracking technology to generate a vascular roadmap in real time and perform navigation without harmful radiation. In this pilot study, we used spatially tracked intracardiac echocardiography to reconstruct a vessel from a phantom in a 3-D virtual environment. We illustrate how the proposed ultrasound-based navigation will appear in a virtual environment, by navigating a tracked guidewire within the vessels in the phantom without any radiation-based imaging. The geometric accuracy is assessed using a computed tomography scan of the phantom, with a Dice coefficient of 0.79. The average distance between the surfaces of the two models comes out to be 1.7 ± 1.12 mm.

Accurate reconstruction of orbital and midfacial defects following extensive globe-sparing maxillectomy is challenging, due to the complex anatomy of facial skeleton. The aim of this study is to evaluate the outcomes of individually bent titanium mesh in navigation-assisted reconstruction of post-ablative orbits in comparison with that without intraoperative navigation. Forty-one patients undergone globe-sparing maxillectomy and orbital floor reconstruction using individually bent titanium mesh with or without intraoperative navigation were assessed. Pre- and postoperative orbital projection and volume measurements were performed on both orbits. The unaffected orbit was used as a control for comparison. True-to-original orbital reconstruction was achieved in this study. The average difference of globe projection and orbital volume between unaffected and reconstructed orbits was 0.8 ± 0.5 mm and 0.9 ± 1.2cm

The aim of this systematic review is to evaluate the accuracy of waferless osteotomy procedures in orthognathic surgery with a secondary aim to determine the cost-effectiveness of the procedure. A literature search was conducted on the databases PubMed and Scopus, with PRISMA guidelines followed. An initial yield of 4149 articles were identified, ten of which met the desired inclusion criteria. The total sample of patients undergoing waferless osteotomies included in this review was 142 patients. Nine of the studies used surgical cutting guides along with customised surgical plates to eliminate the surgical wafer and one study used pre-bent locking plates instead of customised plates. The eligible articles determined their surgical accuracy by comparing the positions of bony or dental landmarks on the pre-operative and post-operative images. The articles all reported acceptable accuracy within previously established clinical parameters. The majority of authors concluded that it is an accurate surgical approach and can be cost effective which is often a barrier to novel techniques however there were studies that contrasted the view of the cost efficacy. Due to the lack of published randomised controlled trials, current evidence is not strong enough to recommend the use of surgical cutting guides and customised/pre-bent plates for orthognathic surgery.

In studies that assessed the accuracy of implant surgical guides, evaluations were based on the placement position of the implant by using a manufactured surgical guide. However, such assessments could involve errors that may occur during implant placement. Therefore, evaluating the 3-dimensional accuracy of the fabrication of the implant surgical guide itself is not enough. In the evaluation method described in this article, location-related information is obtained by connecting a scan body to the sleeve of the surgical guide instead of directly placing the implant. This helps to evaluate the accuracy of the surgical guide without errors in the placement of an implant.

The use of surgical navigation has been shown to reduce revision rates after total knee arthroplasty (TKA) in patients65 years of age. It is unknown if this benefit extends to older patients. We hypothesized that the use of surgical navigation would reduce rates of all-cause revision in patients of all ages.In this cohort study, we queried the Truven MarketScan all-payer database to identify patients who underwent TKA from 2007 to 2015. Current Procedural Terminology codes were used to create 2 groups based on whether intraoperative navigation was used. Demographics, comorbidities, complications, and revision rates were determined. International Classification of Diseases codes were used to determine reasons for revision.The conventional TKA cohort included 312,173 patients. The navigation cohort included 20,881 patients. There were not any clinically significant differences in demographics between the cohorts. All-cause revision rates were lower in the navigation cohort at 1 year (0.4% vs 0.5%, P = .04), 2 years (0.7% vs 0.9%, P = .003), and 5 years (0.9% vs 1.3%, P.001) of follow-up. Revisions for mechanical loosening were more common in the conventional cohort (30.8% vs 21.9%, P = .009). Rates of revision for other causes, including infection, did not differ between groups, with the numbers available.The use of surgical navigation yielded a 30.7% reduction in the all-cause revision rate at 5-year follow-up compared to conventional TKA. This benefit increased as follow-up duration increased. Increased usage of this inexpensive technology, from the current 6.3% in this US cohort, may reduce healthcare costs.III.

The purpose of this systematic review was to critically analyze the recent literature to present the state of the art in customized reconstruction of orbital fractures. Three electronic databases and manual search approaches were used to identify relevant articles. Only studies with a controlled clinical study design were included. Primary outcome was defined as the status of recovery (complete/partial functional and esthetic disturbances). The benefit of intra-surgical navigation should be described. Secondary outcome was defined as the time of surgery, post-surgical events and hospitalization. A total of eight studies out of 552 records identified met the inclusion criteria. Post-surgical results in sense of recovery were shown to be superior in the customized group, and comparable to the control group in five studies. Time of surgery was shorter in the customized groups, as well as liquid infusion and time of hospitalization were reduced. Four studies documented a higher degree of accuracy in reconstruction by using navigation. All the studies presented at least one bias. A considerable heterogeneity of the studies was evaluated. This review documented, that in combination with navigated surgery, a higher accuracy in reconstruction could be obtained by using customized meshes. A significant reduction of surgery time was revealed.

The adequacy of the surgical resection is the main controllable variable that is in the hands of the surgical team. There exists an unmet need to increase the rate of negative margins, particularly in cancers invading the craniofacial area. The study aimed 1) at developing a gross tumor model to be utilized for research, educational, and training purposes and 2) establishing the 3-dimensional relationship between the outer surface of the surgical specimen and tumor surface and test the effect of guiding ablations on cadavers with surgical navigation (SN).Seven cadaver heads were employed to create 24 craniofacial tumor models. Simulation of tumor resections was performed by 8 surgeons. Fourteen and 10 resections were performed with and without SN-guidance, respectively. Gross specimens underwent computed tomography and 3-dimensional analysis through dedicated software. Task load was assessed through a validated questionnaire. Tumor model reliability was studied based on visual analogue scale rate by surgeons and radiologists.SN reduced the rate of margin involvement, particularly by decreasing the percentage of the gross specimen outer surface involvement in areas uncovered by normal bony structures. The workload of SN-aided ablations was found to be medium-to-somewhat-high. Tumor model reliability was deemed satisfactory except for the extension to bony structures.A gross tumor model for head and neck cancers involving the craniofacial area was developed and resulted satisfactorily reliable from both a surgical and radiologic standpoint. SN reduced the rate of margin involvement, particularly by improving delineation of bone-uncovered areas.

Stereotactic intraoperative computer-assisted navigation has been shown to improve pedicle screw accuracy in spinal fusion surgery, but evidence of impact of navigation on clinical outcomes is lacking. The aim of this study is to compare rates of perioperative complications between navigated and nonnavigated procedures for deformity correction.An administrative database was queried for adult patients undergoing thoracolumbar fusion procedures for deformity. Nonelective cases and those involving malignancy, infection, or trauma were excluded. Individuals were divided into 2 cohorts based on the use of stereotactic intraoperative navigation and paired 1:1 for comparison based on a propensity score matching algorithm. Rates of unplanned reoperation and other perioperative complications were compared between matched groups. A multivariable Cox regression model was constructed to identify the impact of navigation on specific subgroups.A total of 6150 patients met eligibility criteria for the study; after propensity score matching, 456 patients who underwent conventional fusion were matched to 456 patients receiving intraoperative navigation. Navigated cases took an average of 30 minutes longer than nonnavigated cases. There were no significant differences in rates of complications between cohorts. A subgroup analysis revealed that use of navigation was associated with decreased hazard for reoperation in individuals undergoing interbody fusion.Despite increased surgical duration, the use of navigation does not seem to significantly impact rates of perioperative complications outside of procedures involving interbody fusion. Surgeons should elect to use navigation in cases expected to be of high operative complexity at their own discretion.

We sought to evaluate the accuracy of using patient-specific drill guides to place bilateral laminar screws in C1 and C2.Nine cervical specimens (8 males; mean age: 66.6 [56-73]) with the occiput attached (C0-C3) were used in this study. Preoperative computed tomography (CT) scans were used to create digital anatomic models for templating and guide creation. A total of 36 screws were placed with the aid of 3-dimensional printed, patient-specific guides (2 screws at C1 and C2). Postoperative CT scans were performed following screw insertion. The planned and actual trajectories were compared using preoperative and postoperative imaging based on the angular and entry point deviation. After screw placement and postoperative imaging, each specimen was dissected and performed a visual inspection for breaches.No breaches or violations were observed on postprocedural CT and visual inspection. The average variation of the entry point in the X, Y, and Z axes was 0.3 ± 0.28, 0.41 ± 0.38, and 0.29 ± 0.24, respectively. No statistically significant difference (P0.05) was observed between the planned and obtained entry points. There was no significant difference (P0.05) in the deviation analysis between the planned and obtained angles in the axial and coronal planes.The study demonstrates that patient-specific drill guides allow for accurate C1 and C2 bilateral laminar screw placement, with a low risk of cortical breach.

Background In recent years, the development of digital imaging technology has had a significant influence in liver surgery. The ability to obtain a 3-dimensional (3D) visualization of the liver anatomy has provided surgery with virtual reality of simulation 3D computer models, 3D printing models and more recently holograms and augmented reality (when virtual reality knowledge is superimposed onto reality). In addition, the utilization of real-time fluorescent imaging techniques based on indocyanine green (ICG) uptake allows clinicians to precisely delineate the liver anatomy and/or tumors within the parenchyma, applying the knowledge obtained preoperatively through digital imaging. The combination of both has transformed the abstract thinking until now based on 2D imaging into a 3D preoperative conception (virtual reality), enhanced with real-time visualization of the fluorescent liver structures, effectively facilitating intraoperative navigated liver surgery (augmented reality). Data sources A literature search was performed from inception until January 2021 in MEDLINE (PubMed), Embase, Cochrane library and database for systematic reviews (CDSR), Google Scholar, and National Institute for Health and Clinical Excellence (NICE) databases. Results Fifty-one pertinent articles were retrieved and included. The different types of digital imaging technologies and the real-time navigated liver surgery were estimated and compared. Conclusions ICG fluorescent imaging techniques can contribute essentially to the real-time definition of liver segments; as a result, precise hepatic resection can be guided by the presence of fluorescence. Furthermore, 3D models can help essentially to further advancing of precision in hepatic surgery by permitting estimation of liver volume and functional liver remnant, delineation of resection lines along the liver segments and evaluation of tumor margins. In liver transplantation and especially in living donor liver transplantation (LDLT), 3D printed models of the donor's liver and models of the recipient's hilar anatomy can contribute further to improving the results. In particular, pediatric LDLT abdominal cavity models can help to manage the largest challenge of this procedure, namely large-for-size syndrome.

The aim of this study was to evaluate the safety and efficacy of using patient-specific polyetheretherketone (PEEK) for the reconstruction of patients with defects in orbital-maxillary-zygomatic (OMZ) complex.This study included 12 patients who underwent primary/delayed reconstruction of defects in OMZ complex by using patient-specific PEEK implants. Postoperative appearance (facial and orbital symmetry) and function were assessed after 6 months. Ophthalmologic examinations including globe position, exophthalmos, and orbital volume measurement were also performed. A comparative analysis of the treatment outcomes between pre- and postoperation was performed, and a value of P0.05 was considered as significant.All patients underwent planned surgical procedure successfully. No obvious complications occurred. Facial symmetry and globe position were improved after surgery and the postoperative esthetic assessment was rated as excellent. The postoperative evaluation revealed that exophthalmos was 15.91 ± 1.80 mm, vertical position difference of eyeball 15.91 ± 1.80 mm, and orbital volume 15.91 ± 1.80 mm, respectively. There was a statistically significant difference in the mean values of exophthalmos, vertical position difference, and orbital volume among pre- and postoperation conditions, whereas there was no statistically significant difference between the reconstructed side and the unaffected side after surgery.With the aid of virtual surgical planning and individual custom-made surgical guides, patient-specific PEEK implantation can successfully reconstruct the complicated 3D structure of OMZ complex and shows excellent biocompatibility and clinical outcomes.

Posterior parotid lithiasis may in some cases require a combined surgical approach associating sialendoscopy to an external intraoral or transfacial approach. This single-center retrospective study describes the surgical technique for parotid lithiasis extraction by a combined external and sialendoscopic approach with the help of CT-navigation. Five patients were included between November 2014 and July 2020. The sialolith was extracted in 100% of cases. Navigation and transillumination localizations matched consistently. No patients showed postoperative facial paresis. At 2 to 21 months’ follow-up, there was no recurrence of sialolithiasis. Navigation can be a complement to transillumination, improving surgical comfort and safety, but does not replace first-line sialendoscopy. Visual control is required whenever possible after extraction. In combined procedures, it enables accurate identification of parotid sialoliths. In case of impassable stenosis, it could be a therapeutic alternative to parotidectomy.

Summary Background Virtual Surgical Planning (VSP) is increasingly used in maxillomandibular osseous free flap reconstruction. Non-commercial (‘in-house') VSP may offer the same level of accuracy and other benefits, without the inflated costs and time delays inherent in using commercial providers. Comparisons between commercial and in-house methods are lacking. This study aims to determine the accuracy of VSP, comparing in-house and commercially planned cases, and to explore predictors of reconstruction error. Methods 76 patients who had a virtually planned maxillomandibular reconstruction between January 2012 and July 2020 were retrospectively identified. The pre-operative digital plan was compared to the post-operative CT scan in terms of: length of bone segments, angle between adjacent segments and intercondylar and intergonial angle distances (mandibular reconstructions only). Results 44 patients fulfilled the inclusion criteria. The mean intergonial and intercondylar distances error was 1.7 ± 1.01mm, mean segment length error was 1.3 ± 1.40mm, and mean angles error was 1.9 ± 2.32 degrees. The difference in error of in-house VSP compared to commercial VSP was not statistically significant for intercondylar and intergonial distance (p=0.76), segment length (p=0.15), or angle between segments (p=0.92). Increased error was associated with osteoradionecrosis as the indication for surgery, greater number of segments, and secondary reconstructions. Conclusion VSP is an accurate method of maxillary and mandibular reconstruction. In-house VSP may be similar in accuracy to commercial VSP options. Higher levels of inaccuracy are likely to occur in more complex reconstructions, particularly secondary reconstructions, and in the setting of osteoradionecrosis.

To evaluate radiation exposure and image quality (IQ) for 3 intraoperative imaging systems (Airo TruCT, Cios Spin, O-arm) using varying radiation dose settings in a single cadaveric model.Axial images of L4-5 instrumentation were obtained using 3 manufacturer dose protocols for each system. Measurements included scattered radiation dose, subjective and objective IQ, and estimates of patient effective dose (ED). Four images per system were selected at each dose level. Using the Likert scale (1 = best, 5 = worst), 9 reviewers rated the same 36 images. Objective IQ measures included the degree of streak artifacts (lines with incorrect data from metal objects) in each image. A composite figure of merit was derived based on ED and subjective and objective scores.The best subjective IQ scores were 1.44 (Cios Spin medium dose), 1.78 (Cios Spin high dose) and 2.22 (Airo TruCT low dose). The best objective IQ scores were 87.3 (Airo TruCT) and 89.1 (Cios Spin). ED low-dose results in mSv included 1.6 (Airo TruCT), 1.9 (Cios Spin), and 3.3 (O-arm). ED high-dose results in mSv included 4.6 (Cios Spin), 9.7 (Airo TruCT), and 9.9 (O-arm). Scatter radiation measurements for low dose in μGy included 21.9 (Cios Spin), 31.8 (Airo TruCT), and 33.9 (O-arm). Scatter radiation for high dose in μGy included 55.9 (Cios Spin), 104.5 (O-arm), and 200 (Airo TruCT). The best figure of merit score was for the Airo TruCT low dose, followed by Cios Spin medium dose and high dose.Selection of intraoperative imaging systems requires a greater understanding of the risks and benefits of radiation exposure and IQ.

Intraoperative computed tomography and navigation (iCT-Nav) is increasingly used to aid spinal instrumentation. We aimed to document the accuracy and revision rate of pedicle screw placement across many screws placed using iCT-Nav. We also assess patient-level factors predictive of high-grade pedicle breach.Medical records of patients who underwent iCT-Nav pedicle screw placement between 2015 and 2017 at a single center were retrospectively reviewed. Screw placement accuracy was individually assessed for each screw using the 2-mm incremental grading system for pedicle breach. Predictors of high-grade (2 mm) breach were identified using multiple logistic regression.In total, 1400 pedicle screws were placed in 208 patients undergoing cervicothoracic (29; 13.9%), thoracic (30; 14.4), thoracolumbar (19; 9.1%) and lumbar (130; 62.5%) surgeries. iCT-Nav afforded high-accuracy screw placement, with 1356 of 1400 screws (96.9%) being placed accurately. In total, 37 pedicle screws (2.64%) were revised intraoperatively during the index surgery across 31 patients, with no subsequent returns to the operating room because of screw malpositioning. After correcting for potential confounders, males were less likely to have a high-grade breach (odds ratio [OR] 0.21; 95% confidence interval [CI] 0.10-0.59, P = 0.003) whereas lateral (OR 6.21; 95% CI 2.47-15.52, P0.001) or anterior (OR 5.79; 95% CI2.11-15.88, P = 0.001) breach location were predictive of a high-grade breach.iCT-Nav with postinstrumentation intraoperative imaging is associated with a reduced need for costly postoperative return to the operating room for screw revision. In comparison with studies of navigation without iCT where 1.5%-1.7% of patients returned for a second surgery, we report 0 revision surgeries due to screw malpositioning.

A new individualized, cost-effective, modified semi-computer-assisted surgery (MSCAS) concept for free fibular flap mandibular reconstruction is reported and compared with the computer-assisted surgery (CAS) concept. Patients were divided into two groups and retrospectively reviewed. In the MSCAS and CAS groups, intraoperative guides were created using computer-aided design with manual fabrication and computer-aided design and manufacturing, respectively. Differences in specific linear and angular parameters on pre- and postoperative computed tomography scans were calculated for morphometric comparison, and clinical parameters and efficiency were analysed. RESULTS: Eighteen patients (CAS, 7; MSCAS, 11), were included. The morphometric comparison showed no significant differences between the groups. The mean deviation of the mandibular ramus length, body length, width 1 and width 2 was 0.82 ± 0.29 mm, 1.84 ± 0.43 mm, 1.89 ± 0.61 mm and 1.45 ± 0.61 mm in the CAS group versus 1.56 ± 0.54 mm, 1.72 ± 0.33 mm, 2.24 ± 0.55 mm and 2.36 ± 0.50 mm in the MSCAS group (p = 0.7804, p = 0.9997, p = 0.9814 and p = 0.6334). The mean deviation of the sagittal, axial and coronal mandibular angles was 1.56 ± 0.48°, 1.93 ± 0.50° and 2.15 ± 0.72° in the CAS group versus 2.19 ± 0.35°, 1.86 ± 0.35° and 1.94 ± 0.55° in the MSCAS group (p = 0.7594, p = 0.9996 and p = 0.9871). There were no significant differences in clinical parameters, efficiency or postoperative complications between the groups. CONCLUSION: The accuracy and operative efficiency of the MSCAS concept are comparable to those of the more expensive CAS concept. Therefore, in times of increasing clinical costs, this concept might be an adequate and inexpensive alternative to preoperative CAS.

Statement of problem An accurate surgical template for guided implant surgery is essential for the success of an implant restoration. However, reports on the accuracy of digitally designed and computer numeric controlled (CNC) machine-milled surgical templates are sparse. Purpose The purpose of this in vitro study was to investigate the accuracy of an implant surgical guide digitally designed by using data from cone beam computed tomography (CBCT) scans and milled with a 5-axis CNC machine. Material and methods Six representative radiographic templates were prepared from radiopaque resin plates. For each guide, a CBCT scan was made, and the extracted Digital Imaging and Communications in Medicine (DICOM) data were imported into a planning software program (ORGANICAL Dental Implant). Nine implants were virtually designed for each guide. The design data were imported into a 5-axis CNC machine, and the radiographic guides were fixed onto the CNC machine (Organical Multi S). Bore holes for surgical guide sleeves were milled directly in the radiographic template, which was converted into a surgical template. After the milling process, the surgical guides were scanned by using a laboratory cast scanner. The deviation between the position of the sleeve bore hole in the milled template and that in the virtual implant planning was digitally calculated. Results The mean global deviation of the surgical guide was 0.16 ±0.06 mm in the circle center of the sleeve top, and the mean angular deviation was 0.61 ±0.40 degrees. The sleeve-implant distance and the sleeve axis angle showed no significant influence on the in vitro accuracy of the implant surgical guide. Conclusions The mean deviation of the surgical guide prepared by using the virtual planning software and 5-axis CNC milling procedure in this study was 0.16 ±0.06 mm in the center of the sleeve top. Thus, the guide had acceptable precision.

To evaluate the use of radioactive iodine-125 seed (RIS) in breast and/or axillary surgery, in patients with breast cancer treated with neoadjuvant chemotherapy (NAC).Prospective study between January 2016 and June 2020. 80 women T1-3,N0-2,M0: 30 RIS marking the breast tumor, 36 both the tumor and the biopsied positive axillary node, and 14 only the axilla. Age: 54.7 ± 11.4 years. Tumor size: 34.1 ± 14.6 mm. Histological type: invasive ductal carcinoma 90.0%. Molecular subtypes: luminal-A 23.8%, luminal-B/HER2- 33.7%, luminal-B/HER2+ 18.8%, HER2+ 7.5%, basal-like 16,2%.Of the 66 patients with RIS marking of the tumor (51 pre-NAC, 15 post-NAC), 92.1% had tumor-free surgical margins, with a specimen volume of 126.7 ± 111.2 cmRIS allow to perform breast-conserving surgery and improve detection of residual axillary disease in patients treated with NAC.

The purpose of this study was to determine whether the use of custom osteosynthesis plates increased the accuracy of proximal segment position following bilateral sagittal split osteotomy in a cohort of 30 patients when compared to a control group of 25 patients who had surgery with conventional plates. Surgery was performed by a single surgeon between October 2015 and December 2017. Post-surgical cone beam computed tomography scans were segmented using Mimics Innovation Suite (Materialise NV), and surface-based superimposition was achieved using ProPlan CMF (Materialise NV). However, there was a tendency for the rotational error to be smaller in the custom group than in the control group. The root mean square error in both groups and for all variables fell within clinical parameters of 2 mm and 4°. In conclusion, the results of this study indicate that customized mandibular fixation plates do not necessarily improve the accuracy of the proximal segments post-surgically; however they may be of benefit in individual patients.

This systematic review aims to evaluate the possible time benefits when using three-dimensional planning prior to orthognathic surgery when compared to a conventional method only. The databases utilised were PubMed, MEDLINE, Web of Science and the Cochrane Library. Studies were selected based on eligibility criteria and reviewed independently by two authors. A total of 8 studies were included in the systematic review. The review concludes that there are limited studies with the appropriate experimental protocols in place. Therefore, although there is low-grade evidence to suggest three-dimensional planning in orthognathic surgery is more time efficient, the field would benefit from more rigorous studies being published.

Objective To evaluate factors contributing to positive surgical margins associated with reflector guidance for patients undergoing breast conserving therapy for malignancy. Materials and Methods A retrospective IRB-approved review of our institutional database was performed for malignant breast lesions preoperatively localized from January 1, 2018 to December 31, 2020. The following data was recorded using electronic medical records: lesion type and grade, lesion location, reflector and wire placement modality, use of intraoperative ultrasound, margin status, patient age, family history, BMI, and final pathology. Statistical analysis was performed with univariate summary statistics and logistic regression. P Results A total of 606 image-guided pre-surgical localizations were performed for lumpectomies of breast malignancies. A total of 352 of 606 (58%) wire localizations and 254 of 606 (42%) SCOUT reflector localizations were performed. Sixty out of 352 (17%) of wire-localized patients had positive surgical margins, whereas forty-eight out of 254 (19%) of reflector-localized patients had positive surgical margins. (OR = 1.12, P value: .59). For reflector guided cases, the use of intraoperative ultrasound (IOUS) was associated with decreased positive margin status (OR = 0 .28, 95% CI = [0.14, 0.58]) while in situ disease was associated with increased positive margin status (OR = 1.99, 95% CI = [1.05, 3.75]). No association between modality used for localization (mammography vs. ultrasound) and positive margin status was observed (OR = 0.63, 95% CI = [0.33, 1.19]). No association between positive margins and age, family history, tumor location and BMI was observed. Conclusion For reflector guided surgeries, the use of IOUS was associated with decreased positive margins, by contrast the presence of ductal carcinoma in situ was associated with increased positive margins. There was no statistically significant difference in surgical outcomes for reflector-guided localization compared to wire localizations of the breast.

A 12-year long, prospective, single center study was conducted, comparing two frameless systems for brain biopsies: ROSA robotic-assisted stereotaxy and BrainLab Varioguide image-guided stereotaxy (Image Guided Surgery, IGS).All consecutive adult and pediatric patients undergoing frameless brain biopsies were included. Successfully achieving diagnosis was the primary endpoint, analysis of all periprocedural complications was the secondary endpoint, and the tertiary endpoint was the length of the procedure, with the aim of assessing of the learning curve for each operator over time. The results for the ROSA robot and the Varioguide system were compared and benchmarked to data from the literature.We performed 526 on 516 patients, 314 with the ROSA robot (Group A) and 212 with the IGS Varioguide (Group B). Histological diagnosis was achieved in 97.4% of cases in Group A, versus 93.3% in Group B (p 0.05). No statistically significant difference was found for secondary and tertiary endpoints. The complication rate appeared similar between the 2 frameless systems, with a hemorrhagic complications rate of 3.5% in Group A and 4.7% in Group B. Permanent neurological deterioration was only recorded in 0.8% of cases from Group B. Mortality was recorded in 0.3% in Group A and 0.4% in Group B.This study provides evidence to confirm that robotic surgery lives up to its promises of increased safety, accuracy, and reliability.

Background To report the early outcomes of cone beam computed tomography (CBCT) using last generation 3D C-arm in patients undergone advanced endovascular aortic aneurysm repair (AdEVAR) and to identify risk factors that may predict any un-planned procedures. Methods Patients undergone AdEVAR between December 2017 and December 2018 were enrolled. Final CBCT was performed in all patients after digital subtraction angiography. Primary end points were the incidence of any positive findings and the following unplanned procedures intended as any endovascular manoeuvre performed to fix such technical defect. The secondary endpoints were comparison of outcomes between patients with positive findings undergone unplanned procedure (Group A) versus patients without findings (Group B). Results 132 patients underwent endovascular treatment for aortic aneurysm. Of these, 22 (33%) fenestrated-branched endovascular aneurysm repairs (F-BEVAR), 21 (29%) EVAR with iliac branch devices, 19 (26%) abdominal and 10 (14%) thoracic EVAR were included in the study. Unplanned procedures after CBCT were necessary in 22 patients (31%). Patients in both groups were similar excepted for BMI >25 kg/m2 (55% vs. 26%), hostile iliac anatomy (64% vs. 32%) and previous aortic treatment (73% vs. 32%) (P Conclusion The use of CBCT, especially in challenging scenarios, can reveal technical defects and may potentially limit the need for late reintervention. Patients undergone previous aortic surgery should be carefully evaluated and routine CBCT should be performed.

Background This study aimed to compare the external ventricular drain (EVD) placement accuracy and complication rates, between neuronavigation-guided, ultrasound-guided, and freehand techniques in our single-center cohort, and through an additional meta-analysis of the currently available literature. Methods A retrospective review of patients who underwent EVD insertion from January 2016 to April 2019 was conducted. Information regarding demographics, indication, Evans index, use of image guidance, accuracy of catheter tip placement, and procedural complications was extracted from electronic records and imaging systems. The accuracy of the EVD tip placement was classified according to the Kakarla grading system into optimal, or suboptimal based on its proximity to the Foramen of Monro and involvement of noneloquent/eloquent structures. Results In total, 294 patients (median age of 54 years) underwent EVD insertion during the study period. A total of 183 catheters were placed freehand, 66 neuronavigation-guided, and 45 ultrasound-guided; the mean Evans ratios were 0.33, 0.29, and 0.31, respectively. Whilst there was a tendency for lower rates of suboptimal placement were guidance was used, with rates of 10.6% and 15.6% for neuronavigation- and ultrasound-guidance, respectively, compared to 20.8% in freehand placement, this did not reach statistical significance (P = 0.168). However, pooling this data with two additional studies on meta-analysis found a significant reduction in the risk of suboptimal placement for image-guided vs. freehand EVDs (odds ratio: 0.50, 95% CI: 0.32–0.77, P = 0.002). Surgeon seniority and other procedure-related factors had no significant impact on EVD placement accuracy or complications. Conclusions Our results, pooled with those of previous studies, suggest image-guided EVD placement significantly reduced the rate of suboptimally placed EVDs. We conclude in appropriately selected cases that image-guided EVD insertions may improve accuracy of catheter placements and reduce associated complications of the procedure.

Craniofacial reconstruction represents a major challenge due to the complex anatomical morphology. Although implant production has often been outsourced to external companies, in-house planning and manufacturing has developed in many centres. This note introduces a conceptualized modular mould system to perform any desired craniofacial reconstruction, named ‘Cubik’, inspired by the famous Rubik’s cube. A sophisticated virtual process is described that simulates realistic cranio-orbital resections, and the workflow to create multi-component moulds in order to achieve intraoperatively moulded implants is presented. The description focuses on the appropriate definition of interfaces between the subdivision surfaces of the planned implant, which is the key element to successful design and function of the moulds during surgery and is the peculiarity of the Cubik system. The use of Cubik does not prolong the overall duration of surgery, and it appears to be a very versatile tool, allowing personalized implants with different morphology to be created, which are suitable to cover every potential defect of the skull and the orbital region. This study extends the potential of in-house production, allowing highly accurate implantable craniofacial implants to be fabricated, and in the future this might represent a solution to achieve in-house replacement of other segments of the facial skeleton.

In the present study, we tried to review the current literature, focusing on the effect of different guide systems on the accuracy of the digital surgical guides. A search in PubMed’s database, without any date restriction, was performed using keywords based on the PICO question. 54 of the 2378 articles’ were chosen for full-text assessment. Articles were screened using predetermined inclusion and exclusion criteria. 21 articles were included in the qualitative assessment. Descriptive analysis was performed for numeric parameters using mean ± standard deviation. Six types of guide systems were used in the included articles. The commonest guide system was SimPlant (45.64%) followed by NobleGuide (23.00%). The pooled mean angle deviation, global coronal deviation, and global apical deviation were 3.43 mm (95% CI = 2.96, 3.90), 1.16 mm (95% CI = 0.98, 1.24) and 1.35 mm (95% CI = 1.11, 1.59), respectively. The maximum mean(SD) of angle deviation, global coronal deviation, and global apical deviation happened in Stent Cad 4.1(1.86) degrees, NobleGuide 1.86(0.56) mm, and OnDemend3d 1.56(1.48) mm, respectively. Although a final statement could not be made on which system is better, it is certain that the software affects the deviation and could be as important as the implant itself. Clinical significance The choice of guide systems used for the production of static guide systems which was studied in this article could affect the accuracy of the implant placement procedure.

International audience; OBJECTIVES: Patients waking up with stroke symptoms are often excluded from intravenous thrombolysis with alteplase (IV-tpa). The WAKE-UP trial, a European multicenter randomized controlled trial, proved the clinical effectiveness of magnetic resonance imaging-guided IV-tpa for these patients. This analysis aimed to assess the cost-effectiveness of the intervention compared to placebo. METHODS: A Markov model was designed to analyze the cost-effectiveness over a 25-year time horizon. The model consisted of an inpatient acute care phase and a rest-of-life phase. Health states were defined by the modified Rankin Scale (mRS). Initial transition probabilities to mRS scores were based on WAKE-UP data and health state utilities on literature search. Costs were based on data from the University Medical Center Hamburg-Eppendorf, literature, and expert opinion. Incremental costs and effects over the patients' lifetime were estimated. The analysis was conducted from a formal German healthcare perspective. Univariate and probabilistic sensitivity analyses were performed. RESULTS: Treatment with IV-tpa resulted in cost savings of €51 009 and 1.30 incremental gains in quality-adjusted life-years at a 5% discount rate. Univariate sensitivity analysis revealed incremental cost-effectiveness ratio being sensitive to the relative risk of favorable outcome on mRS for placebo patients after stroke, the costs of long-term care for patients with mRS 4, and patient age at initial stroke event. In all cases, IV-tpa remained cost-effective. Probabilistic sensitivity analysis proved IV-tpa cost-effective in \textgreater95% of the simulations results. CONCLUSIONS: Magnetic resonance imaging-guided IV-tpa compared to placebo is cost-effective in patients with ischemic stroke with unknown time of onset.

The medical application of 3-dimensional printing technology has evolved in the last decade, with an increasing variety of uses in hand surgery. The ability for patient-specific design, rapid prototyping, and low cost of production of 3-dimensional printed materials has led to this rise in clinical applications, both for common procedures and complex reconstructions. Within hand surgery, 3-dimensional printing can be applied in several broad categories: to construct patient-specific models for preoperative planning, to design orthotics and prosthetics to meet specific patient demands, to create patient-specific aids for intraoperative use, to generate patient-specific hardware and prostheses for implantation, and for applications for trainee education.

Purpose This systematic review and meta-analysis aims to investigate the influence of dynamic navigation systems on accuracy (platform, apical and angular deviations) in clinical studies. Methods The research question was “Do dynamic navigation systems enhance the accuracy of implant placement?” The PubMed, Scopus and Embase databases were used to search the relevant studies up to January 2021. The role of dynamic navigation systems in enhancing the accuracy (platform, apical and angular deviations) of implant placement was then analyzed to conduct a systematic review and meta-analysis. Results Eight articles were analyzed in the systematic review and meta-analysis. The systematic review showed that the deviations in implant placement were significantly lower for dynamic navigation than for the freehand method, and there were no significant differences between the dynamic navigation and static guide methods. This meta-analysis showed that the dynamic navigation group exhibited less platform deviation, apical deviation and angular deviation than the control group. The results of subgroup analyses showed that the dynamic navigation group exhibited fewer deviations than the freehand group, and no significant differences were found between the dynamic navigation and static guide groups. Conclusions Dynamic navigation resulted in higher accuracy than the freehand method, and similar accuracies were found between dynamic navigation and static guidance for platform deviation, apical deviation or angular deviations.

Imageless computer navigation improves component placement accuracy in total hip arthroplasty (THA), but variations in the registration process are known to impact final accuracy measurements. We sought to evaluate the registration accuracy of an imageless navigation device during THA performed in the lateral decubitus position.A prospective, observational study of 94 patients undergoing a primary THA with imageless navigation assistance was conducted. Patient position was registered using 4 planes of reference: the patient's coronal plane (standard method), the long axis of the surgical table (longitudinal plane), the lumbosacral spine (lumbosacral plane), and the plane intersecting the greater trochanter and glenoid fossa (hip-shoulder plane). Navigation measurements of cup position for each plane were compared to measurements from postoperative radiographs.Mean inclination from radiographs (41.5° ± 5.6°) did not differ significantly from inclination using the coronal plane (40.9° ± 3.9°, P = .39), the hip-shoulder plane (42.4° ± 4.7°, P = .26), or the longitudinal plane (41.2° ± 4.3°, P = .66). Inclination measured using the lumbosacral plane (45.8° ± 4.3°) differed significantly from radiographic measurements (P.0001). Anteversion measured from radiographs (mean: 26.1° ± 5.4°) did not differ significantly from the hip-shoulder plane (26.6° ± 5.2°, P = .50). All other planes differed significantly from radiographs: coronal (22.6° ± 6.8°, P = .001), lumbosacral (32.5° ± 6.4°, P.0001), and longitudinal (23.7° ± 5.2°, P.0001).Patient registration using any plane approximating the long axis of the body provided a frame of reference that accurately measured intraoperative cup position. Registration using a plane approximating the hip-shoulder axis, however, provided the most accurate and consistent measurement of acetabular component position.

Background The objective of this study is to provide the 5-year follow-up results of a randomized study comparing conventional versus electromagnetic computer navigated total knee arthroplasty. Methods Analysis of 127 patients (66 navigated and 61 conventional surgeries) was performed from a prospective, single-blinded, randomized controlled trial. Patient-reported outcome measures were collected at 5 years after surgery and compared with previously published 1-year clinical outcomes. Five-year surgical revision rates were collated and compared between intervention groups. Results Overall, there have been continued improvements in the clinical scores of patients in both groups when compared with clinical data at 1 year; however, at 5 years, there is no statistical difference in any of the patient-reported outcome measures between conventional and navigated surgery. Interestingly, improved implant survivorship was observed in the navigated (0% revision rate) compared with the conventional group (4.9% all-cause revision rate). Conclusion Electromagnetic computer navigated technology produces similar clinical outcomes compared with traditional surgery. Further work is required to monitor implant survivorship, and clinical outcomes with long-term follow-up, to determine the cost effectiveness of this technology.