Use Of Intraoperative Navigation Research Articles

High accuracy of positioning custom triflange acetabular components in tumour and total hip arthroplasty revision surgery.

Custom triflange acetabular components (CTACs) play an important role in reconstructive orthopaedic surgery, particularly in revision total hip arthroplasty (rTHA) and pelvic tumour resection procedures. Accurate CTAC positioning is essential to successful surgical outcomes. While prior studies have explored CTAC positioning in rTHA, research focusing on tumour cases and implant flange positioning precision remains limited. Additionally, the impact of intraoperative navigation on positioning accuracy warrants further investigation. This study assesses CTAC positioning accuracy in tumour resection and rTHA cases, focusing on the differences between preoperative planning and postoperative implant positions. A multicentre observational cohort study in Australia between February 2017 and March 2021 included consecutive patients undergoing acetabular reconstruction with CTACs in rTHA (Paprosky 3A/3B defects) or tumour resection (including Enneking P2 peri-acetabular area). Of 103 eligible patients (104 hips), 34 patients (35 hips) were analyzed. CTAC positioning was generally accurate, with minor deviations in cup inclination (mean 2.7°; SD 2.84°), anteversion (mean 3.6°; SD 5.04°), and rotation (mean 2.1°; SD 2.47°). Deviation of the hip centre of rotation (COR) showed a mean vector length of 5.9 mm (SD 7.24). Flange positions showed small deviations, with the ischial flange exhibiting the largest deviation (mean vector length of 7.0 mm; SD 8.65). Overall, 83% of the implants were accurately positioned, with 17% exceeding malpositioning thresholds. CTACs used in tumour resections exhibited higher positioning accuracy than rTHA cases, with significant differences in inclination (1.5° for tumour vs 3.4° for rTHA) and rotation (1.3° for tumour vs 2.4° for rTHA). The use of intraoperative navigation appeared to enhance positioning accuracy, but this did not reach statistical significance. This study demonstrates favourable CTAC positioning accuracy, with potential for improved accuracy through intraoperative navigation. Further research is needed to understand the implications of positioning accuracy on implant performance and long-term survival.

Planned Glenoid Implant Utilization: A Comparison of Preoperative Planning with and Without Computer-Assisted Navigation.

Preoperative planning for anatomic total shoulder arthroplasty (aTSA) and reverse total shoulder arthroplasty (rTSA) is becoming increasingly common. While preoperative planning allows surgeons to determine individualized implant types, utilization of intraoperative navigation improves the accuracy of implant placement and may increase confidence in the preoperative plan. The purpose of this study was to evaluate and compare the rate at which surgeons use a glenoid implant different than their preoperative plan with and without the use of computer navigation. A retrospective review of a multicenter prospectively collected shoulder arthroplasty database was conducted between 2016 and 2022. Inclusion criteria were primary aTSA or rTSA with an available preoperative plan and record of the actual implant used. Change in glenoid implant was defined as a deviation in the final implant from the preoperative plan in regard to backside shape (nonaugmented vs augment or differing augment shape). We included 1,915 shoulder arthroplasties (525 aTSA, 1,390 rTSA) performed with preoperative planning and intraoperative navigation and 110 shoulder athroplasties (37 aTSA, 73 rTSA) performed with preoperative planning alone. Overall, the final glenoid implant deviated from the preoperative plan less frequently when intraoperative navigation was used compared with preoperative planning alone (1.9% [n = 36] versus 7.3% [n = 8], P = 0.002). When stratified by procedure, deviation from the preoperative plan occurred significantly less for rTSA when preoperative planning was used with intraoperative navigation versus planning alone (2% [n = 29] versus 11% [n = 8], P < 0.001; OR = 0.17 [95% CI = 0.07 to 0.46]), but not aTSA (1% [n = 7] versus 0% [n = 0], P = 1). Use of intraoperative navigation was independently associated with lower odds of deviation from the preoperative plan on multivariable logistic regression (OR = 0.25 [95% CI = 0.11 to 0.56], P = 0.001). Use of intraoperative navigation is associated with increased adherence to the preoperative plan for primary rTSA. Use of navigation may increase surgeon confidence despite known limitations of glenoid visualization during this procedure. This may offer advantages in outpatient surgery centers and smaller hospitals where inventory space may be limited. Ⅲ, retrospective cohort study.

Fluoro HIP, a new software for intraoperative evaluation of the cup angles based on fluoroscopic images

PurposeDespite its clinical benefits, intraoperative navigation is currently used only in approximately 20% of total hip arthroplasties (THA) partly due to the high cost of the systems and time-consuming preoperative preparation. By providing a simpler and less expensive alternative, the use of intraoperative navigation is likely to increase among surgeons. In this study, we sought to validate the accuracy and utility of Fluoro HIP, a newly developed cup angle measurement software that runs on iOS devices. MethodsTwenty-seven patients who underwent primary total hip arthroplasty between June and September 2022 were included in the study. All patients underwent surgery in the supine position. Inclination and anteversion angles were determined using Fluoro HIP software based on the fluoroscopic images captured during surgery. Navigation errors were calculated by comparing with the values obtained from postoperative CT images. ResultsThe inclination and anteversion angles measured were 38.7 ​± ​3.9 and 15.0 ​± ​3.1°, respectively. The absolute value errors were 2.7 ​± ​1.9 and 3.0 ​± ​2.1° for the inclination and anteversion, respectively. Although Fluoro HIP software-based system may not be as precise as the conventional CT-based or portable navigation systems, the intraoperative evaluation of the cup angles by this system was considered to have acceptable accuracy and reproducibility for most THA cases performed in the supine position. Most importantly, our system requires no preoperative preparation and is significantly less expensive than other types of navigation systems currently in use. ConclusionThe Fluoro HIP software-based system is a highly cost-effective and affordable alternative to the conventional navigation systems.

Mid-term Results Following Reverse Shoulder Arthroplasty and the Role of Navigation in the Management of Glenoid Bone Loss.

Background Inaccurate positioning of the glenoid component has been well described as the most common cause of early failure following a reverse shoulder arthroplasty (RSA). Among the latest developments in operative technique, three-dimensional preoperative planning and navigation intraoperative systems have been developed to improve the accuracy of the baseplate positioning during RSA. The primary purpose of this retrospective analysis was to investigate the mid-term results of patients who underwent an elective RSA or for acute highly comminuted proximal humerus fractures. The secondary goal was to investigate the role of navigation in the execution of preoperative planning, especially in the management of glenoid bone loss. Methodology In total, 101 cases were included in this study. Patients were divided into the following two groups: 88 cases of RSA performed without the use of navigation (conventional RSA) and 13 cases performed using intraoperative navigation (navigated RSA). For all patients included in the study, preoperative planning software was employed. Patient demographics, gender, past medical history, indication of procedure, operated site, type of glenoid component used, length of baseplate screws, and clinical assessment scores (Oxford Shoulder Score, OSS) were reported for all patients. Cases of revision shoulder arthroplasty were excluded from this study. Results The postoperative clinical assessment of patients revealed that following RSA, all patients improved significantly with a consistently upward trend of the OSS noted for both groups (conventional and navigated RSA) throughout the postoperative assessment. Despite no statistically significant difference detected, the clinical scores of the navigated RSA group outperformed those of the conventional RSA group in the postoperative period. A higher incidence of augmented baseplate use was noted in the navigated RSA group than in the conventional group (23.07% vs. 5.68%, p < 0.001). Conclusions Our results indicate that the use of intraoperative navigation appears to be a valuable tool in preoperative planning, providing accurate positioning of the baseplate, a better understanding of the glenoid anatomy, and real-time monitoring of the length and direction of the baseplate screws. It is difficult to conclude if the use of navigation leads to superior clinical outcomes, and the cost-effectiveness of its use needs to be further analyzed. Prospective randomized trials are required to assess the cost-effectiveness of routine use of navigation in RSA.

Surgical Navigation Applied in Removal of Glass Located Under Zygomatic Arch.

The limited detection rate of plain radiography (as low as 75%) for glass particles within the softs renders the conventional C-arm visualization method ineffective in intraoperative scenarios. The authors report the successful use of intraoperative navigation to visualize and extract multiple small glass fragments located deep within the temporal fossa and beneath the zygomatic arch. A 25-year-old man presented with a deep facial laceration, suspected injury to the temporal branch of the facial nerve, and a 2×2cm foreign body beneath the sphenoid bone near the left zygomatic arch. The initial surgery removed most of the glass; however, two 4mm fragments remained near the skull base. Using intraoperative navigation, a 3cm incision was made, and a navigating stylet was used to locate and remove the foreign bodies. In conclusion, intraoperative navigation is a precise method for removing small, imperceptible glass fragments from challenging anatomic areas, thus reducing the need for extensive dissection compared to conventional approaches.

EVALUATION OF CLINICAL OUTCOMES AND ACCURACY IN TRANSPEDICULAR SCREW FIXATION USING INTRAOPERATIVE CT-GUIDED NAVIGATION FOR LUMBAR SPONDYLOLISTHESIS

The use of intraoperative navigation and robotic surgery for minimally invasive lumbar fusion has been increasing over the past decade. The aim of this study is to evaluate postoperative clinical outcomes, intraoperative parameters, and accuracy of pedicle screw insertion guided by intraoperative navigation in patients undergoing lumbar interbody fusion for spondylolisthesis. Patients who underwent posterior lumbar fusion interbody using intraoperative 3D navigation since December 2021 were included. Visual Analogue Scale (VAS), Oswestry Disability Index (ODI), and Short Form Health Survey-36 (SF-36) were assessed preoperatively and postoperatively at 1, 3, and 6 months. Screw placement accuracy, measured by Gertzbein and Robbins classification, and facet joint infringement, measured by Yson classification, were assessed by intraoperative Cone Beam CT scans performed at the end of instrumentation. Finally, operation time, intraoperative blood loss, hospital stay, and screw insertion time were evaluated. This study involved 50 patients with a mean age of 63.7 years. VAS decreased from 65.8±23 to 20±22 (p&lt;.01). ODI decreased from 35.4%±15 to 11.8%±14 (p&lt;.01). An increase of SF-36 from 51.5±14 to 76±13 (p&lt;.01) was demonstrated. The accuracy of “perfect” and “clinically acceptable” pedicle screw fixation was 89.5% and 98.4%, respectively. Regarding facet violation, 96.8% of the screws were at grade 0. Finally, the average screw insertion time was 4.3±2 min, hospital stay was 4.2±0.8 days, operation time was 205±53 min, and blood loss was 169±107 ml. Finally, a statistically significant correlation of operation time with hospital stay, blood loss and placement time per screw was found. We demonstrated excellent results for accuracy of pedicle screw fixation and violation of facet joints. VAS, ODI and SF-36 showed statistically significant improvements from the control at one month after surgery.Navigation with intraoperative 3D images represents an effective system to improve operative performance in the surgical treatment of spondylolisthesis.

Approaches to the Middle Cerebellar Peduncle for Resection of Pontine Cavernomas.

The expanded retrosigmoid approach with splitting of the horizontal cerebellar fissure provides a more direct and shorter route for central and dorsolateral pontine lesions while minimizing retraction of tracts, nuclei, and cerebellum. 1-4. The middle cerebellar peduncle is partially covered by the petrosal surface of the cerebellum. The horizontal cerebellar fissure (petrosal fissure) divides the petrosal surface of the cerebellar hemisphere into superior and inferior parts. Splitting the petrosal fissure separates the superior and inferior petrosal surfaces and exposes the posterolateral middle cerebellar peduncle (posterior and lateral to the root entry zone of CN5). 1-4. Expanded retrosigmoid craniotomy is performed, including unroofing of the sigmoid sinus; petrosal fissure is split to expose the posterolateral middle cerebellar peduncle; entry point for resection of the cavernoma is identified; nims stimulator stimulator is used to confirm the absence of tracts and nuclei; myelotomy is performed; and cavernoma and its draining vein (but not the developmental venous anomaly) are removed using a combination of traction and countertraction against gliotic plane. Wide splitting of the horizontal cerebellar fissure minimizes retraction or resection of the cerebellum and offers the best angle of attack. Knowledge of brainstem anatomy and use of intraoperative navigation are critical to avoid complications. Far lateral through the middle cerebellar peduncle is a variant that can be used to resect pontine cavernomas if a caudocranial trajectory is preferred.The patient consented to the procedure and to the publication of her image.

Intraoperative Radiation Exposure in Adolescent Idiopathic and Neuromuscular Scoliosis.

Intraoperative imaging is often used to aid pedicle screw placement during scoliosis operations. Higher rates of cancer and death have been observed in orthopaedic surgeons and radiation technologists, including a fourfold higher rate of breast cancer in female orthopaedic surgeons. The purpose of this study was to evaluate variability in intraoperative radiation during spinal fusions for both adolescent idiopathic scoliosis (AIS) and neuromuscular scoliosis (NMS). A retrospective review of posterior spinal fusion and segmental spinal instrumentation for scoliosis performed by pediatric orthopaedic surgeons from 2017 to 2019 at a single institution was performed. Inclusion criteria included: a diagnosis of AIS or NMS and patients between 8 and 18 years of age. Exclusion criteria included: revision surgery, use of intraoperative navigation, and patients younger than 10 at the time of scoliosis onset within the AIS cohort. Data collected included: preoperative curve, body mass index (BMI), number of levels fused, number of Ponte osteotomies, and fluoroscopy time. One-way analysis of variance tests, Bonferroni post hoc tests, independent t tests, and Pearson correlations were utilized with significance determined at the 95% confidence level (a = 0.05). A total of 148 patients were included in the study. The average fluoroscopy time was 143 ± 67 seconds. Patients with NMS had higher average fluoroscopy times (193 ± 75 s) compared with patients with AIS (129 ± 58 s, P < 0.001). In patients with AIS, fluoroscopy time correlated to the patient's preoperative curve (r = 0.182, P = 0.050). Patients with AIS with fewer than 12 levels fused had significantly less radiation exposure than those with 12 or more levels fused (P = 0.01). When controlling for the number of levels fused, patients with AIS with higher BMIs had significantly greater fluoroscopy times (P = 0.001). In patients with NMS, fluoroscopy time negatively correlated with BMI (r = -0.459, P = 0.009) and positively correlated with a preoperative curve (r = 0.475, P = 0.007). Fluoroscopy times vary greatly during adolescent spinal fusions for scoliosis. Longer fluoroscopy times are correlated with: NMS diagnosis, larger preoperative curve, BMI, and number of levels fused. Surgeons' knowledge of factors affecting fluoroscopy time will increase awareness and may be the first step in decreasing intraoperative radiation risks. Level III; Therapeutic-a retrospective study.

Applications of navigation in full-endoscopic spine surgery.

Advancement in all surgery continues to progress towards more minimally invasive surgical (MIS) approaches. One of the platform technologies which has helped drive this trend within spine surgery is the development of endoscopy; however, the limited anatomic view experienced when performing endoscopic spine surgery requires a significant learning curve. The use of intraoperative navigation has been adapted for endoscopic spine surgery, as this provides computer-reconstructed visual data presented in three dimensions, which can increase feasibility of this technique to more surgeons. This paper will describe the principles, technical considerations, and applications of stereotactic navigation-guided endoscopic spine surgery. Full-endoscopic spine surgery has advanced in recent years such that it can be utilized in both decompressive and fusion surgeries. One of the major pitfalls to any minimally invasive surgery (including endoscopic) is that the limited surgical view can often complicate the surgery or confuse the surgeon, leading to longer operative times, higher risks, among others. This is the real utility to using navigation in conjunction with the endoscope-when registered correctly and utilized appropriately, navigated endoscopic spine surgery can take some of the guesswork out of the minimally invasive approach. Using navigation with endoscopy in spine surgery can potentially expand this technique to surgeons who have yet to master endoscopy as the assistance provided by the navigation can alleviate some of the complexities with anatomic understanding and surgical planning.

Surgical management of lumbosacral and sacral fractures: roles of the pelvic and spinal surgeons.

In young patients, lumbosacral fractures result primarily from high-energy traumas. Life-threatening lesions (e.g. visceral organs) are frequently associated with these fractures. Management consists of medical intensive care for adequate resuscitation and specialized surgical input. Lumbosacral junction represents a frontier between the spine and pelvic ring. Any injury in this area implies a thorough examination of both spine and pelvis through clinical examinations and CT scans. Patients must be assessed specifically for neurological and bladder/bowel symptoms. Several surgical classifications may be required to describe the entire fracture pattern. In unstable fracture with large displacements, definitive surgical fixation is often recommended. Various pelvic and spine surgery techniques can be used depending on the fracture pattern, surgeon's experience, and available equipment. The use of intraoperative navigation may enhance placement of instrumentation, especially in cases of complex fractures, percutaneous fixations, and/or atypical patients' anatomy. The fracture itself can cause debilitating complications with long-term consequences such as pain, neurological deficits, and bladder/bowel impairments. Wound infection remains the most common postoperative complication and prominent posterior instrumentation is frequently a source of pain. Irrespective of the treatment, leg discrepancy can be problematic in the case of malunion. Management of lumbosacral fractures requires a thorough understanding of both lumbar spine and pelvic injuries. Surgical treatment may involve a combination of spine and pelvic surgery techniques. Therefore, this implies for the surgeon to be trained specifically for these fractures, or else a close cooperation between the pelvic surgeon and the spine surgeon in managing the patients.

Craniocervical fusion in the paediatric population – case series of 21 patients

Purpose Craniocervical junction instability in a paediatric population presents a formidable challenge to the neurosurgeon. With a variety of anatomical variations, diminutive bony and ligamentous structures, possible superimposed syndromic abnormalities, the craniocervical junction is a technically challenging region to operate within. We aimed to review our series of patients to identify the common pathologies necessitating craniocervical fusion along with the use of intraoperative image guidance. Methods We performed a retrospective review of twenty-one patients, with a mean age of 8.1 years, undergoing craniocervical fixations, involving either occipitocervical fusion or atlantoaxial fixation, from a single institution over a twelve-year period. The presentation, preoperative investigations, indication for surgery, surgical procedure, use of intraoperative navigation and clinical and radiological results were examined. Results Twelve patients underwent primary C1–2 fixation, with the remaining 9 undergoing occipitocervical fusion. Five patients underwent surgery for traumatic instability, seven for os odontoideum, six for congenital anomalies and three for post-infectious instability. Follow up for 20 patients averaged 34 months (range 2–93 months). Five patients had Trisomy 21 and all underwent C1–2 fixation. Frameless stereotactic image guidance was utilised in five patients. No patients suffered immediate complications resulting from craniocervical junction fusion. Patients were observed to either neurologically improve (n = 6), or arrest their neurological deterioration following surgical intervention (n = 14), with concomitant radiological evidence of osseous fusion at follow up in 18 of 20 patients (90%). Two patients (10%) had radiological evidence of screw lucency, but neither required intervention because of being asymptomatic. Conclusions Craniocervical fixation in a paediatric population is a viable and safe treatment modality for the management of disorders requiring stabilisation at the craniocervical junction. Our experience of utilising frameless stereotaxy in the setting of grossly distorted anatomical landmarks is also reported.

Применение интраоперационной навигации в эндоскопической эндоназальной хирургии мукоцеле околоносовых пазух

Objective. Evaluation of the effectiveness, safety, and benefit of the use of electromagnetic computer navigation in endoscopic endonasal surgery of paranasal mucocele. Materials and methods. At the Burdenko National Medical Research Center, from 2019 to 2022, 30 endoscopic endonasal removal of paranasal mucocele were performed: 10 operations were performed under CT-guided navigation, 12 with CT-MRI navigation, and 8 without navigation. The clinical findings of the disease, the history of life of patients, the data of endoscopic examination of the nasal cavity, olfactometry, intraoperative parameters, recurrence rate of the mucocele were analyzed. Results. Localization of the mucocele in the frontal sinus was significantly more common in the groups using navigation (p = 0.044). According to olfactometry before surgery, anosmia on the side of the pathology was more often detected in patients in groups using navigation (p = 0.005). According to endoscopy before surgery, scarring in the nasal cavity was found only in groups using navigation. There were no intraoperative complications in the three groups. The average intraoperative blood loss in the three groups did not differ significantly. The duration of the operation was slightly longer in the groups using navigation. The median navigation setup time in the CT navigation group was 8.5 [7.3; 9.8] min, in the CT-MRI navigation group it was 7.5 [7.0; 8.3] min. The median error in each group was 0 mm. According to the operating surgeon, computer navigation was necessary and the most beneficial in 100% of cases. The median long-term follow-up was 746 [478.3; 1133.0] days in the non-navigation group, 673 [176.0; 791.0] days in the CT-navigation group, and 274 [195.5; 371.0] days in the CT-MRI navigation group. Conclusion. The use of intraoperative navigation is justified in endoscopic debridement of mucocele with destruction of the walls of the orbit and the base of the skull, with scarring in the nasal cavity. The use of CT-MRI navigation is useful in a case of scarring in the nasal cavity and deformation of the orbit walls in the case of a fronto-orbital mucocele as well as while removing a sinonasal neoplasm bordering on the mucocele.

Outcomes and Complications of Pelvic Chondrosarcomas Treated Using Navigation Guidance and Multidisciplinary Approach: Is the Tumor Volume a Prognostic Factor?

(1) Background: Pelvic Chondrosarcomas (CS) have a poor prognosis. The grade is the most important survival predictor; other factors are periacetabular location and Dedifferentiated CS subtype. The aim of the study is to investigate a series of CS of the pelvis, to analyze the prognostic factors that affect outcomes and to demonstrate how the use of intraoperative navigation can reduce the complications without worse outcomes. (2) Methods: Retrospective study on 35 patients (21 M, 14 F), median age at surgery 54 years (IQR 41−65), with pelvic CS, treated with hemipelvectomy under navigation guidance. (3) Results: 30 high-grade CS and 5 low-grade CS; mean follow-up 51.4 months. There was a positive linear correlation between the tumor volume and the presence of local recurrence at follow-up. The mean survival time of patients with larger chondrosarcoma volume was lower, but not significantly so. Lower MSTS score was associated with significantly lower survival time (p < 0.001). (4) Conclusion: in this series overall survival, LR and distant metastasis were comparable with recent literature, while complication rate was lower compared to similar series without the use of navigation. There was a correlation between tumor volume and local recurrence rate but not with the presence of metastasis at follow up.

P-67915014-268 - Does intra-operative navigation improve accuracy of implant position in secondary reconstruction of large orbital defects?

<h3>Background and Purpose</h3> Literature supporting use of intra-operative navigation (ION) in orbital reconstruction is abundant. However, evidence on the role of ION in improving orbital implant position is sparse. Our objective was to determine if ION influenced implant position accuracy in secondary orbital reconstruction. <h3>Methods</h3> This was designed as a prospective observational study comparing two groups of patients requiring secondary orbital reconstruction; the test group received intra-operative guidance with ION, while the control did not. The groups were matched for age and defect size. Primary outcome variables included assessment of deviations between the ideal implant position and achieved implant position in six degrees of freedom; horizontal, vertical and transverse (linear), pitch, roll and yaw (angular). Secondary outcome variables included assessment of procedural time. Descriptive and inferential statistics were used to compare means and variance. <h3>Results</h3> A total of 24 patients were recruited into the study with a mean age of 27.79 years. Results demonstrated that implant position accuracy was significantly superior in the transverse plane (medio-lateral) for the test group (p=0.03). The total duration of the procedure was longer by 8minutes (p=0.047), while surgery time was 15minutes shorter when using ION (p<0.001). This was due to the additional equipment setup time for the test group (mean 23mins, p<0.001). <h3>Conclusion</h3> The study demonstrated that ION may be a useful intra-operative guide to improve implant position in infero-medial orbital defects requiring reconstruction. ION also reduced the time required for intra-orbital dissection and positioning of the implant.

P-43978269-291 - Intraoperative navigation and surgical margins in locally advanced malignant midface tumors.

<h3>Introduction</h3> The surgical treatment of midface tumors is often highly complex. The three-dimensional anatomy of the midface and advanced maxillary tumors make anatomical orientation difficult, which increases the risk of affected surgical margins. The main objective is to answer the question: Does intraoperative navigation improve oncological results in complex midface resections? <h3>Material and Methods</h3> Thirty-two patients with malignant midface advanced tumors were included.16 patients were prospectively selected and surgery was performed with intraoperative navigation (ION). A control group of 16 patients was retrospectively selected and surgery was performed without ION. A systematic margin analysis was performed selecting 6 surgical margins for each surgical piece and 192 surgical margins in total were analyzed. <h3>Results</h3> Squamous carcinoma was the most frequent histological type (56.25% in study group and 68.75% in control group). Complex maxillectomies (types IV-V-VI Brown and Shaw) were performed in 9 of 16 patients in study group (56.25%) and in 2 of 16 (12.5%) in control group. There were 11 of 96 margins affected in study group (11.5%) and 16 of 96 affected margins in control group (16.7%). Chi square test was not statistically significative (p 0.299). The most affected surgical margin was the deep margin in both groups, 9 of 16 (56.25%) in control group and 6 of 11 (54.5%) in the study group. <h3>Conclusion</h3> The use of intraoperative navigation facilitates the resection of advanced midface malignancies and it seems to improve tumor-free margin status with less intraoperative complications. However, further prospective trials with a larger cohort are required to confirm these preliminary results.

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.

The use of intra-operative navigation during complex lumbar spine surgery under spinal anesthesia

BackgroundSpinal anesthesia is a safe and effective alternative to general anesthesia in both simple and complex lumbar surgery with numerous reported advantages leading to increased recent utilization. One potential barrier to the use of spinal anesthesia in lumbar surgery is the popularity of intraoperative computed tomography (CT) imaging. Intraoperative CT necessitates motionless patients and adds time to procedures, issues that may make surgeons hesitant to use concomitant spinal anesthesia. To date, the use of both techniques simultaneously has not been well described. ObjectiveWe propose that single-level lumbar fusions utilizing intraoperative CT scan acquisition and navigated instrumentation are feasible under single-dose spinal anesthesia without detrimental effect on image quality and navigation accuracy or need for spinal anesthetic re-dosing due to the additional time necessary. MethodsWe describe operative characteristics and intra-operative timing for our first five cases of transforaminal lumbar interbody fusion (TLIF) completed with intraoperative CT scan acquisition and navigated instrumentation performed under spinal anesthesia. ResultsThe five patients ranged in age from 59 to 79 years, with an average body mass index of 27.0 kg/m2. The average total operative time for each surgery 109.2 min, including approximately 6.3 min required for CT scan acquisition. There were no complications and post-operative imaging demonstrated no malpositioned pedicle screws. ConclusionSingle-level TLIF procedures utilizing intraoperative CT acquisition and navigated instrumentation can be feasibly completed under single-dose spinal anesthesia without need for intraoperative apneic periods and without deleterious effect on instrumentation accuracy.

Применение интраоперационной навигации в эндоскопической хирургии доброкачественных костно-фиброзных образований околоносовых пазух и основания черепа

Objective. Evaluation of the effectiveness and safety of the use of electromagnetic computer navigation in endoscopic surgery of benign fibro-osseous mass of the paranasal sinuses and skull base. Materials and methods. The retrospective study included 21 patients who underwent endoscopic removal of fibro-osseous mass of paranasal sinuses and skull base at the Burdenko Center from 2010 to 2021. The patients were divided into 2 groups: the 1st group included 10 patients with the use of electromagnetic navigation intraoperatively, the 2nd group included 11 patients who were treated without the use of navigation. Median follow-up was 24 months [IQR 12,00, 48,00]. Results. Most often, patients complained of headache (15; 71,4%). In 14 (66,7%) cases, the ethmoid labyrinth was involved; in 11 (52,3%) cases, the sphenoid sinus; in 15 (71,4%) cases, the base of the skull, with intracranial distribution in 5 (23,8%) cases; and in 8 (38%) cases, the wall of the orbit. Surgical treatment was performed radically in 10 (47,6%) patients. The median intraoperative blood loss was 100.00 mL. Intraoperative complications occurred in 3 (14,3%) patients; postoperative complications, in 2 (9,5%) patients. Pathology recurrence occurred in 4 (19,0%) patients, more often in young people (median age 19,50, р = 0,179). The median duration of hospital stay was 3,00 bed-days. It was found that the localization of pathology in the sphenoid sinus is associated with an increased risk of nonradical removal of the formation (р = 0.009). Factors that could influence the choice of the surgeon in favor of intraoperative navigation include visual impairment in the clinical picture of the disease (p = 0,090) or the absence of difficulty in nasal breathing (p = 0.024); localization of the mass only in the sphenoid sinus (p = 0,063) or with involvement of the base of the skull (p = 0.149). The use of intraoperative navigation slightly increases the radicalness of surgical treatment and reduces the incidence of perioperative complications.

Navigation, mixed reality, and robotics in endoscopic spine surgery

Endoscopic spine surgery (ESS) is an ultra-minimally invasive technique through which spinal pathology can be addressed via sub-centimeter incisions with negligible soft tissue disruption. However, concerns exist regarding the steep learning curve, operative time, and radiation exposure to the surgical team. The use of intraoperative navigation, mixed reality, and robotics in the setting of ESS is currently being explored, and the early evidence suggests that such technologies may help mitigate these issues. The application of these technologies in ESS as well as the associated literature is reviewed herein.

Accuracy of free-hand positioned patient specific implants (PSI) in primary reconstruction after inferior and/or medial orbital wall fractures

BackgroundTo assess the accuracy with which CAD/CAM-fabricated patient-specific titanium implants (PSI) are positioned for inferior and/or medial orbital wall reconstruction without the use of intraoperative navigation. MethodsPatients who underwent a primary reconstruction of the orbital walls with PSI due to fractures were enrolled in this retrospective cohort analysis. The primary outcome variables were the mean surface distances (MSD) between virtually planned and postoperative PSI position and single linear deviations in the x-, y- and z-axis at corresponding reference points. Secondary outcome variables included demographic data, classification of orbital wall defects and clinical outcomes. ResultsA total of 33 PSI (orbital floor n = 22; medial wall, n = 11) were examined in 27 patients. MSD was on a comparable level for the orbital floor and medial wall (median 0.39 mm, range 0.22–1.53 mm vs. median 0.42 mm, range 0.21–0.98 mm; p = 0.56). Single linear deviations were lower for reconstructions of the orbital floor compared to the medial wall (median 0.45 vs. 0.79 mm; p < 0.05). There was no association between the occurrence of diplopia and the accuracy level (p = 0.418). ConclusionsFree-hand positioning of PSI reaches a clinically appropriate level of accuracy, limiting the necessity of navigational systems to selected cases.