Endoscopic resection of primary sinonasal mucosal melanoma with orbital invasion: How I do it.

Primary sinonasal mucosal melanoma is a rare aggressive malignancy. In this video, a case of a 68-year-old female who presented with diplopia for 2 weeks is described. The present video reports the endoscopic endonasal surgical excision of a primary sinonasal mucosal melanoma. The video contains patient's medical history, preoperative radiological evaluations and step-by-step description of surgical steps of the procedure with the utilization of computer-assisted navigation system.

Navigated augmented reality through a head-mounted display leads to low deviation between planned, intra- and postoperative parameters during glenoid component placement of reverse shoulder arthroplasty: a proof-of-concept case series.

BACKGROUND: Navigated augmented reality (AR) through a head-mounted display (HMD) has led to accurate glenoid component placement in reverse shoulder arthroplasty (RSA) in an in-vitro setting. The purpose of this study is to evaluate the deviation between planned, intraoperative, and postoperative inclination, retroversion, entry point, and depth of the glenoid component placement during RSA, assisted by navigated AR through an HMD, in a surgical setting. METHODS: A prospective, multicenter study was conducted. All consecutive patients undergoing RSA in 2 institutions, between August 2021 and January 2023, were considered potentially eligible for inclusion in the study. Inclusion criteria were as follows: age >18 years, surgery assisted by AR through an HMD, and postoperative computed tomography (CT) scans at 6 weeks. All participants agreed to participate in the study and informed consent was provided in all cases. Preoperative CT scans were undertaken for all cases and used for 3-dimensional (3D) planning. Intraoperatively, glenoid preparation and component placement were assisted by a navigated AR system through an HMD in all patients. Intraoperative parameters were recorded by the system. A postoperative CT scan was undertaken at 6 weeks, and 3D reconstruction was performed to obtain postoperative parameters. The deviation between planned, intraoperative, and postoperative inclination, retroversion, entry point, and depth of the glenoid component placement was calculated. Outliers were defined as >5° for inclination and retroversion and >5 mm for entry point. RESULTS: Seventeen patients (9 females, 12 right shoulders) with a mean age of 72.8 ± 9.1 years (range, 47.0-82.0) met inclusion criteria. The mean deviation between intra- and postoperative measurements was 1.5° ± 1.0° (range, 0.0°-3.0°) for inclination, 2.8° ± 1.5° (range, 1.0°-4.5°) for retroversion, 1.8 ± 1.0 mm (range, 0.7-3.0 mm) for entry point, and 1.9 ± 1.9 mm (range, 0.0-4.5 mm) for depth. The mean deviation between planned and postoperative values was 2.5° ± 3.2° (range, 0.0°-11.0°) for inclination, 3.4° ± 4.6° (range, 0.0°-18.0°) for retroversion, 2.0 ± 2.5 mm (range, 0.0°-9.7°) for entry point, and 1.3 ± 1.6 mm (range, 1.3-4.5 mm) for depth. There were no outliers between intra- and postoperative values and there were 3 outliers between planned and postoperative values. The mean time (minutes : seconds) for the tracker unit placement and the scapula registration was 03:02 (range, 01:48 to 04:26) and 08:16 (range, 02:09 to 17:58), respectively. CONCLUSION: The use of a navigated AR system through an HMD in RSA led to low deviations between planned, intraoperative, and postoperative parameters for glenoid component placement.

Comparison of major spine navigation platforms based on key performance metrics: a meta-analysis of 16,040 screws.

PURPOSE: The objective of this meta-analysis is to compare available computer-assisted navigation platforms by key performance metrics including pedicle screw placement accuracy, operative time, neurological complications, and blood loss. METHODS: A systematic review was conducted using major databases for articles comparing pedicle screw accuracy of computer-assisted navigation to conventional (freehand or fluoroscopy) controls via post-operative computed tomography. Outcome data were extracted and pooled by random-effects model for analysis. RESULTS: All navigation platforms demonstrated significant reduction in risk of breach, with Stryker demonstrating the highest accuracy compared to controls (OR 0.16 95% CI 0.06 to 0.41, P < 0.00001, I2 = 0%) followed by Medtronic. There were no significant differences in accuracy or most surgical outcome measures between platforms; however, BrainLab demonstrated significantly faster operative time compared to Medtronic by 30 min (95% CI - 63.27 to - 2.47, P = 0.03, I2 = 74%). Together, there was significantly lower risk of major breach in the navigation group compared to controls (OR 0.42, 95% CI 0.27-0.63, P < 0.0001, I2 = 56%). CONCLUSIONS: When comparing between platforms, Stryker demonstrated the highest accuracy, and Brainlab the shortest operative time, both followed by Medtronic. No significant difference was found between platforms regarding neurologic complications or blood loss. Overall, our results demonstrated a 60% reduction in risk of major breach utilizing computer-assisted navigation, coinciding with previous studies, and supporting its validity. This study is the first to directly compare available navigation platforms offering insight for further investigation and aiding in the institutional procurement of platforms. LEVEL 3 EVIDENCE: Meta-analysis of Level 3 studies.

Accuracy of bony resection under computer-assisted navigation for bone sarcomas around the knee.

BACKGROUND: Computer-assisted navigation has made bone sarcoma resections more precise. However, further clinical studies involving accuracy analyses under navigation are still warranted. METHODS: A retrospective study for analysis of computer-assisted navigation accuracy was carried out. Between September 2008 and November 2017, 39 cases of bone sarcomas around the knee joint were resected under computer-assisted navigation. The control group comprised 117 cases of bone sarcomas around the knee treated by limb salvage surgery wherein bony cutting was achieved freehand. The length difference (LD) was defined as the specimen length minus the planned resection length. The LDs were detected in both groups and compared. The margin accuracy (MA) was defined as the achieved margin minus the desired margin at the bone cutting site and was detected in the navigation group. RESULTS: The LDs between the postoperative specimen length and the preoperative planned length were compared. In the navigation group, the LD was 0.5 ± 2.5 mm (range, - 5 to 5 mm), while in the freehand group, the LD was 3.4 ± 9.6 mm (range, - 20 to 29 mm), with a significant difference (P < 0.01). In the absolute value analysis, the LD absolute value was 2.0 ± 1.6 mm in the navigation group and 8.3 ± 6.0 mm in the freehand group, with a significant difference (P < 0.01). In the navigation group, the MA was 0.3 ± 1.5 mm (range, - 3 to 3 mm) and the MA absolute value was 1.1 ± 1.0 mm. CONCLUSIONS: Better accuracy can be achieved when computer-assisted navigation is conducted for bone sarcoma resection around the knee. LEVEL OF EVIDENCE: IV.

Use of intraoperative technology in total knee arthroplasty is not associated with reductions in postoperative pain.

PURPOSE: Our systematic review and meta-analysis sought to assess how technology-assistance impacts (1) post-operative pain and (2) opioid use in patients undergoing primary total knee arthroplasty (TKA). METHODS: Four online databases were queried for studies published up to October 2021 that reported on pain and opioid usage between technology-assisted and manual TKA (mTKA) patients. Mantel-Haenszel (M-H) models were utilized to calculate pooled mean difference (MDs) and 95% confidence interval (CIs). Subgroup analyses were conducted to isolate robotic-arm assisted (RAA) and computed-assisted navigation (CAN) cohorts. Risk of bias was assessed for all included non-randomized studies with the Methodological Index for Non-Randomized Studies (MINORS) tool. For the randomized control trials included in our study, the Detsky scale was applied. RESULTS: Our analysis included 31 studies, reporting on a total of 761,300 TKAs (mTKA: n = 753,554; Computer-Assisted Navigation (CAN): n = 1,309; Robotic-Arm Assisted (RAA): n = 6437). No differences were demonstrated when evaluating WOMAC (MD: 0.00, 95% CI - 0.69 to 0.69; p = 1.00), KSS (MD: 0.01, 95% CI - 1.46 to 1.49; p = 0.99), KOOS (MD - 2.91, 95% CI - 6.17 to 0.34; p = 0.08), and VAS (MD - 0.54, 95% CI - 1.01 to - 0.007; p = 0.02) pain scores between cohorts. There was mixed evidence regarding how opioid consumption differed between TKA techniques. CONCLUSION: The present analysis demonstrated no difference in terms of pain across a variety of utilized patient-reported pain measurements. However, there were mixed results regarding how opioid consumption varied between manual and technology-assisted cohorts, particularly in the immediate post-operative period. LEVEL OF EVIDENCE: III.

The learning curve associated with imageless navigation in total knee arthroplasty.

INTRODUCTION: Computer-assisted navigation systems (CAS) are increasingly being integrated into total knee arthroplasty (TKA) procedures, but perceptions of associated learning curve and increased operative time continue to curtail uptake. Newer-generation navigational systems aim to streamline integration into surgical workflow to mitigate increases in operative time. Here, we assess the impact of a novel imageless CAS on operative time for TKA. METHODS: A retrospective analysis of prospectively collected data of a cohort of patients undergoing primary unilateral TKA with one of three surgeons between October 2019 and March 2020 was conducted. Consecutive cases using a novel imageless CAS were included in analysis. For each surgeon, average operative time was recorded and compared in sequential five-case cohorts to average operative time for the same procedure performed conventionally using a two-tailed t test. RESULTS: Average conventional operative times were 95.9 ± 15.0, 86.6 ± 13.7, and 116.9 ± 25.1 min for the three surgeons. Initial CAS-assisted operative times increased to 107.0 ± 9.8 (p = 0.07) and 102.4 ± 13.2 (p = 0.06) min for Surgeons 1 and 2 and decreased to 113.2 ± 9.8 min (p = 0.52) for Surgeon 3. Most recent CAS-assisted operative times were 94.8 ± 13.9 (p = 0.88), 88.7 ± 15.3 (p = 0.84), and 104.8 ± 13.2 (p = 0.12) min as compared to pre-CAS. Absolute differences for the most recent navigated procedures ranged from 12.1 min faster to 2.0 min slower. CONCLUSION: The learning curve for TKA navigation may be as few as 10 cases, and any associated increases in operative time may be transient and non-significant. Moreover, navigation may ultimately speed operative time, perhaps as the result of enhanced intraoperative assessment of alignment.

The accuracy of component positioning during revision total hip arthroplasty using 3D optical computer-assisted navigation.

INTRODUCTION: Despite the excellent outcomes associated with primary total hip arthroplasty (THA), implant failure and revision continue to burden the healthcare system. The use of computer-assisted navigation (CAN) offers the potential for more accurate placement of hip components during surgery. While intraoperative CAN systems have been shown to improve outcomes in primary THA, their use in the context of revision total hip arthroplasty (rTHA) has not been elucidated. We sought to investigate the validity of using CAN during rTHA. METHODS: A retrospective analysis was performed at an academic medical institution identifying all patients who underwent rTHA using CAN from 2016-2019. Patients were 1:1 matched with patients undergoing rTHA without CAN (control) based on demographic data. Cup anteversion, inclination, change in leg length discrepancy (ΔLLD) and change in femoral offset between pre- and post-operative plain weight-bearing radiographic images were measured and compared between both groups. A safety target zone of 15-25° for anteversion and 30-50° for inclination was used as a reference for precision analysis of cup position. RESULTS: Eighty-four patients were included: 42 CAN cases and 42 control cases. CAN cases displayed a lower ΔLLD (5.74 ± 7.0 mm vs 9.13 ± 7.9 mm, p = 0.04) and greater anteversion (23.4 ± 8.53° vs 19.76 ± 8.36°, p = 0.0468). There was no statistical difference between the proportion of CAN or control cases that fell within the target safe zone (40% vs 20.9%, p = 0.06). Femoral offset was similar in CAN and control cases (7.63 ± 5.84 mm vs 7.14 ± 4.8 mm, p = 0.68). CONCLUSION: Our findings suggest that the use of CAN may improve accuracy in cup placement compared to conventional methodology, but our numbers are underpowered to show a statistical difference. However, with a ΔLLD of ~ 3.4 mm, CAN may be useful in facilitating the successful restoration of pre-operative leg length following rTHA. Therefore, CAN may be a helpful tool for orthopedic surgeons to assist in cup placement and LLD during complex revision cases.

Percutaneous thoraco-lumbar-sacral pedicle screw placement accuracy results from a multi-center, prospective clinical study using a skin marker-based optical navigation system.

STUDY DESIGN: Prospective multi-center study. OBJECTIVE: The study aimed to evaluate the accuracy of pedicle screw placement using a skin marker-based optical surgical navigation system for minimal invasive thoraco-lumbar-sacral pedicle screw placement. METHODS: The study was performed in a hybrid Operating Room with a video camera-based navigation system integrated in the imaging hardware. The patient was tracked with non-invasive skin markers while the instrument tracking was via an on-shaft optical marker pattern. The screw placement accuracy assessment was performed by three independent reviewers, using the Gertzbein grading. The screw placement time as well as the staff and patient radiation doses was also measured. RESULTS: In total, 211 screws in 39 patients were analyzed for screw placement accuracy. Of these 32.7% were in the thoracic region, 59.7% were in the lumbar region, and 7.6% were in the sacral region. An overall accuracy of 98.1% was achieved. No screws were deemed severely misplaced (Gertzbein grading 3). The average time for screw placement was 6 min and 25 secs (± 3 min 33 secs). The average operator radiation dose per subject was 40.3 µSv. The mean patient effective dose (ED) was 11.94 mSv. CONCLUSION: Skin marker-based ON can be used to achieve very accurate thoracolumbarsacral pedicle screw placements.

Does MIS-TLIF or TLIF result in better pedicle screw placement accuracy and clinical outcomes with navigation guidance?

BACKGROUND: Although previous studies have suggested that navigation can improve the accuracy of pedicle screw placement, few studies have compared navigation-assisted transforaminal lumbar interbody fusion (TLIF) and navigation-assisted minimally invasive TLIF (MIS-TLIF). The entry point of pedicle screw insertion in navigation-assisted MIS-TLIF (NM-TLIF) may deviate from the planned entry point due to an uneven bone surface, which may result in misplacement. The purpose of this study was to explore the pedicle screw accuracy and clinical consequences of MIS-TLIF and TLIF, both under O-arm navigation, to determine which surgical method is better. METHODS: A retrospective study of 54 patients who underwent single-segment NM-TLIF or navigation-assisted TLIF (N-TLIF) was conducted. In addition to the patients' demographic characteristics, intraoperative indicators and complications, the Oswestry Disability Index (ODI) and visual analog scale (VAS) score were recorded and analyzed preoperatively and at the 1-, 6-, and 12-month and final postoperative follow-ups. The clinical qualitative accuracy and absolute quantitative accuracy of pedicle screw placement were assessed by postoperative CT. Multifidus muscle injury was evaluated by T2-weighted MRI. RESULTS: Compared with N-TLIF, NM-TLIF was more advantageous in terms of the incision length, intraoperative blood loss, drainage volume, time to ambulation, length of hospital stay, blood transfusion rate and analgesia rate (P < 0.05). The ODI and VAS scores for low back pain were better than those of N-TLIF at 1 month and 6 months post-surgery (P < 0.05). There was no significant difference in the clinical qualitative screw placement accuracy (97.3% vs. 96.2%, P > 0.05). The absolute quantitative accuracy results showed that the axial translational error, sagittal translational error, and sagittal angle error in the NM-TLIF group were significantly greater than those in the N-TLIF group (P < 0.05). The mean T2-weighted signal intensity of the multifidus muscle in the NM-TLIF group was significantly lower than that in the N-TLIF group (P < 0.05). CONCLUSIONS: Compared with N-TLIF, NM-TLIF has the advantages of being less invasive, yielding similar or better screw placement accuracy and achieving better symptom relief in the midterm postoperative recovery period. However, more attention should be given to real-time adjustment for pedicle insertion in NM-TLIF rather than just following the entry point and trajectory of the intraoperative plan.

Real-time navigation guidance with intraoperative CT imaging for pedicle screw placement using an augmented reality head-mounted display: a proof-of-concept study.

OBJECTIVE: Augmented reality (AR) has the potential to improve the accuracy and efficiency of instrumentation placement in spinal fusion surgery, increasing patient safety and outcomes, optimizing ergonomics in the surgical suite, and ultimately lowering procedural costs. The authors sought to describe the use of a commercial prototype Spine AR platform (SpineAR) that provides a commercial AR head-mounted display (ARHMD) user interface for navigation-guided spine surgery incorporating real-time navigation images from intraoperative imaging with a 3D-reconstructed model in the surgeon's field of view, and to assess screw placement accuracy via this method. METHODS: Pedicle screw placement accuracy was assessed and compared with literature-reported data of the freehand (FH) technique. Accuracy with SpineAR was also compared between participants of varying spine surgical experience. Eleven operators without prior experience with AR-assisted pedicle screw placement took part in the study: 5 attending neurosurgeons and 6 trainees (1 neurosurgical fellow, 1 senior orthopedic resident, 3 neurosurgical residents, and 1 medical student). Commercially available 3D-printed lumbar spine models were utilized as surrogates of human anatomy. Among the operators, a total of 192 screws were instrumented bilaterally from L2-5 using SpineAR in 24 lumbar spine models. All but one trainee also inserted 8 screws using the FH method. In addition to accuracy scoring using the Gertzbein-Robbins grading scale, axial trajectory was assessed, and user feedback on experience with SpineAR was collected. RESULTS: Based on the Gertzbein-Robbins grading scale, the overall screw placement accuracy using SpineAR among all users was 98.4% (192 screws). Accuracy for attendings and trainees was 99.1% (112 screws) and 97.5% (80 screws), respectively. Accuracy rates were higher compared with literature-reported lumbar screw placement accuracy using FH for attendings (99.1% vs 94.32%; p = 0.0212) and all users (98.4% vs 94.32%; p = 0.0099). The percentage of total inserted screws with a minimum of 5° medial angulation was 100%. No differences were observed between attendings and trainees or between the two methods. User feedback on SpineAR was generally positive. CONCLUSIONS: Screw placement was feasible and accurate using SpineAR, an ARHMD platform with real-time navigation guidance that provided a favorable surgeon-user experience.

Computer assisted total knee arthroplasty: 2.5 years follow-up of 200 cases.

INTRODUCTION: Computer assisted surgery in total knee arthroplasty (TKA) should improve accuracy of both femoral and tibial components placement. This study evaluated the functional outcomes of computer navigated total knee arthroplasty through the Knee Society Score (KSS) and Tegner Lysholm Knee Scoring Scale (TLKSS). MATERIALS AND METHODS: Between September 2007 and February 2013, 180 patients (200 knees; 109 females and 71 males; mean age: 64 years) undergoing computer-assisted TKA were recruited. Plain radiographs and CT scans were performed post-operatively to evaluate alignment. The clinical outcomes were measured using the KSS and TLKSS pre-operatively and after 6, 12 and 36 months. RESULTS: The mean follow-up duration was 2.5 years. The mean tourniquet time was 72 ± 13.4 min, and patients received an average of 0.6 ± 0.82 units of blood after surgery. The average preoperative KSS functional score of 44.6 ± 13.7 improved to 80.4 ± 16.4 after 2 years. The average preoperative TLKSS improved to 71.4 ± 13.5 after 2 years. The mechanical axis was within ±3° in all patients. No axial malalignments were observed on TC Scan. Three patients (1.6% of cases) required revision. CONCLUSION: Computer assisted TKA allows reproducible alignment and kinematics, reducing outliers, provides ligament balancing and ensures good short term outcomes in terms of KSS functional score and TLKSS.

Evaluating Alternate Registration Planes for Imageless, Computer-Assisted Navigation During Total Hip Arthroplasty.

BACKGROUND: 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. METHODS: 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. RESULTS: 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). CONCLUSION: 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.

The feasibility of computer-assisted 3D navigation in multiple-level lateral lumbar interbody fusion in combination with posterior instrumentation for adult spinal deformity.

OBJECTIVE: The lateral lumbar interbody fusion (LLIF) technique is used to treat many common spinal degenerative pathologies including kyphoscoliosis. The use of spinal navigation for LLIF has not been broadly adopted, especially in adult spinal deformity. The purpose of this study was to evaluate the feasibility as well as the intraoperative and navigation-related complications of computer-assisted 3D navigation (CaN) during multiple-level LLIF for spinal deformity. METHODS: Retrospective analysis of clinical and operative characteristics was performed for all patients > 18 years of age who underwent multiple-level CaN LLIF combined with posterior instrumentation for adult spinal deformity at the University of Michigan between 2014 and 2020. Intraoperative CaN-related complications, LLIF approach-related postoperative complications, and medical postoperative complications were assessed. RESULTS: Fifty-nine patients were identified. The mean age was 66.3 years (range 42-83 years) and body mass index was 27.6 kg/m2 (range 18-43 kg/m2). The average coronal Cobb angle was 26.8° (range 3.6°-67.0°) and sagittal vertical axis was 6.3 cm (range -2.3 to 14.7 cm). The average number of LLIF and posterior instrumentation levels were 2.97 cages (range 2-5 cages) and 5.78 levels (range 3-14 levels), respectively. A total of 6 intraoperative complications related to the LLIF stage occurred in 5 patients. Three of these were CaN-related and occurred in 2 patients (3.4%), including 1 misplaced lateral interbody cage (0.6% of 175 total lateral cages placed) requiring intraoperative revision. No patient required a return to the operating room for a misplaced interbody cage. A total of 12 intraoperative complications related to the posterior stage occurred in 11 patients, with 5 being CaN-related and occurring in 4 patients (6.8%). Univariate and multivariate analyses revealed no statistically significant risk factors for intraoperative and CaN-related complications. Transient hip weakness and numbness were found to be in 20.3% and 22.0% of patients, respectively. At the 1-month follow-up, weakness was observed in 3.4% and numbness in 11.9% of patients. CONCLUSIONS: Use of CaN in multiple-level LLIF in the treatment of adult spinal deformity appears to be a safe and effective technique. The incidence of approach-related complications with CaN was 3.4% and cage placement accuracy was high.

Complications of computer-assisted navigation in total knee replacement: retrospective cohort of eight hundred and seventy eight consecutive knees.

PURPOSE: The main objective was to analyze the computer-assisted navigation (CAN)-specific complications that forced to switch to conventional procedure in primary total knee replacement (TKR). The secondary objective was to determine the influence of those complications on TKR short-term survival. METHODS: Retrospective study of 878 primary TKR in 753 patients. Two consecutive versions of the OrthoPilot navigation system (Braun Aesculap, Germany) were used during the study time. Specific complications of CAN were defined as those due to the instrumentation (hardware or software failures), which were classified in one of two categories according to whether they occurred during the registration or tracking process. RESULTS: There were 20 (2.3%) complications related to the navigation system use that forced to switch to conventional surgery: in 11 (1.2%) knees due to loosening of the tracking pins, and in the other nine (1.0%) there were information system failures. There was a trend for a higher conversion rate to conventional surgery with the use of the first version of the software. There were no fractures, infections, or nerve injuries at the pin site. We found no differences in the distribution of baseline variables among those with or without conversion to conventional surgery. There was no significant difference (p = 0.488) in the two year survival between patients with or without conversion. CONCLUSION: CAN for primary TKR is a safe method with few specific complications that forced to switch from the navigated to the conventional procedure. Conversion to conventional surgery did not affect the short-term survival of TKR.

Transnasal endoscopic repair of adult spontaneous cerebrospinal fluid rhinorrhea with assistance of computer-assisted navigation system: an analysis of 21 cases.

OBJECTIVE: The purpose of this study was to investigate and summarize the characteristics of spontaneous cerebrospinal fluid rhinorrhea cases and the efficacy of transnasal endoscopic repair of spontaneous cerebrospinal fluid rhinorrhea with the assistance of computer-assisted navigation system. METHODS: This is a retrospective study including 21 adult patients with spontaneous cerebrospinal fluid rhinorrhea who underwent transnasal endoscopic repair with the assistance of computer-assisted navigation system between January 2007 and December 2017. Data collected included patient demographics, body mass index, patient symptoms, biochemical findings, radiographic findings, location of defect, type and size of defect, type of repair, follow-up time, reoccurrence, and complications. RESULTS: Spontaneous cerebrospinal fluid rhinorrhea was more commonly seen in females who were middle-aged and overweight in our series. The effluent was determined as cerebrospinal fluid by testing of glucose concentration and ß2-transferrin. The location of the lesion was determined by rigid nasal endoscopy combined with radiologic study. Intraoperatively, the skull base defects were found most frequently on the ethmoid roof in 12 cases (57.1%), followed by the cribriform plate in seven cases (33.3%), and sphenoid sinus in two cases (9.5%). The size of the skull base defect was < 5 mm in 13 cases, 5 mm ~ 10 mm in six cases and two cases involved defects of ≥ 10 mm. The graft materials were chosen based on the size of the defect. In small leaks, the thigh muscle was dumbbell-shaped herniated into the bony defect, reinforced by fascia lata. Larger defects were packed with the anterior part of middle turbinate with an overlay of fascia lata. All 21 patients had no recurrence of cerebrospinal fluid rhinorrhea during the follow-up period, which ranged from 11 to 24 months. CONCLUSION: The transnasal endoscopic approach with assistance of computer-assisted navigation system is a safe and effective procedure for the repair of spontaneous cerebrospinal fluid rhinorrhea.

[Accuracy Verification of Robot-assisted Mandibular Reconstruction Surgery].

Mandible is an important bone of the head and neck. Mandibular defects not only affect patient's face, but also impede patient's daily functions, such as chewing, speech, and so on. Fibular transplantation for mandibular reconstruction is the common method, which requests high accuracy of bone positioning and posture adjustment. Therefore, a robotic system for mandibular reconstruction surgery with fibula flaps was designed to assist surgeons to hold and locate bones, and the model comparison experiments were conducted. The results showed that the robotic system can assist surgeons for mandibular reconstruction to improve quality of surgery.

CAMISS Concept and Its Clinical Application.

This chapter intends to provide an overview of computer-assisted minimally invasive spine surgery (CAMISS) and its clinical application. Since minimally invasive spine surgery was first brought out, the concept of decreasing the damage to patient was soon become popular. However, without the proper surgical field, the spine surgery can be very dangerous. The minimally invasive concept was restricted in promotion until the computer-assisted navigation system break down the obstacles. The CAMISS technique achieves better clinical outcomes with the advantages of smaller invasion, less injury, and better recovery and also became the gold standard for spine surgery. The spatial distribution concept and the respiration-induced motion concept help in promoting the accuracy and safety of the CAMISS concept. The CAMISS concept also facilitated the developing of robotic techniques, which was considered as the future of orthopedic surgery.

Morbidity and Safety of Iliac Crest Reference Array Pins in Navigated Total Hip Arthroplasty: A Prospective Cohort Study.

BACKGROUND: Navigated total hip arthroplasty (THA) can employ intra-osseous pins through a separate incision to secure reference arrays to the iliac crest. This study is the first to investigate the consequences of pin use in THA in vivo. METHODS: A prospective, consecutive series of 43 patients presenting for navigated THA were included. Two temporary 125 × 4 mm Schanz screws were inserted into the iliac crest for the attachment of a reference array. Telephone follow-up occurred at 6 and 12 weeks post-operatively. Patients were asked about pain, interference with daily activities, how often the wound was noticed, and duration of discomfort. Patient body mass index was recorded. RESULTS: The follow-up rate was 100%. Pin site pain at any time post-operatively was reported by 24 patients (56%). This improved to 30%, 9%, and 2% at 3, 6, and 12 weeks, respectively. On average, pain lasted for 16 days total. The most common complaints after pain were clothing discomfort (23%), pain when wearing a belt (12%), or pain when mobilizing (9%). For the majority (98%) of patients, all symptoms had resolved by 12 weeks. There was no nerve injury, pin site fracture, infection, or screw breakage. Patients with body mass index greater than 30 kg/m2 were up to 3 times more likely to experience pin site pain (P = .05), and had a longer duration of pain (P = .04). CONCLUSION: Surgeons and patients should be aware that using navigational pins for array fixation carries low complication rates but often will cause pain and irritation that resolves in the short term.

A new system of computer-assisted navigation leading to reduction in operating time in uncemented total hip replacement in a matched population.

Computer-assisted navigation techniques are used to optimise component placement and alignment in total hip replacement. It has developed in the last 10 years but despite its advantages only 0.3% of all total hip replacements in England and Wales are done using computer navigation. One of the reasons for this is that computer-assisted technology increases operative time. A new method of pelvic registration has been developed without the need to register the anterior pelvic plane (BrainLab hip 6.0) which has shown to improve the accuracy of THR. The purpose of this study was to find out if the new method reduces the operating time. This was a retrospective analysis of comparing operating time in computer navigated primary uncemented total hip replacement using two methods of registration. Group 1 included 128 cases that were performed using BrainLab versions 2.1-5.1. This version relied on the acquisition of the anterior pelvic plane for registration. Group 2 included 128 cases that were performed using the newest navigation software, BrainLab hip 6.0 (registration possible with the patient in the lateral decubitus position). The operating time was 65.79 (40-98) minutes using the old method of registration and was 50.87 (33-74) minutes using the new method of registration. This difference was statistically significant. The body mass index (BMI) was comparable in both groups. The study supports the use of new method of registration in improving the operating time in computer navigated primary uncemented total hip replacements.

A new technique for minimally invasive irreversible electroporation of tumors in the head and body of the pancreas.

BACKGROUND: Palliative irreversible electroporation of pancreatic adenocarcinomas is rapidly gaining in interest since a large proportion of these patients cannot be radically resected. METHODS: This is a description of a minimally invasive approach to irreversible electroporation of pancreatic tumors using computer-assisted navigation, laparoscopy and laparoscopic ultrasound to correctly guide electrodes into the tissue. RESULTS: The procedure is presented. CONCLUSION: Minimally invasive irreversible electroporation of pancreatic tumors through computer-assisted navigation of needles during laparoscopy is a feasible and accurate approach.