Does a Commercially Available Augmented Reality-based Portable Hip Navigation System Improve Cup Positioning During THA Compared With the Conventional Technique? A Randomized Controlled Study

BACKGROUND

Portable hip navigation systems have been developed to combine the accuracy of cup positioning by large console navigation systems with the ease of use and convenience of conventional surgical techniques. Although a novel augmented reality-based portable hip navigation system using a smartphone (AR navigation) has become available recently, no studies, to our knowledge, have compared commercially available AR navigation with the conventional technique. Additionally, no studies, except for those from designer-surgeon series, have demonstrated the results of AR navigation.

QUESTIONS/PURPOSES

(1) Does intraoperative use of commercially available AR navigation improve cup positioning compared with the conventional technique? (2) Are operative factors, clinical scores, and postoperative course different between the two groups?

METHODS

In this randomized trial, 72 patients undergoing THA were randomly assigned to undergo either commercially available AR navigation or a conventional technique for cup placement. All patients received the same cementless acetabular cups through a posterior approach in the lateral decubitus position. The primary outcome of the present study was cup positioning, including the absolute differences between the intended target and angle achieved, as well as the number of cups inside the Lewinnek safe zone. Our target cup position was 40° abduction and 20° anteversion. Secondary outcomes were operative factors, between-group difference in improvement in the Hip Disability and Osteoarthritis Outcome Score (HOOS), and the postoperative course, including the operative time (between the start of the surgical approach and skin closure), procedure time (between the first incision and skin closure, including the time to insert pins, registration, and transfer and redrape patients in the navigation group), time taken to insert pins and complete registration in the navigation group, intraoperative and postoperative complications, and reoperations. The minimum follow-up period was 6 months, because data regarding the primary outcome-cup positioning-were collected within 1 week after surgery. The between-group difference in improvement in HOOS, which was the secondary outcome, was much lower than the minimum clinically important difference for the HOOS. No patients in either group were lost to follow-up, and there was no crossover (the randomized treatment was performed in all patients, so there was no difference between an intention-to-treat and a per-protocol analysis).

RESULTS

The use of the commercially available AR navigation slightly improved cup positioning compared with the conventional technique in terms of the absolute difference between the desired and achieved amounts of cup abduction and anteversion (which we defined as "absolute differences"; median 1° [IQR 0° to 4.0°] versus median 5° [IQR 3.0° to 7.5°], difference of medians 4°; p < 0.001 and median 2° [IQR 1.9° to 3.7°] versus median 5° [IQR 3.2° to 9.7°], difference of medians 2°; p = 0.001). A higher proportion of cups were placed inside the Lewinnek safe zone in the navigation group than in the control group (94% [34 of 36] compared with 64% [23 of 36]; p < 0.001). Median operative times were not different between the two groups (58 minutes [IQR 49 to 72 minutes] versus 57 minutes [IQR 49 to 69 minutes], difference of medians 1 minute; p = 0.99). The median procedure time was longer in the navigation group (95 minutes [IQR 84 to 109 minutes] versus 57 minutes [IQR 49 to 69 minutes], difference of medians 38 minutes; p < 0.001). There were no differences between the two groups in improvement in HOOS (27 ± 17 versus 28 ± 19, mean difference -1 [95% CI -9.5 to 7.4]; p = 0.81). In the navigation group, no complications occurred in the pin sites; however, one anterior dislocation occurred. In the conventional group, one hip underwent reoperation because of a deep infection.

CONCLUSION

Although the use of commercially available AR navigation improved cup positioning in THA, the improvement in clinical scores and postoperative complication rates were not different between the two groups, and the overall magnitude of the difference in accuracy was small. Future studies will need to determine whether the improvement in the percentage of hips inside the Lewinnek safe zone results in differences in late dislocation or polyethylene wear, and whether such benefits-if any-justify the added costs and surgical time. Until or unless more compelling evidence in favor of the new system emerges, we recommend against widespread use of the system in clinical practice.

LEVEL OF EVIDENCE

Level Ⅱ, therapeutic study.

Pedicle screw placement accuracy in robot-assisted versus image-guided freehand surgery of thoraco-lumbar spine (ROBARTHRODESE): study protocol for a single-centre randomized controlled trial

BACKGROUND

Robotic spinal surgery may result in better pedicle screw placement accuracy, and reduction in radiation exposure and length of stay, compared to freehand surgery. The purpose of this randomized controlled trial (RCT) is to compare screw placement accuracy of robot-assisted surgery with integrated 3D computer-assisted navigation versus freehand surgery with 2D fluoroscopy for arthrodesis of the thoraco-lumbar spine.

METHODS

This is a single-centre evaluator-blinded RCT with a 1:1 allocation ratio. Participants (n = 300) will be randomized into two groups, robot-assisted (Mazor X Stealth Edition) versus freehand, after stratification based on the planned number of pedicle screws needed for surgery. The primary outcome is the proportion of pedicle screws placed with grade A accuracy (Gertzbein-Robbins classification) on postoperative computed tomography images. The secondary outcomes are intervention time, operation room occupancy time, length of stay, estimated blood loss, surgeon's radiation exposure, screw fracture/loosening, superior-level facet joint violation, complication rate, reoperation rate on the same level or one level above, functional and clinical outcomes (Oswestry Disability Index, pain, Hospital Anxiety and Depression Scale, sensory and motor status) and cost-utility analysis.

DISCUSSION

This RCT will provide insight into whether robot-assisted surgery with the newest generation spinal robot yields better pedicle screw placement accuracy than freehand surgery. Potential benefits of robot-assisted surgery include lower complication and revision rates, shorter length of stay, lower radiation exposure and reduction of economic cost of the overall care.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05553028. Registered on September 23, 2022.

Adverse Events Associated With Image-Guided Sinus Navigation in Endoscopic Sinus Surgery: A MAUDE Database Analysis

OBJECTIVE

The utilization of image-guided navigation during endoscopic sinus surgery (ESS) has increased significantly since its introduction. However, the most common associated complications are still unknown. This study describes and analyzes adverse events related to image-guided ESS.

STUDY DESIGN

Cross-sectional analysis.

SETTING

The Food and Drug Administration's 2018-2022 MAUDE database (Manufacturer and User Facility Device Experience).

METHODS

The MAUDE database was searched for all reports on adverse events involving sinus navigation systems used in ESS from 2018 to 2022. Reported events were reviewed and categorized.

RESULTS

During the study period, there were 1857 adverse events from 1565 reports, which were divided into device-related (n = 1834, 98.8%) and patient-related (n = 23, 1.2%) complications. The most common device-related complications were nonfunctionality of the system (n = 512, 27.9%), device imprecision (n = 427, 23.3%), and device sensing problems (n = 277, 15.1%). The most common patient-related complications were cerebrospinal fluid (CSF) leak (n = 14, 60.9%), intracranial injury (n = 4, 17.4%), and bleeding/hemorrhage (n = 3, 13.1%). Imprecision was associated with increased risk of navigation abortion by the surgeon (odds ratio, 1.50 [95% CI, 1.38-1.65]; P < .001) and increased risk of CSF leak (odds ratio, 16.5 [95% CI, 3.66-74.0]; P < .001) as compared with other device-related complications.

CONCLUSIONS

The most commonly reported device- and patient-related adverse events associated with image-guided sinus navigation systems were device nonfunction, imprecision, device sensing difficulties, and CSF leak. When imprecise navigation occurred, there was an increased likelihood of CSF leak and navigation abortion by the surgeon. Health care providers should be mindful of these possible complications when electing to use image-guided sinus navigation during ESS.

Tips and pitfalls to improve accuracy and reduce radiation exposure in intraoperative CT navigation for pediatric scoliosis: a systematic review

BACKGROUND CONTEXT

An increasing number of medical centers are adopting an intraoperative computed tomography (iCT) navigation system (iCT-Navi) to provide three-dimensional navigation for pediatric scoliosis surgery. While iCT-Navi has been reported to provide higher pedicle screw (PS) insertion accuracy, it may also result in higher radiation exposure to the patient. What innovations and studies have been introduced to reduce radiation exposure and further improve PS insertion?

PURPOSE

Evaluate the level of evidence and quality of papers while categorizing the tips and pitfalls regarding pediatric scoliosis surgery using iCT-Navi. Compare iCT-Navi with other methods, including preoperative CT navigation.

STUDY DESIGN

Systematic review.

PATIENT SAMPLE

Articles on pediatric scoliosis surgery with iCT-Navi published through to June 2022.

OUTCOME MEASURES

PS perforation rate and patient intraoperative radiation dose.

METHODS

Following PRISMA guidelines, the Cochrane Library, Google Scholar, and PubMed databases were searched for articles satisfying the criteria of iCT-Navi use and pediatric scoliosis surgery. The level of evidence and quality of the articles meeting the criteria were evaluated according to the guidelines of the North American Spine Society and American Academy of Orthopedic Surgeons, respectively. The articles were also categorized by theme and summarized in terms of PS insertion accuracy and intraoperative radiation dose. The origins and characteristics of five major classification methods of PS perforation grade were summarized as well.

RESULTS

The literature search identified 811 studies, of which 20 papers were included in this review. Overall, 513 pediatric scoliosis patients (381 idiopathic, 44 neuromuscular, 39 neurofibromatosis type 1, 28 congenital, 14 syndromic, seven other) were evaluated for PS perforations among 6,209 iCT-Navi insertions. We found that 232 (3.7%) screws were judged as major perforations (G2 or G3), 55 (0.9%) screws were judged as dangerous deviations (G3), and seven (0.1%) screws were removed. There were no reports of neurovascular injury caused by PSs. The risk factors for PS perforation included more than six vertebrae distance from the reference frame, more than nine consecutive insertions, upper thoracic level, thinner pedicle, upper instrumented vertebra proximity, short stature, and female. The accuracy of PS insertion did not remarkably decrease when the radiation dose was reduced to 1/5 or 1/10 by altering the iCT-Navi protocol.

CONCLUSIONS

iCT-Navi has the potential to reduce PS perforation rates compared with other methods. The use of low-dose radiation protocols may not significantly affect PS perforation rates. Although several risk factors for PS perforation and measures to reduce radiation dose have been reported, the current evidence is limited by a lack of consistency in classifying PS perforation and evaluating patient radiation dose among studies. The standardization of several outcome definitions is recommended in this rapidly developing field.

Augmented reality in minimally invasive spine surgery: early efficiency and complications of percutaneous pedicle screw instrumentation

BACKGROUND CONTEXT

Augmented reality (AR) employs an optical projection directly onto the user's retina, allowing complex image overlay on the natural visual field. In general, pedicle screw accuracy rates have improved with increasingly use of technology, with navigation-based instrumentation described as accurate in 89%-100% of cases. Emerging AR technology in spine surgery builds upon current spinal navigation to provide 3-dimensional imaging of the spine and powerfully reduce the impact of inherent ergonomic and efficiency difficulties.

PURPOSE

This publication describes the first known series of in vivo pedicle screws placed percutaneously using AR technology for MIS applications.

STUDY DESIGN / SETTING

After IRB approval, 3 senior surgeons at 2 institutions contributed cases from June, 2020 - March, 2022. 164 total MIS cases in which AR used for placement of percutaneous pedicle screw instrumentation with spinal navigation were identified prospectively.

PATIENT SAMPLE

155 (94.5%) were performed for degenerative pathology, 6 (3.6%) for tumor and 3 (1.8%) for spinal deformity.  These cases amounted to a total of 606 pedicle screws; 590 (97.3%) were placed in the lumbar spine, with 16 (2.7%) thoracic screws placed.

OUTCOME MEASURES

Patient demographics and surgical metrics including total posterior construct time (defined as time elapsed from preincision instrument registration to final screw placement), clinical complications and instrumentation revision rates were recorded in a secure and de-identified database.

METHODS

The AR system used features a wireless headset with transparent near-eye display which projects intra-operative 3D imaging directly onto the surgeon's retina. After patient positioning, 1 percuntaneous and 1 superficial reference marker are placed. Intra-operative CT data is processed to the headset and integrates into the surgeon's visual field creating a "see-through" 3D effect in addition to 2D standard navigation images. MIS pedicle screw placement is then carried out percutaneously through single line of sight using navigated instruments.

RESULTS

Time elapsed from registration and percutaneous approach to final screw placement averaged 3 minutes and 54 seconds per screw.  Analysis of the learning curve revealed similar surgical times in the early cases compared to the cases performed with more experience with the system.  No instrumentation was revised for clinical or radiographic complication at final available follow-up ranging from 6-24 months. A total of 3 screws (0.49%) were replaced intra-operatively. No clinical effects via radiculopathy or neurologic deficit postoperatively were noted.

CONCLUSIONS

This is the first report of the use of AR for placement of spinal pedicle screws using minimally invasive techniques.   This series of 164 cases confirmed efficiency and safety of screw placement with the inherent advantages of AR technologies over legacy enabling technologies.

Surgical Pitfalls in Bertolotti's syndrome management: A case report

RATIONALE

Bertolotti's syndrome is one of the differential causes of low back pain, especially within young people. The etiopathogenesis of the typical paramedian low back pain, associated with Bertolotti's syndrome remains controversial, and there is no worldwide acceptance of treatment.

PATIENT CONCERNS

This article presents the authors experience with surgical treatment of symptomatic patients with Bertolotti's syndrome.

DIAGNOSES

Retrospective study of a selected series of patients with symptomatic Bertolotti's syndrome submitted to surgical treatment.

INTERVENTIONS

This study included 16 patients, being 8 submitted to the new modified mini-open tubular microsurgical transverse processectomy, Among those patients, intraoperative fluoroscopy was used in 6 surgeries to locate the base of the enlarged transverse process (6/8); intraoperative neuromonitoring was used in 6 patients (6/8), 3D intraoperative advanced spinal image (O-arm) with neuronavigation was used to localize the base of the pseudojoint to be removed and to check the final bone resection for the last 5 cases (5/8).

OUTCOMES

The average paramedian lower back pain before surgery on the visual analogue scale for pain in the 8 patients was 6.6 (range: 5-8) and reduced to 1.5 (range: 0-3) at the latest follow-up after surgery, while the average pain score of the radicular pain on the right or left side before the surgery was 1.3 (range: 0-6) and reduced to 0.6 (range: 0-7) after the surgery.

LESSONS

The mini-open tubular microsurgical transverse processectomy seems to be potentially safe and effective for the surgical treatment of selected symptomatic patients with Bertolotti's syndrome.

Effect of MRI-Guided Fibrosis Ablation vs Conventional Catheter Ablation on Atrial Arrhythmia Recurrence in Patients With Persistent Atrial Fibrillation: The DECAAF II Randomized Clinical Trial

Importance

Ablation of persistent atrial fibrillation (AF) remains a challenge. Left atrial fibrosis plays an important role in the pathophysiology of AF and has been associated with poor procedural outcomes.

Objective

To investigate the efficacy and adverse events of targeting atrial fibrosis detected on magnetic resonance imaging (MRI) in reducing atrial arrhythmia recurrence in persistent AF.

Design, Setting, and Participants

The Efficacy of Delayed Enhancement-MRI-Guided Fibrosis Ablation vs Conventional Catheter Ablation of Atrial Fibrillation trial was an investigator-initiated, multicenter, randomized clinical trial involving 44 academic and nonacademic centers in 10 countries. A total of 843 patients with symptomatic or asymptomatic persistent AF and undergoing AF ablation were enrolled from July 2016 to January 2020, with follow-up through February 19, 2021.

Interventions

Patients with persistent AF were randomly assigned to pulmonary vein isolation (PVI) plus MRI-guided atrial fibrosis ablation (421 patients) or PVI alone (422 patients). Delayed-enhancement MRI was performed in both groups before the ablation procedure to assess baseline atrial fibrosis and at 3 months postablation to assess for ablation scar.

Main Outcomes and Measures

The primary end point was time to first atrial arrhythmia recurrence after a 90-day blanking period postablation. The primary safety composite outcome was defined by the occurrence of 1 or more of the following events within 30 days postablation: stroke, PV stenosis, bleeding, heart failure, or death.

Results

Among 843 patients who were randomized (mean age 62.7 years; 178 [21.1%] women), 815 (96.9%) completed the 90-day blanking period and contributed to the efficacy analyses. There was no significant difference in atrial arrhythmia recurrence between groups (fibrosis-guided ablation plus PVI patients, 175 [43.0%] vs PVI-only patients, 188 [46.1%]; hazard ratio [HR], 0.95 [95% CI, 0.77-1.17]; P = .63). Patients in the fibrosis-guided ablation plus PVI group experienced a higher rate of safety outcomes (9 [2.2%] vs 0 in PVI group; P = .001). Six patients (1.5%) in the fibrosis-guided ablation plus PVI group had an ischemic stroke compared with none in PVI-only group. Two deaths occurred in the fibrosis-guided ablation plus PVI group, and the first one was possibly related to the procedure.

Conclusions and Relevance

Among patients with persistent AF, MRI-guided fibrosis ablation plus PVI, compared with PVI catheter ablation only, resulted in no significant difference in atrial arrhythmia recurrence. Findings do not support the use of MRI-guided fibrosis ablation for the treatment of persistent AF.

Trial Registration

ClinicalTrials.gov Identifier: NCT02529319.

Fluoroless Ureteroscopy: Experience in More Than 100 Patients

BACKGROUND

Ureteroscopy is becoming the primary treatment for ureteral stones. As a standard of care, ureteroscopy is performed under the supervision of fluoroscopy. Recent advances in endourological technology make the need for fluoroscopy questionable.

OBJECTIVES

To summarize our experience with a no-fluoroscopy technique for selected cases of ureteral stones.

METHODS

Patients were considered suitable for fluoroless ureteroscopy if they had one or two non-impacted stones, in any location in the ureter, 5-10 mm size, with a normal contralateral renal unit and no urinary tract infection. Procedures were performed using rigid scopes, nitinol baskets/forceps for stone retrieval, and Holmium:YAG laser for lithotripsy. Stents were placed per surgeon's decision.

RESULTS

During an 18-month period, 103 patients underwent fluoroless ureteroscopy. In 94 patients stones were removed successfully. In six, the stones were pushed to the kidney and treated successfully on a separate session by shock wave lithotripsy. In three patients no stone was found in the ureter. In five patients, miniature perforations in the ureter were noted and an indwelling double J stent was placed.

CONCLUSIONS

Fluoroless ureteroscopy resulted in a high rate of success. We believe that in selected cases it can be used with minimal adverse events.

Computer-navigated versus conventional total knee arthroplasty: A randomized controlled trial protocol in China

BACKGROUND

The literature lacks studies that confirm whether the improved radiographic alignment that can be achieved with computer-navigated total knee arthroplasty (TKA) improves patients' activities of daily living or the durability of total knee prostheses. Thus, in this protocol, we designed a randomized controlled trial to compare implant alignment, functional scores, and survival of the implant using computer-assisted surgery versus a conventional surgical technique.

METHODS

This prospective, blinded randomized controlled trial was conducted at our single hospital. This study was approved by the ethics committee of Jiaxing Second Hospital. The patient inclusion criteria were age 20 to 80 years' old, a body mass index of ≤35 kg/m, and consented for primary knee arthroplasty performed through a medial parapatellar approach by the senior author. We randomized consented study participants on a 1:1 ratio to 1 of 2 study groups using a computer-generated list of random numbers in varying block sizes. The primary outcome in this study was the Knee Injury and Osteoarthritis Outcome Score. Secondary outcomes were the Knee Society Score, Western Ontario and McMaster Universities Osteoarthritis Index, complications, and range of motion together with alignment and rotational positioning of the implant. Statistical significance was defined as a P value of ≤0.05.

CONCLUSIONS

Authors hypothesized that computer-assisted surgery in primary TKA improves implant alignment, functional scores, and survival of the implant compared to the conventional technique.

Association of Computer-Assisted Virtual Preoperative Planning With Postoperative Mortality and Complications in Older Patients With Intertrochanteric Hip Fracture

IMPORTANCE

The outcomes of surgical treatment in patients with intertrochanteric hip fractures are unsatisfactory. Computer-assisted virtual preoperative planning may provide an opportunity to solve this treatment dilemma. Virtual preoperative planning is a technique based on dynamic 3-dimensional computed tomographic imaging, which allows precise evaluation of fracture details and simulation of reduction of fracture and internal fixation procedures before surgery is performed.

OBJECTIVE

To evaluate the association of computer-assisted virtual preoperative planning with the risk of 90-day all-cause mortality and postoperative complications.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study was conducted from using patient data from a level 1 trauma center database. A total of 1445 patients 65 years and older with intertrochanteric hip fractures between January 1, 2009, and March 31, 2018, were identified and divided into 2 cohorts: 558 patients received computer-assisted virtual preoperative planning (virtual planning group), and 887 patients received conventional preoperative planning (conventional planning group). Of the initial 1445 patients, 224 patients (93 patients in the virtual planning group and 131 patients in the conventional planning group) were excluded, resulting in 1221 patients in the final cohort. Data were analyzed from April 5 to October 5, 2019.

EXPOSURES

Computer-assisted virtual vs conventional surgical preoperative planning.

MAIN OUTCOMES AND MEASURES

Primary outcomes were 90-day all-cause mortality and postoperative complications (including myocardial infarction, heart failure, stroke, kidney failure, and sepsis). Secondary outcomes were 90-day outpatient visits, hospital readmissions, and reoperations.

RESULTS

Among 1221 patients who underwent hip surgery, the mean (SD) age was 73.2 (12.3) years, and 927 patients (75.9%) were women. A total of 465 patients (38.1%) were in the virtual planning group and 756 patients (61.9%) were in the conventional planning group. Among the 814 patients (407 patients in each group) who were matched by propensity score, the virtual planning group had a lower incidence of mortality (37 patients [9.1%] vs 55 patients [13.5%]; hazard ratio [HR], 0.64; 95% CI, 0.41-0.99; P = .04) and postoperative complications (25 patients [6.1%] vs 44 patients [10.8%]; HR, 0.54; 95% CI, 0.32-0.90; P = .02) compared with the conventional planning group. The incidence of outpatient visits was not substantially different in the virtual planning group (1.51 incidents per 30 person-days) compared with the conventional planning group (1.48 incidents per 30 person-days; incidence rate ratio [IRR], 0.90; 95% CI, 0.49-1.68; P = .75). Similar results were observed for the rate of hospital readmissions (0.99 incidents per 30 person-days in the virtual planning group and 1.01 incidents per 30 person-days in the conventional planning group; IRR, 0.91; 95% CI, 0.49-1.67; P = .76). However, the rate of reoperations was lower in the virtual planning group (0.76 incidents per 30 person-days) than in the conventional planning group (0.97 incidents per 30 person-days; IRR, 0.41; 95% CI, 0.22-0.76; P = .01).

CONCLUSIONS AND RELEVANCE

Among older patients with intertrochanteric hip fractures, computer-assisted virtual preoperative planning was associated with decreases in the risks of all-cause 90-day mortality, postoperative complications, and reoperations compared with conventional preoperative planning.

A retrospective comparison of the conventional versus three-dimensional printed model-assisted surgery in the treatment of acetabular fractures

OBJECTIVE

The aim of this study was to compare the clinical and radiological outcomes of the conventional versus individualized three-dimensional (3D) printing model-assisted pre-contoured plate fixation in the treatment of patients with acetabular fractures.

METHODS

The data from 18 consecutive patients who underwent surgery for the acetabular fractures were retrospectively analyzed. The patients were divided into two groups (9 in each): conventional and 3D printed model-assisted. The groups were then compared in terms of the duration of surgery, time of instrumentation, time of intraoperative fluoroscopy, and volume of blood loss. The quality of the fracture reduction was also evaluated postoperatively by radiography and computed tomography in both the groups. The quality of the fracture reduction was defined as good (<2 mm) or fair (>2 mm) based on the amount of displacement in the acetabulum.

RESULTS

The conventional group included 9 patients (9 males; mean age=41.7 years; age range=16-70) with a mean follow-up of 11.9 months (range=8-15); the 3D printed model-assisted group consisted of 9 patients (9 males; mean age=46.2 years; age range=30-66) with a mean follow-up of 10.33 months (range=7-17). The average duration of surgery, mean time of instrumentation, time of intraoperative fluoroscopy, and mean volume of blood loss were 180.5±9 minutes, 36.2±3.6 minutes, 6±1 times, and 403.3±52.7 mL in the 3D printed model-assisted group, and 220±15.6 minutes, 57.4±10.65 minutes, 10.4±2.2 times, and 606.6±52.7 mL in the conventional group, respectively. Procedurally, the average duration of surgery, mean time of instrumentation, and mean time of fluoroscopy were significantly shorter, and the mean volume of blood loss was significantly lower in the 3D printed model-assisted group (p<0.05). The quality of the fracture reduction was good in 7 patients (78%) in the conventional group and 8 patients (89%) in the 3D printed model-assisted group.

CONCLUSION

As compared with the conventional surgery, the 3D printing model-assisted pre-contoured plate fixation technique can improve the clinical and radiological outcomes of the acetabular fractures, with shorter surgery, instrumentation, intraoperative fluoroscopy times, and blood loss.

LEVEL OF EVIDENCE

Level III, Therapeutic study.

Association of Image-Guided Navigation With Complete Resection Rate in Patients With Locally Advanced Primary and Recurrent Rectal Cancer: A Nonrandomized Controlled Trial

IMPORTANCE

The percentage of tumor-positive surgical resection margin rates in patients treated for locally advanced primary or recurrent rectal cancer is high. Image-guided navigation may improve complete resection rates.

OBJECTIVE

To ascertain whether image-guided navigation during rectal cancer resection improves complete resection rates compared with surgical procedures without navigation.

DESIGN, SETTING, AND PARTICIPANTS

This prospective single-center nonrandomized controlled trial was conducted at the Netherlands Cancer Institute-Antoni van Leeuwenhoek in Amsterdam, the Netherlands. The prospective or navigation cohort included adult patients with locally advanced primary or recurrent rectal cancer who underwent resection with image-guided navigation between February 1, 2016, and September 30, 2019, at the tertiary referral hospital. Clinical results of this cohort were compared with results of the historical cohort, which was composed of adult patients who received rectal cancer resection without image-guided navigation between January 1, 2009, and December 31, 2015.

INTERVENTION

Rectal cancer resection with image-guided navigation.

MAIN OUTCOMES AND MEASURES

The primary end point was the complete resection rate, measured by the amount of tumor-negative resection margin rates. Secondary outcomes were safety and usability of the system. Safety was evaluated by the number of navigation system-associated surgical adverse events. Usability was assessed from responses to a questionnaire completed by the participating surgeons after each procedure.

RESULTS

In total, 33 patients with locally advanced or recurrent rectal cancer were included (23 men [69.7%]; median [interquartile range] age at start of treatment, 61 [55.0-69.0] years). With image-guided navigation, a radical resection (R0) was achieved in 13 of 14 patients (92.9%; 95% CI, 66.1%-99.8%) after primary resection of locally advanced tumors and in 15 of 19 patients (78.9%; 95% CI, 54.4%-94.0%) after resection of recurrent rectal cancer. No navigation system-associated complications occurred before or during surgical procedures. In the historical cohort, 142 patients who underwent resection without image-guided navigation were included (95 men [66.9%]; median [interquartile range] age at start of treatment, 64 [55.0-70.0] years). In these patients, an R0 resection was accomplished in 85 of 101 patients (84.2%) with locally advanced rectal cancer and in 20 of 41 patients (48.8%) with recurrent rectal cancer. A significant difference was found between the navigation and historical cohorts after recurrent rectal cancer resection (21.1% vs 51.2%; P = .047). For locally advanced primary tumor resection, the difference was not significant (7.1% vs 15.8%; P = .69). Surgeons stated in completed questionnaires that the navigation system improved decisiveness and helped with tumor localization.

CONCLUSIONS AND RELEVANCE

Findings of this study suggest that image-guided navigation used during rectal cancer resection is safe and intuitive and may improve tumor-free resection margin rates in recurrent rectal cancer.

TRIAL REGISTRATION

Netherlands Trial Register Identifier: NTR7184.

Computerized navigation for total hip arthroplasty is associated with lower complications and ninety-day readmissions: a nationwide linked analysis

INTRODUCTION

The objective was to evaluate if the use of CA-THA was associated with lower complications in the first 90 days following THA compared with conventional THA.

METHODS

The Nationwide Readmission Database (NRD) was queried to identify patients who underwent THA between 2012 and 2014. The primary outcome was arthroplasty-related complications within the first 90 days following THA. Multivariate models predicting the risk of complications, readmission, and revision-related readmission within 90 days of discharge were created.

RESULTS

A total of 309,252 patients with a minimum 90-day follow-up following elective primary THA were identified. After controlling for age, sex, comorbidities, indication, income, and type of insurance, the use of CA during THA resulted in a 12% reduced odds of 90-day complications (OR 0.88, 95% CI 0.77-0.99, p = 0.04).

DISCUSSION

The use of CA-THA resulted in lower 90-day complication rates and readmission rates compared with traditional THA after controlling for confounding variables. There was no significant difference in the rates of revision surgery between the groups within the first 90 days.

Virtual-Reality Guided Versus Fluoroscopy-Guided Transseptal Puncture in a Cardiac Phantom

OBJECTIVES

We compared virtual-reality guided versus fluoroscopy-guided transseptal puncture by novice and experienced operators in a cardiac phantom. Outcome measures included accuracy, time, transseptal path distance, and a survey of the operator experience.

METHODS

A transseptal simulator was created using a Plexiglas case and a 3D-printed cardiac phantom with a replaceable fossa ovalis, a customized support, and an electromagnetic tracking system. A precisely registered virtual-reality rendering was constructed. To display the transseptal instruments in virtual reality, we attached electromagnetic sensors to standard transseptal instruments, including the needle, dilator, and sheath. Each subject completed 6 simulated transseptal punctures (3 fluoroscopy-guided and 3 virtual-reality guided). We measured the distance traversed by the transseptal needle, accuracy, and time for each simulated transseptal puncture. Operators were then surveyed regarding their experience.

RESULTS

A total of 8 subjects (6 faculty, 2 fellows) completed the trial. We found that virtual-reality guidance resulted in significantly more accurate puncture site selection and, subjectively, was more intuitive for the operator, particularly for novices. None of the participants experienced negative symptoms in virtual reality that required cessation of the procedure.

CONCLUSIONS

Virtual reality compared with fluoroscopic guidance for transseptal puncture shows considerable promise, particularly for novice trainees, where it could lessen the learning curve. Current barriers to widespread implementation are discussed.

The European Robotic Spinal Instrumentation (EUROSPIN) study: protocol for a multicentre prospective observational study of pedicle screw revision surgery after robot-guided, navigated and freehand thoracolumbar spinal fusion

INTRODUCTION

Robotic guidance (RG) and computer-assisted navigation (NV) have seen increased adoption in instrumented spine surgery over the last decade. Although there exists some evidence that these techniques increase radiological pedicle screw accuracy compared with conventional freehand (FH) surgery, this may not directly translate to any tangible clinical benefits, especially considering the relatively high inherent costs. As a non-randomised, expertise-based study, the European Robotic Spinal Instrumentation Study aims to create prospective multicentre evidence on the potential comparative clinical benefits of RG, NV and FH in a real-world setting.

METHODS AND ANALYSIS

Patients are allocated in a non-randomised, non-blinded fashion to the RG, NV or FH arms. Adult patients that are to undergo thoracolumbar pedicle screw instrumentation for degenerative pathologies, infections, vertebral tumours or fractures are considered for inclusion. Deformity correction and surgery at more than five levels represent exclusion criteria. Follow-up takes place at 6 weeks, as well as 12 and 24 months. The primary endpoint is defined as the time to revision surgery for a malpositioned or loosened pedicle screw within the first postoperative year. Secondary endpoints include patient-reported back and leg pain, as well as Oswestry Disability Index and EuroQOL 5-dimension questionnaires. Use of analgesic medication and work status are recorded. The primary analysis, conducted on the 12-month data, is carried out according to the intention-to-treat principle. The primary endpoint is analysed using crude and adjusted Cox proportional hazards models. Patient-reported outcomes are analysed using baseline-adjusted linear mixed models. The study is monitored according to a prespecified monitoring plan.

ETHICS AND DISSEMINATION

The study protocol is approved by the appropriate national and local authorities. Written informed consent is obtained from all participants. The final results will be published in an international peer-reviewed journal.

TRIAL REGISTRATION NUMBER

Clinical Trials.gov registry NCT03398915; Pre-results, recruiting stage.

Evaluation of surgeon and patient radiation exposure by imaging technology in patients undergoing thoracolumbar fusion: systematic review of the literature

BACKGROUND CONTEXT

Minimally invasive spine techniques are becoming increasingly popular owing to their ability to reduce operative morbidity and recovery times. The downside to these new procedures is their need for intraoperative radiation guidance.

PURPOSE

To establish which technologies provide the lowest radiation exposure to both patient and surgeon.

STUDY DESIGN/SETTING

Systematic review OUTCOME MEASURES: Average intraoperative radiation exposure (in mSv per screw placed) to surgeon and patient. Average fluoroscopy time per screw placed.

METHODS

We reviewed the available English medical literature to identify all articles reporting patient and/or surgeon radiation exposure in patients undergoing image-guided thoracolumbar instrumentation. Quantitative meta-analysis was performed for studies providing radiation exposure or fluoroscopy use per screw placed to determine which navigation modality was associated with the lowest intraoperative radiation exposure. Values on meta-analysis were reported as mean ± standard deviation.

RESULTS

We identified 4956 unique articles, of which 85 met inclusion/exclusion criteria. Forty-one articles were included in the meta-analysis. Patient radiation exposure per screw placed for each modality was: conventional fluoroscopy without navigation (0.26±0.38 mSv), conventional fluoroscopy with pre-operative CT-based navigation (0.027±0.010 mSv), intraoperative CT-based navigation (1.20±0.91 mSv), and robot-assisted instrumentation (0.04±0.30 mSv). Values for fluoroscopy used per screw were: conventional fluoroscopy without navigation (11.1±9.0 seconds), conventional fluoroscopy with navigation (7.20±3.93 s), 3D fluoroscopy (16.2±9.6 s), intraoperative CT-based navigation (19.96±17.09 s), and robot-assistance (20.07±17.22 s). Surgeon dose per screw: conventional fluoroscopy without navigation (6.0±7.9 × 10^-3 mSv), conventional fluoroscopy with navigation (1.8±2.5 × 10^-3 mSv), 3D Fluoroscopy (0.3±1.9 × 10^-3 mSv), intraoperative CT-based navigation (0±0 mSv), and robot-assisted instrumentation (2.0±4.0 × 10^-3 mSv).

CONCLUSION

All image guidance modalities are associated with surgeon radiation exposures well below current safety limits. Intraoperative CT-based (iCT) navigation produces the lowest radiation exposure to surgeon albeit at the cost of increased radiation exposure to the patient relative to conventional fluoroscopy-based methods.

Three-dimensional navigation (O-arm) versus fluoroscopy in the treatment of thoracic spinal stenosis with ultrasonic bone curette: A retrospective comparative study

Three-dimensional intraoperative navigation (O-arm) has been used for many years in spinal surgeries and has significantly improved its precision and safety. This retrospective study compared the efficacy and safety of spinal cord decompression surgeries performed with O-arm navigation and fluoroscopy. The clinical data of 56 patients with thoracic spinal stenosis treated from March 2015 to April 2017 were retrospectively analyzed. Spinal decompression was performed with O-arm navigation and ultrasonic bone curette in 29 patients, and with ultrasonic bone curette and fluoroscopy in 27 patients. Patients were followed-up at postoperative 1 month, 3 months, and the last clinic visit. The neurologic functions were assessed using the Japanese Orthopaedic Association (JOA) Back Pain Evaluation Questionnaire. The accuracy of screw placement was examined using three-dimensional computed tomography (CT) on postoperative day 5. There was no significant difference in the incidences of intraoperative dural tear, nerve root injury, and spinal cord injury between the two groups. The two groups showed no significant difference in postoperative JOA scores (P > .05). The O-arm navigation group had significantly higher screw placement accuracy than the fluoroscopy group (P < .05). O-arm navigation is superior to fluoroscopy in the treatment of thoracic spinal stenosis with ultrasonic bone curette in terms of screw placement accuracy. However, the two surgical modes have similar rates of intraoperative complications and postoperative neurologic functions.

Application of indocyanine green fluorescence endoscopic system in transsphenoidal surgery for pituitary tumors

BACKGROUND

For the precise removal of pituitary tumors, preserving the surrounding normal structures, we need real-time intraoperative information on tumor location, margins, and surrounding structures. The aim of this study was to evaluate the benefits of a new intraoperative real-time imaging modality using indocyanine green (ICG) fluorescence through an endoscopic system during transsphenoidal surgery (TSS) for pituitary tumors.

METHODS

Between August 2013 and October 2014, 20 patients with pituitary and parasellar region tumors underwent TSS using the ICG fluorescence endoscopic system. We used a peripheral vein bolus dose of 6.25 mg/injection of ICG, started with a time counter, and examined how each tissue type increased and decreased in fluorescence through time.

RESULTS

A total of 33 investigations were performed for 20 patients: 9 had growth hormone secreting adenomas, 6 non-functioning pituitary adenomas, 3 Rathke's cleft cysts, 1 meningioma, and 1 pituicytoma. After the injection of ICG, the intensity of fluorescence of tumor and normal tissues under near-infrared light showed clear differences. We could differentiate tumor margins from adjacent normal tissues and define clearly the surrounding normal structures using the different fluorescent intensities time changes and tissue-specific fluorescence patterns.

CONCLUSIONS

The ICG endoscopic system is simple, user-friendly, quick, cost-effective, and reliable. The method offered real-time information during TSS to delimit pituitary and parasellar region tumor tissue from surrounding normal structures. This method can contribute to the improvement of total removal rates of tumors, reduction of complications after TSS, saving surgical time, and preserving endocrinological functions.

Percutaneous fluoroscopically-guided transcervical retrograde access facilitates successful thoracic duct embolization after failed antegrade transabdominal access

The purpose of this study was to demonstrate the feasibility of percutaneous fluoroscopically-guided transcervical retrograde access into the thoracic duct following unsuccessful transabdominal cisterna chyli cannulation to perform thoracic duct embolization for the treatment of chylothorax. Five patients, including three (60%) women and two (40%) men, with median age of 62 years, underwent percutaneous transcervical thoracic duct access and embolization after failed transabdominal cisterna chyli cannulation for the treatment of chylothorax. In all patients, fluoroscopically-guided percutaneous transcervical retrograde access into the distal thoracic duct was achieved using a 21-gauge needle and an 0.018-inch wire. Following advancement of a microcatheter, retrograde lymphangiography was performed to identify the location of thoracic duct injury. A combination of 2:1 ethiodized oil to cyanoacrylate mixtures, platinum microcoils, or stent-grafts were used to treat the chylous leaks. Technical successes, procedure durations, fluoroscopy times, blood losses, immediate adverse events, clinical successes, and follow-up durations were recorded. Technical success was defined as cannulation of the distal thoracic duct using a transcervical approach followed by treatment of the thoracic duct injury. Adverse events were classified according to the Society of Interventional Radiology guidelines. Clinical success was defined as resolution of the presenting chylothorax. Percutaneous transcervical retrograde thoracic duct access and treatment was technically successful in all patients (n=5). Median procedure duration was 173 minutes (range: 136-347 minutes) with a median fluoroscopy time of 94.7 minutes (range: 47-125 minutes). Median blood loss was 10 mL (range: 5-20 mL). No minor or major adverse occurred. Clinical success was achieved in all patients (n=5). Median follow-up was 372 days (range: 67-661 days). Percutaneous fluoroscopically- guided transcervical retrograde thoracic duct access is an effective and safe method to perform thoracic duct embolization following unsuccessful transabdominal cisterna chyli cannulation for the treatment of chylothorax.

Use of intraoperative intracavitary (direct-contact) ultrasound for resection control in transsphenoidal surgery for pituitary tumors: evaluation of a microsurgical series

BACKGROUND

Perisellar infiltration may be responsible for incomplete removal of pituitary tumors. Since intraoperative visualization of parasellar structures is difficult during transsphenoidal surgery, we are describing the use of intraoperative direct contact ultrasound (IOUS).

METHODS

Within 5 years, in 113 transsphenoidal operations (58 male, 55 female, age 14-81 years, 110 pituitary adenomas (mean diameter 26.6 mm, 69 non-secreting adenomas, 41 secreting adenomas), and 1 of each Rathke's cleft cyst, craniopharyngioma, and xanthogranuloma), IOUS was applied. After wide opening of the sellar floor and removal of the intrasellar tumor portions, a commercially available side fire ultrasound probe is introduced, and in direct contact to the sellar envelope, the perisellar space is scanned perpendicular to the axis of the working channel. We compared the results of IOUS to postoperative MRI after 3-6 months.

RESULTS

Identification of the intracavernous ICA, the anterior optic pathway, and the ACA, was possible, it was safe to operate close to them. In 65 operations (58%), further resection of tumor remnants was performed after IOUS. In this selected series, complete resection of tumors (stated by postoperative MRI after 3-6 months) was achieved in 75 operations (66%) and remission was achieved in 18 operations of secreting adenomas (44%). Compared to MRI after 3 to 6 months, the sensitivity of IOUS was 0.568 and the specificity was 0.907. No complications related to IOUS were seen.

CONCLUSIONS

Visualization of the perisellar compartments by IOUS is easy and fast to perform. It allows the surgeon to identify resectable tumor remnants intraoperatively, which otherwise could be missed.

Practical Assessment of Radiation Exposure in Spine Surgery

BACKGROUND

Fluoroscopy use in spine surgery is increasing owing to the increasing popularity of minimally invasive techniques. The effectiveness and safe distance for protective barriers might have been commonly misrepresented. The present study evaluated x-ray propagation and the efficacy of protective barriers in the setting of spine surgery.

METHODS

A high-accuracy radiation dosimeter was used to measure x-ray exposure in an experimental setting replicating the spine surgery setup. Radiation was measured at different angles and distances from the x-ray source with and without protective barriers such as lead gowns and glass.

RESULTS

The radiation values return to baseline at 14 ft (4.3 m) in front of the x-ray source and 8 ft (2.4 m) behind it. Protective barriers with a 0.5-mm lead-equivalence reduced radiation exposure to baseline at 6 ft (1.8 m) and were 20% effective at 2 ft (0.6 m) from the emitter.

CONCLUSION

Spine surgeons who wear lead gowns during fluoroscopy could still be exposed to <80% of the radiation produced. Safe distances from fluoroscopy machines might be much farther than commonly believed. Alternatives to reduce the use of fluoroscopy for intraoperative imaging should be explored.

Prognostic outcome and complications of sentinel lymph node navigation surgery for early-stage cervical cancer

BACKGROUND

To evaluate the prognostic outcome and surgical complications in patients with early-stage cervical cancer who underwent sentinel node navigation surgery (SNNS) for hysterectomy or trachelectomy.

METHODS

A total of 139 patients who underwent SNNS using ^99mTc phytate between 2009 and 2015 were evaluated. No further lymph node dissection was performed when intraoperative analysis of the sentinel lymph nodes (SLNs) was negative for metastasis. We compared the surgical complications between the SNNS group and 67 matched patients who underwent pelvic lymph node dissection (PLND) after SLN mapping between 2003 and 2008. We also examined the clinical outcomes in the SNNS group.

RESULTS

The mean number of detected SLNs was 2.5 per patient. Fourteen of the 139 patients in the SNNS group underwent PLND based on the intraoperative SLN results. The amount of blood loss, the operative time, and the number of perioperative complications were significantly less in the SNNS group than in the matched PLND group. There was no recurrence during a follow-up period ranging from 2 to 88 months (median 40 months) in the SNNS group.

CONCLUSIONS

Using SNNS for early-stage cervical cancer is safe and effective and does not increase the recurrence rate. A future multicenter trial is warranted.

Computer-assisted, minimally invasive transforaminal lumbar interbody fusion: One surgeon's learning curve A STROBE-compliant article

Minimally invasive (MI) transforaminal lumbar interbody fusion (TLIF) is a challenging technique with a long learning curve. We combined computer-assisted navigation and MI TLIF (CAMISS TLIF) to treat lumbar degenerative disease. This study aimed to evaluate the learning curve associated with computer-assisted navigation MI spine surgery (CAMISS) and TLIF for the surgical treatment of lumbar degenerative disease. Seventy four consecutive patients with lumbar degenerative disease underwent CAMISS TLIF between March 2011 and May 2015; all surgeries were performed by a single surgeon. According to the plateau of the asymptote, the initial 25 patients constituted the early group and the remaining patients comprised the latter group. The clinical evaluation data included operative times, anesthesia times, intraoperative blood losses, days until ambulation, postoperative hospital stays, visual analog scale (VAS) leg and back pain scores, Oswestry disability index (ODI) values, Macnab outcome scale scores, complications, radiological outcomes, and rates of conversion to open surgery. The complexity of the cases increased over the series, but the complication rate decreased (12.00%-6.12%). There were significant differences between the early and late groups with respect to the average surgical times and durations of anesthesia, but no differences in intraoperative blood losses, days until ambulation, postoperative hospital stays, complication rate, VAS, ODI, Macnab outcome scale scores, or solid fusion rates. There was no need for conversion to open procedures in either group. Our study showed that a plateau asymptote for CAMISS TLIF was reached after 25 operations. The later patients experienced shorter operative times and anesthesia durations.

Surgical navigation improves reductions accuracy of unilateral complicated zygomaticomaxillary complex fractures: a randomized controlled trial

Accurate reduction is the key to successful treatment of bone fractures. Complicated zygomaticomaxillary complex fracture, known as one of the most challenging facial bone fractures, is often hard to achieve an accurate reduction, thus leading to facial deformity. In this study, twenty patients with unilateral complicated zygomaticomaxillary complex fractures were included and randomly divided into experimental and control groups, which is with and without the aid of surgical navigation, respectively. The pre- and postoperative imaging data were collected and then analysed using Geomagic Studio 11 software and Brainlab iPlan CMF 3.0. A more precise reduction was showed in the experimental group according to the measurement results of both software programmes than in the control group. In conclusion, surgical navigation showed great value in performing accurate reductions of complicated zygomaticomaxillary complex fractures and restoring facial contour.

Fontan Surgical Planning: Previous Accomplishments, Current Challenges, and Future Directions

The ultimate goal of Fontan surgical planning is to provide additional insights into the clinical decision-making process. In its current state, surgical planning offers an accurate hemodynamic assessment of the pre-operative condition, provides anatomical constraints for potential surgical options, and produces decent post-operative predictions if boundary conditions are similar enough between the pre-operative and post-operative states. Moving forward, validation with post-operative data is a necessary step in order to assess the accuracy of surgical planning and determine which methodological improvements are needed. Future efforts to automate the surgical planning process will reduce the individual expertise needed and encourage use in the clinic by clinicians. As post-operative physiologic predictions improve, Fontan surgical planning will become an more effective tool to accurately model patient-specific hemodynamics.

Improved accuracy of screw implantation could decrease the incidence of post-operative hydrothorax? O-arm navigation vs. free-hand in thoracic spinal deformity correction surgery

PURPOSE

The purpose of this study was to analyze the occurrence of PE after intra-operative O-arm navigation-assisted surgery and determine whether the post-operative PE incidence could be decreased by using O-arm navigation as compared to conventional free-hand technique.

METHODS

A cohort of 27 patients with spinal deformity who were operated upon with an O-arm navigated system (group A) between 2013 and 2016 were enrolled in the study. A total of 27 curve-matched patients treated by conventional free-hand technique were included as the control group (group B). Whole spine posterior-anterior and lateral radiographs, and CT scans were taken pre and post-operation. Radiologic parameters and volume of PE were measured and compared between the two groups.

RESULTS

There were no significant differences in age, Cobb angle, and sagittal contour between the two groups pre-operatively. The mean total volume of post-operative PE was significantly larger in the free-hand group (p < 0.001). In the O-arm group, 59 malpositioned screws were identified in 22 patients. In the free-hand group, 88 malpositioned screws were found among 26 patients. The screw perforation rate was higher in the free-hand group than in the O-arm group (p = 0.007). In the O-arm group, the mean volume of PE was significantly larger among patients with malpositioned screws than those without malpositioned screws (p < 0.001), as well as in the free-hand group.

CONCLUSION

The volume of PE after correction surgery can be significantly decreased by application of O-arm navigation system as compared to conventional free-hand technique. We ascribed the improvement to the accuracy of screw implantation navigated by O-arm.

Image-guided Ommaya reservoir insertion for intraventricular chemotherapy: a retrospective series

BACKGROUND

Ayub Ommaya proposed a surgical technique for subcutaneous reservoir and pump placement in 1963 to allow access to intraventricular cerebrospinal fluid (CSF). Currently, the most common indication for Ommaya reservoir insertion (ORI) in adults is for patients with hematologic or leptomeningeal disorders requiring repeated injection of chemotherapy into the CSF space. Historically, the intraventricular catheter has been inserted blindly based on anatomical landmarks. The purpose of this study was to examine short-term complication rates with ORI with image guidance (IG) and without image guidance (non-IG).

METHODS

We retrospectively evaluated all operative cases of ORI from 2000 to 2014 by the senior author. Patient demographic data, surgical outcomes, and peri-operative complications were collected. Accurate placement and early (30-day) morbidity or mortality were considered primary outcomes.

RESULTS

Fifty-five consecutive patients underwent ORI by the senior author over the study period (43.5 ± 16.6 years; 40.0% female). Indications for placement included acute lymphoblastic leukemia, diffuse large B-cell lymphoma, and leptomeningeal carcinomatosis. There were seven (12.7%) total complications: three (37.5%) with no-IG versus four (8.5%) with IG. Catheter malpositions were significantly higher in the non-IG group at 37.5% compared to 2.1%. Catheters were also more likely to require multiple passes with non-IG at 25% compare to 0% with IG. There were no early infections in either group.

CONCLUSIONS

We demonstrate improved accuracy and decreased complications using an image-guided approach compared with a traditional approach. Our results support routine use of intra-operative image guidance for proximal catheter insertion in elective ORI for intraventricular chemotherapy.

Impact of the Use of Intravascular Imaging on Patients Who Underwent Orbital Atherectomy

OBJECTIVES

We assessed the impact of intravascular ultrasound (IVUS)/optical coherence tomography (OCT) on outcomes of patients who underwent orbital atherectomy.

BACKGROUND

Intravascular imaging provides enhanced lesion morphology assessment and optimization of percutaneous coronary intervention (PCI) outcomes. Severe coronary artery calcification increases the complexity of PCI and is associated with worse clinical outcomes. Orbital atherectomy modifies calcified plaque, facilitating stent delivery and optimizing stent expansion. The impact of IVUS/OCT on clinical outcomes after orbital atherectomy is unknown.

METHODS

Of the 458 consecutive real-world patients in our retrospective multicenter registry, a total of 138 patients (30.1%) underwent orbital atherectomy with IVUS/OCT. The primary safety endpoint was the rate of 30-day major adverse cardiac and cerebrovascular events, comprised of death, myocardial infarction (MI), target-vessel revascularization (TVR), and stroke.

RESULTS

The IVUS/OCT group and no-imaging group had similar rates of the primary endpoint (1.5% vs 2.5%; P=.48) as well as death (1.5% vs 1.3%; P=.86), MI (1.5% vs 0.9%; P=.63), TVR (0% vs 0%; P=NS), and stroke (0% vs 0.3%; P=.51). The 30-day stent thrombosis rates were low in both groups (0.7% vs 0.9%; P=.82). Emergent coronary artery bypass graft surgery was uncommonly performed in both groups (0.0% vs 0.9%; P=.25).

CONCLUSION

Orbital atherectomy guided by intravascular imaging is feasible and safe. A large prospective randomized trial is needed to determine the clinical benefit of IVUS/OCT during PCI with orbital atherectomy.

2017 Chitranjan S. Ranawat Award: Does Computer Navigation in Knee Arthroplasty Improve Functional Outcomes in Young Patients? A Randomized Study

BACKGROUND

Proponents of computer-assisted TKA suggest that better alignment of the TKAs will lead to improved long-term patient functional outcome and survivorship of the implants. However, there is little evidence about whether the improved position and alignment of the knee components obtained using computer navigation improve patient function and the longevity of the TKA.

QUESTIONS/PURPOSES

The purpose of this study was to determine whether (1) clinical results; (2) radiographic and CT scan results; and (3) the survival rate of TKA components would be better in patients having computer-assisted TKA than results of patients having TKA without computer-assisted TKA. In addition, we determined whether (4) complication rates would be less in the patients with computer-assisted TKA than those in patients with conventional TKA.

METHODS

We performed a randomized trial between October 2000 and October 2002 in patients undergoing same-day bilateral TKA; in this trial, one knee was operated on using navigation, and the other knee was operated on without navigation. All 296 patients who underwent same-day bilateral TKA during that period were enrolled. Of those, 282 patients (95%) were accounted for at a mean of 15 years (range, 14-16 years). A total of 79% (223 of 282) were women and the mean age of the patients at the time of index arthroplasty was 59 ± 7 years (range, 48-64 years). Knee Society knee score, WOMAC score, and UCLA activity score were obtained preoperatively and at latest followup. Radiographic measurements were performed including femorotibial angle, position of femoral and tibial components, level of joint line, and posterior condylar offset. Aseptic loosening was defined as a complete radiolucent line > 1 mm in width around any component or migration of any component. Assessors and patients were blind to treatment assignment.

RESULTS

The Knee Society knee (92 ± 8 versus 93 ± 7 points; 95% confidence interval [CI], 92-98; p = 0.461) and function scores (80 ± 11 versus 80 ± 11 points; 95% CI, 73-87; p = 1.000), WOMAC score (14 ± 7 versus 15 ± 8 points; 95% CI, 14-18; p = 0.991), range of knee motion (128° ± 9° versus 127° ± 10°; 95% CI, 100-140; p = 0.780), and UCLA patient activity score (6 versus 6 points; 95% CI, 4-8; p = 1.000) were not different between the two groups at 15 years followup. There were no differences in any radiographic parameters of alignment (on radiography or CT scan) between the two groups. The frequency of aseptic loosening was not different between the two groups (p = 0.918). Kaplan-Meier survivorship of the TKA components was 99% in both groups (95% CI, 93-100) at 15 years as the endpoint of revision or aseptic loosening (p = 0.982). Anterior femoral notching was observed in 11 knees (4%) in the computer-assisted TKA group and none in the conventional TKA group (p = 0.046).

CONCLUSIONS

In this randomized trial, with data presented at a minimum of 14 years of followup, we found no benefit to computer navigation in TKA in terms of pain, function, or survivorship. Unless another study at long-term followup identifies an advantage to survivorship, pain, and function, we do not recommend the widespread use of computer navigation in TKA because of its risks (in this series, we observed femoral notching; others have observed pin site fractures) and attendant costs.

LEVEL OF EVIDENCE

Level I, therapeutic study.

[Long-Term Results of Computer-Navigated Total Knee Arthroplasties Performed by Low-Volume and Less Experienced Surgeon]

PURPOSE OF THE STUDY The study aims to evaluate the long-term results of computer-navigated total knee arthroplasties performed by less experienced surgeon performing a small number of procedures per year. MATERIAL AND METHODS In the prospective randomised study functional and radiological results, rate of revision and probability of clinical and radiological survival were compared in 30 computer-navigated (in 28 patients: 19 women, 9 men, with the mean age of 66.9 years) and 31 conventionally implanted (in 30 patients: 27 women, 3 men, with the mean age of 66.5 years) cemented total knee replacements without patellar resurfacing. The group was composed of patients who underwent surgery performed by the same surgeon who at the time of enrolment of patient in the study had no previous experience with the total knee replacement surgery and performed up to 30 such procedures annually. The mean follow-up of patients was 11 years. RESULTS No statistically significant differences were detected regarding the mean age, sex, body mass index and etiology of osteoarthritis of the operated knee. The mean duration of computer-navigated surgeries (101±14.1; 80-140 min) was considerably longer than the duration of conventional joint replacements (94±8.2; 80-100 min; p = 0.01). When evaluating the radiological results, a statistically significant difference was found between the groups only with respect to the mean value of dorsal inclination of the tibial component (88.2˚±2.1 vs 86.2˚±3, p = 0.02). The mean values of other monitored angles did not show any significant differences. The number of correct implants (with a deviation of 3 degrees from the target values) was statistically significantly higher in the group of computer-navigated joint replacement surgeries in all the monitored parameters (aFT: 87% vs. 67%, p = 0.04; α: 87% vs. 71%, p = 0.04; β: 87% vs. 65%, p = 0.03; γ: 93% vs. 74%, p = 0.02; δ: 90% vs. 77%, p = 0.04). Radiologic signs of unstable fixation were detected in 2 cases of computer-navigated joint replacement surgeries and in 7 cases of conventional replacements. Cumulative probability of radiologic survival at 10 years reached 93% in the compute-navigated surgery and 77.4% (p = 0.047) in the group with conventional procedure. In total, 4 revision surgeries with a reimplantation of at least one prosthetic component were reported. All the cases came from the conventional implantation group due to aseptic loosening of the endoprosthesis. In the computer-navigated group, one revision was performed for patellar pain, without replacing or adding any endoprosthetic component. The probability of clinical survival in computer-navigated replacements after 10 years was 100%, in conventional total knee replacements it was 87% (p = 0.04). The cumulative total endoprosthesis revision rate in the computer-navigated group was 3.3%, whereas in the group with conventional total knee replacements it was 12.9% (p = 0.04). The clinical assessment based on the WOMAC and Knee Society Scores showed no statistically significant differences. DISCUSSION The most common cause of the failure of total knee arthroplasties is the malposition of implants which results in early aseptic loosening. The radiologically correct position of knee endoprosthesis is seen in 80% of standard replacement surgeries performed by experienced surgeons. The potential error rate can even increase if the arthroplasties are performed by less experienced orthopaedic surgeons. The computer-navigated total knee replacement was introduced to make the position of implants more accurate. However, the question remains unanswered if more accurate positioning of the implants achieved with computer navigation decrease the revision rate and extend the long-term survival of knee endoprostheses. CONCLUSIONS Kinematic computer navigation allowed a less experienced and low-volume orthopaedic surgeon to make the implantation of endoprostheses more accurate, to decrease the total revision rate, and thus to ensure a higher probability of long-term survival of total knee arthroplasties. Key words:computer navigation, total replacement, knee joint, long-term outcomes, low-volume surgeon, less experienced surgeon.

Scaphoid screw placement under minimal radiation exposure

BACKGROUND

Percutaneous scaphoid fixation through either a volar or dorsal approach has the advantage of minor soft tissue damage compared with ORIF, and faster fracture union compared with conservative treatment. However, this technique demands highly intraoperative reliance on X-ray control, including increased radiation exposure and all associated side effects.

PURPOSE

To test the possibility and efficacy of volar percutaneous scaphoid screw placement under minimalradiation exposure.

METHODS

The sample included 20 hands (seven left, 13 right) from human adult cadavers. For this study, the utilised wrists were assumed to have non-displaced scaphoid fractures. Using a percutaneous approach, a 2-mm Kirschner wire (K-wire) was advanced to the distal pole of the scaphoid and placed in a 45° horizontal and vertical angle under monitoring with the C-arm. The K-wire was inserted blindly alongside the estimated length of the scaphoid. Following K-wire insertion, four X-rays were taken to depict K-wire positioning and to assess positioning alongside the axis of the scaphoid and K-wire protrusion. The rating scale comprised 1 (good), 2 (moderate) or 3 (poor).

RESULTS

All tested radiographic views were evaluated with a median of 2 points (moderate position) regardingplacement alongside the scaphoid axis.

CONCLUSION

Our results indicate that percutaneous scaphoid fixation with the guide wire placed in a 45° horizontal and vertical angle enables primary moderate positioning, which may lead to quicker adjustment to the ideal position and a decrease of radiation exposure.

Percutaneous pedicle screw placement under single dimensional fluoroscopy with a designed pedicle finder-a technical note and case series

BACKGROUND CONTEXT

Minimally invasive spine surgery has become increasingly popular in clinical practice, and it offers patients the potential benefits of reduced blood loss, wound pain, and infection risk, and it also diminishes the loss of working time and length of hospital stay. However, surgeons require more intraoperative fluoroscopy and ionizing radiation exposure during minimally invasive spine surgery for localization, especially for guidance in instrumentation placement. In addition, computer navigation is not accessible in some facility-limited institutions.

PURPOSE

This study aimed to demonstrate a method for percutaneous screws placement using only the anterior-posterior (AP) trajectory of intraoperative fluoroscopy.

STUDY DESIGN

A technical report (a retrospective and prospective case series) was carried out.

PATIENT SAMPLE

Patients who received posterior fixation with percutaneous pedicle screws for thoracolumbar degenerative disease or trauma comprised the patient sample.

METHOD

We retrospectively reviewed the charts of consecutive 670 patients who received 4,072 pedicle screws between December 2010 and August 2015. Another case series study was conducted prospectively in three additional hospitals, and 88 consecutive patients with 413 pedicle screws were enrolled from February 2014 to July 2016. The fluoroscopy shot number and radiation dose were recorded. In the prospective study, 78 patients with 371 screws received computed tomography at 3 months postoperatively to evaluate the fusion condition and screw positions.

RESULTS

In the retrospective series, the placement of a percutaneous screw required 5.1 shots (2-14, standard deviation [SD]=2.366) of AP fluoroscopy. One screw was revised because of a medialwall breach of the pedicle. In the prospective series, 5.8 shots (2-16, SD=2.669) were required forone percutaneous pedicle screw placement. There were two screws with a Grade 1 breach (8.6%), both at the lateral wall of the pedicle, out of 23 screws placed at the thoracic spine at T9-T12. Forthe lumbar and sacral areas, there were 15 Grade 1 breaches (4.3%), 1 Grade 2 breach (0.3%), and 1 Grade 3 breach (0.3%). No revision surgery was necessary.

CONCLUSION

This method avoids lateral shots of fluoroscopy during screw placement and thus decreases the operation time and exposes surgeons to less radiation. At the same time, compared with the computer-navigated procedure, it is less facility-demanding, and provides satisfactory reliability and accuracy.

Three dimensional printing technology and materials for treatment of elbow fractures

PURPOSE

3D printing is a rapid prototyping technology that uses a 3D digital model to physically build an object. The aim of this study was to evaluate the peri-operative effect of 3D printing in treating complex elbow fractures and its role in physician-patient communication and determine which material is best for surgical model printing.

METHOD

Forty patients with elbow fractures were randomly divided into a 3D printing-assisted surgery group (n = 20) and a conventional surgery group (n = 20). Surgery duration, intra-operative blood loss, anatomic reduction rate, incidence of complications and elbow function score were compared between the two groups. The printing parameters, the advantages and the disadvantages of PLA and ABS were also compared. The independent-samples t-test was used to compare the data between groups. A questionnaire was designed for orthopaedic surgeons to evaluate the verisimilitude, the appearance of being true or real, and effectiveness of the 3D printing fracture model. Another questionnaire was designed to evaluate physician-patient communication effectiveness.

RESULTS

The 3D group showed shorter surgical duration, lower blood loss and higher elbow function score, compared with the conventional group. PLA is an environmentally friendly material, whereas ABS produce an odour in the printing process. Curling edges occurred easily in the printing process with ABS and were observed in four of ten ABS models but in only one PLA model. The overall scores given by the surgeons about the verisimilitude and effectiveness of the 3D model were relatively high. Patient satisfaction scores for the 3D model were higher than those for the 2D imaging data during physician-patient discussions.

CONCLUSION

3D-printed models can accurately depict the anatomic characteristics of fracture sites, help surgeons determine a surgical plan and represent an effective tool for physician-patient communication. PLA is more suitable for desktop fused deposition printing in surgical modeling applications.

Tranexamic Acid and Computer-Assisted Surgery in Cemented and Cementless Total Knee Arthroplasty: Are the Effects Additive for Blood Conservation?

INTRODUCTION

Efforts continue to minimize blood loss associated with total knee arthroplasty (TKA). The primary objective of this study was to determine whether computer-assisted surgery (CAS) and tranexamic acid (TXA) were additive in minimizing blood loss in cemented TKA. The secondary objective was to assess the combined effectiveness of CAS and TXA in cementless TKA.

MATERIALS AND METHODS

A retrospective study of 393 consecutive primary TKAs with cemented and cementless fixation was performed. Cemented and cementless fixation TKA cohorts were divided into three subgroups: (1) neither CAS nor TXA was used, (2) CAS alone was used, or (3) CAS plus TXA was used. Three blood loss metrics were calculated: (1) postoperative change in hemoglobin, (2) total drain output, and (3) calculated total blood loss.

RESULTS

After exclusions, 267 cemented TKAs and 35 cementless or hybrid TKAs were available for analysis. In cemented TKAs, the mean postoperative hemoglobin decrease was 2.9 g/dL in patients without CAS or TXA, 2.5 g/dL in the CAS only group, and 2.1 g/dL in the CAS and TXA group (p = 0.001). Median total drain output was lower in the CAS plus TXA group (230 ml) compared to the CAS alone (442.5 ml), and the neither CAS nor TXA group (620 ml) (p = 0.001). Mean calculated total blood loss was 1258.7 ml in the group with neither CAS nor TXA, 1023.8 ml in CAS alone, and 869.1 ml for both the CAS and TXA group (p = 0.001). In cementless TKA, the postoperative hemoglobin drop decreased from 3.3 g/dL in the neither CAS nor TXA group to 2.5 g/dL with CAS alone and 1.9 g/dL in the CAS plus TXA (p = 0.024). Mean total drain output progressively declined with CAS alone and for those with CAS plus TXA compared to those without CAS or TXA (p = 0.004).

CONCLUSIONS

An encouraging additive decrease in blood loss after TKA can occur with utilization of both CAS and TXA. The additive effect of both modalities appears to exist in cemented and cementless fixation techniques. Whether this blood conservation will result in improved patient outcomes remains unknown and should be the topic of further study.

Facial nerve sparing surgery for large vestibular schwannomas

BACKGROUND

Nowadays, there is a general trend in vestibular schwannoma (VS) surgery favoring near-total or subtotal tumor resection (NTR/STR) with facial nerve (FN) function preservation rather than gross total resection (GTR) with high risk of FN damage.

METHODS

The surgical technique of FN sparing in large VS includes patient-tailored image-guided craniotomy, continuous intraoperative neurophysiological monitoring (INM), intracapsular wide tumor debulking, and only final extracapsular dissection with FN course identification and brainstem decompression. A small amount of residual tumor along the FN is accepted in order to not damage the nerve. Postoperative radiosurgery workup is then recommended.

CONCLUSIONS

NTR/STR resection with FN function sparing is a valid option for large VS.

Spinal intraoperative three-dimensional navigation: correlation between clinical and absolute engineering accuracy

BACKGROUND CONTEXT

Spinal intraoperative computer-assisted navigation (CAN) may guide pedicle screw placement. Computer-assisted navigation techniques have been reported to reduce pedicle screw breach rates across all spinal levels. However, definitions of screw breach vary widely across studies, if reported at all. The absolute quantitative error of spinal navigation systems is theoretically a more precise and generalizable metric of navigation accuracy. It has also been computed variably and reported in less than a quarter of clinical studies of CAN-guided pedicle screw accuracy.

PURPOSE

This study aimed to characterize the correlation between clinical pedicle screw accuracy, based on postoperative imaging, and absolute quantitative navigation accuracy.

DESIGN/SETTING

This is a retrospective review of a prospectively collected cohort.

PATIENT SAMPLE

We recruited 30 patients undergoing first-time posterior cervical-thoracic-lumbar-sacral instrumented fusion±decompression, guided by intraoperative three-dimensional CAN.

OUTCOME MEASURES

Clinical or radiographic screw accuracy (Heary and 2 mm classifications) and absolute quantitative navigation accuracy (translational and angular error in axial and sagittal planes).

METHODS

We reviewed a prospectively collected series of 209 pedicle screws placed with CAN guidance. Each screw was graded clinically by multiple independent raters using the Heary and 2 mm classifications. Clinical grades were dichotomized per convention. The absolute accuracy of each screw was quantified by the translational and angular error in each of the axial and sagittal planes.

RESULTS

Acceptable screw accuracy was achieved for significantly fewer screws based on 2 mm grade versus Heary grade (92.6% vs. 95.1%, p=.036), particularly in the lumbar spine. Inter-rater agreement was good for the Heary classification and moderate for the 2 mm grade, significantly greater among radiologists than surgeon raters. Mean absolute translational-angular accuracies were 1.75 mm-3.13° and 1.20 mm-3.64° in the axial and sagittal planes, respectively. There was no correlation between clinical and absolute navigation accuracy.

CONCLUSIONS

Radiographic classifications of pedicle screw accuracy vary in sensitivity across spinal levels, as well as in inter-rater reliability. Correlation between clinical screw grade and absolute navigation accuracy is poor, as surgeons appear to compensate for navigation registration error. Future studies of navigation accuracy should report absolute translational and angular errors. Clinical screw grades based on postoperative imaging may be more reliable if performed in multiple by radiologist raters.

Persistent fibrosis, hypertrophy and sarcomere disorganisation after endoscopy-guided heart resection in adult Xenopus

Models of cardiac repair are needed to understand mechanisms underlying failure to regenerate in human cardiac tissue. Such studies are currently dominated by the use of zebrafish and mice. Remarkably, it is between these two evolutionary separated species that the adult cardiac regenerative capacity is thought to be lost, but causes of this difference remain largely unknown. Amphibians, evolutionary positioned between these two models, are of particular interest to help fill this lack of knowledge. We thus developed an endoscopy-based resection method to explore the consequences of cardiac injury in adult Xenopus laevis. This method allowed in situ live heart observation, standardised tissue amputation size and reproducibility. During the first week following amputation, gene expression of cell proliferation markers remained unchanged, whereas those relating to sarcomere organisation decreased and markers of inflammation, fibrosis and hypertrophy increased. One-month post-amputation, fibrosis and hypertrophy were evident at the injury site, persisting through 11 months. Moreover, cardiomyocyte sarcomere organisation deteriorated early following amputation, and was not completely recovered as far as 11 months later. We conclude that the adult Xenopus heart is unable to regenerate, displaying cellular and molecular marks of scarring. Our work suggests that, contrary to urodeles and teleosts, with the exception of medaka, adult anurans share a cardiac injury outcome similar to adult mammals. This observation is at odds with current hypotheses that link loss of cardiac regenerative capacity with acquisition of homeothermy.

Automatic Estimation of Optimal Deployment of Transcatheter Aortic Valve Implantation Using Computed Tomography

BACKGROUND

A comparison was made between the accuracy of and time saved by using novel automated software for pre-procedural computed tomography (CT) planning before transcatheter aortic valve implantation (TAVI) and manual methods. Preprocedural CT to assess aortic annulus dimensions and predict the optimal C-arm implant angle before TAVI can reduce complications related to incorrect prosthesis sizing and positioning.

METHODS

A total of 61 consecutive patients underwent TAVI using either the SAPIEN XT or CoreValve prosthesis. Pre-procedural CT scans were analysed using three methods: automatic; semi-automatic; and manual. For each method, annular dimensions were measured and the optimal implantation angle was predicted. After TAVI the actual post-deployment angle orthogonal to the prosthesis was determined using aortic fluoroscopy. The difference between the predicted angle by CT and the measured post-deployment angle was calculated for each method.

RESULTS

For all methods the mean angular difference with the actual post-deployment angle was similar at ~9 ± 7°. There was a significant difference between the SAPIEN XT (6.6 ± 5.8°) and CoreValve (11.5 ± 6.9°, p <0.001) prostheses due to a consistently greater left anterior oblique and caudal angulation for the CoreValve. Although the annular area correlated well among all methods, 'automatic' results were consistently larger than 'manual' results. Interobserver variability was low for all measures. The fully automatic method saved 98 s, and the semiautomatic method 40 s per case.

CONCLUSIONS

The use of automatic software enabled a rapid and accurate prediction of implantation angles, though results differed for specific manufacturers. Annular areas were overestimated by the automatic method, and thus required manual adjustments.

[Combined approach for parotid lithiases: A 9 cases retrospective study]

INTRODUCTION

Minimally invasive techniques (MIT), including sialendoscopy, extracorporeal lithotripsy and intraoral approach, have to be preferred in parotid stones removal. In case of MIT failure, a combined intra- and extra-oral approach can be achieved. The aim of our study was to evaluate the efficacy and the complications of these combined approaches.

MATERIALS AND METHODS

A retrospective study has been conducted on patients treated between 2006 and 2015. All adult patients presenting with one or more parotid stones and in whom TMI failed have been included. Age and sex of the patients, number, size and location of the stones, result of the procedure, occurrence of pain, swelling, or infection have been recorded.

RESULTS

Nine patients were included (mean age: 56). Mean follow-up was 48 months. Eighty-eight percent of patients had an unique stone. Nine stones were extracted by combined approach. Mean diameter of the stones was 8.5mm and 33% of them were located at the junction between middle and posterior third of parotid duct. All the patients suffered preoperatively from daily retention symptoms, such as pain (55%) and swelling (100%). Two patients had an infectious complication (duct and/or gland infection). Seventy-five percent (9/12) of stones were removed. Complications consisted of 1 fistula, 1 facial paresis, 3 recurrences. Seven of 9 patients (77%) had a total relieve after surgery.

DISCUSSION

Surgical combined approaches for parotid stones removals are indicated after failure of MIT when symptoms affect quality of life.

Laser neurosurgery: A systematic analysis of magnetic resonance-guided laser interstitial thermal therapies

Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) is a novel minimally invasive modality that uses heat from laser probes to destroy tissue. Advances in probe design, cooling mechanisms, and real-time MR thermography have increased laser utilization in neurosurgery. The authors perform a systematic analysis of two commercially available MRgLITT systems used in neurosurgery: the Visualase® thermal therapy and NeuroBlate® Systems. Data extraction was performed in a blinded fashion. Twenty-two articles were included in the quantitative synthesis. A total of 223 patients were identified with the majority having undergone treatment with Visualase (n=154, 69%). Epilepsy was the most common indication for Visualase therapy (n=8 studies, 47%). Brain mass was the most common indication for NeuroBlate therapy (n=3 studies, 60%). There were no significant differences, except in age, wherein the NeuroBlate group was nearly twice as old as the Visualase group (p<0.001). Frame, total complications, and length-of-stay (LOS) were non-significant when adjusted for age and number of patients. Laser neurosurgery has evolved over recent decades. Clinical indications are currently being defined and will continue to emerge as laser technologies become more sophisticated. Head-to-head comparison of these systems was difficult given the variance in indications (and therefore patient population) and disparate literature.

The evolving utility of diffusion tensor tractography in the surgical management of temporal lobe epilepsy: a review

BACKGROUND

Diffusion tensor imaging (DTI) is a relatively new imaging modality that has found many peri-operative applications in neurosurgery.

METHODS

A comprehensive survey of the applications of diffusion tensor imaging (DTI) in planning for temporal lobe epilepsy surgery was conducted. The presentation of this literature is supplemented by a case illustration.

RESULTS

The authors have found that DTI is well utilized in epilepsy surgery, primarily in the tractography of Meyer's loop. DTI has also been used to demonstrate extratemporal connections that may be responsible for surgical failure as well as perioperative planning. The tractographic anatomy of the temporal lobe is discussed and presented with original DTI pictures.

CONCLUSIONS

The uses of DTI in epilepsy surgery are varied and rapidly evolving. A discussion of the technology, its limitations, and its applications is well warranted and presented in this article.

Navigated vs Conventional Total Knee Arthroplasty: Is There a Difference in the Rate of Respiratory Complications and Transfusions?

BACKGROUND

Proponents of navigation in total knee arthroplasty (TKA) report lower rates of systemic embolization and perioperative bleeding compared to conventional TKA given that breeching the intramedullary canal is not required.

METHODS

We queried the National Surgical Quality Improvement Program to compare perioperative respiratory complications and transfusions between navigated and conventional TKA. We identified 2008 patients who underwent navigated TKA. These patients were matched 4:1 to a control group of 8026 patients.

RESULTS

Conventional TKA resulted in similar odds of having a respiratory complication compared to navigated TKA (odds ratio = 1.35, P = .44). However, conventional TKA was found to be an independent predictor for requiring a transfusion perioperatively (odds ratio = 1.90, P < .001).

CONCLUSION

Use of navigation in TKA results in less perioperative transfusions but has no influence on the rate of respiratory complications.

No Benefit After THA Performed With Computer-assisted Cup Placement: 10-year Results of a Randomized Controlled Study

BACKGROUND

Computer-assisted surgery (CAS) for cup placement has been developed to improve the functional results and to reduce the dislocation rate and wear after total hip arthroplasty (THA). Previously published studies demonstrated radiographic benefits of CAS in terms of implant position, but whether these improvements result in clinically important differences that patients might perceive remains largely unknown.

QUESTIONS/PURPOSES

We hypothesized that THA performed with CAS would improve 10-year patient-reported outcomes measured by validated scoring tools, reduce acetabular polyethylene wear as measured using a validated radiological method, and increase survivorship.

METHODS

Sixty patients operated on for a THA between April 2004 and April 2005 were randomized into two groups using either the CAS technique or a conventional technique for cup placement. All patient candidates for a THA with the diagnosis of primary arthritis or avascular necrosis were eligible for the CAS procedure and randomly assigned to the CAS group by the Hospital Informatics Department with use of a systematic sampling method. The patients assigned to the freehand cup placement group were matched for sex, age within 5 years, pathological condition, operatively treated side, and body mass index within 3 points. All patients were operated on through an anterolateral approach (patient in the supine position) using cementless implants. In the CAS group, a specific surgical procedure using an imageless cup positioning computer-based navigation system was performed. There were 16 men and 14 women in each group; mean age was 62 years (range, 24-80 years), and mean body mass index was 25 ± 3 kg/m(2). No patient was lost to followup at 10 years, but five patients have died (two in the CAS group and three in the control group). At the 10-year followup, an independent observer blinded to the type of technique performed patients' evaluation. Cup positioning was evaluated postoperatively using a CT scan in the two groups with results previously published. At 10 years, we assessed subjective functional outcome and quality of life using validated questionnaires (SF-12, Harris hip score [HHS], Hip injury and Osteoarthritis Outcome Score). Wear rate was then evaluated on standardized radiographs using a previously validated semiautomated computer analogic measurement method (dual circle method). Complications and survivorship were compared between groups. With our available sample size, this study had 80% power to detect a difference of 4 points out of 100 on the HHS at the p < 0.05 level.

RESULTS

With the numbers available, we found we found no differences between groups regarding HSS at last followup 95.3 ± 5.9 points (CAS group) versus 96.2 ± 4.5 points, a mean difference of 0.9 points (95% confidence interval [CI], -4.3 to 4.6; p = 0.6). There was no difference between the groups in terms of the mean (± SD) acetabular linear wear at 10 years. The mean wear was 0.71 ± 0.6 mm in the CAS group versus 0.77 ± 0.52 mm in the control group, a mean difference of 0.06 mm (95% CI, -0.1 to 0.2; p = 0.54). With the numbers available, there was no difference between the CAS group and the conventional THA groups in terms of survivorship free from aseptic loosening (100%; 95% CI, 100%-95%, versus 100%; 95% CI, 100%-94%; p = 0.3).

CONCLUSIONS

Our observations suggest that CAS used for cup placement does not confer any substantial advantage in function, wear rate, or survivorship at 10 years after THA. Because CAS is associated with added costs and surgical time, future studies need to identify what clinically relevant advantages it offers, if any, to justify its continued use in THA.

LEVEL OF EVIDENCE

Level II, therapeutic study.

Zero x-ray cardiac resynchronization therapy device implantation guided by a nonfluoroscopic mapping system: A pilot study

BACKGROUND

Fluoroscopic guidance is the standard tool used in device implantation. This means that both the patient and the operator are exposed to radiation, which may sometimes be high. The possibility of single-lead permanent pacemaker implantation without fluoroscopy has already been demonstrated.

OBJECTIVE

The aim of our study was to investigate the feasibility and reliability of biventricular device implantation guided only by an electroanatomic navigation system.

METHODS

Sixty-one patients with heart failure underwent implantation of a cardiac resynchronization therapy (CRT) device with or without defibrillator (CRT-D; CRT-P). The procedure was performed with or without fluoroscopy guidance (Rx+; Rx0). In the latter case, the EnSite Velocity system was used; this system is able to reconstruct the anatomy and activation of the cardiac chambers by simultaneously collecting a "cloud" of anatomical points from multiple electrodes.

RESULTS

Lead positioning was achieved in 24 of 26 patients undergoing CRT implantation without fluoroscopy (92% success). No complications were observed during the procedure and no catheter dislodgment occurred the day after the implantation or during 1-month follow-up. Procedure time progressively decreased from 136 minutes in the first case to 59 minutes in the last one, suggesting that operators gradually gained confidence while using the new technique.

CONCLUSION

Our study demonstrates the feasibility, efficacy, and safety of lead positioning guided only by the nonfluoroscopic EnSite Velocity mapping system without the use of fluoroscopy in CRT-P or CRT-D implantation. The benefits in terms of significantly reduced fluoroscopy exposure are associated with technical and clinical advantages.

Ultrasound-guided open nephron sparing surgery without renal artery occlusion for central renal tumors

From January 2008 to January 2013, 11 patients with central renal tumors underwent ultrasound-guided open nephron sparing surgery (ONSS) without renal artery occlusion. We removed the lesions, and the cut edges of the tumors were negative. Thus, we deduced that ultrasound-guided ONSS is suitable for the cases with obscure tumor boundary or multiple lesions. It could achieve the purpose of thoroughly removing lesions, as well as to expand the application range of nephron sparing surgery.

Economic evaluation comparing intraoperative cone beam CT-based navigation and conventional fluoroscopy for the placement of spinal pedicle screws: a patient-level data cost-effectiveness analysis

BACKGROUND CONTEXT

Pedicle screws are routinely used in contemporary spinal surgery. Screw misplacement may be asymptomatic but is also correlated with potential adverse events. Computer-assisted surgery (CAS) has been associated with improved screw placement accuracy rates. However, this technology has substantial acquisition and maintenance costs. Despite its increasing usage, no rigorous full economic evaluation comparing this technology to current standard of care has been reported.

PURPOSE

Medical costs are exploding in an unsustainable way. Health economic theory requires that medical equipment costs be compared with expected benefits. To answer this question for computer-assisted spinal surgery, we present an economic evaluation looking specifically at symptomatic misplaced screws leading to reoperation secondary to neurologic deficits or biomechanical concerns.

STUDY DESIGN/SETTING

The study design was an observational case-control study from prospectively collected data of consecutive patients treated with the aid of CAS (treatment group) compared with a matched historical cohort of patients treated with conventional fluoroscopy (control group).

PATIENT SAMPLE

The patient sample consisted of consecutive patients treated surgically at a quaternary academic center.

OUTCOME MEASURES

The primary effectiveness measure studied was the number of reoperations for misplaced screws within 1 year of the index surgery. Secondary outcome measures included were total adverse event rate and postoperative computed tomography usage for pedicle screw examination.

METHODS

A patient-level data cost-effectiveness analysis from the hospital perspective was conducted to determine the value of a navigation system coupled with intraoperative 3-D imaging (O-arm Imaging and the StealthStation S7 Navigation Systems, Medtronic, Louisville, CO, USA) in adult spinal surgery. The capital costs for both alternatives were reported as equivalent annual costs based on the annuitization of capital expenditures method using a 3% discount rate and a 7-year amortization period. Annual maintenance costs were also added. Finally, reoperation costs using a micro-costing approach were calculated for both groups. An incremental cost-effectiveness ratio was calculated and reported as cost per reoperation avoided. Based on reoperation costs in Canada and in the United States, a minimal caseload was calculated for the more expensive alternative to be cost saving. Sensitivity analyses were also conducted.

RESULTS

A total of 5,132 pedicle screws were inserted in 502 patients during the study period: 2,682 screws in 253 patients in the treatment group and 2,450 screws in 249 patients in the control group. Overall accuracy rates were 95.2% for the treatment group and 86.9% for the control group. Within 1 year post treatment, two patients (0.8%) required a revision surgery in the treatment group compared with 15 patients (6%) in the control group. An incremental cost-effectiveness ratio of $15,961 per reoperation avoided was calculated for the CAS group. Based on a reoperation cost of $12,618, this new technology becomes cost saving for centers performing more than 254 instrumented spinal procedures per year.

CONCLUSIONS

Computer-assisted spinal surgery has the potential to reduce reoperation rates and thus to have serious cost-effectiveness and policy implications. High acquisition and maintenance costs of this technology can be offset by equally high reoperation costs. Our cost-effectiveness analysis showed that for high-volume centers with a similar case complexity to the studied population, this technology is economically justified.

Feasibility, Safety, and Efficacy of Accurate Uterine Fibroid Ablation Using Magnetic Resonance Imaging-Guided High-Intensity Focused Ultrasound With Shot Sonication

The aim of this study was to investigate the feasibility, safety, and efficacy of uterine fibroid treatment using magnetic resonance imaging (MRI)-guided high-intensity focused ultrasound (US) with shot sonication for accurate ablation. Forty-three patients with 51 symptomatic uterine fibroids were treated with MRI-guided high-intensity focused US with shot sonication, which was a small acoustic focus of higher intensity with a shorter time (2 seconds) of US exposure and a shorter cooling time (2-3 seconds). The treatment efficacy and adverse events were analyzed, and the changes in the severity of symptoms and the reduction in fibroid volume were assessed 3 and 6 months after the procedure. All patients were successfully treated in a single session, without major complications, and the mean nonperfused volume ratio ± SD was 84.3% ± 15.7% (range, 33.8%-100%).Complete ablation was achieved in 13 T2-hypointense fibroids from 10 patients, and partial ablation was achieved in 38 fibroids from 33 patients. The overall mean treatment time was 135.0 ± 50.9 minutes (2.2 ± 0.8 hours). The transformed symptom severity scores and mean fibroid volumes decreased significantly after treatment (P < .05). In conclusion, MRI-guided high-intensity focused US with shot sonication is a feasible, safe, and effective technique for ablation of uterine fibroids and complete ablation of T2-hypointense fibroids.