Pedicle Screw Placement Research Articles

Comparison Between Resident and Attending Surgeons as Assistants on Adolescent Idiopathic Scoliosis Surgery: No Differences in Outcomes, Complications Rate, or Pedicle Screw Placement Accuracy.

Retrospective cohort study. The aim of the present study was to determine if the level of training of the first assistant (resident or attending surgeon) has an influence on the radiographic outcome of AIS surgery and on the accuracy rate of the pedicle screws placement. Adolescent idiopathic scoliosis (AIS) surgery is a challenging procedure that requires a dedicated team of skilled professionals. Therefore, understanding the learning curve is of outstanding importance to guarantee the best outcomes and the highest safety to the patients. A retrospective analysis of patients who underwent surgery for AIS with a minimum follow-up of 2 years was conducted. All patients were operated by an experienced spine surgeon, assisted by and attending surgeon (group A) or a senior resident (group B). Radiographic outcomes were assessed. Through postoperative CT scan, accuracy of pedicle screw placement was measured (using Gertzbein-Robbins classification). Groups were then statistically compared. A total of 120 patients were included (mean age 15.3±3.39y, major curve Cobb 60.7±11.9 degrees). No difference was found between groups in terms of preoperative characteristics and postoperative radiographic (correction rate, thoracic kyphosis, screw density) outcomes or complications. Operative time and estimated blood loss were significantly higher in Group B (P=0.045 and P=0.024, respectively). Of the 2746 pedicle screws inserted (1319 group A and 1427 group B), 2452 had a perfect intrapedicular trajectory (absolute accuracy of 89.29%) and 2697 had a breach <2mm (relative accuracy of 97.56%). No difference was found among groups in terms of absolute or relative accuracy (P=0.06 and P=0.23, respectively). AIS cases assisted by senior residents have longer operative time and higher blood loss, but this does not negatively affect the overall radiographic outcome and does not place the patient at increased risk of complications. III.

Comparison of rostral facet joint violations in robotic- and navigation-assisted pedicle screw placement for adult lumbar spine instrumentation

BACKGROUND CONTEXTFacet joint violation by pedicle screws may lead to adjacent-segment disease and postoperative pain. Previous studies have reported the incidence of rostral facet joint violation using various pedicle screw insertion techniques. However, the incidence of facet joint violations with robotic guidance has not been determined. PURPOSETo investigate and compare the incidence of rostral facet joint violation by pedicle screws under robotic guidance and computerized tomography (CT) navigation guidance. STUDY DESIGN/SETTINGRetrospective matched cohort. PATIENT SAMPLEAll patients who underwent robotic-assisted lumbar fusion at a major spine center up until 2023 were retrospectively identified and matched 1:3 to patients undergoing CT navigation guidance based by on age, sex, rostral vertebral level, and length of construct. Inclusion criteria consisted of age greater than 18 years, bilateral pedicle screw fixation, and presence of a postoperative CT scan of the lumbar spine or abdomen/pelvis at any point in the post-operative period. OUTCOME MEASURESRostral facet joint violations. METHODSDescriptive statistics were used to compare cohorts: frequencies, chi-squared analysis for categorical variables, and t-test for continuous variables. RESULTSA total of 408 rostral pedicle screws were implanted in 204 patients (Robot: 102; Navigation: 306). Overall, 13 (12.3%) rostral facet joint violations were observed in the robot cohort and 75 (24.5%) in the navigation cohort (p=.01). Specifically, fewer robotic violations were observed at the L2 (3.5% vs. 32.1%, p=.003) and L3 levels (3.9% vs. 18.1%, p=.08) compared to navigation. No difference was observed at L4 and L5. Bilateral violations are significantly reduced with robotic approaches (5.3% vs. 14.4%, p=.03). Lastly, more facet joint violations were observed during open approaches (robot: 18.8%, navigation: 27.3%) than percutaneous approaches (robot: 11.6%, navigation: 7.1%) in both groups (p<.001). The rate of L4 facet violations was 18.8% in the robotic cohort and 27.3% in the navigation cohort. The rate of L5 facet violations was 31.3% in the robotic cohort and 29.2% in the navigation cohort. CONCLUSIONSUse of robotic assistance in lumbar pedicle screws significantly reduced the rate of rostral facet joint violations compared to navigation guidance at L2 and L3 levels, but not at L4 and L5, with facet violations approaching nearly one-third of the patients at L5 screws. Rostral facet violations can play a significant role in adjacent segment degeneration and disease. Technical factors and trajectory issues likely play a role and addressing these components should minimize unintended facet violation and proximal adding on.

A Network Meta-Analysis Comparing the Efficacy and Safety of Pedicle Screw Placement Techniques Using Intraoperative Conventional, Navigation, Robot-Assisted, and Augmented Reality Guiding Systems.

Studies were reviewed and collected to compare different image guidance systems for pedicle screw placement (PSP) regarding accuracy and safety outcomes. Included were conventional, navigation, robot-assisted, and recent technology such as augmented reality (AR) guiding systems. This network meta-analysis obtained human comparative studies and randomized controlled trials (RCTs) regarding PSP found in 3 databases (Cochrane, PubMed, and Scopus). Data extraction for accuracy, safety, and clinical outcomes were collected. The network meta-analysis was analyzed, and a surface under the cumulative ranking curve (SUCRA) was used to rank the treatment for all outcomes. The final 61 studies, including 13 RCTs and 48 non-RCTs, were included in the meta-analysis. These studies included a total of 17,023 patients and 35,451 pedicle screws. The surface under the cumulative ranking curve ranking demonstrated the supremacy of robotics in almost all accuracy outcomes except for the facet joint violation. Regarding perfect placement, the risk difference for AR was 19.1 (95% CI: 8.1-30.1), which was significantly higher than the conventional method. The robot-assisted and navigation systems had improved outcomes but were not significantly different in accuracy vs the conventional technique. There was no statistically significant difference concerning safety or clinical outcomes. The accuracy of PSP achieved by robot-assisted technology was the highest, whereas the safety and clinical outcomes of the different methods were comparable. The recent AR technique provided better accuracy compared with navigation and conventional methods.

C2 pedicle screw insertion assisted by mobilization of the vertebral artery in cases with high-riding vertebral artery

ObjectiveTo describe the feasibility, safety and efficacy of mobilization of the vertebral artery for C2 pedicle screws in cases with the high-riding vertebral artery (HRVA). MethodsDuring the period January 2020 to September 2022, fifteen patients underwent posterior occipitocervical fixation in our department. All patients had unilateral HRVA on at least one side that prohibited the insertion of C2 pedicle screws. There were 2 males and 13 females aged 47 ± 11.9 years (range: 17–64 years). After the correction of the vertical dislocation during the operation, the C2 pedicle screw insertion and occipitocervical fixation and fusion were performed using the vertebral artery mobilization technique. A routine three-dimensional reconstructed CT examination was executed to confirm the trajectory of C2 pedicle screws post-operation, and a CT angiography examination was performed when necessary. Neurological function was assessed using the Japanese Orthopedic Association (JOA) scale. The preoperative and postoperative JOA score and the main radiological measurements, including anterior atlantodental interval (ADI), the distance of odontoid tip above Chamberlain line, and clivus-canal angle (CCA), were collected and compared by paired t-test. ResultsAll 15 patients had atlas assimilation, among which 12 patients had C2–C3 fusion (Klippel-Feil syndrome). Mobilization of the HRVA was successfully completed, and C2 pedicle screws were then fulfilled after the vertebral artery was protected. There was no injury to the vertebral artery during the operation. Meanwhile, no severe surgical complications such as cerebral infarction or aggravated neurological dysfunction occurred during the perioperative period. Satisfactory C2 pedicle screw placement and reduction were reached in all 15 patients. All the patients achieved bone fusion 6 months after surgery. No looseness and shift of internal fixation or reduction loss was observed during the follow-up period. Compared to the preoperative, the postoperative JOA score and the main radiological measurements were remarkably improved and statistically significant. ConclusionsC2 pedicle screw insertion assisted by mobilization of the vertebral artery is safe and considerably effective, providing a choice for internal fixation in cases with high-riding vertebral arteries.

Single-position oblique lumbar interbody fusion with navigation: improved efficiency and screw accuracy compared to dual-position with fluoroscopy

Dual-position oblique lumbar interbody fusion with fluoroscopy (D-OLIF) requires repositioning the patient to a prone position for pedicle screw insertion. Recently, single-position surgery with navigation has been introduced. However, there are concerns regarding pedicle screw accuracy and achieving appropriate sagittal balance in single-position OLIF with navigation (S-OLIF). The purpose of this study is to evaluate the clinical and radiological outcomes of S-OLIF compared to D-OLIF. A retrospective analysis was conducted on 102 patients who underwent single-level OLIF at a single institution. The patients were divided into two groups: 55 in the S-OLIF group and 47 in the D-OLIF group. The numeric rating scale for back and leg, Oswestry disability index, and walking distance improvements showed no significant difference. However, the EuroQol 5-dimension 5-level index showed higher improvement in the S-OLIF (P = 0.029). The segmental lordosis, lumbar lordosis, and C7 sagittal vertical axis showed no significant difference. S-OLIF had significantly fewer cases of pedicle screw malposition (P = 0.045). Additionally, the surgery time was shorter in the S-OLIF (P = 0.002). In conclusion, S-OLIF exhibited clinical and radiological outcomes comparable to D-OLIF, with the added advantages of reduced surgery time and enhanced accuracy in pedicle screw placement.

Robotic Spine Surgery: Systematic Review of Common Error Types and Best Practices.

Robotic systems have emerged as a significant advancement in the field of spine surgery. They offer improved accuracy in pedicle screw placement and reduce intraoperative complications, hospital length of stay, blood loss, and radiation exposure. As the use of robotics in spine surgery continues to grow, it becomes imperative to understand common errors and challenges associated with this new and promising technology. Although the reported accuracy of robot-assisted pedicle screw placement is very high, the current literature does not capture near misses or incidental procedural errors that might have been managed during surgery or did not alter treatment of patients. We evaluated errors that occur during robot-assisted pedicle screw insertion and identify best practices to minimize their occurrence. In this systematic review, we characterized 3 types of errors encountered during robot-assisted pedicle screw insertion-registration errors, skiving, and interference errors-that have been reported in the literature. Our search yielded 13 relevant studies reporting robot-assisted screw errors. Nine studies reported registration errors, with 60% of failed screws in those studies caused by registration issues. Seven studies highlighted skiving errors; 26.8% of the failed screws in those studies were caused by skiving. Finally, interference errors were reported in 4 studies, making up 19.5% of failed screws. On the basis of these findings, we suggest best practices-including close attention to preoperative planning, patient positioning, image registration, and equipment selection-to minimize the occurrence of these errors. Awareness of how errors occur may increase the safety of this technology.

The accuracy of intraoperative O-arm imaging in assessing thoracolumbar pedicle screws placement

The accuracy of intraoperative O-arm imaging in assessing thoracolumbar pedicle screws placement

Biomechanical effects of posterior lumbar interbody fusion with vertical placement of pedicle screws compared to traditional placement.

The pedicle screw technique is widely employed for vertebral body fixation in the treatment of spinal disorders. However, traditional screw placement methods require the dissection of paraspinal muscles and the insertion of pedicle screws at specific transverse section angles (TSA). Larger TSA angles require more force to pull the muscle tissue, which can increase the risk of surgical trauma and ischemic injury to the lumbar muscles. To study the feasibility of zero-degree TSA vertical pedicle screw technique in the lumbosacral segment. Finite element models of vertebral bodies and pedicle screw-rod systems were established for the L4-S1 spinal segments. A standard axial load of 500 N and a rotational torque of 10 N/m were applied. Simulated screw pull-out experiment was conducted to observe pedicle screw resistance to pull-out, maximum stress, load-displacement ratio, maximum stress in vertebral bodies, load-displacement ratio in vertebral bodies, and the stress distribution in pedicle screws and vertebral bodies. Differences between the 0-degree and 17-degree TSA were compared. At 0-degree TSA, the screw pull-out force decreased by 11.35% compared to that at 17-degree TSA (P < 0.05). At 0-degree and 17-degree TSA, the stress range in the screw-rod system was 335.1-657.5 MPa and 242.8-648.5 MPa, separately, which were below the fracture threshold for the screw-rod system (924 MPa). At 0-degree and 17-degree TSA, the stress range in the vertebral bodies was 68.45-78.91 MPa and 39.08-72.73 MPa, separately, which were below the typical bone yield stress range for vertebral bodies (110-125 MPa). At 0-degree TSA, the load-displacement ratio for the vertebral bodies and pedicle screws was slightly lower compared to that at 17-degree TSA, indicating slightly lower stability (P < 0.05). The safety and stability of 0-degree TSA are slightly lower, but the risks of screw-rod system fracture, vertebral body fracture, and rupture are within acceptable limits.

Comparison of robot-assisted versus fluoroscopy-guided transforaminal lumbar interbody fusion (TLIF) for lumbar degenerative diseases: a systematic review and meta-analysis of randomized controlled trails and cohort studies

BackgroundAs an emerging technology in robot-assisted (RA) surgery, the potential benefits of its application in transforaminal lumbar interbody fusion (TLIF) lack substantial support from current evidence.ObjectiveWe aimed to investigate whether the RA TLIF is superior to FG TLIF in the treatment of lumbar degenerative disease.MethodsWe systematically reviewed studies comparing RA versus FG TLIF for lumbar degenerative diseases through July 2022 by searching PubMed, Embase, Web of Science, CINAHL (EBSCO), Chinese National Knowledge Infrastructure (CNKI), WanFang, VIP, and the Cochrane Library, as well as the references of published review articles. Both cohort studies (CSs) and randomized controlled trials (RCTs) were included. Evaluation criteria included the accuracy of percutaneous pedicle screw placement, proximal facet joint violation (FJV), radiation exposure, duration of surgery, estimated blood loss (EBL), and surgical revision. Methodological quality was assessed using the Cochrane risk of bias and ROBINS-I Tool. Random-effects models were used, and the standardized mean difference (SMD) was employed as the effect measure. We conducted subgroup analyses based on surgical type, the specific robot system used, and the study design. Two investigators independently screened abstracts and full-text articles, and the certainty of evidence was graded using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach.ResultsOur search identified 539 articles, of which 21 met the inclusion criteria for quantitative analysis. Meta-analysis revealed that RA had 1.03-folds higher “clinically acceptable” accuracy than FG (RR: 1.0382, 95% CI: 1.0273–1.0493). And RA had 1.12-folds higher “perfect” accuracy than FG group (RR: 1.1167, 95% CI: 1.0726–1.1626). In the case of proximal FJV, our results indicate a 74% reduction in occurrences for patients undergoing RA pedicle screw placement compared to those in the FG group (RR: 0.2606, 95%CI: 0.2063- 0.3293). Seventeen CSs and two RCTs reported the duration of time. The results of CSs suggest that there is no significant difference between RA and FG group (SMD: 0.1111, 95%CI: -0.391–0.6131), but the results of RCTs suggest that the patients who underwent RA-TLIF need more surgery time than FG (SMD: 3.7213, 95%CI: 3.0756–4.3669). Sixteen CSs and two RCTs reported the EBL. The results suggest that the patients who underwent RA pedicle screw placement had fewer EBL than FG group (CSs: SMD: -1.9151, 95%CI: -3.1265–0.7036, RCTs: SMD: -5.9010, 95%CI: -8.7238–3.0782). For radiation exposure, the results of CSs suggest that there is no significant difference in radiation time between RA and FG group (SMD: -0.5256, 95%CI: -1.4357–0.3845), but the patients who underwent RA pedicle screw placement had fewer radiation dose than FG group (SMD: -2.2682, 95%CI: -3.1953–1.3411). And four CSs and one RCT reported the number of revision case. The results of CSs suggest that there is no significant difference in the number of revision case between RA and FG group (RR: 0.4087,95% CI 0.1592–1.0495). Our findings are limited by the residual heterogeneity of the included studies, which may limit the interpretation of the results.ConclusionIn TLIF, RA technology exhibits enhanced precision in pedicle screw placement when compared to FG methods. This accuracy contributes to advantages such as the protection of adjacent facet joints and reductions in intraoperative radiation dosage and blood loss. However, the longer preoperative preparation time associated with RA procedures results in comparable surgical duration and radiation time to FG techniques. Presently, FG screw placement remains the predominant approach, with clinical surgeons possessing greater proficiency in its application. Consequently, the integration of RA into TLIF surgery may not be considered the optimal choice.Systematic review registrationPROSPERO CRD42023441600.

Fully automated determination of robotic pedicle screw accuracy and precision utilizing computer vision algorithms

Historically, pedicle screw accuracy measurements have relied on CT and expert visual assessment of the position of pedicle screws relative to preoperative plans. Proper pedicle screw placement is necessary to avoid complications, cost and morbidity of revision procedures. The aim of this study was to determine accuracy and precision of pedicle screw insertion via a novel computer vision algorithm using preoperative and postoperative computed tomography (CT) scans. Three cadaveric specimens were utilized. Screw placement planning on preoperative CT was performed according to standard clinical practice. Two experienced surgeons performed bilateral T2–L4 instrumentation using robotic-assisted navigation. Postoperative CT scans of the instrumented levels were obtained. Automated segmentation and computer vision techniques were employed to align each preoperative vertebra with its postoperative counterpart and then compare screw positions along all three axes. Registration accuracy was assessed by preoperatively embedding spherical markers (tantalum beads) to measure discrepancies in landmark alignment. Eighty-eight pedicle screws were placed in 3 cadavers’ spines. Automated registrations between pre- and postoperative CT achieved sub-voxel accuracy. For the screw tip and tail, the mean three-dimensional errors were 1.67 mm and 1.78 mm, respectively. Mean angular deviation of screw axes from plan was 1.58°. For screw mid-pedicular accuracy, mean absolute error in the medial–lateral and superior–inferior directions were 0.75 mm and 0.60 mm, respectively. This study introduces automated algorithms for determining accuracy and precision of planned pedicle screws. Our accuracy outcomes are comparable or superior to recent robotic-assisted in vivo and cadaver studies. This computerized workflow establishes a standardized protocol for assessing pedicle screw placement accuracy and precision and provides detailed 3D translational and angular accuracy and precision for baseline comparison.

Applications and accuracy of 3D-printed surgical guides in traumatology and orthopaedic surgery: A systematic review and meta-analysis.

Patient-Specific Surgical Guides (PSSGs) are advocated for reducing radiation exposure, operation timeand enhancing precision in surgery. However, existing accuracy assessments are limited to specific surgeries, leaving uncertainties about variations in accuracy across different anatomical sites, three-dimensional (3D) printing technologiesand manufacturers (traditional vs. printed at the point of care). This study aimed to evaluate PSSGs accuracy in traumatology and orthopaedic surgery, considering anatomical regions, printing methodsand manufacturers. A systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Studies were eligible if they (1) assessed the accuracy of PSSGs by comparing preoperative planning and postoperative results in at least two different planes (2) used either computer tomography or magnetic resonance imaging (3) covered the field of orthopaedic surgery or traumatologyand (4) were available in English or German language. The 'Quality Assessment Tool for Quantitative Studies' was used for methodological quality assessment. Descriptive statistics, including mean, standard deviation, and ranges, are presented. A random effectsmeta-analysis was performed to determine the pooled mean absolute deviation between preoperative plan and postoperative result for each anatomic region (shoulder, hip, spine, and knee). Of 4212 initially eligible studies, 33 were included in the final analysis (8 for shoulder, 5 for hip, 5 for spine, 14 for knee and 1 for trauma). Pooled mean deviation (95% confidence interval) for total knee arthroplasty (TKA), total shoulder arthroplasty (TSA), total hip arthroplasty (THA)and spine surgery (pedicle screw placement during spondylodesis) were 1.82° (1.48, 2.15), 2.52° (1.9, 3.13), 3.49° (3.04, 3.93)and 2.67° (1.64, 3.69), respectively. Accuracy varied between TKA and THA and between TKA and TSA. Accuracy of PSSGs depends on the type of surgery but averages around 2-3° deviation from the plan. The use of PSSGs might be considered for selected complex cases. Level 3 (meta-analysis including Level 3 studies).

Comparison of accuracy, revision, and perioperative outcomes in robot-assisted spine surgeries: systematic review and meta-analysis.

Pedicle screw placement guidance is critical in spinal fusions, and spinal surgery robots aim to improve accuracy and reduce complications. Current literature has yet to compare the relative merits of available robotic systems. In this review, the authors aimed to 1) assess the current state of spinal robotics literature; 2) conduct a meta-analysis of robotic performance based on accuracy, speed, and safety; and 3) offer recommendations for robotic system selection. Following PRISMA guidelines, the authors conducted a systematic literature review across PubMed, Embase, Cochrane Library, Web of Science, and Scopus as of April 28, 2022, for studies on approved robots for placing lumbar pedicle screws. Three reviewers screened and extracted data relating to the study characteristics, accuracy rate, intraoperative revisions, and reoperations. Secondary performance metrics included operative time, blood loss, and radiation exposure. The authors statistically compared the performance of the robots using a random-effects model to account for variation within and between the studies. Each robot was also compared with performance benchmarks of traditional techniques including freehand, fluoroscopic, and CT-navigated insertion. Finally, we performed a Duval and Tweedie trim-and-fill test to assess for the presence of publication bias. The authors identified 46 studies, describing 4670 patients and 25,054 screws, that evaluated 4 different robotic systems: Mazor X, ROSA, ExcelsiusGPS, and Cirq. The weighted accuracy rates of Gertzbein-Robbins classification grade A or B screws were as follows: ExcelsiusGPS, 98.0%; ROSA, 98.0%; Mazor, 98.2%; and Cirq, 94.2%. No robot was significantly more accurate than the others. However, the accuracy of the ExcelsiusGPS was significantly higher than that of traditional methods, and the accuracies of the Mazor and ROSA were significantly higher than that of fluoroscopy. The intraoperative revision rates were Cirq, 0.55%; ROSA, 0.91%; Mazor, 0.98%; and ExcelsiusGPS, 1.08%. The reoperation rates were Cirq, 0.28%; ExcelsiusGPS, 0.32%; and Mazor, 0.76% (no reoperations were reported for ROSA). Operative times were similar for all robots. Both the ExcelsiusGPS and Mazor were associated with significantly less blood loss than the ROSA. The Cirq had the lowest radiation exposure. Robots tended to be more accurate and generally their use was associated with fewer reoperations and less blood loss than freehand, fluoroscopic, or CT-navigated techniques. Robotic platforms perform comparably based on key metrics, with high accuracy rates and low intraoperative revision and reoperation rates. The spinal robotics publication rate will continue to accelerate, and choosing a robot will depend on the context of the practice.

Ultrasound propagation characteristics within the bone tissue of miniature ultrasound probes: implications for the spinal navigation of pedicle screw placement.

The accuracy of pedicle screw fixation is crucial for patient safety. Traditional navigation methods based on computed tomography (CT) imaging have several limitations. Therefore, this study aimed to investigate the ultrasonic propagation characteristics of bone tissue and their relationship with CT imaging results, as well as the potential application of ultrasound navigation in pedicle screw fixation. The study used three bovine spine specimens (BSSs) and five human vertebral allograft bones (HABs) to progressively decrease the thickness of the cancellous bone layer, simulating the process of pedicle screw perforation. Five unfocused miniature ultrasound probes with frequencies of 2.2, 2.5, 3, 12, and 30 MHz were employed for investigating the ultrasonic propagation characteristics of cancellous and cortical bone through ultrasound transmission and backscatter experiments. The CT features of the bone tissue was obtained with the Skyscan 1174 micro-CT scanner (Bruker, Billerica, MA, USA). The experimental results demonstrated that low-frequency (2-3 MHz) ultrasound effectively penetrated the cancellous bone layer up to a depth of approximately 5 mm, with an attenuation coefficient below 10 dB/cm. Conversely, high-frequency (12 MHz) ultrasound exhibited significant signal attenuation in cancellous bone, reaching up to 55.8 dB/cm. The amplitude of the backscattered signal at the cancellous bone interface exhibited a negative correlation with the bone sample thickness (average r=-0.84), meaning that as the thickness of the cancellous bone layer on the cortical bone decreases, the backscattered signal amplitude gradually increases (P<0.05). Upon reaching the cortical bone interface, there was a rapid surge in echo signal amplitude, up to 8 times higher. Meanwhile, the statistical results indicated a significant correlation between the amplitude of the echo signal and the micro-CT scanning results of bone trabecular structure. Theoretically, using multiple ultrasonic probes (≥3) and regions of interest (ROIs) (≥5) has the potential to provide surgeons with early warning signals for pedicle perforation based on three or more successive increases in echo signal amplitude or a sudden substantial increase. The statistical results indicate a significant correlation between the amplitude of the echo signal and the micro-CT scanning results of bone trabeculae, suggesting the potential use of ultrasound as opposed to CT for real-time intraoperative bone navigation.

A usability analysis of augmented reality and haptics for surgical planning.

Proper visualization and interaction with complex anatomical data can improve understanding, allowing for more intuitive surgical planning. The goal of our work was to study what the most intuitive yet practical platforms for interacting with 3D medical data are in the context of surgical planning. We compared planning using a monitor and mouse, a monitor with a haptic device, and an augmented reality (AR) head-mounted display which uses a gesture-based interaction. To determine the most intuitive system, two user studies, one with novices and one with experts, were conducted. The studies involved planning of three scenarios: (1) heart valve repair, (2) hip tumor resection, and (3) pedicle screw placement. Task completion time, NASA Task Load Index and system-specific questionnaires were used for the evaluation. Both novices and experts preferred the AR system for pedicle screw placement. Novices preferred the haptic system for hip tumor planning, while experts preferred the mouse and keyboard. In the case of heart valve planning, novices preferred the AR system but there was no clear preference for experts. Both groups reported that AR provides the best spatial depth perception. The results of the user studies suggest that different surgical cases may benefit from varying interaction and visualization methods. For example, for planning surgeries with implants and instrumentations, mixed reality could provide better 3D spatial perception, whereas using landmarks for delineating specific targets may be more effective using a traditional 2D interface.

Surgical outcomes of robotic-assisted percutaneous fixation for thoracolumbar fractures in patients with ankylosing spondylitis

BackgroundSpinal fractures in patients with ankylosing spondylitis (AS) mainly present as instability, involving all three columns of the spine, and surgical intervention is often considered necessary. However, in AS patients, the significant alterations in bony structure and anatomy result in a lack of identifiable landmarks, which increases the difficulty of pedicle screw implantation. Therefore, we present the clinical outcomes of robotic-assisted percutaneous fixation for thoracolumbar fractures in patients with AS.MethodsA retrospective review was conducted on a series of 12 patients diagnosed with AS. All patients sustained thoracolumbar fractures between October 2018 and October 2022 and underwent posterior robotic-assisted percutaneous fixation procedures. Outcomes of interest included operative time, intra-operative blood loss, complications, duration of hospital stay and fracture union. The clinical outcomes were assessed using the visual analogue scale (VAS) and Oswestry Disability Index (ODI). To investigate the achieved operative correction, pre- and postoperative radiographs in the lateral plane were analyzed by measuring the Cobb angle.ResultsThe 12 patients had a mean age of 62.8 ± 13.0 years and a mean follow-up duration of 32.7 ± 18.9 months. Mean hospital stay duration was 15 ± 8.0 days. The mean operative time was 119.6 ± 32.2 min, and the median blood loss was 50 (50, 250) ml. The VAS value improved from 6.8 ± 0.9 preoperatively to 1.3 ± 1.0 at the final follow-up (P < 0.05). The ODI value improved from 83.6 ± 6.1% preoperatively to 11.8 ± 6.6% at the latest follow-up (P < 0.05). The average Cobb angle changed from 15.2 ± 11.0 pre-operatively to 8.3 ± 7.1 at final follow-up (P < 0.05). Bone healing was consistently achieved, with an average healing time of 6 (5.3, 7.0) months. Of the 108 screws implanted, 2 (1.9%) were improperly positioned. One patient experienced delayed nerve injury after the operation, but the nerve function returned to normal upon discharge.ConclusionPosterior robotic-assisted percutaneous internal fixation can be used as an ideal surgical treatment for thoracolumbar fractures in AS patients. However, while robot-assisted pedicle screw placement can enhance the accuracy of pedicle screw insertion, it should not be relied upon solely.

Treatment of lumbar disc herniation with robot combined with unilateral biportal endoscopic technology: A case report

BACKGROUND This reported procedure combines the orthopedic surgical robot with the unilateral biportal endoscopy-lumbar interbody fusion (UBE-LIF), utilizing the UBE's wide viewing field and operating space to perform minimally invasive decompressive fusion of the lesioned segment, and the orthopedic surgical robot's intelligence and precision to perform percutaneous pedicle screw placement. The advancement of this procedure lies in the superposition of advantages and offsetting disadvantages of the two new technologies, and the maximum effect of treatment is achieved with maximum minimization of invasiveness and precision under the monitoring of imaging instruments to maximize the benefit of patients, and this review reports a case of multiple-segment lumbar decompression and fusion surgery for lumbar disc herniation via robot-assisted UBE for reference. CASE SUMMARY A 44-year-old patient presented to our hospital. Combining various clinical data, we diagnosed the patient with lumbar disc herniation with radiculopathy, lumbar spondylolisthesis, and lumbar spinal stenosis. We developed a surgical plan of "UBE decompression + UBE-LIF + orthopedic surgery robot-assisted percutaneous pedicle screw implantation for internal fixation". The results were satisfactory. CONCLUSION We present an extremely rare case of multiple-segment lumbar decompression and fusion surgery for lumbar disc herniation via robot-assisted UBE and achieved good results. Therefore, the technique is worthy of clinical promotion.

Robotic assisted surgery for the treatment of spinal metastases: A case series

ObjectiveSpinal metastases can significantly affect quality of life in patients with cancer and present complex neurosurgical challenges for surgeons. Surgery with instrumentation is often indicated to alleviate pain, preserve neurological function, and ensure mechanical stability. However, distortions in the bony anatomy due to oncological disease can decrease the accuracy of pedicle screw placement. Robotic-assisted surgery may offer an opportunity to increase screw accuracy and improve navigation of spinal lesions compared to conventional techniques. Therefore, we presented our institutional experience evaluating robotic-assisted surgical fixation for spinal metastases. MethodsPatients undergoing robotic-assisted surgery at a large tertiary care center between January 2019 - January 2023 for the treatment of spinal metastases were identified. Patient characteristics, including demographics, tumor pathology, surgical complications, and post-operative outcomes were extracted. The Gertzbein Robbins classification system (GRS) was used to assess pedicle screw placement accuracy in patients with post-operative computed tomography. ResultsTwenty patients were identified, including 7 females (35 %), with an overall median age of 66 years (range: 39–80 years) and median BMI of 25 kg/m2 (range: 17–34 kg/m2). An average of four spinal levels were instrumented, with metastases located primarily in the thoracic (n=17, 85 %) spine. Common primary tumor types included prostate (n=4), lung (n=2), and plasma cell (n=2) cancers. Most pedicle screws (92 %) were classified as GRS A in patients with postoperative imaging. Post-operative complications were unrelated to the use of the robot, and included pulmonary embolism (n=1), deep vein thrombosis (n=2), and gastric symptoms (n=3). Three patients were readmitted at 30 days, with one reoperation due to tumor recurrence. Four patients were deceased within 6 months of surgery. ConclusionsDespite the inherent high-risk nature of these surgeries, this study underscores the safety and efficacy of robotic-assisted surgery in the management of spinal metastases. Robots can be helpful in ensuring accuracy of pedicle screw placement in patients with metastatic disease.

Flattening the learning curve – Early experience of robotic-assisted pedicle screw placement in spine surgery

Aims and objectivesTo determine accuracy of pedicle screws placed by freehand, fluoroscopy-assistance and robotic-assistance with intraoperative image acquisition, and determine the presence of learning curve in robotic spine surgery in a prospective single centre study. Materials and methodsIn a prospective study, a total of 1120 pedicle screws were placed in Freehand group (n = 175), 1250 screws were placed in fluoroscopy-assisted group (n = 172), and 1225 screws were inserted in Robotic-assisted group(n = 180). Surgical parameters and screw accuracy were analyzed between the three groups. The preoperative plan was overlapped with post operative O-arm scan to determine if the screws were executed as planned. ResultsThe frequency of clinically acceptable screw placement (Gertzbein and Robbins grade A, B) in the Freehand, Fluoroscopy-assisted, and Robotic-assisted groups were 97.7 %, 98.6 %, and 99.34 % respectively. Higher pedicle screw accuracy, and lower blood loss were seen with robotic assistance. There was no significant difference in these parameters between surgeries commencing before and after 2 p.m. We found no statistically significant differences between the planned and executed screw trajectories in robotic assisted group irrespective of surgical experience. ConclusionThe third-generation robotic-assisted pedicle screw placement system, used in conjunction with intraoperative 3D O-arm imaging, consistently lowered blood loss and increased accuracy of pedicle screw placement in the thoracolumbar spine. It also has easy adaptability into spine practice with minimal learning curve.

Biomechanical analysis of adjacent segments after correction surgery for adult idiopathic scoliosis: a finite element analysis

The biomechanical aspects of adjacent segment degeneration after Adult Idiopathic Scoliosis (AdIS) corrective surgery involving postoperative changes in motion and stress of adjacent segments have yet to be investigated. The objective of this study was to evaluate the biomechanical effects of corrective surgery on adjacent segments in adult idiopathic scoliosis by finite element analysis. Based on computed tomography data of the consecutive spine from T1–S1 of a 28-year-old male patient with adult idiopathic scoliosis, a three-dimensional finite element model was established to simulate the biomechanics. Two posterior long-segment fixation and fusion operations were designed: Strategy A, pedicle screws implanted in all segments of both sides, and Strategy B, alternate screws instrumentation on both sides. The range of motion (ROM), Maximum von Mises stress value of intervertebral disc (IVD), and Maximum von Mises stress of the facet joint (FJ) at the fixation adjacent segment were calculated and compared with data of the preoperative AdIS model. Corrective surgery decreased the IVD on the adjacent segments, increased the FJ on the adjacent segments, and decreased the ROM of the adjacent segments. A greater decrease of Maximum von Mises stress was observed on the distal adjacent segment compared with the proximal adjacent segment. The decrease of Maximum von Mises stress and increment of Maximum von Mises stress on adjacent FJ in strategy B was greater than that in strategy A. Under the six operation modes, the change of the Maximum von Mises stress on the adjacent IVD and FJ was significant. The decrease in ROM in the proximal adjacent segment was greater than that of the distal adjacent segment, and the decrease of ROM in strategy A was greater than that in strategy B. This study clarified the biomechanical characteristics of adjacent segments after AdIS corrective surgery, and further biomechanical analysis of two different posterior pedicle screw placement schemes by finite element method. Our study provides a theoretical basis for the pathogenesis, prevention, and treatment of adjacent segment degeneration after corrective surgery for AdIS.

Development of a software system for surgical robots based on multimodal image fusion: study protocol.

Surgical robots are gaining increasing popularity because of their capability to improve the precision of pedicle screw placement. However, current surgical robots rely on unimodal computed tomography (CT) images as baseline images, limiting their visualization to vertebral bone structures and excluding soft tissue structures such as intervertebral discs and nerves. This inherent limitation significantly restricts the applicability of surgical robots. To address this issue and further enhance the safety and accuracy of robot-assisted pedicle screw placement, this study will develop a software system for surgical robots based on multimodal image fusion. Such a system can extend the application range of surgical robots, such as surgical channel establishment, nerve decompression, and other related operations. Initially, imaging data of the patients included in the study are collected. Professional workstations are employed to establish, train, validate, and optimize algorithms for vertebral bone segmentation in CT and magnetic resonance (MR) images, intervertebral disc segmentation in MR images, nerve segmentation in MR images, and registration fusion of CT and MR images. Subsequently, a spine application model containing independent modules for vertebrae, intervertebral discs, and nerves is constructed, and a software system for surgical robots based on multimodal image fusion is designed. Finally, the software system is clinically validated. We will develop a software system based on multimodal image fusion for surgical robots, which can be applied to surgical access establishment, nerve decompression, and other operations not only for robot-assisted nail placement. The development of this software system is important. First, it can improve the accuracy of pedicle screw placement, percutaneous vertebroplasty, percutaneous kyphoplasty, and other surgeries. Second, it can reduce the number of fluoroscopies, shorten the operation time, and reduce surgical complications. In addition, it would be helpful to expand the application range of surgical robots by providing key imaging data for surgical robots to realize surgical channel establishment, nerve decompression, and other operations.