Accuracy of Current Techniques for Placement of Pedicle Screws in the Spine: A Comprehensive Systematic Review and Meta-Analysis of 51,161 Screws

Characterizing the complication profile of spinal robotic systems: A MAUDE analysis of device failures and associated complications by device manufacturer and brand name

INTRODUCTION

Pedicle screw placement in spinal surgery has evolved to incorporate increased use of technology for both preoperative planning and intraoperative guidance. In recent years, robotic guidance has been used to increase the precision, accuracy, and overall patient safety of spinal column fixation via screw placement. Within this context, the present study aims to quantify and classify complications of spinal robotic devices using a nationally representative database.

METHODS

The Manufacturer and User Facility Device Experience (MAUDE) was queried for adverse events involving the most widely used spinal robotic devices from inception to November 3rd, 2023. Entries were tabulated by assigning categorical variables based on event information.

RESULTS

The query yielded 339 unique robotic failure events. The most frequent complications in robotic-assisted spinal surgeries were imprecision (73.6%), software errors (13.7%), and damaged or missing screws (4.9%). Most reported events occurred intraoperatively after the initial incision (78.5%) [compared to preoperatively or postoperatively]. The Mazor X™ system was the most represented spinal robotic platform in terms of complications, accounting for 71.6% of reported robotic failure events. Most reported errors were resolved intraoperatively or continued through the employment of alternative imaging methods and, overall, had minimal clinical significance. With respect to robot-assisted pedicle screw placement, medial breaches were 1.7x more common than lateral breaches across all robotic systems. Finally, regarding the impact of device failures on perioperative timing, we found that 10.3% of adverse events resulted in delays greater than 1 h.

CONCLUSION

Ultimately, imprecision and unresponsive software were found to be two of the most frequent complications of robot-assisted spine surgery. Though most reported errors were circumvented intraoperatively through conventional, non-robotic imaging/guidance methods, 10.3% of adverse events resulted in procedural delays of greater than 1 h.

Radiation Exposure and Dose Estimates of Robot-Guided Versus Fluoroscopy-Guided Spinal Fusion: A Meta-Analysis of Randomized Controlled Trials

STUDY DESIGN

Systematic review and meta-analysis.

SUMMARY OF BACKGROUND DATA

Robot-guided (RG) pedicle screw placement offers several advantages over fluoroscopy-guided (FG) surgery to patients undergoing spinal fusion. Radiation exposure and detrimental risks associated with RG surgery are poorly described in the literature.

OBJECTIVES

We perform a systematic review and meta-analysis of randomized controlled trials comparing RG to FG spinal fusion to assess radiation exposure to patients and clinicians.

METHODS

MEDLINE, Embase, Web of Science, and Cochrane Central were systematically queried. Inclusion was restricted to RCTs in adults. Version 2 of the Cochrane risk-of-bias tool for RCTs (RoB 2) was used to evaluate risk of bias and quality was appraised using the GRADE assessment tool. Continuous data were pooled across trials with inverse variance weighting to mean difference (MD) and dichotomous data were pooled with Mantel-Haenszel weighting to odds ratio (OR) with corresponding 95% CI.

RESULTS

A total of 1042 patients (RG: 651; FG: 391) from 8 RCTs were included. Radiation time was reduced in the RG group by 39.6% (MD: -25.65 seconds, 95% CI: -51.07 to -0.22) with an estimated anteroposterior and lateral dose-area product in the RG group measuring 123.85±73.12 and 241.08±142.33 cGycm2, respectively. Estimated cancer risk and detrimental hereditary disorder risk were reduced by 40.2% in the RG group (3.60×10-5±2.12×10-5 and 1.31×10-6±7.72×10-7, respectively). Intraoperative bleeding volume was reduced in the RG group (MD: -61.52 mL, 95% CI: -100.16 to -22.87, P=0.002, I2=48%). However, surgical duration was significantly higher in the RG group (MD: 12.01 min, 95% CI: 1.63-22.39). Pedicle screw accuracy and length of hospital stay differences were not significant.

CONCLUSIONS

Radiation exposure to patients undergoing spinal fusion is lower in RG surgery compared with FG surgery. These findings can be supported with long-term studies that better characterize radiation dosages associated with these procedures.

LEVEL OF EVIDENCE

Level I.

Percutaneous pedicle screw placement with a mini-open decompression versus open surgery in the treatment of lumbar spondylolisthesis: one-year results of a randomised controlled trial

PURPOSE

Symptomatic lumbar spondylolisthesis is usually treated with fusion surgery when conservative methods fail. However, traditional open decompression and fusion involves a large skin incision and muscle detachment. Therefore, minimally invasive techniques have been developed to reduce tissue damage, potentially leading to less postoperative pain and earlier resumption of activities. The purpose of this study was to compare percutaneous versus open pedicle screw placement in patients receiving lumbar midline decompression due to symptomatic lumbar spondylolisthesis focusing on short-term low back pain.

METHODS

A randomised controlled trial was conducted in 2 Dutch hospital from 2015 to 2020. Participants with spondylolytic or degenerative lumbar spondylolisthesis were randomised into percutaneous pedicle screw placement with a mini-open decompression (mini-open), or conventional open surgery with instrumented fusion (open). The primary outcome measure was short-term low back pain after 2 weeks, measured by a visual analogue scale. Leg pain, disability and quality of life were recorded at 2 and 6 weeks, 3 and 6 months and 1 year. Surgical variables, including complications, were recorded. Analyses were performed in the intention-to-treat population.

RESULTS

In total, 169 participants were included and randomised to mini-open (n = 81) or standard open surgery (n = 88). No statistically or clinically significant differences were found between groups in terms of primary or secondary outcomes. Surgery duration, blood loss, hospital stay, and complications were also similar between groups.

CONCLUSIONS

This study detected no difference in outcome between mini-open compared to open surgery in patients with spondylolisthesis. The hypothetical advantage of reduced short-term low back pain, less blood loss and better clinical outcome could not be confirmed.

Computer tomography-assisted 3-dimensional navigation in spine surgery: a narrative review on safety, accuracy, efficacy and reduction of complications

The computed tomography-assisted 3D navigation system is a useful tool for spinal surgeons, enabling them to enhance the effectiveness and safety of surgical procedures by providing real-time three-dimensional information during decompression, resection, and instrumentation. Specific advantages of this navigation system include precise pedicle screw placement, the capability for immediate intraoperative correction, and execution of minimally invasive surgeries with reduced radiation exposure for the surgical team. Noteworthy disadvantages of this system are the relatively high implementation costs, the need for specific training, and limited accessibility to outpatient surgery centers. Currently, spinal navigation systems are constantly being upgraded with additional innovations, such as integration with robotics and improvement of the existing tools, which will ultimately lead to a better quality of life for patients and an improved experience for surgeons.

Evaluation of the safety, radiographic and resident training results of thoracic pedicle screws placement using resection of the transverse process

OBJECTIVE

This study aimed at the evaluation and assessment of a simple method, the transverse process resection (TPR) technique, for freehand thoracic pedicle screw placement and the learning curve for trainee surgeons.

METHODS

In the TPR technique, the tip of the thoracic transverse process (TP) is removed to create an entry point in the cancellous bone of the TP, and the thoracic pedicle is cannulated from the TP. We retrospectively evaluated the safety and radiographic results of the TPR technique and compared with that of conventional pedicle screws. The training performance of seven neurosurgical residents with TPR techniques were evaluated.

RESULTS

Among 46 patients, a total of 322 thoracic screws were analyzed, including 178 screws placed using the TPR technique and 144 screws using the conventional straight-forward (SF) technique. TPR screws had greater medial angulations in all levels from T2 to T12 compared to SF screws (p < 0.001). The incidence of pedicle breach was lower in the TPR screws compared to SF screws (6.2% vs. 21.5%, p < 0.001), especially for screws placed by residents (6.7% vs. 29.6%, p < 0.001). Residents had improved performance following a cadaveric training course on the TPR technique (p = 0.001).

CONCLUSION

This study demonstrated the safety of the TPR technique for thoracic pedicle screw placement and its short learning curve for trainee surgeons.

Advancing spine surgery: Evaluating the potential for full robotic automation

Introduction

The use of robotic systems in spine surgery is expanding, with growing interest in the potential for full automation. This review explores current robotic technologies, their limitations, and future automation possibilities, focusing on technical and practical aspects.

Research question

What are the current capabilities and limitations of robotic systems in spine surgery, and how might advancements in tracking technologies facilitate a transition toward greater automation?

Material and methods

A narrative review of literature on robotic spine surgery systems was conducted, analyzing benefits, accuracy, limitations, and innovations necessary for full automation. Focus was placed on trajectory-guiding technologies, such as optical tracking and alternative tracking methods.

Results

Current robotic systems (e.g., Cirq®, Mazor X™, ExcelsiusGPS™) assist in trajectory guidance but lack autonomy. Optical tracking systems present challenges, such as obstruction vulnerability and inaccuracies in complex constructs. Conversely, encoder-based tracking demonstrated superior accuracy, offering a promising pathway toward increased automation. The potential advantages of robotics over conventional navigation, including their nature and clinical relevance, remain a topic of active discussion. However, the inherent complexity of spine surgery and the critical role of human decision-making remain substantial barriers.

Discussion and conclusion

While full automation in robotic spine surgery is not yet attainable, advancements in tracking technologies point to a future of enhanced robot-surgeon collaboration, which could optimize clinical outcomes and improve procedural safety.

[Navigated and minimally invasive screw osteosynthesis of a talus fracture]

OBJECTIVE OF SURGERY

The aim of this surgery is to safeguard the multifragmentary and nondisplaced talus fracture (body and neck) against secondary dislocation in a navigated and minimally invasive manner using screw osteosynthesis.

INDICATIONS

Due to the young age of the patient in the presented case and the risk of a possible secondary dislocation, the decision was made in favor of surgical treatment.

CONTRAINDICATIONS

Soft tissue swelling, wound infections and allergies to the osteosynthesis material.

SURGICAL TECHNIQUE

The video is available online (in English) and shows the individual surgical steps in detail. Preoperative computed tomography (CT) imaging and screw planning. Attachment of the reference array. 1) Cone beam CT (CBCT) scan, image fusion and fusion control. Planning of the minimally invasive skin incisions. Skin incision, navigated drilling and insertion of the K‑wires. 2) CBCT scan and position check of the K‑wires, fine adjustment if necessary. Insertion of the screws. 3) CBCT scan with subsequent position check of the screws, retightening of the screws if necessary. Performed in the Robotic Suite (Brainlab, Munich, Germany) using the following elements: navigation unit curve navigation system, movable robotic 3D CBCT, "Loop-X" and wall monitor "BUZZ".

FOLLOW-UP

Postoperative X‑ray and CT to control the position of the implants. Partial weight-bearing of the foot with 10 kg sole contact for 6 weeks. Physiotherapy with active and passive joint mobilization. Thrombosis prophylaxis with enoxaparin sodium. Optional implant removal after approximately 1 year.

EVIDENCE

Navigated operations are routine, so far mainly in the area of the spine. This article shows that navigated extremity surgery can be successfully performed in hybrid operating theaters.

Comparing Three-dimensional and Two-dimensional Preoperative Planning for Lumbar Transpedicular Screw Placement: A Retrospective Study

BACKGROUND

 Transpedicular screw (TPS) misplacement is still a nightmare for spine surgeons. Preoperative planning is one of the methods that a surgeon could use to minimize this complication. This study aims to compare the efficacy of three-dimensional (3D) and two-dimensional (2D) preoperative planning in posterior lumbar TPSs placement performed using the freehand technique.

PATIENTS AND METHODS

 Patients who underwent posterior TPSs placement for degenerative lumbar spondylolisthesis or spinal stenosis using the freehand technique between November 2021 and October 2022 were evaluated retrospectively. In total, 33 and 30 patients who met the inclusion criteria were consecutively operated on with preoperative 2D and 3D planning, respectively. The patients were divided into the 2D preoperative planning group (2DG) and 3D preoperative planning group (3DG) and the two groups were compared.

RESULTS

 Sixty-three patients were operated during the study period. There was no significant difference between the groups regarding blood transfusion, operation time, and radiation exposure. Although the accuracy of TPSs positioning was 94.2 and 96.5% in the 2DG and 3DG, respectively, the difference between the groups was not statistically significant. The upper facet joint violation rate was 12.8% (n = 20) in the 2DG versus 3.5% (n = 5) in the 3DG (p = 0.006). All L4 TPSs were inserted with their standard entry points without any modification (p < 0.0001; relative/risk ratio = 0.64). The modification rate was higher in L1, L2, and L5 TPSs (p < 0.0001; χ 2 = 24.7).

CONCLUSION

 For patients with degenerative lumbar diseases, 3D preoperative planning in posterior lumbar instrumentation surgeries performed with the freehand technique decreased the upper facet joint violation rate.

Domain adaptation strategies for 3D reconstruction of the lumbar spine using real fluoroscopy data

In this study, we address critical barriers hindering the widespread adoption of surgical navigation in orthopedic surgeries due to limitations such as time constraints, cost implications, radiation concerns, and integration within the surgical workflow. Recently, our work X23D showed an approach for generating 3D anatomical models of the spine from only a few intraoperative fluoroscopic images. This approach negates the need for conventional registration-based surgical navigation by creating a direct intraoperative 3D reconstruction of the anatomy. Despite these strides, the practical application of X23D has been limited by a significant domain gap between synthetic training data and real intraoperative images. In response, we devised a novel data collection protocol to assemble a paired dataset consisting of synthetic and real fluoroscopic images captured from identical perspectives. Leveraging this unique dataset, we refined our deep learning model through transfer learning, effectively bridging the domain gap between synthetic and real X-ray data. We introduce an innovative approach combining style transfer with the curated paired dataset. This method transforms real X-ray images into the synthetic domain, enabling the in-silico-trained X23D model to achieve high accuracy in real-world settings. Our results demonstrated that the refined model can rapidly generate accurate 3D reconstructions of the entire lumbar spine from as few as three intraoperative fluoroscopic shots. The enhanced model reached a sufficient accuracy, achieving an 84% F1 score, equating to the benchmark set solely by synthetic data in previous research. Moreover, with an impressive computational time of just 81.1 ms, our approach offers real-time capabilities, vital for successful integration into active surgical procedures. By investigating optimal imaging setups and view angle dependencies, we have further validated the practicality and reliability of our system in a clinical environment. Our research represents a promising advancement in intraoperative 3D reconstruction. This innovation has the potential to enhance intraoperative surgical planning, navigation, and surgical robotics.

Risk of neurologic deficit in medially breached pedicle screws assessed by computed tomography: a systematic review

Pedicle screws are commonly used for vertebral instrumentation, and a postoperative computed tomography (CT) scan is used to evaluate their position within the pedicle. Medial pedicle screw breaching occurs in 20%-40% of cases. This study investigated the correlation between radiographically evident medial breaching and the incidence of nerve injury, shedding light on the clinical implications. A literature search was conducted on biomedical databases regarding neurologic deficits associated with medially breached pedicle screws with pre-defined inclusion and exclusion criteria. The methodology of the included studies was analyzed, and a systematic review and meta-analysis were performed to investigate the correlation between medial breach on axial CT and clinical neurologic deficits. Our study included thirteen articles. Medial breaches <2 mm caused no neurologic deficit. Medial breaches of 2-4 mm increased the risk of neurologic deficit by 83%, with a risk ratio of 0.17. Breaches exceeding 4 mm increased the risk by 90%, with a risk ratio of 0.1, and were associated with radiculopathy or muscle weakness in 25%-100% of cases. Medial pedicle screw breaches <2 mm are safe, carrying no risk of neurologic injury. Breaches exceeding ≥2 mm significantly increase this risk. For patients experiencing new neurologic deficit (sensory or motor) after pedicle screw instrumentation, particularly in lumbar vertebrae, a postoperative axial CT scan is recommended to identify breaches exceeding 2 mm as the potential cause of neurologic deficit.

Effect of pedicle screw misplacement on the pull-out strength using personalized finite element modeling

Intraoperative misplacement of vertebral pedicle screws is prevalent. While a pedicle screw misplacement of up to 4 mm is often considered safe by clinical standards, this may reduce the pull-out strength thereby increasing the risk of postoperative screw loosening. This study aimed to compare the pull-out strength of ideally-placed and misplaced pedicle screws via personalized finite element (FE) modeling simulations. Three-dimensional FE models to simulate pull-out tests of pedicle screws were constructed. Vertebral geometries and material properties were both determined based on computed tomography images from lumbar spine (L1-L5) of a 29-year-old healthy male individual. Pedicle screws were bilaterally placed under four conditions: ideal placement (no cortex perforation) as well as minor medial, minor lateral, and severe lateral misplacements causing cortex perforations. Minor and severe misplacements corresponded to, respectively, grades C and D of the Gertzbein classification. After meshing and voxel-based vertebral material assignments based on two distinct mappings from literature, pull-out strengths were estimated by considering a strain-based damage model to accurately simulate bone fractures. Results indicated that the mean of FE-predicted pull-out forces for ideally-placed screws (1583 and 2412 N for material mappings 1 and 2, respectively) was within the range of previous experimental data (ranging from 1016 to 2443 N) thus confirming the model validation. The mean of all pull-out forces for each misplaced screw group was significantly smaller (p < 0.05) than that of the ideally-placed screws, e.g., 20 % for minor medial, 22 % for minor lateral, and 37 % for severe lateral misplacements. These findings indicated that even clinically-acceptable screw misplacements (up to 4 mm) could significantly reduce the pull-out strengths of pedicle screws thus imposing higher risk of postoperative screw loosening. To avoid these common screw misplacements, the use of advanced approaches for pedicle screw placements appears to be imperative.

Is minimally invasive surgery a game changer in spinal surgery?

Minimally invasive spine surgery (MISS) has revolutionized the treatment of spinal disorders over the past few decades. This review provides an in-depth analysis of MISS techniques, technologies, outcomes, and future directions. The evolution of MISS techniques-including tubular retractor systems, percutaneous pedicle screw fixation, minimally invasive transforaminal lumbar interbody fusion, lateral lumbar interbody fusion, and endoscopic spine surgery-has expanded the scope of treatable spinal pathologies while minimizing tissue trauma. Technological advancements such as intraoperative navigation, robotics, and augmented reality applications have enhanced precision and capabilities. Clinical evidence supports the efficacy and safety of MISS techniques for various spinal pathologies, demonstrating comparable or superior outcomes to traditional open approaches with reduced tissue trauma, blood loss, and hospital stays. Cost-effectiveness analyses also favor MISS over open techniques. Future directions in MISS include expanding indications, integrating artificial intelligence and machine learning, advancing tissue engineering and biologics, and refining robotic and augmented reality applications. As MISS continues to evolve, it is poised to play an increasingly important role in the treatment of spinal disorders, offering improved patient outcomes with reduced morbidity. However, ongoing rigorous evaluation of new techniques and technologies is crucial to balance potential benefits with associated risks and costs.

Hybrid-3D robotic suite in spine and trauma surgery - experiences in 210 patients

BACKGROUND

In modern Hybrid ORs, the synergies of navigation and robotics are assumed to contribute to the optimisation of the treatment in trauma, orthopaedic and spine surgery. Despite promising evidence in the area of navigation and robotics, previous publications have not definitively proven the potential benefits. Therefore, the aim of this retrospective study was to evaluate the potential benefit and clinical outcome of patients treated in a fully equipped 3D-Navigation Hybrid OR.

METHODS

Prospective data was collected (March 2022- March 2024) after implementation of a fully equipped 3D-Navigation Hybrid OR ("Robotic Suite") in the authors level 1 trauma centre. The OR includes a navigation unit, a cone beam CT (CBCT), a robotic arm and mixed reality glasses. Surgeries with different indications of the spine, the pelvis (pelvic ring and acetabulum) and the extremities were performed. Spinal and non-spinal screws were inserted. The collected data was analysed retrospectively. Pedicle screw accuracy was graded according to the Gertzbein and Robbins (GR) classification.

RESULTS

A total of n = 210 patients (118 m:92f) were treated in our 3D-Navigation Hybrid OR, with 1171 screws inserted. Among these patients, 23 patients (11.0%) arrived at the hospital via the trauma room with an average Injury Severity Score (ISS) of 25.7. There were 1035 (88.4%) spinal screws inserted at an accuracy rate of 98.7% (CI95%: 98.1-99.4%; 911 GR-A & 111 GR-B screws). The number of non-spinal screws were 136 (11.6%) with an accuracy rate of 99.3% (CI95%: 97.8-100.0%; 135 correctly placed screws). This resulted in an overall accuracy rate of 98.8% (CI95%: 98.2-99.4%). The robotic arm was used in 152 cases (72.4%), minimally invasive surgery (MIS) was performed in 139 cases (66.2%) and wound infection occurred in 4 cases (1,9%). Overall, no revisions were needed.

CONCLUSION

By extending the scope of application, this study showed that interventions in a fully equipped 3D-Navigation Hybrid OR can be successfully performed not only on the spine, but also on the pelvis and extremities. In trauma, orthopaedics and spinal surgery, navigation and robotics can be used to perform operations with a high degree of precision, increased safety, reduced radiation exposure for the OR-team and a very low complication rate.

Accurate placement of thoracolumbar pedicle screws using a handheld iOS-based navigation device: a prospective intra-patient agreement study

BACKGROUND

Accurate pedicle screw placement is a challenge with reported misplacement rates of 10% and higher. A handheld navigation device (HND) may provide accuracy equal to CT-based navigation (CT-Nav) but without the cost and complexity.

OBJECTIVE

To study the accuracy of a handheld navigation device for pedicle screw placement.

STUDY DESIGN

This prospective cross-sectional study with consistently applied reference standard enrolled 20 patients undergoing 92 pedicle screw placements.

PATIENTS

Patients who underwent pedicle screw placement between May 2022 and September 2022.

OUTCOME MEASURES

Pedicle screw placement accuracy per Gertzbein-Robbins.

METHODS

Once the screw pilot hole was established, the proposed trajectory of the HND was compared with that proposed by CT-Nav. Postoperatively, screw accuracy was graded according to Gertzbein-Robbins by a blinded radiologist based on CT scans. Accuracy was compared between the two systems and published control for fluoroscopy assisted and CT-Nav placement using Bayesian posterior distribution.

RESULTS

The trajectory proposed by the HND and CT-Nav were in agreement in 98.9% (95% Exact CI; 94.09%-99.97%). The HND accuracy was 98.9% with 91 screws rated "A" and 1 rated "C". Noninferiority to fluoroscopic placement was achieved because the one-sided normal-approximation 95% CI Lower Bound (LB) of 95.3% is greater than the Performance Goal (PG) of 83.4%. Posthoc analysis demonstrated that the probability of superiority of the HND relative to the historical accuracy rate of 91.5% for fluoroscopy assisted procedures is >0.999 and that the HND's accuracy rate is within 4.5% of CT-Nav of 95.5% is >0.999. No adverse events or intra-operative complications associated with HND were observed. There was 1 (1.1%) intra-operative repositioning and no reoperations for any reason.

CONCLUSIONS

The accuracy rate of the HND was 98.9%, and the proposed trajectory matched with CT-Nav in 98.9% of the time. This is superior to the historical published accuracy rate for fluoroscopy-assisted procedures and equivalent to the historical published accuracy rate for CT-Nav.

CLINICAL TRIAL REGISTRATION NUMBER

Dutch trial register NL74268.058.20.

Top 100 Most Cited Articles on Intraoperative Image-Guided Navigation in Spine Surgery

Navigation technologies have become essential in spine surgery over the last decade, offering precise procedures and minimizing risks. To the best of our knowledge, this is the first bibliometric analysis on this topic, providing insights and trends on topics, authors, and journals. The study identifies and analyzes the 100 most cited articles related to navigation in spine surgery. A systematic search was performed in Scopus and Google Scholar to identify all articles related to navigation in spine surgery (38,057 articles). The 100 most cited were analyzed for citations, titles, abstracts, authors, affiliations, keywords, country and institute of origin, year of publication, and level of evidence. The search was conducted in October 2023. The 100 most cited articles were published between 1995 and 2019, with 2010 to 2019 being the most prolific decade (46%). The most cited article had 733 citations, and the paper with the most citations per year averaged 59.27 citations/year. The Spine Journal had the most articles (34%). The United States contributed the most articles (39%). Most publications were clinical research and reviews (94%), with an overall evidence grade of IV-V (63%). A positive trend was noted in the last decade for incorporating augmented reality. This bibliometric analysis offers valuable insights and trends in spine surgery navigation literature. The findings indicate that technological advancements have led to more articles with higher levels of evidence. These pivotal articles shape evidence-based medicine, future surgeons, and industry improvements in navigated spine surgery.

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

OBJECTIVE

Spinal 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.

METHODS

Patients 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.

RESULTS

Twenty 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.

CONCLUSIONS

Despite 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.

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

BACKGROUND

As 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.

OBJECTIVE

We aimed to investigate whether the RA TLIF is superior to FG TLIF in the treatment of lumbar degenerative disease.

METHODS

We 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.

RESULTS

Our 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.

CONCLUSION

In 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 REGISTRATION

PROSPERO CRD42023441600.

Accurate Placement and Revisions for Cervical Pedicle Screws Placed With or Without Navigation: A Systematic Review and Meta-Analysis

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVES

To evaluate the accuracy of placement for cervical pedicle screws with and without the use of spinal navigation.

METHODS

A structured search was conducted in electronic databases without any language or date restrictions. Eligible studies reported the proportion of accurately placed cervical pedicle screws measured on intraoperative or postoperative 3D imaging, and reported whether intraoperative navigation was used during screw placement. Randomized Studies (MINORS) criteria were used to evaluate the methodological quality of how accuracy was assessed for cervical pedicle screws.

RESULTS

After screening and critical appraisal, 4697 cervical pedicle screws from 18 studies were included in the meta-analysis. The pooled proportion for cervical pedicle screws with a breach up to 2 mm was 94% for navigated screws and did not differ from the pooled proportion for non-navigated screws (96%). The pooled proportion for cervical pedicle screws placed completely in the pedicle was 76% for navigated screws and did not differ from the pooled proportion for non-navigated screws (82%). Intraoperative screw reposition rates and screw revision rates as a result of postoperative imaging also did not differ between navigated and non-navigated screw placement.

CONCLUSIONS

This systematic review and meta-analysis found that the use of spinal navigation systems does not significantly improve the accuracy of placement of cervical pedicle screws compared to screws placed without navigation. Future studies evaluating intraoperative navigation for cervical pedicle screw placement should focus on the learning curve, postoperative complications, and the complexity of surgical cases.

[Precision and safety of positioning pedicle screws in the thoracic and lumbar spine using a hand-guided aiming sleeve : A CT control study]

BACKGROUND

For the implantation of pedicle screws, navigation-supported systems are nowadays used more and more to avoid screw misalignment by making the direction of the screw more predictable.

OBJECTIVE

Examination of the precision after instrumentation of the pedicle screw with the hand-guided aiming sleeve. The aim was to verify that the implementation of the pedicle screws is plannable and precise by using 2D X‑ray only.

METHOD

This retrospective study analyzed 27 consecutive trauma patients (17-84 years, 13f/14m) with vertebral body fractures. The position and precision of 108 screws, implanted using the hand-guided aiming sleeve was investigated. To determine the position the actual course of the screws was examined using the postoperative 3D CT data set (GE Optima 540, General Electric Company Boston, MA, USA; slice thickness 1.25 mm). The screws were then compared to the previously defined ideal position of the tip of the screw. In addition to the absolute and relative deviation from the ideal target point, the convergence angle and the parallelism to the cover plate were determined.

RESULTS

Of 108 implanted pedicle screws, 90 (83%) were within target. The remaining 18 (17%) represented a clinically irrelevant screw deviation: A lateral deviation was found in 17 pedicle screws (16%) and a medial deviation in 1 (1%). The average deviation from the ideal target point in the vertebral body was 2.3 mm ventrally with a standard deviation of ± 2.3 mm. No screw misalignment or pedicle perforation was found.

CONCLUSION

The transcutaneous implantation of pedicle screws with a hand-guided aiming sleeve in the thoracic and lumbar spine represents a safe and precise procedure. The risk of misalignment needing a revision is lower compared to other methods of navigated screw implantation reported in the literature [1-6]. A CT-based preliminary planning is not necessary. The method is economical, special technical equipment is not required.

Intraoperative anteroposterior and oblique fluoroscopic views for detection of mediolateral pedicle screw misplacement in the lumbar spine: a randomized cadaveric study

BACKGROUD CONTEXT

Pedicle screws are commonly used for posterior fixation of the lumbar spine. Inaccuracy of screw placement can lead to disastrous complications.

PURPOSE

As fluoroscopic assisted pedicle screw instrumentation is the most frequently used technique, the aim of this study was to assess the specificity, sensitivity and accuracy of intraoperative fluoroscopy to detect mediolateral screw malpositioning. We also analyzed whether the addition of an oblique view could improve these parameters.

STUDY DESIGN

On 12 human cadavers, 138 pedicle screws were placed intentionally either with 0 to 2 mm (75 screws), with 2 to 4 mm (six medial and 12 lateral screws) and with >4 mm (22 medial and 23 lateral screws) breach of the pedicle from Th12 to L5.

METHODS

Three experienced spine surgeons evaluated the screw positioning in fluoroscopic AP views and 4 weeks later in AP views and additional oblique views. The surgeons' interpretation was compared with the effective screw position on postoperative CT scans.

RESULTS

Pedicle breaches greater than 2 mm were detected in 68% with AP views and in 67% with additional oblique views (p=.742). The specificity of AP views was 0.86 and 0.93 with additional oblique views (p=<.01). The accuracy was 0.78 with AP views and 0.81 with AP + oblique views (p=.114). There was a substantial inter-reader agreement (Fleiss's kappa: 0.632).

CONCLUSIONS

Fluoroscopic screening of pedicle screw misplacement has a limited sensitivity. Adding an oblique view improves specificity but not sensitivity and accuracy in detecting screw malpositions.

CLINICAL SIGNIFICANCE

When in doubt of a screw malpositioning, other modalities than a fluoroscopic assisted pedicle screw instrumentation such as intraoperative CT imaging or an intraoperative exploration of the screw trajectory must be evaluated.

Effects of Augmented Reality on Thoracolumbar Pedicle Screw Instrumentation Across Different Levels of Surgical Experience

OBJECTIVE

Augmented reality (AR) is an emerging technology that may accelerate skill acquisition and improve accuracy of thoracolumbar pedicle screw placements. We aimed to quantify the relative assistance of AR compared with freehand (FH) pedicle screw accuracy across different surgical experience levels.

METHODS

A spine fellowship-trained and board-certified attending neurosurgeon, postgraduate year 4 neurosurgery resident, and second-year medical student placed 32 FH and 32 AR-assisted thoracolumbar pedicle screws in 3 cadavers. A cableless, voice-activated AR system was paired with a headset. Accuracy was assessed using χ2 analysis and the Gertzbein-Robbins scale. Angular error, distance error, and time per pedicle screw were collected and compared.

RESULTS

The attending neurosurgeon had 91.6% (11/12) clinically acceptable (Gertzbein-Robbins scale A or B) insertion in both FH and AR groups; the resident neurosurgeon had 100% (9/9) FH and AR in both cases; the medical student had 72.3% (8/11) FH accuracy and 81.8% (9/11) AR accuracy. The medical student displayed significantly lower ideal (Gertzbein-Robbins scale A) FH accuracy compared with the resident neurosurgeon (P = 0.017) and attending neurosurgeon (P = 0.005), but no difference when using AR. FH screw placement was faster by both the attending neurosurgeon (median 46 seconds vs. 94.5 seconds, P = 0.0047) and the neurosurgery resident neurosurgeon (median 144 seconds vs. 140 seconds, P = 0.05). Total clinically acceptable AR and FH accuracy was 90.6% (29/32) and 87.5% (28/32), respectively (P = 0.69).

CONCLUSIONS

AR screw placement allowed an inexperienced medical student to double their accuracy in 1 training session. With subsequent iterations, this promising technology could serve as an important tool for surgical training.

Fiber-Optic Pedicle Probes to Advance Spine Surgery through Diffuse Reflectance Spectroscopy

Diffuse Reflectance Spectroscopy (DRS) can provide tissue feedback for pedicle screw placement in spine surgery, yet the integration of fiber optics into the tip of the pedicle probe, a device used to pierce through bone, is challenging, since the optical probing depth and signal-to-noise ratio (SNR) are affected negatively compared to those of a blunt DRS probe. Through Monte Carlo simulations and optical phantom experiments, we show how differences in the shape of the instrument tip influence the acquired spectrum. Our findings demonstrate that a single bevel with an angle of 30∘ offers a solution to anticipate cortical breaches during pedicle screw placement. Compared to a blunt probe, the optical probing depth and SNR of a cone tip are reduced by 50%. The single bevel tip excels with 75% of the optical probing depth and a SNR remaining at approximately ⅔, facilitating the construction of a surgical instrument with integrated DRS.

Automatic registration with continuous pose updates for marker-less surgical navigation in spine surgery

Established surgical navigation systems for pedicle screw placement have been proven to be accurate, but still reveal limitations in registration or surgical guidance. Registration of preoperative data to the intraoperative anatomy remains a time-consuming, error-prone task that includes exposure to harmful radiation. Surgical guidance through conventional displays has well-known drawbacks, as information cannot be presented in-situ and from the surgeon's perspective. Consequently, radiation-free and more automatic registration methods with subsequent surgeon-centric navigation feedback are desirable. In this work, we present a marker-less approach that automatically solves the registration problem for lumbar spinal fusion surgery in a radiation-free manner. A deep neural network was trained to segment the lumbar spine and simultaneously predict its orientation, yielding an initial pose for preoperative models, which then is refined for each vertebra individually and updated in real-time with GPU acceleration while handling surgeon occlusions. An intuitive surgical guidance is provided thanks to the integration into an augmented reality based navigation system. The registration method was verified on a public dataset with a median of 100% successful registrations, a median target registration error of 2.7 mm, a median screw trajectory error of 1.6°and a median screw entry point error of 2.3 mm. Additionally, the whole pipeline was validated in an ex-vivo surgery, yielding a 100% screw accuracy and a median target registration error of 1.0 mm. Our results meet clinical demands and emphasize the potential of RGB-D data for fully automatic registration approaches in combination with augmented reality guidance.

Decreasing the Pedicle Screw Misplacement Rate in the Thoracic Spine With Robot-guided Navigation

STUDY DESIGN

A retrospective chart review.

OBJECTIVE

The aim of this study was to evaluate the screw accuracy of thoracic pedicle screws placed with a robot-guided navigation system.

SUMMARY OF BACKGROUND DATA

Thoracic pedicles are smaller in diameter than lumbar pedicles, making pedicle screw placement difficult. Misplaced pedicle screws may present complications including decreased construct stability, and increased risks of neurological deficits and blood vessel perforation. There is a dearth of knowledge on thoracic pedicle screw accuracy placed with a robot.

MATERIALS AND METHODS

A retrospective analysis of the robot-assisted placement of thoracic pedicle screws was performed. Preoperative and postoperative computed tomography (CT) scans of the implanted thoracic screws were collected to assess screw placement accuracy, pedicle breadth, and placement deviations. A CT-based Gertzbein and Robbins System was used to classify pedicle screw accuracy in 2 mm increments. A custom image overlay software was used to determine the deviations between the preoperatively planned trajectory of pedicle screws and final placement at screw entry (tail), and tip in addition to the angular deviation.

RESULTS

Seventy-five thoracic pedicle screws were implanted by navigated robotic guidance in 17 patients, only 1.3% (1/75) were repositioned intraoperatively. Average patient age and body mass index were 57.5 years and 25.9 kg/m 2 , respectively, with 52.9% female patients. Surgery diagnoses were degenerative disk disease (47.1%) and adjacent segment disease (17.6%). There were zero complications, with no returns to the operating room. According to the CT-based Gertzbein and Robbins pedicle screw breach classification system, 93.3% (70/75) screws were grade A or B, 6.6% (5/75) were grade C, and 0% were grade D or E. The average deviation from the preoperative plan to actual final placement was 1.8±1.3 mm for the screw tip, 1.6±0.9 mm for the tail, and 2.1±1.5 degrees of angulation.

CONCLUSIONS

The current investigation found a 93.3% accuracy of pedicle screw placement in the thoracic spine. Navigated robot assistance is a useful system for placing screws in the smaller pedicles of the thoracic spine.

LEVEL OF EVIDENCE

Level III-retrospective nonexperimental study.

Design of an ultrasound-emitting drill guide for freehand pedicle screw navigation

BACKGROUND

Accurate pedicle screw placement in spinal surgery is critical as inaccuracies can lead to morbidity and suboptimal outcomes. Navigation and robotics have reduced malplacement rates, but their adoption is limited by high costs, learning curves, surgical time, and radiation. The authors propose an ultrasound-emitting and self-localising drill guide for precise screw placement that overcomes the limitations of current techniques.

MATERIALS AND METHODS

The preliminary configuration analysis involves systematically varying design parameters and assessing localization performance using lumbar spine MRI based simulations. The authors evaluate localization techniques based on accuracy and optimization capture range.

RESULTS

Results suggest that feasible designs can accurately estimate position. A promising design features a 5 mm radius cannula with ten 35mm-long ultrasound strips, 32 elements per strip, and a fanned-out emission profile. A multi-start active-set optimization algorithm with six initial estimates ensures reliable and efficient localization.

CONCLUSIONS

The simulation suggests that the proposed design can achieve sufficient localization accuracy for pedicle screw navigation. These findings will guide the fabrication of a novel ultrasound-emitting drill guide for further evaluation and physical testing.

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

PURPOSE

The objective of this meta-analysis is to compare available computer-assisted navigation platforms by key performance metrics including pedicle screw placement accuracy, operative time, neurological complications, and blood loss.

METHODS

A systematic review was conducted using major databases for articles comparing pedicle screw accuracy of computer-assisted navigation to conventional (freehand or fluoroscopy) controls via post-operative computed tomography. Outcome data were extracted and pooled by random-effects model for analysis.

RESULTS

All navigation platforms demonstrated significant reduction in risk of breach, with Stryker demonstrating the highest accuracy compared to controls (OR 0.16 95% CI 0.06 to 0.41, P < 0.00001, I2 = 0%) followed by Medtronic. There were no significant differences in accuracy or most surgical outcome measures between platforms; however, BrainLab demonstrated significantly faster operative time compared to Medtronic by 30 min (95% CI - 63.27 to - 2.47, P = 0.03, I2 = 74%). Together, there was significantly lower risk of major breach in the navigation group compared to controls (OR 0.42, 95% CI 0.27-0.63, P < 0.0001, I2 = 56%).

CONCLUSIONS

When comparing between platforms, Stryker demonstrated the highest accuracy, and Brainlab the shortest operative time, both followed by Medtronic. No significant difference was found between platforms regarding neurologic complications or blood loss. Overall, our results demonstrated a 60% reduction in risk of major breach utilizing computer-assisted navigation, coinciding with previous studies, and supporting its validity. This study is the first to directly compare available navigation platforms offering insight for further investigation and aiding in the institutional procurement of platforms. LEVEL 3 EVIDENCE: Meta-analysis of Level 3 studies.

Supraspinous ligament arc tangent guided freehand thoracic pedicle screw insertion technique: high parallelism between screws and upper endplate

Research objective

To propose a technique for placing pedicle screws in the thoracic spine using the Supraspinous ligament Arc Tangent (SLAT) as a guide to increase the safety and stability of screw placement.

Content and methods

A retrospective analysis of postoperative anteroposterior and lateral x-ray images was performed for 118 patients with thoracic spine diseases who received conventional freehand technique from January 2016 to May 2020 and SLAT-guided technique since June 2020 to present. The diagnoses included thoracic spinal stenosis, deformity, fractures, infections, and tumors. The angle between the screw and the upper endplate was categorized as grade 1 (0°-5°), grade 2 (5°-10°), and grade 3 (>10°). Three surgeons with more than 10 years of experience in spinal surgery measured the angle between the screw and the upper endplate in the lateral view. Chi-square test was used for statistical analysis, and p < 0.05 was considered statistically significant.

Results

A total of 1315 pedicle screws were placed from T1 to T12 in all patients. In the conventional freehand technique group, 549 screws were grade 1, 35 screws were grade 2, and 23 screws were grade 3. In the SLAT-guided freehand technique group, 685 screws were grade 1, 15 screws were grade 2, and 8 screws were grade 3. The data of each group was p < 0.05 by Chi-squared test, which was statistically significant, indicating that the SLAT-guided freehand technique resulted in a higher rate of parallelism between the screws and the upper endplate. All patients underwent intraoperative neurophysiological monitoring, immediate postoperative neurological examination, postoperative x-ray examination, and assess the eventual recovery. The screws were safe and stable, and no complications related to pedicle screw placement were found.

Conclusion

The SLAT-guided freehand technique for placing pedicle screws in the thoracic spine can achieve a higher rate of screw-upper endplate parallelism, making screw placement safer and more accurate. Our method provides a convenient and reliable technique for most spinal surgeons, allowing for increased accuracy and safety with less fluoroscopic guidance.

The Role of 3D Printing in Treatment Planning of Spine and Sacral Tumors

Three-dimensional (3D) printing technology has proven to have many advantages in spine and sacrum surgery. 3D printing allows the manufacturing of life-size patient-specific anatomic and pathologic models to improve preoperative understanding of patient anatomy and pathology. Additionally, virtual surgical planning using medical computer-aided design software has enabled surgeons to create patient-specific surgical plans and simulate procedures in a virtual environment. This has resulted in reduced operative times, decreased complications, and improved patient outcomes. Combined with new surgical techniques, 3D-printed custom medical devices and instruments using titanium and biocompatible resins and polyamides have allowed innovative reconstructions.

Spine surgery in a state-of-the-art hybrid operating room: an experience of 1745 implanted pedicle screws in the thoracolumbar spine

Hybrid-operating rooms (hybrid-OR) combine high-resolution 2D images and 3D-scans with the possibility of 3D-navigation and allow minimal invasive pedicle screw placement even in the upper thoracic spine. The disadvantage of high cost and increased radiation needs to be compensated with high accuracy and safety. The hybrid operating room consists of a floor-based flat-panel robotic C-arm with 3D-scan capability (Artis Zeego, Siemens; Germany) combined with navigation (BrainLAB Curve, BrainLAB; Germany). Through a minimally invasive incision, a Jamshidi needle was advanced through the pedicle and a K-wire was placed. If 2D image quality did not allow safe placement 3D-navigation was used to place the K-wire. Position was controlled through a 3D-Scan and corrected if necessary before screw placement. Postoperative CTs evaluated screw perforation grade with grade I when completely within the pedicle, II < 2 mm, III 2-4 mm, and IV > 4 mm outside the pedicle. Overall, 354 screws were placed in T1-T6, 746 in the lower thoracic spine T7-T12 and 645 in the L1-L5. Navigation was mainly used in upper thoracic spine cases (31 of 57). In 63 out of 326 cases K-wire was corrected after the 3D-Scan. Overall, 99.1% of the screws showed perforation less than 2 mm. Mean radiation was 13.3 ± 11.7 mSv and significantly higher in the upper thoracic spine and in navigated procedures. Despite higher costs and radiation, the hybrid-OR allows highest accuracy and therefore patient safety in minimal invasive pedicle screw placement in the thoracic and lumbar spine.

Implications of navigation in thoracolumbar pedicle screw placement on screw accuracy and screw diameter/pedicle width ratio

Introduction

There is ample evidence that higher accuracy can be achieved in thoracolumbar pedicle screw placement by using spinal navigation. Still, to date, the evidence regarding the influence of the use of navigation on the screw diameter to pedicle width ratio remains limited.

Research question

The aim of this study was to investigate the implications of navigation in thoracolumbar pedicle screw placement not only on screw accuracy, but on the screw diameter to pedicle width ratio as well.

Material and methods

In this single-center single-surgeon study, 45 Patients undergoing navigated thoracolumbar pedicle screw placement were prospectively included. The results were compared with a matched comparison group of patients in which screw placement was performed under fluoroscopic guidance. The screw accuracy and the screw diameter to pedicle width ratio of every screw were compared between the groups.

Results

Screw accuracy was significantly higher in the navigation group compared to the fluoroscopic guidance group, alongside with a significant increase of the screw diameter to pedicle width ratio by approximately 10%. In addition, both the intraoperative radiation dose and the operating time tended to be lower in the study group.

Conclusion

This study was able to show that navigated thoracolumbar pedicle screw placement not only increases the accuracy of screw placement but also facilitates the selection of the adequate screw sizes, which according to the literature has positive effects on fixation strength. Meanwhile, the use of navigation did not negatively affect the time needed for surgery or the patient's intraoperative exposure to radiation.

Let's think beyond the pedicle: A biomechanical study of a new conceptual extra pedicular screw and hook construct

Background

Transpedicular screws have proven the test of time, yet they are not devoid of complications. Many newer techniques such as 2 D and 3D fluoroscopy,O arm Navigation assisted surgery, robotic assisted surgery have come into existence to the increase precision in pedicle screw insertion. But, complications do occur in their presence. We propose an Extra pedicular screw and hook system (EPSH) system with similar biomechanical property, better safety profile and short learning curve compared to traditional pedicle screw.

Purpose

To Compare the pull out strength of Traditional Pedicle screw Vs Extra pedicular screw and hook system(EPSH).

Methods

Biomechanical testing was conducted according ASTM F543 guidelines to compare the pull-out strength of EPSH based construct and traditional pedicle screw construct. Six saw bone samples in each group considered. Screw of 5.5 mm diameter and length of 35 mm was used in both the groups. Pull out strength assessed by giving 5 mm/min axial load. The axial load Vs displacement of the screw were recorded and plotted. The maximum load required for screw failure is noted in both the group. Statistical analysis was done.

Results

The mean peak load of pedicle screw group was found to be 1670.9 ± 393.2 N with mean displacement at peak load was found to be 13.44 ± 1.7 mm and in EPSH group it was 1416.4 ± 341.4 N and 15.78 ± 3.9 mm respectively. A paired t-test showed no statistical difference(p < 0.05) between 2 groups.

Conclusion

EPSH has shown to have almost similar biomechanical property as that pedicle screw construct. With Addition of the hook, it provides an extra rotational stability as well. Being an extra-pedicular screw it has high safety profile and needs less expertise for insertion.

Detection of Common Anatomical Landmarks and Vertical Trajectories for Freehand Pedicle Screw Placement

OBJECTIVE

It is clinically important for pedicle screws to be placed quickly and accurately. Misplacement of pedicle screws results in various complications. However, the incidence of complications varies greatly due to the different professional titles of physicians and surgical experience. Therefore, physicians must minimize pedicle screw dislocation. This study aims to compare the three nail placement methods in this study, and explore which method is the best for determining the anatomical landmarks and vertical trajectories.

METHODS

This study involved 70 patients with moderate idiopathic scoliosis who had undergone deformity correction surgery between 2018 and 2021. Two spine surgeons used three techniques (preoperative computed tomography scan [CTS], visual inspection-X-freehand [XFH], and intraoperative detection [ID] of anatomical landmarks) to locate pedicle screws. The techniques used include visual inspection for 287 screws in 21 patients, preoperative planning for 346 screws in 26 patients, and intraoperative probing for 309 screws in 23 patients. Observers assessed screw conditions based on intraoperative CT scans (Grade A, B, C, D).

RESULTS

There were no significant differences between the three groups in terms of age, sex, and degree of deformity. We found that 68.64% of screws in the XFH group, 67.63% in the CTS group, and 77.99% in the ID group were placed within the pedicle margins (grade A). On the other hand, 6.27% of screws in the XFH group, 4.33% in the CTS group, and 6.15% in the ID group were considered misplaced (grades C and D). The results show that the total amount of upper thoracic pedicle screws was fewer, meanwhile their placement accuracy was lower. The three methods used in this study had similar accuracy in intermediate physicians (P > 0.05). Compared with intermediate physicians, the placement accuracy of three techniques in senior physicians was higher. The intraoperative detection group was better than the other two groups in the good rate and accuracy of nail placement (P < 0.05).

CONCLUSION

Intraoperative common anatomical landmarks and vertical trajectories were beneficial to patients with moderate idiopathic scoliosis undergoing surgery. It is an optimal method for clinical application.

Safety and Accuracy of Freehand Pedicle Screw Placement and the Role of Intraoperative O-Arm: A Single-Institution Experience

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The aim was to investigate the accuracy of pedicle screw placement by freehand technique and to compare revision surgery rates among three different imaging verification pathways.

SUMMARY OF BACKGROUND DATA

Studies comparing different imaging modalities in freehand screw placement surgery are limited.

MATERIALS AND METHODS

A single-institution retrospective chart review identified adult patients who underwent freehand pedicle screw placement in the thoracic, lumbar or sacral levels. Patients were stratified into three cohorts based on the intraoperative imaging modality used to assess the accuracy of screw position: intraoperative X-rays (cohort 1); intraoperative O-arm (cohort 2); or intraoperative computed tomography (CT)-scan (cohort 3). Postoperative CT scans were performed on all patients in cohorts 1 and 2. Postoperative CT scan was not required in cohort 3. Screw accuracy was assessed using the Gertzbein-Robbins grading system.

RESULTS

A total of 9179 pedicle screws were placed in the thoracic or lumbosacral spine in 1311 patients. 210 (2.3%) screws were identified as Gertzbein-Robbins grades C-E on intraoperative/postoperative CT scan, 137 thoracic screws, and 73 lumbar screws ( P <0.001). Four hundred and nine patients underwent placement of 2754 screws followed by intraoperative X-ray (cohort 1); 793 patients underwent placement of 5587 screws followed by intraoperative O-arm (cohort 2); and 109 patients underwent placement of 838 screws followed by intraoperative CT scan (cohort 3). Postoperative CT scans identified 65 (2.4%) and 127 (2.3%) malpositioned screws in cohorts 1 and 2, respectively. Eleven screws (0.12%) were significantly malpositioned and required a second operation for screw revision. Nine patients (0.69%) required revision operations: eight of these patients were from cohort 1 and one patient was from cohort 2.

CONCLUSION

When compared to intraoperative X-ray, intraoperative O-arm verification decreased the revision surgery rate for malpositioned screws from 0.37% to 0.02%. In addition, our analysis suggests that the use of intraoperative O-arm can obviate the need for postoperative CT scans.

Paediatric Spinal Deformity Surgery: Complications and Their Management

Surgical correction of paediatric spinal deformity is associated with risks, adverse events, and complications that must be preoperatively discussed with patients and their families to inform treatment decisions, expectations, and long-term outcomes. The incidence of complications varies in relation to the underlying aetiology of spinal deformity and surgical procedure. Intraoperative complications include bleeding, neurological injury, and those related to positioning. Postoperative complications include persistent pain, surgical site infection, venous thromboembolism, pulmonary complications, superior mesenteric artery syndrome, and also pseudarthrosis and implant failure, proximal junctional kyphosis, crankshaft phenomenon, and adding-on deformity, which may necessitate revision surgery. Interventions included in enhanced recovery after surgery protocols may reduce the incidence of complications. Complications must be diagnosed, investigated and managed expeditiously to prevent further deterioration and to ensure optimal outcomes. This review summarises the complications associated with paediatric spinal deformity surgery and their management.

Size selection and placement of pedicle screws using robot-assisted versus fluoroscopy-guided techniques for thoracolumbar fractures: possible implications for the screw loosening rate

Background

There has been increased development of robotic technologies for the accuracy of percutaneous pedicle screw placement. However, it remains unclear whether the robot really optimize the selection of screw sizes and enhance screw stability. The purpose of this study is to compare the sizes (diameter and length), placement accuracy and the loosening rate of pedicle screws using robotic-assisted versus conventional fluoroscopy approaches for thoracolumbar fractures.

Methods

A retrospective cohort study was conducted to evaluate 70 consecutive patients [34 cases of robot-assisted percutaneous pedicle screw fixation (RAF) and 36 of conventional fluoroscopy-guided percutaneous pedicle screw fixation (FGF)]. Demographics, clinical characteristics, and radiological features were recorded. Pedicle screw length, diameter, and pedicle screw placement accuracy were assessed. The patients’ sagittal kyphosis Cobb angles (KCA), anterior vertebral height ratios (VHA), and screw loosening rate were evaluated by radiographic data 1 year after surgery.

Results

There was no significant difference in the mean computed tomography (CT) Hounsfield unit (HU) values, operation duration, or length of hospital stay between the groups. Compared with the FGF group, the RAF group had a lower fluoroscopy frequency [14 (12–18) vs. 21 (16–25), P < 0.001] and a higher “grade A + B” pedicle screw placement rate (96.5% vs. 89.4%, P < 0.05). The mean screw diameter was 6.04 ± 0.55 mm in the RAF group and 5.78 ± 0.50 mm in the FGF group (P < 0.001). The mean screw length was 50.45 ± 4.37 mm in the RAF group and 48.63 ± 3.86 mm in the FGF group (P < 0.001). The correction loss of the KCA and VHR of the RAF group was less than that of the FGT group at the 1-year follow-up [(3.8 ± 1.8° vs. 4.9 ± 4.2°) and (5.5 ± 4.9% vs. 6.4 ± 5.7%)], and screw loosening occurred in 2 out of 34 patients (5.9%) in the RAF group, and 6 out of 36 patients (16.7%) in the FGF group, but there were no significant differences (P > 0.05).

Conclusion

Compared with the fluoroscopy-guided technique, robotic-assisted spine surgery decreased radiation exposure and optimizes screw trajectories and dimensions intraoperatively. Although not statistically significant, the loosening rate of the RAF group was lower that of than the FGT group.

Intraoperative CT-guided navigation versus fluoroscopy for percutaneous pedicle screw placement in 192 patients: a comparative analysis

BACKGROUND

Percutaneous pedicle screw (PPS) placement is a key step in several minimally invasive spinal surgery (MISS) procedures. Traditional technique for PPS makes use of C-arm fluoroscopy assistance (FA). More recently, newer intraoperative imaging techniques have been developed for PPS, including CT-guided navigation (CTNav). The aim of this study was to compare FA and CTNav techniques for PPS with regard to accuracy, complications, and radiation dosage.

MATERIALS AND METHODS

A total of 192 patients with degenerative lumbar spondylolisthesis and canal stenosis who underwent MISS posterior fusion ± interbody fusion through transforaminal approach (TLIF) were retrospectively reviewed. Pedicle screws were placed percutaneously using either standard C-arm fluoroscopy guidance (FA group) or CT navigation (CTNav group). Intraoperative effective dose (ED, mSv) was measured. Screw placement accuracy was assessed postoperatively on a CT scan using Gertzbein and Robbins classification (grades A-E). Oswestry disability index (ODI) and visual analog scale (VAS) scores were compared in both groups before and after surgery.

RESULTS

A total of 101 and 91 procedures were performed with FA (FA group) and CTNav approach (CTNav group), respectively. Median age was 61 years in both groups, and the most commonly treated level was L4-L5. Median ED received from patients was 1.504 mSv (0.494-4.406) in FA technique and 21.130 mSv (10.840-30.390) in CTNav approach (p < 0.001). Percentage of grade A and B screws was significantly higher for the CTNav group (96.4% versus 92%, p < 0.001), whereas there were 16 grade E screws in the FA group and 0 grade E screws in the CTNav group (p < 0.001). A total of seven and five complications were reported in the FA and CTNav group, respectively (p = 0.771).

CONCLUSIONS

CTNav technique increases accuracy of pedicle screw placement compared with FA technique without affecting operative time. Nevertheless, no significant difference was noted in terms of reoperation rate due to screw malpositioning between CTNav and FA techniques. Radiation exposure of patients was significantly higher with CTNav technique.

LEVEL OF EVIDENCE

Level 3.

CT-Navigated Spinal Instrumentations-Three-Dimensional Evaluation of Screw Placement Accuracy in Relation to a Screw Trajectory Plan

Background and Objectives: In the literature, spinal navigation and robot-assisted surgery improved screw placement accuracy, but the majority of studies only qualitatively report on screw positioning within the vertebra. We sought to evaluate screw placement accuracy in relation to a preoperative trajectory plan by three-dimensional quantification to elucidate technical benefits of navigation for lumbar pedicle screws. Materials and Methods: In 27 CT-navigated instrumentations for degenerative disease, a dedicated intraoperative 3D-trajectory plan was created for all screws. Final screw positions were defined on postoperative CT. Trajectory plans and final screw positions were co-registered and quantitatively compared computing minimal absolute differences (MAD) of screw head and tip points (mm) and screw axis (degree) in 3D-space, respectively. Differences were evaluated with consideration of the navigation target registration error. Clinical acceptability of screws was evaluated using the Gertzbein−Robbins (GR) classification. Results: Data included 140 screws covering levels L1-S1. While screw placement was clinically acceptable in all cases (GR grade A and B in 112 (80%) and 28 (20%) cases, respectively), implanted screws showed considerable deviation compared to the trajectory plan: Mean axis deviation was 6.3° ± 3.6°, screw head and tip points showed mean MAD of 5.2 ± 2.4 mm and 5.5 ± 2.7 mm, respectively. Deviations significantly exceeded the mean navigation registration error of 0.87 ± 0.22 mm (p < 0.001). Conclusions: Screw placement was clinically acceptable in all screws after navigated placement but nevertheless, considerable deviation in implanted screws was noted compared to the initial trajectory plan. Our data provides a 3D-quantitative benchmark for screw accuracy achievable by CT-navigation in routine spine surgery and suggests a framework for objective comparison of screw outcome after navigated or robot-assisted procedures. Factors contributing to screw deviations should be considered to assure optimal surgical results when applying navigation for spinal instrumentation.

Assessing the accuracy of a new 3D2D registration algorithm based on a non-invasive skin marker model for navigated spine surgery

Purpose

We assessed the accuracy of a new 3D2D registration algorithm to be used for navigated spine surgery and explored anatomical and radiologic parameters affecting the registration accuracy. Compared to existing 3D2D registration algorithms, the algorithm does not need bone-mounted or table-mounted instruments for registration. Neither does the intraoperative imaging device have to be tracked or calibrated.

Methods

The rigid registration algorithm required imaging data (a pre-existing CT scan (3D) and two angulated fluoroscopic images (2D)) to register positions of vertebrae in 3D and is based on non-invasive skin markers. The algorithm registered five adjacent vertebrae and was tested in the thoracic and lumbar spine from three human cadaveric specimens. The registration accuracy was calculated for each registered vertebra and measured with the target registration error (TRE) in millimeters. We used multivariable analysis to identify parameters independently affecting the algorithm’s accuracy such as the angulation between the two fluoroscopic images (between 40° and 90°), the detector-skin distance, the number of skin markers applied, and waist circumference.

Results

The algorithm registered 780 vertebrae with a median TRE of 0.51 mm [interquartile range 0.32–0.73 mm] and a maximum TRE of 2.06 mm. The TRE was most affected by the angulation between the two fluoroscopic images obtained (p < 0.001): larger angulations resulted in higher accuracy. The algorithm was more accurate in thoracic vertebrae (p = 0.004) and in the specimen with the smallest waist circumference (p = 0.003). The algorithm registered all five adjacent vertebrae with similar accuracy.

Conclusion

We studied the accuracy of a new 3D2D registration algorithm based on non-invasive skin markers. The algorithm registered five adjacent vertebrae with similar accuracy in the thoracic and lumbar spine and showed a maximum target registration error of approximately 2 mm. To further evaluate its potential for navigated spine surgery, the algorithm may now be integrated into a complete navigation system.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11548-022-02733-w.

First Clinical Experience with a Novel 3D C-Arm-Based System for Navigated Percutaneous Thoracolumbar Pedicle Screw Placement

Background and Objectives: Navigated pedicle screw placement is becoming increasingly popular, as it has been shown to reduce the rate of screw misplacement. We present our intraoperative workflow and initial experience in terms of safety, efficiency, and clinical feasibility with a novel system for a 3D C-arm cone beam computed-tomography-based navigation of thoracolumbar pedicle screws. Materials and Methods: The first 20 consecutive cases of C-arm cone beam computed-tomography-based percutaneous pedicle screw placement using a novel navigation system were included in this study. Procedural data including screw placement time and patient radiation dose were prospectively collected. Final pedicle screw accuracy was assessed using the Gertzbein–Robbins grading system. Results: In total, 156 screws were placed. The screw accuracy was 94.9%. All the pedicle breaches occurred on the lateral pedicle wall, and none caused clinical complications. On average, a time of 2:42 min was required to place a screw. The mean intraoperative patient radiation exposure was 7.46 mSv. Conclusions: In summary, the investigated combination of C-arm CBCT-based navigation proved to be easy to implement and highly reliable. It facilitates the accurate and efficient percutaneous placement of pedicle screws in the thoracolumbar spine. The careful use of intraoperative imaging maintains the intraoperative radiation exposure to the patient at a moderate level.

Robot-assisted and augmented reality-assisted spinal instrumentation: a systematic review and meta-analysis of screw accuracy and outcomes over the last decade

OBJECTIVE

The use of technology-enhanced methods in spine surgery has increased immensely over the past decade. Here, the authors present the largest systematic review and meta-analysis to date that specifically addresses patient-centered outcomes, including the risk of inaccurate screw placement and perioperative outcomes in spinal surgeries using robotic instrumentation and/or augmented reality surgical navigation (ARSN).

METHODS

A systematic review of the literature in the PubMed, EMBASE, Web of Science, and Cochrane Library databases spanning the last decade (January 2011-November 2021) was performed to present all clinical studies comparing robot-assisted instrumentation and ARSN with conventional instrumentation techniques in lumbar spine surgery. The authors compared these two technologies as they relate to screw accuracy, estimated blood loss (EBL), intraoperative time, length of stay (LOS), perioperative complications, radiation dose and time, and the rate of reoperation.

RESULTS

A total of 64 studies were analyzed that included 11,113 patients receiving 20,547 screws. Robot-assisted instrumentation was associated with less risk of inaccurate screw placement (p < 0.0001) regardless of control arm approach (freehand, fluoroscopy guided, or navigation guided), fewer reoperations (p < 0.0001), fewer perioperative complications (p < 0.0001), lower EBL (p = 0.0005), decreased LOS (p < 0.0001), and increased intraoperative time (p = 0.0003). ARSN was associated with decreased radiation exposure compared with robotic instrumentation (p = 0.0091) and fluoroscopy-guided (p < 0.0001) techniques.

CONCLUSIONS

Altogether, the pooled data suggest that technology-enhanced thoracolumbar instrumentation is advantageous for both patients and surgeons. As the technology progresses and indications expand, it remains essential to continue investigations of both robotic instrumentation and ARSN to validate meaningful benefit over conventional instrumentation techniques in spine surgery.

Comparison of three imaging and navigation systems regarding accuracy of pedicle screw placement in a sawbone model

3D-navigated pedicle screw placement is increasingly performed as the accuracy has been shown to be considerably higher compared to fluoroscopy-guidance. While different imaging and navigation devices can be used, there are few studies comparing these under similar conditions. Thus, the objective of this study was to compare the accuracy of two combinations most used in the literature for spinal navigation and a recently approved combination of imaging device and navigation system. With each combination of imaging system and navigation interface, 160 navigated screws were placed percutaneously in spine levels T11-S1 in ten artificial spine models. 470 screws were included in the final evaluation. Two blinded observers classified screw placement according to the Gertzbein Robbins grading system. Grades A and B were considered acceptable and Grades C-E unacceptable. Weighted kappa was used to calculate reliability between the observers. Mean accuracy was 94.9% (149/157) for iCT/Curve, 97.5% (154/158) for C-arm CBCT/Pulse and 89.0% for CBCT/StealthStation (138/155). The differences between the different combinations were not statistically significant except for the comparison of C-arm CBCT/Pulse and CBCT/StealthStation (p = 0.003). Relevant perforations of the medial pedicle wall were only seen in the CBCT group. Weighted interrater reliability was found to be 0.896 for iCT, 0.424 for C-arm CBCT and 0.709 for CBCT. Under quasi-identical conditions, higher screw accuracy was achieved with the combinations iCT/Curve and C-arm CBCT/Pulse compared with CBCT/StealthStation. However, the exact reasons for the difference in accuracy remain unclear. Weighted interrater reliability for Gertzbein Robbins grading was moderate for C-arm CBCT, substantial for CBCT and almost perfect for iCT.

Accuracy of pedicle screw placement using neuronavigation based on intraoperative 3D rotational fluoroscopy in the thoracic and lumbar spine

INTRODUCTION

In spinal surgery, precise instrumentation is essential. This study aims to evaluate the accuracy of navigated, O-arm-controlled screw positioning in thoracic and lumbar spine instabilities.

MATERIALS AND METHODS

Posterior instrumentation procedures between 2010 and 2015 were retrospectively analyzed. Pedicle screws were placed using 3D rotational fluoroscopy and neuronavigation. Accuracy of screw placement was assessed using a 6-grade scoring system. In addition, screw length was analyzed in relation to the vertebral body diameter. Intra- and postoperative revision rates were recorded.

RESULTS

Thoracic and lumbar spine surgery was performed in 285 patients. Of 1704 pedicle screws, 1621 (95.1%) showed excellent positioning in 3D rotational fluoroscopy imaging. The lateral rim of either pedicle or vertebral body was protruded in 25 (1.5%) and 28 screws (1.6%), while the midline of the vertebral body was crossed in 8 screws (0.5%). Furthermore, 11 screws each (0.6%) fulfilled the criteria of full lateral and medial displacement. The median relative screw length was 92.6%. Intraoperative revision resulted in excellent positioning in 58 of 71 screws. Follow-up surgery due to missed primary malposition had to be performed for two screws in the same patient. Postsurgical symptom relief was reported in 82.1% of patients, whereas neurological deterioration occurred in 8.9% of cases with neurological follow-up.

CONCLUSIONS

Combination of neuronavigation and 3D rotational fluoroscopy control ensures excellent accuracy in pedicle screw positioning. As misplaced screws can be detected reliably and revised intraoperatively, repeated surgery for screw malposition is rarely required.

Beyond Placement of Pedicle Screws - New Applications for Robotics in Spine Surgery: A Multi-Surgeon, Single-Institution Experience

Interest in robotic-assisted spine surgery has grown as surgeon comfort and technology has evolved to maximize benefits of time saving and precision. However, the Food and Drug Administration (FDA) has currently only approved robotics to assist in determining the ideal trajectory for pedicle screw placement after extensive research supporting its efficacy and efficiency. To be considered a durable and effective option, robotics need to expand beyond the indication of just placing pedicle screws. This article aims to illustrate a multi-surgeon, single-institution experience with unique applications of robotic technologies in spine surgery. We will explore accessing Kambin's Triangle in percutaneous transforaminal interbody fusion (percLIF), iliac fixation in metastatic cancer, and sacroiliac (SI) fusions. Each of these topics will be covered in depth with associated background information and subsequent discussion. We show that with proper understanding of its limitations, robots can help surgeons perform difficult surgeries in a safe manner.

Intraoperative Transcranial Electrical Motor Evoked Potential (TceMEP) as a Therapeutic Tool in Spine Surgery: A Case Series Report

We report two cases of unilateral loss of TceMEP secondary to spinal instrumentation errors and the subsequent recovery of TceMEP responses following prompt intervention. During the period of TceMEP loss, there were no concomitant SSEP changes beyond the threshold criteria. Postoperative physical examination revealed normal strength and motion in the affected extremities in both patients. These cases illustrate that in addition to being a reliable intraoperative diagnostic tool, TceMEP monitoring displays therapeutic usefulness in appraising corrective actions to the existential risk of neurological injuries.

Accuracy of Pedicle Screw Placement Methods in Pediatrics and Adolescents Spinal Surgery: A Systematic Review and Meta-Analysis

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVE

Various methods of pedicle screw (PS) placement in spinal fusion surgery existed, which can be grouped into conventional freehand (FH), modified freehand (MF), and image-guided methods (including fluoroscopy-based navigation (FL), computed tomography-based navigation (CT-nav), robot-assisted (RA), and ultrasound-guided (UG)). However, the literature showed mixed findings regarding their accuracy and complications. This review aimed to discover which method of PS placement has the highest accuracy and lowest complication rate in pediatric and adolescent spinal fusion surgery.

METHODS

A comprehensive search in MEDLINE (PubMed), EMBASE (OVID), CENTRAL, and Web of Science was conducted until May 2020 by 2 independent reviewers, followed by bias assessment with ROB 2 and ROBINS-I tools and quantification with meta-analysis. Overall evidence quality was determined with GRADE tool.

RESULTS

Four RCTs and 2 quasi-RCTs/CCTs comprising 3,830 PS placed in 291 patients (4-22 years old) were analyzed. The lowest accuracy was found in FH (78.35%) while the highest accuracy was found in MF (95.86%). MF was more accurate than FH (OR 3.34 (95% CI, 2.33-4.79), P < .00 001, I2 = 0%). Three-dimensional printed drill template (as part of MF) was more accurate than FH (OR 3.10 (95% CI, 1.98-4.86), P < .00 001, I2 = 14%). Overall, complications occurred in 5.84% of the patients with 0.34% revision rate. Complication events in MF was lower compared to FH (OR 0.47 (95% CI, 0.10-2.15), P = .33, I2 = 0%).

CONCLUSIONS

Meta-analysis shows that MF is more accurate than FH in pediatric and adolescent requiring PS placement for spinal fusion surgery.