Technique For Pedicle Screw Placement Research Articles

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.

Technique, Safety, and Accuracy Assessment of Percutaneous Pedicle Screw Placement Utilizing Computer-Assisted Navigation in Lateral Decubitus Single-Position Surgery.

Percutaneous pedicle screw (PPS) placement has become a pivotal technique in spinal surgery, increasing surgical efficiency and limiting the invasiveness of surgical procedures. The aim of this study was to analyze the accuracy of computer-assisted PPS placement with a standardized technique in the lateral decubitus position. A retrospective review of prospectively collected data was performed on 44 consecutive patients treated between 2021 and 2023 with lateral decubitus single-position surgery. PPS placement was assessed by computed tomography scans, and breaches were graded based on the magnitude and direction of the breach. Facet joint violations were assessed. Variables collected included patient demographics, indication, intraoperative complications, operative time, fluoroscopy time, estimated blood loss, and length of stay. Forty-four patients, with 220 PPSs were identified. About 79.5% of all patients underwent anterior lumbar interbody fusion only, 13.6% underwent lateral lumbar interbody fusion only, and 6.8% received a combination of both anterior lumbar interbody fusion and lateral lumbar interbody fusion. Eleven screw breaches (5%) were identified: 10 were Grade II breaches (<2 mm), and 1 was a Grade IV breach (>4 mm). All breaches were lateral. About 63.6% involved down-side screws indicating a trend toward the laterality of breaches for down-side pedicles. When analyzing breaches by level, 1.2% of screws at L5, 13% at L4, and 11.1% at L3 demonstrated Grade II breaches. No facet joint violations were noted. PPS placement utilizing computer-assisted navigation in lateral decubitus single-position surgery is both safe and accurate. An overall breach rate of 5% was found; considering a safe zone of 2 mm, only 1 screw (0.5%) demonstrated a relevant breach. PPS placement is both safe and accurate. Breaches are rare, and when breaches do occur, they are lateral.

Comparative evaluation of postoperative outcomes and expenditure between robotic and conventional single-level lumbar fusion surgery: a comprehensive analysis of nationwide inpatient sample data

IntroductionIn this study, we investigate the evolution of lumbar fusion surgery with robotic assistance, specifically focusing on the impact of robotic technology on pedicle screw placement and fixation. Utilizing data from the Nationwide Inpatient Sample (NIS) covering 2016 to 2019, we conduct a comprehensive analysis of postoperative outcomes and costs for single-level lumbar fusion surgery. Traditionally, freehand techniques for pedicle screw placement posed risks, leading to the development of robotic-assisted techniques with advantages such as reduced misplacement, increased precision, smaller incisions, and decreased surgeon fatigue. However, conflicting study results regarding the efficacy of robotic assistance in comparison to conventional techniques have prompted the need for a thorough evaluation. With a dataset of 461,965 patients, our aim is to provide insights into the impact of robotic assistance on patient care and healthcare resource utilization. Our primary goal is to contribute to the ongoing discourse on the efficacy of robotic technology in lumbar fusion procedures, offering meaningful insights for optimizing patient-centered care and healthcare resource allocation.MethodsThis study employed data from the Nationwide Inpatient Sample (NIS) spanning the years 2016 to 2019 from USA, 461,965 patients underwent one-level lumbar fusion surgery, with 5770 of them having the surgery with the assistance of robotic technology. The study focused primarily on one-level lumbar fusion surgery and excluded non-elective cases and those with prior surgeries. The analysis encompassed the identification of comorbidities, surgical etiologies, and complications using specific ICD-10 codes. Throughout the study, a constant comparison was made between robotic and non-robotic lumbar fusion procedures. Various statistical methods were applied, with a p value threshold of < 0.05, to determine statistical significance.ResultsRobotic-assisted lumbar fusion surgeries demonstrated a significant increase from 2016 to 2019, comprising 1.25% of cases. Both groups exhibited similar patient demographics, with minor differences in payment methods, favoring Medicare in non-robotic surgery and more private payer usage in robotic surgery. A comparison of comorbid conditions revealed differences in the prevalence of hypertension, dyslipidemia, and sleep apnea diagnoses—In terms of hospitalization outcomes and costs, there was a slight shorter hospital stay of 3.06 days, compared to 3.13 days in non-robotic surgery, showcasing a statistically significant difference (p = 0.042). Robotic surgery has higher charges, with a mean charge of $154,673, whereas non-robotic surgery had a mean charge of $125,467 (p < 0.0001). Robotic surgery demonstrated lower rates of heart failure, acute coronary artery disease, pulmonary edema, venous thromboembolism, and traumatic spinal injury compared to non-robotic surgery, with statistically significant differences (p < 0.05). Conversely, robotic surgery demonstrated increased post-surgery anemia and blood transfusion requirements compared to non-robotic patients (p < 0.0001). Renal disease prevalence was similar before surgery, but acute kidney injury was slightly higher in the robotic group post-surgery (p = 0.038).ConclusionThis is the first big data study on this matter, our study showed that Robotic-assisted lumbar fusion surgery has fewer post-operative complications such as heart failure, acute coronary artery disease, pulmonary edema, venous thromboembolism, and traumatic spinal injury in comparison to conventional methods. Conversely, robotic surgery demonstrated increased post-surgery anemia, blood transfusion and acute kidney injury. Robotic surgery has higher charges compared to non-robotic surgery.

Surgical stabilization for degenerative lesions of the lumbar spine in patients with reduced bone mineral density: a systematic literature review

Objective. To analyze methods contributing to the improvement of clinical and radiological outcomes of surgical stabilization of the lumbar spine in conditions of reduced bone mineral density (BMD).Material and Methods. A search for publications presenting the results of clinical studies of surgical treatment of patients with degenerative lesions of the lumbar spine and reduced BMD was conducted in English and Russian in the MEDLINE and Russian Science Citation Index (RSCI) databases using key words “osteoporosis”, “osteopenia”, “spinal surgery”, “spinal fusion” and related terms in titles and abstracts with a search depth of 20 years. After applying the inclusion and exclusion criteria, 17 clinical studies were selected for analysis.Results. Among the large number of techniques and implant-associated factors affecting the success of surgical intervention for degenerative lesions of the lumbar spine and reduced BMD, high-quality clinical studies have proven the effectiveness of expandable screws, spinal fusion with cortical screw placement and cement augmentation with polymethyl methacrylate.Conclusion. The combination of techniques for cortical pedicle screw placement, cement augmentation and the use of expandable screws makes it possible to achieve results in surgical treatment of patients with degenerative lesions of the lumbar spine with reduced BMD comparable with those in patients with normal BMD. Of particular importance is the preoperative assessment of the regional state of bone tissue, which should be carried out using quantitative CT or MRI studies.

Comparative efficacy of robotic-assisted and freehand techniques for pedicle screw placement in spinal disorders: a meta-analysis and systematic review.

The efficacy and safety of robotic-assisted pedicle screw placement compared to traditional fluoroscopy-guided techniques are of great interest in the field of spinal surgery. This systematic review and meta-analysis aimed to compare the outcomes of these two methods in patients with spinal diseases. Following the PRISMA guidelines, we conducted a systematic search across PubMed, Embase, Web of Science, and Cochrane Library. We included randomized controlled trials comparing robotic-assisted and fluoroscopy-guided pedicle screw placement in patients with spinal diseases. Outcome measures included the accuracy of pedicle screw placement, postoperative complication rates, intraoperative radiation exposure time, and duration of surgery. Data were analyzed using Stata software. Our analysis included 12 studies. It revealed significantly higher accuracy in pedicle screw placement with robotic assistance (odds ratio [OR] = 2.83, 95% confidence interval [CI] = 2.20-3.64, P < 0.01). Postoperative complication rates, intraoperative radiation exposure time, and duration of surgery were similar between the two techniques (OR = 0.72, 95% CI = 0.31 to 1.68, P = 0.56 for complication rates; weighted mean difference [WMD] = -0.13, 95% CI = -0.93 to 0.68, P = 0.86 for radiation exposure time; WMD = 0.30, 95% CI = -0.06 to 0.66, P = 0.06 for duration of surgery). Robotic-assisted pedicle screw placement offers superior placement accuracy compared to fluoroscopy-guided techniques. Postoperative complication rates, intraoperative radiation exposure time, and duration of surgery were comparable for both methods. Future studies should explore the potential for fewer complications with the robotic-assisted approach as suggested by the lower point estimate.

Modified Tap-drilling Technique for Mid-cervical Pedicle Screw Placement: A Case Series of 473 Consecutive Screws.

Retrospective cohort study. To report our modified tap-drilling technique for mid-cervical pedicle screw placement and to evaluate its safety and accuracy. Cervical pedicle screw fixation, which provides a strong stabilization, has been a major concern due to the potential risks to neurovascular structures despite its increasing use. Several insertion techniques have been described so far to improve the cervical pedicle screw placement accuracy. This study retrospectively reviewed patients who underwent mid-cervical (C3-C6) pedicle screw fixation between September 2005 and September 2020. Laminectomy, laminoforaminotomy, or notch-referred anatomic landmark methods were used to adjust the entry point and the direction of the screws. After the cortical bone was removed at the entry point with a diamond burr, the cancellous bone was slowly drilled with a hand drill starting from 8 to 10 millimeters in length. Then, all of the bone walls were checked with a ball-tip probe to determine if there was any breach. The procedure was repeated several times. After completing the drilling, the screw was inserted without tapping. The breach rate of pedicle screws was analyzed on postoperative computed tomography scans. A total of 473 mid-cervical pedicle screws were placed in 122 consecutive patients. No navigation or computer-assisted system was used, and the first 2 authors inserted all of the screws. All patients completed the surgery, and no evident intraoperative complications occurred. Postoperative CT scans were obtained for 405 screws. Although deviation was observed for 131 pedicle screws, a critical deviation was observed for only 25 pedicle screws. Cervical pedicle screw insertion is a risky but applicable technique. Checking all of the bone walls with a ball-tip probe before gradually advancing the hand drill in small amounts, as presented in this article, may lead to the safe and effective placement of cervical pedicle screws.

Freehand Technique for Pedicle Screw Placement during Surgery for Adolescent Idiopathic Scoliosis Is Associated with Less Ionizing Radiation Compared to Intraoperative Navigation.

We aim to compare radiation exposure and implant-related complications of the freehand (FH) technique versus intraoperative image-guided navigation (IN) for pedicle screw placement in adolescent idiopathic scoliosis (AIS) and estimate associated lifetime attributable cancer risks. A retrospective analysis of prospectively collected data from 40 consecutive AIS patients treated with pedicle screw instrumentation using the FH technique was performed. The dose area product (DAP) and effective dose (ED) were calculated. Screw-related complications were analysed, and the age- and gender-specific lifetime attributable cancer risks were estimated. The results were compared to previously published data on IN used during surgery for AIS. There were no implant-related complications in our cohort. Implant density was 86.6%. The mean Cobb angle of the main curve was 75.2° (SD ± 17.7) preoperatively and 27.7° (SD ± 10.8) postoperatively. The mean ED of our cohort and published data for the FH technique was significantly lower compared to published data on the IN technique (p < 0.001). The risk for radiogenic cancer for our FH technique AIS cohort was 0.0014% for male patients and 0.0029% for female patients. Corresponding risks for IN were significantly higher (p < 0.001), ranging from 0.0071 to 0.124% and from 0.0144 to 0.253% for male and female patients, respectively. The routine use of intraoperative navigation in AIS surgery does not necessarily reduce implant-related complications but may increase radiation exposure to the patient.

The articular surface technique for lumbar pedicle screw placement: a 3D feasibility study.

Traditional pedicle screws (TPSs) and cortical based trajectory pedicle screws each apply stability with fusions of the lumbar spine and have shown good success. However, the technical considerations of each technique imply complications of loosening and failure that either technique is uniquely prone to having. The current study proposes a new pedicle screw technique through the articular surface of the vertebral superior facet. It is hypothesized that this path will allow utilization of a larger screw that rivals that of the TPS technique, while also maintaining the high-density bone encountered in the cortical based trajectory technique. Retrospective review of 50 consecutive trauma patients that underwent lumbar computed tomography (CT) scans at a Level 1 Trauma Center in the age range 18-45. These scans were uploaded to Brainlab software for ideal starting point and trajectory mapping of pedicle screws coursing through each superior facet and pedicle of vertebral levels L1-S1 without cortical breach. Satisfactory pedicle screw variables consisted of a medial angle <10 degrees, screw length at least 30 mm, screw width at least 5.0 mm, and starting point measurements such as distance to the inferior articular surface and distance to the lateral articular surface. A total of 600 virtual pedicle screws were placed, in which 525 were satisfactory and measured with the above variables. The pedicle widths were shown to significantly widen with lower-level vertebra in the lumbar spine. Approximately 72% of unsuccessful pedicle screws were placed in levels L1 and L2 allowing wider pedicle screws to be placed more further down the vertebral column. The articular surface technique (AST) for pedicle screw placement is a viable alternative in lumbar spinal fusions that offers decreased soft tissue dissection. However, the technique is likely better suited for lower lumbar fusions in L3 to S1.

A Novel Free-hand Technique of Pedicle Screw Placement in the Lumbar Spine: Accuracy Evaluation and Preliminary Clinical Results.

Pedicle screw implantation is the most common technique to achieve stability during spinal surgeries. Current methods for locating the entry point do not have a quantified criteria and highly rely on the surgeons' experience. Therefore, we aim to propose a quantified pedicle screw placement technique in the lumbar spine and to investigate its accuracy and safety in clinical practice. We conducted a retrospective study involving 110 patients who received spinal surgery in our hospital from August 2018 to August 2021. All patients included had herniation of a single lumbar disc and were consistently treated with posterior discectomy, inter-body fusion, and transpedicular internal fixation. For 54 patients in the observation group, the pedicle screws were placed with our technique, which is located at 4 mm below the superior edge of the transverse process in line with the lateral margin of the superior articular process. For 56 patients in the control group, pedicle screws were placed according to the traditional crista lambdoidalis method. Comparisons were made in terms of the operation time, blood loss, time for exposure, the accuracy of placement, and postoperative complications. Furthermore, we applied our method to 64 patients with indistinguishable crista lambdoidalis and evaluated the accuracy of screw placement and clinical outcomes according to the visual analogue scale (VAS) and the Japanese Orthopaedic Association (JOA) score. There was no significant difference in intraoperative bleeding, accuracy of placement, and postoperative complications between our technique and the traditional crista lambdoidalis method (P > 0.05). However, the exposure time before screw placement (12.8 ± 0.3 vs. 17.4 ± 0.3, P = 0.001) and the total surgery time (97.2 ± 1.9 vs 102.3 ± 0.9, P = 0.020) were significantly shortened with our method. Additionally, in cases with indistinguishable crista lambdoidalis, our technique showed satisfying accuracy, with 97.6% screws placed in appropriate trajectory on the first attempt and all screws eventually positioned in the safe zone according to the Gertzbein-Robbins grading. All patients experienced steady improvement after surgery. Placing pedicle screws at 4 mm below the superior edge of the transverse process in line with the lateral margin of the superior articular process is a viable pedicle screw placement method. With this method, we observed a higher success rate and shorter operation time. In addition, this method can be applied in cases with indistinguishable crista lambdoidalis, and have satisfied success rate and clinical outcome.

The Child's Age and the Size of the Curvature Do Not Affect the Accuracy of Screw Placement with the Free-Hand Technique in Spinal Deformities in Children and Adolescents.

The current method of treatment of spinal deformities would be almost impossible without pedicle screws (PS) placement. There are only a few studies evaluating the safety of PS placement and possible complications in children during growth. The present study was carried out to evaluate the safety and accuracy of PS placement in children with spinal deformities at any age using postoperative computed tomography (CT) scans. 318 patients (34 males and 284 females) who underwent 6358 PS fixations for pediatric spinal deformities were enrolled in this multi-center study. The patients were divided into three age groups: less than 10 years old, 11-13 years old, and 14-18 years old. These patients underwent postoperative CT scans and were analyzed for pedicle screw malposition (anterior, superior, inferior, medial, and lateral breaches). The breach rate was 5.92% for all pedicles. There were 1.47% lateral and 3.12% medial breaches for all pedicles with tapping canals, and 2.66% lateral and 3.84% medial breaches for all pedicles without a tapping canal for the screw. Of the 6358 screws placed in the thoracic, lumbar, and sacral spine, 98% of the screws were accurately placed (grade 0, 1, and juxta pedicular). A total of 56 screws (0.88%) breached more than 4 mm (grade 3), and 17 (0.26%) screws were replaced. No new and permanent neurological, vascular, or visceral complications were encountered. The free-hand technique for pedicle screw placement in the acceptable and safety zone in pedicles and vertebral bodies was 98%. No complications associated with screw insertion in growth were noted. The free-hand technique for pedicle screw placement can be safely used in patients at any age. The screw accuracy does not depend on the child's age nor the size of the deformity curve. Segmental instrumentation with posterior fixation in children with spinal deformities can be performed with a very low complication rate. Navigation of the robot is only an auxiliary tool in the hands of the surgeons, and the result of the work ultimately depends on the 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.

355 Robotic and Navigated Pedicle Screws Are Safer and More Accurate than Freehand Screws: A Systematic Review and Meta-Analysis

INTRODUCTION: Navigation and robotic pedicle screw placement systems have been developed to improve the accuracy of screw placement. However, the literature comparing the safety and accuracy of robotic and navigated screw placement with freehand screw placement in thoracolumbar spine surgery has been limited. METHODS: PubMed and EMBASE were systematically searched according to PRISMA guidelines. The search included indexed terms and text words from database inception to the date of the search (April 7th, 2022). Only randomized controlled trials comparing robotic assisted or navigated screws with fluoroscopic freehand screws in the thoracolumbar spine were included. Data and estimates were pooled using random-effects meta-analysis. Risk of bias was assessed using the Joanna Briggs Institute risk of bias tool. The main outcome measures were odds ratio estimates for screw accuracy according to the Gertzbein-Robbins scale and relative risk for various complications. RESULTS: A total of 14 papers encompassing 12 randomized controlled trials were identified. The pooled analysis demonstrated that robotic and navigated pedicle screw placement techniques were associated with increased odds of screw accuracy (OR 2.66, 95% CI 1.24-5.72, p = 0.0118). Robotic and navigated screw placement was associated with a lower risk of facet joint violations (RR 0.09, 95% CI 0.02-0.38, p = 0.0011) and major complications (RR 0.31, 95% CI 0.11-0.84, p = 0.0215). No differences were found in nerve root injury (RR 0.50, 95% CI 0.11-2.30, p = 0.3704), return to the operating room for screw revision (RR 0.28, 95% CI 0.07-1.13, p = 0.0744). CONCLUSIONS: These analyses suggest that robotic and navigated screw placement techniques are associated with higher odds of screw accuracy and superior safety profile compared to freehand techniques. Additional randomized controlled trials will be needed to further validate these findings.

PMMA Teeth-Pedicle Screw Spacers in Revision Spinal Surgery: A Technical Note

BACKGROUND Pedicle screw instrumentation was first described by Boucher in 1959 and subsequently popularised by Camille et al. in 1963. It has since become the most prevalent spinal fixation technique with indications for pedicle screw and rod constructs including congenital disease, trauma, infection, and spinal deformity including scoliosis. Initially used in lumbar spine surgery, the use of pedicle screws has since been extended to the thoracic spine where, because of the narrow pedicle corridor and proximity of critical structures, there is less margin for error in screw placement.1 Pedicle screw misplacement has been described in up to 40% of lumbar spine cases and up to 55% in thoracic spine cases.2 Complications associated with pedicle screw placement include damage to spinal cord, neural elements, nerve roots, pedicle fractures, wall cut out, and difficulty fitting instrumentation to the pedicle. Pedicle screw placement techniques can be grossly divided into freehand and image-guided techniques, with freehand techniques including drill assisted and pedicle gearshift (probe) methods while image-guided techniques incorporate fluoroscopic assisted, navigation assisted and robotic-assisted means. Pedicle screw placement into previously fused spines can be challenging with vital anatomic landmarks altered or obscured by the fusion mass.3 PMMA (Polymethyl methacrylate) was first introduced by Charnley in 1960 for cemented total hip arthroplasty. In spine surgery, PMMA has been used in numerous forms including kyphoplasty, disk substitution, and pedicle screw augmentation. In 1972 Bucholz and colleagues began combining PMMA with antibiotics to achieve high local antibiotic concentration in the setting of osteomyelitis; as such PMMA antibiotic loaded spacers have been well described in revision arthroplasty. Staged revision spinal surgery has been advocated by some authors in the setting of deep infection.4 Our senior author has noted that identification of pedicle screw tracts during second stage surgery can be challenging. Rationale We describe a novel surgical technique for the use of PMMA Teeth in the setting of staged revision spinal surgery to maintain the patency of pedicle screw tracts, permitting prompt identification on proceeding surgery stages and achieving local antibiotic delivery when necessary. Surgical Technique A standard posterior approach to the spine is performed identifying the in situ instrumentation. After removal of the in situ spinal rods and pedicle screws, the pedicle screw tracts are examined evaluating the medial, lateral, superior, and inferior walls of the tract. Residual fibrous tissue is debrided. A standard mix of Palacos R cement (Heraeus Medical, Newbury, UK) with the addition of 2 g vancomycin is performed. The PMMA teeth are subsequently fashioned from the Palacos R cement (Fig. 1). Similar to the technique described by Tsung et al.5 in revision hip arthroplasty, the principle for fixation is that of macroscopic fit as opposed to microscopic interlock of the cement; therefore, the PMMA teeth are inserted once the cement has cured.FIGURE 1: PMMA Teeth.PMMA indicates Polymethyl methacrylate.Expected Outcomes The PMMA teeth technique can assist the spinal surgeon in identifying the pedicle screw tract promptly and safely in staged revision spinal surgery with the added benefit of local antibiotic delivery. Complications Potential complications include PMMA Teeth fracture in situ, however, given the PMMA Teeth are inserted once the cement has cured, removal should be uncomplicated. DISCUSSION & CONCLUSION The incidence of revision spinal fusion has a reported range of 8 to 45%, with the revision rate increasing with follow-up; 21% of patients undergoing revision spinal surgery will require further spinal surgery.6 The rate of pedicle screw perforation has been reported to be as high as 28%, and 19% with a perforation greater than 2mm. This poses a significant challenge with considerable potential for pedicle screws to be misplaced in the revision spinal surgery setting.

Reduction in Radiation Exposure in Minimally Invasive Pedicle Screw Placement Using a Tubular Retractor: A Pilot Study

Percutaneous pedicle screw (PPS) placement is a minimally invasive spinal procedure that has been rapidly adopted over the last decade. However, PPS placement has elicited fear of increased radiation exposure from some surgeons, medical staff, and patients. This is because PPS placement is performed using a K-wire, and the operator must perform K-wire insertion into the pedicle under fluoroscopy. In order to prevent erroneous insertion, there are many occasions when direct insertion is required during radiation exposure, and the amount of radiation exposure to hands and fingers in particular increases. Although these problems are being addressed by navigation systems, these systems are still expensive and not widely available. Attempts have been made to address this situation using instrumentation commonly used in spinal surgery. First, it was considered to visualize anatomical bone markers using a tubular retractor and a microscope. In addition, the use of a self-drilling pin was adopted to locate the pedicle in a narrower field of view. Based on these considerations, a minimally invasive and highly accurate pedicle screw placement technique was developed while avoiding direct radiation exposure. This study evaluated radiation exposure and accuracy of pedicle screw placement using this new procedure in one-level, minimally invasive, transforaminal lumbar interbody fusion (MIS-TLIF). Data were collected retrospectively to review pedicle screw placement in single-level MIS TLIFs using a tubular retractor under a microscope. The total fluoroscopy time, radiation dose, and screw placement accuracy were reviewed. Extension of operating time was also evaluated. Twenty-four patients underwent single-level MIS TLIFs, with placement of 96 pedicle screws. There were 15 females and 9 males, with an average age of 64.8 years and a mean body mass index of 25.5 kg/m2. The mean operating time was 201.8 min. The mean fluoroscopic time was 26.8 s. The mean radiation dose of the area dose product was 0.0706 mGy∗m2. The mean radiation dose of air kerma was 6.0 mGy. The mean radiation dose of the entrance skin dose was 11.31 mGy. Postoperative computed tomography scans demonstrated 93 pedicle screws confined to the pedicle (97%) and three pedicle screw breaches (3.2%; two lateral, one medial). A patient with screw deviation of the medial pedicle wall developed right-foot numbness necessitating reoperation. There were no complications after reoperation. The average added time with this combined procedure was 39 min (range 16-69 min) per patient. This novel pedicle screw insertion technique compares favorably with other reports in terms of radiation exposure reduction and accuracy and is also useful from the viewpoint of avoiding direct radiation exposure to hands and fingers. It is economical because it uses existing spinal surgical instrumentation.

A quantitative accuracy assessment of the use of a rigid robotic arm in navigated placement of 726 pedicle screws

BackgroundTraditional minimally invasive fluoroscopy-based techniques for pedicle screw placement utilize guidance, which may require fluoroscopic shots. Computerized tomography (CT) navigation results in more accurate screw placement. Robotic surgery seeks to establish access and trajectory with greater accuracy.ObjectiveThis study evaluated the screw placement accuracy of a robotic platform.MethodsDemographic data, preoperative/postoperative CT scans, and complication rates of 127 patients who underwent lumbosacral pedicle screw placement with minimally invasive navigated robotic guidance using preoperative CT were analyzed.ResultsOn the GRS scale, 97.9% (711/726) of screws were graded A or B, 1.7% (12/726) of screws graded C, 0.4% (3/726) of screws graded D, and 0% graded E. Average offset from preoperative plan to final screw placement was 1.9 ± 1.5 mm from tip, 2.2 ± 1.4 mm from tail and 2.9 ± 2.3° of angulation.ConclusionsRobotic-assisted surgery utilizing preoperative CT workflow with intraoperative fluoroscopy-based registration improves pedicle screw placement accuracy within a patient’s pedicles.

Pedicle Screw Placement in Adolescent Idiopathic Scoliosis: A Comparison between Robotics Coupled with Navigation versus the Freehand Technique.

(1) Background: Robotics coupled with navigation (RAN) is a modern surgical platform shown to increase screw placement accuracy during pediatric scoliosis surgery. Our institution uses a technique which combines the RAN platform for apical pedicle screw placement and the freehand (FH) technique for terminal pedicle screw placement during scoliosis surgery (termed hybrid technique). We question if the complementary use of the RAN technology affects intraoperative outcomes, relative to the FH-only approach. (2) Methods: 60 adolescent idiopathic scoliosis (AIS) patients, ages 11–19 at surgery, who were operated on from 2019 through 2020 by a single surgeon, were retrospectively reviewed. Patients were separated by surgery type (hybrid RAN or FH), matched on demographic and surgical factors, and their intraoperative outcomes were compared statistically. (3) Results: Hybrid RAN patients had more screws placed (p = 0.01) and were of a higher BMI percentile (p = 0.005). Controlling for the number of screws placed, BMI%, and initial curve magnitude, there were no statistical differences in estimated blood loss per screw (p = 0.51), curve correction (p = 0.69), complications (p = 0.52), or fluoroscopy time (p = 0.88), between groups. However, operative time was two minutes longer per screw for hybrid RAN patients (p < 0.001). (4) Conclusions: Hybrid RAN surgeries took longer than FH, but yielded comparable effectiveness and safety as the FH technique during the initial RAN adoption phase.

Robotic-Assisted Lumbar Fusion: An Effective Technique for Pedicle Screw Placement.

Degenerative lumbar disease is a common condition in which progressive deterioration of the structures in the spine causes severely incapacitating pain and disability. Conservative management, including passive or active physical therapy, activity modification, and medications (eg, anti-inflammatory medications, oral and injectable steroids, opioids), may provide relief. However, when conservative management is unsuccessful or patients experience symptoms for an extended period of time, they may require spine surgery. Surgeons use a variety of techniques to perform lumbar fusion procedures with instrumentation, including open, percutaneous, minimally invasive, and robotic-assisted with navigation. The accuracy of pedicle-screw placement varies according to the technique used, and accuracy rates are high after robotic-assisted with navigation procedures. In addition, robotic-assisted spine procedures result in fewer infections than non-robotic-assisted spine procedures (P = .04). Perioperative nurses should understand basic lumbar spine anatomy, steps completed during robotic-assisted lumbar spine surgery, and the nursing considerations for patients undergoing this type of procedure.

Learning curve of thoracic pedicle screw fixation by freehand technique

Background: The freehand method of inserting thoracic pedicle screw has become one of the most popular techniques; however, data on its learning curve are scanty. The purpose of this study was to delineate the learning curve and to evaluate the safety of freehand technique of thoracic pedicle screw placement in nondeformed spine. Materials and Methods: A total of 92 consecutive patients who underwent thoracic posterior stabilization with pedicle screws using freehand technique between 2012 and 2017 in various pathologies of nondeformed spine from T1 to T10 at a single institution by a single surgeon were analyzed. Patients were divided into four quartiles (Q1, Q2, Q3, Q4, with 23 patients each) with each consecutive group serving as control for its prior. Demographics (age, sex, pathology involved) and complications were evaluated. Postoperative computed tomography (CT) scan was taken for evaluation of screws perforation including level, direction, grade, and severity of perforation. Results: Of total of 735 screws inserted in 92 patients, 72 screws were perforated with a perforation rate of 9.79%. Of the total perforations, more than half (63.88%) were of Grade 2 and maximum perforations were seen in the lateral direction (58.3%). Total three critical perforations were noted but none of them were symptomatic. The highest rate of perforation was evident at T4 vertebra (18.29%), whereas it was lowest at T9 (3.79%). The perforation rate showed a statistically significant (P < 0.05) decline in Q2 as compared to Q1 achieving asymptote in Q1 after approximately 80–100 screws. Conclusion: A steep learning curve is associated with the freehand technique of thoracic pedicle screws and asymptote can be achieved after approximately 80–100 screws. Novice surgeons can reduce the learning curve by doing practice on saw bone models and cadaveric dissection learning to avoid perforations and other complications with understanding the complex anatomy and variations encountered in the typical thoracic spine.

Using the lamina nutrient foramen as the entry point for posterior cervical pedicle screw placement

Study designA prospective study and technique description. ObjectiveThis study introduced a method for posterior cervical pedicle screw placement by using the bilateral posterior lamina nutrient foramens as the entry point. MethodsFirstly, 30 dry C3-C7 vertebrae specimens were harvested for measurement. The lamina nutrient foramens were used as the entry points for posterior cervical pedicle screw placement and four linear and two angle parameters were obtained from a computed tomography scan(CT). Then, 60 patients who underwent C3–C7 pedicle screw fixation using this method were included, linear and angle parameters were obtained from a postoperative CT. ResultsThe average incidences of lamina nutrient foramen on the C3–C7 specimens were 88.3%, 90.0%, 95.0%, 95.0%, and 96.7%, respectively. The distances from the entry point to the pedicle screw tip (OD), the pedicle transverse angles (α), and the pedicle sagittal angles (β) measure for the entry points from C3–C7 were 28.74 ± 3.45–30.15 ± 2.01 mm, 26.88 ± 6.89° to 32.72 ± 5.91°, and 12.48 ± 9.31° to 19.71 ± 8.45°, respectively, with no significant differences between the left and right sides. In the 60 patients who underwent surgery, the lengths of the pedicle screws (PL) were 28.34 ± 2.25–30.15 ± 2.31 mm, the pedicle transverse angles (α) were 26.89 ± 6.86° to 32.36 ± 5.65°, and the pedicle sagittal angles (β) were 12.49 ± 9.11° to 20.06 ± 8.91°. The new method had a 96.8% (454/469) success rate among these patients, with no screws penetrating the spinal canal or signs of vertebral artery injury. ConclusionEntry at the bilateral lamina nutrient foramen represents an alternative posterior cervical pedicle screw placement technique that is feasible and safe.

Novel Technique for Sacral-Alar-Iliac Screw Placement Using Three-Dimensional Patient-Specific Template Guide.

Introduction The sacral-alar-iliac (SAI) screw technique is becoming popular for sacropelvic fixation. However, appropriately placing SAI screws is technically demanding because of a narrow safe corridor and the risk of neurovascular/visceral injuries. Recently, a three-dimensional patient-specific template guiding technique for pedicle screw placement has been considered a promising method to improve accuracy and safety. The objective of the present study was to investigate the accuracy of SAI screw placement with a patient-specific template guide using cadaveric and prospective clinical pilot studies. Methods Three-dimensional planning of SAI screw placement, including entry point, screw trajectory, length, and diameter, was performed using a computer simulation software. Then, three-dimensional printed patient-specific template guides were created based on the plan. Firstly, a total of 12 SAI screws were placed for 6 cadaveric specimens using the guides. Next, in a prospective clinical trial, a total of 20 SAI screws were placed for 10 consecutively enrolled patients. The safety and accuracy of screw placement were analyzed using postoperative computed tomography by the evaluation of any cortical breach and measurement of screw deviations between the planned and actual screw positions. Results All the screws showed no perforation. In the cadaveric study, the mean horizontal and vertical deviations from the planned screw position at the entry point were 1.40±1.21 mm and 1.34±1.09 mm, respectively. The mean angular deviations in the sagittal and transverse planes were 1.68°±1.24° and 1.53°±1.06°, respectively. The results of the clinical study showed comparable accuracy with those of the cadaveric study, except for the vertical deviation at the entry point (p=0.048). Conclusions This is the first study to evaluate the feasibility and accuracy of using a patient-specific template guide for SAI screw placement. This technique could become an effective solution to achieve accurate screw placement.