Percutaneous Pedicle Screw Placement Research Articles

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.

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

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

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

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

Preoperative Robotics Planning Facilitates Complex Construct Design in Robot-Assisted Minimally Invasive Adult Spinal Deformity Surgery-A Preliminary Experience.

(1) Background: The correction of adult spinal deformity (ASD) can require long, complex constructs with multiple rods which traverse important biomechanical levels to achieve multi-pelvic fixation. Minimally invasive (MIS) placement of these constructs has historically been difficult. Advanced technologies such as spinal robotics platforms can facilitate the design and placement of these constructs and further enable these surgical approaches in MIS deformity surgery. (2) Methods: A retrospective study was performed on a series of ASD patients undergoing MIS deformity correction with ≥eight fusion levels to the lower thoracic spine with preoperative robotic construct planning and robot-assisted pedicle screw placement. (3) Results: There were 12 patients (10 female, mean age 68.6 years) with a diagnosis of either degenerative scoliosis (8 patients) or sagittal imbalance (4 patients). All underwent preoperative robotic planning to assist in MIS robot-assisted percutaneous or transfascial placement of pedicle and iliac screws with multiple-rod constructs. Mean operative values per patient were 9.9 levels instrumented (range 8-11), 3.9 interbody cages (range 2-6), 3.3 iliac fixation points (range 2-4), 3.3 rods (range 2-4), 18.7 screws (range 13-24), estimated blood loss 254 cc (range 150-350 cc), and operative time 347 min (range 242-442 min). All patients showed improvement in radiographic sagittal, and, if applicable, coronal parameters. Mean length of stay was 5.8 days with no ICU admissions. Ten patients ambulated on POD 1 or 2. Of 224 screws placed minimally invasively, four breaches were identified on intraoperative CT and repositioned (three lateral, one medial) for a robot-assisted screw accuracy of 98.2%. (4) Conclusions: Minimally invasive long-segment fixation for adult spinal deformity surgery has historically been considered laborious and technically intensive. Preoperative robotics planning facilitates the design and placement of even complex multi-rod multi-pelvic fixation for MIS deformity surgery.

An Integrated 3-Dimentional Navigation System Increases the Accuracy, Efficiency, and Safety of Percutaneous Thoracolumbar Pedicle Screw Placement in Minimally Invasive Approaches: A Randomized Cadaveric Study.

Cadaveric study. The purpose of this study was to compare a novel, integrated 3D navigational system (NAV) and conventional fluoroscopy in the accuracy, efficiency, and radiation exposure of thoracolumbar percutaneous pedicle screw (PPS) placement. Twelve skeletally mature cadaveric specimens were obtained for twelve individual surgeons. Each participant placed bilateral PS at 11 segments, from T8 to S1. Prior to insertion, surgeons were randomized to the sequence of techniques and the side (left or right). Following placement, a CT scan of the spine was obtained for each cadaver, and an independent reviewer assessed the accuracy of screw placement using the Gertzbein grading system. Outcome metrics of interest included a comparison of breach incidence/severity, screw placement time, total procedure time, and radiation exposure between the techniques. Bivariate statistics were employed to compare outcomes at each level. A total of 262 screws (131 using each technique) were placed. The incidence of cortical breaches was significantly lower with NAV compared to FG (9% vs 18%; P = .048). Of breaches with NAV, 25% were graded as moderate or severe compared to 39% in the FG subgroup (P = .034). Median time for screw placement was significantly lower with NAV (2.7 vs 4.1 min/screw; P = .012), exclusive of registration time. Cumulative radiation exposure to the surgeon was significantly lower for NAV-guided placement (9.4 vs 134 μGy, P = .02). The use of NAV significantly decreased the incidence of cortical breaches, the severity of screw breeches, screw placement time, and radiation exposure to the surgeon when compared to traditional FG.

Comparison of 3D-navigation and fluoroscopic guidance in percutaneous pedicle screw placement for traumatic fractures of the thoracolumbar junction

IntroductionFractures of the thoracolumbar junction are the most common vertebral fractures and can require surgical treatment. Several studies have shown that the accuracy of pedicle screw placement can be improved by the use of 3D-navigation. Still only few studies have focused on the use of navigation in traumatic spine injuries. Research questionThe aim of this study was to compare the screw placement accuracy and radiation exposure for 3D-navigated and fluoroscopy-guided percutaneous pedicle screw placement in traumatic fractures of the thoracolumbar junction. Materials and methodsIn this single-center study 25 patients undergoing 3D-navigated percutaneous pedicle screw placement for traumatic fractures of the thoracolumbar junction (T12-L2) were compared to a control group of 25 patients using fluoroscopy. Screw accuracy was determined in postoperative CT-scans using the Gertzbein-Robbins classification system. Additionally, duration of surgery, dose area product, fluoroscopy time and intraoperative complications were compared between the groups. ResultsThe accuracy of 3D-navigated percutaneous pedicle screw placement was 92.66 % while an accuracy of 88.08 % was achieved using standard fluoroscopy (p = 0.19). The fluoroscopy time was significantly less in the navigation group compared to the control group (p = 0.0002). There were no significant differences in radiation exposure, duration of surgery or intraoperative complications between the groups. Discussion and conclusionThe results suggest that 3D-navigation facilitates higher accuracy in percutaneous pedicle screw placement of traumatic fractures of the thoracolumbar junction, although limitations should be considered. In this study 3D-navigation did not increase fluoroscopy time, while radiation exposure and surgery time were comparable.

Assessing Procedural Accuracy in Lateral Spine Surgery: A Retrospective Analysis of Percutaneous Pedicle Screw Placement with Intraoperative CT Navigation.

Percutaneous pedicle screws (PPSs) are commonly used in posterior spinal fusion to treat spine conditions such as trauma, tumors, and degenerative diseases. Precise PPS placement is essential in preventing neurological complications and improving patient outcomes. Recent studies have suggested that intraoperative computed tomography (CT) navigation can reduce the dependence on extensive surgical expertise for achieving accurate PPS placement. However, more comprehensive documentation is needed regarding the procedural accuracy of lateral spine surgery (LSS). In this retrospective study, we investigated patients who underwent posterior instrumentation with PPSs in the thoracic to lumbar spine, utilizing an intraoperative CT navigation system, between April 2019 and September 2023. The system's methodology involved real-time CT-based guidance during PPS placement, ensuring precision. Our study included 170 patients (151 undergoing LLIF procedures and 19 trauma patients), resulting in 836 PPS placements. The overall PPS deviation rate, assessed using the Ravi scale, was 2.5%, with a notably higher incidence of deviations observed in the thoracic spine (7.4%) compared to the lumbar spine (1.9%). Interestingly, we found no statistically significant difference in screw deviation rates between upside and downside PPS placements. Regarding perioperative complications, three patients experienced issues related to intraoperative CT navigation. The observed higher rate of inaccuracies in the thoracic spine suggests that various factors may contribute to these differences in accuracy, including screw size and anatomical variations. Further research is required to refine PPS insertion techniques, particularly in the context of LSS. In conclusion, this retrospective study sheds light on the challenges associated with achieving precise PPS placement in the lateral decubitus position, with a significantly higher deviation rate observed in the thoracic spine compared to the lumbar spine. This study emphasizes the need for ongoing research to improve PPS insertion techniques, leading to enhanced patient outcomes in spine surgery.

Clinical application of percutaneous pedicle screw placement guided by ultrasound volume navigation combined with X-ray fluoroscopy: a prospective randomized controlled study

To explore the feasibility and accuracy of ultrasound volume navigation (UVN) combined with X-ray fluoroscopy-guided percutaneous pedicle screw implantation through a prospective randomized controlled study. Patients with thoracic and lumbar vertebral fractures scheduled for percutaneous pedicle screw fixation between January 2022 and January 2023 were enrolled. Among them, 60 patients met the selection criteria and were included in the study. There were 28 males and 32 females, with an average age of 49.5 years (range, 29-60 years). The cause of injury included 20 cases of traffic accidents, 21 cases of falls, 17 cases of slips, and 2 cases of heavy object impact. The interval from injury to hospital admission ranged from 1 to 5 days (mean, 1.57 days). The fracture located at T 12 in 15 cases, L 1 in 20 cases, L 2 in 19 cases, and L 3 in 6 cases. The study used each patient as their own control, randomly guiding pedicle screw implantation using UVN combined with X-ray fluoroscopy on one side of the vertebral body and the adjacent segment (trial group), while the other side was implanted under X-ray fluoroscopy (control group). A total of 4 screws and 2 rods were implanted in each patient. The implantation time and fluoroscopy frequency during implantation of each screw, angle deviation and distance deviation between actual and preoperative planned trajectory by imaging examination, and the occurrence of zygapophysial joint invasion were recorded. In terms of screw implantation time, fluoroscopy frequency, angle deviation, distance deviation, and incidence of zygapophysial joint invasion, the trial group showed superior results compared to the control group, and the differences were significant ( P<0.05). UVN combined with X-ray fluoroscopy-guided percutaneous pedicle screw implantation can yreduce screw implantation time, adjust dynamically, reduce operational difficulty, and reduce radiation damage.

Positioning accuracy and facet joints violation after percutaneous pedicle screws placement with robot-assisted versus fluoroscopy-guided technique: Systematic review and meta-analysis.

Minimally invasive spine surgery became the gold standard for the treatment of many spinal diseases. Only a few comparative studies were performed regarding the superiority of robotic-assisted (RA) surgery over fluoroscopic guidance (FG) surgery during percutaneous pedicle screws placement. Therefore, the aim of the present study was to conduct a systematic literature review and meta-analysis to evaluate the accuracy and potential advantages of RA compared with FG. This study is a systematic literature review conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. The review questions were formulated following the PICO scheme. Measured outcomes were presented using Forest plots. Heterogeneity among the included studies was assessed using the χ2 test, and the I2 statistic was utilized to estimate the proportion of total variation among the studies. A value exceeding 50% was considered indicative of substantial heterogeneity. Seven studies that met inclusion criteria were finally included in this meta-analysis. These seven studies include: 447 patients, 228 patients (931 screws) treated with robotic guide, and 219 patients (767 pedicle screws) using fluoroscopic guide, with a mean age of 55.2. The percentages of clinically acceptable screws were 94.3% in the robot-assisted group and 89% in the fluoroscopic guided group. The percentages of non-acceptable screws were 5.7% in the robot-assisted group and 11% in the fluoroscopic-guided group. Significant differences were observed between the two groups in terms of radiographic and clinical outcomes, with the robotic-assisted pedicle screw group exhibiting longer operative times. Robot technology serves as a valuable tool for assisting surgeons in challenging scenarios such as anatomical variants or patients with spinal deformities, ensuring accurate screw placement. The accuracy of pedicle screw placement with robotic technology is higher than with FG. In fact, the robotic approach allows significantly lower complication rates, fewer cases of violation of the proximal articular facet, less intraoperative exposure to radiation, even if it requires longer surgical times than the FG technique.

Navigated, percutaneous, three-step technique for lumbar and sacral screw placement: a novel, minimally invasive, and maximally safe strategy

BackgroundMinimally invasive spine surgery is a field of active and intense research. Image-guided percutaneous pedicle screw (PPS) placement is a valid alternative to the standard free-hand technique, thanks to technological advancements that provide potential improvement in accuracy and safety. Herein, we describe the clinical results of a surgical technique exploiting integration of neuronavigation and intraoperative neurophysiological monitoring (IONM) for minimally invasive PPS.Materials and MethodsAn intraoperative-computed tomography (CT)-based neuronavigation system was combined with IONM in a three-step technique for PPS. Clinical and radiological data were collected to evaluate the safety and efficacy of the procedure. The accuracy of PPS placement was classified according to the Gertzbein–Robbins scale.ResultsA total of 230 screws were placed in 49 patients. Only two screws were misplaced (0.8%); nevertheless, no clinical sign of radiculopathy was experienced by these patients. The majority of the screws (221, 96.1%) were classified as grade A according to Gertzbein–Robbins scale, seven screws were classified as grade B, one screw was classified as grade D, and one last screw was classified as grade E.ConclusionsThe proposed three-step, navigated, percutaneous procedure offers a safe and accurate alternative to traditional techniques for lumbar and sacral pedicle screw placement.Level of Evidence Level 3.Trial registration Not applicable.

Robot-assisted percutaneous pedicle screw placement accuracy compared with alternative guidance in lateral single-position surgery: a systematic review and meta-analysis.

While single-position surgery (SPS) eliminates the need for patient repositioning, the placement of screws in the unconventional lateral position poses unique challenges related to asymmetry relative to the surgical table. Use of robotic guidance or intraoperative navigation can help to overcome this. The aim of this study was to compare the relative accuracies offered by these various navigation modalities for pedicle screws placed in lateral SPS. According to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, the PubMed/Medline, Embase, and Cochrane Library databases were queried for studies reporting pedicle screw placement accuracy using fluoroscopic, CT-navigated, O-arm, or robotic guidance in lateral SPS, and a systematic review and meta-analysis was performed. Included studies all compared evaluated screw placement accuracy in lateral SPS using a single navigation method. Quality assessment was performed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system; risk of bias was assessed using the Newcastle-Ottawa Scale and the Joanna Briggs Institute checklist. The primary outcome, rate of pedicle screw breach, was analyzed using random-effects meta-analysis. Eleven studies were included comprising 548 patients who underwent the placement of instrumentation with 2488 screws. For the fluoroscopic, CT-navigated, O-arm, and robotic guidance cohorts, there were 3, 2, 3, and 3 studies, respectively. Breach rates by modality were as follows: fluoroscopic guidance (6.6%), CT navigation (4.7%), O-arm (3.9%), and robotic guidance (3.9%). Random-effects meta-analysis showed a significant difference between studies, with an overall breach rate of 4.9% (95% CI 3.1%-7.5%; p < 0.001); however, testing for subgroup differences failed to show a significant difference between guidance modalities (QM = 0.69, df = 3; p = 0.88). Heterogeneity between studies was significant (I2 = 79.0%, τ2 = 0.41, χ2 = 47.65, df = 10; p < 0.001). Robotic guidance of screws is noninferior to alternative guidance modalities in lateral SPS; however, additional prospective studies directly comparing different guidance types are merited.

Accuracy of percutaneous pedicle screw placement with 3-dimensional fluoroscopy-based navigation: Lateral decubitus position versus prone position

The accuracy of percutaneous pedicle screw (PSS) placement in the lateral decubitus position has seldom been reported. This study aimed to retrospectively compare the accuracy of PPS placement with 3-dimensional (3D) fluoroscopy-based navigation in 2 cohorts of patients who underwent surgery in the lateral decubitus or prone positions at our single institute. A total of 265 consecutive patients underwent spinal surgery with PPS from T1 (thoracic 1) to S (sacrum) under the 3D fluoroscopy-based navigation system at our institute. Patients were divided into 2 groups based on their intraoperative patient positioning: lateral decubitus (Group L) or prone (Group P). A total of 1816 PPSs were placed from T1 to S, and 76 (4.18%) PPSs were assessed as deviated PPS. Twenty-one of 453 (4.64%) PPSs in Group L deviation and 55 of 1363 (4.04%) PPSs in Group P had deviated PPS, but with not significant difference (P = .580). In Group L, although the PPS deviation rate was not significantly different between the upside and downside PPS, the downside PPS significantly deviated toward the lateral side compared with the upside PPS. The safety and efficacy of PPS insertion in the lateral decubitus position were similar to those in the conventional prone position.

Ultrasound-guided Jamshidi needle puncture to reduce radiation exposure during percutaneous pedicle screw placement: study protocol for a randomised controlled trial

IntroductionPercutaneous pedicle screw placement (PPSP) is a minimally invasive procedure highly dependent on fluoroscopic guidance, which results in increased radiation exposure and prolonged operative time. Ultrasound can image the lumbar...

A triple minimally invasive surgery combination for subacute osteoporotic lower lumbar vertebral collapse with neurological compromise: a potential alternative to the vertebral corpectomy/expandable cage strategy

Acute/subacute osteoporotic vertebral collapses (OVCs) in the lower lumbar spine with neurological compromise, although far less well documented than those in the thoracolumbar junction, may often pose greater treatment challenges. The authors clarified the utility of 3 familiar combined techniques of minimally invasive surgery for this condition as an alternative to the corpectomy/expandable cage strategy. This report included the authors' first 5 patients with more than 2 years (range 27-48 months) of follow-up. The patients were between 68 and 91 years of age, and had subacute painful L4 OVC with neurological compromise and preexisting lumbar spinal stenosis. The authors' single-stage minimally invasive surgery combination consisted of the following: step 1, balloon kyphoplasty for the L4 OVC to restore its strength, followed by L4-percutaneous pedicle screw (PPS) placement with patients in the prone position; step 2, tubular lateral lumbar interbody fusion (LLIF) at the adjacent disc space involved with endplate injury, with patients in the lateral position; and step 3, supplemental PPS-rod fixation with patients in the prone position. Estimated blood loss ranged from 20 to 72 mL. Neither balloon kyphoplasty-related nor LLIF-related potentially serious complications occurred. With CT measurements at the 9 LLIF levels, the postoperative increases averaged 3.5 mm in disc height and 3.7 mm in bilateral foraminal heights, which decreased by only 0.2 mm and 0 mm at the latest evaluation despite their low bone mineral densities, with a T-score of -3.8 to -2.6 SD. Canal compromise by fracture retropulsion decreased from 33% to 23% on average. As indicated by MRI measurements, the dural sac progressively enlarged and the ligamentum flavum increasingly shrank over time postoperatively, consistent with functional improvements assessed by the physician-based, patient-centered measures. The advantages of this method over the corpectomy/expandable cage strategy include the following: 1) better anterior column stability with a segmentally placed cage, which reduces stress concentration at the cage footplate-endplate interface as an important benefit for patients with low bone mineral density; 2) indirect decompression through ligamentotaxis caused by whole-segment spine lengthening with LLIF, pushing back both the retropulsed fragments and the disc bulge anteriorly and unbuckling the ligamentum flavum to diminish its volume posteriorly; and 3) eliminating the need for segmental vessel management and easily bleeding direct decompressions. The authors' recent procedural modification eliminated step 3 by performing loose PPS-rod connections in step 1 and their tight locking after LLIF in step 2, reducing to only once the number of times the patient was repositioned.

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.

Effect of angular correction during posterior instrumentation of spinal fractures on postoperative outcomes and quality of life.

Posterior instrumentation using pedicle screws and rods is the most commonly used technique for the treatment of thoracolumbar fractures of the spine. The procedure aims to restore the neurologic and biomechanical functions of the spine and allows for early mobilization and rapid reintegration into society. It is unclear whether the magnitude of correction has an effect on postoperative outcomes. We aimed to determine whether the magnitude of sagittal angular correction during posterior instrumentation of the spine had an effect on postoperative quality of life, pain and function outcomes as measured using the EQ5D-3L and the Core Outcome Measures Index (COMI) instruments. We also aimed to quantify the correlation between EQ5D-3L and COMI scores. We analyzed the pre- and postoperative radiographs of 52 patients who underwent percutaneous pedicle screw placement for thoracolumbar fractures, as well as their self-reported EQ5D-3L and COMI quality of life, pain and functional outcome scores. Regression models were constructed to estimate the effect that the magnitude of Cobb angle correction had on postoperative outcomes. We also estimated the correlation between EQ5D-3L and COMI scores. The median EQ5D-3L TTO score was 0.9 (range, -0.1 to 1). The median COMI score was 3.1 (range, 0 to 10). There was no significant effect of the magnitude of correction on EQ5d-3L TTO scores (p= 0.3379; R= 0.36) or on COMI scores (p= 0.3379; R= 0.15). Age and bone mineral density were not found to be significant predictors of outcome (p= 0.05). There was a strong correlation between the EQ5D-3L TTO and COMI scores (r=-0.62). The magnitude of Cobb angle correction during pedicle screw instrumentation of thoracolumbar fractures did not influence quality of life, pain or function outcomes. There was good correlation between EQ5D-3L TTO scores and COMI scores.

A Modified Method of Triggered Electromyography Monitoring in Minimally Invasive Spine Surgery: Comparison to Conventional Techniques and Correlation with Body Mass Index

Conventional triggered electromyography (EMG) in percutaneous pedicle screw (PPS) systems may be unreliable due to the interaction between the insertion apparatus and patient's soft tissue. Our aim was 1) to describe a modified technique of triggered EMG monitoring using insulated Kirschner wire (K-wires), 2) to compare EMG potentials with conventional techniques, and 3) to demonstrate the relationship between patient body mass index (BMI) and triggered EMG potentials. This was a prospective cross-sectional study of 50 patients undergoing minimally invasive PPS placement. Triggered EMG measurements using K-wires before and after insulation were compared. The difference between EMG measurements before and after insulation was correlated with patient BMI. A total of 50 patients, 22 females and 28 males, underwent triggered EMG testing using K-wires prior to final PPS placement in the thoracic and lumbosacral spine for a total of 472 triggered EMG measurements. When compared to standard triggered EMG monitoring, insulated triggered EMG monitoring demonstrated an average 55.4% decrease in EMG values (P < 0.001). Increasing BMI correlated to increasing % decrease in EMG values (r-coefficient, 0.376; P < 0.01). We describe a cost-effective, efficient, and reliable technique for triggered EMG during PPS placement which may help ensure accurate screw placement and minimize potentially devastating complications.

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

BackgroundThere 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.MethodsA 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.ResultsThere 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).ConclusionCompared 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.

Comparison of the Accuracy and Safety of TiRobot-Assisted and Fluoroscopy-Assisted Percutaneous Pedicle Screw Placement for the Treatment of Thoracolumbar Fractures.

Studies have compared the safety and accuracy of robot-assisted techniques for inserting conventional open pedicle screws for spinal surgery. However, no relevant studies have confirmed that robot-assisted percutaneous screw placement is better than fluoroscopic percutaneous screw placement for the treatment of thoracolumbar fractures. This study compared the accuracy and safety of TiRobot-assisted percutaneous pedicle screw placement with those of the fluoroscopy-assisted percutaneous technique for the treatment of thoracolumbar fractures. This retrospective study included 126 patients with thoracolumbar fractures who underwent percutaneous pedicle screw placement. Sixty-five patients were treated with the TiRobot-assisted technique and 61 patients were treated with the fluoroscopy-assisted technique. Patient demographics, accuracy of screw placement (according to the Gertzbein and Robbins scale of grades A to E), screw insertion angle, radiation exposure, surgical time, intraoperative blood loss, length of hospital stay, incision length, hospital expenses, surgical site infection, and neurological injury of the TiRobot-assisted and fluoroscopy-assisted groups were compared using Student's t-test, Pearson χ2 test, or Fisher's exact test. A total of 729 screws were placed (TiRobot-assisted group: 374 screws; fluoroscopy-assisted group: 355 screws). In the TiRobot-assisted group, 82.8% of screws were optimally positioned (grade A); however, the placement grades of the remaining screws were categorized as grade B (13.3%), grade C (3.2%), and grade D (0.5%). In the fluoroscopy-assisted group, 66.7% of the screws were optimally positioned (grade A); however, the placement grades of the remaining screws were categorized as grade B (21.4%), grade C (7.6%), grade D (3.6%), and grade E (0.5%). The proportion of clinically acceptable screws (grade A or B) was greater in the TiRobot-assisted group than in the fluoroscopy-assisted group. Additionally, the TiRobot-assisted group had a significantly larger mean screw insertion angle (22.27° ± 5.48° vs 20.55° ± 5.15°), larger incision length (13.86 ± 1.24 cm vs 12.77 ± 1.43 cm), and higher hospital expenses (69061.55 ± 7166.60 yuan vs 59383.85 ± 5019.64 yuan) than the fluoroscopy-assisted group. There were no significant differences in the intraoperative blood loss, length of hospital stay, and rates of surgical site infection and neurological injury in both groups (p > 0.05). However, the TiRobot-assisted group had significantly better surgical times, radiation times, and radiation exposure than the fluoroscopy-assisted group (p < 0.05). Percutaneous TiRobot-assisted pedicle screw placement is a safe, useful, and potentially more accurate alternative to the percutaneous fluoroscopy-assisted technique for treating thoracolumbar fractures.

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

BackgroundPercutaneous 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 methodsA 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.ResultsA 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).ConclusionsCTNav 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.