Navigated robot-guided pedicle screws placed successfully in single-position lateral lumbar interbody fusion

Beyond the Learning Curve of Robot-Assisted Navigation Spine Surgery: Refinement of Outcomes With Extended Experience

Objective This study assessed whether robotic-assisted navigation (RAN) spine surgery outcomes, including operative time and pedicle screw accuracy, continue to improve with extended experience beyond 200 cases. Methods This is a retrospective review of 60 patients who underwent lumbosacral transforaminal interbody fusion using RAN. Patients were segmented into three groups of 20 consecutive cases each. The first group represented a surgical performance baseline leading up to the investigating surgeon's 200th RAN case. The subsequent two groups were selected beyond the 200th case with an average of 15 cases between groups. Pedicle screw accuracy and intraoperative outcomes were assessed. Statistical results were significant if p<0.05. Results Measures of surgical efficiency significantly improved beyond the investigating surgeon's 200th RAN case. As case number increased, the following parameters significantly decreased: registration time (group 1: 16.9±6.5, group 2: 12.9±3.0, group 3: 8.7±1.6 minutes; p<0.05), screw insertion time (group 1: 14.9±3.5, group 2: 10.9±2.0, group 3: 8.4±2.7 minutes; p<0.05), and total operative time significantly decreased from group 1 (175.9±58.2 minutes) to group 2 (135.8±23.9 minutes) (p=0.013) with a non-significant decrease to group 3 (121.5±32.3 minutes). Accuracy (Grade = A) significantly increased across groups (group 1: 87%, group 2: 94%, group 3: 98%; p=0.024). Group 1 had the highest misplacement rate of 3.7% (4/108 screws). The overall misplacement rate was 1.4% (4/290 screws) (Grade C-E). There was a higher rate of lateral screw misplacement compared to medial misplacement. Conclusion Even with a small number of initial cases, RAN spine surgery can consistently be performed with high accuracy and acceptable intraoperative outcomes. However, this study demonstrated refined outcomes with extended robotic experience.

Efficacy and safety of navigation robot-assisted versus conventional oblique lateral lumbar interbody fusion with internal fixation in the treatment of lumbar degenerative diseases: A retrospective study

Effective internal fixation with pedicle screw is a key factor in the success of lumbar fusion with internal fixation. Whether navigation robots can improve the efficacy and safety of screw placement is controversial. Thirty-eight patients who underwent oblique lateral lumbar interbody fusion internal fixation from March 2022 to May 2023 were retrospectively analyzed, 16 cases in the navigational robot group and 22 cases in the fluoroscopy group. Using visual analog score (VAS) for the low back and lower limbs, Oswestry Disability Index to compare the clinical efficacy of the 2 groups; using perioperative indexes such as the duration of surgery, intraoperative blood loss, intraoperative fluoroscopy times, and postoperative hospital stay to compare the safety of the 2 groups; and using accuracy of pedicle screws (APS) and the facet joint violation (FJV) to compare the accuracy of the 2 groups. Postoperative follow-up at least 6 months, there was no statistically significant difference between the 2 groups in the baseline data (P > .05). The navigational robot group's VAS-back was significantly lower than the fluoroscopy group at 3 days postoperatively (P < .05). However, the differences between the 2 groups in VAS-back at 3 and 6 months postoperatively, and in VAS-leg and Oswestry Disability Index at 3 days, 3 months, and 6 months postoperatively were not significant (P > .05). Although duration of surgery in the navigational robot group was significantly longer than in the fluoroscopy group (P > .05), the intraoperative blood loss and the intraoperative fluoroscopy times were significantly lower than in the fluoroscopy group (P < .05). The difference in the PHS between the 2 groups was not significant (P > .05). The APS in the navigation robot group was significantly higher than in the fluoroscopy group, and the rate of FJV was significantly lower than in the fluoroscopy group (P < .05). Compared with the traditional fluoroscopic technique, navigation robot-assisted lumbar interbody fusion with internal fixation provides less postoperative low back pain in the short term, with less trauma, less bleeding, and lower radiation exposure, as well as better APS and lower FJV, resulting in better clinical efficacy and safety.

Investigation of the Usefulness of Implants With Locking Mechanisms for Diffuse Idiopathic Skeletal Hyperostosis (DISH)-Induced Thoracic and Lumbar Fractures in Patients Operated in the Prone Position

Background Diffuse idiopathic skeletal hyperostosis (DISH) is a disease that causes bone growth in the spine and musculoskeletal system, and even minor trauma can cause fractures that often require surgery. DISH-induced fractures show a tendency for bone loss when operated in the prone position, which can lead to poor fusion and implant failure; therefore, surgery in the lateral recumbent position is often recommended. However, inserting a pedicle screw (PS) in the lateral recumbent position is technically difficult. This study examined the effectiveness of the repair and fixation of thoracic and lumbar spine fractures using implants with locking mechanisms in the prone position in patients with DISH. Methods We retrospectively analyzed the data from 11 patients (six males and five females; mean age: 87 years) who underwent surgery for thoracic and lumbar fractures caused by DISH between December 2023 and June 2024. Surgery was performed in the prone position using PSs or transdiscal screws (TSDs) for DISH. Ennovate® implants manufactured by B-BRAUN were used. The fixed range was three above-three below for PSs and two above-two below for TSDs. The evaluation parameters were the height/level of injury, operative time, blood loss, local kyphosis angle, anterior wall height ratio, and complications. The local kyphosis angle was measured as the angle between the upper and lower endplates of the fractured vertebrae. The ratio of the anterior wall height was evaluated. Results The average operative time was 87 min (52-172 min), and the average blood loss was 40ml (10-140 ml). The preoperative and postoperative local kyphosis angle was -8.7° and -2.4°, respectively, and the average local kyphosis angle improvement was 6.3° (0.1-14°). The preoperative and postoperative anterior wall height ratio was 132% and 110%, respectively, and the average anterior wall height ratio improvement was 22% (2-82%). No complications, such as screw deviation, implant loosening, loss of correction, or skin problems, were observed. Conclusion This study demonstrated that DISH-induced thoracic and lumbar spine fractures could be repaired and fixed using implants with locking mechanisms in the prone position. The prone position is familiar to spine surgeons and is considered safe. Additionally, screw migration may occur due to decreased bone density in the vertebral bodies with DISH; in such cases, it would be better to fix the screw without forcing it to be repositioned.

Analysis of the Screw Accuracy and Postoperative Efficacy of Screw Placement in Single Position and Bipedal Position in Robot-Assisted Oblique Lumbar Interbody Fusion: Preliminary Results of Mazor X Stealth Usage

OBJECTIVE

Traditional manual OLIF combined with pedicle screw implantation has many problems of manual percutaneous screw implantation, such as high difficulty of screw placement, many fluoroscopies, long operation time, and many adjustments, resulting in greater trauma. The robot can perform various types of screw placement in the lateral recumbent position, which allows OLIF combined with posterior screw placement surgery to be completed in a single position. To compare the screw accuracy and initial postoperative results of oblique anterior lumbar fusion with robot-assisted screw placement in the lateral position and screw placement in the prone position for the treatment of lumbar spondylolisthesis.

METHODS

From May to June 2022, 45 patients with single-segment lumbar spondylolisthesis underwent Mazor X-assisted oblique lumbar fusion in one position and Renaissance-assisted surgery in two different positions, and screw accuracy was assessed on computed tomography scans according to a modified Gertzbein-Robbins classification. Patients were divided into a single position group and a bipedal position group (the lateral position for complete oblique lumbar fusion and then changed to the prone position for posterior screw placement), and the perioperative parameters, including operative time, number of fluoroscopies, and operative complications, were recorded separately. The results of the clinical indicators, such as the visual analog scale (VAS) for back and leg pain and the Oswestry Disability Index (ODI) score, were obtained.

RESULTS

There were no significant differences in the patients' demographic data between the two groups. The single position group had a shorter operative time and fewer fluoroscopies than the bipedal position group; the single position group had a higher percentage of screw accuracy at the A level than the bipedal position group, but there was no statistically significant difference between the two groups at the acceptable level (A + B) (p > 0.05). The single-position group had better outcomes at the 1-week postoperative follow-up back pain VAS scores (p < 0.05). There was no statistically significant difference in the postoperative leg pain VAS scores or the ODI scores when compared to the control group.

CONCLUSION

Robot-assisted lateral position oblique lumbar interbody fusion with pedicle screw placement has the same accuracy as prone positioning. Single position surgery can significantly shorten the operation time and reduce the fluoroscopy. There was no significant difference in the long-term efficacy between the two groups.

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.

Simultaneous Single-Position Lateral Lumbar Interbody Fusion Surgery and Unilateral Percutaneous Pedicle Screw Fixation for Spondylolisthesis

OBJECTIVE

To evaluate the clinical and radiological efficacy of a combine of lateral single screw-rod and unilateral percutaneous pedicle screw fixation (LSUP) for lateral lumbar interbody fusion (LLIF) in the treatment of spondylolisthesis.

METHODS

Sixty-two consecutive patients with lumbar spondylolisthesis who underwent minimally invasive (MIS)-TLIF with bilateral pedicle screw (BPS) or LLIF-LSUP were retrospectively studied. Segmental lordosis angle (SLA), lumbar lordosis angle (LLA), disc height (DH), slipping percentage, the cross-sectional areas (CSA) of the thecal sac, screw placement accuracy, fusion rate and foraminal height (FH) were used to evaluate radiographic changes postoperatively. Visual analogue scale (VAS) and Oswestry Disability Index (ODI) were used to evaluate the clinical efficacy.

RESULTS

Patients who underwent LLIF-LSUP showed shorter operating time, less length of hospital stay and lower blood loss than MIS-TLIF. No statistical difference was found between the 2 groups in screw placement accuracy, overall complications, VAS, and ODI. Compared with MIS-TLIF-BPS, LLIF-LSUP had a significant improvement in sagittal parameters including DH, FH, LLA, and SLA. The CSA of MIS-TLIF-BPS was significantly increased than that of LLIF-LSUP. The fusion rate of LLIF-LSUP was significantly higher than that of MIS-TLIF-BPS at the follow-up of 3 months postoperatively, but there was no statistical difference between the 2 groups at the follow-up of 6 months, 9 months, and 12 months.

CONCLUSION

The overall clinical outcomes and complications of LLIF-LSUP were comparable to that of MIS-TLIF-BPS in this series. Compared with MIS-TLIF-BPS, LLIF-LSUP for lumbar spondylolisthesis represents a significantly shorter operating time, hospital stay and lower blood loss, and demonstrates better radiological outcomes to maintain lumbar lordosis, and reveal an overwhelming superiority in the early fusion rate.

Single-Position Lateral Approach for Revision Thoracolumbar Corpectomy With Delayed Ipsilateral Kidney Atrophy: Technical Note and Discussion of Complications

Improvements in navigation technology have enabled surgeons to safely offer single-position fusion surgeries, demonstrating shorter operating times and reduced length of stay (LOS) as compared to traditional lateral and prone dual-position surgeries. However, no studies to date describe revision thoracolumbar corpectomy with simultaneous posterior rod removal and replacement in the lateral position. Furthermore, this is the first reported complication of delayed ipsilateral kidney atrophy following lateral lumbar surgery. A 56-year-old male patient with history of metastatic hepatocellular carcinoma and complex surgical history for a prior T12 pathologic fracture presented to the clinic for follow-up. Computed tomography (CT) demonstrated bilateral broken rods and subsidence of the T12 interbody cage, for which he underwent revision T12 corpectomy and posterior instrumentation revision via a single-position, left-sided lateral approach. Simultaneous exposure and removal of the broken rods enabled the placement of two short temporary rods between the T11-L1 screws posteriorly, allowing for rod distraction and the placement of the expandable corpectomy cage into the appropriate position. On follow-up cancer surveillance imaging, the left kidney became progressively atrophic within six months after surgery. According to a review of PubMed, Scopus, and Embase databases, we describe the first reported case of a single-position thoracolumbar revision corpectomy with simultaneous rod replacement. Of particular importance in this technique is the use of temporary rod placement for distraction across the index level to facilitate interbody cage placement. Furthermore, we discussed the first reported complication of delayed ipsilateral kidney atrophy following lateral lumbar fusion.

Single position robot-assisted pedicle screw placement with S2-alar-iliac fixation in lateral decubitus: cadaveric feasibility study and early clinical experience

OBJECTIVES

Single position lateral fusion with robotic assistance eliminates the need for surgical staging while harnessing the precision of robotic adjuncts. We expand on this technique by demonstrating the technical feasibility of placing bilateral pedicle screws with S2-alar-iliac (S2AI) fixation while in the lateral position.

METHODS

A cadaveric study was performed using 12 human specimens. A retrospective clinical series was also performed for patients who had undergone robot-assisted placement of S2AI screws in lateral decubitus between June 2020 and June 2022. Case demographics, implant placement time, implant size, screw accuracy, and complications were recorded. Early postoperative radiographic outcomes were reported.

RESULTS

In the cadaveric series, a total of 126 screws were placed with robotic assistance in 12 cadavers of which 24 screws were S2AI. There were four breaches from pedicle screws and none with S2AI screws for an overall accuracy rate of 96.8%. In the clinical series, four patients (all male, mean age 65.8 years) underwent single position lateral surgery with S2AI distal fixation. Mean BMI was 33.6 and mean follow-up was 20.5 months. Mean radiographic improvements were lumbar lordosis 12.3 ± 4.7°, sagittal vertical axis 1.5 ± 2.1 cm, pelvic tilt 8.5 ± 10.0°, and pelvic incidence-lumbar lordosis mismatch 12.3 ± 4.7°. A total of 42 screws were placed of which eight screws were S2AI. There were two breaches from pedicle screws and none from S2AI screws for an overall accuracy rate of 95.2%. No repositioning or salvage techniques were required for the S2AI screws.

CONCLUSIONS

We demonstrate here the technical feasibility of single position robot-assisted placement of S2-alar-iliac screws in the lateral decubitus position for single position surgery.

A Retrospective Analysis of Pedicle Screw Placement Accuracy Using the ExcelsiusGPS Robotic Guidance System: Case Series

BACKGROUND

Robotic guidance has become widespread in spine surgery. Although the intent is improved screw placement, further system-specific data are required to substantiate this intention for pedicle screws in spinal stabilization constructs.

OBJECTIVE

To determine the accuracy of pedicle screws placed with the aid of a robot in a cohort of patients immediately after the adoption of the robot-assisted surgery technique.

METHODS

A retrospective, Institutional Review Board-approved study was performed on the first 100 patients at a single facility, who had undergone spinal surgeries with the use of robotic techniques. Pedicle screw accuracy was graded using the Gertzbein-Robbins Scale based on pedicle wall breach, with grade A representing 0 mm breach and successive grades increasing breach thresholds by 2 mm increments. Preoperative and postoperative computed tomography scans were also used to assess offsets between the objective plan and true screw placements.

RESULTS

A total of 326 screws were analyzed among 72 patients with sufficient imaging data. Ages ranged from 21 to 84 years. The total accuracy rate based on the Gertzbein-Robbins Scale was 97.5%, and the rate for each grade is as follows: A, 82%; B, 15.5%; C, 1.5%; D, 1%; and E, 0. The average tip offset was 1.9 mm, the average tail offset was 2.0 mm, and the average angular offset was 2.6°.

CONCLUSION

Robotic-assisted surgery allowed for accurate implantation of pedicle screws on immediate adoption of this technique. There were no complications attributable to the robotic technique, and no hardware revisions were required.

Accuracy and digital screw path design of TiRobot-assisted pedicle screw placement for lumbar spondylolisthesis

PURPOSE

To investigate lumbar spondylolisthesis screw placement assisted by TiRobot in terms of digital screw path design, accurate implementation, and accuracy evaluation method.

METHODS

In this study, we enrolled 40 patients with lumbar spondylolisthesis between December 2020 and August 2021 who underwent spine surgery at the Affiliated Hospital of PuTian University. Pre-operative computed tomography position and screw path designation, intra-operative pedicle screw placement according to pre-operative planning, and post-operative evaluation of the accuracy of screw placement were performed. 3D coordinates of the entry and exit points before and after the operation were collected. The qualified points at different levels of accuracy were counted. The screw placement accuracy was based on the absolute difference using the Chi-squared test.

RESULTS

In total, 194 screws were successfully implanted with no screws penetrating the cortex. The absolute difference of entry points X, Y, and Z coordinates before and after the operation was 0.425 ± 0.294 mm, 0.417 ± 0.310 mm, and 0.466 ± 0.327 mm, respectively. The corresponding values in terms of exit points were 0.702 ± 0.470 mm, 0.963 ± 0.595mm, and 0.983 ± 0.566 mm, respectively. No obvious differences in coordinates before and after the operation were observed with an entry point degree of accuracy of ≥ 1.2 mm and exit point degree of accuracy of ≥ 2.1 mm. Therefore, the real surgery was consistent with the design.

CONCLUSIONS

TiRobot-assisted lumbar spondylolisthesis surgery achieved optimal path designation and precise surgery.

Lumbar plexus safe working zones with lateral lumbar interbody fusion: a systematic review and meta-analysis

PURPOSE

Significant risk of injury to the lumbar plexus and its departing motor and sensory nerves exists with lateral lumbar interbody fusion (LLIF). Several cadaveric and imaging studies have investigated the lumbar plexus position with respect to the vertebral body anteroposterior plane. To date, no systematic review and meta-analysis of the lumbar plexus safe working zones for LLIF has been performed.

METHODS

This systematic review was conducted according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Relevant studies reporting on the position of the lumbar plexus with relation to the vertebral body in the anteroposterior plane were identified from a PubMed database query. Quantitative analysis was performed using Welch's t test.

RESULTS

Eighteen studies were included, encompassing 1005 subjects and 2472 intervertebral levels. Eleven studies used supine magnetic resonance imaging (MRI) with in vivo subjects. Seven studies used cadavers, five of which performed dissection in the left lateral decubitus position. A significant correlation (p < 0.001) existed between anterior lumbar plexus displacement and evaluation with in vivo MRI at all levels between L1-L5 compared with cadaveric measurement. Supine position was also associated with significant (p < 0.001) anterior shift of the lumbar plexus at all levels between L1-L5.

CONCLUSIONS

This is the first comprehensive systematic review and meta-analysis of the lumbar neural components and safe working zones for LLIF. Our analysis suggests that the lumbar plexus is significantly displaced ventrally with the supine compared to lateral decubitus position, and that MRI may overestimate ventral encroachment of lumbar plexus.

Single-position circumferential lumbar spinal fusion: an overview of terminology, concepts, rationale and the current evidence base

PURPOSE

To provide definitions and a conceptual framework for single position surgery (SPS) applied to circumferential fusion of the lumbar spine.

METHODS

Narrative literature review and experts' opinion.

RESULTS

Two major limitations of lateral lumbar interbody fusion (LLIF) have been (a) a perceived need to reposition the patient to the prone position for posterior fixation, and (b) the lack of a robust solution for fusion at the L5/S1 level. Recently, two strategies for performing single-position circumferential lumbar spinal fusion have been described. The combination of anterior lumbar interbody fusion (ALIF) in the lateral decubitus position (LALIF), LLIF and percutaneous pedicle screw fixation (pPSF) in the lateral decubitus position is known as lateral single-position surgery (LSPS). Prone LLIF (PLLIF) involves transpsoas LLIF done in the prone position that is more familiar for surgeons to then implant pedicle screw fixation. This can be referred to as prone single-position surgery (PSPS). In this review, we describe the evolution of and rationale for single-position spinal surgery. Pertinent studies validating LSPS and PSPS are reviewed and future questions regarding the future of these techniques are posed. Lastly, we present an algorithm for single-position surgery that describes the utility of LALIF, LLIF and PLLIF in the treatment of patients requiring AP lumbar fusions.

CONCLUSIONS

Single position surgery in circumferential fusion of the lumbar spine includes posterior fixation in association with any of the following: lateral position LLIF, prone position LLIF, lateral position ALIF, and their combination (lateral position LLIF+ALIF). Preliminary studies have validated these methods.

Advanced Technologies for Outpatient Lumbar Fusion: Barriers and Opportunities

BACKGROUND

In recent years, there has been increasing interest in outpatient spine surgery. Minimally invasive techniques have created an opportunity for ambulatory lumbar fusion, and these techniques increasingly involve advanced technologies such as navigation and robotics.

OBJECTIVE

To explore the barriers, advantages, and future predictions for such technology in the context of outpatient lumbar fusions.

METHODS

This is a narrative review of studies examining the advantages, limitations, and cost-effectiveness of navigation and spinal robotics in conjunction with the outcomes and costs of outpatient lumbar fusion.

RESULTS

Outpatient lumbar fusion is a growing trend with ample evidence of its safety, favorable patient outcomes, and cost savings. Navigation and spinal robotics are associated with improved instrumentation accuracy and fewer complications, and the long-term cost savings can make these technologies financially practical in the outpatient setting. Future capabilities with robotics will only increase their value.

CONCLUSIONS

Advanced technologies such as navigation and robotics are strategic long-term investments in the context of outpatient lumbar fusion.

CLINICAL RELEVANCE

The favorable outcomes and costs associated with navigation and robotics will be relevant to any spine surgeon interested in developing an outpatient lumbar fusion program.

LEVEL OF EVIDENCE: 5

Robotic Spine Surgery: Past, Present, and Future

STUDY DESIGN

Systematic review.

OBJECTIVE

The aim of this review is to present an overview of robotic spine surgery (RSS) including its history, applications, limitations, and future directions.

SUMMARY OF BACKGROUND DATA

The first RSS platform received United States Food and Drug Administration approval in 2004. Since then, robotic-assisted placement of thoracolumbar pedicle screws has been extensively studied. More recently, expanded applications of RSS have been introduced and evaluated.

METHODS

A systematic search of the Cochrane, OVID-MEDLINE, and PubMed databases was performed for articles relevant to robotic spine surgery. Institutional review board approval was not needed.

RESULTS

The placement of thoracolumbar pedicle screws using RSS is safe and accurate and results in reduced radiation exposure for the surgeon and surgical team. Barriers to utilization exist including learning curve and large capital costs. Additional applications involving minimally invasive techniques, cervical pedicle screws, and deformity correction have emerged.

CONCLUSION

Interest in RSS continues to grow as the applications advance in parallel with image guidance systems and minimally invasive techniques.

IRB APPROVAL

N/A.

Lateral versus prone robot-assisted percutaneous pedicle screw placement: a CT-based comparative assessment of accuracy

OBJECTIVE

Single-position lateral lumbar interbody fusion (SP-LLIF) has recently gained significant popularity due to increased operative efficiency, but it remains technically challenging. Robot-assisted percutaneous pedicle screw (RA-PPS) placement can facilitate screw placement in the lateral position. The authors have reported their initial experience with SP-LLIF with RA-PPS placement in the lateral position, and they have compared this accuracy with that of RA-PPS placement in the prone position.

METHODS

The authors reviewed prospectively collected data from their first 100 lateral-position RA-PPSs. The authors graded screw accuracy on CT and compared it to the accuracy of all prone-position RA-PPS procedures during the same time period. The authors analyzed the effect of several demographic and perioperative metrics, as a whole and specifically for lateral-position RA-PPS placement.

RESULTS

The authors placed 99 lateral-position RA-PPSs by using the ExcelsiusGPS robotic platform in the first 18 consecutive patients who underwent SP-LLIF with postoperative CT imaging; these patients were compared with 346 prone-position RA-PPSs that were placed in the first consecutive 64 patients during the same time period. All screws were placed at L1 to S1. Overall, the lateral group had 14 breaches (14.1%) and the prone group had 25 breaches (7.2%) (p = 0.032). The lateral group had 5 breaches (5.1%) greater than 2 mm (grade C or worse), and the prone group had 4 (1.2%) (p = 0.015). The operative level had an effect on the breach rate, with breach rates (grade C or worse) of 7.1% at L3 and 2.8% at L4. Most breaches were grade B (< 2 mm) and lateral, and no breach had clinical sequelae or required revision. Within the lateral group, multivariate regression analysis demonstrated that BMI and number of levels affected accuracy, but the side that was positioned up or down did not.

CONCLUSIONS

RA-PPSs can improve the feasibility of SP-LLIF. Spine surgeons should be cautious and selective with this technique owing to decreased accuracy in the lateral position, particularly in obese patients. Further studies should compare SP-LLIF techniques performed while the patient is in the prone and lateral positions.

Setting for single position surgery: survey from expert spinal surgeons

PURPOSE

To describe a comprehensive setting of the different alternatives for performing a single position fusion surgery based on the opinion of leading surgeons in the field.

METHODS

Between April and May of 2021, a specifically designed two round survey was distributed by mail to a group of leaders in the field of Single Position Surgery (SPS). The questionnaire included a variety of domains which were focused on highlighting tips and recommendations regarding improving the efficiency of the performance of SPS. This includes operation room setting, positioning, use of technology, approach, retractors specific details, intraoperative neuromonitoring and tips for inserting percutaneous pedicle screws in the lateral position. It asked questions focused on Lateral Single Position Surgery (LSPS), Lateral ALIF (LA) and Prone Lateral Surgery (PLS). Strong agreement was defined as an agreement of more than 80% of surgeons for each specific question. The number of surgeries performed in SPS by each surgeon was used as an indirect element to aid in exhibiting the expertise of the surgeons being surveyed.

RESULTS

Twenty-four surgeons completed both rounds of the questionnaire. Moderate or strong agreement was found for more than 50% of the items. A definition for Single Position Surgery and a step-by-step recommendation workflow was built to create a better understanding of surgeons who are starting the learning curve in this technique.

CONCLUSION

A recommendation of the setting for performing single position fusion surgery procedure (LSPS, LA and PLS) was developed based on a survey of leaders in the field.

Single-Position Fluoroscopy-Guided Lateral Lumbar Interbody Fusion With Intraoperative Computed Tomography-Navigated Posterior Pedicle Screw Fixation: Technical Report and Literature Review

Lateral lumbar interbody fusion (LLIF) is a powerful tool in minimally invasive spine surgery with high rates of fusion, excellent indirect decompression, and deformity correction. LLIF offers advantages compared with anterior lumbar interbody fusion including a more favorable complication profile. Traditionally, the interbody fusion is performed in the lateral position and fluoroscopy-assisted pedicle screw fixation performed with the patient repositioned prone. The evolution of both pedicle screw technology and intraoperative navigation has enhanced the feasibility of single (lateral)-position surgery. Early reports using fluoroscopy-assisted pedicle screws and computer or robotic navigation suggest this technique can be performed safely and accurately. The purpose of this brief report is to provide the technical steps, workflow, as well as pearls and pitfalls for single-position LLIF with true intraoperative computed tomography navigation-guided percutaneous pedicle screw fixation. A case example is included for illustration.

Single Position Lateral Lumbar Interbody Fusion With Posterior Instrumentation Utilizing Computer Navigation and Robotic Assistance: Retrospective case review and surgical technique considerations

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To determine safety and short-term outcomes of single-position lateral lumbar interbody fusion (LLIF) with bilateral posterior instrumentation and robotic assistance. The article also describes surgical technique considerations for the procedure.

METHODS

20 patients underwent single-position LLIF with posterior instrumentation and robotic assistance. The patients were followed for a minimum of 3 months post-operatively.

RESULTS

Average operative time was 211 ± 34 minutes, average blood loss was 51.25 ± 17 cc's, and average length of stay was 1.4 ± .75 days. There were no intraoperative complications, readmissions, revision surgeries, and no incidence of hardware malposition. Significant improvement in pain and ODI scores was noted at 3 month follow up.

CONCLUSIONS

The study demonstrated safety and short-term clinical efficacy of minimally invasive single-position lateral lumbar interbody fusion with bilateral posterior instrumentation utilizing robotic assistance and navigation. There are certain surgical technique considerations that must be followed to ensure optimal surgical workflow and predictable outcomes.

Comparative Analysis of Optoelectronic Accuracy in the Laboratory Setting Versus Clinical Operative Environment: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVES

The optoelectronic camera source and data interpolation process serve as the foundation for navigational integrity in robotic-assisted surgical platforms. The current systematic review serves to provide a basis for the numerical disparity observed when comparing the intrinsic accuracy of optoelectronic cameras versus accuracy in the laboratory setting and clinical operative environments.

METHODS

Review of the PubMed and Cochrane Library research databases was performed. The exhaustive literature compilation obtained was then vetted to reduce redundancies and categorized into topics of intrinsic accuracy, registration accuracy, musculoskeletal kinematic platforms, and clinical operative platforms.

RESULTS

A total of 465 references were vetted and 137 comprise the basis for the current analysis. Regardless of application, the common denominators affecting overall optoelectronic accuracy are intrinsic accuracy, registration accuracy, and application accuracy. Intrinsic accuracy equaled or was less than 0.1 mm translation and 0.1 degrees rotation per fiducial. Controlled laboratory platforms reported 0.1 to 0.5 mm translation and 0.1 to 1.0 degrees rotation per array. Accuracy in robotic-assisted spinal surgery reported 1.5 to 6.0 mm translation and 1.5 to 5.0 degrees rotation when comparing planned to final implant position.

CONCLUSIONS

Navigational integrity and maintenance of fidelity of optoelectronic data is the cornerstone of robotic-assisted spinal surgery. Transitioning from controlled laboratory to clinical operative environments requires an increased number of steps in the optoelectronic kinematic chain and error potential. Diligence in planning, fiducial positioning, system registration and intra-operative workflow have the potential to improve accuracy and decrease disparity between planned and final implant position.

Single position lumbar fusion: a systematic review and meta-analysis

BACKGROUND CONTEXT

Recently, a single position lumbar fusion has been described in which both the anterior or lateral interbody fusion as well as posterior percutaneous pedicle screw fixation are performed in a single position.

PURPOSE

The purpose of this study was to present and analyze the current evidence for single position lumbar fusion.

STUDY DESIGN/SETTING

This is a systematic review and meta-analysis.

PATIENT SAMPLE

Prospective or retrospective studies published in English that assessed outcomes of single position lumbar fusion surgery for patients with lumbar degenerative disease, spondylolisthesis, or radiculopathy were included.

OUTCOME MEASURES

Outcome measures included operative time, estimated blood loss, hospital length of stay, X-Ray exposure time, and postoperative outcomes including leg numbness or pain, leg weakness, lumbar lordosis, and segmental lordosis.

METHODS

This systematic review was performed in accordance with PRISMA guidelines. Two separate meta-analyses were performed. The first compared single position (SP) surgery, both lateral and prone, to dual position or flipped (F) surgery. The second meta-analysis compared lateral single position (LSP) surgery to prone single position (PSP) surgery. Variables were included if (1) they were a mean with a reported standard deviation or (2) if they were a categorical variable. For calculating standard error of the mean, we used sample size, mean, and standard deviation. A random effects model was used. The heterogeneity among studies was assessed with a significance level of <0.05.

RESULTS

Twenty-one articles were included for analysis. Three studies were prospective nonrandomized studies, while 18 were retrospective. Seven articles studied lateral single position only, 10 articles compared lateral single position to traditional repositioning surgery, three articles studied prone single position surgery, and one article compared prone single position surgery to traditional repositioning surgery. A detailed review is provided for all 21 articles. Seventeen studies were included for meta-analysis comparing the SP versus F groups, for a total of 942 patients in the SP group and 254 in the F group. Mean operative time was significantly less for the SP group compared with the F group (SP: 127.5±7.9, F: 188.7±15.5, p<.001). Average hospital length of stay was 2.87±0.3 days in the SP group and 6.63±0.6 days in the F group (p<.001). Complication rates did not significantly differ between groups. Pedicle screws placed in the lateral position had a higher rate of complication as compared with those placed in a prone position (L: 10.2±2%, P: 1.6±1%, p=.015). Seventeen studies were included in the LSP versus PSP analysis, including 13 in the LSP group and four in the PSP group, with a total of 785 patients in the LSP group and 85 patients in the PSP group. Operative time and X-Ray exposure was significantly less in the LSP compared with the PSP group (117.1±5.5 minutes vs. 166.9±21.9 minutes, p<.001; 43.7±15.5 minutes vs. 171.0±25.8 minutes, p<.001). Postoperative segmental lordosis was greater in the prone single position group (p<.001).

CONCLUSIONS

Single position surgery decreases operative times and hospital length of stay, while maintaining similar complication rates and radiographic outcomes. PSP surgery was found to be longer in duration and have increased radiation exposure time compared with LSP, while increasing postoperative segmental lordosis.

Evolution of Complex Spine Surgery in Neurosurgery: From Big to Minimally Invasive Surgery for the Treatment of Spinal Deformity

Spinal instrumentation for adult spinal deformity dates back to the surgical correction of secondary complications from infectious processes, such as Pott's disease and poliomyelitis [1]. With the population aging at a longer life expectancy today, advanced degenerative spinal diseases and idiopathic scoliosis supersede as the most common causes of adult spinal deformity. Correction of the thoracolumbar malignment, specifically, has rapidly evolved with the burgeoning success of spinal instrumentation. The objective of this chapter is to review the metamorphosis of operative principles for adult thoracolumbar deformity, from aggressive osteotomies in the posterior bony elements to minimally invasive surgery (MIS) at the intervertebral disc space.

State of the art review of new technologies in spine deformity surgery-robotics and navigation

STUDY DESIGN/METHODS

Review article.

OBJECTIVES

The goal of this article is to review the available evidence for computerized navigation and robotics as an accuracy improvement tool for spinal deformity surgery, as well as to consider potential complications, impact on clinical outcomes, radiation exposure, and costs. Pedicle screw and rod construct are widely utilized for posterior spinal fixation in spinal deformity correction. Freehand placement of pedicle screws has long been utilized, although there is variable potential for inaccuracy depending on surgeon skill and experience. Malpositioned pedicle screws may have significant clinical implications ranging from nerve root irritation, inadequate fixation, CSF leak, perforation of the great vessels, or spinal cord damage. Computer-based navigation and robotics systems were developed to improve pedicle screw insertion accuracy and consistency, and decrease the risk of malpositioned pedicle fixation. The available evidence suggests that computer-based navigation and robotic-assisted guidance systems for pedicle cannulation are at least equivalent, and in several reports superior, to freehand techniques in terms of accuracy. CT and robotic navigation systems do appear to decrease radiation exposure to the operative team in some reports. Published reports do indicate longer operative times with use of robotic navigation compared with traditional freehand techniques for pedicle screw placement. To date, there is no conclusive evidence that use of CT or robotic navigation has any measurable impact on patient outcomes or overall complication reduction. There are theoretical advantages with robotic and CT navigation in terms of both speed and accuracy for severe spinal deformity or complex revision cases, however, there is a need for studies to investigate this technology in these specific cases. There is no evidence to date demonstrating the cost effectiveness of CT or robotic navigation as compared with traditional pedicle cannulation techniques.

CONCLUSIONS

The review of available evidence suggests that computer-based navigation and robotic-assisted guidance systems for pedicle cannulation are at least equivalent, and in several reports superior, to freehand techniques in terms of radiographic accuracy. There is no current clinical evidence that the use of navigation or robotic techniques leads to improved patient outcomes or decreased overall complications or reoperation rates, and the use of these systems may substantially increase surgical costs.

LEVEL OF EVIDENCE

V.

Does robot-assisted navigation influence pedicle screw selection and accuracy in minimally invasive spine surgery?

OBJECTIVE

The accuracy of percutaneous pedicle screw placement has increased with the advent of robotic and surgical navigation technologies. However, the effect of robotic intraoperative screw size and trajectory templating remains unclear. The purpose of this study was to compare pedicle screw sizes and accuracy of placement using robotic navigation (RN) versus skin-based intraoperative navigation (ION) alone in minimally invasive lumbar fusion procedures.

METHODS

A retrospective cohort study was conducted using a single-institution registry of spine procedures performed over a 4-year period. Patients who underwent 1- or 2-level primary or revision minimally invasive surgery (MIS)–transforaminal lumbar interbody fusion (TLIF) with pedicle screw placement, via either robotic assistance or surgical navigation alone, were included. Demographic, surgical, and radiographic data were collected. Pedicle screw type, quantity, length, diameter, and the presence of endplate breach or facet joint violation were assessed. Statistical analysis using the Student t-test and chi-square test was performed to evaluate the differences in pedicle screw sizes and the accuracy of placement between both groups.

RESULTS

Overall, 222 patients were included, of whom 92 underwent RN and 130 underwent ION MIS-TLIF. A total of 403 and 534 pedicle screws were placed with RN and ION, respectively. The mean screw diameters were 7.25 ± 0.81 mm and 6.72 ± 0.49 mm (p < 0.001) for the RN and ION groups, respectively. The mean screw length was 48.4 ± 4.48 mm in the RN group and 45.6 ± 3.46 mm in the ION group (p < 0.001). The rates of “ideal” pedicle screws in the RN and ION groups were comparable at 88.5% and 88.4% (p = 0.969), respectively. The overall screw placement was also similar. The RN cohort had 63.7% screws rated as good and 31.4% as acceptable, while 66.1% of ION-placed screws had good placement and 28.7% had acceptable placement (p = 0.661 and p = 0.595, respectively). There was a significant reduction in high-grade breaches in the RN group (0%, n = 0) compared with the ION group (1.2%, n = 17, p = 0.05).

CONCLUSIONS

The results of this study suggest that robotic assistance allows for placement of screws with greater screw diameter and length compared with surgical navigation alone, although with similarly high accuracy. These findings have implied that robotic platforms may allow for safe placement of the “optimal screw,” maximizing construct stability and, thus, the ability to obtain a successful fusion.

Robotic navigation in spine surgery: Where are we now and where are we going?

Robotic navigation is a new and rapidly emerging niche within minimally invasive spine surgery. The robotic arms-race began in 2004 and has resulted in no less than four major robotic surgical adjuncts. Current Food and Drug Administration (FDA)-approved applications of robotic navigation are limited to pedicle screw instrumentation, but new indications and experimental applications are rapidly emerging. As with any new technology, robotic navigation must be vetted for clinical efficacy, efficiency, safety, and cost-effectiveness. Given the rapid advancements made on a yearly basis, it is important to make frequent and objective assessments of the available technology. Thus, the authors seek to provide the most up-to-date review of the history, currently available technology, learning curve, novel applications, and cost effectiveness of today's available robotic systems as it relates to spine surgery.

Image Guidance in Spinal Surgery: A Critical Appraisal and Future Directions

BACKGROUND

Image-guided spinal surgery (IGSS) underwent rapid development over the past decades. The goal of IGSS is to increase patient safety and improve workflow. We present an overview of the history of IGSS, illustrate its current state, and highlight future developments. Currently, IGSS requires an image set, a tracking system, and a calibration method.

IMAGING

Two-dimensional images have many disadvantages as a source for navigation. Currently, the most common navigation technique is three-dimensional (3D) navigation based on cross-sectional imaging techniques such as cone-beam computed tomography (CT) or fan-beam CT.

TRACKING

Electromagnetic tracking uses an electromagnetic field to localize instruments. Optical tracking using infrared cameras has currently become one of the most common tracking methods in IGSS.

CALIBRATION

The three most common techniques currently used are the point-matching registration technique, the surface-matching registration technique, and the automated registration technique.

FUTURE

Augmented reality (AR) describes a computer-generated image that can be superimposed onto the real-world environment. Marking pathologies and anatomical landmarks are a few examples of many possible future applications. Additionally, AR offers a wide range of possibilities in surgical training. The latest development in IGSS is robotic-assisted surgery (RAS). The presently available data on RAS are very encouraging, but further improvements of these procedures is expected.

CONCLUSION

IGSS significantly evolved since its inception and is becoming a routinely used technology. In the future, IGSS will combine the advantages of "active/freehand 3D navigation" with AR and RAS and will one day find its way into all aspects of spinal surgery, not only in instrumented procedures.

Less Invasive Pediatric Spinal Deformity Surgery: The Case for Robotic-Assisted Placement of Pedicle Screws

Introduction: Pediatric spinal deformity involves a complex 3-dimensional (3D) deformity that increases the risk of pedicle screw placement due to the close proximity of neurovascular structures. To increase screw accuracy, improve patient safety, and minimize surgical complications, the placement of pedicle screws is evolving from freehand techniques to computer-assisted navigation and to the introduction of robotic-assisted placement. Purpose: The aim of this review was to review the current literature on the use of robotic navigation in pediatric spinal deformity surgery to provide both an error analysis of these techniques and to provide recommendations to ensure its safe application. Methods: A narrative review was conducted in April 2021 using the MEDLINE (PubMed) database. Studies were included if they were peer-reviewed retrospective or prospective studies, included pediatric patients, included a primary diagnosis of pediatric spine deformity, utilized robotic-assisted spinal surgery techniques, and reported thoracic or lumbar pedicle screw breach rates or pedicle screw malpositioning. Results: In the few studies published on the use of robotic techniques in pediatric spinal deformity surgery, several found associations between the technology and increased rates of screw placement accuracy, reduced rates of breach, and minimal complications. All were retrospective studies. Conclusions: Current literature is of a low level of evidence; nonetheless, the findings suggest the accuracy and safety of robotic-assisted spinal surgery in pediatric pedicle screw placement. The introduction of robotics may drive further advances in less invasive pediatric spinal deformity surgery. Further study is warranted.

Accuracy of Robotic-Assisted Spinal Surgery-Comparison to TJR Robotics, da Vinci Robotics, and Optoelectronic Laboratory Robotics

BACKGROUND

The optoelectronic camera source and data interpolation serve as the foundation for navigational integrity in the robotic-assisted surgical platform. The objective of the current systematic review serves to provide a basis for the numerical disparity that exists when comparing the intrinsic accuracy of optoelectronic cameras: accuracy observed in the laboratory setting versus accuracy in the clinical operative environment. It is postulated that there exists a greater number of connections in the optoelectronic kinematic chain when analyzing the clinical operative environment to the laboratory setting. This increase in data interpolation, coupled with intraoperative workflow challenges, reduces the degree of accuracy based on surgical application and to that observed in controlled musculoskeletal kinematic laboratory investigations.

METHODS

Review of the PubMed and Cochrane Library research databases was performed. The exhaustive literature compilation obtained was then vetted to reduce redundancies and categorized into topics of intrinsic optoelectronic accuracy, registration accuracy, musculoskeletal kinematic platforms, and clinical operative platforms.

RESULTS

A total of 147 references make up the basis for the current analysis. Regardless of application, the common denominators affecting overall optoelectronic accuracy are intrinsic accuracy, registration accuracy, and application accuracy. Intrinsic accuracy of optoelectronic tracking equaled or was less than 0.1 mm of translation and 0.1° of rotation per fiducial. Controlled laboratory platforms reported 0.1 to 0.5 mm of translation and 0.1°-1.0° of rotation per array. There is a huge falloff in clinical applications: accuracy in robotic-assisted spinal surgery reported 1.5 to 6.0 mm of translation and 1.5° to 5.0° of rotation when comparing planned to final implant position. Total Joint Robotics and da Vinci urologic robotics computed accuracy, as predicted, lies between these two extremes-1.02 mm for da Vinci and 2 mm for MAKO.

CONCLUSIONS

Navigational integrity and maintenance of fidelity of optoelectronic data is the cornerstone of robotic-assisted spinal surgery. Transitioning from controlled laboratory to clinical operative environments requires an increased number of steps in the optoelectronic kinematic chain and error potential. Diligence in planning, fiducial positioning, system registration, and intraoperative workflow have the potential to improve accuracy and decrease disparity between planned and final implant position. The key determining factors limiting navigation resolution accuracy are highlighted by this Cochrane research analysis.

Simultaneous Robotic Single Position Oblique Lumbar Interbody Fusion With Bilateral Sacropelvic Fixation in Lateral Decubitus

Single position lateral fusion reduces the need for a secondary surgery and robotic guidance allows for potentially higher accuracy of screw placement. We expand the role of robotics with a simultaneous workflow where 2 surgeons can work in single position surgery and discuss the technical feasibility of placement of S2-alar-iliac (S2AI) screws in the lateral position. A 70-year-old male presented with chronic back pain and bilateral leg pain with the left side worse than the right. He subsequently underwent an L3–S1 oblique lumbar interbody fusion (OLIF) with a minimally invasive L3-ilium robotic posterior spinal fixation simultaneously in single lateral position with S2AI screws. The software planning requisite of robotics allowed for a preoperative plan where lumbar cortical screws were used to line up with bilateral S2AI screws. Intraoperatively, the OLIF was performed anterior to the patient which allowed for a second surgeon to perform the posterior stage of screw placement simultaneously in overlapping fashion during OLIF exposure. Once all screws were placed, the OLIF discectomy and cage placement were completed. As the OLIF incision is closed, rodding proceeds posteriorly with subsequent closure simultaneously as well. Operative time from skin incision to skin closure was 3 hours and 47 minutes. We present here a novel technical report on the recommended workflow of simultaneous robotic single position surgery OLIF and demonstrate the feasibility of placement of sacroiliac fixation in the lateral decubitus position. We believe this technique to be minimally invasive, effective, with the benefit of shortening valuable operating room case time.

Robotics in spine surgery: A systematic review

Robotic systems to assist with pedicle screw placement have recently emerged in the field of spine surgery. Here, the authors systematically reviewed the literature for evidence of these robotic systems and their utility. Thirty-four studies that reported the use of spinal instrumentation with robotic assistance and met inclusion criteria were identified. The outcome measures gathered included: pedicle screw accuracy, indications for surgery, rates of conversion to an alternative surgical method, radiation exposure, and learning curve. In our search there were five different robotic systems identified. All studies reported accuracy and the most commonly used accuracy grading scale was the Gertzbein Robbins scale (GRS). Accuracy of clinically acceptable pedicle screws, defined as < 2 mm cortical breech, ranged from 80% to 100%. Many studies categorized indications for robotic surgery with the most common being degenerative entities. Some studies reported rates of conversion from robotic assistance to manual instrumentation due to many reasons, with robotic failure as the most common. Radiation exposure data revealed a majority of studies reported less radiation using robotic systems. Studies looking at a learning curve effect with surgeon use of robotic assistance were not consistent across the literature. Robotic systems for assistance in spine surgery have continued to improve and the accuracy of pedicle screw placement remains superior when compared to free-hand technique, however rates of manual conversion are significant. Currently, these systems are successfully employed in various pathological entities where trained spine surgeons can be safe and accurate regardless of robotic training.

Intraoperative image guidance for lateral position surgery

Recent advances in minimally invasive spine surgery techniques have precipitated the popularity of lateral position spine surgery, such as lateral lumbar interbody fusion (LLIF) and oblique lumbar interbody fusion (OLIF). Lateral position surgery offers a unique, minimally invasive approach to the lumbar spine that allows for preservation of anterior and posterior spinal elements. Traditionally, surgeons have relied upon fluoroscopy for triangulation and implant placement. Over the last decade, intraoperative 3-dimensional navigation (ION) has risen to the forefront of innovation in LLIF and OLIF. This technology utilizes intra-operative advanced imaging, such as comminuted tomography (CT), to map the patient’s 3D anatomy and allows the surgeon to accurately visualize instruments and implants in spatial relationship to the patient’s anatomy in real time. ION has the potential to improve accuracy during instrumentation, decrease operating room times, lower radiation exposure to the surgeon and staff, and increase feasibility of single-position surgery during which the spine is instrumented both laterally and posteriorly while the patient remains in the lateral decubitus position. Despite the advantages of ION, the intra-operative radiation exposure risk to patients is controversial. Future directions include continued innovation in ultra low radiation imaging (ULRI) techniques and image enhancement technology and in uses of robot-assisted navigation in single-position spine surgery.

Initial intraoperative experience with robotic-assisted pedicle screw placement with stealth navigation in pediatric spine deformity: an evaluation of the first 40 cases

Pedicle screw fixation in pediatric spine surgery has become common practice given the fixation stability and improved curve correction. However, due to proximity to vital structures, accuracy is paramount. Literature has reported accuracy rates from 87.5 to 90% using traditional freehand techniques. This study presents our initial experience with pedicle screw placement using the newest generation of spinal robotics for treatment of pediatric spinal deformity. A cohort of patients, aged 8-21 years, undergoing spinal fusion surgery using robotic-assisted technology was reviewed. Diagnoses, Cobb angles, surgical time, robot time, number of screws placed, and complications were recorded. Accuracy of screw placement was assessed based on analysis of successful screw execution, evaluation screw position using intraoperative fluoroscopy and post-operative radiographs, and clinical evaluation. The average age was 14.5 years. Prevalent diagnoses included idiopathic (65%) and neuromuscular scoliosis (13%). Mean preoperative curve measured 66.8°. The median time for operation was 235 minutes with medians of 8 levels fused and 5 screws placed per patient. Of the 314 screws placed, we recorded a 98.7% accuracy rate. Lateral deviation was the most common cause of malpositioning. Post-operative plain films revealed no grossly misplaced screws. There were no perioperative neurologic deficits or malpositioned screws requiring reoperation. This is the first reported series of navigated spinal robotics used for pedicle screw placement in children. Our clinical success rate was 98.7% and there were no clinically relevant screw related complications. The study shows promising initial results of combined robotic-navigation techniques in pediatric patients.

Transabdominal Motor Action Potential Monitoring of Pedicle Screw Placement During Minimally Invasive Spinal Procedures: A Case Study

Precise pedicle screw placement is a critical skill during minimally invasive spinal surgeries but can pose various challenges. Techniques such as electromyography (EMG) have been traditionally utilized for this purpose but have several shortcomings. Transabdominal motor action potential (TaMAP) has been examined as a possible effective neuromonitoring alternative and is hypothesized to provide important data on symptomatic malpositioned pedicle screws. The current study seeks to determine whether TaMAP may be an advantageous technique in the neuromonitoring of percutaneous pedicle screw placement during minimally invasive spinal procedures. The methodology involved recording TaMAP signals at the outset and the conclusion of spinal surgical procedures in human participants, for which comparisons were made of pre- and post-operative data. Results revealed that TaMAP signals remained stable during accurate pedicle screw placement and degraded during a case of inaccurate placement, for which initial misplaced hardware altered the depolarization threshold and resulted in substantial signal alteration. These results suggest that TaMAP, which is stable, repeatable, and reflects real-time information, can potentially be used as a reliable and more precise indication of accuracy in pedicle screw placement during spinal surgeries. This is the first TaMAP study conducted in human participants.

Robotic spine surgery: Ushering in a new era

The endeavour to make spine surgery safe with reproducible, consistent outcomes has led to growing interest and research in the field of intraoperative imaging, navigation and robotics. The advent of surgical robot systems in spine surgery is relatively recent - with only a few systems approved for commercial use. At present, pedicle screw insertion remains the primary application of robotic systems in spine surgery. The purported advantages of robot-assisted pedicle screw insertion over other conventional techniques are its increased accuracy, reproducible consistency and reduced radiation exposure. Many of these claims have been supported or refuted by individual studies - and high quality evidence for the same is lacking. Robotic spine surgery also has its share of limitations which include increased operative time, considerable learning curve and technical pitfalls unique to the robotic systems. The applications of robotic spine surgery are evolving and expanding to spinal deformity, spine oncology and needle-based interventional treatments. This review provides an overview of the evolution and current status of robotic spine surgery along with an evidence-based discussion of its current applications in spine surgery.