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

Utilization of Augmented Reality Head-Mounted Display for the Surgical Management of Thoracolumbar Spinal Trauma

Background and Objectives: Augmented reality head-mounted display (AR-HMD) is a novel technology that provides surgeons with a real-time CT-guided 3-dimensional recapitulation of a patient's spinal anatomy. In this case series, we explore the use of AR-HMD alongside more traditional robotic assistance in surgical spine trauma cases to determine their effect on operative costs and perioperative outcomes. Materials and Methods: We retrospectively reviewed trauma patients who underwent pedicle screw placement surgery guided by AR-HMD or robotic-assisted platforms at an academic tertiary care center between 1 January 2021 and 31 December 2022. Outcome distributions were compared using the Mann-Whitney U test. Results: The AR cohort (n = 9) had a mean age of 66 years, BMI of 29.4 kg/m2, Charlson Comorbidity Index (CCI) of 4.1, and Surgical Invasiveness Index (SII) of 8.8. In total, 77 pedicle screws were placed in this cohort. Intra-operatively, there was a mean blood loss of 378 mL, 0.78 units transfused, 398 min spent in the operating room, and a 20-day LOS. The robotic cohort (n = 13) had a mean age of 56 years, BMI of 27.1 kg/m2, CCI of 3.8, and SII of 14.2. In total, 128 pedicle screws were placed in this cohort. Intra-operatively, there was a mean blood loss of 432 mL, 0.46 units transfused units used, 331 min spent in the operating room, and a 10.4-day LOS. No significant difference was found between the two cohorts in any outcome metrics. Conclusions: Although the need to address urgent spinal conditions poses a significant challenge to the implementation of innovative technologies in spine surgery, this study represents an initial effort to show that AR-HMD can yield comparable outcomes to traditional robotic surgical techniques. Moreover, it highlights the potential for AR-HMD to be readily integrated into Level 1 trauma centers without requiring extensive modifications or adjustments.

The effect of pedicle screw instrumentation at a young age on upper thoracic vertebra and canal development

BACKGROUND CONTEXT

Pedicle screws are widely used in spinal surgeries. Pedicle screw fixation has shown better clinical effects than other techniques by providing steady fixation from the posterior arch to the vertebral body. However, there are several concerns about the impact of pedicle screw instrumentation insertion on vertebral development in young children, including early closure of the neurocentral cartilage (NCC). The effect of pedicle screw insertion in an early age on further growth of the upper thoracic spine is still unclear.

PURPOSE

This study aimed to evaluate the impact of pedicle screw insertion on further growth of the upper thoracic vertebra and spinal canal.

STUDY DESIGN

A retrospective case study.

PATIENT SAMPLE

Twenty-eight patients.

OUTCOME MEASUREMENTS

X-ray and CT parameters including length, height and area of the vertebrae and spinal canal were manually measured.

METHODS

Twenty-eight patients who underwent pedicle screw fixation (T1-T6) before the age of 5 years from March 2005 to August 2019 at Peking Union Medical College Hospital were recruited, and records were retrospectively reviewed. Vertebral body and spinal canal parameters were measured at instrumented and adjacent noninstrumented levels and compared using statistical methods.

RESULTS

Ninety-seven segments met the inclusion criteria (average age at instrumentation 44.57 months, range from 23-60 months). Thirty-nine segments had no screws, and 58 had at least one screw. There was no significant difference between the preoperative and final follow-up values of the measurement of vertebral body parameters. No significant difference was observed between the growth rates in levels with or without screws in pedicle length, vertebral body diameter, or spinal canal parameters.

CONCLUSION

Pedicle screw instrumentation in the upper thoracic spine does not cause a negative effect on the development of the vertebral body and spinal canal in children younger than 5 years old.

Navigated versus conventional pediatric spinal deformity surgery: Navigation independently predicts reoperation and infectious complications

Context

Literature on treating pediatric spinal deformity with navigation is limited, particularly using large nationally represented cohorts. Further, the comparison of single-institution data to national-level database outcomes is also lacking.

Aim

(1) To compare navigated versus conventional posterior pediatric deformity surgery based on 30-day outcomes and perioperative factors using the National Surgical Quality Improvement Program (NSQIP) database and (2) to compare the outcomes of the NSQIP navigated group to those of fluoroscopy-only and navigated cases from a single-institution.

Settings and Design

Retrospective cohort study.

Subjects and Methods

Pediatric patients who underwent posterior deformity surgery with and without navigation were included. Primary outcomes were 30-day readmission, reoperation, morbidity, and complications. The second part of this study included AIS patients < 18 years old at a single institution between 2015 and 2019. Operative time, length of stay, transfusion rate, and complication rate were compared between single-institution and NSQIP groups.

Statistical Analysis Used

Univariate analyses with independent t-test and Chi-square or Fisher's exact test was used. Multivariate analyses through the application of binary logistic regression models.

Results

Part I of the study included 16,950 patients, with navigation utilized in 356 patients (2.1%). In multivariate analysis, navigation predicted reoperation, deep wound infection, and sepsis. After controlling for operative year, navigation no longer predicted reoperation. In Part II of the study, 288 single institution AIS patients were matched to 326 navigation patients from the NSQIP database. Operative time and transfusion rate were significantly higher for the NSQIP group.

Conclusions

On a national scale, navigation predicted increased odds of reoperation and infectious-related events and yielded greater median relative value units (RVUs) per case but had longer operating room (OR) time and fewer RVUs-per-minute. After controlling for operative year, RVUs-per-minute and reoperation rates were similar between groups. The NSQIP navigated surgery group was associated with significantly higher operative time and transfusion rates compared to the single-institution groups.

Advances in robotics and pediatric spine surgery

PURPOSE OF REVIEW

Robotic-assisted surgical navigation for placement of pedicle screws is one of the most recent technological advancements in spine surgery. Excellent accuracy and reliability results have been documented in the adult population, but adoption of robotic surgical navigation is uncommon in pediatric spinal deformity surgery. Pediatric spinal anatomy and the specific pediatric pathologies present unique challenges to adoption of robotic assisted spinal deformity workflows. The purpose of this article is to review the safety, accuracy and learning curve data for pediatric robotic-assisted surgical navigation as well as to identify "best use" cases and technical tips.

RECENT FINDINGS

Robotic navigation has been demonstrated as a safe, accurate and reliable method to place pedicle screws in pediatric patients with a moderate learning curve. There are no prospective studies comparing robotically assisted pedicle screw placement with other techniques for screw placement, however several recent studies in the pediatric literature have demonstrated high accuracy and safety as well as high reliability. In addition to placement of pediatric pedicle screws in the thoracic and lumbar spine, successful and safe placement of screws in the pelvis and sacrum have also been reported with reported advantages over other techniques in the setting of high-grade spondylolisthesis as well as pelvic fixation utilizing S2-alar iliac (S2AI) screws.

SUMMARY

Early studies have demonstrated that robotically assisted surgical navigation for pedicle screws and pelvic fixation for S2AI screws is safe, accurate, and reliable in the pediatric population with a moderate learning curve.

Augmented reality in minimally invasive spine surgery: early efficiency and complications of percutaneous pedicle screw instrumentation

BACKGROUND CONTEXT

Augmented reality (AR) employs an optical projection directly onto the user's retina, allowing complex image overlay on the natural visual field. In general, pedicle screw accuracy rates have improved with increasingly use of technology, with navigation-based instrumentation described as accurate in 89%-100% of cases. Emerging AR technology in spine surgery builds upon current spinal navigation to provide 3-dimensional imaging of the spine and powerfully reduce the impact of inherent ergonomic and efficiency difficulties.

PURPOSE

This publication describes the first known series of in vivo pedicle screws placed percutaneously using AR technology for MIS applications.

STUDY DESIGN / SETTING

After IRB approval, 3 senior surgeons at 2 institutions contributed cases from June, 2020 - March, 2022. 164 total MIS cases in which AR used for placement of percutaneous pedicle screw instrumentation with spinal navigation were identified prospectively.

PATIENT SAMPLE

155 (94.5%) were performed for degenerative pathology, 6 (3.6%) for tumor and 3 (1.8%) for spinal deformity.  These cases amounted to a total of 606 pedicle screws; 590 (97.3%) were placed in the lumbar spine, with 16 (2.7%) thoracic screws placed.

OUTCOME MEASURES

Patient demographics and surgical metrics including total posterior construct time (defined as time elapsed from preincision instrument registration to final screw placement), clinical complications and instrumentation revision rates were recorded in a secure and de-identified database.

METHODS

The AR system used features a wireless headset with transparent near-eye display which projects intra-operative 3D imaging directly onto the surgeon's retina. After patient positioning, 1 percuntaneous and 1 superficial reference marker are placed. Intra-operative CT data is processed to the headset and integrates into the surgeon's visual field creating a "see-through" 3D effect in addition to 2D standard navigation images. MIS pedicle screw placement is then carried out percutaneously through single line of sight using navigated instruments.

RESULTS

Time elapsed from registration and percutaneous approach to final screw placement averaged 3 minutes and 54 seconds per screw.  Analysis of the learning curve revealed similar surgical times in the early cases compared to the cases performed with more experience with the system.  No instrumentation was revised for clinical or radiographic complication at final available follow-up ranging from 6-24 months. A total of 3 screws (0.49%) were replaced intra-operatively. No clinical effects via radiculopathy or neurologic deficit postoperatively were noted.

CONCLUSIONS

This is the first report of the use of AR for placement of spinal pedicle screws using minimally invasive techniques.   This series of 164 cases confirmed efficiency and safety of screw placement with the inherent advantages of AR technologies over legacy enabling technologies.