Rate and Risk Factors of Superior Facet Joint Violation during Cortical Bone Trajectory Screw Placement: A Comparison of Robot-Assisted Approach with a Conventional Technique

Comparison of rostral facet joint violations in robotic- and navigation-assisted pedicle screw placement for adult lumbar spine instrumentation

BACKGROUND CONTEXT

Facet joint violation by pedicle screws may lead to adjacent-segment disease and postoperative pain. Previous studies have reported the incidence of rostral facet joint violation using various pedicle screw insertion techniques. However, the incidence of facet joint violations with robotic guidance has not been determined.

PURPOSE

To investigate and compare the incidence of rostral facet joint violation by pedicle screws under robotic guidance and computerized tomography (CT) navigation guidance.

STUDY DESIGN/SETTING

Retrospective matched cohort.

PATIENT SAMPLE

All patients who underwent robotic-assisted lumbar fusion at a major spine center up until 2023 were retrospectively identified and matched 1:3 to patients undergoing CT navigation guidance based by on age, sex, rostral vertebral level, and length of construct. Inclusion criteria consisted of age greater than 18 years, bilateral pedicle screw fixation, and presence of a postoperative CT scan of the lumbar spine or abdomen/pelvis at any point in the post-operative period.

OUTCOME MEASURES

Rostral facet joint violations.

METHODS

Descriptive statistics were used to compare cohorts: frequencies, chi-squared analysis for categorical variables, and t-test for continuous variables.

RESULTS

A total of 408 rostral pedicle screws were implanted in 204 patients (Robot: 102; Navigation: 306). Overall, 13 (12.3%) rostral facet joint violations were observed in the robot cohort and 75 (24.5%) in the navigation cohort (p=.01). Specifically, fewer robotic violations were observed at the L2 (3.5% vs. 32.1%, p=.003) and L3 levels (3.9% vs. 18.1%, p=.08) compared to navigation. No difference was observed at L4 and L5. Bilateral violations are significantly reduced with robotic approaches (5.3% vs. 14.4%, p=.03). Lastly, more facet joint violations were observed during open approaches (robot: 18.8%, navigation: 27.3%) than percutaneous approaches (robot: 11.6%, navigation: 7.1%) in both groups (p<.001). The rate of L4 facet violations was 18.8% in the robotic cohort and 27.3% in the navigation cohort. The rate of L5 facet violations was 31.3% in the robotic cohort and 29.2% in the navigation cohort.

CONCLUSIONS

Use of robotic assistance in lumbar pedicle screws significantly reduced the rate of rostral facet joint violations compared to navigation guidance at L2 and L3 levels, but not at L4 and L5, with facet violations approaching nearly one-third of the patients at L5 screws. Rostral facet violations can play a significant role in adjacent segment degeneration and disease. Technical factors and trajectory issues likely play a role and addressing these components should minimize unintended facet violation and proximal adding on.

Risk Factors for Medial Breach During Robotic-Assisted Cortical Bone Trajectory Screw Insertion

OBJECTIVE

We describe the incidence of, and identify the risk factors for, a medial breach of the pedicle wall during robotic-assisted cortical bone trajectory (RA-CBT) screw insertion.

METHODS

We analyzed a consecutive series of adult patients who underwent RA-CBT screw placement from January 2019 to July 2022. To assess the pedicle wall medial breach, postoperative computed tomography (CT) images were analyzed. Patient demographic data and screw data were compared between patients with and without a medial breach. The Hounsfield units (HUs) on the L1 midvertebral axial CT scan was used to evaluate bone quality.

RESULTS

Of 784 CBT screws in 145 patients, 30 (3.8%) had a medial breach in 23 patients (15.9%). One screw was grade 2, and the others were grade 1. Patients with a medial breach had a lower HU value compared with the patients without a medial breach (123.3 vs. 150.5; P = 0.027). A medial breach was more common in the right than left side (5.5% vs. 2.0%; P = 0.014). More than one half of the screws with a medial breach were found in the upper instrumented vertebra (UIV) compared with the middle construct or lowest instrumented vertebra (6.7% vs. 1.3% vs. 2.7%; P = 0.003). Binary logistic regression showed that low HU values, right-sided screw placement, and UIV were associated with a medial breach. No patients returned to the operating room for screw malposition. No differences were found in the clinical outcomes between patients with and without a medial breach.

CONCLUSIONS

The incidence of pedicle wall medial breach was 3.8% of RA-CBT screws in the postoperative CT images. A low HU value measured in the L1 axial image, right-sided screw placement, and UIV were associated with an increased risk of medial breach for RA-CBT screw placement.

Effectiveness and safety of robot-assisted versus fluoroscopy-assisted cortical bone trajectory screw instrumentation in spinal surgery: a systematic review and meta-analysis

Robot-assisted (RA) technology has been shown to be a safe aid in spine surgery, this meta-analysis aims to compare surgical parameters and clinical indexes between robot-assisted cortical bone trajectory (CBT) and fluoroscopy-assisted (FA) cortical bone trajectory in spinal surgery. We searched databases such as PubMed, Web of Science, the Cochrane Library, and the China National Knowledge Infrastructure. The study selection process was guided by the PICOS (Patient/Problem, Intervention, Comparison, Outcome, Study Design) strategy. The risk of bias in non-randomized comparative studies was assessed using the risk of bias in non-randomized studies of interventions (ROBINS-I) tool. We performed this meta-analysis using RevMan 5.3 software (Cochrane Collaboration, Copenhagen, Denmark), and the level of statistical significance was set at P < 0.05. Six articles involving 371 patients and 1535 screws were included in this meta-analysis. RA-CBT outperformed FA-CBT in terms of various parameters, such as accuracy of pedicle screw position (both Gertzbein-Robbins scale and Ding scale), avoidance of superior facet joint violation (FJV), and reduction of neurological injury. Our meta-analysis offered a thorough evaluation of the efficacy and safety of RA-CBT in spinal surgery. The findings revealed that RA-CBT produced statistically significant results in terms of pedicle screw position accuracy and superior facet joint violation prevention. In terms of surgical parameters and clinical indexes, future research and clinical practice should investigate the efficacy of RA-CBT further. The study was registered in the PROSPERO (CRD42023466280).

Trends in usage of navigation and robotic assistance in elective spine surgeries: a study of 105,212 cases from 2007 to 2015

OBJECTIVE

Identify trends of navigation and robotic-assisted elective spine surgeries.

METHODS

Elective spine surgery patients between 2007 and 2015 in the Nationwide Inpatient Sample (NIS) were isolated by ICD-9 codes for Navigation [Nav] or Robotic [Rob]-Assisted surgery. Basic demographics and surgical variables were identified via chi-squared and t tests. Each system was analyzed from 2007 to 2015 for trends in usage.

RESULTS

Included 3,759,751 patients: 100,488 Nav; 4724 Rob. Nav were younger (56.7 vs 62.7 years), had lower comorbidity index (1.8 vs 6.2, all p < 0.05), more decompressions (79.5 vs 42.6%) and more fusions (60.3 vs 52.6%) than Rob. From 2007 to 2015, incidence of complication increased for Nav (from 5.8 to 21.7%) and Rob (from 3.3 to 18.4%) as well as 2-3 level fusions (from 50.4 to 52.5%) and (from 1.3 to 3.2%); respectively. Invasiveness increased for both (Rob: from 1.7 to 2.2; Nav: from 3.7 to 4.6). Posterior approaches (from 27.4 to 41.3%), osteotomies (from 4 to 7%), and fusions (from 40.9 to 54.2%) increased in Rob. Anterior approach for Rob decreased from 14.9 to 14.4%. Nav increased posterior (from 51.5% to 63.9%) and anterior approaches (from 16.4 to 19.2%) with an increase in osteotomies (from 2.1 to 2.7%) and decreased decompressions (from 73.6 to 63.2%).

CONCLUSIONS

From 2007 to 2015, robotic and navigation systems have been performed on increasingly invasive spine procedures. Robotic systems have shifted from anterior to posterior approaches, whereas navigation computer-assisted procedures have decreased in rates of usage for decompression procedures.

Accuracy and Screw Insertion Time of Robotic-Assisted Cortical Bone Trajectory Screw Placement for Posterior Lumbar Interbody Fusion: A Comparison of Early, Middle, and Late Phases

Introduction The purpose of this study was to evaluate robotic-assisted cortical bone trajectory (CBT) screw placement. Early, middle, and late phases of robotic-assisted CBT screw placement were compared for accuracy and screw insertion time by comparing time and accuracy in every phase.  Methods A retrospective review was conducted on the initial 40 patients who underwent spinal fusion using CBT screws in one institution from September 2021 to September 2022 utilizing a spine surgery robot system (Mazor X Stealth Edition, Medtronic Inc., Dublin, Ireland). The inclusion criterion was one- or two-level posterior lumbar interbody fusion (PLIF). Exclusion criteria were 1) patients who underwent posterior-lateral fusion in other segments, 2) patients who underwent additional decompression in other segments, 3) patients who underwent reoperation, and 4) patients with spondylolysis. The deviation of the CBT screw was evaluated on computed tomography (CT) one week after surgery using the Gertzbein-Robbins grade system. The rate of Grade A was considered the perfect accuracy rate, and the rate of penetration of 2 mm or more (Grades C, D, and E) was calculated as the deviation rate. To assess the learning curve, patients were divided into three groups. The first 10 cases were in the early phase group, the subsequent 10 cases were in the middle phase group, and the last 10 cases were in the late phase group. We compared the perfect accuracy rate, deviation rate, operative time, operative time per segment, intraoperative blood loss, registration time, and screw insertion time among the three groups. Results Thirty patients met the criteria. Overall, the perfect accuracy (Grade A) rate of the screw was 95.3% and the deviation rate was 1.4%. The perfect accuracy rate was 90.4% in the early phase, 95.5% in the middle phase, and 100% in the late phase. The deviation rate was 3.8% in the early phase, 0% in the middle phase, and 0% in the late phase, and there was no statistically significant difference between the three groups. Among the three groups, the operative time, the operative time per segment, the intraoperative blood loss, and the registration time were not significantly different. There was no significant difference in the screw insertion time among the three groups, but it decreased with experience (early phase: 156.9 ± 54.7 sec, middle phase: 139.9 ± 41.6 sec, and late phase: 106.4 ± 39.9 sec, p=0.060). The screw insertion time of the late phase tended to be shorter than that of the early phase (p=0.052). Conclusions The deviation rate of robotic-assisted CBT screw placement with one- or two-level PLIF was 1.4%, which was highly accurate. The deviation rate was 3.8% in the early phase, 0% in the middle phase, and 0% in the late phase. Although the deviation rate was low even in the early period, the screw insertion time in the early 10 cases tended to be longer than that in the late 10 cases. After passing the experience of 10 cases, this study concluded that robotic-assisted CBT screw placement was proficient.

Safety and risk factors of TINAVI robot-assisted percutaneous pedicle screw placement in spinal surgery

Objective

To determine the rates and risk factors of pedicle screw placement accuracy and the proximal facet joint violation (FJV) using TINAVI robot-assisted technique.

Methods

Patients with thoracolumbar fractures or degenerative diseases were retrospectively recruited from June 2018 and June 2020. The pedicle penetration and proximal FJV were compared in different instrumental levels to identify the safe and risk segments during insertion. Moreover, the factors were also assessed using univariate and multivariate analyses.

Results

A total of 72 patients with 332 pedicle screws were included in the current study. The optimal and clinically acceptable screw positions were 85.8% and 93.4%. Of the 332 screws concerning the intra-pedicular accuracy, 285 screws (85.8%) were evaluated as Grade A according to the Gertzbein and Robbins scale, with the remaining 25 (7.6%), 10 (3.0%), 6 (1.8%), and 6 screws (1.8%) as Grades B, C, D, and E. Moreover, in terms of the proximal FJV, 255 screws (76.8%) screws were assessed as Grade 0 according to the Babu scale, with the remaining 34 (10.3%), 22 (6.6%), and 21 screws (6.3%) as Grades 1, 2, and 3. Furthermore, the univariate analysis showed significantly higher rate of penetration for patients with age < 61 years old, sex of female, thoracolumbar insertion, shorter distance from skin to insertion point, and smaller facet angle. Meanwhile, the patients with the sex of female, BMI < 25.9, grade I spondylolisthesis, lumbosacral insertion, longer distance from skin to insertion point, and larger facet angle had a significantly higher rate of proximal FJV. The outcomes of multivariate analyses showed that sex of male (adjusted OR 0.320, 95% CI 0.140–0.732; p = 0.007), facet angle ≥ 45° (adjusted OR 0.266, 95% CI 0.090–0.786; p = 0.017), distance from skin to insertion point ≥ 4.5 cm (adjusted OR 0.342, 95% CI 0.134–0.868; p = 0.024), and lumbosacral instrumentation (adjusted OR 0.227, 95% CI 0.091–0.566; p = 0.001) were independently associated with intra-pedicular accuracy; the L5 insertion (adjusted OR 2.020, 95% CI 1.084–3.766; p = 0.027) and facet angle ≥ 45° (adjusted OR 1.839, 95% CI 1.026–3.298; p = 0.041) were independently associated with the proximal FJV.

Conclusion

TINAVI robot-assisted technique was associated with a high rate of pedicle screw placement and a low rate of proximal FJV. This new technique showed a safe and precise performance for pedicle screw placement in spinal surgery. Facet angle ≥ 45° is independently associated with both the intra-pedicular accuracy and proximal FJV.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-022-03271-6.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Rates and risk factors of intrapedicular accuracy and cranial facet joint violation among robot-assisted, fluoroscopy-guided percutaneous, and freehand techniques in pedicle screw fixation of thoracolumbar fractures: a comparative cohort study

Background

Robot-assisted (RA) technique has been increasingly applied in clinical practice, providing promising outcomes of inserting accuracy and cranial facet joint protection. However, studies comparing this novel method with other assisted methods are rare, and the controversy of the superiority between the insertion techniques remains. Thus, we compare the rates and risk factors of intrapedicular accuracy and cranial facet joint violation (FJV) of RA, fluoroscopy-guided percutaneous (FP), and freehand (FH) techniques in the treatment of thoracolumbar fractures.

Methods

A total of 74 patients with thoracolumbar fractures requiring pedicle screw instruments were retrospectively included and divided into RA, FP, and FH groups from June 2016 to May 2020. The primary outcomes were the intrapedicular accuracy and cranial FJV. The factors that affected the intrapedicular accuracy and cranial FJV were assessed using multivariate analyses.

Results

The optimal intrapedicular accuracy of pedicle screw placement (Grade A) in the RA, FP, and FH groups was 94.3%, 78.2%, and 88.7%, respectively. This finding indicates no significant differences of RA over FH technique (P = 0.062) and FP technique (P = 0.025), but significantly higher accuracies of RA over FP (P < 0.001). In addition, the rates of proximal FJV in RA, FP, and FH groups were 13.9%, 30.8%, and 22.7%, respectively. RA had a significantly greater proportion of intact facet joints than the FP (P = 0.002). However, FP and FH (P = 0.157), as well as RA and FH (P = 0.035) showed significantly similar outcomes with respect to the proximal FJV. The logistic regression analysis showed that FP technique (OR = 3.056) was independently associated with insertion accuracy. Meanwhile, the age (OR = 0.974), pedicle angle (OR = 0.921), moderate facet joint osteoarthritis (OR = 5.584), and severe facet joint osteoarthritis (OR = 11.956) were independently associated with cranial FJV.

Conclusion

RA technique showed a higher rate of intrapedicular accuracy and a lower rate of cranial FJV than FP technique, and similar outcomes to FH technique in terms of intrapedicular accuracy and cranial FJV. RA technique might be a safe method for pedicle screw placement in thoracolumbar surgery.

Level of evidence

3

Historical Note: The Evolution of Cortical Bone Trajectory and Associated Techniques

Cortical bone trajectory (CBT) for posterior fixation with pedicle screws is considered a relatively new alternative trajectory that travels in the medio-lateral direction in the transverse plane and in the caudo-cephalad path in the sagittal plane. Various biomechanical studies have already validated its superior pullout strength and mechanical stability over the traditional trajectory of convergent pedicle screws. Due to the relatively medial starting point of this trajectory, the CBT also poses the clinical advantage of requiring a smaller surgical field of exposure, thus minimizing tissue and muscle injury while reducing operative time and intraoperative blood loss. The evolution of CBT through time has closely been linked to the unwavering philosophy of prioritizing patient outcomes, advancements in neuronavigational technology, and the mounting biomechanical, morphometric, and clinical evidence. In this historical review, we provide a unique perspective on how CBT surgical technique has developed through time, highlighting key milestones and attempting to explain its explosive rise in popularity.

The Rates and Risk Factors of Intra-Pedicular Accuracy and Proximal Facet Joint Violation for Single-Level Degenerative Lumbar Diseases: Cortical Bone Trajectory Versus Traditional Trajectory Pedicle Screw

STUDY DESIGN

A retrospective study.

OBJECTIVE

To compare the accuracy of pedicle screw placement and proximal facet joint violation (FJV) in single-level degenerative lumbar diseases using cortical bone trajectory (CBT) and traditional trajectory (TT) techniques, and analyze their possible risk factors.

SUMMARY OF BACKGROUND DATA

CBT screws have been utilized increasingly to improve cortical bone contact to prevent screw pullout and reduce approach-related morbidity. However, the studies on intra-pedicular accuracy and proximal FJV between the two methods are rare.

METHODS

A total of 40 patients who required single-level instruments were included in the retrospective study treated with the CBT-TLIF and the TT-TLIF at a 1:1 ratio from March 2019 to August 2020. The radiographic outcomes were the intra-pedicular accuracy and proximal FJV. Moreover, the possible risk factors were assessed using bivariate and multivariate analyses.

RESULTS

As for the intra-pedicular accuracy, 73 screws (91.3%) were classified as grade A, 7 screws (8.7%) classified as grade B in the CBT group. A total of 71 screws (88.8%) were graded A with remaining 8 screws (10.0%) graded B and 1 screw (1.2%) graded C in the TT group. The proportion of optimal and clinically acceptable screw positions in the two groups were not significantly different (P > 0.05). In addition, the rate of proximal FJV in CBT approach (8.3%) was significantly lower than that in the TT approach (35.0%) (P < 0.001). Multivariate analysis showed the TT insertion approach and facet angle ≥45° were the independent risk factors for proximal FJV, but no factors above affected intra-pedicular accuracy.

CONCLUSION

Compared with the TT approach in TLIF, the CBT approach showed similar intra-pedicular accuracy and remarkable superiority in proximal facet joint protection. Facet angle ≥45° is the independent risk factors for proximal FJV.Level of Evidence: 2.

Emerging Technologies in the Treatment of Adult Spinal Deformity

Outcomes for adult spinal deformity continue to improve as new technologies become integrated into clinical practice. Machine learning, robot-guided spinal surgery, and patient-specific rods are tools that are being used to improve preoperative planning and patient satisfaction. Machine learning can be used to predict complications, readmissions, and generate postoperative radiographs which can be shown to patients to guide discussions about surgery. Robot-guided spinal surgery is a rapidly growing field showing signs of greater accuracy in screw placement during surgery. Patient-specific rods offer improved outcomes through higher correction rates and decreased rates of rod breakage while decreasing operative time. The objective of this review is to evaluate trends in the literature about machine learning, robot-guided spinal surgery, and patient-specific rods in the treatment of adult spinal deformity.

The Clinical Impact of Image Guidance and Robotics in Spinal Surgery: A Review of Safety, Accuracy, Efficiency, and Complication Reduction

Image guidance (IG) and robotic-assisted (RA) surgery are modern technological advancements that have provided novel ways to perform precise and accurate spinal surgery. These innovations supply real-time, three-dimensional imaging information to aid in instrumentation, decompression, and implant placement. Although nothing can replace the knowledge and expertise of an experienced spine surgeon, these platforms do have the potential to supplement the individual surgeon's capabilities. Specific advantages include more precise pedicle screw placement, minimally invasive surgery with less reliance on intraoperative fluoroscopy, and lower radiation exposure to the surgeon and staff. As these technologies have become more widely adopted over the years, novel uses such as tumor resection have been explored. Disadvantages include the cost of implementing IG and robotics platforms, the initial learning curve for both the surgeon and the staff, and increased patient radiation exposure in scoliosis surgery. Also, given the relatively recent transition of many procedures from inpatient settings to ambulatory surgery centers, access to current devices may be cost prohibitive and not as readily available at some centers. Regarding patient-related outcomes, much further research is warranted. The short-term benefits of minimally invasive surgery often bolster the perioperative and early postoperative outcomes in many retrospective studies on IG and RA surgery. Randomized controlled trials limiting such confounding factors are warranted to definitively show potential independent improvements in patient-related outcomes specifically attributable to IG and RA alone. Nonetheless, irrespective of these current unknowns, it is clear that these technologies have changed the field and the practice of spine surgery. Surgeons should be familiar with the potential benefits and tradeoffs of these platforms when considering adopting IG and robotics in their practices.

Comparison of Cranial Facet Joint Violation Rate and Four Other Clinical Indexes Between Robot-assisted and Freehand Pedicle Screw Placement in Spine Surgery: A Meta-analysis

STUDY DESIGN

A meta-analysis.

OBJECTIVE

Through meta-analysis, whether RA techniques are superior to conventional freehand (FH) techniques was determined in terms of cranial facet joint protection and four other clinical indexes, namely, the accuracy of pedicle screw placement, the number of surgical revision due to malposition, intraoperative radiation dose, and operative time.

SUMMARY OF BACKGROUND DATA

Cranial facet joint violation (FJV) is an important risk factor for adjacent segment degeneration. Some studies recommended the use of robot-assisted (RA) pedicle screw placement in reducing the rate of cranial FJV instead of conventional FH pedicle screw placement. However, the superiority of RA techniques to FH techniques remains controversial.

METHODS

A comprehensive search on PubMed, EMBASE, Cochrane, Web of Science, CNKI, and WanFang was conducted for the selection of potential eligible literature. The outcomes were evaluated in terms of odds ratio (OR) or standardized mean difference and corresponding 95% confidence interval (CI). The meta-analysis was conducted using RevMan 5.3. The subgroup analyses of the violation of the cranial facet joint and the accuracy of pedicle screw placement were performed on the basis of robot type.

RESULT

Three randomized controlled trials, two prospective cohort study, and one retrospective cohort study consisting of 783 patients and 2694 cranial pedicle screws were included in the meta-analysis. RA pedicle screw placement was associated with significantly fewer cranial FJVs than FH screw placement. Subgroup analyses showed that the Renaissance (OR = 0.19, 95% CI = 0.07-0.56) and TINAVI (OR = 0.19, 95% CI = 0.09-0.38) robots under RA techniques were associated with significantly fewer cranial FJVs than FH techniques. Furthermore, the RA techniques showed more accurate pedicle screw placement and lower intraoperative radiation dose, equivalent number of surgical revision due to malposition, but longer operative time than the FH techniques.

CONCLUSION

The RA (Renaissance and TINAVI) techniques are superior to conventional FH techniques in terms of protecting the cranial facet joint. RA techniques are accurate and safe in clinical application.

LEVEL OF EVIDENCE

2.

The impact of robot-assisted spine surgeries on clinical outcomes: A systemic review and meta-analysis

BACKGROUND

Medical robotics has enabled a significant advancement in the field of modern spine surgery, especially in pedicle screw fixation. A plethora of studies focused on the accuracy of pedicle fixation in robotic-assisted (RA) technology. However, it is not clear whether RA techniques can improve patients' clinical outcomes.

METHODS

We retrieved relevant studies that compare the differences between RA and freehand (FH) techniques in spine surgeries from the following databases: PubMed, Embase, Cochrane Library and Web of Science. The perioperative outcomes of this technology were measured with parameters including radiation exposure, operative time, the length of hospital stay, complication rates and revision rates. Two reviewers independently reviewed the studies in our sample, assessed their validity and extracted relevant data.

RESULTS

Our search resulted in a sample of 23 eligible studies, which involved 1247 patients (5042 pedicle screws) in the RA group and 1273 patients (4830 pedicle screws) in the FH group. With regard to the radiation exposure, the fluoroscopy time was less in surgeries assisted by Mazor robots (standard mean difference [SMD] = -0.96, 95% CI = -1.60 to -0.31) but more in Tianji robots (SMD = 0.91, 95% CI = 0.17 to 1.66) and ROSA robots (SMD = 2.57, 95% CI = 2.01 to 3.13). For radiation dose, a decrease was observed in Tianji robots (SMD = -1.59, 95% CI = -2.13 to -1.05). In the lumbar subgroup, the use of robots increased the operative time (SMD = 0.53, 95% CI = 0.19 to 0.86). In the degenerative diseases (DG) group, there was a significant decrease in the length of hospital stay when robots were introduced (SMD = -0.30, 95% CI = -0.48 to -0.12). While in the DF (deformity) and DG group, a significant increase was found (SMD = 0.17, 95% CI = 0.02 to 0.32). The complication (OR = 0.41, 95% CI = 0.26 to 0.66) and the revision rates (OR = 0.38, 95% CI = 0.24 to 0.60) showed a significant decrease in the RA group compared to the conventional FH group.

CONCLUSIONS

This study suggests that RA spine surgeries would result in fewer complications, a lower revision rate and shorter length of hospital stay. As the technology continues to evolve, we may expect more applications of robotic systems in spine surgeries.

Accuracy study of a binocular-stereo-vision-based navigation robot for minimally invasive interventional procedures

BACKGROUND

Medical robot is a promising surgical tool, but no specific one has been designed for interventional treatment of chronic pain. We developed a computed tomography-image based navigation robot using a new registration method with binocular vision. This kind of robot is appropriate for minimal invasive interventional procedures and easy to operate. The feasibility, accuracy and stability of this new robot need to be tested.

AIM

To assess quantitatively the feasibility, accuracy and stability of the binocular-stereo-vision-based navigation robot for minimally invasive interventional procedures.

METHODS

A box model was designed for assessing the accuracy for targets at different distances. Nine (three sets) lead spheres were embedded in the model as puncture goals. The entry-to-target distances were set 50 mm (short-distance), 100 mm (medium-distance) and 150 mm (long-distance). Puncture procedure was repeated three times for each goal. The Euclidian error of each puncture was calculated and statistically analyzed. Three head phantoms were used to explore the clinical feasibility and stability. Three independent operators conducted foramen ovale placement on head phantoms (both sides) by freehand or under the guidance of robot (18 punctures with each method). The operation time, adjustment time and one-time success rate were recorded, and the two guidance methods were compared.

RESULTS

On the box model, the mean puncture errors of navigation robot were 1.7 ± 0.9 mm for the short-distance target, 2.4 ± 1.0 mm for the moderate target and 4.4 ± 1.4 mm for the long-distance target. On the head phantom, no obvious differences in operation time and adjustment time were found among the three performers (P > 0.05). The median adjustment time was significantly less under the guidance of the robot than under free hand. The one-time success rate was significantly higher with the robot (P < 0.05). There was no obvious difference in operation time between the two methods (P > 0.05).

CONCLUSION

In the laboratory environment, accuracy of binocular-stereo-vision-based navigation robot is acceptable for target at 100 mm depth or less. Compared with freehand, foramen ovale placement accuracy can be improved with robot guidance.