Step-by-step guide to robotic-guided minimally invasive transforaminal lumbar interbody fusion (MI-TLIF)

Impact of age on comparative outcomes of decompression alone versus fusion for L4 degenerative spondylolisthesis

PURPOSE

To compare the outcomes of decompression alone and fusion for L4-5 DLS in different age cohorts (< 70 years, ≥ 70 years).

METHODS

This retrospective cohort study included patients who underwent minimally invasive decompression or fusion for L4-5 DLS and had a minimum of 1-year follow-up. Outcome measures were: (1) patient-reported outcome measures (PROMs) (Oswestry Disability Index, ODI; Visual Analog Scale back and leg, VAS; 12-Item Short Form Survey Physical Component Score, SF-12 PCS), (2) minimal clinically important difference (MCID), (3) patient acceptable symptom state (PASS), (4) response on the global rating change (GRC) scale, and (5) complication rates. The decompression and fusion groups were compared for outcomes separately in the < 70-year and ≥ 70-year age cohorts.

RESULTS

233 patients were included, out of which 52% were < 70 years. Patients < 70 years showed non-significant improvement in SF-12 PCS and significantly lower MCID achievement rates for VAS back after decompression compared to fusion. Analysis of the ≥ 70-year age cohort showed no significant differences between the decompression and fusion groups in the improvement in PROMs, MCID/PASS achievement rates, and responses on GRC. Patients ≥ 70 years undergoing fusion had significantly higher in-hospital complication rates. When analyzed irrespective of the surgery type, both < 70-year and ≥ 70-year age cohorts showed significant improvement in PROMs with no significant difference.

CONCLUSIONS

Patients < 70 years undergoing decompression alone did not show significant improvement in physical function and had significantly less MCID achievement rate for back pain compared to fusion. Patients ≥ 70 years showed no difference in outcomes between decompression alone and fusion.

Effectiveness and safety of robot-assisted minimally invasive transforaminal lumbar interbody fusion for degenerative lumbar spinal diseases: a systematic review and meta-analysis

Robot-assisted (RA) technology has been widely used in spine surgery. This analysis aimed to compare the effectiveness and safety of RA minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) and fluoroscopy-assisted (FA) MIS-TLIF for degenerative lumbar spinal diseases (DLSD). PubMed, Web of Science, Cochrane Library, and China National Knowledge Infrastructure were systematically searched, and the outcomes included surgical parameters [operation time, blood loss, number of fluoroscopic, accuracy of pedicle screw position, superior facet joint violation (FJV)], and clinical indexes (Visual Analog Scale (VAS), Oswestry Disability Index (ODI), Japanese Orthopaedic Association (JOA) score, clinical efficacy, hospital stays, complications). Eleven articles involving 1066 patients were included. RA group produced better results than the FA group in operation time (WMD = - 6.59; 95% CI - 12.79 to - 0.40; P = 0.04), blood loss (WMD = - 34.81; 95% CI - 50.55 to - 19.08; P < 0.0001), number of fluoroscopic (WMD = - 18.24; 95% CI - 30.63 to - 5.85; P = 0.004), accuracy of pedicle screw position: Grade A (OR = 3.16; 95% CI 2.36-4.23; P < 0.00001), Grade B (OR = 0.39; 95% CI 0.28-0.54; P < 0.00001), Grade C (OR = 0.27; 95% CI 0.13-0.54; P = 0.0002), and Grade D (OR = 0.17; 95% CI 0.03-0.98; P = 0.05), FJV: Grade 0 (OR = 3.27; 95% CI 1.34-8.02; P = 0.010), Grade 1 (OR = 0.24; 95% CI 0.16-0.38; P < 0.00001), Grade 2 (OR = 0.24; 95% CI 0.12-0.51; P = 0.0002), and Grade 3 (OR = 0.26; 95% CI 0.07-0.93; P = 0.04). But no significant differences in VAS score, ODI, JOA score, clinical efficacy, hospital stays, and complications. These results demonstrate a significant improvement in the intraoperative course of the RA technique. However, RA-MIS-TLIF has not yet demonstrated significant advantages in terms of postoperative symptom relief and functional improvement. Future research and clinical practice should further explore the efficacy of this technique to optimize outcomes and quality of life for patients with DLSD. The study was registered in the PROSPERO (CRD42023454405).

Perception of Robotics and Navigation by Spine Fellows and Early Attendings: The Impact of These Technologies on Their Training and Practice

BACKGROUND

There is scant data on the role that robotics and navigation play in spine surgery training and practice of early attendings. This study aimed to assess the impact of navigation and robotics on spine surgery training and practice.

METHODS

A survey gathering information on utilization of navigation and robotics in training and practice was administered to trainees and early attendings.

RESULTS

A total of 51 surveys were returned completed: 71% were attendings (average practice years: 2), 29% were trainees. During training, 22% were exposed to only fluoroscopy, 75% were exposed to navigation, 51% were exposed to robotics, and 40% were exposed to both navigation and robotics. In our sample, 87% and 61% of respondents who had exposure to navigation and robotics, respectively, felt that it had a positive impact on their training. In practice, 28% utilized only fluoroscopy, 69% utilized navigation, 30% utilized robotics, and 28% utilized both navigation and robotics. The top 3 reasons behind positive impact on training and practice were: 1) increased screw accuracy, 2) exposure to upcoming technology, and 3) less radiation exposure. The top 3 reasons behind negative impact were: 1) compromises training to independently place screws, 2) time and personnel requirements, and 3) concerns about availing it in practice. In sum, 76% of attendings felt that they will be utilizing more navigation and robotics in 5 years' time.

CONCLUSIONS

Navigation and robotics have a perceivably positive impact on training and are increasingly being incorporated into practice. However, associated concerns demand spine surgeons to be thoughtful about how they integrate these technologies moving forward.

Predictors of Subsidence and its Clinical Impact After Expandable Cage Insertion in Minimally Invasive Transforaminal Interbody Fusion

STUDY DESIGN

Retrospective review of prospectively collected multisurgeon data.

OBJECTIVE

Examine the rate, clinical impact, and predictors of subsidence after expandable minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) cage.

SUMMARY OF BACKGROUND DATA

Expandable cage technology has been adopted in MI-TLIF to reduce the risks and optimize outcomes. Although subsidence is of particular concern when using expandable technology as the force required to expand the cage can weaken the endplates, its rates, predictors, and outcomes lack evidence.

MATERIALS AND METHODS

Patients who underwent 1 or 2-level MI-TLIF using expandable cages for degenerative lumbar conditions and had a follow-up of >1 year were included. Preoperative and immediate, early, and late postoperative radiographs were reviewed. Subsidence was determined if the average anterior/posterior disc height decreased by >25% compared with the immediate postoperative value. Patient-reported outcomes were collected and analyzed for differences at the early (<6 mo) and late (>6 mo) time points. Fusion was assessed by 1-year postoperative computed tomography.

RESULTS

One hundred forty-eight patients were included (mean age, 61 yr, 86% 1-level, 14% 2-level). Twenty-two (14.9%) demonstrated subsidence. Although statistically not significant, patients with subsidence were older, had lower bone mineral density, and had higher body mass index and comorbidity burden. Operative time was significantly higher ( P = 0.02) and implant width was lower ( P < 0.01) for subsided patients. Visual analog scale-leg was significantly lower for subsided patients compared with nonsubsided patients at a >6 months time point. Long-term (>6 mo) patient-acceptable symptom state achievement rate was lower for subsided patients (53% vs . 77%), although statistically not significant ( P = 0.065). No differences existed in complication, reoperation, or fusion rates.

CONCLUSIONS

Of the patients, 14.9% experienced subsidence predicted by narrower implants. Although subsidence did not have a significant impact on most patient-reported outcome measures and complication, reoperation, or fusion rates, patients had lower visual analog scale-leg and patient-acceptable symptom state achievement rates at the >6-month time point.

LEVEL OF EVIDENCE

Level 4.

Preoperative Disability Influences Effectiveness of MCID and PASS in Predicting Patient Improvement Following Lumbar Spine Surgery

STUDY DESIGN

Retrospective cohort.

SUMMARY OF BACKGROUND DATA

Although minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) are utilized to interpret Oswestry Disability Index (ODI), it is unclear whether there is a clearly better metric between the two and if not, which metric should be utilized when.

OBJECTIVE

To compare the characteristics of MCID and PASS when interpreting ODI after lumbar spine surgery.

METHODS

Patients who underwent primary minimally invasive transforaminal lumbar interbody fusion or decompression were included. The ODI and global rating change data at 1 year were analyzed. The global rating change was collapsed to a dichotomous outcome variable-(a) improved, (b) not improved The sensitivity, specificity, positive predictive value and negative predictive value of MCID and PASS were calculated for the overall cohort and separately for patients with minimal, moderate, and severe preoperative disability. Two groups with patients who achieved PASS but not MCID and patients who achieved MCID but not PASS were analyzed.

RESULTS

Two hundred twenty patients (mean age 62 y, 57% males) were included. PASS (86% vs. 69%) and MCID (88% vs. 63%) had significantly greater sensitivity in patients with moderate and severe preoperative disability, respectively. Nineteen percent of patients achieved PASS but not MCID and 10% of patients achieved MCID but not PASS, with the preoperative ODI being significantly greater in the latter. Most of these patients still reported improvement with no significant difference between the 2 groups (93% vs. 86%).

CONCLUSION

Significant postoperative clinical improvement is most effectively assessed by PASS in patients with minimal or moderate preoperative disability and by MCID in patients with severe preoperative disability. Adequate interpretation of ODI using the PASS and MCID metrics warrants individualized application as their utility is highly dependent on the degree of preoperative disability.

Floor-Mounted Robotic Pedicle Screw Placement in Lumbar Spine Surgery: An Analysis of 1,050 Screws

OBJECTIVE

To analyze the usage of floor-mounted robot in minimally invasive lumbar fusion.

METHODS

Patients who underwent minimally invasive lumbar fusion for degenerative pathology using floor-mounted robot (ExcelsiusGPS) were included. Pedicle screw accuracy, proximal level violation rate, pedicle screw size, screw-related complications, and robot abandonment rate were analyzed.

RESULTS

Two hundred twenty-nine patients were included. Most surgeries were primary single-level fusion. Sixty-five percent of surgeries had intraoperative computed tomography (CT) workflow, 35% had preoperative CT workflow. Sixty-six percent were transforaminal lumbar interbody fusion, 16% were lateral, 8% were anterior, and 10% were a combined approach. A total of 1,050 screws were placed with robotic assistance (85% in prone position, 15% in lateral position). Postoperative CT scan was available for 80 patients (419 screws). Overall pedicle screw accuracy rate was 96.4% (prone, 96.7%; lateral, 94.2%; primary, 96.7%; revision, 95.3%). Overall poor screw placement rate was 2.8% (prone, 2.7%; lateral, 3.8%; primary, 2.7%; revision, 3.5%). Overall proximal facet and endplate violation rates were 0.4% and 0.9%. Average diameter and length of pedicle screws were 7.1 mm and 47.7 mm. Screw revision had to be done for 1 screw (0.1%). Use of the robot had to be aborted in 2 cases (0.8%).

CONCLUSION

Usage of floor-mounted robotics for the placement of lumbar pedicle screws leads to excellent accuracy, large screw size, and negligible screw-related complications. It does so for screw placement in prone/lateral position and primary/revision surgery alike with negligible robot abandonment rates.