Complications Have Not Improved With Newer Generation Robots.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The purpose of this study was to see whether upgrades in newer generation robots improve safety and clinical outcomes following spine surgery. METHODS: All patients undergoing robotic-assisted spine surgery with the Mazor X Stealth EditionTM (Medtronic, Minneapolis, MN) from 2019 to 2022 at a combined orthopedic and neurosurgical spine service were retrospectively reviewed. Robot related complications were recorded. RESULTS: 264 consecutive patients (54.1% female; age at time of surgery 63.5 ± 15.3 years) operated on by 14 surgeons were analyzed. The average number of instrumented levels with robotics was 4.2 ± 2.7, while the average number of instrumented screws with robotics was 8.3 ± 5.3. There was a nearly 50/50 split between an open and minimally invasive approach. Six patients (2.2%) had robot related complications. Three patients had temporary nerve root injuries from misplaced screws that required reoperation, one patient had a permanent motor deficit from the tap damaging the L1 and L2 nerve roots, one patient had a durotomy from a misplaced screw that required laminectomy and intra-operative repair, and one patient had a temporary sensory L5 nerve root injury from a drill. Half of these complications (3/6) were due to a reference frame error. In total, four patients (1.5%) required reoperation to fix 10 misplaced screws. CONCLUSION: Despite newer generation robots, robot related complications are not decreasing. As half the robot related complications result from reference frame errors, this is an opportunity for improvement.

Novel use of robotics and navigation for anterior lumbar total disc replacement surgery.

The ability to navigate the anterior lumbar disc space may improve clinical outcomes and implant longevity. However, no robotic navigation systems are presently authorized by the U.S. Food and Drug Administration to assist with anterior retroperitoneal lumbar interbody surgery. Furthermore, no studies to date have investigated such an application of this technology. This study examines the application of robotic navigation to anterior lumbar total disc replacement surgery to improve retroperitoneal exposure and orientation of the anterior lumbar spine, enhance coronal plane centralization of the implant, optimize surgical trajectory, and mitigate radiologic exposure. Postoperative outcomes of a small cohort of patients undergoing anterior lumbar total disc replacement surgery using robotic navigation were analyzed. The results of the study revealed that a modified use of the aforementioned robot-assisted surgical technology enhances coronal plane centralization and trajectory, all while mitigating radiologic exposure, resulting in more accurate placement of the implant within the intervertebral space at each level.

Biomechanical Analysis of Cortical Versus Pedicle Screw Fixation Stability in TLIF, PLIF, and XLIF Applications.

STUDY DESIGN: Cadaveric biomechanical study. OBJECTIVES: Medial-to-lateral trajectory cortical screws are of clinical interest due to the ability to place them through a less disruptive, medialized exposure compared with conventional pedicle screws. In this study, cortical and pedicle screw trajectory stability was investigated in single-level transforaminal lumbar interbody fusion (TLIF), posterior lumbar interbody fusion (PLIF), and extreme lateral interbody fusion (XLIF) constructs. METHODS: Eight lumbar spinal units were used for each interbody/screw trajectory combination. The following constructs were tested: TLIF + unilateral facetectomy (UF) + bilateral pedicle screws (BPS), TLIF + UF + bilateral cortical screws (BCS), PLIF + medial facetectomy (MF) + BPS, PLIF + bilateral facetectomy (BF) + BPS, PLIF + MF + BCS, PLIF + BF + BCS, XLIF + BPS, XLIF + BCS, and XLIF + bilateral laminotomy + BCS. Range of motion (ROM) in flexion-extension, lateral bending, and axial rotation was assessed using pure moments. RESULTS: All instrumented constructs were significantly more rigid than intact (P < .05) in all test directions except TLIF + UF + BCS, PLIF + MF + BCS, and PLIF + BF + BCS in axial rotation. In general, XLIF and PLIF + MF constructs were more rigid (lowest ROM) than TLIF + UF and PLIF + BF constructs. In the presence of substantial iatrogenic destabilization (TLIF + UF and PLIF + BF), cortical screw constructs tended to be less rigid (higher ROM) than the same pedicle screw constructs in lateral bending and axial rotation; however, no statistically significant differences were found when comparing pedicle and cortical fixation for the same interbody procedures. CONCLUSIONS: Both cortical and pedicle trajectory screw fixation provided stability to the 1-level interbody constructs. Constructs with the least iatrogenic destabilization were most rigid. The more destabilized constructs showed less lateral bending and axial rotation rigidity with cortical screws compared with pedicle screws. Further investigation is warranted to understand the clinical implications of differences between constructs.

Longitudinal Pilot Analysis of Radiation Exposure During the Course of Growing Rod Treatment for Early-Onset Scoliosis.

STUDY DESIGN: Retrospective consecutive case series. OBJECTIVES: To estimate the amount of ionizing radiation (IR) exposure in growing rod (GR) surgery for early-onset scoliosis. SUMMARY OF BACKGROUND DATA: There is substantial evidence of the health hazards attributed to IR exposure. However, no studies have estimated the amount of IR exposure in GR surgery. MATERIALS AND METHODS: A consecutive single-center series of GR patients were retrospectively reviewed. Of 28 total patients, 24 had a minimum 2-year follow-up and complete records available for analysis. All spine-related IR imaging studies excluding intraoperative fluoroscopy were tabulated and IR estimated based on historical controls in millisieverts (mSv). RESULTS: Initial x-ray evaluation for scoliosis was performed at a mean age of 4.0 years (range = birth to 9.7). Mean radiographic period was 8.5 years (range = 2.2 to 19.4). There was a statistically significant inverse correlation between patient age at time of initial IR and total mean IR (p < .05). Total IR was 3.4 times greater than that of estimated background radiation (2.4 mSv per year). Mean IR before index surgery and during the first postoperative year were 22.41 mSv and 10.78 mSv, respectively. Annual IR after the first postoperative year averaged 7.02 mSv (range = 2.25 to 13.45). Patients who underwent at least one revision surgery experienced significantly higher IR than nonrevision patients (79.95 vs. 46.58 mSv; p < .05). Overall, 89% of total IR was attributed to x-rays and 11% from computed tomography. CONCLUSIONS: Compared to the general public, GR patients had 3.4 times more IR than the estimated background radiation for the same duration of time. Younger patients and those requiring revision surgery had significantly higher IR doses. This study underscores the importance of recognizing the amount of IR used in the management of GR patients and its potential long-term risks. LEVEL OF EVIDENCE: III.