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.

Outpatient Versus Inpatient Anterior Lumbar Spine Surgery: A Multisite, Comparative Analysis of Patient Safety Measures.

BACKGROUND: The frequency and complexity of spinal surgery performed in an ambulatory surgery center (ASC) is increasing. However, safety and efficacy data of most spinal procedures adapted to the ASC are sparse and have focused on anterior cervical surgery. The purpose of this study was to compare the 90-day complication and readmission rates of anterior lumbar spine surgery performed in an ASC or inpatient setting. METHODS: We performed a retrospective comparative analysis of 226 consecutive anterior lumbar surgeries (283 levels treated) completed in an ASC (n = 124) or in an inpatient tertiary care hospital (n = 102) over a 3-year period. These included anterior lumbar interbody fusion (ALIF), artificial disc replacement (ADR), and hybrids. Patients undergoing simultaneous or staged posterior procedures within 3 months were excluded. Patient demographics and surgical parameters between the two surgical settings were compared. Ninety-day medical complications and readmission rates were assessed. One-way analysis of variance and Chi-square analysis were used. A P value of less than .05 was considered statistically significant. RESULTS: The two study groups had similar baseline characteristics. While there was a trend toward fewer complications, reoperations, and readmissions for the ASC cohort, the differences were not statistically significant. There were 7 intraoperative complications (5.6% minor vascular injury) in the inpatient cohort and 0 in the ASC cohort. The overall 90-day postoperative complication rate was 5.6% for the inpatient cohort and 0.9% for the ASC cohort. The 90-day readmission rate was 1.9% in the ASC cohort and 1.6% in the inpatient cohort. The 90-day reoperation rate was 0.8% for the inpatient cohort and 0% in the ASC cohort. The average hospital stay was 2.3 ± 1.5 days for the inpatient cohort. CONCLUSION: The 90-day readmission rates were lower for outpatients than for inpatients, while the complication and reoperation rates were similar. Our results demonstrate that anterior lumbar procedures, including single-level and multilevel ALIF, ADR, and hybrid procedures, can be performed safely in an ASC. This has significant cost savings implications for the ASC setting.

Analysis of Spino-Pelvic Parameters and Segmental Lordosis with L5-S1 Oblique Lateral Interbody Fusion at the Bottom of a Long Construct in Circumferential Minimally Invasive Surgical Correction of Adult Spinal Deformity.

BACKGROUND: Lateral interbody fusion (LIF) is an effective adjuvant for circumferential minimally invasive surgery (CMIS) treatment of adult spinal deformity (ASD). Accessing L5-S1 via an oblique LIF (OLIF) approach (OLIF 5-1) allows for anterior LIF (ALIF) at the lumbosacral junction without repositioning the patient. We review the early outcomes and complications of OLIF 5-1 at the bottom of a long construct for an MIS approach to treat ASD. METHODS: We queried a prospectively collected registry of 111 consecutive patients with ASD (Cobb angle >20°, sagittal vertical alignment [SVA] >50, or pelvic incidence [PI]-lumbar lordosis [LL] mismatch>10) patients who underwent CMIS correction between January 2015 and January 2019. Sixty patients had ≥4 levels fused and OLIF 5-1. Multilevel pre-psoas LIF + OLIF 5-1 were performed in the first stage. Three days later, stage 2 involved MIS installation of pedicle screws with aggressive rod contouring and derotation/translation. RESULTS: The mean patient age was 66.8 years (range, 48-79 years), and the mean duration of follow-up was 24 months (range, 3-60 months). A mean of 7 levels were fused (range, 4-9). Significant improvements in L5-S1 segmental lordosis (SL), LL, SVA, PI-LL mismatch, and pelvic tilt were seen following the first stage (P < 0.05). There was no intraoperative vascular, ureteral, or sympathetic chain injury, and no transient or permanent lumbar plexopathy. In 2 patients, OLIF 5-1 was abandoned due to difficult access, and transforaminal LIF was done at L5-S1 at the second stage. Five patients required intraoperative transfusion. No patient experienced postoperative ileus or L5-S1 pseudarthrosis. Significant improvements in visual analog scale pain score, Oswestry Disability Index, 36-Item Short Form Health Survey, and Scoliosis Research Society Outcomes Questionnaire were found. CONCLUSIONS: A single-position MIS OLIF 5-1 at the bottom of a long construct in conjunction with multilevel pre-psoas LIF seems to be a safe and effective technique for improving SL, global LL, and SVA with a low risk of perioperative and postoperative complications.

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.

Correlation of weightbearing radiographs and stability of stress positive ankle fractures.

BACKGROUND: A positive external rotation stress test has been used as an indication for operative treatment of fractures of the lateral malleolus. The objective of the current study was to ascertain the results of a protocol initially treating stress positive ankle fractures nonoperatively and utilizing weightbearing radiographs in surgical decision making. METHODS: We performed a prospective study of lateral malleolar fractures with an associated medial ligamentous injury. All patients with fractures of the lateral malleolus with medial sided symptoms and/or signs, and an intact ankle mortise underwent an external rotation stress test to confirm injury to the deltoid ligament (stress positive). Patients with a positive stress test were placed in a short-leg walking cast and seen in 7 days where weightbearing radiographs of the ankle were obtained. If the radiographs demonstrated an intact mortise, then nonoperative treatment was continued. If the weightbearing radiographs demonstrated medial clear space widening, then the patient was offered operative treatment to restore the congruency of the ankle mortise. Patients were assessed for conversion to operative treatment, complications, and functional outcome. Thirty-eight patients were enrolled in the study. Using Lauge-Hansen classification 36 (95%) were stress positive supination-external rotation fractures and 2 (5%) were stress positive pronation-external rotation fractures. Followup assessment was performed at a minimum of 6 months and averaged 12 months. RESULTS: Weightbearing radiographs at the first post-injury clinic visit had an average medial clear space of 2.9 ±0.9 mm. Three (8%) patients met our criteria for medial clear space widening and underwent operative treatment. Of these three patients, two were pronation-external rotation fracture patterns. Therefore, 3% of the supination-external rotation IV fractures, and all of the pronation-external III/IV rotation fractures ultimately required operative treatment. At final followup, the average AOFAS hindfoot score was 92 ±8.1. CONCLUSION: Ligamentous supination-external rotation Stage IV fractures with an intact mortise on static radiographs can be initially treated nonoperatively. Weightbearing radiographs should be utilized to assess congruency of the ankle mortise during an early post-injury visit. Utilizing this approach, a significant number of surgeries were avoided, and good to excellent results were obtained. From our early experience, nonoperative treatment of pronation-external rotation III/IV injuries using this protocol is not recommended.