Faculty Bibliography

STUDY DESIGN/UNASSIGNED:Retrospective clinical review. OBJECTIVE/UNASSIGNED:To assess the use of intraoperative computed tomography (CT) image-guided navigation (IGN) and robotic assistance in posterior lumbar surgery and their relationship with patient radiation exposure and perioperative outcomes. METHODS/UNASSIGNED:Patients ≥18 years old undergoing 1- to 2-level transforaminal lateral interbody fusion in 12-month period were included. Chart review was performed for pre- and intraoperative data on radiation dose and perioperative outcomes. All radiation doses are quantified in milliGrays (mGy). Univariate analysis and multivariate logistic regression analysis were utilized for categorical variables. One-way analysis of variance with post hoc Tukey test was used for continuous variables. RESULTS/UNASSIGNED:= .313, .051, and .644, respectively). CONCLUSION/UNASSIGNED:IGN and robotic assistance in posterior lumbar fusion were associated with higher intraoperative and total-procedure radiation exposure than open cases without IGN/robotics, but significantly less than MIS without IGN/robotics, without differences in perioperative outcomes. Fluoro-MIS procedures reported highest radiation exposure to patient, and of equal concern is that the proportion of total radiation dose also applied to the surgeon and operating room staff in fluoro-MIS group is higher than in IGN/robotics and open groups.

Robotic spine surgery has a number of potential advantages, including more precise preoperative planning, a high degree of accuracy in pedicle screw placement, and significantly reduced radiation exposure to the surgical team. Despite the potential advantages, many surgeons feel that it is still too early for the widespread adoption of this technology, citing increased cost, increased operating room time, and lack of necessity. Most spine surgeons will agree, however, that robotic technology is still in its infancy and that there will be a significant role for this technology in the future. Amidst this debate, it is important to understand the evolution of this technology from its initial inception to the present day, with a critical appraisal of the technology in its current form. It is important to consider the probable next steps in the development of this technology so that we may develop and shape this technology to most benefit our patients. This article reviews the history and development of robotic technology in spine surgery, critically assesses the technology in its current form, and explores the future directions.

Background/UNASSIGNED:Robotic-guided navigation systems for pedicle screw placement has gained recent interest to ensure accuracy and safety and diminish radiation exposure. There have been no published studies using a new combined robotics and navigation system (Globus ExcelsiusGPS system). The purpose of this study was to demonstrate safety with this system. Methods/UNASSIGNED:This is a case series of consecutive patients at a single institution from February 1, 2018, to August 31, 2018. All patients who had planned placement of thoracic and lumbar pedicle screws using the combined robotics-navigation system were included. Chart review was performed for operative details. A subgroup analysis was performed on patients with postoperative computed tomography (CT) scans to assess screw placement accuracy using the Gertzbein and Robbins system. Acceptable pedicle screw position was defined as grade A or B. Results/UNASSIGNED:One hundred six patients were included, with 636 pedicle screws, 6 iliac screws, and 1 S2AI screw. Five cases were aborted for technical issues. In the remaining 101 patients, 88 patients had screws placed using preoperative CT planning and 13 patients using intraoperative fluoroscopy planning. All screws except for 5 pedicle screws in 2 patients were placed successfully using the robot (99%). These 5 pedicle screws were placed by converting to a fluoro-guided technique without robotic assistance. Eighty-six patients had screws placed using a percutaneous technique, and 15 patients had screws placed using an open technique. Ninety-eight patients underwent interbody placement: 28 anterior lumbar interbody fusions (ALIFs), 12 lateral lumbar interbody fusions (LLIFs), and 58 transforaminal lumbar interbody fusions (TLIFs). All ALIFs and LLIFs were performed prior to placement of the screws. Four LIF patients had screws placed in the lateral position. No patients had screw-related complications intraoperatively or postoperatively, and no patients returned to the operating room for screw revision. Thirteen patients underwent postoperative CT for various reasons. Of the 66 pedicle screws that were examined with postoperative CT, all screws (100%) had acceptable position. Conclusion/UNASSIGNED:This study demonstrates that the combined robotics and navigation system is a novel technology that can be utilized to place pedicle screws and pelvic screws safely and has the potential to reduce screw-related complications. Level of Evidence/UNASSIGNED:4 (case series).

BACKGROUND CONTEXT: Intraoperative CT image-guided navigation (IGN) and robotic assistance have been increasingly implemented during spine surgery to improve accuracy in pedicle screw positioning. However, studies have shown that they increase operative time and ionizing radiation exposure, and it remains controversial whether they improve patient outcomes. PURPOSE: Assess use of IGN and robotic assistance in posterior lumbar surgery and their relationship with patient radiation exposure and perioperative outcomes. STUDY DESIGN/SETTING: Retrospective cohort study at single institution. PATIENT SAMPLE: A total of 165 patients undergoing 1- or 2-level posterior spinal fusion, with or without TLIF. OUTCOME MEASURES: Preoperative CT scan utilization and radiation dose, intraoperative radiation dose (fluoroscopy and/or CT) and total-procedure radiation dose (sum of preoperative CT and intraoperative radiation doses), levels fused, operative time, estimated blood loss (EBL), length of stay (LOS), postoperative complications.
METHOD(S): Patients >=18 years old undergoing 1- or 2-level posterior spinal fusion, with or without TLIF, in a 12-month period included. Chart review performed for pre- and intraoperative data on radiation dose and perioperative outcomes. All radiation doses quantified in milli-Grays (mGy). Univariate analysis and multivariate logistic regression analysis for categorical variables and one-way ANOVA for continuous variables utilized, with significance set at p<0.05.
RESULT(S): A total of 165 patients (51.83% F, 59.13+/-13.18yrs, BMI 29.43+/-6.72, Charlson comorbidity index [CCI] 1.20+/-1.56) were assessed: 12 IGN, 62 robotic, 56 open, 35 MIS without IGN/robotics. Lower proportion of women in open and MIS group (66.67% F IGN, 64.52% robotic, 38.18% open, 45.71% MIS, p=0.010). Younger patients in MIS group (63.42 yrs IGN, 61.74 robotic, 60.63 open, 50.63 MIS, p<0.001). MIS group had lowest mean posterior levels fused (1.42 IGN, 1.27 robotic, 1.32 open, 1.06 MIS, p=0.015). Total-procedure radiation (50.21mGy IGN, 59.84 robotic, 22.56 open, 82.02 MIS), total-procedure radiation/level fused (41.88mGy IGN, 51.18 robotic, 18.56 open, 79.41 MIS) and intraop radiation (44.69mGy IGN, 44.85 robotic, 14.81 open, 80.28 MIS) were lowest in the open group and highest in the MIS group compared to IGN and robotic (all p<0.001). A higher proportion of robotic and lower proportion MIS patients had preop CT (25% IGN, 82.26% robotic, 37.5% open, 8.57% MIS, p<0.001). EBL (441.67mL IGN, 380.24 robotic, 355.36 open, 162.14 MIS, p=0.002) and LOS (4.75 days IGN, 3.89 robotic, 3.89 open, 2.83 MIS, p=0.039) were lowest in the MIS group. Highest operative time for IGN patients (303.5 min vs 264.85 robotic, 229.91 open, 213.43 MIS p<0.001). No differences in BMI, CCI, postoperative complications (p=0.313, 0.051, 0.644, respectively).
CONCLUSION(S): IGN and robotic assistance in posterior lumbar fusion were associated with higher intraoperative and total-procedure radiation exposure than open cases without IGN/robotics, but significantly less than MIS without IGN/robotics, without differences in perioperative outcomes. While MIS procedures reported highest radiation exposure to patient, of more concern is that the proportion of total radiation dose applied to surgeon would also be considerably higher in MIS group. FDA DEVICE/DRUG STATUS: Brainlab Airo Mobile Intraoperative CT scanner (Approved for this indication).
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BACKGROUND CONTEXT: Lateral interbody fusion (LLIF) is often performed with biologic adjuvants to promote fusion. Commercially available bone allograft containing allogeneic stem cells (ASC) and bone morphogenetic protein-2 (BMP) are designed to promote fusion while avoiding the morbidity of iliac crest autograft; however, no study to date has directly compared the two in LLIF. The ASC studied is Osteocel Pro (NuVasive, Inc). PURPOSE: This non-industry funded study compares fusion rate, complications, and costs between LLIF with BMP and ASC. STUDY DESIGN/SETTING: Single center retrospective comparative study. PATIENT SAMPLE: Patients with 1-3 lumbar levels treated with LLIF. OUTCOME MEASURES: Outcomes measures are fusion at 1 year postoperative, complication rates, length of stay, and costs.
METHOD(S): A retrospective chart review was conducted to identify patients treated with LLIF and ASC or BMP from February 2012 through September 2017. Patients were included who had from 1-3 lumbar levels treated with LLIF and at least 1 year of radiographic follow up. Interbody fusion was assessed on lumbar X-ray images using a validated scale.
RESULT(S): A total of 94 patients were included representing 162 levels fused. Of these, 74 patients and 133 levels were treated with BMP; 20 patients and 29 levels were treated with ASC. Comparing patients treated with BMP or ASC, there were no differences in age [61.6 vs 60.4, p=0.7], BMI [29.8 vs 28.3, p=0.3], gender [60.8% vs 55.0% female], smoking status [12.2% vs 10.0%, p=1], diabetes [28.4% vs 15.0%, p=0.2], Charleston Comorbidity Index [4.3 vs 3.5, p=0.2], revision status [47.3% vs 45.0%, p=0.9], intraoperative complications [4.1% vs 5.0%, p=1], postoperative complications [37.8% vs 30.0%, p=0.5], or blood loss [881 vs 528ml, p=0.2]. More levels were fused in the BMP group (1.8 vs 1.45, p=0.04) and the BMP group tended toward a longer length of stay [4.8 vs 3.8 days, p=0.06]. There was a nonsignificant trend toward a higher fusion rate with BMP vs ASC[98.5% vs 93.1%, p=0.1]. The average amount of rhBMP used per level was 2.0 cc compared to 5.9 cc of ASC. There was no difference in the cost of the BMP per level compared with ASC [4.45% vs 4.80%, p=0.33], but the BMP group tended toward a higher cost of total care [103.5% vs 87.6%, p=0.1].
CONCLUSION(S): ASC and BMP are both acceptable adjuvants in LLIF that demonstrate comparable fusion rates at 1 year with comparable cost in the setting of similar groups of patients. The radiographic fusion rate seen in our study compares to previous reports in the literature using ASC. Cost considerations are becoming ever more cogent in spine surgery; the results of this study can inform decision making regarding which biologic adjuvant to use in lumbar interbody fusion. FDA DEVICE/DRUG STATUS: Osteocel (Approved for this indication), rhBMP (Infuse) (Not approved for this indication)
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STUDY DESIGN/METHODS:Retrospective cohort study. OBJECTIVE:The goals of this study were to (1) evaluate pre-operative bone quality assessment and intervention practice over time and (2) review the current evidence for bone evaluation in spine fusion surgery. SUMMARY OF BACKGROUND DATA/BACKGROUND:Deformity spine surgery has demonstrated improved quality of life in patients however its cost has made it controversial. If pre-operative bone quality can be optimized then potentially these treatments could be more durable however, at present, no clinical practice guidelines have been published by professional spine surgical organizations. METHODS:A retrospective cohort review was performed on patients who underwent a minimum five-level primary or revision fusion. Pre-operative bone quality metrics were evaluated over time from 2012 - 2017 to find potential trends. Sub-group analysis was conducted based on age, gender, pre-operative diagnosis, and spine fusion region. RESULTS:Patient characteristics including pre-operative rates of pseudarthrosis and junctional failure did not change. An increasing trend of physician bone health documentation was noted (p = 0.045) but changes in other metrics were not significant. A gender bias favored females who had higher rates of pre-operative DXA studies (p = 0.001), Vitamin D 25-OH serum labs (p = 0.005), Vitamin D supplementation (p = 0.022), calcium supplementation (p < 0.001), antiresorptive therapy (p = 0.016), and surgeon clinical documentation of bone health (p = 0.008) compared to men. CONCLUSION/CONCLUSIONS:Our spine surgeons have increased documentation of bone health discussions but this has not affected bone quality interventions. A discrepancy exists favoring females over males in nearly all pre-operative bone quality assessment metrics. Pre-operative vitamin D level and BMD assessment should be considered in patients undergoing long fusion constructs however the data for bone anabolic and resorptive agents has less support. Clinical practice guidelines on pre-operative bone quality assessment spine patients should be defined. LEVEL OF EVIDENCE/METHODS:4.

Background/UNASSIGNED:Spine surgery is associated with significant intraoperative blood loss, often leading to transfusion. Patients who receive transfusions have an increased length of stay and risk of perioperative complications. To decrease the transfusion rate, we implemented an evidence-based institution-wide restrictive transfusion blood management guideline. The goal of this study is to describe the impact of this guideline on our spine surgery patients. Methods/UNASSIGNED:We analyzed the incidence of transfusion following 3709 single-institution, inpatient spine procedures before and after implementation of a revised blood transfusion protocol. The baseline period (1742 patients) from January 2014 to March 2015 was compared to the study period (1967 patients) of April 2015 to July 2016. One patient was excluded because of incomplete medical records. The revised protocol included establishing a postoperative blood transfusion trigger at hemoglobin < 7g/dL, instituting a computerized provider order entry, and appointing a physician champion to monitor and report progress. Results/UNASSIGNED: = .01). There was no significant difference in total hospital costs following protocol implementation. Conclusions/UNASSIGNED:Implementation of a restrictive transfusion protocol through use of a computerized provider order entry and a physician champion to oversee clinician compliance led to a 40.1% reduction in blood transfusion following spine surgery. Behavior changes were visible with a 40.7% increase in hemoglobin documentation before transfusion, and patients benefited from a reduction in length of stay and postsurgical infection rate. Future study is encouraged to understand the long-term impact of this intervention and its role in hospital expenditure.

The Press Ganey survey is the most widely used instrument for measuring patient satisfaction. Understanding the factors that influence these surveys may permit better use of survey results and may direct interventions to increase patient satisfaction. Press Ganey Clinician and Group Consumer Assessment of Healthcare Providers and Systems surveys administered to ambulatory spine surgery clinic patients within a large tertiary care network from May 2016 to September 2017 were retrospectively reviewed. Mean comparison testing was performed to measure associations between patient demographics and responses to "overall provider rating" and "recommend this provider's office" survey questions. Mean difference to achieve significance was set at α<0.05. A multivariate analysis was performed to determine independent factors. A total of 1400 survey responses from the offices of 11 orthopedic spine surgeons were included. Patients 18 to 34 years old had significantly lower responses to the overall provider rating question than older patients (P<.001), and increasing patient age was correlated with improved ratings. Highest education level was inversely correlated with satisfaction scores, with patients who had attained graduate level education having the lowest satisfaction scores (P=.001). Those with commercial insurance had significantly lower ratings for recommend this provider's office (P=.042) and overall provider rating (P=.022) questions than those with other insurance types. Patients administered the survey on paper had significantly lower ratings than those administered the survey online (P=.006). Provider ratings were significantly higher when the sex and ethnicity of the patient were concordant with the provider (P=.021). This study showed that independent, nonmodifiable factors such as age, education level, and survey mode were significantly associated with the satisfaction of ambulatory spine surgery clinic patients. [Orthopedics. 2019; 42(3):143-148.].

Introduction/UNASSIGNED:This study assessed the incidence and risk factors for pseudarthrosis among primary spine fusion patients. Methods/UNASSIGNED:-tests. Binary logistic regression assessed patient-related and procedure-related predictors for pseudarthrosis. Results/UNASSIGNED:=0.026). Conclusions/UNASSIGNED:Alcoholism and surgical revision are major risk factors for pseudarthrosis in patients undergoing spine fusion.