Faculty Bibliography

Study Design/UNASSIGNED:Retrospective study of consecutive patients at a single institution.Objective: Examine the effect of minimally invasive surgery (MIS) versus open transforaminal lumbar interbody fusion (TLIF) surgery on long-term postoperative narcotic consumption. Objective/UNASSIGNED:Examine the effect of minimally invasive versus open TLIF on short-term postoperative narcotic consumption. Methods/UNASSIGNED:Differences between MIS and open TLIF, including inpatient opioid and nonopioid analgesic use, discharge opioid use, and postdischarge duration of narcotic usage were compared using appropriate statistical methods. Results/UNASSIGNED:= .018) compared with MIS TLIF. Conclusion/UNASSIGNED:Patients undergoing MIS TLIF required less inpatient opioids and had a decreased incidence of opioid dependence at 3-month follow-up. Patients with preoperative opioid use undergoing MIS TLIF are less likely to require long-term opioids.

In the current value-based healthcare climate where spine surgery is shifting to the ambulatory setting, factors influencing postop length of stay (LOS) are important to surgeons and hospital administrators. Pre-op patient factors including diagnosis of radiculopathy and myelopathy have yet to be investigated in this context. Operative pts ≥ 18Y with primary diagnoses of cervical myelopathy (M), radiculopathy (R), or myeloradiculopathy (MR) were included and propensity score matched by invasiveness score (Mirza et al.). Top-quartile LOS was defined as extended. M&R patients were compared using Chi² & independent t-tests. Univariate tests assessed differences in preop patient and surgical data in M&R pts and extended/non-extended LOS. Stepwise regression analysis explored factors predictive of LOS. 718 operative pts (54.5 yrs, 41.1%F, 29.1 kg/m², mean CCI 1.11) included (177 M, 383 R, and 158 MR). After PSM, 345 patients remained (115 in each diagnosis). 102 patients had E-LOS (Avg: 5.96 days), 41 M patients (mean 7.1 days), 28 R (5.9 days), and 33 MR (4.6 days). Regression showed predictors of E-LOS in R pts (R²â€¯= 0.532, p = 0.043): TS-CL, combined and posterior approach, LIV, UIV, op time, Lactated Ringer's, postoperative complications. Predictors of E-LOS in M pts (R²â€¯= 0.230, p < 0.001): age, CCI, combined and posterior approach, levels fused, UIV, EBL, neuro and any postop complications. Predictors of E-LOS in MR patients (R²â€¯= 0.152, p < 0.001): age, kyphosis, combined approach, UIV, LIV, levels fused, EBL and op time. Independent of invasiveness, patients with a primary diagnosis of myelopathy, though older aged and higher comorbidity profile, had consistently longer overall postop LOS when compared to radiculopathy or myeloradiculopathy patients.

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)
Copyright

BACKGROUND CONTEXT: As the opioid crisis has gained national attention, there has been an increasing effort to decrease opioid usage. Simultaneously, patient satisfaction is a crucial metric in the American health care system, and has been closely linked to effective pain management in surgical patients. PURPOSE: Examine rates of pain medication prescription and concurrent patient satisfaction in spine surgery patients. STUDY DESIGN/SETTING: Retrospective cohort study. PATIENT SAMPLE: A total of 1,729 patients undergoing any spine surgery. OUTCOME MEASURES: Rates of non-opioid pain medication prescriptions during hospitalization as part of a multimodal analgesia regimen, morphine milligram equivalents (MME) of opioids used during hospitalization, Press Ganey Satisfaction Survey data.
METHOD(S): Patients >=18yo undergoing spine surgery between 6/25/2017-6/30/2018 at a single institution by spine surgeons performing >=20 surgeries/quarter and who had medication data during hospitalization available included. Additional data collected included physician and procedure type. All data analyzed by quarter. Chi-squared test to compare percentages and ANOVA to compare means across quarters. Multivariate regression used to compare procedure-specific trends, controlling for age, revision and level of pain. Significance set at p<0.05.
RESULT(S): A total of 1,759 patients were included, 427 in Quarter 1 (Q1), 439 in Q2, 453 in Q3 and 440 in Q4. Mean total MME per patient hospitalization was 574.46, no significant difference between quarters (p=0.116). Mean MME/day per patient decreased between quarters (p=0.048), with highest mean 91.84 in Q2 and lowest 77.50 in Q4. From Q1 to Q4, three physicians had decreased mean MME/day (75.47->50.92, p=0.023; 115.70->46.05, p=0.013; 92.89->69.53, p=0.42, respectively) and two physicians had decreased total MME (815.88->243.15, p=0.004; 706.79->451.72, p=0.014, respectively). MME/day decreased (74.78->52.37, p=0.046) for discectomy cases. Controlling for age, revision and level of pain, total MME decreased for discectomies (p=0.006). Among all procedures, acetaminophen, NSAID and steroid prescription rates increased (9.13%->17.05%, p=0.001; 6.32%->9.77%, p=0.048; 9.13%->17.05%, p=0.001, respectively). This was also the case in fusion patients specifically (9.09%->17.99%, p=0.002; 2.77%->5.76%, p=0.024; 9.09%->17.99%, p=0.002, respectively). NSAID prescription in laminectomy patients also increased (3.23%->4.89%, p=0.041). Concurrently, benzodiazepine and GABA analog prescriptions decreased among all procedures (19.20%->10.68%, p<0.001; 9.84%->4.77%, p=0.025, respectively). Benzodiazepine prescriptions in fusion patients also decreased (24.51%->12.23%, p<0.001). No significant differences between quarters for mean pain ratings (p=0.521). Also no differences between quarters for responses to questions from Press Ganey Satisfaction Survey regarding how often staff talk about pain (p=0.164), whether staff talk about pain treatment (p=0.595) or recommending the hospital (p=0.096). This was also the case for top box ratings for the same questions (p=0.381, 0.837, 0.610, respectively). No significant differences between quarters for responses in all other patient satisfaction questions (range p=0.359-0.988) or their top box ratings (range p=0.359-0.988).
CONCLUSION(S): Over the studied time period, opioid use decreased and nonopioid prescriptions increased during hospitalization, while satisfaction scores remained unchanged. These findings indicate an increasing effort in reducing opioid use amongst providers, and suggest the ability to do so without impacting overall satisfaction rates. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: Numerous advances have been made in the field of spine fusion, such as minimally invasive (MIS) or robotic assisted spine surgery. However, it is unknown how these advances have impacted the cost of care. PURPOSE: Compare the economic outcomes of lumbar spine fusion between open, MIS and robotic assisted surgery patients. STUDY DESIGN/SETTING: Retrospective review of a single center spine surgery database. PATIENT SAMPLE: A total of 360 propensity matched patients. OUTCOME MEASURES: Costs, EuroQol-5D (EQ5D), Cost per quality adjusted life years (QALY).
METHOD(S): Inclusion criteria: surgical patients >18 years undergoing lumbar fusion surgery. Patients were categorized into 3 groups based on procedure type: open, MIS or robotic. Open patients undergoing poster spinal fusion were considered as the control group. MIS patients included those undergoing transforaminal or lateral lumbar interbody fusion with percutaneous screws. Robotic patients were those undergoing robot assisted fusion. Propensity score matching was performed between all groups for the number of levels fused. Costs were calculated using the PearlDiver database, which reflects both private insurance and Medicare reimbursement claims for ICD-9 codes. For robot cases, costs were reflective of operational fees and initial purchase cost. Complications and comorbidities (CC) and major complications and comorbidities (MCC) were assessed according to CMS.gov manual definitions. QALYs and cost per QALY were calculated using a 3% discount rate to account for residual decline to life expectancy (78.7 years). Costs per QALY were calculated for both 1 year and life expectancy, assuming no loss of benefit.
RESULT(S): A total of 360 propensity matched patients (120 open, 120 MIS, 120 robot) met inclusion. Descriptive statistics for the cohort were: age 58.8+/-13.5, 50% women, BMI 29.4+/-6.3, op time 294.4+/-119.0, LOS 4.56+/-3.31 days, EBL 515.9+/-670.0 cc, and 2.3+/-2.2 average levels fused. Rates of postop complications were significantly higher in robotic cases versus open and MIS (43% vs. 21% and 22% for open and MIS, p<0.05). However, revision rates were comparable between all groups (3% open, 3% MIS, 5% robotic, p>0.05). After factoring in complications, revisions, and purchasing and operating fees, the costs of robotic cases was significantly higher than both open and MIS surgery ($60,047.01 vs. $42,538.98 open and $41,471.21 MIS). In a sub analysis of 42 patients with BL and 1Y EQ5D data, the cost per QALY at 1Y for open, MIS, and robot assisted cases was $296,624.48, $115,911.69, and $592,734.30. If utility gained was sustained to life expectancy, the cost per QALY was $14,905.75, $5,824.71, $29,785.64 for open, MIS, and robot assisted cases.
CONCLUSION(S): Numerous advances have been made in the field of spine surgery, however, there has been limited discussion of the effect these advances have on economic outcomes. When matched for levels fused, robot assisted surgery patients had significantly higher rates of complications and 30% higher costs of surgery compared to minimally invasive and open spine surgery patients. While 1 year economic outcomes weren't optimal for robotic surgery cases, the projected costs per quality adjusted life years at life expectancy were well below established acceptable thresholds. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: Although epidural steroid injection (ESI) has been shown to provide adequate pain relief for degenerative spondylolisthesis patients in treatment regimens up to months, it remains unclear whether the use of ESI affects the rate of crossover from nonoperative to operative management. PURPOSE: Investigate the relationship between epidural steroid injections and rates of surgical crossover for degenerative spondylolisthesis patients. STUDY DESIGN/SETTING: Retrospective review of prospectively collected data from 13 spine centers. PATIENT SAMPLE: Degenerative spondylolisthesis patients from both the randomized and concurrent observational cohorts of the Spine Patient Outcomes Research Trial (SPORT). OUTCOME MEASURES: Primary: Surgical crossover rates. Secondary: health related quality of life outcome (HRQL) measures (SF-36, ODI, Sciatica and Leg Pain Bothersomeness Indices), self-reported improvement METHODS: Included: surgical candidates >18yrs with degenerative spondylolisthesis. Excluded: patients receiving ESI before enrollment. Those who received ESI within 3 months of enrollment (ESI) and those who did not (no-ESI) were compared for differences in baseline characteristics. Outcomes at 1-year, 2-year, 3-year, and 4-year intervals following enrollment were assessed within operative and nonoperative groups using longitudinal mixed-effect models with random subject intercept term to account for correlations between repeated measurements. Treatment comparisons were performed at follow-up intervals. Area under the curve analysis for all time points assessed global significance of treatment.
RESULT(S): Included: 266 patients (192 no-ESI, 74 ESI). Patient groups did not differ in age, sex, BMI, or comorbidity burden (all p>0.05). No-ESI had greater baseline SF-36 body-pain scores (38+/-20 vs 30+/-16, p=0.002) and self-reported surgical preference (38% vs 11%, p<0.001). There were no differences in surgical rates within 4-years of enrollment between no-ESI and ESI patients (61% vs 62%, p=0.97). Surgical ESI and no-ESI patients did not differ in op-time, blood loss, rates of decompression, multilevel fusion or levels decompressed (all p>0.05). Surgical ESI and no-ESI patients showed no differences in postoperative HRQL changes at any follow-up interval, or in 4-year average HRQL outcomes. Non-operative no-ESI patients showed greater 4-year average improvement in SF-36 body pain (no-ESI: 17.8, ESI: 7.8, p=0.004) and physical function (no-ESI: 13.1, ESI: 4.3, p=0.005) than non-operative ESI patients. These improvements in SF-36 body pain were greater for non-operative no-ESI patients at 1-year (p=0.002) and 3-years (p=0.005); improvements in SF-36 physical function were greater for non-operative no-ESI patients at 1-year (p=0.030) and 2-years (p=0.002). Of patients that were initially non-operative, there was no difference between ESI and no-ESI groups in surgical crossover rates (ESI: 52%, no-ESI: 39%, p=0.15). For operative patients, crossover rates to non-operative treatment did not differ between ESI and no-ESI groups (ESI: 23%, no-ESI: 16%, p=0.38).
CONCLUSION(S): For surgical degenerative spondylolisthesis patients, there was no relationship between ESI and improved clinical outcomes over a 4-year study. For nonoperative patients, ESI was associated with inferior pain reduction through 3 years of follow-up; however, this was confounded by higher levels of baseline pain. ESI showed little relationship with surgical crossover. FDA DEVICE/DRUG STATUS: Unavailable from authors at time of publication.
Copyright

BACKGROUND CONTEXT: Proximal junctional kyphosis (PJK) is a devastating complication of adult spinal deformity (ASD) surgery. Optimal alignment specifications to maximize quality of life while limiting PJK have yet to be defined. Previous studies have primarily examined sagittal vertical axis (SVA) to determine likelihood of PJK. More recently, other alignment parameters such as thoracic-pelvic angles (TPAs) and age-adjusted alignment have been examined. PURPOSE: The goal of this study is to examine the relationship between GAP, TPAs, and bracing with likelihood of developing PJK. STUDY DESIGN/SETTING: A retrospective chart review was conducted to identity ASD patients with at least 1 year of radiographic follow up. PATIENT SAMPLE: Patients who underwent fusions to the pelvis and >4 levels fused from 2013 to 2018 and have 1-year postoperative alignment x-rays were included. OUTCOME MEASURES: The rate of radiographic PJK (change of 10-20degree) and severe PJK (change>20degree) was determined for each group. Reoperation rates were also collected.
METHOD(S): Surgical records were reviewed to determine patient sample. Chart and X-ray review were conducted to determine spinopelvic alignment parameters, GAP scores, bracing, and reoperation. X-rays were reviewed up to one year postoperatively in order to determine PJK.
RESULT(S): A total of 81 patients were included (mean 64y 63%F); baseline and 1-year postoperative alignment did not differ between PJK and no PJK patients. There was no PJK in 53.1%, 30.9% had PJK from 10-20degree, and 16% had sPJK. Of these, 7 patients had revision surgery: 1 for PJK and 1 for rod fracture. Postop bracing was used in 54% of patients. There was no difference in sPJK according to brace use. At baseline, 79% of patients had severely disproportioned GAP, 16% moderate, 5% proportioned. Of severely disproportioned, 63% had no change in GAP at 1 year. Improved GAP was not associated with sPJK (improved: 22% vs no change: 18%, p=.72). Greater correction of the UIV-PA was associated with a larger PJK angle change (R=.26) as was the 1 year T1-UIV angle (R=.30), both p<.05.GAP change was not correlated with PJKA change. The magnitude of T1PA correction was not associated with sPJK, p>.05.
CONCLUSION(S): There was no correlation between PJK and GAP alone or change in GAP; it is notable that these patients tended to be disproportioned pre and postop. Greater correction of UIV-PA and larger postop T1-UIV was associated with greater PJKA change; suggesting that the greater alignment correction led to greater likelihood of it failing. Our data suggest bracing was not effective in preventing PJK. These parameters may help surgeons understand alignment targets in ASD. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: The discussion regarding value based care has evolved in recent years, yet the ability to report Health Related Quality of Life (HRQoL) between different disease states has been limited by lack of validated standardized metrics to compare them. The recent advent of computer adaptive Patient Reported Outcome Information System (PROMIS), which allows for standardized assessment across health conditions, provides the ability to compare differing disease states and procedures. PURPOSE: To compare baseline and postoperative PROMIS scores for patients undergoing common single-level spinal surgery procedures, total hip arthroplasty (THA) and total knee arthroplasty (TKA). STUDY DESIGN/SETTING: Retrospective clinical cohort study of patients undergoing common single-level spine surgery procedures, THA and TKA at 6-month postoperative follow-up. PATIENT SAMPLE: A total of 505 orthopedic surgical patients were included who underwent either: single level anterior cervical discectomy and fusion (ACDF, N=37), lumbar laminectomy (Lami, N=31), microscopic lumbar discectomy (MLD, N=58), transforaminal lumbar interbody fusion (TLIF, N=46), total hip arthroplasty (THA, N=131), or total knee arthroplasty (TKA, N=202) at a single institution. OUTCOME MEASURES: Baseline (BL) and 6 month (6M) PROMIS metrics (Physical Function, Pain Interference, Pain Intensity). Patients were compared by T-values, which is age and gender adjusted to give a normal distribution of the general population, as the mean is scored at 50, and each 10 point deviation reflects 1SD of the population in improving or worsening function.
METHOD(S): Patients>18 years old who underwent spine surgery (ACDF, Lami, MLD, TLIF) or adult reconstruction surgery (THA or TKA) with BL & 6M PROMIS scores of physical function, pain interference and pain intensity were separately grouped based on surgery type. Paired t-tests compared differences in BL, 6M and the change in PROMIS scores for spine vs adult reconstruction procedures.
RESULT(S): A total of 172 spine surgery patients (age=54.6+/-15.6; 42.9% female) and 333 adult reconstruction patients were compared (age=65.8+/-9.5; 59.8% female). Spine surgery patients were significantly younger (p<.01) than adult reconstruction patients. Spine surgery patients undergoing ACDF, laminectomy, MLD or TLIF all had more disability and pain at baseline than THA and TKA patients, according to physical function ([20.1, 8.71, 14.2, 9.26] vs [35.9, 35.01], p<.01), pain interference ([84.1, 89.8, 91.8, 91.0)]vs [63.9, 63.8], p<.01) and pain intensity metrics ([53.6, 58.1, 58.2, 56.1] vs [53.4, 53.8], p<.01). At 6M, spine surgery patients remained more disabled and had more pain compared to adult reconstruction patients; However, patients across all spine procedures experienced greater improvements than THA and TKA patients in terms of physical function ([+8.1, +12.1, +15.2, +12.9] vs [+5.24, +3.9], p<.01) and pain interference scores ([-15.1, -14.1, -12.5, -11.9] vs [-8.1, -6.0] p<.01). Similar improvements in pain intensity scores were seen.
CONCLUSION(S): Patients undergoing single level spinal surgery had lower initial and 6 month postoperative PROMIS scores compared to those undergoing total hip and knee arthroplasty. All procedure cohorts demonstrated meaningful improvement after orthopaedic surgical treatment, but spinal surgery patients demonstrated more improvement in physical function and pain interference scores compared to arthroplasty patients. Future study is required to assess the value base of spinal and adult reconstruction surgery, including durability. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

MINI: The ability of PROMIS to capture disability from cervical sagittal malalignment is unknown. Correlations between PROMIS domains and legacy outcome metrics with cervical sagittal alignment parameters were analyzed. PROMIS domains correlated strongly with legacy outcomes and PROMIS Pain Intensity correlated with worsening sagittal alignment in patients with cervical sagittal deformity.

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.