Faculty Bibliography

Introduction: Orthopaedic surgeons (OS) and neurosurgeons (NS) both perform cervical total disc replacement (cTDR) procedures. This study evaluated disparities in demographics, comorbidities, laboratory values, surgical and hospital-related parameters, and 30-day outcomes between OS and NS patients after single-level elective cTDR.
Method(s): The American College of Surgeons NSQIP database was used to identify single-level elective cTDR patients from 2008 to 2016. Demographics, comorbidities, laboratory values, operative- and hospital-related factors, and 30-day postoperative outcomes were compared between the OS (n = 769) and NS (n = 1,443) groups with univariate analysis. Regression models were developed to find potential predictive factors for 30-day postoperative complications.
Result(s): The OS patients were younger and more likely to be white (all, p <= 0.012). Comorbidities and preoperative laboatory values were mostly comparable, although OS patients has lower rates of diabetes mellitus (4.55% vs 8.04%; p = 0.002) and corticosteroid use (0.65% vs 2.70%; p = 0.001) than NS patients. The OS and NS patients also had comparable operative times (111 vs 112 minutes; p = 0.737), and rates of 30-day complications (1.2% vs 1.1%; p = 0.896), reoperations (0.4% vs 0.7%; p = 0.51), and readmissions (1.2% vs 1.1%; p = 0.841). Patient age was a significant predictor of major complications (odds ratio 1.079; p = 0.019) based on regression analysis, but surgeon specialty was not for any complications (p >= 0.13).
Conclusion(s): Neurosurgeons had a higher operative volume, but 30-day postoperative outcomes between the 2 groups were comparable. Surgeon specialty was not predictive for 30-day postoperative outcomes. Orthopaedic surgeons might be underperforming cTDR compared with neurosurgeons, despite comparable 30-day postoperative outcomes.
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BACKGROUND:Currently, the functional status of patients undergoing spine surgery is assessed with quality-of-life questionnaires, and a more objective and quantifiable assessment method is lacking. Dr. Jean Dubousset conceptually proposed a four-component functional test, but to our knowledge, reference values derived from asymptomatic individuals have not yet been reported, and these are needed to assess the test's clinical utility in patients with spinal deformities. QUESTIONS/PURPOSES/OBJECTIVE:(1) What are the reference values for the Dubousset Functional Test (DFT) in asymptomatic people? (2) Is there a correlation between demographic variables such as age and BMI and performance of the DFT among asymptomatic people? METHODS:This single-institution prospective study was performed from January 1, 2018 to May 31, 2018. Asymptomatic volunteers were recruited from our college of medicine and hospital staff to participate in the DFT. Included participants did not report any musculoskeletal problems or trauma within 5 years. Additionally, they did not report any history of lower limb fracture, THA, TKA, or patellofemoral arthroplasty. Patients were also excluded if they reported any active medical comorbidities. Demographic data collected included age, sex, BMI, and self-reported race. Sixty-five asymptomatic volunteers were included in this study. Their mean age was 42 ± 15 years; 27 of the 65 participants (42%) were women. Their mean BMI was 26 ± 5 kg/m. The racial distribution of the participants was 34% white (22 of 65 participants), 25% black (16 of 65 participants), 15% Asian (10 of 65 participants), 9% subcontinental Indian (six of 65 participants), 6% Latino (four of 65 participants), and 10% other (seven of 65 participants). In a controlled setting, participants completed the DFT after verbal instruction and demonstration of each test, and all participants were video recorded. The four test components included the Up and Walking Test (unassisted sit-to-stand from a chair, walk forward/backward 5 meters [no turn], then unassisted stand-to-sit), Steps Test (ascend three steps, turn, descend three steps), Down and Sitting Test (stand-to-ground, followed by ground-to-stand, with assistance as needed), and Dual-Tasking Test (walk 5 meters forwards and back while counting down from 50 by 2). Tests were timed, and data were collected from video recordings to ensure consistency. Reference values for the DFT were determined via a descriptive analysis, and we calculated the mean, SD, 95% CI, median, and range of time taken to complete each test component, with univariate comparisons between men and women for each component. Linear correlations between age and BMI and test components were studied, and the frequency of verbal and physical pausing and adverse events was noted. RESULTS:The Up and Walking Test was completed in a mean of 15 seconds (95% CI, 14-16), the Steps Test was completed in 6.3 seconds (95% CI, 6.0-6.6), the Down and Sitting Test was completed in 6.0 seconds (95% CI, 5.4-6.6), and the Dual-Tasking Test was performed in 13 seconds (95% CI, 12-14). The length of time it took to complete the Down and Sitting (r = 0.529; p = 0.001), Up and Walking (r = 0.429; p = 0.001), and Steps (r = 0.356; p = 0.014) components increased with as the volunteer's age increased. No correlation was found between age and the time taken to complete the Dual-Tasking Test (r = 0.134; p = 0.289). Similarly, the length of time it took to complete the Down and Sitting (r = 0.372; p = 0.005), Up and Walking (r = 0.289; p = 0.032), and Steps (r = 0.366; p = 0.013) components increased with increasing BMI; no correlation was found between the Dual-Tasking Test's time and BMI (r = 0.078; p = 0.539). CONCLUSIONS:We found that the DFT could be completed by asymptomatic volunteers in approximately 1 minute, although it took longer for older patients and patients with higher BMI. CLINICAL RELEVANCE/CONCLUSIONS:We believe, but did not show, that the DFT might be useful in assessing patients with spinal deformities. The normal values we calculated should be compared in future studies with those of patients before and after undergoing spine surgery to determine whether this test has practical clinical utility. The DFT provides objective metrics to assess function and balance that are easy to obtain, and the test requires no special equipment.

Study Design/UNASSIGNED:Retrospective review of a prospectively collected database. Objective/UNASSIGNED:To predict the occurrence of hospital-acquired conditions (HACs) 30-days postoperatively and to compare predictors of HACs for spine surgery with other common elective surgeries. Methods/UNASSIGNED:Patients ≥18 years undergoing elective spine surgery were identified in the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database from 2005 to 2013. Outcome measures included any HACs: superficial or deep surgical site infection (SSI), venous thromboembolism (VTE), urinary tract infection (UTI). Spine surgery patients were compared with those undergoing other common procedures. Random forest followed by multivariable regression analysis was used to determine risk factors for the occurrence of HACs. Results/UNASSIGNED:A total of 90 551 elective spine surgery patients, of whom 3021 (3.3%) developed at least 1 HAC, 1.4% SSI, 1.3% UTI, and 0.8% VTE. The occurrence of HACs for spine patients was predicted with high accuracy (area under the curve [AUC] 77.7%) with the following variables: female sex, baseline functional status, hypertension, history of transient ischemic attack (TIA), quadriplegia, steroid use, preoperative bleeding disorders, American Society of Anesthesiologists (ASA) class, operating room duration, operative time, and level of residency supervision. Functional status and hypertension were HAC predictors for total knee arthroplasty (TKA), bariatric, and cardiothoracic patients. ASA class and operative time were predictors for most surgery cohorts. History of TIA, preoperative bleeding disorders, and steroid use were less predictive for most other common surgical cohorts. Conclusions/UNASSIGNED:Occurrence of HACs after spine surgery can be predicted with demographic, clinical, and surgical factors. Predictors for HACs in surgical spine patients, also common across other surgical groups, include functional status, hypertension, and operative time. Understanding the baseline patient risks for HACs will allow surgeons to become more effective in their patient selection for surgery.

Introduction: Bariatric surgery prior to spine surgery has been shown to reduce medical complication and infection risk in morbidly obese patients. However, long-term impact of irreversible bariatric surgery (bypass, gastrectomy, diversion/switch) on complication rates and outcomes after cervical fusion (CF) for radiculopathy or myelopathy (CR, CM) is unknown.
Method(s): SPARCS was reviewed from 2009-2013 for all obese/morbidly obese patients (Obese). Patients undergoing primary CF for CR or CM were included, and patients undergoing both primary CF and irreversible bariatric surgery were identified. Patients were grouped as obese CF patients with prior bariatric surgery (BAR) or obese CF patients without bariatric surgery (No-BAR), propensity score-matched and analyzed at 90-days and 2-years. Logistic regression was performed to identify predictors for outcomes.
Result(s): 187 patients had <=90-day follow-up (BAR, n=94; No-BAR, n=93); of these, 55 had >=2-year follow-up (n=28/27). Surgical approach was comparable across cohorts. Among 90-day follow-up patients, bariatric-to-CF interval was 2-year for BAR patients. Demographic, LOS, and mortality (0%), were comparable between cohorts. BAR had comparable 90-day rates of individual/overall medical/surgical complication, total complication (3.2 vs 4.3%), readmission (9.6 vs 14%), and revision (9.6 vs 15.1%). Regression revealed BAR did not reduce 90-day adverse outcomes odds. Among patients with 2-year follow-up, bariatric-to-CF interval was 1.4Y for BAR patients; 2-year-readmission was lower for BAR patients (67.9 vs 92.6%). Regression revealed BAR reduced 2-year-readmission odds (OR=0.12, 95% CI: 0.02-0.78), both p<=0.03.
Conclusion(s): Obese/morbidly obese CF patients with CR/CM with prior bariatric surgery incurred comparable outcomes/complications through short-/mid-term follow-up. Primary CF was safe in patients at least 1.4-years after irreversible bariatric surgery.
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Study Design:Retrospective cohort study. Purpose:The aim of this study was to identify features associated with increased mortality risk in traumatic C2 fractures in the elderly, including measures of comorbidity and frailty. Overview of Literature:C2 fractures in the elderly are of increasing relevance in the setting of an aging global population and have a high mortality rate. Previous analyzes of risk factors for mortality have not included the measures of comorbidity and/or frailty, and no local data have been reported to date. Methods:This study comprises a retrospective review of 70 patients of age >65 years at Waikato Hospital, New Zealand with traumatic C2 fractures identified on computed tomography between 2010 and 2016. Demographic details, medical history, laboratory results on admission, mechanism of injury, and neurological status on presentation were recorded. Medical comorbidities were also detailed allowing calculation of the Charlson Comorbidity Index (CCI) and the modified Frailty Index (mFI). Results:The most common mechanism of injury was a fall from standing height (n=52, 74.3%). Mortality rates were 14.3% (n=10) at day 30, and 35.7% (n=25) at 1 year. Bivariate analysis showed that both CCI and mFI correlated with 1-year mortality rates. Reduced albumin and hemoglobin levels were also associated with 30-day and 1-year mortality rates. Forward stepwise logistic regression models determined CCI and low hemoglobin as predictors of mortality within 30 days, whereas CCI, low albumin, increased age, and female gender predicted mortality at 1 year. Conclusions:The CCI was a useful tool for predicting mortality at 1 year in the patient cohort. Other variables, including common laboratory markers, can also be used for risk stratification, to initiate timely multidisciplinary management, and prognostic counseling for patients and family members.

STUDY DESIGN/METHODS:Retrospective review of the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database years 2010-2015. OBJECTIVE:Investigate which short-term outcomes differ for cervical laminoplasty and laminectomy and fusion surgeries. SUMMARY OF BACKGROUND DATA/BACKGROUND:Conflicting reports exist in spine literature regarding short-term outcomes following cervical laminoplasty and posterior laminectomy and fusion. The objective of this study was to compare the 30-day outcomes for these two treatment groups for multilevel cervical pathology. METHODS:Patients who underwent cervical laminoplasty or posterior laminectomy and fusion were identified in NSQIP based on Current Procedural Terminology (CPT) code: Laminoplasty 63050 and 63051, Posterior cervical laminectomy 63015 and 63045, and instrumentation 22842. Propensity-adjusted multivariate regressions assessed differences in postoperative length of stay, adverse events, discharge disposition, and readmission. RESULTS:3796 patients were included: 2397 (63%) underwent cervical laminectomy and fusion and 1399 (37%) underwent cervical laminoplasty. Both groups were similar in age, gender, BMI, ASA, CCI and had similar rates of malnutrition, chronic kidney disease, diabetes, chronic obstructive pulmonary disease, and history for steroid use. Age > 70 and age <50 were not associated with one treatment group over the other (P>0.05). Compared with laminoplasty patients, laminectomy and fusion patients had increased lengths of stay (LOS) (4.5 vs 3.7 days, P<0.01) and increased rates of adverse events (41.7 vs 35.9%, P < 0.01), discharge to rehab (16.4 vs 8.6%, P < 0.01) and skilled nursing facilities (12.2 vs 9.7%, P = 0.02), and readmission (6.2 vs 4.5%, P = 0.05). Both groups experienced similar rates of death, pulmonary embolus, deep vein thrombosis, deep and superficial surgical site infection, and reoperation (P > 0.05 for all). CONCLUSIONS:Posterior cervical laminectomy and fusion patients were found to have increased LOS, readmissions, and complications despite having similar pre-op demographics and comorbidities. Patients and surgeons should consider these risks when considering surgical treatment for cervical pathology. LEVEL OF EVIDENCE/METHODS:3.

BACKGROUND:Nonroutine discharge, including discharge to inpatient rehab and skilled nursing facilities, is associated with increased cost-of-care. Given the rising prevalence of cervical deformity (CD)-corrective surgery and the necessity of value-based healthcare, it is important to identify indicators for nonroutine discharge. OBJECTIVE:To identify factors associated with nonroutine discharge after CD-corrective surgery using a statistical learning algorithm. METHODS:A retrospective review of patients ≥18 yr with discharge and baseline (BL) radiographic data. Conditional inference decision trees identified factors associated with nonroutine discharge and cut-off points at which factors were significantly associated with discharge status. A conditional variable importance table used nonreplacement sampling set of 10 000 conditional inference trees to identify influential patient/surgical factors. The binary logistic regression indicated odds of nonroutine discharge for patients with influential factors at significant cut-off points. RESULTS:Of 138 patients (61 yr, 63% female) undergoing surgery for CD (8 ± 5 levels; 49% posterior approach, 16% anterior, and 35% combined), 29% experienced nonroutine discharge. BL cervical/upper-cervical malalignment showed the strongest relationship with nonroutine discharge: C1 slope ≥ 14°, C2 slope ≥ 57°, TS-CL ≥ 57°. Patient-related factors associated with nonroutine discharge included BL gait impairment, age ≥ 59 yr and apex of CD primary driver ≥ C7. The only surgical factor associated with nonroutine discharge was fusion ≥ 8 levels. There was no relationship between nonhome discharge and reoperation within 6 mo or 1 yr (both P > .05) of index procedure. Despite no differences in BL EQ-5D (P = .946), nonroutine discharge patients had inferior 1-yr postoperative EQ-5D scores (P = .044). CONCLUSION/CONCLUSIONS:Severe preoperative cervical malalignment was strongly associated with nonroutine discharge following CD-corrective surgery. Age, deformity driver, and ≥ 8 level fusions were also associated with nonroutine discharge and should be taken into account to improve patient counseling and health care resource allocation.

BACKGROUND:Interplay between degenerative hip and spine conditions (Hip-Spine Syndrome [HiSS]) warrants effective communication between respective surgeons. We identified radiographic parameters to distinguish a subset of patients with HiSS by evaluating hip osteoarthritis (HOA) in patients with and without spinopelvic malalignment, categorizing patients into respective HiSS types, and comparing radiographic parameters. METHODS:All patients with full-body orthogonal radiography from 2013 to 2016 were reviewed (n = 1,389). Using sagittal/coronal hip radiographs, HOA (Kellgren-Lawrence Grade) was noted, and pelvic incidence-lumbar lordosis mismatch (PI-LL) > 10° was considered spinal malalignment. Patients groups included non-HiSS (PI-LL ≤ 10°/Grade 0/n = 444), Hip (PI-LL ≤ 10°/Grade 3-4/n = 78), Spine (PI-LL > 10°/Grade 0/n = 297), or Hip-Spine (PI-LL > 10°/Grade 3-4/n = 30). Parameters were compared using ANOVA with post-hoc Bonferroni analysis. RESULTS:HiSS Hip type patients had less hip extension capability compared with non-HiSS, Spine, and Hip-Spine type patients, reflected by lowest pelvic tilt (PT)/sagittal retroversion (11.3° versus 16.5°/29.2°/25.2°, respectively) and less hip extension per sacrofemoral angle (10.1° versus 19.5°/28.4°/23.1°, respectively) (P < 0.001), as well as 4.7° increase in anterior tilt/sagittal anteversion compared with age-matched individuals. Hip-Spine type patients had less pelvic retroversion than Spine type patients (P = 0.045); these differences were greater when referenced to age-matched individuals (P < 0.001). Hip-Spine type patients had less hip extension than Spine type patients (P = 0.013). Hip type patients had greater knee flexion than non-HiSS type patients (6.4° versus 2.6°; P < 0.001). Moreover, Hip-Spine type patients had comparable lower extremity alignment compared with Spine type patients, except for greater posterior pelvic shift. CONCLUSION/CONCLUSIONS:Our novel HiSS categorization used established classification methods and supported PT use to potentially improve the ability to discern HiSS types/pathologies in a subset of patients with HOA and spinal sagittal malalignment. HOA grade 3 to 4 with PT <15° are categorized as Hip type and those with PT >25° are Hip-Spine type with sagittal malalignment, which may impact acetabular arthroplasty component placement.

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.