Faculty Bibliography

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.

OBJECTIVEProximal junctional kyphosis (PJK) is a structural complication of spinal fusion in 5%-61% of patients treated for adult spinal deformity. In nearly one-third of these cases, PJK is progressive and requires costly surgical revision. Previous studies have suggested that patient body habitus may predict risk for PJK. Here, the authors sought to investigate abdominal girth and paraspinal muscle size as risk factors for PJK.METHODSAll patients undergoing thoracolumbosacral fusion greater than 2 levels at a single institution over a 5-year period with ≥ 6 months of radiographic follow-up were considered for inclusion. PJK was defined as kyphosis ≥ 20° between the upper instrumented vertebra (UIV) and two supra-adjacent vertebrae. Operative and radiographic parameters were recorded, including pre- and postoperative sagittal vertical axis (SVA), sacral slope (SS), lumbar lordosis (LL), pelvic tilt, pelvic incidence (PI), and absolute value of the pelvic incidence-lumbar lordosis mismatch (|PI-LL|), as well as changes in LL, |PI-LL|, and SVA. The authors also considered relative abdominal girth and the size of the paraspinal muscles at the UIV.RESULTSOne hundred sixty-nine patients met inclusion criteria. On univariate analysis, PJK was associated with a larger preoperative SVA (p < 0.001) and |PI-LL| (p = 0.01), and smaller SS (p = 0.004) and LL (p = 0.001). PJK was also associated with more positive postoperative SVA (p = 0.01), ΔSVA (p = 0.01), Δ|PI-LL| (p < 0.001), and ΔLL (p < 0.001); longer construct length (p = 0.005); larger abdominal girth-to-muscle ratio (p = 0.007); and smaller paraspinal muscles at the UIV (p < 0.001). Higher postoperative SVA (OR 1.1 per cm), smaller paraspinal muscles at the UIV (OR 2.11), and more aggressive reduction in |PI-LL| (OR 1.03) were independent predictors of radiographic PJK on multivariate logistic regression.CONCLUSIONSA more positive postoperative global sagittal alignment and smaller paraspinal musculature at the UIV most strongly predicted PJK following thoracolumbosacral fusion.

Background/UNASSIGNED:Regional and segmental changes of the lumbar spine have previously been described as patients transition from standing to sitting; however, alignment changes in the cervical and thoracic spine have yet to be investigated. So, the aim of this study was to assess cervical and thoracic regional and segmental changes in patients with thoracolumbar deformity versus a nondeformed thoracolumbar spine population. Methods/UNASSIGNED:This study was a retrospective cohort study of a single center's database of full-body stereoradiographic imaging and clinical data. Patients were ≥ 18 years old with nondeformed spines (nondegenerative, nondeformity spinal pathologies) or thoracolumbar deformity (ASD: PI-LL > 10°). Patients were propensity-score matched for age and maximum hip osteoarthritis grade and were stratified by Scoliosis Research Society (SRS)-Schwab classification by PI-LL, SVA, and PT. Patients with lumbar transitional anatomy or fusions were excluded. Outcome measures included changes between standing and sitting in global alignment parameters: sagittal vertical axis (SVA), pelvic incidence minus lumbar lordosis (PI-LL), pelivc tilt (PT), thoracic kyphosis, cervical alignment, cervical SVA, C2-C7 lordosis (CL), T1 slop minus CL (TS-CL), and segmental alignment from C2 to T12. Another analysis was performed using patients with cervical and thoracic segmental measurements. Results/UNASSIGNED: = .009) segments. Conclusions/UNASSIGNED:Nondeformity patients and ASD patients have significant differences in mobility of global spinopelvic parameters as well as segmental regions in the cervical and thoracic spine between sitting and standing. This study aids in our understanding of flexibility and compensatory mechanisms in deformity patients, as well as the possible impact on unfused segments when considering deformity corrective surgery.

OBJECTIVE:In the setting of a previous proximal fusion, an asymmetric 3-column osteotomy (3CO) can provide tremendous deformity correction. Our goal was to evaluate outcomes and complications of asymmetric 3CO through the proximal fusion mass, for coronal malalignment in patients with previous long thoracic fusion for adolescent idiopathic scoliosis. METHODS:This was a retrospective case series. Thirteen individuals with a history of a long thoracic fusion underwent asymmetric 3CO for persistent coronal malalignment. Clinical chart review was conducted to determine perioperative complications and radiographs evaluated for alignment. RESULTS:Thirteen patients (age: 57.8 ± 12.2 years; 0 male, 13 female) completed a mean follow-up of 42.4 months. There was significant improvement in coronal and sagittal alignment, and pelvic incidence-lumbar lordosis postoperatively (P < 0.05). One patient developed lower-extremity weakness requiring revision decompression 72 hours postoperatively; the weakness subsequently resolved. One patient had a foot drop postoperatively. At final follow-up, 12 of 13 patients had grade 1 fusion at the osteotomy site; 1 patient had a grade 2 fusion. None of the patients developed a pseudarthrosis, or superficial or deep infections. CONCLUSIONS:Patients with a history of previous thoracic fusion for adolescent idiopathic scoliosis and coronal malalignment may develop painful degeneration of the segments caudal to the fusion as adults. In this setting, extension of fusion to the sacropelvis alone may worsen the patient's coronal alignment. An asymmetric 3CO may be considered at the proximal fusion mass to achieve realignment objectives, with an acceptable complication rate and an expected improvement in outcomes.

Study Design/UNASSIGNED:Prospective cohort study. Objectives/UNASSIGNED:Most studies of dysphagia in the cervical spine have focused on a degenerative patient population; the rate of dysphagia following surgery for cervical deformity (CD) is unknown. This study aims to investigate if surgery for cervical deformity results in postoperative dysphagia. Methods/UNASSIGNED:tests, and bivariate Pearson correlations were performed. Results/UNASSIGNED:= .53). Surgical variables, including estimated blood loss (EBL), anterior or posterior fusion levels, steroid use, preoperative traction, staged surgery, surgical approach, anterior corpectomy, posterior osteotomy, and UIV (upper instrumented vertebrae) location, showed no impact on postoperative SWAL-QoL. Correction of cervical kyphosis was not correlated to 3-month SWAL-QoL scores or the change in SWAL-QoL scores. Conclusions/UNASSIGNED:While patients undergoing surgery for cervical deformity had swallowing dysfunction at baseline, we did not observe a significant decline in SWAL-QoL scores at 3 months. Patients with prior cervical surgery and higher BMI had a lower baseline SWAL-QoL. There were no surgical or radiographic variables correlated to a change in SWAL-QOL score.

OBJECT/OBJECTIVE:The LSDI assesses the impact of lumbar stiffness on activities of daily living. We hypothesized that patients <60 years-old would perceive greater lumbar stiffness-related functional limitation following fusion for adult spinal deformity. METHODS:Patients completed the LSDI and SRS-22r questionnaires preoperatively and at 2 years postoperatively. The primary independent variable was patient age <60 vs. ≥60 years-old. Multivariable regression analyses were utilized. RESULTS:In total, 267 patients were analyzed. Patients <60 years-old (51.3%) and ≥60 years-old (48.7%) were evenly represented. In bivariable analysis, patients <60 years-old exhibited lower LSDI at baseline vs. patients ≥60 years-old (25.7 vs. 35.5, β -9.8, p<0.0001), but a directionally smaller difference at 2-years (26.4 vs. 32.3, β -5.8, p=0.0147). LSDI was associated with lower SRS-22r total score among both patients <60 and ≥60 years-old, at both baseline and 2-years (all p<0.0001); the association was stronger among patients <60 vs. ≥60 years-old at 2 years. LSDI was associated with SRS satisfaction scores at 2 years among patients <60 years-old (p<0.0001), but not patients ≥60 years-old (p=0.2250). The difference in SRS satisfaction per unit LSDI between patients <60 years-old and >60 years-old was significant (p=0.0021). CONCLUSIONS:Among ASD patients managed operatively, higher LSDI was associated with inferior SRS-22r total score and satisfaction at 2 years postoperatively. The association between increased LSDI and worse PROMs was greater among patients <60 vs. ≥60 years old. Pre-operative counseling is needed for patients <60 undergoing ASD surgery regarding the effects that lumbar stiffness may have on post-operative function and satisfaction.

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.

BACKGROUND CONTEXT: Several guidelines for target-selection in the literature utilize pelvic incidence (PI) as a marker for lumbar correction. In practice, postoperative alignment is highly affected by preoperative data, including demographics and spinal flexibility. Preoperative supine radiographs allow for early visualization of patient alignment in the intraoperative position. Our objective was to determine the strongest predictor of postoperative alignment among PI, age and preoperative supine alignment using a retrospective, single center database of adult spinal deformity (ASD) patients. PURPOSE: Identify independent predictors of postoperative curvatures (LL and TK) using preoperative data only. STUDY DESIGN/SETTING: Retrospective review of a single-center database of ASD patients. PATIENT SAMPLE: A total of 99 surgically treated ASD patients with minimum 1 year follow-up. OUTCOME MEASURES: L1-S1 lordosis, T4-T12 kyphosis.
METHOD(S): Pre- to postoperative analysis was conducted using paired t-test sampling. Patients were stratified by region of fusion postoperative: complete lumbar fusion (from L1 to S1) and/or complete thoracic fusion (from T4 to T12). Pearson's r correlation analysis was performed on postoperative curvatures (LL and TK) with preoperative alignment in both standing and supine positions. Correlation analysis was repeated for LL in patients with complete lumbar fusion and for TK in patients with complete thoracic fusion. Lastly, a multilinear stepwise regression was conducted to identify independent predictors of LL or TK post-op.
RESULT(S): A total of 99 patients were included in the analysis (63.2yo, 83.1%F, 27.3kg/m2, mean f/u 21 months+/-.9.8). Preoperative SRS classification demonstrated a moderate to severe sagittal and/or coronal deformity (PT modifier: 18.2% ++, SVA: 27.3% ++, PI-LL: 29.3% ++, SRS type: 29.3% N and 68.7% L or D). Sagittal alignment significantly improved between pre- and postoperative (all p < 0.001). Of these, 73 patients (73.7%) underwent a complete fusion of the lumbar spine and 50 (50.5%) underwent a complete thoracic fusion. A total of 20.6% underwent a 3CO, and no significant difference was found in postoperative alignment between patients with and without 3CO (PI-LL: -2.6degree vs 1.8degree p = 0.175). Correlation analysis demonstrated a significant association between preoperative and postoperative LL alignment (LL Standing: 0.608; LL Supine: 0.668; PI: 0.577 all p< 0.001) as well as between pre- and postoperative TK alignment (TK Standing: 0.549; TK Supine: 0.488). Analyses were repeated on patients who underwent a complete lumbar or thoracic fusion: results demonstrated stronger associations for LL correlations (0.691, 0.716 and 0.553) and similar TK correlations (0.454 and 0.530), respectively. Multilinear regression demonstrated that only LL Supine and PI were significant predictors of postoperative LL with an r-squared of 0.568, all p< 0.01 (patient age, LL standing and TK were not significant). Similarly, LL Supine, TK Supine and patient age were the only predictors of post-op TK (r-squared 0.490, all p < 0.01).
CONCLUSION(S): Preoperative supine alignment is one of the best predictors of postoperative alignment at 1 year. When controlling for fusion location, results show an even greater importance of supine alignment, especially regarding thoracic alignment. Specific attention is required when performing thoracic fusion to avoid thoracic flattening FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: The natural shift from a flexible lordotic to relatively fixed kyphotic spine demands special consideration in cervical deformity (CD) surgery. Rigid instrumentation may alter these dynamics considerably depending on a patient's primary driver of deformity and even apex of curvature. The lower instrumented vertebrae (LIV) in CD constructs may have varying effects on patient outcomes that are still poorly understood. PURPOSE: To compare outcomes in CD patients undergoing instrumented correction according to the relation of LIV with primary driver of deformity. STUDY DESIGN/SETTING: Retrospective review of a multicenter cervical fusion dataset. PATIENT SAMPLE: Sixty-two patients undergoing cervical fusion. OUTCOME MEASURES: Baseline (BL) and postop HRQLs: mJOA, NDI, EQ5D, Numeric Rating Scale for Neck/Back pain, distal junctional kyphosis (DJK) rate and magnitude.
METHOD(S): CD database inclusion: cervical kyphosis >10degree, scoliosis (coronal Cobb>10degree), positive cervical sagittal imbalance (cSVA>4 cm or TS-CL>10degree), or CBVA>25degree. Patients were stratified by primary driver of deformity: cervical (C) via Ames classification (TS-CL>20 or cSVA>40) and thoracic (T) via hyper/hypo-kyphosis (TK) from T4-T12 (6010degree LIV and LIV+2) rate up to 1 year.
RESULT(S): Sixty-two CD patients (54.9 yrs, 62.8% F) were analyzed. Mean parameters at BL: TSCL 28.1, cSVA 26.9, T4-T12 angle 38.1. 21 pts had a C primary driver and 41 had a T primary driver by definition. One hundred percent of C primary drivers had LIVs below CL apex, while 9.2% of T primary drivers had LIVs below (caudal) to TK apex and 90.8% had LIVs above TK apex. No differences in HRQLs were found between C and T groups at BL and 3 mo postop. By 1 yr, C patients trended lower NDI (21.9 vs 29.0, p=0.245), lower NRS Neck pain (4.2 vs 5.1,p=0.358), and significantly higher EQ5D VAS (69.2 vs 52.4,p=0.040). When T pts with LIVs below TK apex were excluded, remaining T pts with LIV above apex had significantly higher 1 yr NDI than C pts (37.5vs21.9,p=.05). T patients also trended higher rates of postop DJK than C (19.5% vs 4.8%, p=0.119). No significant differences in mJOA were found (p>0.05).
CONCLUSION(S): Stopping prior to apex was more common in patients with a primary thoracic driver (T) and associated with deleterious effects. Those with a primary cervical driver (C) tended to have LIVs inclusive of CL apex with lower rates of post-op DJK. Additionally, T patients with LIVs above TK apex had significantly higher NDI and lower EQ5D VAS scores by 1-year. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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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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