Faculty Bibliography

BACKGROUND CONTEXT: The maintenance of horizontal gaze is an essential function of upright posture and global sagittal spinal alignment. Horizontal gaze is classically measured by the Chin Brow Vertical Angle (CBVA), which is not readily measured on most lateral spine radiographs. PURPOSE: This study proposes to evaluate the correlation of CBVA with two more accessible angles: the Slope of the Line of Sight (SLS) (slope of Frankfort line: anterior/inferior margin of orbit to the top of the external auditory meatus) and the slope of McGregor's line (McGS). Furthermore, this study also aims to correlate these 3 angles with HRQOL, specifically the Oswestry Disability Index (ODI). STUDY DESIGN/SETTING: Single-center, retrospective, non-consecutive case series. PATIENT SAMPLE: 531 Patients with spinal pathologies (primary cervical, lumbar, or adult scoliosis) from November 2012 to November 2013. OUTCOME MEASURES: Oswestry Disability Index (ODI). METHODS: Patients were identified from a multicenter database of 531 spine patients who underwent full body EOS X-rays with a variety of presenting complaints (primary cervical, lumbar, or adult scoliosis). Exclusion criteria were age<18y, total hip arthroplasty, total knee arthroplasty, neuropathic scoliosis, fractures, and tumor. Correlations between CBVA, SLS, and McGS and were assessed. Using a quadratic regression with ODI and CBVA, we established a low disability range of values for the CBVA and then, by simple regression, a low disability range of values for SLS and McGS. RESULTS: 435 patients were included (67% females, mean age 57 +; 15yo, mean BMI 27.4 +; 6.4 kg/m²). CBVA strongly correlated with SLS (r=.996, p<.001) and McGS (r=.862, p<.001). A significant negative correlation was observed between ODI and all 3 angles (with CBVA: r= -0.232, p=.022, with SLS: r=-0.228, p=.024, with McGS: r=-0.213, p=.036). By applying a quadratic regression on the ODI and CBVA establishing range of values corresponding to low disability (-4.7degree to 17!

BACKGROUND CONTEXT: Previous force plate studies analyzing the impact of sagittal spinal deformity (SSD) on pelvic parameters have demonstrated compensatory mechanisms of translation in addition to rotation. However, compensatory changes in the hip, knee and ankle joints have not been assessed in patients with sagittal malalignment. PURPOSE: This study aims to 1) analyze the relationship between sagittal spinopelvic (SPP) and lower limb (LLP) parameters, 2) to clarify the role of pelvic translation (pelvic shift) and 3) to correlate Oswestry Disability Index with spinopelvic parameters and compensatory mechanisms. STUDY DESIGN/SETTING: Retrospective single center study. PATIENT SAMPLE: From November 2012 to November 2013, 409 patients with spinal deformity and full-body EOS images (EOS system) were included, without age or gender restriction. Patients with only a diagnosis of stenosis or low back pain were excluded. Subjects were grouped by T1 Spino Pelvic inclination (T1SPi): sagittal forward (FW, > 0.6degree), neutral (NE, -6.6degree to 0.6degree) and backward (BW,<-6.6degree). OUTCOME MEASURES: T1SPi, Pelvic Shift (P.Shift), sagittal vertical axis (SVA), pelvic tilt (PT), lumbar lordosis (LL), "pelvic incidence minus lumbar lordosis" (PI-LL), TK (T1T12 kyphosis), T9SPi (T9 spinopelvic inclination), Sacro Femoral Angle (SFA), Knee Angle, Ankle Angle, chin brow vertical angle, and ODI (Oswestry Disability Index). METHODS: Pelvic translation was quantified by Pelvic Shift (the sagittal offset between the postero-superior corner of the sacrum and the anterior cortex of distal tibia). SPP were measured such as: SVA, PT, PI-LL, TK, T9SPi. Hip extension was measured using the SFA (angle between a line from middle of sacral endplate to bicoxo femoral axis and the femoral mechanical axis), Knee Angle (KA, angle of knee flexion), and Ankle Angle (AA, between tibial axis and vertical reference line) were positive in case of flexion. CBVA (chin brow vertical angle, between the chin-brow line and the ver!

BACKGROUND CONTEXT: Adult spinal deformity (ASD) surgery is known for its high complication rate. The incidence of radiographic and implant-related complications in the context of ASD surgery, and risk factors for its development has not been well defined. PURPOSE: This study examines the incidence of radiographic and implant- related complications in ASD surgery and their effect on the rate of reoperation. It also identifies risk factors for the development of radiographic and implant-related complications, and examines their impact on HRQOL. STUDY DESIGN/SETTING: Multicenter, prospective, consecutive case series. PATIENT SAMPLE: 245 surgical ASD patients. OUTCOME MEASURES: Radiographic and implant related complications, ODI, SF-36, and SRS questionnaires. METHODS: A multicenter prospective database of surgical ASD patients was reviewed. Patients with 2-yr follow-up were included. Radiographic and implant-related complications included: implant prominence, breakage, loosening, malposition or dislodgement, proximal / distal junctional kyphosis, pseudoarhrosis, fracture, and imbalance. HRQOL were measured using the ODI, SF-36, and SRS. Univariate testing was performed as appropriate. Multivariate logistic regression modeling was used to determine independent predictors of radiographic and implant related complications. Multivariate repeated measures mixed models were used to examine HRQOL, accounting for confounders. RESULTS: 246 patients met inclusion criteria. The incidence of radiographic and implant-related complications was 31.7%. 52.6% of those patients required reoperation. Rod breakage accounted for 47% of the implant- related complications, and proximal junctional kyphosis (PJK) accounted for 54.5% of radiographic complication Univariate analysis identified the following potential risk factors for radiographic and implant-related complications: weight (p=0.012), ASA (p=0.004), revision setting (p=0.026), stopping the fusion in the lower vs the upper thoracic spine (p=0.005), Schwab PT m!

BACKGROUND CONTEXT: Targets for adult spinal deformity (ASD) correction have been proposed including SVA<5cm, PT<20 deg, PI-LL less than 9. A novel radiographic parameter of sagittal alignment, the TPA, has been proposed with a postoperative target of less than 15degree. TPA simultaneously accounts for both truncal inclination and pelvic retroversion and does not vary based on the extent of pelvic retroversion or patient support in standing. Published alignment targets are based on broad age ranges of adults using baseline HRQOL and radiographic data. There are few studies correlating radiographic measures with preoperative and postoperative HRQOL in the elderly with spinal deformity to determine the applicability of such proposed targets. PURPOSE: To investigate preoperative and postoperative alignment parameters and HRQOL to determine the validity of targets of correction among elderly and middle-aged patients. STUDY DESIGN/SETTING: Multicenter, prospective database. PATIENT SAMPLE: 407 patients with adult spinal deformity. OUTCOME MEASURES: Oswestry Disability Index (ODI), Scoliosis Research Society (SRS)-22, and Short-Form (SF)-36 Physical Component Score (PCS). METHODS: Multicenter, prospective, analysis of consecutive ASD patients. Inclusion criteria were, age > 18, and any of the following: scoliosis Cobb angle > 20 deg, SVA > 5 cm, thoracic kyphosis > 60 deg, and PT greater than 25 deg. Baseline and 2-yr follow-up radiographic and HRQOL outcomes were evaluated. RESULTS: A total of 403 ASD patients were included in the baseline analysis, and 231 in the 2-year analysis. The operative patients were subanalyzed by age: elderly (ED: > 65yo, n=67) and middle age (MA: 40-60yo, n=99). At 2-year postop, elderly patients were more poorly aligned by TPA (23degree vs 15degree), SVA (5.9 vs 4.4 cm), PT (25.3degree vs 19.6degree) and PI-LL (12.1degree vs 3.7degree) with all p<0.01. Utilizing linear regression analysis, alignment thresholds were identified in the elderly and MA corresponding to severe!

BACKGROUND CONTEXT: Multiple options exist for the surgical correction of adult spinal deformity. The choice of these surgical procedures is often based upon surgeon preference, patient profile and curve pattern. There remains little guidance for surgeons to determine which options will provide them with the appropriate correction. PURPOSE: Evaluate the curve correction, change in health related quality of life measures (HRQOL), and complications in deformity matched Posterior Interbody (PI) or Posterior Only (PO) surgical correction. STUDY DESIGN/SETTING: Multicenter, prospective, consecutive case/ control series. PATIENT SAMPLE: 56 ASD patients. OUTCOME MEASURES: Oswestry Disability Index (ODI), SF36, and SRS-22. METHODS: Prospective, multicenter database. Inclusion criteria age > 18, adult spinal deformity, no prior fusion surgery, > 4 levels fused, fusion to sacrum, complete radiographic and HRQOL outcomes, min 2-yr followup. Complications were defined as minor or major per previously published criteria. Health related quality of life measures were determined for each patient for baseline, one and two years. Posterior approaches were propensity matched for Posterior Interbody (PI) and Posterior Only (PO) based on baseline SVA, PI-LL mismatch and PT by using linear regression. RESULTS: 56 patients met inclusion criteria and were matched; PI (28) and PO (28). Baseline demographics were similar for age (65 vs 63), BMI, co-morbidity, SVA (73 vs 63mm), PT (23 vs 23), LL (34 vs 38) and PI-LL (18 vs 18); P > 0.05. Baseline HRQOL measures similar for both groups, except for SF-36 mental (45 vs 37; p=0.03), and SRS-appearance (2.4 vs 2.1; p=.04). At 1 and 2 years HRQL improved significantly for each group, with no difference between groups. Radiographic improvement, 1yr and 2yr measures were all similar. Total EBL was greater for PI (2823 vs 1782cc; p=.014), with similar OR time and hospital stay. More Smith-Peterson Ostotomies were performed in PI group (3.2 vs 1.9 per pt; p=.005), with similar rat!

BACKGROUND CONTEXT: Intraoperative neuromonitoring (IOM) of spinal cord and nerve root injury through somatosensory evoked potentials (SSEP), transcranial motor evoked potentials (TcMEP), spontaneous electromyography (sEMG), and triggered electromyography (tEMG) modalities is vital during spinal surgery. However, there are currently no practice guidelines or practice patterns for the utilization of unimodal or multimodal IOM (MIOM) for specific spinal surgeries. PURPOSE: This pilot study documents practice patterns of IOM for select spinal procedures. STUDY DESIGN/SETTING: Questionnaire survey. PATIENT SAMPLE: 22 fellowship-trained spine surgeons, both surgeons and neurosurgeons, were queried on use of IOM modality combination in various spine procedures. Surgical experience varied from three to 29 years, with an average of 14.4 years. OUTCOME MEASURES: Percentage of surgeons using IOM modality or MIOM combination was calculated for each procedure. METHODS: Spine surgeons at two hospitals were surveyed on practice patterns of use of intraoperative monitoring for three deformity procedures and 21 non-deformity procedures. RESULTS: Of the 18 (81%) responses received: 15 from orthopaedic surgeons and 3 from neurosurgeons. Deformity Surgery: For both cervical and thoracic deformity surgeries, all surgeons used at least SSEP+TcMEP. For cervical surgeries, 47% of surgeons additionally used sEMG while for thoracic 71% of surgeons additionally used sEMG+tEMG. Most surgeons (44%) used all four modalities for lumbar deformity surgery. Non-Deformity surgery: For patients having radiculopathy undergoing ACDF, SSEP alone was utilized by 29%. However, in patients undergoing ACDF with symptoms of myelopathy, most surgeons (31%) used SSEP+TcMEP with only 13% using SSEP only. Fourty-six percent of surgeons utilized SSEP+TcMEP+sEMG for cervical arthroplasty procedures. SSEP+ TcMEP+sEMG was most commonly used for posterior cervical laminoforaminotomy, posterior cervical laminectomy and posterior cervical laminect!