Faculty Bibliography

BACKGROUND:Congenital abnormalities when present, according to VACTERL theory, occur nonrandomly with other congenital anomalies. This study estimates the prevalence of congenital spinal anomalies, and their concurrence with other systemic anomalies. METHODS:A retrospective cohort analysis on Health care Cost and Utilization Project's Kids Inpatient Database (KID), years 2000, 2003, 2006, 2009 was performed. ICD-9 coding identified congenital anomalies of the spine and other body systems. OUTCOME MEASURES/METHODS:Overall incidence of congenital spinal abnormalities in pediatric patients, and the concurrence of spinal anomaly diagnoses with other organ system anomalies. Frequencies of congenital spine anomalies were estimated using KID hospital-and-year-adjusted weights. Poisson distribution in contingency tables tabulated concurrence of other congenital anomalies, grouped by body system. RESULTS:Of 12,039,432 patients, rates per 100,000 cases were: 9.1 hemivertebra, 4.3 Klippel-Fiel, 56.3 Chiari malformation, 52.6 tethered cord, 83.4 spina bifida, 1.2 absence of vertebra, and 6.2 diastematomyelia. Diastematomyelia had the highest concurrence of other anomalies: 70.1% of diastematomyelia patients had at least one other congenital anomaly. Next, 63.2% of hemivertebra, and 35.2% of Klippel-Fiel patients had concurrent anomalies. Of the other systems deformities cooccuring, cardiac system had the highest concurrent incidence (6.5% overall). In light of VACTERL's definition of a patient being diagnosed with at least 3 VACTERL anomalies, hemivertebra patients had the highest cooccurrence of ≥3 anomalies (31.3%). With detailed analysis of hemivertebra patients, secundum ASD (14.49%), atresia of large intestine (10.2%), renal agenesis (7.43%) frequently cooccured. CONCLUSIONS:Congenital abnormalities of the spine are associated with serious systemic anomalies that may have delayed presentations. These patients continue to be at a very high, and maybe higher than previously thought, risk for comorbidities that can cause devastating perioperative complications if not detected preoperatively, and full MRI workups should be considered in all patients with spinal abnormalities. LEVEL OF EVIDENCE/METHODS:Level III.

BACKGROUND:Congenital scoliosis (CS) is associated with more rigid, complex deformities relative to adolescent idiopathic scoliosis (AIS) which theoretically increases surgical complications. Despite extensive literature studying AIS patients, few studies have been performed on CS patients. The purpose of this study was to evaluate complications associated with spinal fusions for CS and AIS. METHODS:A retrospective review of the Kid's Inpatient Database (KID) years 2000 to 2009 was performed. Inclusion: patients under 20 years with ICD-9 diagnosis codes for idiopathic scoliosis (IS-without concomitant congenital anomalies) and CS, undergoing spinal fusion from the KID years 2000 to 2009. Two analyses were performed according to age below 10 years and 10 years and above. Univariate analysis described differences in demographics, comorbidities, intraoperative complications, and clinical values between groups. Binary logistic regression controlling for age, sex, race, and invasiveness predicted complications risk in CS (odds ratios; 95% confidence interval). RESULTS:In total, 25,131 patients included (IS, n=22443; CS, n=2688). For patients under age 10, CS patients underwent 1 level shorter fusions (P<0.001), had fewer comorbidities (P<0.001), and sustained similar complication incidence. In the 10 and over age analysis, CS patients similarly had shorter fusions, but greater comorbidities, and significantly more complications (odds ratio, 1.6; confidence interval, 1.4-1.8). CONCLUSIONS:CS patients have higher in-hospital complication rates. With more comorbidities, these patients have increased risk of sustaining procedure-related complications such as shock, infection, and Adult Respiratory Distress Syndrome. These data help to counsel patients and their families before spinal fusion. LEVEL OF EVIDENCE/METHODS:Level III-retrospective review of a prospectively collected database.

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.
Copyright

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.
Copyright

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).
Copyright

BACKGROUND CONTEXT: Distal junctional kyphosis (DJK) is a relatively new surgical concept often defined in the literature as a change in DJK angle <-10. This cut-off (based on previously established cut-offs for PJK) may carry clinical significance for patient quality of life; however, findings are lacking in the literature. When associated with neurological sequelae or reoperation, DJK may play a more robust role in patient HRQLs. PURPOSE: To establish a clinically relevant definition of symptomatic DJK. STUDY DESIGN/SETTING: Retrospective review of a prospective CD surgery database. PATIENT SAMPLE: One hundred and two patients with cervical deformity. OUTCOME MEASURES: Demographics, HRQL metrics.
METHOD(S): A prospective database of operative CD patients was analyzed. Inclusion criteria were cervical kyphosis >10, cervical scoliosis >10, cSVA >4cm or CBVA >25. DJK angle (DJKA) was defined >10degree change in kyphosis between LIV and LIV-2 in addition to >10degree index angle. Pts with DJKA >10degree & 1) no reop due to DJK(DJF) & 2) no physician-reported neurological sequelae at any time-point up to 1yr were categorized as "mild DJK." Those with a DJKA >10degree in addition to 1) reop due to DJK(DJF) or 2) >1 new-onset neurological sequelae related to DJK (spinal cord deficit, gait disturbance, hyperreflexia, lower-limb spasticity) were categorized as "Symptomatic DJK." ANOVA explored differences in PROMs (NDI, mJOA, EQ5D, EQ5DVAS, NRS) at baseline (BL) up to 1yr follow-up. Multivariate logistic regression analyzed predictors of inferior HRQLs associated with DJK groups, specifically scoring beyond one standard deviation (SD) of the mean value of all DJK pts.
RESULT(S): One hundred and two CD patients were analyzed. Sixty-five pts had no DJK, 25 pts had mild DJK and 12 pts had symptomatic DJK. By 1 year, 6/12 pts had DJF, 6/12 pts had >1 DJK-related neurologic sequelae not present before surgery(20% corticospinal tract deficit, 20% spasticity, 20% gait impairment, 20% hyperreflexia) without DJF, and 2 pts had both. Symptomatic DJK pts had higher mean DJKA than mild DJK pts immediately postop (29.8degree vs 19.1degree, p=0.150). No differences in BL HRQLs were noted between groups, including NDI, mJOA, EQ5D, VAS, and NRS Back (all p>0.05). At 1yr, Symptomatic DJK pts had significantly higher disability (52.3 vs 28.7, p=0.006) and trended lower EQ5D scores (0.75 vs 0.81, p=0.059), higher NRS back pain (5.82 vs 4.06, p=0.119), lower VAS (56.4 vs71.7,p=0.084), and lower mJOA (14.2 vs 15.0,p=0.495) than their mild DJK counterparts. Controlling for age and gender, conditional forward regression analysis revealed symptomatic DJK to a strong predictor of NDI >1 SD of the mean compared to mild DJK pts (OR: 43.4 [2.8 - 668.1], p=0.007); that is, symptoDJK increased the odds of NDI>1SD by at least 2.8x in relation to the mild DJK cohort.
CONCLUSION(S): DJK associated with reoperation and/or neurologic sequelae was associated with inferior quality of life metrics over long-term follow-up. Our results demonstrate that Symptomatic DJK may not necessarily correlate to a greater measured DJK angle per se (ie, >20degree); instead, DJK with concurrent neuro findings or subsequent reop better predicts worsened disability compared to DJK alone. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: The operative treatment of adult spinal deformity (ASD) can be very technically challenging with high complication rates. Despite these challenges it is well established that patients ultimately benefit from such treatment. However the surgical outcomes for patients with severe sagittal deformity have not been reported. PURPOSE: To investigate whether patients with severe sagittal deformity have favorable outcomes following surgical correction. STUDY DESIGN/SETTING: Retrospective review of a prospective, multicenter adult spinal deformity (ASD) database. PATIENT SAMPLE: Inclusion criteria: operative patients with age >=18, SVA >=15cm, PI-LL >=30degree, and/or lumbar kyphosis >=5degree with minimum 2-yr follow-up. OUTCOME MEASURES: Health-related quality of life (HRQOL) scores included: Oswestry Disability Index (ODI), Short Form-36 (SF36), Scoliosis Research Society (SRS22), back/leg pain numerical rating scale (NRS) and minimum clinically important difference (MCID)/substantial clinical benefit (SCB) for pts eligible to meet them. Radiographic values included: max coronal cobb angle, coronal C7 plumb line, pelvic tilt (PT), mismatch between pelvic incidence and lumbar lordosis (PI-LL), thoracic kyphosis (TK), C7 sagittal vertical axis (SVA). Demographic, frailty, surgical, and complications data were also collected.
METHOD(S): Comparisons between 2-yr postop and baseline HRQOL/radiographic data were made. P<0.05 was considered significant.
RESULT(S): A total of 138 pts were included (54.3% Female, ave age 63.3+/-11.5yrs). Ave baseline frailty score was 4.1+/-1.4 indicating the pt to befrail. Ave OR time 386.2+/-136.5min, EBL 1829.8+/-1474.6cc. 71 (51.4%) of the pts had a prior fusion; 89.9% posterior fusion only, 9.4% combined anterior-posterior approach. Mean number posterior levels fused 11.5+/-4.1. 44.9% had a 3-column osteotomy and 68.8% had interbody fusion. All 2-yr postop radiographic parameters were significantly improved compared to baseline (p<0.05 for all) except coronal C7 plumb line (p>0.05). All 2-yr HRQOL measures were significantly improved compared to baseline (p<0.004 for all); 46.6-73.8% of pts met either MCID or SCB for all HRQOL; 74.6% of pts had at least 1 complication, 11.6% had 4 or more complications, 33.3% had at least 1 major complication, and 42 (30.4%) had a postop revision.
CONCLUSION(S): Pts with severe sagittal malalignment benefit from surgical correction at 2-yrs postop both radiographically and clinically despite having a high complication rate. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: Analysis of interactions spinal alignment metrics may uncover novel and powerful alignment parameters, similar to pelvic incidence minus lumbar lordosis (PI-LL). PURPOSE: This study utilized a data driven approach to hypothesis generation by testing all possible division interactions between a set of spinal alignment parameters. TPA divided by PI (TPA/PI) was identified and subsequently characterized. STUDY DESIGN/SETTING: Retrospective analysis of a multicenter, prospectively-defined, consecutive cohort of ASD patients. PATIENT SAMPLE: A total of 1,439 patients with baseline ODI were included for hypothesis generation; 666 patients had 2-year postoperative follow-up and were included for validation. OUTCOME MEASURES: The primary outcome measure was Oswestry Disability Index (ODI).
METHOD(S): All possible combinations of division interactions between baseline metrics were assessed with linear regression against baseline ODI. Further analyses also utilized linear regression.
RESULT(S): From 247 raw alignment metrics, 32,398 division interactions were considered in hypothesis generation. Low-cervical and high-thoracic pelvic angles divided by pelvic incidence accounted for 7 of the top 10 most significant interactions. Conceptually, the TPA/PI is a measure of the relative alignment of the line connecting T1 to the femoral head and the line perpendicular to the sacral end plate. Among the validation cohort, the mean TPA/PI was 0.41 (SD 0.24) at baseline and 0.30 at 2 years postoperatively (SD 0.18). Higher TPA/PI was linearly associated with worse ODI at baseline (beta 28.7 for TPA/PI 1 vs 0, p<0.0001), 1 year (beta 16.5, p<0.0001), and 2 years (beta 20.0, p<0.0001). Further, the change in ODI at 2 years from baseline was linearly associated with the change in TPA/PI (beta 9.5, p=0.0172). The optimal statistical cutpoints for TPA/PI discriminating patients based on ODI were 0.21 and 0.41, labeled as 0 (<0.21), + (0.21-0.41), and ++ (>=0.41). At baseline, patients in the 0 group exhibited lower ODI as compared to patients in the + (41.8 vs 32.0, p<0.0001) and ++ (50.7 vs 32.0, p<0.0001) groups. The R-squared for regression of ODI against categorical TPA/PI alone (0.154) was directionally higher than that for the Schwab modifiers (SVA: 0.138, PI-LL 0.111, PT 0.057).
CONCLUSION(S): This study utilized a data-driven approach for hypothesis generation and identified TPA/PI, the spinopelvic ratio (SPR), as a promising measure of sagittal spinal alignment among ASD patients. This value is strongly associated with the Schwab modifier classification system. Patients with SPR >=0.21 exhibited inferior HRQOL. The SPR classification accounted for a directionally greater proportion of variance in ODI as compared to the three Schwab modifiers. These results highlight the interaction between global sagittal alignment and adequate pelvic structural support. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: Several methodologies have been proposed to determine ideal adult spinal deformity (ASD) sagittal spinopelvic alignment, two of them being; (1) patient age adjusted alignment based on pelvic incidence-lumbar lordosis (PI-LL), and sagittal vertical alignment (SVA) and (2) global alignment and proportion (GAP) score (a calculator initially developed to assess proximal junctional kyhosis [PJK] risk). A recent study evaluating the ability of different methodologies to predict PJK highlighted GAP inability to effectively predict PJK outside the original GAP creation data set. PURPOSE: Investigate a novel methodology (comprehensive alignment planing, or CAP) that utilizes a hybrid approach to assess ASD alignment by combining age adjusted alignment thresholds with concurrent alignment parameters. STUDY DESIGN/SETTING: Retrospective review of a prospective ASD database. PATIENT SAMPLE: Surgically treated ASD patients minimum 2-year follow-up. OUTCOME MEASURES: Sagittal alignment, ODI, SF-36, SRS-22r, proximal junctional kyphosis/failure, CAP and GAP scores.
METHOD(S): Multicenter ASD database was evaluated for surgically treated ASD patients with (1) fusion with a minimum of 5 levels, (2) fusion to pelvis, and (3) minimum 2-year follow-up. The CAP scoring methodology was created by assigning numerical values to the difference between each patient's postoperative sagittal alignment and ideal alignment as defined by previously reported age generational norms for PI-LL, PT, and TPA. CAP score ranges from -3 (if a patient is under corrected for all 3 parameters by at least 10 years) to +9 (if a patient is overcorrected by at least 30 years in all 3 parameters). A cumulative CAP score -1 to +2 represents unity between patient postop alignment and age alignment targets, CAP<=-2 represents under-correction, and CAP>+2 represents overcorrection. Postoperatively, PJK severity was categorized as None, PJK (angle 10degree), Severe-PJK (28degree), and PJF (PJK treated surgically). Postop HRQOL and PJK severity between each GAP and CAP categories were evaluated.
RESULT(S): Four hundred and nine667 patients meeting inclusion criteria were evaluated. Preoperatively most of the patients had moderate to severe deformity per SRS-Schwab modifiers (PT: 26degree, PI-LL=20degree, and SVA=80 mm). At 2 years, mean CAP score increased from -0.8+/-2.4 to +0.8+/-2.9 (p<0.001); 24.5% of the patients were undercorrected, 38.3% overcorrected, and 37.5% matched their age-adjusted target. By comparison GAP analysis categorized 29.6% of the patients as proportional, 39.9% as moderate deformity, and 36.5% as severe deformity. Postoperatively, HRQOL differences between CAP groups included ODI (p=0.025), SF36 MCS (p=0.014), SRS Pain (p=0.029) and SRS Total (p=0.043), while GAP was unable to discern HROQOL differences between GAP categories. PJK occurred in 37.9% of patients, severe PJK in 9.8%, and PJF in 6.6%. CAP score increased as PJK worsened (CAP=0.63 for no PJK, 1.42 for PJK, 2.31 for severe PJK, and 3.5 for PJF, p<0.001), however GAP score was unable to identify severity of PJK.
CONCLUSION(S): Evaluation of a novel ASD alignment assessment tool (CAP) demonstrates improved ability to predict the occurrence and severity of PJK compared to previously reported tools. Additionally the CAP tool correlates well with postoperative patient outcomes including HRQOL. The CAP tool may aid ASD surgical planning via use of age-adjusted alignment parameters allowing surgeons to target a postoperative alignment that minimizes complications and optimize surgical outcomes. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: Patients with severe cervical deformity (CD) often have profound deficits in numerous activities of daily living. Association between health status and postoperative radiographic goals is difficult to quantify. PURPOSE: Investigate the radiographic characteristics of patients who achieved optimal HRQOLs following surgery for CD. STUDY DESIGN/SETTING: Retrospective review of prospective CD database. PATIENT SAMPLE: Forty adult CD patients (C2-C7 Cobb>10degree, CL>10degree, cSVA>4cm, or CBVA>25degree). OUTCOME MEASURES: Health-related-quality of life (HRQL) scores, radiographic alignment.
METHOD(S): Surgical patients with severe CD were isolated based upon a previously presented combination of preop cSVA, T1 slope, maximum focal kyphosis in extension, C2 slope in extension, and number of kyphotic levels in extension. Those with available preop and 1-year postop HRQL data were included. Based on previous study, patients were grouped into 3 distinct patterns of CD: focal deformity (FD), flatneck (FN=large TS-CL and lack of compensation), or cervicothoracic (CT). Postoperative outcomes were defined as "good" if a patient had >2 of the 3 following criteria (1) NDI <20 or meeting MCID, (2) mild myelopathy (mJOA>=13), and (3) NRS-Neck <=5 or improved by >2 points from baseline. Within each distinct deformity group, patients with good outcomes were compared to those with poor outcomes (ie, not meeting the criteria for good) for differences in demographics, HRQL scores, and alignment, via chi-squared or student's t-tests.
RESULT(S): Overall, 83/153 patients met the criteria of severe CD and 40 patients had complete 1-year follow-up of clinical/radiographic data. Patient breakdown by deformity pattern was as follows: CT (N=13), FN (N=17), and FD (N=17), with 7 patients meeting criteria for both FD and FN deformities. Within the FD cohort, maximal focal kyphosis (ie, kyphosis at one level) was better corrected in patients with a "good" outcome (p = 0.03). In the FN cohort, patients who went on to have "good" outcomes presented with worse horizontal gaze (McGregor slope 21degree vs 6degree, p=0.061) and cSVA (72 mm vs 60 mm, p=0.030). "Good" outcome FN patients showed significantly greater postop correction of horizontal gaze (-25degree vs -5degree, p = 0.031). In the CT cohort, patients with "good" outcomes had superior global alignment both pre- (SVA: -17 mm vs 108 mm, p <0.001) and postoperatively (50 mm vs 145 mm, p=0.001). CT patients with "good" outcomes also had better postop cervical alignment (cSVA 35 mm vs 49 mm, p=0.030), and less kyphotic segments during extension (p=0.011). In the FD cohort, there were no differences between "good" and "poor" outcomes patients in preoperative alignment; however, "good" outcome patients showed superior changes in postoperative focal kyphosis (-2degree vs 5degree, p=0.030). Within all three deformity pattern categories, there were no differences between "good" and "poor" outcome patients with respect to demographics or surgical parameters (levels fused, surgical approach, decompression, osteotomy, all p>0.050).
CONCLUSION(S): The results of this study highlight intraoperative goals for three distinct sagittal morphotypes of severe CD: cervicothoracic, flat neck, and focal deformity. Distinct deformity specific intraoperative goals include obtaining proper sagittal global/cervical alignment for cervicothoracic patients, correcting maximal focal kyphosis in focal deformity patients, and correcting horizontal gaze for flat neck patients. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright