Faculty Bibliography

BACKGROUND CONTEXT: Numerous studies have reported the interplay between spinal deformity and pelvis compensatory mechanisms, but little data exist evaluating the contribution of lower extremity compensation (LE) to maintain upright posture. We hypothesis that hip, knee and ankle compensation is proportional to the severity of the spinal deformity and varies by demographics. PURPOSE: Evaluate the association between spinal alignment and lower limbs compensation. STUDY DESIGN/SETTING: Multicenter, prospective cohort. PATIENT SAMPLE: This study included 288 patients treated for complex adult spinal deformity (ASD) with full body images available. OUTCOME MEASURES: Pelvic retroversion (PT), hip extension (SFA), knee flexion (KA), ankle dorsiflexion (AA), pelvic translation (P.Shift) and patient reported outcomes (ODI, PROMIS and SRS-22).
METHOD(S): Surgical ASD patients were enrolled into a prospective study based on three criteria: deformity severity (PI-LL>25degree, TPA>30degree, SVA>15cm, TCobb>70degree or TLCobb>50degree), procedure complexity (>12 levels fused, 3CO or ACR) and/or age (>65 and >7 levels fused). Associations between lower extremity compensation (hip extension, knee flexion, and ankle dorsiflexion) and the magnitude of spinal deformity, patient demographics, patient frailty, and patient-reported outcomes (ODI, SRS, PROMIS-CAT) were assessed via regressions and partial correlations.
RESULT(S): A total of 288/329 patients met inclusion criteria (60+/-15yo, 70.5% female), had moderate to severe spinal deformity (PI-LL:15+/-24, TPA:24+/-14, SVA:65+/-69mm, lumbar Cobb:34+/-24), and reported high pain (PROMIS pain interference; PI=62.7+/-7.8) and reduced physical function (PROMIS physical function; PF=35.6+/-7.6). Lower extremity compensation included pelvic retroversion (PT:24.1+/- 11.8), hip extension (SFA: 203+/-10.5), knee flexion (KA:5.5+/- 9.6), ankle dorsiflexion (AA: 5.3+/-4.5), and posterior pelvic translation (P.Shift: 30+/-51mm). Overall, lower extremity compensation increased with age (all p <0.001), BMI and frailty (all p <0.001, except SFA). For a similar PT, women had greater hip extension than men (SFA: 206 vs 200, p <0.001), with less KA (3.6 vs. 10.1, p <0.001), AA, and P.Shift. Lower extremity compensation increased with PI (r=0.2-0.45, p <0.001), TPA (r=0.5-0.9, p <0.001) and correlated with PROMS (ODI:0.26 - 0.37, PROMIS PF: -0.28 - -0.39, SRS Acti.: -0.20 - -0.33). When controlling for deformity severity and PI, most associations between lower limbs compensation and PROMS were lost. However, P.Shift and SFA remained weakly correlated with physical scores (ODI and PROMIS PF).
CONCLUSION(S): The recruitment of LE compensation is overall proportional to the severity of adult spinal deformity, with different patterns observed between men and women. Patients achieved similar PT by recruiting different patterns of LE compensation. Hip extension and posterior pelvic translation are independently associated with impairment in patient-reported outcomes. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Evidence on long-term maintenance of health status in adult spinal deformity (ASD) patients who improve above MCID threshold (MCID+) at 2 years following surgery is limited. PURPOSE: This study aims to: (1) evaluate whether patients who reached MCID+ status at two years postoperatively will maintain MCID+ status at 5 years, (2) identify risk factors associated with maintaining MCID+ status, and (3) Assess whether maintaining MCID+ status at 5 years is associated with satisfaction with surgery. STUDY DESIGN/SETTING: Retrospective review. PATIENT SAMPLE: Patients who underwent adult spinal deformity (ASD) surgery with minimum 5-year follow-up who achieved 2-year MCID in ODI were identified. OUTCOME MEASURES: Maintenance of MCID+ status at 5 years for Oswestry Diability Index (ODI).
METHOD(S): Patients who maintained MCID+ status at 5 years and those who did not formed the comparison groups. Multivariable logistic regression, controlling for age, complications after two years and two-year alignment, was used to identify risk factors associated with the inability to maintain MCID+ status. In a separate multivariable logistic regression, whether maintaining MCID+ status was associated with 5-year surgical satisfaction was assessed.
RESULT(S): Of 633 eligible patients, 339 had 5-year data. Of 133 with both 2- and 5-year data, 70 who achieved 2-year MCID in ODI were included. 30% (21) failed to maintain MCID+ status at 5 years. Preoperatively, 33% (23) were narcotic users, 47% (33) were frail and mean surgical invasiveness was 96.6+/-36.02. On multivariable logistic regression, preoperative variables were assessed: CCI > 3 (OR 5.75; p=0.026), ASA grade > 2 (OR 5.25; p=0.015), anemia (OR 19.74; p=0.009), and cancer (OR 6.46; p=0.015) were associated with increased odds of failure to maintain MCID+ status at 5-year follow-up. Patients who failed to maintain MCID+ status at 5 years had a higher odds of being unsatisfied with the surgery (OR 15.66; p=0.001). Frailty and surgical invasiveness had no significant impact on MCID+ status at 5 years.
CONCLUSION(S): Preoperative comorbid conditions significantly impact patient's long-term ability to maintain the positive gains in health-related quality of life measures from the surgery. Surgeons should continue to monitor and treat the chronic conditions to ensure maintenance of long-term recovery. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Adult spinal deformity (ASD) patients undergoing surgery risk neurological decline following surgery. However, surgery may be the key in improving outcomes in patients starting with lower extremity motor deficits at baseline (BL). We aim to analyze the improvement in neurological outcomes of ASD patients undergoing spinal reconstruction with BL and 6-week postoperative lower extremity motor scores (LEMS). PURPOSE: The aim of this study is to analyze the improvement in neurological outcomes of adult patients undergoing deformity surgery with baseline abnormal LEMS. STUDY DESIGN/SETTING: Multicenter, prospective cohort. PATIENT SAMPLE: A total of 205 patients were included in the study. OUTCOME MEASURES: Patient and procedural factors that lead to the improvement in neurological outcomes of adult patients undergoing deformity surgery with baseline abnormalLEMS.
METHOD(S): ASD patients ages = 18 were prospectively studied from 2018-2021. All patients underwent an instrumented PSF with a few also having an ASF of the lumbar spine. Patients were dichotomized based on BL LEMS (NML = 50, ABML < 50). The ABNML group was then dichotomized based on whether LEMS improved overall from BL or experienced no change or declined by first postoperative follow-up (PO) and various factors were analyzed and compared using standard statistical tests.
RESULT(S): Of the 205 patients evaluated, 134 (65.4%) were NML and 71 were ABNML (34.3%) at BL. Among the 71 patients with ABML LEMS at BL, 49% (N=35) improved to NML levels, 21% (N=15) improved from BL levels but not to NML, 20% (N=14) remained the same, and 10% (N=7) declined further at 6week PO. Compared to ABNML patients with no change or a decline in LEMS at first PO, patients who improved overall (70%; N=50) had significantly more decompressions performed (86% vs 57%; p=0.0092), and had more PCOs performed intraoperatively (90% vs 62%, p=0.0074). There were no statistical differences between the groups in age, BL LEMS, BMI, total instrumented vertebrae (TIV), EBL, and OR time. Overall, the number of patients with NML LEMS at 6 weeks PO increased by 7.5% (65.4% to 70.2%; p<.0001).
CONCLUSION(S): Seventy percent of patients with ABML LEMS at BL improved their motor strength by the first PO visit, while 30% stayed the same or declined. ABNML patients who improved from BL had significantly more decompressions performed and, surprisingly, more PCOs performed. Interestingly, patient factors between the two groups demonstrated no statistical differences further highlighting that improvement may be influenced by the differences in surgical techniques. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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OBJECTIVE:Revision surgery is often necessary for adult spinal deformity (ASD) patients. Satisfaction with management is an important component of health-related quality of life. The authors hypothesized that patients who underwent multiple revision surgeries following ASD correction would exhibit lower self-reported satisfaction scores. METHODS:This was a retrospective cohort study of 668 patients who underwent ASD surgery and were eligible for a minimum 2-year follow-up. Visits were stratified by occurrence prior to the index surgery (period 0), after the index surgery only (period 1), after the first revision only (period 2), and after the second revision only (period 3). Patients were further stratified by prior spine surgery before their index surgery. Scoliosis Research Society-22 (SRS-22r) health-related quality-of-life satisfaction subscore and total satisfaction scores were evaluated at all periods using multiple linear regression and adjustment for age, sex, and Charlson Comorbidity Index. RESULTS:In total, 46.6% of the study patients had undergone prior spine surgery before their index surgery. The overall revision rate was 21.3%. Among patients with no spine surgery prior to the index surgery, SRS-22r satisfaction scores increased from period 0 to 1 (from 2.8 to 4.3, p < 0.0001), decreased after one revision from period 1 to 2 (4.3 to 3.9, p = 0.0004), and decreased further after a second revision from period 2 to 3 (3.9 to 3.3, p = 0.0437). Among patients with spine surgery prior to the index procedure, SRS-22r satisfaction increased from period 0 to 1 (2.8 to 4.2, p < 0.0001) and decreased from period 1 to 2 (4.2 to 3.8, p = 0.0011). No differences in follow-up time from last surgery were observed (all p > 0.3). Among patients with multiple revisions, 40% experienced rod fracture, 40% proximal junctional kyphosis, and 33% pseudarthrosis. CONCLUSIONS:Among patients undergoing ASD surgery, revision surgery is associated with decreased satisfaction, and multiple revisions are associated with additive detriment to satisfaction among patients initially undergoing primary surgery. These findings have direct implications for preoperative patient counseling and establishment of postoperative expectations.

STUDY DESIGN/METHODS:A retrospective review of operative patients at a single institution. OBJECTIVE:To validate a novel method of detecting pseudarthrosis on dynamic radiographs. SUMMARY OF BACKGROUND DATA/BACKGROUND:A common complication after anterior cervical discectomy and fusion is pseudarthrosis. A previously published method for detecting pseudarthrosis identifies a 1 mm difference in interspinous motion (ISM), which requires calibration of images and relies on anatomic landmarks difficult to visualize. An alternative is to use angles between spinous processes, which does not require calibration and relies on more visible landmarks. METHODS:ISM was measured on dynamic radiographs using the previously published linear method and new angular method. Angles were defined by lines from screw heads to dorsal points of spinous processes. Angular cutoff for fusion was calculated using a regression equation correlating linear and angular measures, based on the 1 mm linear cutoff. Pseudarthrosis was assessed with both cutoffs. Sensitivity, specificity, inter- and intra-reliability of angular and linear measures used post-operative CT as the reference. RESULTS:242 fused levels (81 allograft, 84 PEEK, 40 titanium, 37 standalone cages) were measured in 143 patients (mean age 52.0±11.5, 42%F). 36 patients (66 levels) had 1-year postoperative CTs; 13 patients (13 levels) had confirmed pseudarthrosis. Linear and angular measurements closely correlated (R=0.872), with 2.3° corresponding to 1 mm linear ISM. Potential pseudarthroses was found in 28.0% and 18.5% levels using linear and angular cutoffs, respectively. Linear cutoff had 85% sensitivity, 87% specificity; angular cutoff had 85% sensitivity, 96% specificity for detecting CT-validated pseudarthrosis. Interclass correlation coefficients were 0.974 and 0.986 (both P<0.001); intra-rater reliability averaged 0.953 and 0.974 (P<0.001 for all) for linear and angular methods, respectively. CONCLUSIONS:The angular measure for assessing potential pseudarthrosis is as sensitive as and more specific than published linear methods, has high inter-observer reliability, and can be used without image calibration.

OBJECTIVE:Adult cervical deformity (ACD) has high complication rates due to surgical complexity and patient frailty. Very few studies have focused on longer-term outcomes of operative ACD treatment. The objective of this study was to assess minimum 2-year outcomes and complications of ACD surgery. METHODS:A multicenter, prospective observational study was performed at 13 centers across the United States to evaluate surgical outcomes for ACD. Demographics, complications, radiographic parameters, and patient-reported outcome measures (PROMs; Neck Disability Index, modified Japanese Orthopaedic Association, EuroQol-5D [EQ-5D], and numeric rating scale [NRS] for neck and back pain) were evaluated, and analyses focused on patients with ≥ 2-year follow-up. RESULTS:Of 169 patients with ACD who were eligible for the study, 102 (60.4%) had a minimum 2-year follow-up (mean 3.4 years, range 2-8.1 years). The mean age at surgery was 62 years (SD 11 years). Surgical approaches included anterior-only (22.8%), posterior-only (39.6%), and combined (37.6%). PROMs significantly improved from baseline to last follow-up, including Neck Disability Index (from 47.3 to 33.0) and modified Japanese Orthopaedic Association score (from 12.0 to 12.8; for patients with baseline score ≤ 14), neck pain NRS (from 6.8 to 3.8), back pain NRS (from 5.5 to 4.8), EQ-5D score (from 0.74 to 0.78), and EQ-5D visual analog scale score (from 59.5 to 66.6) (all p ≤ 0.04). More than half of the patients (n = 58, 56.9%) had at least one complication, with the most common complications including dysphagia, distal junctional kyphosis, instrumentation failure, and cardiopulmonary events. The patients who did not achieve 2-year follow-up (n = 67) were similar to study patients based on baseline demographics, comorbidities, and PROMs. Over the course of follow-up, 23 of the total 169 enrolled patients were reported to have died. Notably, these represent all-cause mortalities during the course of follow-up. CONCLUSIONS:This multicenter, prospective analysis demonstrates that operative treatment for ACD provides significant improvement of health-related quality of life at a mean 3.4-year follow-up, despite high complication rates and a high rate of all-cause mortality that is reflective of the overall frailty of this patient population. To the authors' knowledge, this study represents the largest and most comprehensive prospective effort to date designed to assess the intermediate-term outcomes and complications of operative treatment for ACD.

STUDY DESIGN/METHODS:A single-center, retrospective review of prospectively collected data on patients who underwent single-level anterior cervical discectomy and fusions (ACDFs) between October 2014 and October 2019. OBJECTIVE:To investigate the effect of perioperative narcotic consumption and amount of narcotic prescribed at discharge on patient satisfaction with pain control after single-level ACDF. SUMMARY OF BACKGROUND DATA/BACKGROUND:Prior research has demonstrated that opioid prescription habits may be related to physician desire to produce superior patient satisfaction with pain control. METHODS:Patients with complete Press-Ganey Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) survey information were analyzed. Inpatient opioid prescriptions were recorded and converted to milligram morphine equivalents (MME) and tablets of 5 mg oxycodone. HCAHPS scores were converted to a Likert-type 5-point scale. RESULTS:A total of 47 patients met inclusion criteria for this study. Average age was 48.1±10.9 y. Average inpatient opioids prescribed was 102±106 MME. Average opioids prescribed at discharge was 437±342 MME. No statistically significant correlation was found between satisfaction with pain control and opioid consumption while in the hospital [r=-0.106, P=0.483]. Similarly, there was no statistically significant correlation between satisfaction with pain control and opioids prescribed upon discharge [r=-0.185, P=0.219]. No statistically significant correlation was found between date of surgery and inpatient MME consumption [r=-0.113, P=0.450]. Interestingly, more opioids were prescribed at discharge the earlier the date of surgery [r=-0.426, P=0.003]. For every additional month further along in the study period, the odds of a patient reporting a top box score for satisfaction with pain control increased by 5.5% [P=0.025]. CONCLUSION/CONCLUSIONS:Our study found no correlation between patient satisfaction with pain control and inpatient opioid dosage or outpatient prescription dosage after single-level ACDF. Moreover, satisfaction with pain control increased over time despite a decrease in MME prescribed at discharge. This suggests that factors other than narcotic consumption play a more important role in patient satisfaction with pain control. LEVEL OF EVIDENCE/METHODS:Level III.

STUDY DESIGN/METHODS:This was a retrospective review of a prospectively collected database. OBJECTIVE:The aim of this study was to delineate radiographic parameters that distinguish severe cervical spine deformity (CSD). SUMMARY OF BACKGROUND DATA/BACKGROUND:Our objective was to define parameters that distinguish severe CSD using a consensus approach combined with discriminant analysis as no system currently exists in the literature. METHODS:Twelve CSD surgeons reviewed preoperative x-rays from a CSD database. A consensus was reached for categorizing patients into a severe cervical deformity (sCD), non-severe cervical deformity (non-sCD), or an indeterminate cohort. Radiographic parameters were found including classic cervical and spinopelvic parameters in neutral/flexion/extension alignment. To perform our discriminant analysis, we selected for parameters that had a significant difference between the sCD and non-sCD groups using the Student t test. A discriminant function analysis was used to determine which variables discriminate between the sCD versus non-sCD. A stepwise analysis was performed to build a model of parameters to delineate sCD. RESULTS:A total of 146 patients with cervical deformity were reviewed (60.5±10.5 y; body mass index: 29.8 kg/m2; 61.3% female). There were 83 (56.8%) classified as sCD and 51 (34.9%) as non-sCD. The comparison analysis led to 16 radiographic parameters that were different between cohorts, and 5 parameters discriminated sCD and non-sCD. These parameters were cervical sagittal vertical axis, T1 slope, maximum focal kyphosis in extension, C2 slope in extension, and number of kyphotic levels in extension. The canonical coefficient of correlation was 0.689, demonstrating a strong association between our model and cervical deformity classification. The accuracy of classification was 87.0%, and cross-validation was 85.2% successful. CONCLUSIONS:More than one third of a series of CSD patients were not considered to have a sCD. Analysis of an initial 17 parameters showed that a subset of 5 parameters can discriminate between sCD versus non-sCD with 85% accuracy. Our study demonstrates that flexion/extension images are critical for defining severe CD.

OBJECTIVE:To assess whether surgical cervical deformity (CD) patients meet spinopelvic age-adjusted alignment targets, reciprocal, and lower limb compensation changes. STUDY DESIGN/METHODS:Retrospective review. METHODS:CD was defined as C2-C7 lordosis >10°, cervical sagittal vertical angle (cSVA) >4 cm, or T1 slope minus cervical lordosis (TS-CL) >20°. Inclusion criteria were age >18 years and undergoing surgical correction with complete baseline and postoperative imaging. Published formulas were used to create age-adjusted alignment target for pelvic tilt (PT), pelvic incidence and lumbar lordosis (PI-LL), sagittal vertical angle (SVA), and lumbar lordosis and thoracic kyphosis (LL-TK). Actual alignment was compared with age-adjusted ideal values. Patients who matched ±10-year thresholds for age-adjusted targets were compared with unmatched cases (under- or overcorrected). RESULTS:= 0.269). CONCLUSIONS:In response to worsening CD postoperatively, patients increased in TK and recruited less lower limb compensation. Almost 75% of CD patients did not meet previously established spinopelvic alignment goals, of whom a subset of patients were actually made worse off in these parameters following surgery. This finding raises the question of whether we should be looking at the entire spine when treating CD. LEVEL OF EVIDENCE: 3/METHODS/:

BACKGROUND:Persistent pelvic compensation following adult spinal deformity (ASD) corrective surgery may impair quality of life and result in persistent pathologic lower extremity compensation. Ideal age-specific alignment targets have been proposed to improve surgical outcomes, though it is unclear whether reaching these ideal targets reduces rates of pelvic nonresponse following surgery. Our aim was to assess the relationship between pelvic nonresponse, age-specific alignment, and lower-limb compensation following surgery for ASD. METHODS:Single-center retrospective cohort study. ASD patients were grouped: those who did not improve in Scoliosis Research Society-Schwab pelvic tilt (PT) modifier (pelvic nonresponders [PNR]), and those who improved (pelvic responders [PR]). Groups were propensity score matched for preoperative PT and assessed for differences in spinal and lower extremity alignment. Rates of pelvic nonresponse were compared across patient groups who were undercorrected, overcorrected, or matched age-specific postoperative alignment targets. RESULTS:< 0.05). CONCLUSIONS:For patients with moderate to severe baseline truncal inclination, more aggressive surgical correction relative to ideal age-specific PI-LL was associated with lower rates of pelvic nonresponse. Postoperative alignment targets may need to be adjusted to optimize alignment outcomes for patients with substantial preoperative sagittal deformity. CLINICAL RELEVANCE/CONCLUSIONS:These findings increase our understanding of the poor outcomes that occur despite ideal realignment. Surgical correction of severe global sagittal deformity should be prioritized to mitigate these occurrences. LEVEL OF EVIDENCE: 3/METHODS/: