Limited morbidity and possible radiographic benefit of C2

Background: The study aims to evaluate differences in alignment and clinical outcomes between surgical cervical deformity (CD) patients with a subaxial upper-most instrumented vertebra (UIV) and patients with a UIV at C2. Use of CD-corrective instrumentation in the subaxial cervical spine is considered risky due to narrow subaxial pedicles and vertebral artery anatomy. While C2 fixation provides increased stability, the literature lacks guidelines indicating extension of CD-corrective fusion from the subaxial spine to C2. Methods: Included: operative CD patients with baseline (BL) and 1-year postop (1Y) radiographic data, cervical UIV ≥ C2. Patients were grouped by UIV: C2 or subaxial (C3-C7) and propensity score matched (PSM) for BL cSVA. Mean comparison tests assessed differences in BL and 1Y patient-related, radiographic, and surgical data between UIV groups, and BL-1Y changes in alignment and clinical outcomes. Results: Following PSM, 31 C2 UIV and 31 subaxial UIV patients undergoing CD-corrective surgery were included. Groups did not differ in BL comorbidity burden (P=0.175) or cSVA (P=0.401). C2 patients were older (64 Conclusions: C2 UIV patients showed similar cervical range of motion and baseline to 1-year functional outcomes as patients with a subaxial UIV. C2 UIV patients also showed greater baseline to 1-year horizontal gaze improvement and had complication profiles similar to subaxial UIV patients, demonstrating the radiographic benefit and minimal functional loss associated with extending fusion constructs to C2. In the treatment of adult cervical deformities, extension of the reconstruction construct to the axis may allow for certain clinical benefits with less morbidity than previously acknowledged

Limited morbidity and possible radiographic benefit of C2 vs. subaxial cervical upper-most instrumented vertebrae.

BackgroundThe study aims to evaluate differences in alignment and clinical outcomes between surgical cervical deformity (CD) patients with a subaxial upper-most instrumented vertebra (UIV) and patients with a UIV at C2. Use of CD-corrective instrumentation in the subaxial cervical spine is considered risky due to narrow subaxial pedicles and vertebral artery anatomy. While C2 fixation provides increased stability, the literature lacks guidelines indicating extension of CD-corrective fusion from the subaxial spine to C2.MethodsIncluded: operative CD patients with baseline (BL) and 1-year postop (1Y) radiographic data, cervical UIV ≥ C2. Patients were grouped by UIV: C2 or subaxial (C3-C7) and propensity score matched (PSM) for BL cSVA. Mean comparison tests assessed differences in BL and 1Y patient-related, radiographic, and surgical data between UIV groups, and BL-1Y changes in alignment and clinical outcomes.ResultsFollowing PSM, 31 C2 UIV and 31 subaxial UIV patients undergoing CD-corrective surgery were included. Groups did not differ in BL comorbidity burden (P=0.175) or cSVA (P=0.401). C2 patients were older (64 vs. 58 yrs, P=0.010) and had longer fusions (9 vs. 6 levels, P=0.002). Overall, patients showed BL-1Y improvements in TS-CL (P<0.001), cSVA (P=0.005), McGS (P=0.004). Cervical flexibility was maintained at 1Y regardless of UIV, assessed by CL flexion (-0.2° vs. 6.0°, P=0.115) and extension (13.9° vs. 9.9°, P=0.366). While both subaxial and C2 patients showed BL-1Y improvements in McGS (both P<0.030), C2 patients improved to a larger degree (7.3° vs. 6.2°). Between UIV groups, there were no differences in BL-1Y changes in HRQLs, overall complication rates, or operative complication rates (all P>0.05).ConclusionsC2 UIV patients showed similar cervical range of motion and baseline to 1-year functional outcomes as patients with a subaxial UIV. C2 UIV patients also showed greater baseline to 1-year horizontal gaze improvement and had complication profiles similar to subaxial UIV patients, demonstrating the radiographic benefit and minimal functional loss associated with extending fusion constructs to C2. In the treatment of adult cervical deformities, extension of the reconstruction construct to the axis may allow for certain clinical benefits with less morbidity than previously acknowledged

Does Patient Frailty Status Influence Recovery Following Spinal Fusion for Adult Spinal Deformity?: An Analysis of Patients With 3-Year Follow-up.

STUDY DESIGN: Retrospective review of a prospective database. OBJECTIVE: The aim of this study was to evaluate postop clinical recovery among adult spinal deformity (ASD) patients between frailty states undergoing primary procedures SUMMARY OF BACKGROUND DATA.: Frailty severity may be an important determinant for impaired recovery after corrective surgery. METHODS: It included ASD patients with health-related quality of life (HRQLs) at baseline (BL), 1 year (1Y), and 3 years (3Y). Patients stratified by frailty by ASD-frailty index scale 0-1(no frailty:0.5 [SF]). Demographics, alignment, and SRS-Schwab modifiers were assessed with χ/paired t tests to compare HRQLs: Scoliosis Research Society 22-question Questionnaire (SRS-22), Numeric Rating Scale (NRS) Back/Leg Pain, Oswestry Disability Index (ODI). Area-under-the-curve (AUC) method generated normalized HRQL scores at baseline (BL) and f/u intervals (1Y, 3Y). AUC was calculated for each f/u, and total area was divided by cumulative f/u, generating one number describing recovery (Integrated Health State [IHS]). RESULTS: A total of 191 patients were included (59 years, 80% females). By frailty: 43.6% NF, 40.8% MF, 15.6% SF. SF patients were older (P = 0.003), \u3ebody mass index (P = 0.002). MF and SF were significantly (P \u3c 0.001) more malaligned at BL: pelvic tilt (NF: 21.6°; MF: 27.3°; SF: 22.1°), pelvic incidence and lumbar lordosis (7.4°, 21.2°, 19.7°), sagittal vertical axis (31 mm, 87 mm, 82 mm). By SRS-Schwab, NF were mostly minor (40%), and MF and SF markedly deformed (64%, 57%). Frailty groups exhibited BL to 3Y improvement in SRS-22, ODI, NRS Back/Leg (P \u3c 0.001). After HRQL normalization, SF had improvement in SRS-22 at year 1 and year 3 (P \u3c 0.001), and NRS Back at 1Y. 3Y IHS showed a significant difference in SRS-22 (NF: 1.2 vs. MF: 1.32 vs. SF: 1.69, P \u3c 0.001) and NRS Back Pain (NF: 0.52, MF: 0.66, SF: 0.6, P = 0.025) between frailty groups. SF had more complications (79%). SF/marked deformity had larger invasiveness score (112) compared to MF/moderate deformity (86.2). Controlling for baseline deformity and invasiveness, SF showed more improvement in SRS-22 IHS (NF: 1.21, MF: 1.32, SF: 1.66, P \u3c 0.001). CONCLUSION: Although all frailty groups exhibited improved postop disability/pain scores, SF patients recovered better in SRS-22 and NRS Back. Despite SF patients having more complications and larger invasiveness scores, they had overall better patient-reported outcomes, signifying that with frailty severity, patients have more room for improvement postop compared to BL quality of life. LEVEL OF EVIDENCE: 3

A Risk Benefit Analysis of Increasing Surgical Invasiveness Relative to Frailty Status in Adult Spinal Deformity Surgery.

STUDY DESIGN: Retrospective review of a prospectively enrolled multicenter Adult Spinal Deformity (ASD) database. OBJECTIVE: Investigate invasiveness and outcomes of ASD surgery by frailty state. SUMMARY OF BACKGROUND DATA: The ASD Invasiveness Index incorporates deformity-specific components to assess correction magnitude. Intersections of invasiveness, surgical outcomes, and frailty state are understudied. METHODS: ASD patients with baseline and 3-year (3Y) data were included. Logistic regression analyzed the relationship between increasing invasiveness and major complications or reoperations and meeting minimal clinically important differences (MCID) for health-related quality of life (HRQL) measures at 3Y. Decision tree analysis assessed invasiveness risk-benefit cut-off points, above which experiencing complications or reoperations and not reaching MCID were higher. Significance was set to p \u3c 0.05. RESULTS: Overall, 195/322 patients were included. Baseline demographics: age 59.9 ± 14.4, 75% female, BMI 27.8 ± 6.2, mean Charlson Comorbidity Index: 1.7 ± 1.7. Surgical information: 61% osteotomy, 52% decompression, 11.0 ± 4.1 levels fused. There were 98 not frail (NF), 65 frail (F), and 30 severely frail (SF) patients. Relationships were found between increasing invasiveness and experiencing a major complication or reoperation for the entire cohort and by frailty group (all p \u3c 0.05). Defining a favorable outcome as no major complications or reoperation and meeting MCID in any HRQL at 3Y established an invasiveness cut-off of 63.9. Patients below this threshold were 1.8[1.38-2.35] (p \u3c 0.001) times more likely to achieve favorable outcome. For NF patients, the cut-off was 79.3 (2.11[1.39-3.20] (p \u3c 0.001), 111 for F (2.62 [1.70-4.06] (p \u3c 0.001), and 53.3 for SF (2.35[0.78-7.13] (p = 0.13). CONCLUSIONS: Increasing invasiveness is associated with increased odds of major complications and reoperations. Risk-benefit cut-offs for successful outcomes were 79.3 for NF, 111 for F, and 53.3 for SF patients. Above these, increasing invasiveness has increasing risk of major complications or reoperations and not meeting MCID at 3Y.Level of Evidence: 3

Predictors of Superior Recovery Kinetics in Adult Cervical Deformity Correction: An Analysis Using a Novel Area Under the Curve Methodology.

STUDY DESIGN: Retrospective review of a prospective database. OBJECTIVE: Identify demographic, surgical, and radiographic factors that predict superior recovery kinetics following CD corrective surgery. SUMMARY OF BACKGROUND DATA: Analyses of cervical deformity (CD) corrective surgery use area-under-the-curve (AUC) to assess health-related quality of life (HRQL) metrics throughout recovery. METHODS: Outcome Measures: Baseline (BL) to 1-Year (1Y) HRQL (Neck Disability Index [NDI]). CD criteria: C2-7 Cobb angle\u3e10°, coronal Cobb angle\u3e10°, cSVA\u3e4 cm TS-CL\u3e10°, or CBVA\u3e25°. AUC normalization divided BL and postoperative outcomes by BL. Normalized scores(y-axis) were plotted against follow-up(x-axis). AUC was calculated and divided by cumulative follow-up length to determine overall, time-adjusted recovery (Integrated Health State [IHS]). IHS NDI was stratified by quartile, uppermost 25% being \u27Superior\u27 Recovery Kinetics (SRK) vs. \u27Normal\u27 Recovery Kinetics (NRK). BL demographic, clinical, and surgical information predicted SRK using generalized linear modeling. RESULTS: 98 patients included (62 ± 10yrs, 28 ± 6 kg/m2, 65%F, CCI:0.95), 6% smokers, 31% smoking history. Surgical approach: combined (33%), posterior (49%), anterior (18%). Posterior levels fused: 8.7, anterior: 3.6, EBL: 915.9ccs, operative time: 495 min. Ames BL classification: cSVA (53.2% minor deformity, 46.8% moderate), TS-CL (9.8% minor, 4.3% moderate, 85.9% marked), horizontal gaze (27.4% minor, 46.6% moderate, 26% marked). Relative to BL NDI (Mean: 47), normalized NDI decreased at 3-months (0.9 ± 0.5, p = 0.260) and 1Y (0.78 ± 0.41, p \u3c 0.001). NDI IHS correlated with age (p = 0.011), gender (p = 0.042), anterior approach (p = 0.042), posterior approach(p = 0.042). Greater BL PT (SRK:25.6°, NRK:17°, p = 0.002), PI-LL (SRK:8.4°, NRK:-2.8°, p = 0.009), and anterior approach (SRK:34.8%, NRK:13.3%; p = 0.020) correlated with SRK. 69.4% met MCID for NDI( CONCLUSIONS: Superior recovery kinetics following cervical deformity surgery was predicted with high accuracy using baseline patient reported (VAS EQ5D, swallow sleep, mJOA) and radiographic factors (PT, TK, T10-L2, T12-S1, L1-S1). Awareness of these factors can improve decision-making and reduce postoperative neck disability.Level of Evidence: 3

Cervical deformity patients with baseline hyperlordosis or hyperkyphosis differ in surgical treatment and radiographic outcomes.

IntroductionPatients with symptomatic cervical deformity (CD) requiring surgical correction often present with hyperkyphosis (HK), though patients with hyperlordotic curves may require surgery as well. Few studies have investigated differences in CD-corrective surgery with regards to HK and hyperlordosis (HL).Materials and methodsOperative CD patients (C2-C7 Cobb >10°, cervical lordosis [CL] >10°, cervical sagittal vertical axis [cSVA] >4 cm, chin-brow vertical angle >25°) with baseline (BL) and 1Y radiographic data. Patients were stratified based on BL C2-7 lordosis (CL) angle: those >1 standard deviation (SD) from the mean (-6.96° ±21.47°) were hyperlordotic (>14.51°) or hyperkyphotic (≤28.43°) depending on directionality. Patients within 1 SD were considered the control group.ResultsOne hundred and two surgical CD pts (61 years, 65%F, 30 kg/m2) with BL and 1Y radiographic data were included. Twenty pts met definitions for HK and 21 pts met definitions for HL. No differences in demographics or disability were noted. HK had higher estimated blood loss (EBL) with anterior approaches than HL but similar EBL with the posterior approach. Op-time did not differ between groups. Control, HL, and HK groups differed in BL TS-CL (36.6° vs. 22.5° vs. 60.7°, P < 0.001) and BL-sagittal vertical axis (SVA) (10.8 vs. 7.0 vs. -47.8 mm, P = 0.001). HL pts had less discectomies, less corpectomies, and similar osteotomy rates to HK. HL had × 3 revisions of HK and controls (28.6 vs. 10.0 vs. 9.2%, respectively, P = 0.046). At 1Y, HL pts had higher cSVA, and trended higher SVA and SS than HK. In terms of BL-upper cervical alignment, HK pts had higher McGregor's-slope (16.1° vs. -3.3°, P = 0.001) and C0-C2 Cobb (43.3° vs. 26.9°, P < 0.001), however postoperative differences in McGregor's slope and C0-C2 were not significant. HK drivers of deformity were primarily C (90%), whereas HL had primary computed tomography (38.1%), upper thoracic (23.8%), and C (14.3%) drivers.ConclusionsHyperlodotic patients trended higher revision rates with greater radiographic malalignment at 1Y postoperative, perhaps due to undercorrection compared to kyphotic etiologies

Redefining cervical spine deformity classification through novel cutoffs: An assessment of the relationship between radiographic parameters and functional neurological outcomes.

Purpose: The aim is to investigate the relationship between cervical parameters and the modified Japanese Orthopedic Association scale (mJOA). Materials and Methods: Surgical adult cervical deformity (CD) patients were included in this retrospective analysis. After determining data followed a parametric distribution through the Shapiro-Wilk Normality ( Results: A total of 123 CD patients were included (60.5 years, 65%F, 29.1 kg/m Conclusions: Collectively, these radiographic values can be utilized in refining existing classifications and developing collective understanding of severity and surgical targets in corrective surgery for adult CD

Increasing Cost Efficiency in Adult Spinal Deformity Surgery: Identifying Predictors of Lower Total Costs.

STUDY DESIGN: Retrospective study of a prospective multicenter database. OBJECTIVE: The purpose of this study was to identify predictors of lower total surgery costs at 3 years for Adult Spinal Deformity (ASD) patients. SUMMARY OF BACKGROUND DATA: ASD surgery involves complex deformity correction. METHODS: Inclusion criteria: surgical ASD (scoliosis≥20°, SVA≥5 cm, PT≥25°, or thoracic kyphosis ≥60°) patients \u3e18 years. Total costs for surgery were calculated using the PearlDiver database. Cost per quality adjusted life year was assessed. A Conditional Variable Importance Table used non-replacement sampling set of 20,000 Conditional Inference trees to identify top factors associated with lower cost surgery for low (LSVA), moderate (MSVA), and high (HSVA) SRS Schwab SVA grades. RESULTS: 316/322 ASD patients met inclusion criteria. At 3Y follow up, the potential cost of ASD surgery ranged from $57,606.88 to$116,312.54. The average costs of surgery at 3 years was found to be $72,947.87, with no significant difference in costs between deformity groups (p \u3e 0.05). There were 152 LSVA patients, 53 MSVA patients, and 111 HSVA patients. For all patients, the top predictors of lower costs were frailty scores1.5, baseline (BL) ODI \u3c50 \u3e(all p \u3c 0.05). For LSVA patients, no history of osteoporosis, SRS Activity scores \u3e1.5, age CONCLUSIONS: ASD surgery has the potential for improved cost efficiency, as costs ranged from$57,606.88 to $116,312.54. Predictors of lower costs included higher baseline SRS activity, decreased frailty, and not having depression. Additionally, predictors of lower costs were identified for different baseline deformity profiles, allowing for the optimization of cost efficiency for all patients.Level of Evidence: 3