Cost-utility of revisions for cervical deformity correction warrants minimization of reoperations.

Background: Cervical deformity (CD) surgery has become increasingly more common and complex, which has also led to reoperations for complications such as distal junctional kyphosis (DJK). Cost-utility analysis has yet to be used to analyze CD revision surgery in relation to the cost-utility of primary CD surgeries. The aim of this study was to determine the cost-utility of revision surgery for CD correction. Methods: Retrospective review of a multicenter prospective CD database. CD was defined as at least one of the following: C2-C7 Cobb \u3e10°, cervical lordosis (CL) \u3e10°, cervical sagittal vertical axis (cSVA) \u3e4 cm, chin-brow vertical angle (CBVA) \u3e25°. Quality-adjusted life year (QALY) were calculated by EuroQol Five-Dimensions questionnaire (EQ-5D) and Neck Disability Index (NDI) mapped to SF-6D index and utilized a 3% discount rate to account for residual decline to life expectancy (men: 76.9 years, women: 81.6 years). Medicare reimbursement at 30 days assigned costs for index procedures (9+ level posterior fusion, 4-8 level posterior fusion with anterior fusion, 2-3 level posterior fusion with anterior fusion, 4-8 level anterior fusion) and revision fusions (2-3 level, 4-8 level, or 9+ level posterior refusion). Cost per QALY gained was calculated. Results: Eighty-nine CD patients were included (61.6 years, 65.2% female). CD correction for these patients involved a mean 7.7±3.7 levels fused, with 34% combined approach surgeries, 49% posterior-only and 17% anterior-only, 19.1% three-column osteotomy. Costs for index surgeries ranged from $20,001-55,205, with the average cost for this cohort of$44,318 and cost per QALY of $27,267. Eleven revision surgeries (mean levels fused 10.3) occurred up to 1-year, with an average cost of$41,510. Indications for revisions were DJK (5/11), neurologic impairment [4], infection [1], prominent/painful instrumentation [1]. Average QALYs gained was 1.62 per revision patient. Cost was $28,138 per QALY for reoperations. Conclusions: CD revisions had a cost of$28,138 per QALY, in addition to the $27,267 per QALY for primary CD surgeries. For primary CD patients, CD surgery has the potential to be cost effective, with the caveats that a patient livelihood extends long enough to have the benefits and durability of the surgery is maintained. Efforts in research and surgical technique development should emphasize minimization of reoperation causes just as DJK that significantly affect cost utility of these surgeries to bring cost-utility to an acceptable range

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

Development of a Modified Cervical Deformity Frailty Index: A Streamlined Clinical Tool for Preoperative Risk Stratification.

STUDY DESIGN: Retrospective review OBJECTIVE.: Develop a simplified frailty index for CD patients SUMMARY OF BACKGROUND DATA.: To improve preoperative risk stratification for surgical cervical deformity (CD) patients, a CD frailty index (CD-FI) incorporating 40 health deficits was developed. While novel, the CD-FI is clinically impractical due to the large number of factors needed for its calculation. To increase clinical utility, a simpler, modified CD-FI (mCD-FI) is necessary. METHODS: CD patients (C2-C7 Cobb\u3e10°, CL\u3e10°, cSVA\u3e4 cm, or CBVA\u3e25°) \u3e18yr with preoperative CD-FI component factors. Pearson bivariate correlation assessed relationships between component deficits of the CD-FI and overall CD-FI score. Top deficits contributing to CD-FI score were included in multiple stepwise regression models. Deficits from model with largest R were dichotomized, and the mean score of all deficits calculated, resulting in mCD-FI score from 0 to 1. Patients were stratified by mCD-FI: Not Frail (NF,0.5). Means comparison tests established correlations between frailty category and clinical outcomes. RESULTS: Included: 121 CD patients (61 ± 11yr, 60%F). Multiple stepwise regression models identified 15 deficits as responsible for 86% of the variation in CD-FI; these factors were used to construct the mCD-FI. Overall, mean mCD-FI was 0.31 ± 0.14. Breakdown of patients by mCD-FI category: NF: 47.9%, Frail: 46.3%, SF: 5.8%. Compared to NF and Frail, SF patients had the longest inpatient hospital stays (P = 0.042), as well as greater baseline neck pain (P = 0.033), inferior NDI scores (P CONCLUSIONS: Increased frailty, assessed by mCD-FI, correlated with increased length of stay, neck pain, and decreased health-related quality of life. Frail patients were at greater risk for infection, and severely frail patients had greater odds of mortality. This relationship between frailty and clinical outcomes suggests that mCD-FI offers clinical utility as a preoperative risk stratification tool. LEVEL OF EVIDENCE: 3

Konvergente und diskriminante Validität über die Zeit : Integration von Multitrait-Multimethod-Modellen (MTMM-Modellen) und der Latent-State-Trait-Theorie (LST-Theorie)

Ziel dieses Kapitels ist es, zu verdeutlichen, dass Merkmalsausprägungen von Individuen über die Zeit schwanken können, und dass somit auch die konvergente und diskriminante Validität verschiedener Methoden und Konstrukte zeitlichen Veränderungen unterworfen sind. Die Analyse konvergenter und diskriminanter Validität ist Basis jeder diagnostischen Entscheidung. Nur bei gesicherter Qualität der eingesetzten Verfahren können Indikationen für mögliche Interventionen zuverlässig getroffen werden. Besonders bei Kindern, die sich in einem Entwicklungsprozess befinden, aber auch bei Erwachsenen ist es notwendig, die zeitliche Stabilität der gefundenen Testscores zu untersuchen. Nur bei gegebener Stabilität der Messungen kann von einem stabilen Trait ausgegangen werden. Darüber hinaus ist es wichtig, zu analysieren, wie sich die konvergente Validität verschiedener Messmethoden über die Zeit entwickelt. Drei longitudinale multimethodale Modelle für mehrere Traits werden vorgestellt, die es erlauben, die Konvergenz verschiedener Methoden und die diskriminante Validität von Traits und States zu untersuchen. Die empirischen Anwendungen zeigen deutlich, dass implizite Annahmen über die Übereinstimmung verschiedener Methoden prinzipiell überprüft werden müssen.publishe