Uncertainty in the Relationship Between Sagittal Alignment and Patient-Reported Outcomes

Neurosurgery ◽  
2019 ◽  
Author(s):  
Peter D Angevine ◽  
David Bray ◽  
Michael Cloney ◽  
Hani Malone

Abstract BACKGROUND Previous studies have reported correlations and precise quantitative relationships between sagittal alignment and health-related quality-of-life (HRQOL) scores. These studies have not reported the extent of uncertainty in these relationships. OBJECTIVE To explore the uncertainty in the overall relationships between sagittal alignment and HRQOL and in the predictions of individual patient pain and disability. METHODS A retrospective analysis of all new adult patients with long-cassette radiographs and complete outcomes questionnaires presenting to the senior author from 2012 to 2014 was performed. Univariable maximum a posteriori linear regression analyses using Bayesian methods were performed. High-density probability intervals for mean regression relationships and for individual values were calculated using minimally informative prior distributions. RESULTS A total of 134 patients satisfied inclusion criteria and were included. For Oswestry Disability Index (ODI) vs pelvic incidence-lumbar lordosis (LL), the 90% high-density probability interval ranged from –0.04 to 0.23, indicating that both the magnitude and direction of the relationship were uncertain. For both ODI vs sagittal vertical axis and ODI vs LL, there was uncertainty in the magnitude of the slope. Wide regions of uncertainty were also seen for predicting individual patient scores. CONCLUSION We report the previously unpublished degree of uncertainty in the mean quantitative relationships between radiographic sagittal alignment and patient-reported outcomes and in individual patient outcomes scores. Based on these results, establishing treatment thresholds or predicting an individual's outcome is unreliable. Further research efforts should be focused on developing multilevel hierarchical models incorporating parameter uncertainty and heterogeneous effects.

2021 ◽  
Vol 29 (1) ◽  
pp. 230949902199011
Author(s):  
Weiqing Qian ◽  
Kenji Endo ◽  
Takato Aihara ◽  
Yasunobu Sawaji ◽  
Hidekazu Suzuki ◽  
...  

Background: Dropped head syndrome (DHS) can be divided into two types, the positive sagittal vertical axis (SVA) type and the negative SVA type. However, the cervical sagittal alignment of DHS including global sagittal spinal alignment and the typical cervical alignment of the types of DHS is still unclear. The purpose of this study was to clarify the character of cervical sagittal alignment of DHS and analyze the relationship between cervical sagittal alignment and global sagittal spinal alignment. Methods: The subjects were 35 DHS patients (10 men, 25 women, mean 71.1 years old). They were divided into two groups: negative DHS (N-DHS group, SVA < 0 mm) and positive DHS group (P-DHS group, SVA ≥ 0 mm). As control, 28 age-matched cervical spondylosis patients (CS, 21 men, 7 women, mean 67.4 years old) were analyzed. The following parameters were measured on lateral global-spine standing radiographs: cervical SVA (C2-C7SVA), O-C2A (O-C2 angle), C2 slope (C2S), C2-7A (C2-7 angle), T1 slope (T1S) and C7SVA. Results: The results of measurements of each of the averaged sagittal alignment parameters were (CS, P-DHS, N-DHS): C2-7SVA(26.2 mm, 47.3 mm, 44.5 mm), O-C2 angle (35.0°, 37.1°, 39.3°), C2S (16.5°, 31.4°, 33.8°), C2-7A (9.3°, 9.9°, −16.6°), T1S (22.9°, 39.7°, 25.7°), C7SVA (35.3 mm, 51.0 mm, −43.1 mm). C2-C7SVA and C2S were significantly larger in both types of DHS compared to CS. Comparing P-DHS with N-DHS, C2-C7A and T1S were significantly smaller in N-DHS. Conclusions: O-C2A did not differ significantly among CS, P-DHS and N-DHS. In DHS patients, C2-7SVA and C2S were significantly larger than those of CS regardless of the type of DHS. The typical cervical sagittal alignment of DHS was different between P-DHS and N-DHS. In P-DHS, C2-7A and T1S were larger than those in N-DHS and the imbalance of thoraco-lumbar alignment should be noted.


2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Kuan Wang ◽  
Zhen Deng ◽  
Zhengyan Li ◽  
Huihao Wang ◽  
Hongsheng Zhan

Introduction. This study investigated the relationship between the parameters related to the natural head position and cervical segmental angles and alignment of patients with neck pain. Material and Methods. The lateral radiographs of the cervical spine were collected from 103 patients and were used to retrospectively analyze the correlation between the natural head position, cervical local sagittal angles, and alignment. Sagittal measurements were as follows: cervical curvature classification, slope of McGregor’s line (McGS), local sagittal angles (C0–C2 angle, C2–C5 angle, C5–C7 angle, and C2–C7 angle), T1 slope, center of gravity of the head to sagittal vertical axis (CG–C7 SVA), and local sagittal alignment (C0–C2 SVA and C2–C7 SVA). Results. McGS was significantly correlated to C0–C2 angle (r=0.57), C0–C2 SVA (r=−0.53), C2–C7 SVA (r=−0.28), and CG–C7 SVA (r=−0.47). CG–C7 SVA was also significantly correlated to curvature type (r=0.27), C5–C7 angle (r=−0.37), and C2–C7 angle (r=−0.39). Conclusions. A backward shift with an extended head position may accompany a relatively normal curvature of the cervical spine. The effect of posture control in relieving abnormal mechanical state of the cervical spine needs to be further confirmed by biomechanical analysis.


2020 ◽  
Vol 14 (4) ◽  
pp. 495-501 ◽  
Author(s):  
Tatsuya Yasuda ◽  
Daisuke Togawa ◽  
Tomohiko Hasegawa ◽  
Yu Yamato ◽  
Sho Kobayashi ◽  
...  

Study Design: Large cohort study of volunteers.Purpose: The purpose of this study was to investigate the relationship between the severity of knee osteoarthritis, assessed using the Kellgren-Lawrence (KL) grading scale, and spinopelvic sagittal alignment in older adult volunteers.Overview of Literature: The relationship between spinopelvic alignment in the sagittal plane and knee osteoarthritis in the coronal plane is unclear.Methods: Volunteers over 50 years of age underwent radiographic analysis. Radiographic parameters including pelvic tilt (PT), pelvic incidence (PI), lumbar lordosis (LL), thoracic kyphosis, and sagittal vertical axis (SVA) were measured. The the three Scoliosis Research Society-Schwab sagittal modifiers (PT, SVA, PI–LL) were categorized and the KL grade was assessed. Differences in spinopelvic parameters and Oswestry Disability Index (ODI) scores among KL grades were evaluated.Results: A total of 396 volunteers (160 men, 236 women; mean age, 74.4 years) were analyzed. PI–LL and PT in KL4 were significantly higher compared to that in the other KL grades. However, there were no significant group differences in SVA. In women, but not in men, higher frequencies of the worst modifier grade (++) were observed for PI–LL and PT in the KL3 and KL4 groups compared to those for the other KL grades. In women, the ODI score in KL4 was worse compared to that in the other KL grades.Conclusions: Individuals over 50 years of age with severe knee osteoarthritis had poor lumbo-pelvic sagittal alignment. Moreover, the progression severity of knee osteoarthritis had more impact onstronger relationship with lumbo-pelvic malalignment and disability-related low back pain in women than in men.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Laura Scaramuzzo ◽  
Antonino Zagra ◽  
Giuseppe Barone ◽  
Stefano Muzzi ◽  
Leone Minoia ◽  
...  

AbstractAim of the study was to evaluate sagittal parameters modifications, with particular interest in thoracic kyphosis, in patients affected by adolescent idiopathic scoliosis (AIS) comparing hybrid and all-screws technique. From June 2010 to September 2018, 145 patients were enrolled. Evaluation included: Lenke classification, Risser scale, coronal Cobb angle, thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS). Patients were divided in two groups (1 all-screws and 2 hybrid); a further division, in both groups, was done considering preoperative TK values. Descriptive and inferential statistical analysis was conducted. 99 patients were in group 1, 46 in group 2 (mean follow-up 3.7 years). Patients with a normo-kyphotic profile developed a little variation in TK (Δ pre–post = 2.4° versus − 2.0° respectively). Hyper-kyphotic subgroups had a tendency of restoring a good sagittal alignment. Hypo-kyphotic subgroups, patients treated with all-screw implants developed a higher increase in TK mean Cobb angle (Δ pre–post = 10°) than the hybrid subgroup (Δ pre–post = 5.4°) (p = 0.01). All-screws group showed better results in restoring sagittal alignment in all subgroups compared to hybrid groups, especially in hypo-TK subgroup, with the important advantage to give better correction on coronal plane.


2021 ◽  
pp. 219256822198964
Author(s):  
Siyu Zhou ◽  
Zhuoran Sun ◽  
Wei Li ◽  
Da Zou ◽  
Weishi Li

Study Design: Cross-sectional study. Objective: To provide the age- and pelvic incidence-related variations of sagittal alignment in asymptomatic Chinese population. Methods: This study recruited asymptomatic adult subjects. All subjects undertook the standing whole spinal radiograph and the sagittal parameters were measured: sagittal vertical axis (SVA), T1 pelvic angle (TPA), lumbar lordosis (LL), thoracic kyphosis (TK), pelvic incidence (PI) and pelvic tilt (PT). All subjects were divided into young, middle aged and elderly groups, then each age group was further divided into 5 subgroups (very low, low, average, high and very high) based on PI values. The relations between PI, age and other parameters were evaluated. The differences in sagittal parameters of each PI subgroup were compared. Results: 546 subjects were included with an average age of 38.6 years (18 to 81). The number of subjects over 70 years and with very low PI was relatively small. The average of PI, TPA, PT and LL were 45.9° ± 8.4°, 6.4° ± 6.2°, 11.9° ± 6.6° and 49.2° ± 10.1°, respectively. SVA, TPA, TK and PT increased with age ( P < 0.05), while SVA, TPA, PT, PI-LL also increased with PI ( P < 0.05). LL, PT, TPA, PI-LL and LL-TK were different among the 5 PI subgroups ( P < 0.05). However, the values of LL in elderly subjects with high and very high PI were similar. Conclusion: The age- and PI-related variations in sagittal alignment of Chinese population were provided. The sagittal parameters were significantly influenced by age and PI. The individual pelvic morphology should be carefully considered during the assessment and restoration of sagittal balance.


2021 ◽  
pp. 219256822110325
Author(s):  
Athan G. Zavras ◽  
T. Barrett Sullivan ◽  
Navya Dandu ◽  
Howard S. An ◽  
Christopher J. DeWald ◽  
...  

Study Design: Retrospective cohort study. Objectives: The current evidence regarding how level of lumbar pedicle subtraction osteotomy (PSO) influences correction of sagittal alignment is limited. This study sought to investigate the relationship of lumbar level and segmental angular change (SAC) of PSO with the magnitude of global sagittal alignment correction. Methods: This study retrospectively evaluated 53 consecutive patients with adult spinal deformity who underwent lumbar PSO at a single institution. Radiographs were evaluated to quantify the effect of PSO on lumbar lordosis (LL), thoracic kyphosis (TK), sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI), T1-spinopelvic inclination (T1SPI), T1-pelvic alignment (TPA), and sagittal vertical axis (SVA). Results: Significant correlations were found between PSO SAC and the postoperative increase in LL ( r = 0.316, P = .021) and PT ( r = 0.352, P = .010), and a decrease in TPA ( r = −0.324, P = .018). PSO level significantly correlated with change in T1SPI ( r = −0.305, P = .026) and SVA ( r = −0.406, P = .002), with more caudal PSO corresponding to a greater correction in sagittal balance. On multivariate analysis, more caudal PSO level independently predicted a greater reduction in T1SPI (β = −3.138, P = .009) and SVA (β = −29.030, P = .001), while larger PSO SAC (β = −0.375, P = .045) and a greater number of fusion levels (β = −1.427, P = .036) predicted a greater reduction in TPA. Conclusion: This study identified a gain of approximately 3 degrees and 3 cm of correction for each level of PSO more caudal to L1. Additionally, a larger PSO SAC predicted greater improvement in TPA. While further investigation of these relationships is warranted, these findings may help guide preoperative PSO level selection.


2021 ◽  
pp. 1-9
Author(s):  
Xunyi Wang ◽  
Yun Zheng ◽  
Gang Li ◽  
Jingzhe Lu ◽  
Yan Yin

<b><i>Introduction:</i></b> Outcome assessment for hearing aids (HAs) is an essential part of HA fitting and validation. There is no consensus about the best or standard approach for evaluating HA outcomes. And, the relationship between objective and subjective measures is ambiguous. This study aimed to determine the outcomes after HA fitting, explore correlations between subjective benefit and acoustic gain improvement as well as objective audiologic tests, and investigate several variables that may improve patients’ perceived benefits. <b><i>Methods:</i></b> Eighty adults with bilateral symmetrical hearing loss using HAs for at least 1 month were included in this study. All subjects completed the pure tone average (PTA) threshold and word recognition score (WRS) tests in unaided and aided conditions. We also administered the Chinese version of International Outcome Inventory for Hearing Aids (IOI-HA), to measure participants’ subjective benefits. Objective HA benefit (acoustic gain improvement) was defined as the difference in thresholds or scores between aided and unaided conditions indicated with ΔPTA and ΔWRS. Thus, patients’ baseline hearing levels were taken into account. Correlations were assessed among objective audiologic tests (PTA and WRS), acoustic gain improvement (ΔPTA and ΔWRS), multiple potential factors, and IOI-HA overall scores. <b><i>Results:</i></b> PTA decreased significantly, but WRS did not increase when aided listening was compared to unaided listening. Negative correlations between PTAs and IOI-HA scores were significant but weak (<i>r</i> = −0.370 and <i>r</i> = −0.393, all <i>p</i> &#x3c; 0.05). Significant weak positive correlations were found between WRSs and IOI-HA (<i>r</i> = 0.386 and <i>r</i> = 0.309, all <i>p</i> &#x3c; 0.05). However, there was no correlation among ΔPTA, ΔWRS, and IOI-HA (<i>r</i> = 0.056 and <i>r</i> = −0.086, all <i>p</i> &#x3e; 0.05). Moreover, 2 nonaudiological factors (age and daily use time) were significantly correlated with IOI-HA (<i>r</i> = −0.269 and <i>r</i> = 0.242, all <i>p</i> &#x3c; 0.05). <b><i>Conclusions:</i></b> Correlations among objective audiologic tests, acoustic gain, and subjective patient-reported outcomes were weak or absent. Subjective questionnaires and objective tests do not reflect the same hearing capability. Therefore, it is advisable to evaluate both objective and subjective outcomes when analyzing HA benefits on a regular basis and pay equal attention to nonaudiological and audiological factors.


2018 ◽  
Vol 4 (2) ◽  
pp. 205521731877789 ◽  
Author(s):  
Devon S Conway ◽  
Maria Cecilia Vieira ◽  
Nicolas R Thompson ◽  
Kaila N Parker ◽  
Xiangyi Meng ◽  
...  

Background Adherence to multiple sclerosis (MS) disease-modifying therapy (DMT) is commonly assessed through patient reporting, but patient-reported adherence is rarely studied. Objective To determine rates of DMT adherence reported from patient to clinician, reasons for nonadherence, and relationships between adherence and outcomes. Methods We identified relapsing–remitting MS patients on DMT for ≥3 months. DMT adherence was defined as taking ≥80% of doses. Linear and logistic regression models were created used to determine the association of baseline adherence with several patient reported outcomes and the timed 25-foot walk at 6 months, 1 year, 2 years, and 3 years after the index visit. Results The analysis included 1148 patients, of whom 501 had data at 6 months, 544 at 1 year, 331 at 2 years, and 247 at 3 years. Baseline adherence was 94.9% and overall adherence was 93.1%. Forgetting was the most common reason for missed doses. In the adjusted models, adherence was not associated with the outcomes. Conclusions Higher than expected adherence and a lack of association between adherence and outcomes suggests patient reported adherence may not be reliable. Further research is needed to clarify the relationship between patient-reported adherence and relapses or new lesion formation.


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