Prospective radiographic and forceplate analysis in adult volunteers. Assess gravity line (GL) location and foot position regarding anatomic spinal structures to evaluate key correlations and age-related changes in balance. Global spinal balance is commonly assessed by the C7 plumbline. This radiographic parameter does not offer information on foot position or forces transmitted, and poor correlation with the true GL has been demonstrated. A total of 75 asymptomatic adult volunteers were equally distributed into three age groups. Full length, free-standing spine radiographs were obtained with simultaneous acquisition of GL and feet location (forceplate). GL and heels were projected on each radiograph to compute their distance from anatomic entities and to investigate correlations with radiologic parameters and age-related changes. In this study group, advancing age led to a significant increase in thoracic kyphosis. The plumbline from C7 shifted anteriorly with age. In the sagittal plane, the GL was anterior to the vertebral column for all groups. With age, the GL location regarding the heels remained constant, while the pelvis moved posteriorly toward the heels and underwent a small retroversion (increasing pelvic tilt). The acetabulum was the most reliable radiographic marker of the GL location. This quantitative study in volunteers reveals clear age-related changes in the spino-pelvic association and offers quantitative support to the "cone of economy" concept proposed by Dubousset. The pelvis can be seen as a regulator to help maintain a rather fixed GL-heel association with age-related changes in the spinal column. Further study in patients suffering from deformity can confirm the importance of radiographic-gravity line correlations and enhance our understanding of optimal balance.

Multicenter, prospective, consecutive clinical series. To establish and validate classification of scoliosis in the adult. Studies of adult scoliosis reveal the impact of radiographic parameters on self-assessed function: lumbar lordosis and frontal plane obliquity of lumbar vertebrae, not Cobb angle, correlate with pain scores. Deformity apex and intervertebral subluxations correlate with disability. A total of 947 adults with spinal deformity had radiographic analysis: frontal Cobb angle, deformity apex, lumbar lordosis, and intervertebral subluxation. Health assessment included Oswestry Disability Index and Scoliosis Research Society instrument. Deformity apex, lordosis (T12-S1), and intervertebral subluxation were used to classify patients. Outcomes measures and surgical rates were evaluated. Mean maximal coronal Cobb was 46 degrees and lumbar lordosis 46 degrees . Mean maximal intervertebral subluxation (frontal plane) was 4.2 mm (sagittal plane, 1.2 mm). In thoracolumbar/lumbar deformities, the loss of lordosis/higher subluxation was associated with lower Scoliosis Research Society pain/function and higher Oswestry Disability Index scores. Across the study group, lower apex combined with lower lordosis led to higher disability. Higher surgical rates with decreasing lumbar lordosis and higher intervertebral subluxation were detected. A clinical impact classification has been established based on radiographic markers of disability. The classification has shown correlation with self-reported disability as well as rates of operative treatment.

Prospective, multicenter. To determine if models for predicting outcome and complications in the setting of adult deformity surgery can be constructed. A classification of adult spinal deformity has been established. The latter categorizes patients radiographically and ties to disability as well as most likely treatment approach. Classification by radiographs alone is insufficient to guide treatment and models for predicting outcome are necessary to establish algorithms. This is a longitudinal study of adult patients with spinal deformity. All subjects were drawn from a prospective multicenter database. Baseline, 1-year and 2-year radiographic and health related quality of life measures were obtained (SRS, ODI, SF-12). Any peri- or postoperative complications were tabulated. Binary and logistic regressions were applied to create models of outcome and complications. Predictive models of reaching a minimal clinically important difference had an area under the ROC curve above 0.82 and correct classification from 75% to 81%. Development of a complication was correctly classified in 71% of cases. Patients most likely to reach threshold improvement through surgery: older, lower apex deformity, greater disability, higher deformity score by classification. Patients most likely to develop complications: high sagittal balance grade and fusion to sacrum. By applying the classification of adult deformity and considering baseline health status, models for predicting outcome can be established. Further work will refine these models and permit clinical validation. This effort will help establish reliable clinical models such that treatment algorithms can be established for the challenging patients suffering from adult spinal deformity.

Multicenter prospective consecutive clinical series. Investigate the interaction between the Adult Deformity Classification and treatment patterns, surgical strategies, surgery effectiveness, and complication rates. An Adult Deformity Classification has been established that applies radiographic parameters of disability. Preliminary intraobserver and interobserver analysis reveals excellent reliability of the classification. Outcomes studies have not been reported to date. A total of 784 adult patients with thoracolumbar or lumbar deformity underwent radiographic evaluation (full-length frontal/sagittal) as well as health assessment: Oswestry Disability Index, Scoliosis Research Society-22, and SF-12. Patients were subdivided by treatment and surgical strategies; 1 year (111 patients) and 2 year (45 patients) follow-up data were analyzed. Interaction between classification, treatment, surgical strategy, health assessment changes, and complications were analyzed. Classification modifiers (lordosis, subluxation, sagittal balance) were found to have significant variation (higher rates) in surgical care as the grade of the modifier increased. Classification differentiated patients by surgical approach and/or technique. Interaction between classification and baseline health assessment impacts both postoperative health scores and complication rates. This investigation appears to offer the first comprehensive analysis of classification, treatment, and outcomes in a large adult deformity patient group. Significant treatment patterns and outcomes are coming to light as is the impact of surgical strategy

Retrospective consecutive clinical review of 98 patients. To create a preliminary approach to a clinically important classification of scoliosis in adult patients. There is currently no accepted classification of scoliosis in adults. High prevalence rates of scoliosis in the elderly and recent studies of health impact support the need for a clinically relevant classification. A total of 98 adult patients with scoliosis with a 2-year minimum treatment/follow-up were included. Patients were classified into one of 3 types of deformity based on the degree of lordosis (L1–S1) and frontal plane endplate obliquity of L3 on standing radiographs: type I = lordosis >55°, L3 obliquity <15°; type II = lordosis 35°–55°, L3 obliquity 15°–25°; and type III = lordosis 25°. Curve patterns included thoracic, thoracolumbar, lumbar, thoracic, and lumbar (mean Cobb angle 30°, standard deviation 19°). Cobb angle revealed no correlation to visual analog pain score (VAS) or general health (36-Item Short-Form Health Survey). Significant correlation between endplate obliquity L3, L1–S1 lordosis and VAS was noted (P < 0.05). Mean pain scores of classified patients were: type I, VAS = 27.7; type II, VAS = 43.3; and type III, VAS = 47.1 (type I vs. III, P < 0.05). Surgical rates (failed minimum 3-month conservative care, including bracing, physical therapy, and pharmacological treatment) by group were: type I, 0%; type II, 9%; and type III, 22.7% (P = 0.002). A simple classification of adult scoliosis was developed based on frontal and sagittal plane standing radiographs. With increasing type (from I to III), self-reported pain and disability increased. This result was reflected in the treatment approach as well, with surgical rates increasing from types I to III. Further refinement is important to develop an all inclusive and sufficiently descriptive system.