Adult spinal deformity: a very heterogeneous population of patients with different needs

The purpose of this study was to analyze and demonstrate the heterogeneity in adult spinal deformity (ASD) populations by baseline health-related quality of life (HRQL) data.

ASD was defined as patients over 18 years of age with any of the following: coronal deformity >20°, sagittal vertical axis (SVA) >5 cm, pelvic tilt >25°, or thoracic kyphosis >60°. Three hundred fifty-two patients meeting the above definition of ASD were analyzed for measures of HRQL (Oswestry disability index [ODI], SRS-22 [Scoliosis Research Society-22], and SF-36 [Short form-36 health survey] questionnaires) at presentation. Age groups were defined as 18-40, 40-60, and >60 years. Deformity was analyzed as either degenerative (DS) or idiopathic (IS) (294 patients; 71 degenerative, 223 idiopathic).

There were significant differences between age groups--predominantly between the lower age group (18-40) and others--for all HRQL parameters except SRS-22 mental health and SF-36 mental component score. Similarly, HRQL measures for DS and IS deformities were significantly different. Regarding location of main curves, thoracolumbar/lumbar (TL/L) (70.2%) was dominant for the DS group and thoracic (55%) for the IS group. Mean age was 65 years for the DS group and 36 for the IS group, which were significantly different. Radiographic parameters were also significantly different between these groups, with IS patients having more coronal deformity and better sagittal balance.

ASD patients are very heterogeneous at presentation, depending on age and diagnosis. There is a distinct need to stratify ASD as early and late presentation ASD and/or by diagnosis. Patients with IS deformity may be very different from those with DS deformity, even at time of presentation. These differences must be taken into consideration in treatment of these patients, as well as for the analysis of the results of treatment.