Classification of spinopelvic balance in ambulatory adolescents and adults with cerebral palsy: a cross-sectional study

We aimed to determine the spinopelvic profile types of ambulatory adolescents and adults with diplegic CP, and their relationship with functional ability (Gross Motor Function Classification System [GMFCS]), pain, and previous orthopaedic treatments. We measured anatomical variables on radiographs from 77 individuals with CP (mean age, 28.4, SD, 11.9 years), GMFCS levels I-III. We applied a non-supervised hierarchical ascendant classification followed by k-medoids analysis to 5 key anatomical variables. We compared radiological and clinical variable values between the spinopelvic profiles identified. Three spinopelvic profiles emerged, according to whether the pelvis was anteverted (sacral slope ≥ 38°) or retroverted (< 38°) and whether this was concordant with the pelvic incidence (≥ 54° for anteversion and < 54° for retroversion). Most (61/77, 79%) participants had anteversion, concordant for only 28/61 (46%); 16/77 (21%) had retroversion, concordant for 14/16 (88%). More participants with concordant anteversion experienced pain than participants with discordant anteversion (P = 0.03). Rates of previous treatments did not differ between concordant and discordant anteversion. More participants with GMFCS level III had discordant anteversion than those with levels I-II (P = 0.02). Categorising the spinopelvic profile is the first step to understanding pain causes and proposing targeted interventions and/or rehabilitation programs.