Vertebral rotation in adolescent idiopathic scoliosis calculated by radiograph and back surface analysis-based methods: correlation between the Raimondi method and rasterstereography.

PURPOSE

The aim of the present research is to evaluate the relationship between an X-ray-based method (i.e. the Raimondi method) and rasterstereography in the evaluation of vertebral rotation (VR) in a sample of adolescent idiopathic scoliosis (AIS) patients.

METHODS

A total of 25 patients (9 males; mean age 14 ± 3 years; mean height 160.7 ± 11.9 cm; mean weight 52.4 ± 10.7 kg) were considered for the present analysis. The mean Cobb angle was 30° ± 9°. The evaluation of VR on radiographs was made using the Raimondi method regolo (Marrapese Editore--Demi S.r.1., Rome). Rasterstereography was performed by means of Formetric 4D(®) (Diers International GmbH, Schlangenbad, Germany). Correlations between rasterstereographic and radiographic measurement of VR were calculated, both for the whole sample and for thoracic and lumbar spinal segments considered separately, as well as for subgroups of patients with a Cobb angle <30° and ≥ 30° using Spearman's correlation coefficient by rank (r (s)).

RESULTS

When applied to the entire spine, measurement of VR by means of the two methods highlighted a significant correlation in the whole group (r = 0.52; p < 0.0001), as well as in the <30° Cobb (r = 0.47; p = 0.0001) and ≥ 30° Cobb (r = 0.42; p < 0.0001) subgroups. A significant correlation was found also when lumbar and thoracic VR were considered as separated groups (r = 0.30, p = 0.024 and r = 0.47, p = 0.002, respectively).

CONCLUSIONS

Rasterstereographic evaluation of VR shows a good correlation with the Raimondi method, thereby confirming the possibility to use this non-invasive method for deformity assessment in AIS patients.