Rib hump deformity assessment using the rib index in adolescent idiopathic scoliotics treated with full screw or hybrid constructs: aetiological implications.

Although the pre- and post-operative RI correction was statistically significant within each group, this did not happen post-operatively between the two groups. It appears that the RHD correction is not different, no matter what the spinal construct type was used. Provided that the full screw construct is powerful, the post-operative derotation and RHD correction was expected to be better than when an hybrid construct is applied, which is not the case in this study. It is therefore implied that the RHD results more likely from the asymmetric rib growth rather than from vertebral rotation, as it has been widely believed up to now. In 2013 Lykissas et al, reported that costoplasty combined with pedicle screws and vertebral derotation significantly improved RH deformity as opposed to pedicle screws and vertebral derotation alone. Another interesting implication is that the spinal deformity is the result of the thoracic asymmetry, implication in line with the late Prof. John Sevastikoglou's (Sevastik's) thoracospinal concept.