Clinical value of a new radiographic shoulder parameter for adolescent idiopathic scoliosis patients

Objective To assess the clinical value of a new radiographic shoulder parameter （coracoid process outer clavicle difference， CPCD） for adolescent idiopathic scoliosis （AIS） patients. Methods Seventy AIS patients with Lenke 1 （n=39） and 2（n=31） curves admitted to our hospital from February 2012 to March 2013 were included in this study. All patients underwent total spinal posterior-anterior radiographs and posterior shoulder aesthetic photographs at a natural standing position. The radiographic shoulder parameters， including coracoid process outer clavicle difference （CPCD） which was defined by us， and coracoid process height （CPH）， shoulder height difference （SHD）， radiographic shoulder height （RSH）， clavicle difference （CD）， which were defined by previous authors， were measured on the X-ray films. The outer shoulder height （SHo） was measured on the posterior shoulder aesthetic photographs. Correlation analysis was made between radiographic shoulder parameters and SHo. Results CPCD showed the highest correlation coefficient with SHo， while the correlation coefficient between RSH， SHD， CD， CPH and SHo was smaller than that between CPCD and SHo. Conclusion The new parameter （CPCD） has higher correlation coefficient with SHo than all the previous parameters. It can more accurately reflect the shoulder appearance and it is more valuable than previous parameters to evaluate the shoulder balance.