One-Way Self-Expanding Growing Rod: A Monocentric Study on 20 Patients

Introduction Severe and progressive early-onset scoliosis in children can have serious repercussions on lung development and significantly reduce life expectancy. They present a major challenge to the surgeon, as growth must be preserved. Traditional growing rods and the need for repeated lengthening surgeries are associated with numerous complications and high psycho-socio-economic costs for the patient and family. This study aimed to evaluate the lengthening efficacy of the one-way self-expanding rod (OWSER). Methods This retrospective and prospective, monocentric, observational clinical study evaluates the efficacy of lengthening of the self-expanding rod on the growth of 20 children between 2018 and 2023. Questionnaires on quality of life (EOSQ24 or Early Onset Scoliosis Questionnaire), clinical and radiological data were collected preoperatively, then at six weeks, three months, and six months postoperatively, and then annually until the end of the child's growth. The primary endpoint was system and spinal lengthening. Secondary endpoints were maintenance of deformity (Cobb angle), assessment of satisfaction questionnaires (EOSQ24), and complications with revision surgery. Results The mean age of patients was 11.5 years, with a mean follow-up time of 32 months. Sixty-five percent (65%) had scoliosis of neuromuscular origin, and 25% of syndromic origin. The T1-T12 segment lengthened by an average of 46 mm between preop and last follow-up and 14.4mm between postop and last follow-up. The T1-S1 height averaged 302 mm preoperatively, 352.9 mm postoperatively, and 385 mm at the last follow-up, a significant increase of 83 mm between preop and last follow-up (p < 0.0001) and a significant increase of 32.1 mm between postop height and the last follow-up (p<0.05). A significant decrease in the mean Cobb angle of 25° was measured between preop and last follow-up. Fifty-five percent (55%) of cases required revision surgery. Conclusion This study shows a significant lengthening of the OWSER in 20 patients, as well as satisfactory maintenance of coronal curvature. A longer follow-up period is required to assess long-term evolution.