DOS 2018

188 · DOS Abstracts Testing a new surgical principle of guided growth for correction of rotational deformity of long bones in childhood. Andreas Balslev-Clausen, Peter Buxbom, Christian Wong, Klaus Hindsø Dept. of Orthopaedics, Hvidovre Hospital; Dept of Orthopaedics, Herlev Hospital; Dept. of Orthopaedics, Rigshospitalet Background: Correction using osteotomies and plates or frames for angular and rotational deformities of the lower extremity are large surgical procedures with risk of complications, but they can be necessary for amending the subse- quent gait disturbances, pain and decreased function caused by the deformity. Guided growth are used for correcting angular deformities in the growing pedi- atric patients, but the technique have not been used for rotational deformities in humans. So far only animal studies have been published. Purpose / Aim of Study: To investigate, if derotation using guided growth is possible in the human pediatric population. Materials and Methods: Five children (9 bone segments) with symptomatic rotational deformities were included after informed consent in a prospective and consecutive cohort. Using intraoperative fluoroscopy, Pediplates® were inserted across the growth plate in a 45 degree (dg.) angle on both sides of either the femoral and/or tibial physes of the knee. RSA beads were inserted systematically, and patients were followed up every three months with radio- stereometric analysis. Findings / Results: At 9.3 months follow up, there was an avg. of 5.5 dg. of derotation (range 0-12 deg) and a longitudinal growth of 8.4 mm (range 2.8-13). However, the first two patients (4 segments) showed minimal derota- tion and growth after 6 months, whereas the later three patients (5 segments) showed an average rotation of 9.3 dg. and 9.4 mm of growth. Also, a rebound effect of 2.49 dg. was demonstrated in two children 9.9 months after plate. Conclusions: The principles of guided growth can be applied for rotational de- formity in growing children. In principle, this can be utilized to correct rotational deformities with minimal morbidity and discomfort. Exact plate placement of plates is crucial and a rebound effect is to be expected. 129.