[Accuracy of proximal femur correction achieved with LCP paediatric hip plates].

PURPOSE OF THE STUDY The aim of the study was to evaluate, in comparison with the pre-operative planning, the accuracy of proximal femur correction achieved with the use of locking compression paediatric hip plates (LCP) in children and adolescents and to assess pre- and post-operative complications. MATERIAL AND METHODS A group of 52 patients in whom proximal femoral osteotomy using the LCP was performed on a total of 55 hips between September 2009 and February 2013 were retrospectively evaluated. The following diagnoses were treated: unstable hip in cerebral palsy, 18 operations; Legg-Calvé-Perthes disease, 10 operations; coxa vara of aetiology other than coxa vara adolescentium (CVA), eight operations; true CVA, six operations; femoral shortening by the Wagner method, six procedures; proximal femoral derotation osteotomy, four procedures; and post-traumatic pseudoarthrosis of the proximal femur, three operations. RESULTS Compared with the pre-operative plan, the average deviation of the colodiaphyseal angle was 5.2° (1° to 11°) in 18 unstable hips; 4.7° (1° to 10°) in 10 cases of Legg-Calvé-Perthes disease; 4.5° (3° to 6°) in eight hips with coxa vara of aetiology other than CVA; 6.5° (2° to 13°) in six CVA hips; 4.5° (1° to 10°) in six cases of femoral shortening; 3.5° (1° to 5°) in four derotation osteotomies; and 3.7° (0° to 6°) in three corrections of pseudoarthrosis. In one patient, osteosynthesis failed due to screws being pulled out from the proximal fragment; re-osteosynthesis was carried out using a conventional angled blade plate. DISCUSSION As in other international studies, our results confirmed a high accuracy of proximal femur correction with use of the LCP instrumentation. The reported higher time requirement for this technique seems to be related to the learning curve and, with more frequent use, will probably be comparable to the time needed for application of conventional hip angled plates. CONCLUSIONS The up-to-date LCP fixation system using the principle of angular stability for correction of the proximal femur in children is a clear advancement and its higher costs are certain to be outweighed by its higher accuracy and thus better results.