Augmented blade plate fixation of a varus derotation osteotomy of the proximal femur using a tension band

Femoral derotation osteotomy in children with cerebral palsy using the pediatric proximal femoral nail

We designed a pediatric proximal femoral nail (PPFN) to overcome fixation method-related complications when performing femoral derotation osteotomy in cerebral palsy patients. Preliminary results of cerebral palsy patients who underwent femoral derotation osteotomy fixed using PPFN to treat in-toeing were evaluated. Sixteen patients with a mean age of 10 years were included. Mean follow-up duration was 36 months. There was no significant difference in the follow-up neck-shaft angle and articulotrochanteric distance values (P = 0.2 and 0.3). PPFN provides stable fixation, early weight-bearing, reduces soft-tissue disruption while limiting the complications due to fixation technique.

The outcome of paediatric LCP hip plate use in children with and without neuromuscular disease

BACKGROUND

The relatively new paediatric LCP hip plate (Synthes GmBH Eimattstrasse 3 CH-4436 Oberdorff) is used in children, both with and without neuromuscular disease, for fixation of proximal femoral osteotomy for a variety of indications.

MATERIALS AND METHODS

We retrospectively reviewed the notes and radiographs of all those children who have had paediatric LCP device for the fixation of proximal femoral osteotomy and proximal femur fractures in our institution (Royal Manchester Children's Hospital), between October 2007 and July 2010, for their clinical progress, mobilization status, radiological healing and any complications.

RESULTS

Forty-three paediatric LCP hip plates were used in 40 patients (27 males and 13 females) for the fixation of 40 proximal femoral osteotomies and three proximal femur fractures. This included 13 children with underlying neuromuscular pathology and 27 children without neuromuscular disease. All osteotomies and fractures radiologically healed within 6 months [majority (n = 40) within 3 months]. There was no statistically significant difference (p = 0.45) in the neck shaft angle between the immediately post-operative and final X-rays after completion of bone healing. There were no implant-related complications both in patients with and without neuromuscular disease. No metalwork loosening was observed and no plate revisions were required. Three post-operative fractures occurred in patients with neuromuscular pathology treated with post-operative plaster immobilisation.

CONCLUSION

The paediatric LCP hip plate provides a stable and reliable fixation of the proximal femoral osteotomy performed for a variety of paediatric orthopaedic conditions.

Development and mechanical testing of a short intramedullary nail for fixation of femoral rotational osteotomy in cerebral palsy patients

Background

Rotational osteotomy is frequently indicated to correct excessive femoral anteversion in cerebral palsy patients. Angled blade plate is the standard fixation device used when performed in the proximal femur, but extensile exposure is required for plate accommodation. The authors developed a short locked intramedullary nail to be applied percutaneously in the fixation of femoral rotational osteotomies in children with cerebral palsy and evaluated its mechanical properties.

Methods

The study was divided into three stages. In the first part, a prototype was designed and made based on radiographic measurements of the femoral medullary canal of ten-year-old patients. In the second, synthetic femoral models based on rapid-prototyping of 3D reconstructed images of patients with cerebral palsy were obtained and were employed to adjust the nail prototype to the morphological changes observed in this disease. In the third, rotational osteotomies were simulated using synthetic femoral models stabilized by the nail and by the AO-ASIF fixed-angle blade plate. Mechanical testing was done comparing both devices in bending-compression and torsion.

Results

The authors observed proper adaptation of the nail to normal and morphologically altered femoral models, and during the simulated osteotomies. Stiffness in bending-compression was significantly higher in the group fixed by the plate (388.97 ± 57.25 N/mm) than in that fixed by the nail (268.26 ± 38.51 N/mm) as torsional relative stiffness was significantly higher in the group fixed by the plate (1.07 ± 0.36 Nm/°) than by the nail (0.35 ± 0.13 Nm/°).

Conclusions

Although the device presented adequate design and dimension to fit into the pediatric femur, mechanical tests indicated that the nail was less stable than the blade plate in bending-compression and torsion. This may be a beneficial property, and it can be attributed to the more flexible fixation found in intramedullary devices.