Abstract
Introduction
Current treatments of rotational deformities of long bones in children are osteotomies and fixations.
In recent years, the use of guided growth for correction of rotational deformities has been reported in several pre-clinical and clinical studies. Various techniques have been used, and different adverse effects, like growth retardation and articular deformities, have been reported. We tested a novel plate concept intended for correction of rotational deformities of long bones by guided growth, with sliding screw holes to allow for longitudinal growth, in a porcine model.
Method
Twelve, 12-week-old female porcines were included in the study.
Surgery was performed on the left femur. The right femur was used as control. Plates were placed distally to induce external rotation, as longitudinal growth occurred.
CT-scans of the femurs were processed to 3-D models and used for measuring rotation.
Result
The plates rotated as intended in all 12 porcines. One porcine was excluded due to congenital deformity of the proximal part of the femurs. Two porcines had cut-out of the proximal screw on the lateral side, observed at the end of the intervention. These two porcines were included in the results.
We observed a Δrotation of 5.7° ± 2° in external direction (CI: 3.7°– 7.7°).
ΔFemur length was -0.4 cm [-0.7 cm – 0 cm] equal to 1.5% shortening of the operated femur.
No significant difference was observed in coronal or sagittal plane.
Conclusion
Significant external rotation was achieved with minimal effect on longitudinal growth.
While the use of guided growth for correction of rotational deformities is already being used clinically, it is still to be considered an experimental procedure with sparse evidence.
This study shows promising results for the feasibility of the method in a large animal model and is an important first step in validating the technique and detecting possible adverse effects, before future clinical studies.
