A retrospective comparative study of corrective osteotomy for tibial deformities with the multiaxial correction fixator and the circular fixator.

PURPOSE

A multiaxial correction (MAC) fixator is a monolateral type of fixator that can correct multi-planer deformities. The purpose of this study is to compare the clinical outcome of correction for tibial deformities with the MAC fixator and the circular external fixators.

METHODS

We retrospectively reviewed consecutive patients reconstructed with the MAC fixator (MAC group) or circular external fixators (Ring group) due to the congenital diseases or residual conditions after treatment of trauma, infection, tumor, or limb lengthening between 2003 and 2016.

RESULTS

The 30 patients who had angular tibial deformity were included. In patients with tibia vara or lateral bowing, the average pre-operative mechanical medial proximal tibial angle (mMPTA) of the MAC group and the Ring group was significantly increased to 86.9 ± 3.5° in the MAC group and 88.0 ± 3.6° in the Ring group postoperatively. Medial bowing was also successfully corrected in both groups. Regarding the sagittal alignment, post-operative anatomical posterior proximal tibial angle (aPPTA) of the MAC group was deteriorated after coronal correction. The operative time was significantly shorter in the MAC group than the Ring group (p < 0.05).

CONCLUSION

The MAC fixator successfully corrected coronal deformities of the tibia with shorter operative time, but it has a risk of occurrence of the procurvatum deformity compared with circular external fixators. Paying attention to the sagittal alignment, the MAC fixator can be one of the treatment options for correction of the coronal tibial deformities.