Ensuring precision in lower limb deformity correction through a combination of temporary external fixation followed by internal fixation: Results of a retrospective study

BACKGROUND: It is important to plan preoperatively when contemplating internal fixation following deformity correction. Surgeons often find it difficult to retain the achieved correction till the end of internal fixation. To maintain precise correction we used hybrid technique which uses both external and internal fixation. The objective of the study was to evaluate the effectiveness of this hybrid technique in achieving and retaining desired correction. MATERIALS AND METHODS: In this retrospective study, we evaluated the magnitude of deformity with radiological parameters. We compared correction which was planned and correction which was achieved. The technique was used during surgery for corrective osteotomies. Before carrying out the osteotomy, rail fixator with two swivel clamps was applied. After osteotomy swivel clamps were loosened. Desired correction was achieved. While fixator held the fragments in corrected position, definitive internal fixation was carried out. External fixator was removed after completion of internal fixation. Position of mechanical axis ratio, mechanical lateral distal femoral angle and mechanical medial proximal tibial angle were measured before and 12 weeks after surgery. Student t-test was used to analyze the difference between correction which was planned and correction which was achieved. RESULTS: There was no statistical difference between the desired correction and the correction achieved. CONCLUSIONS: Temporary use of external fixator while correcting angular deformities of lower limb allows to achieve accurate correction.