Relation between tibia malalignment after tibia nailing and foot pressure pattern.

Purpose: Intramedullary (IM) nailing in tibia fractures has been reported to have the potential to cause coronal plane malalignment that can be detrimental to foot pressure distribution and gait characteristics. The purpose of this paper was to explore tibia malalignment after tibia nailing and its association with foot pressure distribution using pedobarographic analysis.

Methods: 42 patients aged 18-80 years who sustained a tibia shaft fracture and who were operated with IM nailing were divided into three groups based on the degree of post-operative coronal plane angulation of the tibia: valgus malalignment (> 5° lateral angulation), varus malalignment (> 5° medial angulation), and normal alignment (< 5° angulation) as was measured on long leg scanograms. The patient was assessed over dynamic pedobarography system, which calculates the parameters like forefoot/hindfoot peak pressure ratio and PSI (pronation-supination index). The control involved a comparison between the affected foot and the unaffected foot of same patient.

Results: Comparing the ratio of forefoot/hindfoot peak pressure and PSI of the three groups, using paired t tests, the mean scores reveal that even with tibial coronal plane malalignment of  < 10°, the overall position of the foot did not differ significantly (p value > 0.5). However, in some patients, the peak pressure distribution in the hindfoot region of the affected side was higher compared to the contralateral side, suggesting Calacaneal gait due to triceps surae injury after initial trauma.

Conclusion: There was no difference in the forefoot/hindfoot peak pressure ratio and PSI and the mean of pronation-supination index between valgus, varus, and normal ankle alignment.

Study design: A prospective, open-label, retrospective investigation.