Ankle Motion after External Fixation of Tibial Fractures

Abstract

Loss of ankle movement is a complication of severe tibial fractures. This can be exacerbated if the foot is allowed to drop into equinus, particularly when an external fixator is employed. The range of ankle motion following external fixation of tibial fractures as compared to the opposite normal ankle was studied in 40 of 55 patients treated over a ten-year period. Nine were excluded due to other causes of ankle stiffness, leaving 31 cases for analysis. The mean follow up was 2 years 7 months (range 1 year to 8 years 3 months), and union had occurred by a mean of 35 weeks (range 9–100 weeks). The mean loss of ankle movement was 8° of plantar-flexion and 12° of dorsiflexion (overall loss 20°), the difference between the two being highly significant (P> 0.001, t test). Loss of ankle motion closely paralleled the degree of soft tissue trauma, being 6° for closed fractures and 22° for open fractures (0.05 > P> 0.02). Ankle function is therefore at risk when a severe tibial fracture is treated by external fixation, and appropriate measures should be taken to preserve movement and prevent an equinus contracture.