Bone transport for lower limb bone defects: circular versus monolateral external fixators

Abstract

Objective To compare circular and monolateral external fixators used for bone transport in the treatment of lower limb bone defects. Methods From January 2011 to April 2013, 42 patients with lower limb bone defects were treated in our department. Monolateral external fixator was used for bone transport in 20 patients. They were 14 males and 6 females, with a mean age of 31.6 years (from 20 to 53 years). Ten cases had femoral defects and 10 tibial defects. Circular external fixator was used for bone transport in the other 22 patients. They were 13 males and 9 females, with a mean age of 33.6 years (from 16 to 56 years). Five cases had femoral defects and 17 tibial defects. Time for fracture union, complications, and Paley s criteria for bony and functional recovery were documented. Results All the patients were followed up for 6 to 38 months (mean, 20.3 months). Bony union as achieved between all the bone segments. There were no significant differences between the 2 groups in the bone union index (1.8±0.4 m/cm versus 1.6±0.3m/cm) (P > 0.05). By the Paley's criteria for bony recovery, 17 cases were excellent and 3 fine in the monolateral fixator group while 20 were excellent and 2 fine in the circular fixator group. By Paley's criteria for functional recovery, 17 cases were excellent and 3 fine in the monolateral fixator group while 16 were excellent and 6 fine in the circular fixator group. By the Paley's criteria, there were no significant differences between the 2 groups with regard to secondary, primary and real complications (P > 0.05). Conclusions Both circular and monolateral external fixators are effective in bone transport to treat lower limb bone defects. The monolateral fixator is more tolerable for patients with femoral defects. The circular fixator is more advantageous for patients with complex long shaft defects because it allows for deformity corrections during bone transport. Key words: External fixators; Bone lengthening; Postoperative complications; Ilizarov technique