Introduction: Tibial pilon acquired deformities are often a combination of axial deviation, translation, rotational defects and leg length discrepancy. Correction of deformity pattern with a percutaneous rectilinear supramalleolar osteotomy and an external fixation by Ilizarov apparatus aims to reduce misalignment progressively, simultaneously and mini-invasively.

Method: From 1994 to 2004, 29 patients have been treated for pilon tri-planar deformity of the leg. The mean age was 26 years (range 16 to 49 years), 15 were males and 14 females. Type and level of the deformity were determined by preoperational X-ray pictures. Two rings of Ilizarov apparatus are positioned in the segment of the limb proximal to the osteotomy: one at the level of the proximal tibial metaphysis and the other 3–4 cm further the osteotomy. A third ring is positioned at the level of the tibial pilon, parallel to the articular edge of the ankle. In order to maintain stability of the ankle, a half ring or horseshoe-shaped component should be placed on the calcaneus and metatarsals with opposing olive wires. The positions of the mobile joints between the rings will depend on the location of the correction axis. The closed metaphiseal osteotomy is performed in order to correct triplanar deformities in a progressive way, through angulations and translation in an oblique plane. The half ring on the foot allows maintaining the ankle distracted, which is necessary to reduce articular compression and to avoid soft tissue damages and muscular contractures in this region. Correction of translational deformities, axial deviation, and rotational deformities we performed in two stages. The axial deviation and translational deformity should be corrected in the first stage, and the rotational deformity is corrected during the second stage.

Results: In all cases we achieved correction of the angular or rotational deformities. Bleeding was never over 100 ml. We have not observed any soft tissue damages. Controlled weight-bearing was practiced in first day postoperatively, and the mean hospitalization time was 4 days. Time required to reach the correction was in a range of 3–6 weeks. In 20 patients the entire of the leg discrepancy was in a range of 1,5–6 cm. We reported no case of infection or non union. The devices have been removed after a mean time of 11 weeks (range 8–15 weeks).

Conclusion: Corrections of triplanar deformity of the pilon by the Ilizarov apparatus are progressive and mini–invasive. Also, it allows treating misalignment and lengthening by a single operation. The apparatus layout combining foot fixation and ankle distraction permits to correct soft tissues, secondary deformities, and finally a rapid weight bearing recovery.