Poster nr:

46

Author : Miguel Angel Galbán, Roceli Villanueva, Adolfredo SantanaCentro Clínico Leopoldo Aguerrevere, Caracas, Venezuela

ALTERNATIVE TREATMENT IN PATIENTS WITH IDIOPATHIC INTERNAL TIBIAL TORSION BY

SUPRAMALLEOLAR DEROTATION OSTEOTOMY OF THE TIBIA FIXED WITH LOCKING PLATES AND

MINIMAL INCISIONS

The idiopathic internal tibial torsion is not common in normal children, but when it occurs can cause disturbances of the gait. Flexible flatfoot and Shortening of the Achilles tendon often accompany this deformity. In order to treat it, the supramalleolar osteotomy of the tibia has been proposed, with or without concomitant fibular osteotomy. The method of fixation has been described with cast, Kirschner wires, Steinmann pins, staples, intramedullary nails, dynamic compression plates and external fixation.

Methods: We evaluated 36 patients, 63 tibias with idiopathic internal tibial torsion treated from November 2008 to December 2012. The mean age at the time of surgery was 10.7 years (5 to 25). All osteotomies were fixed with 3.5 mm strait locked plates and 4 locking screws (2 proximal and 2 distal). We used three minimal incisions, one anterior for proximal screws, another lateral for distal screws, these two incisions of 3 centimeters, and a third antero-medial incision of 5 millimeters for the percutaneous osteotomy. The plates were placed under the peroneals muscles and over the periosteum. The osteotomy was done by a percutaneous incision 3 centimeters above the physis.

Results: 62% of the patients were male. 27 Patients presented bilateral deformity and 9 patients had unilateral tibial torsion. The average thigh-foot angle evaluated before surgery was -16º and after surgery the correction got an average of +10º. 27% among the legs that needed lengthening of the Achilles tendon and casting for three weeks. The remaining patients did not use any immobilization and were free to move. All patients were allowed to full weight bearing at three weeks and they started to walk with crutches. Bone healing was obtained in all patients in a mean period of seven weeks (5 to 12). The plates were removed in a period that ranges from 4 months to 24 months with an average of 10 months.

We did not found loosening of the screws. Two patients with severe internal rotational deformities needed osteotomy of the fibula, and the decision to do it was intraoperatively. Two patients (4 limbs) had drop foot and paraesthesia over the dorsum of the foot, which recovered totally in a period of 3 weeks, to avoid this, in the last 22 cases we performed routinely a fasciotomy of the anterior compartment, through the same incisions. Another complication we observed was the wound dehiscence in 8 patients, in all cases healed by second intention, and the dehiscences never reach more than 4mm.

Conclusions: The lateral approach with minimal incisions is a safe surgical procedure that allows good coverage of the plate and protects the periosteum of the tibia. Also the fixation is stable enough to allow the free movements of the whole limb and permit the weight bearing at 3 weeks. The use of cast was limited to the patients that underwent lengthening of the Achilles tendon. We did not found loss of the correction in the follow up.