OUR EXPERIENCE OF LOWER LIMB LENGTHENING WITH THE INTRAMEDULLARY SKELETAL KINETIC DISTRACTOR (ISKD)

Abstract

Limb lengthening is described by means of external fixator in limb length discrepancy. Intramedullary distraction is a relatively new procedure undertaken infrequently. We present our initial results following the use of the ISKD for lower limb lengthening.

Methods: A retrospective review, over a three year period, revealed six patients (five femurs and one tibia) underwent lengthening by ISKD. Four of the femoral cases were secondary to trauma. The other femoral case and tibial case were secondary to congenital shortening.

All cases were male with mean age of 35 years (20 – 54 years). The mean total distraction was 42mm (10 – 65mm) and a mean daily distraction of 0.96mm/day (0.78 – 1.75mm). Mean time to full weight bearing was 12.5 weeks. The planned length of distraction was achieved in all patients undergoing femoral lengthening. Four of these patients regained full movement of the knee at 6 months and the other regained an arc of 5 – 105 degrees.

The tibial lengthening only achieved 28.5% of the desired length as a result of premature consolidation and poor patient compliance. There were no cases of infection, DVT, non-union or hardware failure. Three patients experienced no complications. One patient experienced premature consolidation and required repeat corticotomy. Two patients experienced inappropriate lengthening. One experienced distraction at the previous fracture site and as a result required 5 further operations and application Ilizarov frame. The other was as a result of a runaway nail achieving 56mm distraction in 32 days (1.75mm/day).

This review, although with small numbers, highlights that the ISKD is a satisfactory treatment for femoral lengthening although we experienced difficulties with tibial lengthening. Following our experience all patients require a CT scan preoperatively to confirm union at the fracture site. ISKD has been considered an option for femoral lengthening only.