Limb lengthening over a nail can safely reduce the duration of external fixation

Abstract

Background: Limb lengthening using Ilizarov external fixation is safe, but the consolidation phase tends to take too long. A method that can safely reduce the time spent in external fixation would help increase patient tolerance and comfort. We report our results of lengthening over nails (LON) method in which an interlocking nail was used along with an Ilizarov external fixator to reduce external fixation duration in limb lengthening. This is a retrospective study.

Materials and methods: Twenty-seven lengthening surgeries were done with the LON method in 23 patients with 22 tibiae and five femora during the last 12 years. Length gain ranged from 1.5 cm to a maximum of 9.8 cm with a mean of 4.6 cm. The mean modified Paley difficulty score was 7.6 points. Fourteen associated procedures were performed in these patients, including equinus contracture releases, supracondylar osteotomies, ilizarov hip reconstruction and ankle fusion. We had a 29% rate of complications which included one problem, three obstacles and four complications with no serious deep intramedullary infections. Our rate of complications compares favorably with series reported in the literature. External fixation duration was reduced significantly to a mean of 17.8 days per cm.

Conclusions: A combination of intramedullary nailing along with external fixation significantly reduces external fixation time while maintaining low rate of complications. Great care needs to be taken to prevent pin track infection and deep intramedullary sepsis.

Keywords: Consolidation time; intramedullary nails; lengthening over nails; limb lengthening.

Figure 1

(a) Preoperative AP and lateral X-rays of left thigh including hip and knee. (b) Lengthening performed over a modified Humerus nail 7.5 cm length achieved. External fixator was removed in 13 weeks. (c) AP X-ray of left thigh showing bone consolidation with nail in situ. (d) 22 year old male with 8 cm shortening due to growth arrest following childhood septic arthritis of the lower femoral physis. (e,f) Final clinical result showing limb alignment and knee range of motion

Figure 2

25 year old lady had 12 cm shortening of her femur due to growth arrest. (a) AP and lateral X-rays of thigh including hip and knee. (b) LON method with rapid bone formation lead to premature consolidation at 3 cm. (c,d) A repeat corticotomy was done with the nail in situ which allowed lengthening till 6 cm when a repeat premature consolidation did not allow equalization of limb lengths. Part of the problem was also with the low initial length of the nail which could not have permitted more length