High frequency distraction improves tissue adaptation during leg lengthening in humans

Abstract

The present study investigates the effect of distraction frequency on the development of tensile force in the tissues during lengthening. Two patients with bilateral Ilizarov leg lengthening underwent distraction with high frequency in one leg and low frequency in the other. The clinical situation represented a unique model for investigating the effect of distraction frequency, as each individual served as its own control. Both patients had double level lengthening. Distraction frequency at the proximal lengthening zone was 0.25 mm x 4 in the first leg and 1/1440 mm once every minute in the other. Total diurnal distraction at the proximal metaphysis was 1 mm in both legs. In addition, a distal metaphyseal distraction of 0.25 mm x 3 daily was performed on each leg. The tissue's mechanical response was monitored by measuring the tensile force at the proximal osteotomy. Both patients experienced a significant lower level of force during the high frequency lengthening. The lower level of force was concluded to be due to improved soft tissue adaptation, rather than reduced bone regeneration. Accordingly, high distraction frequency was considered favouiabk to low frequency, and is recommended in large lengthenings where high force levels are expected.

Bone fracture healing in mechanobiological modeling: A review of principles and methods

“…However, the reports on distraction and tension rate have been inconsistent. While some studies have shown that healing quality does not depend on distraction rate (Augat et al, 2001, Hente et al, 2004), others have data which indicate the opposite (Isaksson et al, 2007, Aarnes et al, 2002, Ilizarov, 1989). One possible explanation for this inconsistency, might be that the tissues and cells involved in bone healing are more sensitive to compression rather than tension.…”

Mechanosensitive mechanisms in transcriptional regulation

“…At the same time, sustained application of mechanical force can sometimes repair diseased tissues. For instance, in a process referred to as distraction osteogenesis, gradual traction on bones is used to enhance osteogenesis for the treatment of skeletal deformities in dogs and humans (Ilizarov, 1989a;Ilizarov, 1989b;Aarnes et al, 2002). Similarly, constant stretching of the intestines leads to an increase in intestinal length in rats (Park et al, 2004) and stretching induces regeneration and lengthening of the esophagus in human infants with esophageal atresia (Foker et al, 1997).…”

Bone regeneration during distraction osteogenesis: Mechano-regulation by shear strain and fluid velocity

“…The third is the consolidation phase, during which there is no distraction, which finally leads to bony union. The rate of bone formation during DO is directly related to the distraction rate (Ilizarov, 1989b;Li et al, 1999Li et al, , 2000, frequency (Aarnes et al, 2002;Ilizarov, 1989b;Mizuta et al, 2003) and the strain/stress generated in the distraction gap (Li et al, 1997(Li et al, , 1999. Meyer et al (2001a) showed that the magnitude of distraction-generated mechanical tension directly influenced the phenotypic differentiation of the cells within the distraction gap.…”