Early mobilization after sliding and Z-lengthening of heel cord : a preliminary experimental study in rabbits

Sliding lengthening and Z-lengthening techniques are widely used in heel cord lengthening. Even though most surgeons performing these procedures apply a short leg cast after surgery, their postoperative immobilization intervals vary from 3 to 7 weeks. Nather et al. showed that there was no need for immobilization after the musculotendinous lengthening of long, deep flexor tendons. In the present study, we aimed to show the healing process of heel cords lengthened by sliding and Z-plasty lengthening in rabbits that did not undergo any postoperative immobilization. We performed sliding lengthening in the right heel cords of the rabbits and Z-lengthening in the left heel cords. We compared these two techniques radiographically, biomechanically, and histopathologically. Even though the biomechanical study showed superior results in the sliding lengthening group on the 7th day, elongation of the tendons at both sites was seen radiographically. There was no statistically significant difference between the sites according to the biomechanical study done on the 28th day. We concluded that the ankle should be immobilized in the early healing phase and that both types of lengthening gain a similar level of strength by the 4th week.