Experimental observations on the effects of leg lengthening by the Wagner Method

A proximal tibial epiphysiodesis was successfully performed on the right hind legs of 23 young lambs, producing an average shortening of 12% of the total length of the tibia. A lengthener was attached to stainless steel pins which were then tapped into the shortened tibia prior to osteotomy. In 16 of the 23 animals it was possible to lengthen the shortened bone at a rate of 0.5 mm twice daily until the discrepancy was corrected. The gait was normal in most of the animals, all had full knee motion with no thigh atrophy, and 16 had limited hock (ankle) joint motion. Lengthening of the tibia by more than 11% consistently produced muscle changes in the leg and cartilage damage in the hock (ankle) joint. Any malalignment of the tibial fragments during lengthening intensified these changes.