RECOVERY OF MEDIAL GASTROCNEMIUS-MUSCLE GRAFTS IN RATS - IMPLICATIONSFOR THE PLANTAR FLEXOR GROUP

Medial gastrocnemius (MGN) muscles were grafted in 18 rats and evaluat ed at 60, 90, and 120 days after the operation. Our purpose was to inv estigate the degree of recovery of the vascularized MGN grafts and the entire plantar flexor muscle group. Compared with control values, mus cle mass and maximum force of MGN grafts were decreased by 33 and 38% at 60 days, 22 and 32% at 90 days, and 13 and 15% at 120 days. At 60 a nd 90 days, the deficits in maximum force for the entire plantar flexo r muscle group, including the graft, were 29 and 17%, respectively. No difference was observed at 120 days. At 60 days, the deficit in the t otal mass of the plantar flexor group was 14% compared with control va lues, but by 90 days no deficit was observed. The restoration of norma l plantar flexor group structure and function indicates that the degre e of recovery attained by MGN grafts, although not complete, was suffi cient to ensure that the performance of the total muscle group was not compromised.