Effects of Tenotomy on the Growth of Muscle and its Tendon

Abstract

THE immediate changes which occur in an adult muscle after section of its tendon have been summarized by Sunderland and Lavarack¹. Regeneration of an experimentally transected tendon occurs within 2–3 weeks^2,3 even where the muscle has been denervated previously⁴, and some muscle function is thus soon restored. Because the dysfunction appears to be only temporary, the possibility of some permanent effect on the muscle has been overlooked even though it has been shown^5,6 that, six weeks after tenotomy, the repaired tendon is longer while its muscle remains both shorter and lighter than the control. Therefore, in an investigation of the relationship between the strength of a muscle and the collagen content of its tendon⁷, the operation of tenotomy was included to modify the normal muscle-tendon relationship during growth. The tendon of tibialis anterior was transected just distal to the muscle-tendon junction in the right hind-limb of five 4-week-old rabbits, the other limb serving as a control. The stumps were not sutured but allowed to retract. The animals made an uneventful recovery and were killed when 180 days old. No adhesions were present at the site of tendon repair.