An Experimental Attempt to Replace Muscle Function by Elastic Endoprostheses

Abstract

SUMMARY An experimental investigation was undertaken in order to study the possibilities of replacing muscular function by internal elastic devices. Thirteen rabbits were operated on and a stretched rubber band was mounted in their vertebral skeleton between the crista ilica and one of the lower thoracic vertebrae. A severe to moderate scoliosis resulted, which in three cases was followed up to 608 days. The scoliosis was of a permanent character, i.e. it remained more or less unchanged 116 or more days after the rubber was removed. No pathological reactions of the tissues were observed after one to one and a half years. In all the cases the rubber was isolated in a very thin capsule of connective tissue, lubricated by a small quantity of a highly viscous fluid. The elasticity of rubber samples either remaining in the body up to one and a half years or stored outside it at room temperature deteriorated approximately 50 per cent in both cases. A study of the mechanics of the steel springs showed that stainless- steel springs of a high quality (18–8) retain under optimum conditions their elasticity practically without limitations of time and action. It is the author's opinion that elastic internal devices constructed from steel springs encased in rubber can be successfully used as substitutes for paralysed muscles.