Distribution of branches of deep and common fibular nerves to extensor hallucis longus and extensor digitorum longus muscles. Application to the treatment of their hypertonia

Abstract

The spastic hemiplegic patient often presents dystonia of extensor hallucis longus (EHL) and, more rarely, extensor digitorum longus (EDL). This dystonia is difficult to treat by tendon lengthening, because its primum movens is purely neurological without retraction musculo-tendinous. A hyponeurotisation by partial section of the branches of the common and deep fibular nerve(s) could be a therapeutic alternative to botulinum toxin injections. Its technique has never been described. Ten legs from formalin-preserved corpses were dissected. The number of branches to EHL and EDL, their level of emergence from the common and deep fibular nerves, and their entry point into the muscle have been measured from the lateral femoral-tibial articular space (LTF). There was always a common trunk to the EDL and the EHL, arisen on average at 10.3 cm (8.2–13.6) from the LTF line. Six times out of 10 in addition to this common one (3), two (2) or three (1) additional branches to the EDL, arisen between 4.6 and 12 cm downstream the LTF line. Six times out of 10 in addition to this common trunk existed one (4) or two (2) additional branches to the EHL, arisen between 13 and 26 cm downstream the LTF line. This first study allow establishing the surgical technique of the hyponeurotisation of muscles LEH and LEO. The first results are presented.