Abstract
Aims: Muscle fat degeneration and fibrosis following long time denervation is today the main cause of poor functional recovery after peripheral nerve surgery especially for reconstruction of proximally located lesions of median and ulnar nerves such as those at brachial plexus level. External electro-stimulation is actually one possible way to avoid muscular atrophy and degeneration and is frequently used in the post-operative of patients with neurological palsy. A new approach that has been proposed to prevent denervation-related muscle atrophy is sensory protection performed by direct neurotization of a denervated muscle with a branch of a sensitive nerve passing nearby. The aim of this study was to study the effectiveness of sensory protection on denervated muscles as a technique to avoid their atrophic process.
Methods: In four groups of rats (A,B,C and D), the median nerves were transected at right and left forearm. In group A,B and C, denervated muscles were “reinnervated” with a sensory nerve (sensory protection). Animals of group A was sacrificed after six months for a morphologic study of muscles. Animals of groups B and C were reinnervated after six months either keeping sensory protection (group B) or removing it (group C) and sacrificed after one year. Group D (without sensory protection) was reinnervated after six months and sacrificed after one year (control group). Muscle histology was performed on all samples. Functional comparison of different group was perfor-mend by means of the grasping test.
Results: Histological analysis showed that sensory protection led to a better muscular trophism in all experimental groups. Also the functional testing showed better performances in sensory protected animals and especially in group C (de-protected before re-innervation) compared with group B (not de-protected before re-innervation) and D (control).
Conclusions: Initial data analisys obtained in this study showed that sensory protection is effective in reducing denervation-related muscle atrophy. De-protection of the muscle before its reinnervation is also important to ameliorate post-surgical functional recovery. A new trial will be carried out with a larger number of cases in order to confirm these results which could have important applications in the clinical perspective.
The abstracts were prepared by incoming Professor Elena Brach del Prever. Correspondence should be addressed to IORS – President office, Dipartimento di Traumatologia, Ortopedia e Mediciana del Lavoro, Centro Traumatologico Ortopedico - Via Zuretti, 29 I-10135 Torino, Italy.
