gms | German Medical Science

Objectives/Interrogation: The goal of surgery of the spastic upper limb is to rebalance forces between spastic and contracted muscles on one side, and paralyzed or pseudo-paralyzed antagonists.

Surgery for contracted muscle involves various standard techniques of muscle lengthening. The spastic component is also amenable to surgical improvement through partial neurectomy, but this procedure has not gained much popularity yet, and reports on outcome are scarce in the literature. In light of our recent anatomical studies (96 cadaver dissections), new guidelines have been described and we have conducted a prospective study in order to re-evaluate the results of this treatment.

Methods: We performed a prospective study on 48 consecutive patients who underwent hyperselective neurectomy (HSN) of one or several spastic muscles of their upper limb(s). Indication of selective neurectomy was spasticity, exclusive of muscle contracture. Patient selection was based on repeated clinical evaluation and pre-operative botulinum toxin injections. HSN consisted in resecting 2/3 or more of every motor branch of the target muscle at the neuromuscular junction. Assessment performed pre-operatively, at 6 months and at last follow-up (average 22.2 months) was based on the resting position, active and passive motion, muscle strength, modified Ashworth and Tardieu scales, several functional scales, ADL questionnaires, and patient satisfaction (VAS).

Results and Conclusions: Twenty-nine adults and 19 children were enrolled in the study. HSN was performed in 56 cases, involving 185 muscles, mostly elbow and wrist flexors. Associated procedures (muscle lengthening, tendon transfers) were performed simultaneously in 35 cases. Results showed a statistically significant decrease of spasticity (Ashworth from 1.4 to 0.7 and Tardieu V1-V3 from 40° to 27°for elbow flexion and from 24.5° to 8° for wrist flexion) without weakening of the involved muscles, increase in the strength of antagonist muscles by 0.4, and improvement of all other parameters. Patient satisfaction averaged 8.5/10. The general trend indicated a minimal loss of correction between 6 and 12 months postop, and then the results remained stable over time.

Although spasticity is difficult to evaluate objectively, these results have been promising. They show effective reduction of spasticity without loss of strength, and improved motion and function. A larger cohort and a longer follow-up will be useful in order to confirm the evolutive trend.