INTRODUCTION
Stroke is the third cause of death and the leading cause of handicap among industrialized
countries (1). Spasticity following stroke is responsible for spastic equinovarus foot (SEF)
in 18% of cases (2). Spastic equinovarus foot is due to spasticity (muscle hypertonia) of the
calf muscles (soleus, gastrocnemius and tibialis posterior), often complicated by contracture
and by the weakness of peroneus longus and peroneus brevis muscles (3). Therefore, stroke
patients walk slowly, and often require assistive device as orthosis or canes. This
disability limits their social participation and their quality of life.
Spastic equinovarus foot treatments include oral medications, physical therapy, orthosis,
chemical denervations (botulinum toxin, alcohol or phenol injections), selective neurotomy
and orthopedic surgery (4, 5). Intra-muscular botulinum toxin injection induces a chemical
denervation reducing spasticity of injected muscles. Functional block of the neuromuscular
junction due to botulinum toxin is reversible and lasts about 3 months. Therefore, this
expensive treatment must regularly be administered, with a risk of antibodies development.
Selective neurotomy is a neurosurgical procedure consisting in partially and selectively
cutting motor branches innervating the spastic muscles. For a low cost, it can permanently
reduce muscle spasticity.
Botulinum toxin injection effectiveness has largely been demonstrated in spastic equinovarus
foot treatment by double-blind randomised controlled trials against placebo (6, 7, 8).
Selective tibial nerve neurotomy effectiveness has only been suggested in spastic equinovarus
foot treatment by uncontrolled and unrandomised case reports (9, 10, 11).
International Classification of Functioning, Disability and Health (ICF) of the World Health
Organisation (www.who.int / icidh, 2001) is the framework of the Physical and Rehabilitation
Medicine (12). This model describes how a disease can influence patient impairments, activity
and participation. Spastic equinovarus foot treatments have already been evaluated in the
impairments field: spasticity, muscle strength, walking parameters and gait analysis
variables. These treatments should also demonstrate their effectiveness on the patient
activity (disability) and on his participation (quality of life).
OBJECTIVES
The aim of the present project is to study the effectiveness of selective tibial nerve
neurotomy on the spastic equinovarus foot, by comparing it with botulinum toxin injection.
The functional assessment will explore the three ICF domains.
METHODS
We will recruit 20 chronic stroke patients presenting with spastic equinovarus foot. This
spastic equinovarus foot will be due to calf muscles spasticity without contracture. This
spasticity will not have been managed effectively by physical therapy.
First, a lidocaïne selective diagnostic motor branch block will systematically be carried out
to confirm the treatment indication, and to determine the muscles and / or nerves to treat
(14). Once the muscles responsible for the spastic equinovarus foot will be identified, they
will surgically or chemically be denervated.
Than, patients will be randomized in two groups:
Patients will be assessed before treatment, 2 months and 6 months after treatment among the 3
ICF domains. Impairments will be assessed by the Stoke Impairment Assessment Set (SIAS), the
Ashworth and Tardieu scales (spasticity) and the MRC scale (muscle strength). Spasticity and
gait disorders will quantitatively and objectively be evaluated by the muscle stiffness
measurement (15) and an instrumented gait analysis (11). Disability will be evaluated by the
ABILOCO scale (16) and the participation (quality of life) by the StrokeQol scale (17) and
the SF-36 questionnaire.
The patients selection, the lidocaïne hyperselective diagnostic blocks, the botulinum toxin
injections and the selective neurotomies will be achieved at Cliniques universitaires
Mont-Godinne. The functional assessment (clinical evaluation, gait analysis, muscle stiffness
measurement) will be achieved in the Physical Medicine and Rehabilitation department (READ
unit) by a blinded assessor.
PERSPECTIVE
From this study, we hope to demonstrate the effectiveness of the selective neurotomy in
spastic equinovarus foot treatment among the 3 ICF domains (impairment, activity and
participation). This should promote this effective, permanent and cheap spastic equinovarus
foot treatment.
