Intérêt de la toxine botulique pour les suites opératoires en chirurgie des membres chez l’enfant infirme moteur cerebral

Abstract

Purpose of the study Spasticity can be the cause of pain in cerebral palsy (CP) children who may suffer increased postoperative pain after orthopedic surgery. Moreover, symptoms can be worsened by abnormal movements, cast immobilization or anxiety. Spasticity must therefore be treated after surgery in CP children. A randomized study has demonstrated that when these children undergo surgical tenotomy, preoperative injections of botulinum toxin have a beneficial effect in terms of pain relief. The aim of this study was to assess the benefit regarding pain and comfort provided by preoperative use of botulinum toxin in total-body CP children undergoing bone surgery. Material and methods Two successive groups of nine total-body CP children were compared in a retrospective study. All patients underwent an orthopedic surgery involving a bone or a multilevel procedure. The second group was treated before surgery with multisite injections of botulinum toxin. The main outcome criteria studied were: efficiency and adverse effects of botulinum toxin, duration of hospital stay and pain, length of level III analgesic treatment (morphine), sleep quality, and skin lesions under cast immobilization. The two groups were similar for mean age (8.7 ± 2.04 versus 10.9 ± 4.37 years) and mean body weight (20 ± 5.6 versus 26 ± 7.7 kg). Mean botulinum toxin (Botox ®/kg) in the second group was 11.6 U (range 9.7 - 14.8). Average time from preoperative botulinum toxin injections to surgery was 27 days (range 23-31). Results There was no significant difference between the two groups, except for the botulinum toxin treatment. The Aschworth scale confirmed the clinical efficiency of the preoperative injections, with no adverse effects. After the surgical procedure, all patients but two had cast immobilization (orthopedic traction, in botulinum group). The mean duration was six weeks in both groups. There was no significant difference in duration of the hospital stay: 7.33 ± 1.5 versus 7.88 ± 1.7 days and duration of level III analgesic treatment (4.33 ± 1.9 versus 4.16 ± 2.5 days). The duration of pain symptoms decreased significantly from 6.87 ± 2.9 to 2.22 ± 1.7 days and sleep quality improved from 7/9 to 1/9 patients with disturbed sleep. Four under-cast skin lesions were noted in the first group but none in the bolulinum group. Discussion We cannot confirm that botulinum toxin before bone surgery induces lesser consumption of analgesic drugs. Our results do however support the hypothesis that treatment of spasticity using preoperative injections of botulinum toxin decreases the duration of postoperative pain and improves the children's comfort. Moreover, postoperative under-cast skin lesions can be prevented. This work suggests that improved patient comfort and pain relief could be achieved by using multisite botulinum toxin injections before orthopedic surgery in spastic total-body CP children.