The influence of botulinum toxin A injections into the calf muscles on genu recurvatum in children with cerebral palsy.

Abstract

BACKGROUND:

With cerebral palsy (CP), an equinus deformity may lead to genu recurvatum. Botulinum toxin A (BtA) injection into the calf muscles is a well-accepted treatment for dynamic equinus deformity.

QUESTIONS/PURPOSES:

The purpose of this study was to determine whether BtA injections into the calf muscles to decrease equinus would decrease coexisting genu recurvatum in children with diplegic CP.

METHODS:

In a retrospective study, 13 children (mean age, 5 years) with spastic diplegic CP showing equinus and coexisting primary genu recurvatum, who were treated with BtA injections into the calf muscles, were included. Evaluations were done before and 6 and 18 weeks after intervention using three-dimensional gait analysis and clinical examinations according to a standardized protocol. Basic statistical analyses (power analysis, ANOVA) were performed to compare genu recurvatum before treatment and at 6 and 18 weeks after injection with BtA.

RESULTS:

During stance phase, maximum ankle dorsiflexion was increased substantially from -3.0° ± 14.3° before to 6.2° ± 14.2° 6 weeks after the injections. Despite this, with the numbers available, the amount of recurvatum in stance did not improve with treatment at either 6 or 18 weeks. There was significant improvement of knee hyperextension during stance phase of 6.2° between baseline and 18 weeks after BtA injection, but a genu recurvatum was still present in most patients.

CONCLUSIONS:

Despite improvement of ankle dorsiflexion after injection with BtA, genu recurvatum did not show relevant improvement at 6 or 18 weeks after injection with the numbers available. Because knee hyperextension remained in most patients, other factors leading to genu recurvatum should be taken into consideration. In addition, a botulinum toxin-induced weakness of the gastrocnemius may explain why recurvatum gait was not significantly reduced.

LEVEL OF EVIDENCE:

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

• Authors: Matthias C M Klotz, Sebastian I Wolf, Daniel Heitzmann, Simone Gantz, Frank Braatz, Thomas Dreher
• Journal: Clinical orthopaedics and related research (Clin Orthop Relat Res) Vol. 471 Issue 7 Pg. 2327-32 (Jul 2013) ISSN: 1528-1132 [Electronic] United States
• PMID: 23463290 (Publication Type: Journal Article)

Chemical References

• Neuromuscular Agents
• Botulinum Toxins, Type A

Topics

• Ankle Joint (drug effects, physiopathology)
• Biomechanical Phenomena
• Botulinum Toxins, Type A (administration & dosage)
• Cerebral Palsy (complications)
• Child, Preschool
• Equinus Deformity (drug therapy, etiology, physiopathology)
• Female
• Gait
• Humans
• Injections, Intramuscular
• Joint Deformities, Acquired (drug therapy, etiology, physiopathology)
• Knee Joint (drug effects, physiopathology)
• Lower Extremity
• Male
• Muscle, Skeletal (drug effects, physiopathology)
• Neuromuscular Agents (administration & dosage)
• Recovery of Function
• Retrospective Studies
• Time Factors
• Treatment Outcome