Article

The aim of this study was to examine both the tendon and muscle
components of the medial gastrocnemius muscle-tendon unit in children with
cerebral palsy (CP) and equinus gait, with or without contracture. We also
examined a small number of children who had undergone prior surgical lengthening
of the triceps surae to address equinus contracture. METHODS: Ultrasound was used
to measure Achilles tendon length and muscle-tendon architectural parameters in
children of ages 5 to 12 years. Muscle and tendon parameters were compared among
4 groups: Control group (N=40 limbs from 21 typically developing children),
Static Equinus group (N=23 limbs from 15 children with CP and equinus
contracture), Dynamic Equinus group (N=12 limbs from 7 children with CP and
equinus gait without contracture), and Prior Surgery group (N=10 limbs from 6
children with CP who had prior gastrocnemius recession or tendo-achilles
lengthening). The groups were compared using analysis of variance and Scheffe
post hoc tests. RESULTS: The CP groups had longer Achilles tendons and shorter
muscle bellies than the Control group (P<0.001). Normalized tendon length was
also longer in the Prior Surgery group compared with the Static Equinus group
(P<0.001). The Prior Surgery group had larger pennation angles than the CP groups
(P< or =0.009) and tended to have shorter muscle fascicle lengths (P< or =0.005
compared with Control and Static Equinus, P=0.08 compared with Dynamic Equinus).
Similar results were observed for pennation angles and normalized muscle fascicle
lengths throughout the range of motion. CONCLUSIONS: Children with spastic CP and
equinus gait have longer-than-normal Achilles tendons and shorter-than-normal
muscle bellies. These characteristics are observed even in children with dynamic
equinus, before contracture has developed. Surgery further lengthens the tendon,
restoring dorsiflexion but not normal muscle-tendon architecture. These
architectural features likely affect function, possibly contributing to
functional deficits such as plantarflexor weakness after surgery. LEVEL OF
EVIDENCE: Level II, prospective comparative study.

Langue : ANGLAIS

Tiré à part : OUI