Objective: To document the sternocleidomastoid (SCM) muscle fibrosis in congenital muscular
torticollis (CMT) infants with quantified echotexture and measured thickness during the
Design: Cohort study. Setting: Rehabilitation department in a tertiary care hospital.
Participants: Infants with clinical diagnosis of CMT, without any neurological presentation,
cervical spin abnormality, and developmental dysplastic hip problem, were recruited in the
Intervention: All subjects had physiotherapy for at least 3 months. They underwent at least
two times of clinical assessment and ultrasonographic examination (1) for bilateral SCM
muscles during the follow-up period.
End of follow-up: Subjects who still had prominent clinical presentations after physiotherapy
for 6 months or were older than 1 year would receive surgery. Subsided presenting clinical
features determined by the clinician was the other end-point of this investigation.
Main Outcome Measures: The K value, derived from the difference of echo intensities (2)
between the involved and uninvolved SCM muscles on longitudinal sonograms, was used to
represent the severity of muscle fibrosis in CMT infants. Bilateral SCM muscle thickness and
involved-to-uninvolved thickness ratio (Ratio I/U) were also obtained from longitudinal
sonograms. Clinical outcome was also recorded.