The Thickness of the Sternocleidomastoid Muscle as a Prognostic Factor for Congenital Muscular Torticollis

OBJECTIVE To examine whether the thickness of the sternocleidomastoid muscle (SCM) could be used as a prognostic factor for congenital muscular torticollis (CMT). METHOD This was a retrospective study conducted in a pediatric rehabilitation service at a tertiary medical center. Fifty-two children who met the following inclusion criteria were included: 1) children who were 3 month-old or younger, 2) children diagnosed with CMT, 3) passive rotation of the face toward the shoulder of the tilted side ≤60°, 4) children who had been managed according to the clinical pathway for CMT, 5) children who had been followed up for 6 months or more after the end of treatment. The duration and total number of stretching exercise sessions were reviewed with reference to the thickness of the SCM. RESULTS Among the 52 children with CMT, 46 children were successfully managed with only stretching exercise of the SCM for 1-6 weeks (group 1: 88.5%) and 6 children were managed with botulinum toxin A injection, surgical release or both in addition to stretching exercise (group 2: 11.5%). The difference in the SCM thickness between the affected and normal sides was significantly greater in group 2 than that in group 1 (p=0.026). A strong correlation was found between the total duration of stretching exercise and the difference in the SCM thickness in group 1 (Pearson' γ=0.429; p=0.003). CONCLUSION Children with a thicker SCM seem to require a longer duration of stretching exercise and other therapeutic interventions in addition to stretching exercise for CMT. Therefore, the thickness of the SCM may be one prognostic factor for CMT treatment.