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.