Contralateral Involvement of Congenital Muscular Torticollis and Clavicular Fracture.

Congenital muscular torticollis (CMT) is known to concur with some conditions such as developmental dysplasia of the hip or brachial plexus injury, which gives us some insights for pathogenesis of CMT. Although clavicular fracture is the most common fracture in newborns, little is known about concurrence of CMT and clavicular fracture. Our clinical experience led us to realize that concurrence of CMT and clavicular fracture tended to occur on the contralateral side for each other rather than the ipsilateral side. This study aimed to verify contralateral concurrence of CMT and clavicular fracture. This is a retrospective cohort study in a tertiary hospital, including 996 subjects with CMT. Concurrent clavicular fracture was found in 20 of 996 subjects with CMT, with the concurrence rate being 2.01%. Concurrent clavicular fracture and clavicular fracture occurred on the contralateral side for each other in 18 subjects (90%) rather than the ipsilateral side. This contralateral concurrence between side of CMT and clavicular fracture was significant (P = 0.001), with an odds ratio of 81 (P = 0.0032). Concurrent clavicular fracture and clavicular fracture seem to occur significantly more on the contralateral side for each other. Underlying mechanism for consistent contralateral concurrence needs to be verified in the near future.