Torticollis or “wry neck” is a condition in which the child holds the head tilted to one side. Though torticollis may rarely occur due to bony abnormalities in the cervical spine, the commonest form of torticollis occurs due to tightness of the sternocleidomastoid muscle. This form of torticollis is called “Congenital Muscular Torticollis” (CMT).
Relevant Surgical Anatomy:
The sternocleidomastoid muscle extends from the mastoid process (back of ear) to the clavicle (collar bone) and sternum below (Figure 1).
Tightness of this muscle results in torticollis deformity in which the head is tilted to the side of the tight muscle and chin is rotated to the opposite side (Figure 2).
Contrary to popular belief, CMT is NOT caused by trauma occuring during birth. On the other hand, it is now believed that CMT occurs due to blockage of blood supply to the sternocleidomastoid muscle which results in muscle fibrosis and tightness. Cutting off of blood supply to the muscle may occur secondary to intra-uterine overcrowding as evidenced by higher incidence of CMT in childre born by twin pregnancy or in breech position.
Children with CMT have a higher incidence of other “packaging disorders” (disorders caused by intra-uterine over-crowding), including Developmental Dysplasia of Hip (DDH) and Metatarsus Adductus (inwards turning of toes of feet).
In new-born babies, swelling may be seen in sternocleidomastoid muscle. This swelling is called “Sternomastoid tumour”. The swelling resolves over a period of few days, but the muscle may become tight and fibrotic leading to torticollis deformity.
Children with CMT usually develop plagio-cephaly (flattening of head on the side of torticollis). Facial asymmetry with flattening of face on the side of torticollis is also seen in torticollis which fail to correct by the age of one year.
Diagnosis of CMT is usually made on the basis of clinical examination. Taut sternocleidomastoid muscle can be felt. Head is seen to be tilted to the side of tight muscle and chin is rotated to the opposite side.
X-rays are performed to rule out any bony abnormalities in the spine. In rare cases, MRI/ CT scan may be recommended if findings on clinical examination and X-rays are not conclusive. Occasionally, torticollis may occur secondary to eye abnormalities and evaluation by eye specialist may be advised in cases of suspicion of eye abnormalities.
After diagnosis, the first line treatment in CMT is physiotherapy. Exercises performed are aimed at stretching out the tight sternocleidomastoid muscle. Hence, the head is tilted to the opposite side of taut muscle, while chin is rotated to the same side. The deformity may resolve with physiotherapy in approximately 50% cases. The chances of success are higher if physiotherapy is instituted early in infancy. However, if the deformity persists beyond the age of one year, surgery is usually needed for correction of the deformity.
Surgery is needed for cases of CMT which fail to resolve with an adequate trial of physiotherapy. However, we prefer to perform surgery only after the age of three to four years which is the ideal age for surgery.
Surgery in CMT consists of release of the sternocleidomastoid muscle. The sternocleidomastoid muscle has two heads (sternal and clavicular) and both heads are released at their insertion into the bone. When the release is done only at the lower end, it is called a “unipolar release”. On the other hand, when the muscle is released at both lower and upper (behind the ear) ends, it is called a “bipolar release”.
Outcomes of treatment of Congenital Muscular Torticollis are excellent. The deformity may resolve with physiotherapy in 50% cases if initiated in the first year of life. Surgery if needed results in excellent correction of torticollis deformity. Associated facial asymmetry also corrects within a period of one to two years following surgery.