Pediatric Torticollis Surgery

An end-arterial branch of the superior thyroid artery supplies the middle part of the sternocleidomastoid; obliteration of this end artery may be responsible for the development of muscle fibrosis. (See the image below.) As an alternative, primary trauma that temporarily and acutely obstructs the veins may lead to intravascular clotting in the obstructed venous tree. In infants, this clotting is evidenced by the development of a sternocleidomastoid mass, which eventually disappears and is replaced by fibrous tissue.

Abnormalities in the basal ganglia may be involved in the pathophysiology of spasmodic torticollis.[1] On the other hand, some vestibular abnormalities have been reported that are not explainable solely as secondary to abnormal head and neck movements in spasmodic torticollis but seem to be more intimately related to its pathophysiology. In this respect, abnormal interaction of vestibular signals with higher-order motor commands and disrupted central vestibular processing (perhaps caused by subtle imbalances in the vestibular system) seem particularly important.[2]

The etiology of torticollis is incompletely understood, though several theories have been advanced.[3, 4] Reports on the familial transmission of congenital muscular torticollis have been few. An idiopathic intrauterine embryopathy or the intrauterine development of sternocleidomastoid compartment syndrome may be responsible for the sternomastoid fibrosis.

Congenital structural abnormalities of the vertebrae can also cause torticollis, though osseous torticollis is substantially less common than muscular torticollis.[5]

Recurrent torticollis after surgery is rare (frequency, ~5%).[6] Even in patients older than school age and those who have finished growth, sufficient unipolar or bipolar release of the sternocleidomastoid and intensive postoperative care can generally be expected to yield satisfactory treatment results.[7]

Secondary effects of untreated torticollis include the following:

• Plagiocephaly
• Facial hypoplasia
• Musculoskeletal effects

Plagiocephaly is an asymmetric skull deformity in infants that is caused by flattening of one occiput that leads to secondary flattening of the contralateral forehead. After the torticollis resolves, the plagiocephaly resolves; however, several years may pass before it disappears.[8] Although torticollis can predispose to plagiocephaly without synostosis (PWS), torticollis appears to result from plagiocephaly in a large proportion of cases of plagiocephaly with scoliosis.[9]

Facial hypoplasia is inhibition in the growth of the mandible and maxilla due to muscle inactivity. Clinically significant facial hemihypoplasia develops over 8 months; however, it is obvious in patients at the age of 2-3 years. Facial hypoplasia improves as the child grows, after the torticollis resolves.[10]

Musculoskeletal effects include compensatory ipsilateral elevation of the shoulder, as well as cervical and thoracic scoliosis. Wasting of additional muscles in the neck may be present as a consequence of sternocleidomastoid inactivity.

Congenital muscular torticollis has also been reported to be a significant risk factor for later neurodevelopmental conditions (eg, attention-deficit/hyperactivity disorder [ADHD], developmental coordination disorder, language impairment, and autism spectrum disorder [ASD]), with disorders presenting at different stages of development.[11]

The mass is generally 1-3 cm in diameter. It is a painless swelling in the substance of the sternocleidomastoid muscle and develops in neonates aged 2-3 weeks. In infants, the tumor is hard, and the patient's head is tilted and flexed to the side of the fibrosis.

In older children, however, the tumor is less discrete than it is in younger children, and the sternocleidomastoid muscle appears thickened and foreshortened along its entire length. This thickening restricts rotation and lateral flexion of the neck. This rotation and lateral flexion of the neck is largely responsible for the gradual increase in positional plagiocephaly.[12, 13]

Older children compensate for the head tilt by elevating their shoulder to maintain a horizontal plane of vision (see the image below). The head tilting is further compensated by twisting the neck and back, if required, to maintain a straight line of sight. These compensatory mechanisms do not occur in infants, who do not need to maintain a horizontal plane of vision until they stand up. Also, in older patients, muscular spasms play a role or accompany torticollis.

It is important to differentiate muscular from nonmuscular torticollis. Congenital muscular torticollis is benign; missing a case of nonmuscular torticollis is potentially life-threatening.[14]

During clinical examination, the entire length of the muscle must be palpated to determine if fibrosis or an area of fibrosis is present along the entire length of the muscle. The anterior border of the muscle must be palpated. It generally stands out as a tight band. This may be difficult to detect in small infants because the neck is relatively short.

If the muscle is neither short nor prominent, alternative differential diagnoses must be considered, such as the following:

• Abnormal position in utero
• Cervical hemivertebrae
• Cervical lymphadenitis
• Cervical abscess
• Retropharyngeal abscess
• Ocular muscle torticollis
• Tumors of the posterior fossa
• Atlanto-occipital subluxation
• Sandifer syndrome
• Postural abnormalities

Although the diagnosis of pediatric torticollis is easily made upon physical examination by an experienced clinician, ultrasonography (US) is the most commonly ordered test.[15, 16]

Magnetic resonance imaging (MRI) may be useful in patients with nonmuscular causes of torticollis; however, it is not recommended in asymptomatic patients with infantile torticollis.[17] Evaluation of MRI results correlated with histopathology has demonstrated that if multiple or large low signal intensities that represent increased fibrosis and aberrant dense connective tissue within the sternocleidomastoid are noted, a surgical release should be considered.[18]

Histopathologic findings include fibrous replacement of skeletal muscle fibers that undergo atrophy. The degree of fibrosis and its extent or distribution may vary. Even in neonates, the fibrous tissue is mature. This finding indicates that the disease began before birth.

Management of torticollis in children is primarily nonoperative, generally consisting of parental physiotherapy. The rare indications for surgical management include the following:

• Persistent sternocleidomastoid contracture limiting head movement
• Persistent sternocleidomastoid contracture accompanied by progressive facial hemihypoplasia
• Torticollis in children older than 12 months

Surgical management of congenital muscular torticollis is generally avoided until the child is aged at least 1 year,[19] until conservative methods (eg, physiotherapy) are unsuccessful, and until other differential diagnoses are excluded.

Medical management of torticollis involves conservative treatment.[20] Sternocleidomastoid fibrosis spontaneously resolves in the vast majority of infants. A large prospective study demonstrated that controlled manual stretching is safe and effective in the treatment of congenital muscular torticollis when a patient is seen before the age of 1 year.[21, 22]

Physiotherapy may be recommended; however, there is little evidence to indicate that this alters the course of the condition if the patient is older than 1 year. Evidence-based guidelines for the use of physical therapy (PT) in patients with congenital muscular torticollis have been developed by the American Physical Therapy Association (APTA).[23]

Published data demonstrate that patients with a thicker sternocleidomastoid, a lower birth weight, and a history of breech delivery have a longer rehabilitation duration.[24, 25]

Kinesiology taping is another approach that is sometimes adopted in conservative management.[26] When applied on the affected side, it has an immediate effect on the muscle function scores for the muscular imbalance in the lateral flexors of the neck.

Botulinum toxin (BTX) type A has been injected into the sternocleidomastoid for the treatment of congenital muscular torticollis in pediatric and adult patients.[27] Modest benefit with improved range of motion (ROM) has been reported, but studies have been relatively few and follow-up relatively short.

In a study of 39 children with treatment-resistant congenital muscular torticollis, Limpaphayom et al evaluated the adjunctive use of BTX injection into the sternocleidomastoid, followed by PT.[28]  None of the patients required tendon-lengthening surgery. At the final evaluation, there were improvements in both head tilt (18.7º ± 6.8º vs 1.7º ± 2.4º; mean difference, 16.9º) and neck ROM (56.0° ± 11.7º vs 86.0º ± 3.8º; mean difference, 30.0º). Caregivers were satisfied with the treatment protocol, and no untoward effects were observed during the study period.

In a systematic review and meta-analysis of one nonrandomized experimental study and nine cases or case series (N = 411), Qiu et al assessed the effectiveness and safety of botulinum toxin injections for congenital muscular torticollis and found an 84% overall effective rate, a 9% rate of conversion to surgery, and a 1% adverse reaction rate (primarily injection-site erythema and transient dysphagia).[29]

Only about 4-5% of patients are surgically treated, generally after the age of 1 year.

Successful bilateral pallidal stimulation has been reported in a patient with Meige syndrome and spasmodic torticollis.[30]

Patients whose pathology does not resolve after 12 months of physical therapy or who develop facial asymmetry or plagiocephaly during the follow-up period should undergo surgery to achieve the best cosmetic result.[31, 32] In delayed cases, additional surgery may be needed for the best cosmetic and functional result.

Operative details

Surgery is performed with the patient under general anesthesia. A 3- to 4-cm transverse skin incision is made about 1 cm over the sternal and clavicular origins of the affected muscle. (See the image below.) The platysma is carefully divided along the line of incision to avoid injury to the external jugular vein. The two heads of the sternocleidomastoid are dissected free. The muscle is divided with diathermy to prevent bleeding. The platysma is then sutured with absorbable 4-0 skin suture, and the skin is closed with continuous 4-0 nonabsorbable skin suture.

Ekici et al described an approach to surgical management of congenital muscular torticollis that used the Z-plasty technique.[33]

Surgical treatment of torticollis via an endoscopic or minimal-access approach has been reported. Sasaki et al described surgical correction of muscular torticollis via endoscopic tenotomy of the sternocleidomastoid.[34]  Tokar et al described a para-axillary subcutaneous endoscopic approach (PASEA) to congenital muscular torticollis and found it to be an alternative worth considering for surgeons with experience in pediatric minimally invasive surgery.[35]  Teja et al reported good results with "stealth" surgery (ie, subcutaneous endoscopic surgery) in five children with torticollis.[36]  Pan reported good results with transaxillary subcutaneous endoscopic sternocleidomastoid division.[37]

Hematomas may develop because of inadequate hemostasis during surgery. Incomplete division may cause the condition to persist.

Follow-up should be continued until the torticollis resolves completely, until head and neck movement normalize, and until cervical and thoracic scoliosis is resolved in older children.