Definition
- sternomastoid on one side is fibrous & fails to elongate as the child grows resulting in progressive deformity
Aetiology
- Unknown
- ? Ischaemia
- muscle may have suffered ischaemia from a distorted position in utero
- supported by the association with breech presentation & DDH
- muscle may have suffered ischaemia from a distorted position in utero
- ? trauma
- May be due to birth trauma
Epidemiology
- Males > Females
- Right > Left
- Associations
- DDH & acetabular dysplasia in 10 – 20%
- may be related to intra-uterine posture with an ↑ incidence in breech deliveries & difficult labours
Anatomy
- SCM has sternal and clavicular heads
- Inserts on the mastoid process and lateral superior nuchal line
- Supplied by the spinal accessory nerve (CN XI)
- Contraction tilts the head to the same side and rotates the chin to the opposite side
- Divides the neck into anterior and posterior triangles
Pathology
‘Sternomastoid Tumour’
- In 20% a lump (sternomastoid ‘tumour’)is noticed in the first few weeks of life in the belly of the sternocleidomastoid on the side of the tilt
- Usually well defined & may involve one or both heads of the sternomastoid
- At this stage there is no deformity or loss of movement & deformity becomes apparent usually at 3 – 4 years of age
- Shortening of the muscle results in the mastoid process approximating the sternal notch (the ear becomes lower & further forward) & the entire face is tilted down on the affected side- the face is shorter on the affected side
- sternomastoid feels tight & cord like
Classification
Cheng clinical groups
| Group | Description |
|---|---|
| Sternomastoid tumour | Palpable mass within the SCM |
| Muscular torticollis | Tight SCM without a mass |
| Postural torticollis | Head posture without tightness or mass |
- Severity graded by deficit of passive rotation compared with the normal side
History
- Head tilt noticed in the first weeks of life
- Neck lump appearing at 2 to 4 weeks, resolving over months
- Breech presentation or difficult delivery
- Preferential head position and plagiocephaly
- Absence of visual, neurological or feeding symptoms
Examination
- Head tilted towards the affected side, chin rotated to the opposite side
- Firm nontender mass within the SCM in sternomastoid tumour
- Reduced passive rotation towards and lateral flexion away from the affected side
- Plagiocephaly and facial asymmetry
- Hip examination for associated DDH
- Feet for other packaging deformities such as metatarsus adductus
- Eye and neurological examination to exclude other causes
Investigations
X-rays
- Normal
- Performed to exclude a congenital cervical abnormality
Differential Diagnosis
- Klippel Feil syndrome and other congenital cervical vertebral anomalies
- Ocular torticollis from superior oblique palsy
- Atlantoaxial rotatory subluxation, including Grisel syndrome after pharyngeal infection
- Posterior fossa tumour or Chiari malformation
- Benign paroxysmal torticollis of infancy
- Sandifer syndrome from gastro-oesophageal reflux
- Cervical spine infection or tumour
Treatment
- Initial
- If a child has a sternomastoid tumour every effort should be made to prevent deformity developing
- physiotherapy, stretching & splintage
- If a child has a sternomastoid tumour every effort should be made to prevent deformity developing
- If deformity persists
- surgery at 1 – 4 years (Best time for operation is 18 months to 2 years)
- subcutaneous tenotomy (distal end) with care to avoid neurovascular structures
- open division of either the upper or lower end (recurrence rate following surgery less than 5%)
- surgery at 1 – 4 years (Best time for operation is 18 months to 2 years)
- Operative release is indicated
- if nonoperative treatment fails
- if late presentation with rigid deformity
- post op
- correction is maintained using a splint or collar worn for several months until head is held straight
Complications
- Plagiocephaly and facial hemihypoplasia if untreated
- Compensatory cervicothoracic scoliosis
- Spinal accessory nerve injury during release
- Recurrence after unipolar release
- Loss of normal SCM contour and visible scar
Prognosis
- 5% recurrence rate
- correction before the age of 4 years the facial asymmetry can resolve
Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.