NORMAL APPEARANCES:
In Fig. 1 we demonstrate the 'column' concept of spinal alignment as applicable to the cervical spine.
In Fig. 2 we show the normal relationship of the atlantoaxial junction when viewed in the sagittal plane. In Fig. 3 the normal predental space (as measured from the posterior cortex of the anterior arch of C1 to the anterior cortex of the odontoid process of C2). The normal apparances of the C1 and C2 ossification centres are illustrated in Fig. 4. C1 is formed from three primary ossification centres with fusion of the posterior arch by 5 years and the anterior arch by 8 years.
C2 has five primary ossification centres which have usually fused by the age of 12. The craniocervical junction and cervical spine are strengthened by several ligaments,
depicted in Fig.
5.
PSEUDOSUBLUXATION ( Fig. 6 ):
2 children with neck pain following minor trauma. Pseudosubluxation is a normal variant seen at C2/C3 or less frequently C3/C4. It is present in up to 46% of children aged <8 years. Spinous process alignment remains normal and the apparent abnormality will 'correct' with extension of the neck.
OS ODONTOIDIUM ( Fig. 7 ):
16 year old patient. Incidental finding on CT of the orbits.
An anatomical variant of C2 believed to be congential or represent a previously undiagnosed fracture through the odontoid growth plate before age 5 years.
May cause instability.
ASYMMETRICAL STERNOCLEIDOMASTOID MUSCLES ( Fig. 8 ):
A 9 year old with longstanding right sided head tilt. There was a past history of shoulder dystocia at birth which had resulted in a brachial plexus injury. Asymmetry of the sternocleidomastoid muscles was demonstarted on imaging and considered to be causative. He was referred for physiotherapy.
NEONATAL FIBROMATOSIS COLLI ( Fig. 9 ):
A benign condition which is usually unilateral. There is a slight male predominance.
It is due to fibromatosis within the sternocleidomastoid muscle and is believed to be secondary to birth trauma (e.g.
forceps delivery). We present selected ultrasound images of two patients with this condition.
KLIPPEL-FEIL SYNDROME ( Fig. 10 ):
A 12 year old patient who was referred for ultrasound because of a prominent left sternoclavicular joint. The radiologist identified a scoliosis and arranged radiographs of the spine and thorax.
A diagnosis of Klippel-Feil syndrome was ultimately made. This syndrome is due to an error in segmentation which occurs between the 3rd and 8th weeks of gestation. It results in fused cervical vertebrae and is associated with a Sprengel deformity of the shoulder,
cervical spondylosis,
aortic arch abnormalities and unilateral renal agenesis. The incidence is approximately 1 in 40,000 live births.
ATLANTOAXIAL INSTABILITY ( Fig. 11):
A 5 year old child with Down Syndrome. Normal anterior distance is 3mm in adults and up to 5 mm in children under 8 years. Ligamentous laxity or bone abnormality leads to excessive movement at the C1/C2 junction.
The distance will change on flexion and extension of the neck and neurologic symptoms can occur if there is encroachment on the spinal canal. This condition is also associated with other congenital syndromes including Morquio syndrome,
Marfan disease and Neurofibromatosis type 1.
ATLANTOAXIAL ROTATORY SUBLUXATION / FIXATION (AARF):
In AARF the anterior facet of C1 becomes fixed on the ipsilateral facet of C2 and may be associated with disloaction of the lateral mass of C1 on C2.
CASE 1 (Fig.
12 ):An 8 year old with a 5 month history of painful fixed torticollis. There was a history of torticollis at birth which improved with physiotheraoy. In this case the child was referred to the spinal surgeons at Sheffield Childrens Hospital (UK) where the rotational deformity was reduced and internally fixed with an occipital plate and posterior screws from C0 to C2.
CASE 2 (Fig. 13 ): A 2 year old patient currently awaiting spinal surgery.
ANOMALOUS CRANIOCERVICAL JUNCTION:
CASE 1 (Fig. 14): Anomalous craniocervical junction in a 20 year old patient.
CASE 2 (Fig. 15: Anomalous craniocervical junction and C1 vertebra in a 12 year old patient with longstanding head tilt.
The patient has recently been referred to a tertiary paediatric centre for an opinion.