Disorders of the Neck

Treatment

Nonsurgical

Excellent results with massage and a stretching program can be achieved in approximately 90% of patients. ^{, , , ,} At the time of diagnosis, parents are instructed in the technique of stretching the contracted SCM muscle by rotating the infant’s chin to the ipsilateral shoulder and simultaneously tilting the head toward the contralateral shoulder. The exercises should be done gently but with the goal of attaining full passive range of motion—both rotation and tilting—as quickly as possible ( Fig. 8.8 ). Besides stretching, positioning toys and other maneuvers to solicit active rotation toward the involved side are important to actively overcome the SCM fibrosis.

The plagiocephaly associated with CMT garnered increased attention after the recommendations of the American Academy of Pediatrics in 1992 that infants be placed on their backs during sleep to reduce the risk of sudden infant death syndrome. ^{, , , ,} Pressure exerted on the infant cranium in the supine position induces flattening of the parieto-occipital region. This force is accentuated in CMT because the infant consistently lies on one side, with a resulting compensatory anterior displacement of the ipsilateral ear and forehead. Natural history studies of the long-term consequences of such posterior positional plagiocephaly are sparse, but some investigators suggest that moderate to severe cases may result in facial asymmetry requiring maxillary osteotomies in adulthood. Two common forms of treatment for plagiocephaly include (1) repositioning of the neonate coupled with the organized stretching program for the torticollis and (2) external orthotic treatment with molding helmet therapy. Preliminary evidence suggests that infants with mild to moderate plagiocephaly may respond well to consistent repositioning and observation, whereas those infants who fail to respond to this form of treatment and who have more severe deformity may be best treated with a helmet. However, controlled clinical trials are needed before any form of intervention can be verified as effective in the treatment of occipital plagiocephaly. Currently, this form of treatment is most commonly prescribed and monitored by craniofacial surgeons and neurosurgeons.

Surgical treatment of CMT for infants and toddlers is rarely indicated. The natural history of the untreated deformity is benign; >90% of patients eventually develop an adequate range of motion and an adequate cosmetic appearance; <10% of patients eventually require surgery. If a significant restriction of motion (lacking 30 degrees or more of full rotation) or facial asymmetry persists after the child achieves walking age, surgical intervention may be considered. However, surgical release has little advantage and much disadvantage in the young child, and we prefer to wait until just before school age before a decision on surgery is made.

The reasons for waiting are both technical and age related. Operative procedures include subcutaneous tenotomy, open tenotomy of the lower SCM insertions, bipolar tenotomy, and muscle excision. Although tenotomy or excision allows an immediate increase in head excursion, this procedure is more likely to lead to recurrent contracture and a cosmetic deficit in the column of the neck resulting from the loss of muscle bulk. The earlier the surgical procedure is performed, the more technically difficult Z-plasty reconstruction will be because of the diminutive size of the structures.

The complications of surgery in infancy include scar formation, recurrent contracture with severe fibrosis, and, most important for this cosmetic deformity, unacceptable cosmetic appearance because of removal of the SCM column of the neck line, which produces an unsightly “hole” at the distal insertion in the sternum and clavicle, an outcome reported in 40% to 90% of patients. ^{, , ,} Because of the excellent results obtained if surgery is delayed, there is simply no urgency for surgery in infancy for CMT.

Surgical

Most authors favor surgery, when indicated, by 6 years of age. ^, Others have extended this period upward to age 12 years and beyond. Functional outcome, as judged from range-of-motion evaluation, is no different if surgery is performed between the ages 1 and 6, and the disadvantages of early surgery just enumerated decrease as the age of the child increases. Older children more readily accept postoperative physical therapy, especially concentrating on proprioceptive re-education of abnormal head posture. Poorer results, primarily related to unacceptable facial asymmetry or limitation of motion, are restricted to the most severe cases, although the benefits of later surgery in correcting head tilt and overall cosmesis are well established. ^{, ,}

We prefer the bipolar lengthening technique (Ferkel) for patients needing surgery ( Video 8.1 ). The release of the SCM muscle includes careful reconstruction of the “column” of the SCM by either (1) performing Z-plasty of the clavicular insertion and releasing the sternal insertion from bone or (2) transecting the sternal portion of the muscle 1 to 2 cm proximal to its insertion, releasing the clavicular insertion from bone, and transferring the latter to the remaining distal sternal portion ( Fig. 8.9 ). Such a Z-plasty reconstruction is technically difficult to perform in the infant or toddler, and this explains why early release produces cosmetically unappealing results. Release at the mastoid process facilitates more vigorous and complete release of the patient’s head so that postoperative physical therapy can be more effective. The mastoid release should be performed at the bony insertion to avoid possible injury to the spinal accessory nerve. Skin incisions should never be placed over the clavicle because of unaesthetic scar spreading.

Surgical outcomes in older children have also been quite satisfactory ( Fig. 8.10 ). There is therefore little to criticize with persistence of nonoperative management of the young child, with surgical release, if indicated, performed sometime after age 5.

Postoperative care of the patient who has undergone bipolar release includes reinstitution of stretching exercises as soon as pain has abated and the surgical incisions have adequately healed. ^{, , ,} Historically, postoperative treatment included the use of all types of braces and cast correction but we have found that active range-of-motion exercises produce excellent results, and use of postoperative immobilization is somewhat obsolete. Residual fascial bands ^, can lead to recurrence of deformity. These bands are best avoided by delaying the surgical procedure until the recommended age of at least 5 years.

Clinical Features

The infant with the classic triad of a low hairline, webbed neck, and limited motion with or without torticollis presents no problem in diagnosis (see Fig. 8.11 ). Patients with less obvious signs of classic KFS anomalies are usually diagnosed from the restricted motion associated with vertebral fusions. The finding of torticollis and restricted range of motion, without an obvious SCM contracture, should prompt radiograph evaluation of the cervical spine. Screening for other vertebral anomalies is appropriate if any cervical fusions are found.

Once vertebral fusions in the cervical spine are documented, a general pediatric evaluation should be undertaken. Renal ultrasonography is an appropriate screening test to diagnose genitourinary anomalies. Magnetic resonance imaging (MRI) of the cervical spinal cord and craniocervical junction is recommended whenever any orthopaedic procedure is contemplated, and it certainly is indicated for evaluation of symptoms related to spinal cord compression or stenosis or instability.

Cervical scoliosis anomalies, including KFS, usually present for evaluation of painless deformity, which is managed in a fashion similar to that for congenital scoliosis. Because the cervical spine has no room for a compensatory curve to develop to keep the head upright and compensated, any progression of cervical scoliosis as the cause of a patient’s head tilt must be aggressively treated to avoid head tilt that is not correctable or severe compensatory scoliosis that decompensates the trunk ( Fig. 8.13 ; see also Fig. 8.11D ).

Patients with KFS anomalies may present at an older age with pain, radiculopathy, or myelopathy secondary either to spinal cord compression in a congenitally anomalous, narrow canal or to instability at unfused levels. ^, Torticollis may or may not be present, or it may have been recently acquired at the time of symptom appearance when it was previously absent. Patients with extensive vertebral fusions, often including C2–3, may develop hypermobility at an unfused C1–2 level (see Fig. 8.12E ). Any unfused segment adjacent to extensive synostosis may eventually become hypermobile, with or without neurologic symptoms. ^{, ,} Thus an adolescent with mild non-progressive deformity may develop symptomatic hypermobility after years of being asymptomatic, although rarely before 13 years of age. Degenerative changes at the hypermobile segments may produce just enough spinal cord or nerve root impingement in a young adult to produce radiculopathy and myelopathy. Degenerative stenosis without hypermobility may result in subaxial cervical segments when osteophytes and disk degeneration progress in adult life. Basilar invagination must be evaluated if neurologic signs/symptoms of brainstem involvement develop ( Box 8.2 ) .

BOX 8.2

Neurologic Signs/Symptoms in Klippel-Feil Syndrome

Sign/Symptom	Pathogenesis
Motor deficit	Stenosis w/ myelopathy
Sensory deficit	Same
Hyperreflexia	Same
Ataxia	Cerebellar lesion
Dizziness	(e.g., Arnold-Chiari)
Nystagmus
Cranial nerve deficit	Brainstem compression
Dysphagia	(e.g., basilar invagination)
Dysphonia
Syncope	Vertebral artery compression
Seizures	(e.g., basilar invagination)
Ataxia

Radiographic Findings

Imaging studies of the cervical spine, especially the craniocervical junction, are mandatory for patients with KFS, especially for patients with neurologic compromise. Positioning for imaging studies may be problematic because of the shortened neck and relative lack of motion. Overlapping shadows from the mandible and occiput can confound interpretation of plain radiographs. A lateral radiograph of the skull, rather than of the cervical spine itself, best demonstrates the presence of occipitocervical bony abnormalities by eliminating some of the obliquity and rotational overlapping seen with torticollis. If C1 has been assimilated into the occiput, the lateral skull film is helpful in determining whether C1–2 has any pathologic process. Once anomalous osseous structures are visualized on a screening radiograph, further studies by computed tomography (CT), with or without three-dimensional reconstruction, and MRI to evaluate the brainstem and cervical spinal cord are necessary.

Basilar invagination is screened for by a good-quality lateral radiograph which may show upward migration of atlantoaxial structures, particularly the odontoid, into the foramen magnum. Knowledge of the traditional radiographic lines—especially the McGregor line—is useful in screening for basilar impression. The McGregor line, drawn from the upper surface of the posterior edge of the hard palate to the most caudal point of the occiput, is the most reproducible and interpretable of these radiographic landmarks ( Fig. 8.14 ). The McRae line defines the opening of the foramen magnum and truly defines basilar impression because the odontoid projects above this line in patients who are symptomatic. Modern imaging studies, such as CT with sagittal or three-dimensional reconstruction, show the osseous relationships more clearly. If any question of neural impingement exists, MRI is the more revealing study.

Equally important is the determination of impending stenosis or cord impingement by evaluating the space available for the cord (SAC) and its corollary measurement at C1–2, the atlantodens interval (ADI) ( Fig. 8.15 ; also see Fig. 8.12 ). These intervals are usually determined on lateral flexion-extension radiographs, generally obtained with the patient awake and voluntarily flexing the head. The SAC is the distance between the posterior edge of the dens and the anterior edge of the posterior ring of the atlas or the foramen magnum. A SAC of 13 mm or less is associated with neurologic compromise. In patients with hypermobility, as suggested by an ADI of more than 4.5 mm between flexion and extension, measurement of the SAC gives a reasonable evaluation of how tenuous the neurologic situation may be. Up to 4.5 mm of motion at the ADI is considered normal in children younger than 8 years of age, whereas older children and adolescents should have an ADI of less than 2 mm. ^,

Normal range of motion at the atlantooccipital joint has not been defined. The occiput-C1 articulations are primarily saddle-shaped, elliptic surfaces that allow flexion and extension but little rotation or lateral flexion. Instability of this joint, which is much less common than instability of C1–2, is not well described. According to Tredwell and colleagues, posterior subluxation of the atlantooccipital joint in extension of more than 4 mm suggests instability. This can be measured from the excursion of the basion or occipital condyles in relation to a fixed point, usually the posterior edge of the anterior ring of C1 during flexion and extension ( Fig. 8.16 ). The Power ratio identifies anterior occiput-C1 instability, but because most instabilities are more obvious in extension, this ratio may not be as useful. Normal occiput-C1 translation should be no more than 1 mm in adults, and thus the importance of measuring the SAC on either plain radiographs or flexion-extension CT or MRI scans may be more critical at the atlantooccipital joint.