Klippel-Feil Syndrome: Pathogenesis, Diagnosis, and Management

Abstract

Klippel-Feil syndrome (KFS), or congenital fusion of the cervical vertebrae, has been thought to be an extremely rare diagnosis. However, recent literature suggests an increased prevalence, with a high proportion of asymptomatic individuals. Occurring as a sporadic mutation or associated with several genes, the pathogenesis involves failure of cervical somite segmentation and differentiation during embryogenesis. Most commonly, the C2-C3 and C5-C6 levels are involved. KFS is associated with other orthopaedic conditions including Sprengel deformity, congenital scoliosis, and cervical spine abnormalities, as well as several visceral pathologies. There are several classification systems, some based on the anatomic levels of fusion and others on its genetic inheritance. Management of patients with KFS primarily involves observation for asymptomatic individuals. Surgical treatment may be for neurologic complaints, correction of deformity, concomitant spinal anomalies, or for associated conditions and varies significantly. Participation in sports is an important consideration. Recommendations for contact sports or activities depend on both the level and the number of vertebrae involved in the fusion. A multidisciplinary team should be involved in the treatment plan and recommendations for complex presentations.

Application of C2 subfacetal screws for the management of atlantoaxial dislocation in patients with Klippel-Feil syndrome characterized by a narrow C2 pedicle and high-riding vertebral artery

“…C2-3 congenital fusion is often associated with AAD, which results in neurological dysfunction and requires reduction and fixation to relieve ventral cervical cord compression [ 10 , 15 ]. Pedicle screws insertion is the commonly used technique for C2 fixation.…”

“…Common symptoms of the syndrome are short neck, low hairline, and limited head movement [ 7 ]. C2-3 is a common fusion zone that is often associated with the C0-1 fusion zone, which increases the stress on the atlantoaxial joint, leading to atlantoaxial dislocation (AAD) [ 10 , 15 ]. Therefore, the stabilization of the atlantoaxial joint by fixation is the primary treatment strategy for patients with C2-3 fusion and AAD [ 4 ].…”

The type of cervical disc herniation on MRI does not correlate to clinical outcomes

“…Exclusion criteria were: patients who had undergone previous surgery on the cervical spine (either anterior or posterior); those with no active motion of the target level on dynamic studies; those with increased anteroposterior translation of the target level by > 3 mm on dynamic studies; those with a fused or very narrow disc levels (central < 3 mm); severe segmental kyphosis of the involved disc level by > 3°; those with neck pain without radicular symptoms; evidence of myelopathy; infection; metabolic and bone diseases (such as osteoporosis and severe osteopenia); trauma or neoplasia of the cervical spine; a spinal anomaly (such as Klippel Feil syndrome, 10 ankylosing spondylitis, 11 or ossification of the posterior longitudinal ligament); 12 evidence of a psychiatric disorder; those who did not speak Dutch; or those who planned to leave the country in the year after inclusion. 9…”

The tilts, twists, and turns of torticollis

“…A recent study suggested that Klippel-Feil syndrome was present in as many as 1 in 172 births [15]. Nonsurgical management for Klippel-Feil syndrome focuses on long-term pain management [16], whereas surgery involves posterior cervical fusion. The correction of congenital scoliosis is often considered in conjunction with the surgical treatment of Klippel-Feil syndrome [16].…”