Cervical scoliosis in the Klippel-Feil patient.

STUDY DESIGN: Retrospective study.

OBJECTIVE: This study addressed in patients with Klippel-Feil syndrome (KFS), the role of congenitally fused cervical patterns, risk factors, and cervical symptoms associated with cervical scoliosis.

SUMMARY OF BACKGROUND DATA: KFS is an uncommon condition, characterized as improper segmentation of one or more cervical spine segments with or without associated spinal or extraspinal manifestations. "Scoliosis" is potentially the most common manifestation associated with KFS. However, the role of congenitally fused cervical patterns along with additional potential risk factors and their association with cervical scoliosis, and its relationship with cervical spine-related symptoms remain largely unknown.

METHODS: Plain radiographs were utilized to assess the location of congenitally fused cervical segments (O-T1), degree of coronal cervical alignment, and any additional cervical and thoracic spine abnormalities. The classification scheme, as proposed by Samartzis et al of congenitally fused cervical patterns (Types I-III) in KFS patients, was utilized and additional fusion and region-specific patterns were assessed. Patients with coronal cervical alignments of 10° or greater were regarded scoliotic. Patient demographics and the presence of cervical spine-related symptoms were also assessed.

RESULTS: Thirty KFS patients were assessed (mean age, 13.5 yr). The mean coronal cervical alignment was 18.7° and scoliosis was noted in 16 patients. Patients that exhibited congenital fusion of the mid and lower cervical spine region, had multiple, contiguous congenitally fused segments (Type III), and associated vertebral malformations (e.g., hemivertebrae) were highly associated with the presence of cervical scoliosis (P < 0.05). Ten patients exhibited cervical spine-related symptoms; however, no statistically significant difference was noted between the presence of symptoms and coronal cervical alignment (P = 0.815) and cervical scoliosis (P = 0.450).

CONCLUSION: The study noted a prevalence of cervical scoliosis to occur in 53.3% of young KFS patients. Such patients that exhibited congenital fusion of the mid and lower cervical spine region, had multiple, contiguous congenitally fused segments (Type III), and associated vertebral malformations (e.g., hemivertebrae) were highly associated with the presence of cervical scoliosis. However, in young KFS patients, the presence of cervical scoliosis may not be associated with the manifestation of cervical spine-related symptoms.