Study design: A retrospective study.
Objectives: To address the role of congenitally fused cervical segments, the degree of cervical scoliosis, and other risk factors on the presence of Sprengel's deformity (SD) in young patients with Klippel-Feil syndrome (KFS).
Summary of background data: Numerous abnormalities are associated with KFS, one of the most common being SD. It has been postulated that more severe forms of KFS may be more associated with extraspinal manifestations, such as SD.
Methods: Thirty KFS patients from a single institution were reviewed. Cervical neutral lateral/dynamic/anteroposterior and thoracic anteroposterior plain radiographs were assessed. Radiographically, occipitalization (O-C1), number of congenitally fused segments (C1-T1), classification type (Types I-III), degree of cervical scoliosis, and the presence of SD was assessed. Clinical chart review entailed patient demographics and evidence of the clinical assessment of SD. The threshold for statistical significance was P < 0.05.
Results: There were 11 males (36.7%) and 19 females (63.3%) with a mean age of 13.5 years (range, 2.7-26.3 years). Occipitalization was present in 10 (33.3%) individuals and C2-C3 was the most common level fused (70.0%). The mean number of congenitally fused segments was 3.3 (range, 1-6 levels). The mean degree of cervical scoliosis was 17.3 degrees (range, 0 degrees-67 degrees). There were 6 (20%) Type I, 15 Type II (50.0%), and 9 Type III (30%) patients. SD was noted in 5 (16.7%) of the patients. Four patients had unilateral, whereas 1 patient had bilateral SD. There was 4.0 and 3.1 mean number of congenitally fused segments in patients with or without SD, respectively. SD did not occur in Type I patients (single fused block). The presence of SD was found to be nonsignificant regarding sex type (P = 0.327), presence of occipitalization (P = 0.300), number of congenitally fused segments (P = 0.246), specific congenitally fused segments (P > 0.05), classification type (P > 0.05), and scoliosis (P = 0.702).
Conclusion: SD occurred in 16.7% of KFS patients. Sex type, number of congenitally fused segments, specific fused patterns, occipitalization, classification type, and the degree of cervical scoliosis did not seem to be significantly associated with the presence of SD in KFS patients in our series. Thorough examination for the presence and degree of SD in KFS is necessary, irrespective of the extent of cervical abnormalities. Alternatively, the treating physician should not dismiss a thorough cervical spine examination in patients with SD, evaluating factors that may predispose the KFS patient to an increased risk of neurologic injury.