Demographics, presentation and symptoms of patients with Klippel-Feil syndrome: analysis of a global patient-reported registry.

Klippel-Feil syndrome (KFS) occurs due to failure of vertebral segmentation during development. Minimal research has been done to understand the prevalence of associated symptoms. Here, we report one of the largest collections of KFS patient data. Data were obtained from the CoRDS registry. Participants with cervical fusions were categorized into Type I, II, or III based on the Samartzis criteria. Symptoms and comorbidities were assessed against type and location of fusion. Seventy-five patients (60F/14M/1 unknown) were identified and classified as: Type I, n = 21(28%); Type II, n = 15(20%); Type III, n = 39(52%). Cervical fusion by level were: OC-C1, n = 17(22.7%), C1-C2, n = 24(32%); C2-C3, n = 42(56%); C3-C4, n = 30(40%); C4-C5, n = 42(56%); C5-C6, n = 32(42.7%); C6-C7, n = 25(33.3%); C7-T1, n = 13(17.3%). 94.6% of patients reported current symptoms and the average age when symptoms began and worsened were 17.5 (± 13.4) and 27.6 (± 15.3), respectively. Patients reported to have a high number of comorbidities including spinal, neurological and others, a high frequency of general symptoms (e.g., fatigue, dizziness) and chronic symptoms (limited range of neck motion [LROM], neck/spine muscles soreness). Sprengel deformity was reported in 26.7%. Most patients reported having received medication and invasive/non-invasive procedures. Multilevel fusions (Samartzis II/III) were significantly associated with dizziness (p = 0.040), the presence of LROM (p = 0.022), and Sprengel deformity (p = 0.036). KFS is associated with a number of musculoskeletal and neurological symptoms. Fusions are more prevalent toward the center of the cervical region, and less common at the occipital/thoracic junction. Associated comorbidities including Sprengel deformity may be more common in KFS patients with multilevel cervical fusions. These slides can be retrieved under Electronic Supplementary Material.