Cervical disc arthroplasty for Klippel-Feil syndrome

Abstract

Objective: Klippel-Feil syndrome (KFS) is a congenital musculoskeletal condition characterized by improper segmentation of the cervical spine. This study aimed to evaluate outcomes of KFS patients who underwent cervical disc arthroplasty (CDA).

Methods: Consecutive patients who underwent anterior cervical surgery were retrospectively reviewed. Those patients with KFS who received discectomy adjacent to the congenitally fused vertebral segments were extracted and grouped into either the fusion or the CDA group. Clinical and radiological evaluations included visual analog scales, Neck Disability Index (NDI), Japanese Orthopedic Association (JOA) scores, C2-7 range of motion (ROM), C2-7 Cobb angle, C2-7 sagittal vertical axis (SVA), and T1-slope.

Results: Among 2320 patients, there were 41 with KFS (prevalence = 1.77%), who were younger than the entire cohort (53.3 vs 56.4 years). Thirty KFS patients had adjacent discs and were grouped into the CDA and fusion groups (14 vs 16). Type-I KFS with C3-4 involvement was the most common for both groups (92.8% vs 81.2% with 57% vs 50%, respectively). Post-operation, both groups demonstrated improvement of all the patient reported outcomes. The C2-7 ROM significantly decreased in the fusion group than that of pre-operation (12.8 ± 6° vs 28.1 ± 11.5°). In contrast, the CDA group successfully preserved C2-7 and segmental ROM without additional complications.

Conclusions: KFS is rare (prevalence = 1.77%) among cervical spine surgery patients, and it rarely affects the overall cervical spinal alignment, except that it decreases segmental mobility. CDA is a feasible option for KFS because it not only avoids long-segment fusion but also preserves segmental and global mobility.

Keywords: Anterior cervical discectomy and fusion; Cervical disc arthroplasty; Klippel-Feil syndrome; Range of motion; Segmental mobility.