Treatment of Basilar Invagination With Klippel-Feil Syndrome: Atlantoaxial Joint Distraction and Fixation With Transoral Atlantoaxial Reduction Plate

BACKGROUND: Klippel-Feil syndrome (KFS) is characterized by congenital vertebral fusion of the cervical spine and a wide spectrum of associated anomalies. In patients with KFS with basilar invagination (BI), compression of the brainstem and upper cervical cord results in neurological deficits, and decompression and occipitocervical reconstruction are required. The highly varied anatomy of KFS makes a posterior occipitocervical fixation strategy challenging. For these patients, the transoral atlantoaxial reduction plate (TARP) operation is an optimal option to perform a direct anterior fixation to achieve stabilization. OBJECTIVE: To evaluate the effectiveness of TARP internal fixation for the treatment of BI with KFS. METHODS: Ten consecutive patients with BI and KFS who underwent TARP reduction and fixation from 2010 to 2012 were reviewed. Clinical assessment and image measurements were performed preoperatively and at the most recent follow-up. Nine patients (9/10) were followed for an average of 31.44 months. RESULTS: Symptoms were alleviated in 9 of 9 patients (100.00%). The odontoid process was ideally corrected with the TARP system. The mean clivus canal angle improved from 124 preoperatively to 152 postoperatively. The average preoperative and postoperative Japanese Orthopedic Association scores were 10.56 (n = 9) and 14.67 (n = 9), respectively, indicating 63.82% improvement. There was bony bridge catenation on the computed tomography scans and no evidence of hardware failure at 6 months. CONCLUSION: The TARP operation is effective and safe for treating patients with BI with KFS. The midterm clinical results were satisfactory.