Correction Surgeries for Severe Cervical Kyphotic Deformities with Myelopathy due to Various Etiologies

Materials and Methods: Seventeen cases with cervical kyphotic deformity due to various etiologies were operated on. Kyphosis was located at the craniovertebral junction (CVJ) and subaxial region in 13 and 4 cases, respectively. There was congenital kyposis in 10 (CVJ: 8, subaxial: 2), iatrogenic in 3 (post-laminoplasty: 2, C1/2 pseudoarthrosis: 1), post-traumatic in 1, Recklinghausen' disease in 1, post-infectious in 1, and unknown etiology in 1. In 4 subaxial kyphosis cases, pre-op. kyphotic angles were over 45 degrees (46-72, avr. 60 degrees). Pre-op. clivoaxial angles were 109-126 degrees (avr. 115 degrees) in CVJ kyphosis cases. Posterior loop/rod type instrumentations with sblaminar wires and/or pedicle screws were used in all cases. Mean follow up period was 3.2 years. (2-12.5 years). Correction status, neurological recovery evaluated by JOA score, respiratory and swallowing disturbances were examined.

Results: Kyphotic deformity was nicely corrected, and solid fusion was obtained in all cases. Average correction angle was 54 degrees (39-75) in subaxial kyphosis, and 28 degrees (14-47) in CVJ kyphosis. Respiratory problems and difficulty in swallowing improved after the surgery in all cases. Pre- and post-op. mean JOA score were 6.5 and 12, respectively.

Discussion: Interlaminar segmental decompression prior to correction was one of the key to avoid additional compression to the cord by protrusion of the ligamentum flava. In cases with the main compression factors at the CVJ, transoral anterior decompression is essentially required. We did not have the ability to do that, and instead performed posterior realignment by widening the clivo-axial angle to reduce the ventral compression to the neuroaxis using powerful posterior instrumentation. The results surpassed our expectations, and post-op. neurological improvement was obtained in all cases.