The aim of this study is to introduce and investigate the efficacy
and feasibility of a new vertebral osteotomy technique, vertebral
column decancellation (VCD), for rigid thoracolumbar kyphotic deformity
(TLKD) secondary to ankylosing spondylitis (AS). We took 39 patients from between January 2009 and January 2013
(26 male, 13 female, mean age 37.4 years, 28 to 54) with AS and
a TLKD who underwent VCD (VCD group) and compared their outcome
with 45 patients (31 male, 14 female, mean age 34.8 years, 23 to
47) with AS and TLKD, who underwent pedicle subtraction osteotomy
(PSO group), according to the same selection criteria. The technique
of VCD was performed at single vertebral level in the thoracolumbar
region of AS patients according to classification of AS kyphotic
deformity. Pre- and post-operative chin-brow vertical angle (CBVA),
sagittal vertical axis (SVA) and sagittal Cobb angle in the thoracolumbar
region were reviewed in the VCD and PSO groups. Intra- , post-operative
and general complications were analysed in both group.Aims
Patients and Methods
We report five children who presented at the mean age of 1.5 years (1.1 to 1.9) with a progressive thoracolumbar kyphosis associated with segmental instability and subluxation of the spine at the level above an anteriorly-wedged hypoplastic vertebra at L1 or L2. The spinal deformity appeared to be developmental and not congenital in origin. The anterior wedging of the vertebra may have been secondary to localised segmental instability and subsequent kyphotic deformity. We suggest the term ‘infantile developmental thoracolumbar kyphosis with segmental subluxation of the spine’ to differentiate this type of deformity from congenital displacement of the spine in which the congenital vertebral anomaly does not resolve. Infantile developmental kyphosis with segmental subluxation of the spine, if progressive, may carry the risk of neurological compromise. In all of our patients the kyphotic deformity progressed over a period of three months and all were treated by localised posterior spinal fusion. At a mean follow-up of 6.6 years (5.0 to 9.0), gradual correction of the kyphosis was seen on serial radiographs as well as reconstitution of the hypoplastic wedged vertebra to normality. Exploration of the arthrodesis was necessary at nine months in one patient who developed a pseudarthrosis.
