Aims

High-grade dysplastic spondylolisthesis is a disabling disorder for which many different operative techniques have been described. The aim of this study is to evaluate Scoliosis Research Society 22-item (SRS-22r) scores, global balance, and regional spino-pelvic alignment from two to 25 years after surgery for high-grade dysplastic spondylolisthesis using an all-posterior partial reduction, transfixation technique.

Acute angulation at the thoracolumbar junction with segmental subluxation of the spine occurring at the level above an anteriorly hypoplastic vertebra in otherwise normal children is a rare condition described as infantile developmental thoracolumbar kyphosis. Three patient series with total of 18 children have been reported in the literature. We report five children who presented with thoracolumbar kyphosis and discuss the treatment algorithm. We reviewed the medical records and spinal imaging at initial clinical presentation and at minimum two-year follow-up. The mean age at presentation was eight months (two to 12). All five children had L2 anterior vertebral body hypoplasia. The kyphosis improved spontaneously in three children kept under monitoring. In contrast, the deformity was progressive in two patients who were treated with bracing. The kyphosis and segmental subluxation corrected at latest follow-up (mean age 52 months; 48 to 60) in all patients with near complete reconstitution of the anomalous vertebra. The deformity and radiological imaging on a young child can cause anxiety to both parents and treating physicians. Diagnostic workup and treatment algorithm in the management of infantile developmental thoracolumbar kyphosis is proposed. Observation is indicated for non-progressive kyphosis and bracing if there is evidence of kyphosis and segmental subluxation deterioration beyond walking age. Surgical stabilisation of the spine can be reserved for severe progressive deformities unresponsive to conservative treatment.

Cite this article: Bone Joint J 2015;97-B:982–7.

Introduction

Growing rods are used in the treatment of early-onset scoliosis. The aim of this technique is to achieve deformity correction while maintaining spinal growth. Gradual stiffening or spontaneous fusion of the spine can interfere with the ability to lengthen. Furthermore, diminished acquired length with serial distraction is common and needs to be evaluated and quantified. The purpose of this prospective study was to measure the forces and amount of distraction over time in patients with early-onset scoliosis treated with growing rods.

We describe the results of a prospective case series to evaluate a technique of direct pars repair stabilised with a construct that consists of a pair of pedicle screws connected with a u-shaped modular link that passes beneath the spinous process. Tightening the link to the screws compresses the bone grafted pars defect providing rigid intrasegmental fixation. 20 patients aged between 9 and 21 years with a pars defect at L5 confirmed on computed tomography (CT) were included. The average age of the patients was 13.9 years. The eligible patient had Grade I or less spondylolisthesis and no evidence of intervertebral degeneration on MRI. The average duration of follow-up was 4 years. Clinical assessments for all patients was via the Oswestry disability index (ODI) and visual analogue scores (VAS). At the latest follow-up, 18 of the 20 patients had excellent clinical outcomes with a significant (p<0.001) improvement in their ODI and VAS scores with a mean post-operative ODI score of 8%. Fusion of the pars defect as assessed by CT showed fusion rates of 80%. There were no hardware complications. The strength of the construct obviates the need for post-operative immobilisation.

We describe the results of a prospective case series of patients with spondylolysis, evaluating a technique of direct stabilisation of the pars interarticularis with a construct that consists of a pair of pedicle screws connected by a U-shaped modular link passing beneath the spinous process. Tightening the link to the screws compresses bone graft in the defect in the pars, providing rigid intrasegmental fixation. We have carried out this procedure on 20 patients aged between nine and 21 years with a defect of the pars at L5, confirmed on CT. The mean age of the patients was 13.9 years (9 to 21). They had a grade I or less spondylolisthesis and no evidence of intervertebral degeneration on MRI. The mean follow-up was four years (2.3 to 7.3). The patients were assessed by the Oswestry Disability Index (ODI) and a visual analogue scale (VAS). At the latest follow-up, 18 patients had an excellent clinical outcome, with a significant (p < 0.001) improvement in their ODI and VAS scores. The mean ODI score at final follow-up was 8%. Assessment of the defect by CT showed a rate of union of 80%. There were no complications involving the internal fixation.

The strength of the construct removes the need for post-operative immobilisation.