Circumferential Fusion through All-Posterior Approach in Andersson Lesion

Study DesignRetrospective case series.PurposeTo assess safety and efficacy of single stage, posterior stabilisation and anterior cage reconstruction through the transforaminal or lateral extra-cavitary route for Andersson lesions.Overview of LiteraturePseudoarthrosis in ankylosing spondylitis (Andersson lesion, AL) can cause progressive kyphosis and neurological deficit. Management involves early recognition and surgical stabilisation in patients with instability. However, the need and safety of anterior reconstruction of the vertebral body defect remains unclear.MethodsTwenty consecutive patients with AL whom presented with instability back pain and or neurological deficit were managed by single stage posterior approach with long segment pedicle screw fixation and anterior vertebral reconstruction. Radiological evaluation included- the regional kyphotic angle, measurement of anterior defect in computed tomography (CT) scan and the spinal cord status in magnetic resonance imaging. Radiological outcomes were assessed for fusion and kyphosis correction. Functional outcomes were assessed with visual analogue scale (VAS), ankylosing spondylitis quality of life (ASQoL) and Oswestry disability index (ODI).ResultsThe mean age of the patients was 50.1 years (male, 18; female, 2). The levels affected include thoracolumbar (n=12), lower thoracic (n=5) and lumbar (n=3) regions. The mean level of fixation was 6.2±2.4 vertebrae. The mean anterior column defect was 1.6±0.6 cm. The mean surgical duration, blood loss and hospital stay were 112 minutes, 452 mL and 6.2 days, respectively. The mean followup was 2.1 years. At final follow up, VAS for back pain improved from 8.2 to 2.4 while ODI improved from 62.7 to 18.5 (p