MAGNETIC RESONANCE IMAGING IN FAILED BACK SURGERY SYNDROME.

The failed back surgery syndrome (FBSS) is a severe, long-lasting, disabling and relatively frequent (5-10%) complication of lumbosacral spine surgery. Wrong level surgery, inadequate surgical techniques, vertebral instability, recurrent disc herniation, and lumbosacral fibrosis are the most frequent causes of FBSS. The results after repeated surgery on recurrent disc herniations are comparable to those after the first intervention, whereas repeated surgery for fibrosis gives only 30-35% success rates, and 15-20% of the patients report worsening of the symptoms. MRI has allowed a differentiation between these two pathologies for selection of different therapies. Gadolinium enhanced MR is at present the single most sensitive and specific imaging modality available to the neuro radiology imager for the evaluation of the post operative lumbosacral spine in the patient presenting with FBSS. Medical imaging specialists and clinicians need to better understand the origins and means of avoiding the FBSS, to more clearly focus the post operative imaging evaluation and to more successfully link the clinical diagnosis and the imaging findings with optimised patient therapy.