TRANSFORAMINAL LUMBAR INTERBODY FUSION: PROSPECTIVE ANALYSIS OF 20 CASES

Abstract

Purpose: Circumferential arthrodesis of the lumbar spine is necessary in certain selected situations (lumbar stenosis with instability and preserved disc height or spondylolisthesis). Posterior lumbar interbody fusion (PLIF) raises the risk of significant bleeding and fibrosis around the roots as well as neurological complications. Transforaminal lumbar interbody fusion (TLIF) can avoid excessive bleeding and root displacement. The cages are inserted via a unilateral approach.

Material and methods: This prospective single-centre study included twenty patients (nine men and eleven women), mean age 49 years. Indications for lumbar surgery were degenerative spondylolisthesis in nine patients and discal lumbar pain with foraminal stenosis in five. The clinical status was assessed with the Oswestry score, SF-36 and a visual analogue scale (VAS). Radiological assessment was based on inter-body fusion, segmentary lordosis, and lumbopelvic parameters. TLIF was associated with a posterior approach for insertion of titanium pedicular screws (CDH, Medtronic Sofamor Danek). Temporary unilateral distraction opened the foramen. Unilateral arthrectomy enabled a lateral approach to the disc without involving the roots and avoiding any movement of the dural sac. The disc was resected and the body endplates were prepared before introducing two cages (pyramesh) filled with macroporous ceramic granules (BCP) mixed with autologous bone marrow. Installation to two contourned rods enabled segmentary compression to stabilise the cages in association with posterolateral fusion.

Results: Mean operative time was three hours. Mean blood loss was 400 ml. The patients were verticalised on day three without a corset. Mean follow-up was six months with retrospective evaluation of the Oswestry score, SF-36, and VAS. Postoperative pain resolved rapidly. Two patients developed transient incomplete L5 deficit. Bony bridges around the cases and posterolaterally were identified on the six-month x-rays. Spine view confirmed the quality of the fusion and lumbopelvic parameters revealed restoration of segmentary lordosis.

Conclusion: The unilateral approach for TLIF is a reliable technique which does not compromise the roots. It enables very reliable primary stability and recovery of local segmentary lordosis. We are developing a minimally invasive percutaneous technique for this procedure.