Purpose: Lumbar interbody fusion cages is a valid technique in the treatment of disc diseases. The aim of this study is to evaluate its validity through the analysis of clinical outcomes and radiological findings.

Materials and methods: The paper reports a serie of 52 posterior lumbar interbody fusion cages operations. Clinical outcomes and radiological results were evaluated at a mean of 5 years post-surgery.

Results: Outcome analysis showed a gradual improvement in symptoms. After surgery, the majority of patients returned to their normal activities. Follow-up plain roentgenograms showed no loss of disc height and no signs of implant’s looseness. Computed Tomography (CT) scans showed the presence of mineralized autologous bone grafts inside the interbody cages.

Conclusions: Expandable interbody cages allow the restoration of the disc space height, giving support to the anterior column, opening the neuroforaminal area and providing increased stability. The interpretation of fusion on the basis of roentgenograms is subjected to arguement. Thin CT scan offers more information than X-rays about the fusion process.