Though recommended some years ago by Cloward, PLIF (posterior lumbar interbody fusion) was not widely used for many years. Recently many authors have recognised PLIF as a preferred technique for lumbar stabilisation. Preservation or re-establishment of disc height is associated with an improved patency of the intervertebral foramen. The use of the threaded fusion cage (TFC) provides immediate stabilisation, preservation of disc height due to highly resistant material, and long term fusion with autogenous bone. The instrumentation, designed in association with the cage, provides a safe environment for the neural structures during the procedure. It also makes the procedure more reproducible and less dependent on the operator. The learning curve for doing the operation is rapid. Using the Prolo scale, on the economic and functional scales, 83% of cases were rated good to excellent. The fusion rate was 94% at one year.