Prospective Study of Posterior Lumbar Interbody Fusion With Either Interbody Graft or Interbody Cage in the Treatment of Degenerative Spondylolisthesis.

Study design: A prospective study of 2 different fusion techniques for the treatment of single-level degenerative spondylolisthesis.

Objective: To determine whether the addition of an intervertebral cage improves the clinical outcome and fusion rate of patients undergoing posterior lumbar interbody fusion (PLIF) after decompression for degenerative spondylolisthesis.

Summary of background data: The surgical approach that should be used for degenerative spondylolisthesis is a controversial issue. Decompression and PLIF with an interbody cage is widely used. Theoretical advantages in favor of PLIF include anterior column support, indirect foraminal decompression, restoration of lordosis, and reduction of the slip via ligamentotaxis. Despite numerous publications, the scientific support for the PLIF method is, however, weak.

Materials and methods: A prospective study was carried out including 59 patients with degenerative spondylolisthesis. Average age of patients was 66 years: 34 males and 25 females. Patients were divided into 2 treatment groups: group 1-32 patients with PLIF with interbody graft and group 2-27 patients with PLIF with cage. Minimum 2-year follow-up. Outcomes were assessed by measuring preoperative and postoperative lordotic angles. SF-12 physical and mental health scores were recorded along with visual analogue scores for pain. Complications were also recorded.

Results: No significant difference in the postoperative lordotic angles was achieved between the 2 techniques. Nonsignificant difference in the clinical outcomes between both the techniques.

Conclusions: We have found the use of a cage to achieve lumbar interbody fusion in the treatment of degenerative lumbar spondylolisthesis does not confer any significant advantages in terms of restoration of lumbar lordosis, improvement in clinical symptoms, or relief of pain postoperatively.