Posterior lumbar interbody fusion using a unilateral single cage and a local morselized bone graft in the degenerative lumbar spine

Abstract

Background: We retrospectively evaluated the clinical and radiological outcomes of posterior lumbar interbody fusion (PLIF) with using a unilateral single cage and a local morselized bone graft.

Methods: Fifty three patients who underwent PLIF with a unilateral single cage filled with local morselized bone graft were enrolled in this study. The average follow-up duration was 31.1 months. The clinical outcomes were evaluated with using the visual analogue scale (VAS) at the pre-operative period, at 1 year post-operation and at the last follow-up, the Oswestry Disability Index, the Prolo scale and the Kim & Kim criteria at the last follow-up; the radiological outcomes were evaluated according to the change of bone bridging, the radiolucency, the instability and the disc height.

Results: For the clinical evaluation, the VAS pain index, the Oswestry Disability Index, the Prolo scale and the Kim & Kim criteria showed excellent outcomes. For the the radiological evaluation, 52 cases showed complete bone union at the last follow-up. Regarding the complications, only 1 patient had cage breakage during follow-up.

Conclusions: PLIF using a unilateral single cage filled with a local morselized bone graft has the advantages of a shorter operation time, less blood loss and a shorter hospital stay, as compared with the PLIF using bilateral cages, for treating degenerative lumbar spine disease. This technique also provides excellent outcomes according to the clinical and radiological evaluation.

Keywords: Local morselized graft; Posterior lumbar interbody fusion; Spinal fusion; Unilateral single cage.

Fig. 1

Diagrams depicting the steps of the posterior lumbar interbody fusion via a unilateral approach. (A) After the retraction of the thecal sac and the traversing nerve root to the midline, the disc material and endplates were removed as much as possible in the ipsilateral side. Before the cage insertion, the local morselized bone from the decompressed lamina, spinous process and facets was grafted as much as possible into the ipsilateral and anterior side of the intervertebral space. (B) The single cage filled with local morselized bone graft was introduced to the intervertebral space. Last, adequate impaction was performed.

Fig. 2

A 51-year old female with spinal stenosis at L4-5. (A) The preoperative lateral view shows a decreased disc height at L4-5. (B) The lateral view after surgery shows restoration of the disc height. (C) At 3 year after surgery, the lateral radiograph shows solid fusion and maintenance of reduction.

Fig. 3

A 71 year-old male who presented with lower back pain and motor weakness. (A) The lateral radiograph shows disc space narrowing on L3-4-5 and degenerative kyphosis. (B) The posterior lumbar interbody fusion with a single cage and a transpedicular instrument was performed and the follow-up radiograph shows maintenance of the disc height and restoration of lordosis. (C) At 3 years after surgery, the lateral radiograph shows solid fusion and maintainance of the reduction.

Fig. 4

A 53 year-old female who presented with a 1-year history of lower back pain and radiating right leg pain. (A) The lateral radiograph shows spondylolisthesis on L3-4. (B) The lateral view after surgery shows restoration of the disc height. (C) The last follow-up radiograph shows breakage of the cage, but the disc space was maintained and there is probable bone bridging without radiolucency and with stability on the flexion and extension views.

Fig. 5

Changes of the disc height according to the preoperative, immediate postoperative and last follow-up.