Revision Transforaminal Lumbar Interbody Fusion

Introduction

Degenerative disease of the lumbar spine has increased with the aging population and the number of elective lumbar spinal surgeries has also increased. Concurrently, the number of revision lumbar spinal surgeries has also increased as patients experience recurrence of symptoms or develop adjacent segment disease after their initial surgery. The transforaminal lumbar interbody fusion (TLIF) was developed as a technique to obtain an interbody fusion through a posterolateral approach with less manipulation of the thecal sac and nerve roots. The transforaminal approach achieves this by providing a trajectory into the disc space through Kambin’s triangle in the axilla of the exiting nerve root.

A failed TLIF may require salvage surgery when the patient develops new or recurrent symptoms. A thorough physical examination and history are helpful in assessing potential causes of recurrent or persistent pain after a previous lumbar surgery. Given that revision surgery has been shown to improve health-related quality-of-life outcomes, it is essential to identify those patients whose TLIFs have not fused and offer them a revision surgery. For example, mechanical back pain shortly after a previous lumbar fusion surgery may be indicative of a migrated cage. Moreover, nonmechanical back pain with constitutional symptoms such as fever, weight loss, or chills shortly after a previous fusion surgery may indicate a surgical site infection that could involve the interbody cage. Also, recurrent pain or new progressive weakness several months to years after an initial lumbar fusion surgery may indicate pseudarthrosis or adjacent segment stenosis. In this chapter, we will discuss methods to salvage a failed TLIF and discuss how TLIF can be used to treat progressive spinal disease after a previous lumbar surgery.

Pseudarthrosis, Subsidence, and Cage Migration

An interbody cage inserted through a transforaminal corridor via Kambin’s triangle is typically smaller than cages placed via an anterior or lateral approach. Thus TLIF cages may result in pseudarthrosis or subsidence of the cage into the adjacent endplates of the vertebrae. Common causes for TLIF failure are undersized cages, subsidence of a cage into the end-plate, posterior cage migration into a nerve root or the thecal sac, and pseudarthrosis. Various approaches can be used to revise and salvage the failed TLIF level, including an anterior approach, a posterior-only approach, and a lateral approach. All approaches aim to remove or reposition the previously placed cage, increase disc and foraminal height to decompress the exiting nerve roots, and increase the likelihood of fusion of the revised segment.