Transforaminal lumbar interbody fusion: a safe technique with satisfactory three to five year results

Abstract

The unilateral transforaminal approach for lumbar interbody fusion as an alternative to the anterior (ALIF) and traditional posterior lumbar interbody fusion (PLIF) combined with pedicle screw instrumentation is gaining in popularity. At present, a prospective study using a standardized tool for outcome measurement after the transforaminal lumber interbody fusion (TLIF) with a follow-up of at least 3 years is not available in the current literature, although there have been reports on specific complications and cost efficiency. Therefore, a study of TLIF was undertaken. Fifty-two consecutive patients with a minimum follow-up of 3 years were included, with the mean follow-up being 46 months (36--64). The indications were 22 isthmic spondylolistheses and 30 degenerative disorders of the lumbar spine. Thirty-nine cases were one-level, 11 cases were two-level, and two cases were three-level fusions. The pain and disability status was prospectively evaluated by the Oswestry disability index (ODI) and a visual analog scale (VAS). The status of bony fusion was evaluated by an independent radiologist using anterior-posterior and lateral radiographs. The operation time averaged 173 min for one-level and 238 min for multiple-level fusions. Average blood loss was 485 ml for one-level and 560 ml for multiple-level fusions. There were four serious complications registered: a deep infection, a persistent radiculopathy, a symptomatic contralateral disc herniation and a pseudarthrosis with loosening of the implants. Overall, the pain relief in the VAS and the reduction of the ODI was significant (P<0.05) at follow-up. The fusion rate was 89%. At the latest follow-up, significant differences of the ODI were neither found between isthmic spondylolistheses and degenerative diseases, nor between one- and multiple-level fusions. In conclusion, the TLIF technique has comparable results to other interbody fusions, such as the PLIF and ALIF techniques. The potential advantages of the TLIF technique include avoidance of the anterior approach and reduction of the approach related posterior trauma to the spinal canal.

Figures

Fig. 1

a In order to approach the neuroforamen and the posterolateral part of the disc it is necessary to remove the facet joint. The osteotomies are marked by the broken lines. b The disc can be removed from the gap between the nerve root of the upper segment and the dura after bipolar coagulation of epidural veins. The nerve root should not be retracted to minimize the risk of postoperative radicular pain

Fig. 2

a The specially designed curved cage for the transforaminal interbody fusion (micomed Ortho, Switzerland) is available in different sizes and has a lordotic profile of 5°. b The introducer is connected in a 40° angle to enable cage positioning using the transforaminal approach to the disc space

Fig. 3

a Lateral preoperative radiograph of a patient with an isthmic spondylolisthesis L5/S1 grade I. b Anterior–posterior and c lateral radiographs 2 years after pedicle screw instrumentation and TLIF L5/S1. Please note the bony fusion in the anterior part of the disc space

Fig. 4

Results on pain evaluation by VAS between 0 (no pain) and 10 (maximal pain), preoperatively (preop.) and during the follow-up period (latest follow-up between 36 and 64 months (mo. months postoperatively). All postoperative values are significantly lower compared with preoperative (P<0.05)

Fig. 5

Results on functional outcome measurement by ODI (%) preoperatively (preop.) and during follow-up (latest latest follow-up between 36 and 64 months (mo. months postoperatively). All postoperative values are significantly lower compared with preoperative (P<0.05)