A variation on a PLIF where the graft is placed from one side (via the neural foramen) after complete removal of the facet joint on that side. Requires much less nerve root retraction than PLIF, and is often adventageous for re-operations with primarly unilateral pathology where going through the foramen avoids the scar tissue.
Since its initial description by Harms and Rolinger in 1982, 1) transforaminal lumbar interbody fusion (TLIF) has been used with high rates of success in patients who present with instability or deformity 2).
Open transforaminal lumbar interbody fusion (TLIF) using transpedicular rods and interbody cage, is associated with a significant paravertebral muscle and ligament injury.
The TLIF procedure described by Jürgen Harms was a new modification and minimized complications of lumbar fusions and reduced the invasiveness of the procedure.
Nowadays a wide variety of implants and implantation techniques are available, making interbody fusions in PLIF and TLIF techniques safe and successful procedures 3).
Surgical hardware is applied to the spine to help enhance the fusion rate. Pedicle screws and rods are attached to the back of the vertebra and an interbody fusion spacer is inserted into the disc space from one side of the spine.
Bone graft is placed into the interbody space and alongside the back of the vertebra to be fused. Bone graft is obtained from the patient's pelvis, although bone graft substitutes are also sometimes used. As the bone graft heals, it fuses the vertebra above and below and forms one long bone.
Open transforaminal lumbar interbody fusion (Open-TLIF).
Transforaminal lumbar interbody fusion (TLIF) with bilateral facetectomy (BF) versus unilateral facetectomy (UF).
MIS-TLIF is a safe and viable option for lumbar fusion in morbidly obese patients, and when compared to open-TLIF, resulted in similar improvement in pain and functional disability. Post-operative complications rates between both cohorts were also not significantly divergent 4).
MI-TLIF is associated with reduced blood loss, decreased length of stay, decreased complication rates, and increased radiation exposure. The rates of fusion and operative time are similar between MI-TLIF and O-TLIF. Differences in long-term outcomes in MI-TLIF vs O-TLIF are inconclusive and require more research, particularly in the form of large, multi-institutional prospective randomized controlled trials 5).
Patients treated with MIS TLIF have less need for post-operative blood transfusion, decreased post-operative back pain, and shorter hospital admission time than those treated by open TLIF techniques 6) 7) 8).
Patients who underwent MiTLIF were exposed to 2.4-fold more radiation than those who underwent OTLIF. Although the theoretical cancer risk associated with radiation exposure may be tolerable, stochastic effects should not be disregarded 14).
Stand alone TLIF may be associated with progressive lumbar spondylolisthesis at that level and are usually supplemented with pedicle screw/rod.
A retrospective review was performed on 125 consecutive patients who underwent minimally invasive transforaminal lumbar interbody fusion and transpedicular screws placement between the levels of T-12 and S-1. Screw accuracy was evaluated using a postoperative computed tomography by three independent observers. Pedicle breach was documented when there was a violation in any direction of the pedicle. Inter-observer agreement was assessed with the Kappa coefficient.
A total of 470 transpedicular screws were evaluated between the levels of T-12 and S-1. In 57 patients the instrumentation was bilateral and in 68 unilateral. A substantial degree of agreement was found between the observers AB (κ=0.769) and A-C (κ=0.784) and almost perfect agreement between observers B-C (κ=0.928). There were a total of 427.33 (90.92%) screws without breach, 39.33 (8.37%) minor breach pedicles and 3.33 (0.71%) major breach pedicles. The pedicle breach rate was 9.08% Trajectory pedicle breach percentages were as follows: minor medial pedicle breach 4.68%, minor lateral pedicle breach 3.47%, minor inferior pedicle breach 0.22%, and major medial breach 0.70%. No intraoperative instrumentation-related or postoperative clinical complications were encountered and no surgical revision was needed.
The study demonstrated a high accuracy (90.2%) for 2-D fluoroscopy-guided pedicle screw using electromonitoring. Only 0.71% of the 470 screws had a major breach. Knowing the radiological spine pedicle anatomy and the correct interpretation of EMG are the key factors for this technique 16).