Minimally Invasive Transforaminal Lumbar Interbody Fusion and Unilateral Fixation for Degenerative Lumbar Disease

Abstract

Objective: To evaluate the clinical effect of the minimally invasive transforaminal lumbar interbody fusion combined with posterolateral fusion and unilateral fixation using a tubular retractor in the management of degenerative lumbar disease.

Methods: A retrospective analysis was conducted to analyze the clinical outcome of 58 degenerative lumbar disease patients who were treated with minimally invasive transforaminal lumbar interbody fusion combined with posterolateral fusion and unilateral fixation during December 2012 to January 2015. The spine was unilaterally approached through a 3.0-cm skin incision centered on the disc space, located 2.5 cm lateral to the midline, and the multifidus muscles and longissimus dorsi were stripped off. After transforaminal lumbar interbody fusion and posterolateral fusion the unilateral pedicle screw fixation was performed. The visual analogue scale (VAS) for back and leg pain, the Oswestry disability index (ODI), and the MacNab score were applied to evaluate clinical effects. The operation time, peri-operative bleeding, postoperative time in bed, hospitalization costs, and the change in the intervertebral height were analyzed. Radiological fusion based on the Bridwell grading system was also assessed at the last follow-up. The quality of life of the patients before and after the operation was assessed using the short form-36 scale (SF-36).

Results: Fifty-eight operations were successfully performed, and no nerve root injury or dural tear occurred. The average operation time was 138 ± 33 min, intraoperative blood loss was 126 ± 50 mL, the duration from surgery to getting out of bed was 46 ± 8 h, and hospitalization cost was 1.6 ± 0.2 ten thousand yuan. All of the 58 patients were followed up for 7-31 months, with an average of 14.6 months. The postoperative VAS scores and ODI score were significantly improved compared with preoperative data (P < 0.05). The evaluation of the MacNab score was excellent in 41 patients, good in 15, and fair in 2, suggesting an effective rate of 96.6%. The intervertebral height had reduced 0.2 ± 1.2 mm by the last follow-up, and there were 55 Grade I and II cases based on the Bridwell evaluation criterion. The fusion rate was 94.8%, and no screw breakage and loosening occurred. The scores of physical pain, general health, social, and emotional functioning were significantly increased at the last follow-up.

Conclusion: Minimally invasive transforaminal lumbar interbody fusion combined with posterolateral fusion and unilateral fixation provide a new choice for degenerative lumbar disease, and the short-term clinical outcome is satisfactory.

Keywords: Fusion rate; Lumbar degenerative disease; Lumbar interbody fusion; Posterolateral fusion; Unilateral pedicle screw fixation.

Figure 1

The cross‐section diagram of lumbar applying outspread channel. The multifidus muscles and longissimus dorsi were stripped off. After making an approach between those muscles, a tubular retractor was placed on the lamina and the facet joint.

Figure 2

Intraoperative images of the working channel. (A) The inferior articular facet and the upper half of the superior articular facet were removed. (B) Two Kirschner wires were used to drag the nerve root to the middle, to prevent nerve injury during the decompression.

Figure 3

The patient (57 years old, female) had bilateral lower limb symptoms, which were treated with unilateral incision stealth bilateral intraoperative spinal canal decompression, and the myelography showed that the dural sac and nerve root contrast filling was good, without obvious press signs. It was not necessary to perform lateral incision decompression.

Figure 4

Diagram of bone grafting. The bone grafting funnel was used to graft autogenous spongy bone and then the cortical iliac blocks were implanted.

Figure 5

Clinical imaging from one representative patient (male, 56 years old) who complained of lumbago and left lower limb extremity pain for approximately 6 months. (A) X‐ray images of lumbar vertebrae anteroposterior and lateral position plain films showed no vertebral olisthy. (B) T2‐weighted sagittal (left) and axial (right) preoperative magnetic resonance images (MRI) of the lumbar spine showed the L₅–S₁ disc herniation. (C) The X‐ray imaging indicated that the location of the internal fixator was excellent. (D) The lumbar vertebrae CT indicates that the location of the grafting bone block with intervertebral space was fine, and the synostosis of intervertebral space was also excellent.