[A feasibility research of minimally invasive transforaminal lumbar interbody fusion using unilateral incision and hybrid internal fixation for dural-level lumbar degenerative disease].

OBJECTIVE: To investigate the feasibility and clinical outcomes of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) using unilateral incision and internal fixation of pedicle screws and a translaminar facet screw for dural-level lumbar degenerative disease.

METHODS: Between January 2010 and January 2012, 19 patients with dural-level lumbar degenerative disease was treated, including 7 males and 12 females with an average age of 50.4 years (range, 22-68 years) and a median disease duration of 37 months (range, 8 months to 15 years). The operated segments included L3-5 in 6 cases and L4-S1 in 13 cases. MIS-TLIF was performed by unilateral incision, and then pedicle screws and a translaminar facet screw were used for internal fixation.

RESULTS: Operations were successfully performed in all cases. The mean operation time was 158 minutes; the mean intraoperative blood loss was 156 mL; the mean length of incision was 42 mm; the mean postoperative ambulation time was 35 hours; the mean hospitalization time was 4.1 days; and the mean length of translaminar facet screw was 51 mm. All the wounds healed by first intention. No complication occurred in the others except 1 case of dural tear. The patients were followed up 12-24 months (mean, 17.1 months). The visual analogue scale (VAS) scores for back and leg pain and Oswestry disability index (ODI) scores at postoperation were significantly improved when compared with preoperative ones (P < 0.05). The symptom disappeared gradually. The postoperative X-ray images showed that the internal fixations were in good position; all facets screws penetrated through the base of spinous process, laminar, and facets joint; of the screws, 2 (5.3%) facets screws penetrated lateral laminar, and 1 (1.8%) pedicle screw penetrated out of pedicle of vertebral arch, but no symptom of nerve injury was seen. The CT scan and three-dimensional reconstruction at postoperative 12th month showed good interbody fusion; and based on the Bridwell's interbody fusion grading system, 11 cases were rated as grade I, and 8 cases as grade II.

CONCLUSIONS: MIS-TLIF by unilateral incision and internal fixation is a safe and reliable method to treat dural-level lumbar degenerative disease, and it has the advantages of short operation time, less invasion, less blood loss, and fast recovery.