To investigate the operating strategies and essentials of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) with tubular channel (Spotlight) to treat single-level lumbar degenerative diseases.

From November 2013 to December 2015, 97 patients (47 males and 50 females) underwent single-level lumbar degenerative diseases following MIS-TLIF with Spotlight were analyzed, whose age were from 35-82 years old with the average age of 57.6±12.3 years old. The preoperative diagnosis was lumbar spinal stenosis in 63 cases, lumbar spondylolisthesis in 25 cases, and lumbar instability in 9 cases. The affected level was L_3,4 in 9 cases, L_4,5 in 66 cases, and L₅S₁ in 22 cases. According to distinct clinical manifestations and radiological characteristics, different approaches of Spotlight channels were employed. Unilateral decompression via unilateral channel was performed in 52 cases, bilateral decompression via unilateral channel was performed in 22 cases, and bilateral decompression via bilateral channel was performed in 23 cases. Clinical outcomes included operation duration, surgical blood loss, post-operative drainage volume and complications was recorded. Average intervertebral height, lumbar and surgical Cobb angle were utilized to evaluate the reduction of intervertebral height and lumbar lordosis. The low back and leg pain were represented as Visual Analogue Scale (VAS) score. The preoperative and postoperative Oswestry Disability Index (ODI) score were recorded individually to evaluate patients’ functional recovery. Besides, the Bridwell criterion was introduced to define the extent of the lumbar fusion. The MacNab criterion was used for assessment of postoperative efficacy.

The operation duration was 189.8±41.3 min, the volume of surgical blood loss was 143.9±102.0 ml and the volume of postoperative drainage 75.0±59.0 ml in all cases. Among them, operation time was 165.0±24.2 min, surgical blood loss was 99.5±54.1 ml and postoperative drainage was 48.4±27.6 ml in the operation group of unilateral decompression via unilateral channel. The date in the group of Bilateral decompression via unilateral channel were 208.9±46.0 min, 151.4±96.3 ml, 88.0±51.3 ml and in the group of bilateral decompression via bilateral channel were 225.4±32.0 min, 236.0±126.3 ml, 122.8±81.7 ml. All the patients were followed up for 16-42 months, the average follow-up time was 24.9±7.0 months. Low back VAS reduced from 6.10±0.84 preoperatively to 1.59±0.49 at the final follow-up, leg VAS decreased from 6.56±0.85 preoperatively to 1.59±0.57 at the last follow-up, and ODI reduced from 59.36%±5.52% preoperatively to 15.89%±2.90% at the final follow-up, compared with preoperative, the differences were significant. Average intervertebral height improved from 9.92±2.25 mm preoperatively to 12.24±1.78 mm at latest follow-up time, which had statistically significant difference. Operative segment and lumbar Cobb angle were 13.81°±6.10° and 32.32°±11.97° preoperative, at the time of latest follow-up improved to 14.25°±5.57° and 35.83°±9.89°, Compared with preoperative, lumbar Cobb angle was significantly increased but operative segment Cobb had no significant difference. According to the criteria of Bridwell, intervertebral fusion at final follow-up of I and II grades were 90 cases in total (92.8%). The MacNab criteria was used to evaluate the clinical efficacy, which 69 were excellent, 23 were good, and 5 were acceptable, the excellent and good rate was 94.8%.

The technique of MIS-TLIF with the tubular channel (Spotlight) is safe and efficient for the treatment of single segment lumbar degenerative diseases. Different strategies can be selected by different preoperative clinical manifestations and radiological features.

LLumbar vertebrae; Surgical procedures, minimally invasive; Spinal fusion