A comparative study of MIDLIF and MIS-TLIF unilateral approach for bilateral decompression in the treatment of single-segment lumbar spinal stenosis

English Keywords:Lumbar spinal stenosis  Minimally invasive technology  Spinal canal decompression  Unilateral approach and bilateral decompression

English Abstract:

  【Abstract】 Objectives: To comparative the clinical efficacies of midline lumbar interbody fusion(MIDLIF) and minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) unilateral approach bilateral decompression in the treatment of single-segment lumbar spinal stenosis(LSS). Methods: A retrospective analysis was made on 44 LSS patients with bilateral symptoms treated with MIDLIF and MIS-TLIF unilateral approach bilateral decompression in the Department of Orthopedics of our hospital from January 2017 to January 2020, involving 2 cases of L3-4, 41 cases of L4-5, and 1 case of L5-S1. Among the patients, 21 received MIDLIF operation(MIDLIF group) and 23 received MIS-TLIF unilateral approach bilateral decompression operation(MIS-TLIF group). There was no statistical difference between the two groups in follow-up period and gender ratio(P>0.05), and MIDLIF group was older in age(P<0.05). The operative time, leaving bed time, intraoperative blood loss, postoperative drainage volume, and average length of hospital stay were recorded. Visual analog scale(VAS) was used to assess low back and leg pain before operation, at postoperative 1, 3, 6 and 12 months, and final follow-up; and Oswestry disabity index(ODI) of lumbar spine was used to evaluate the overall quality of life of patients such as physical function and walking at postoperative 6 and 12 months, and final follow-up. The intervertebral canal cross-sectional area(ICCA) and dural sac cross-sectional area(DSCA) before operation and at final follow-up were compared between the two groups by lumbar 3D-CT. Anteroposterior and lateral lumbar X-ray images were taken before and at the last follow-up to compare the height of the intervertebral space(anterior, posterior and average heights), and complications were recorded. Results: All the patients successfully underwent the operation. 1 case of cerebrospinal fluid leakage occurred in the MIDLIF group and 1 case in MIS-TLIF group developed worsening contralateral neurological symptoms after operation, and both patients improved after symptomatic treatment. The mean follow-up time was 26.5 months(range, 22-28 months). At the last follow-up, 44 cases of bone graft were fused without loosening or fracture of internal fixation. There was no statistical significance between the two groups in postoperative leaving bed time or length of hospital stay(P>0.05). The operative time of MIDLIF group[(159.74±30.54)min] was significantly shorter than that of MIS-TLIF group[(202.46±61.56)min](P<0.05), and the postoperative drainage volume of MIS-TLIF group[(55.35±53.24)ml] was significantly less than that of MIDLIF group[(163.74±145.67)ml](P<0.05). There was no statistical difference in low back and leg pain VAS scores and ODI before operation between the two groups(P>0.05); and the VAS scores of low back pain and leg pain at 1, 3, 6 and 12 months postoperatively and final follow-up in both groups were significantly lower than those before operation, respectively(P<0.05), and no significant difference was found between groups at postoperative time points(P>0.05). At 6 and 12 months postoperatively and the final follow-up visit, the ODI of lumbar spine was lower than that before surgery of both groups(P<0.05), and there was no significant difference at postoperative time points between groups(P>0.05). There was no significant difference between the two groups in preoperative ICCA and DSCA(P>0.05); the ICCA and DSCA of the two groups were significantly increased after operation compared with those before operation, and the differences were statistically significant(P＜0.05). In addition, the ICCA in the MIDLIF group[(184.42±46.74)mm2] increased more significantly than that in the MIS-TLIF group [(135.54±42.63)mm2]. The anterior and average height of the postoperative intervertebral space in both groups were significantly greater than those before surgery(P<0.05), and there were no significant differences in anterior height and average height between the two groups (P>0.05)， while the posterior height of the postoperative intervertebral space was significantly different between groups(P<0.05). Conslusions: MIDLIF and MIS-TLIF unilateral approach bilateral decompression are both effective in the treatment of LSS patients with bilateral symptoms, and MIDLIF is relatively less in operative time and increases more in postoperative ICCA. MIDLIF is more extensive and direct in decompression.