Early efficacy and learning curve study of Endo-LIF and UBE-LIF in the treatment of single-level lumbar degenerative diseases

English Keywords:Lumbar degenerative diseases  Endoscopic lumbar interbody fusion  Unilateral biportal endoscopic lumbar interbody fusion  Lumbar posterior decompression and fusion  Early efficacy  Learning curve

English Abstract:

  【Abstract】 Objectives: To compare the clinical efficacy of endoscopic lumbar interbody fusion(Endo-LIF) and unilateral biportal endoscopic lumbar interbody fusion(UBE-LIF) in the treatment of single-segment lumbar degenerative diseases(LDD) and analyze the learning curves of both techniques. Methods: Retrospective analysis was conducted on 54 single-segment LDD patients treated with UBE-LIF or Endo-LIF in the Orthopedics Department of Clinical College of Guizhou Medical University from October 2019 to March 2022. There were 26 males and 28 females, aged 65.0±4.5(55-71) years old, and the operative segments were L3/4 in 6 patients, L4/5 in 29 patients, and L5/S1 in 19 patients. The patients were divided into group A(Endo-LIF, n=24) and group B(UBE-LIF, n=30) according to the surgical method, and subdivided into group A1 of the first 12 cases and group A2 of the later 12 cases as well as group B1 of the first 15 cases and group B2 of the later 15 cases in accordance with chronological order. The operative time, postoperative hospital stay, and complications were recorded; Visual analogue scale(VAS) of low back and leg pain and Oswestry disability index(ODI) were collected before operation and at 3 months, 6 months and 1 year after operation; Modified Macnab scores and fusion conditions at final follow-up were observed, and excellent and good rate of modified Macnab criteria and fusion rate were calculated. The trends of changes in operative time with the number of patients of both Endo-LIF and UBE-LIF were analyzed by curve regression analysis. Results: The patients were followed up for 12-14months(12.5±0.7months). Compared with group A2, group A1 had a significantly longer operative time(P<0.001), but there was no significant difference in postoperative hospital stay(P>0.05). The operative time of group A was significantly less that those of groups B1 and B2(P<0.001), and that of group B1 was significantly more than that of group B2(P<0.001). The postoperative hospital stay in group A was less than that in group B1(P<0.001), and there was no significant difference between group B2 and group A or group B1(P>0.05). 1 case of dural tear in group A1 and 2 cases of dural tear occurred in group B1, and the symptoms were relieved after conservative managements; and 1 case of spinal cord hypertension in group B1, which was related to the long operative time and stimulation of saline irrigation, improved after bed rest. No related complications occurred in groups A2 and B2. The postoperative VAS scores of low back and leg pain and ODI were significantly improved when compared with preoperative ones in each group(P<0.001), and they decreased over time(P<0.001). According to the modified MacNab criteria, the excellent and good rate was 91.7%(22/24) in group A and 90.0%(27/30) in group B; The fusion rate was 87.5% in group A and 90.0% in group B. According to the curve regression analysis, the operative time of group A and group B reached relative stability after 12 and 15 cases, respectively. Conclusions: Endo-LIF and UBE-LIF are safe and effective in the treatment of LDD. The operative time of Endo-LIF and UBE-LIF decreased gradually with the increase of the number of cases. Endo-LIF and UBE-LIF are stable in operative time after 12 and 15 cases, respectively.