Midterm outcomes of oblique lumbar interbody fusion with anterolateral screw fixation versus transforaminal lumbar interbody fusion for adjacent segment disease: a retrospective comparative study

Retrospective comparative study. Oblique lumbar interbody fusion combined with anterolateral screw fixation (OLIF-AF) and transforaminal lumbar interbody fusion (TLIF) have increasingly been applied in the treatment of adjacent segment disease (ASD) following prior lumbar fusion. However, the optimal surgical strategy for ASD remains controversial. This study compared the interim clinical efficacy and radiographic outcomes of oblique lumbar interbody fusion combined with anterolateral screw fixation (OLIF-AF) with transforaminal lumbar interbody fusion (TLIF) for the treatment of adjacent segment disease (ASD) after lumbar fusion. This retrospective study included patients with ASD who underwent revision lumbar fusion surgery at our institution between January 2017 and January 2023. A total of 54 patients were included according to the inclusion and exclusion criteria. Among these patients, 32 underwent oblique lumbar interbody fusion combined with anterolateral single screw fixation (OLIF-AF group), and 22 underwent transforaminal lumbar fusion (TLIF group). The perioperative outcomes, clinical outcomes (visual analog scale (VAS) and Oswestry Disability Index (ODI) for back and leg pain assessed preoperatively, at 3 months, 6 months, 12 months and at the final follow-up), radiological parameters (intervertebral disc height (IDH), intervertebral foramen height (IFH) and lumbar lordosis (LL)), intervertebral fusion status and complications were compared between the two groups of patients. There were no statistically significant differences in baseline characteristics (age, sex, body mass index, follow-up duration, and time to operative ASD) between the two groups (all P > 0.05). During the perioperative period, the OLIF-AF group presented significantly better results than the TLIF group in terms of the mean operation time per level (86.25±22.17 min), total hospital stay (6.30±1.12 d), postoperative hospital stay (2.42±0.90 d), and postoperative hemoglobin loss (11.56±5.75 g/L), which were 180.61±42.51 min, 12.10±6.08 d, 7.88±4.70 d, and 21.47±11.01 g/L, respectively (all P < 0.05). In terms of clinical efficacy, both groups showed significant improvements in VAS scores for low back pain, leg pain, and the ODI index at 3 months post-operatively and at the final follow-up compared with the preoperative values, indicating comparable long-term efficacy between the groups. In terms of imaging, the IDH (11.51±1.88 mm, 10.26±1.20 mm) and IFM (19.67±1.72 mm, 17.97±1.98 mm) in the OLIF-AF group were significantly greater than those in the TLIF group at the same time point ( P <0.05). Both groups showed significant improvement in LL compared with the preoperative values on both postoperative day 1 and at the final follow-up ( P <0.05). The improvement in the OLIF-AF group (48.02±8.08° on postoperative day 1 and 46.96±9.14° at the final follow-up) was greater than that in the TLIF group (44.53±3.14° on postoperative day 1 and 43.71±3.12° at the final follow-up), but the difference was not statistically significant ( P =0.06, 0.08). There was no significant difference in the overall complication rate between the OLIF-AF and TLIF groups (21.87% vs. 27.27%, P = 0.64). The incidence of cage subsidence was 15.62% and 9.09%, respectively ( P = 0.48). At the 12-month follow-up, successful radiographic fusion (Bridwell Grade I or II) was achieved in all patients in both groups (100%). Both OLIF-AF and TLIF provide satisfactory midterm clinical and radiological outcomes for ASD patients after lumbar fusion. OLIF-AF may offer advantages in terms of reduced surgical invasiveness, faster postoperative recovery, and greater restoration of disc and foraminal height in selected patients with ASD.