Lateral fusion after oblique lateral lumbar interbody fusion: incidence, imaging characteristics, and contributing factors
10.3760/cma.j.cn121113-20241108-00635
- VernacularTitle:斜外侧腰椎椎间融合术后侧方融合的发生率及其相关因素分析
- Author:
Yongjun TONG
1
;
Chudi FU
;
Junhui LIU
;
Bao HUANG
;
Yilei CHEN
;
Zhi SHAN
;
Xuyang ZHANG
;
Shunwu FAN
;
Fengdong ZHAO
Author Information
1. 浙江大学医学院附属邵逸夫医院骨科，杭州 310016
- Publication Type:Journal Article
- Keywords:
Lumbar vertebrae;
Intervertebral disc degeneration;
Spinal fusion;
Lateral fusion;
Central fusion
- From:
Chinese Journal of Orthopaedics
2025;45(7):420-428
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To evaluate the characteristic manifestations of lumbar fusion following oblique lateral interbody fusion (OLIF), determine the specific incidence of these patterns, and the identify factors associated with fusion characteristics.Methods:This retrospective study analyzed 209 patients who underwent OLIF surgery at Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, between July 2017 and September 2023. The cohort had a mean age of 64.2±9.8 years and included 125 males and 84 females. A total of 338 lumbar segments were assessed, comprising 159 segments treated with stand-alone OLIF (OLIF-SA) and 179 segments treated with OLIF combined with posterior pedicle screw fixation (OLIF-PSF). Inclusion criteria were: patients aged 18-80 years who underwent OLIF with complete radiographic records. Surgical parameters, including fixation method, number of fused segments, surgical approach, and cage dimensions (height and width), were obtained from operative records. Radiographic evaluation included preoperative osteophytes, Hounsfield unit (HU) values of endplates, and cage positioning. Fusion rate, fusion pattern (lateral vs. central), cage subsidence, and related influencing factors were assessed. Clinical outcomes were measured via the Oswestry disability index (ODI) and visual analog scale (VAS) preoperatively, immediately postoperatively, and at 1-year follow-up. Results:The overall fusion rate was 98.2% (332/338), with a non-union rate of 1.8% (6/338). The incidence of lateral fusion was 40.2% (136/338). In the OLIF-SA group, lateral and central fusion rates were 50.3% (80/159) and 49.7% (79/159), respectively, with no cases of non-union. In the OLIF-PSF group, lateral fusion occurred in 31.3% (56/179), central fusion in 65.4% (117/179), and non-union in 3.3% (6/179), with statistically significant differences between groups ( P<0.05). Preoperative osteophytes and higher endplate HU values were significantly associated with lateral fusion ( P<0.05). However, cage dimensions and cage position (anterior-posterior and lateral placement) were not significantly associated with fusion pattern ( P>0.05). Overall, 61.5% (208/338) of segments showed no cage subsidence; 24.5% (83/338) had settling, and 14.0% (47/338) had grade 1 or higher subsidence. Among lateral fusion cases, the rates of no subsidence, anchoring, grade 1, grade 2, and grade 3 subsidence were 67.6%, 21.3%, 7.4%, 3.9%, and 0.7%, respectively. In the central fusion group, these rates were 59.2%, 27.6%, 9.2%, 2.5%, and 1.3%, respectively. In the non-union group, grade 2 and 3 subsidence occurred in 50% (3/6) each, significantly higher than in the other fusion groups ( P<0.05). Post hoc analysis confirmed that grade 2 and 3 subsidence rates were significantly elevated in the non-union group compared to the lateral and central fusion groups, while other subsidence categories showed no significant differences across groups. Clinically, patients showed significant improvements in ODI and VAS scores following surgery ( P<0.05). Conclusions:Lateral fusion occurred in 40.2% of OLIF cases. The OLIF-SA technique, preoperative osteophytes, and elevated preoperative HU values were significantly associated with lateral fusion. In contrast, surgical approach, number of fused segments, cage height, width, and cage positioning did not significantly influence the occurrence of lateral fusion.
