Subsidence of Interbody Cage Following Oblique Lateral Interbody Fusion: An Analysis and Potential Risk Factors

Study Design Retrospective cohort study Objectives This study aimed to report the incidence and potential risk factors of polyetheretherketone (PEEK) cage subsidence following oblique lateral interbody fusion (OLIF) for lumbar degenerative diseases. We proposed also an algorithm to minimize subsidence following OLIF surgery. Methods The study included a retrospective cohort of 107 consecutive patients (48 men and 59 women; mean age, 67.4 years) who had received either single- or multi-level OLIF between 2012 and 2019. Patients were classified into subsidence and non-subsidence groups. PEEK cage subsidence was defined as any violation of either endplate from the computed tomography scan in both sagittal and coronal views. Preoperative variables such as age, sex, body mass index, bone mineral density (BMD) measured by preoperative dual-energy X-ray absorptiometry, smoking status, corticosteroid use, diagnosis, operative level, multifidus muscle cross-sectional area, and multifidus muscle fatty degeneration were collected. Age-related variables (height and length) were also documented. Univariate and multivariate logistic regression analyses were used to analyze the risk factors of subsidence. Results Of the 107 patients (137 levels), 50 (46.7%) met the subsidence criteria. Higher PEEK cage height had the strongest association with subsidence (OR = 9.59, P < .001). Other factors significantly associated with cage subsistence included age >60 years (OR = 3.15, P = .018), BMD <−2.5 (OR = 2.78, P = .006), and severe multifidus muscle fatty degeneration (OR = 1.97, P = .023). Conclusions Risk factors for subsidence in OLIF were age >60 years, BMD < −2.5, higher cage height, and severe multifidus muscle fatty degeneration. Patients who had subsidence had worse early (3 months) postoperative back and leg pain.

The Role of Hounsfield Unit in Intraoperative Endplate Violation and Delayed Cage Subsidence with Oblique Lateral Interbody Fusion

Study Design Retrospective clinical case series. Objectives To investigate the risk factors for intraoperative endplate violations and delayed cage subsidence after oblique lateral interbody fusion (OLIF) surgery. Secondly, to examine whether low Hounsfield unit (HU) values at different regions of the endplate are associated with intraoperative endplate violation or delayed cage subsidence. Methods 61 patients (aged 65.1 ± 9.5 years; 107 segments) who underwent OLIF with or without posterior instrumentation from May 2015 to April 2019 were retrospectively studied. Intraoperative endplate violation was measured on sagittal reconstructed computerized tomography (CT) images immediate postoperatively, while delayed cage subsidence was evaluated using lateral radiographs and defined at 1-month follow-up or later. Demographic information and clinical parameters such as age, body mass index, bone mineral density, number of surgical levels, cage dimension, disc height restoration, visual analogue scale (VAS), and HU at different regions of the endplate were obtained. Results Total postoperative cage subsidence was identified in 45 surgical levels (42.0%) in 26 patients (42.6%) up till postoperative 1-year follow-up. Low HU value at the ipsilateral epiphyseal ring was an independent risk factor for intraoperative endplate violation ( P = .008) with a cut-off value of 326.21 HUs. Low HU values at the central endplate had a significant correlation with delayed cage subsidence in stand-alone cases ( P = .013) with a cut-off value of 296.42 HUs. VAS scores were not different at 1 week postoperatively in cases with or without intraoperative endplate violation (3.12 ± .73 vs 2.89 ± .72, P = .166) and showed no difference at 1 year with or without delayed cage subsidence (1.95 ± .60 vs 2.26 ± .85, P = .173). Conclusions Intraoperative endplate violation and delayed cage subsidence are not uncommon with OLIF surgery. HUs of the endplate are good predictors for intraoperative endplate violation and cage subsidence since they can represent the regional bone quality of the endplate in contact with the implant. VAS improvements were not affected by intraoperative endplate violation or delayed cage subsidence at 1-year follow-up. Level of Evidence Level III.

Oblique Lateral Interbody Fusion Combined with Lateral Plate VS. Combined with Posterior Pedicle Screw Fixation in Lumbar Degenerative Diseases

Background The oblique lateral interbody fusion (OLIF) is a minimally invasive indirect decompression technique for the treatment of degenerative spinal disease. OLIF with posterior pedicle screws fixation frequently is performed, whereas it requires much more surgery time and blood loss. The purpose of this study was to compare the oblique lateral interbody fusion (OLIF) combined with lateral plate (LP) vs. OLIF combined with posterior pedicle screw (PS) fixation for the treatment of lumbar degenerative diseases.Methods The clinical data of 53 patients with lumbar degenerative diseases who underwent OLIF from January 2020 to September 2020 were retrospectively analyzed，24 in OLIF combined with lateral plate (OLIF+LP) group and 29 in OLIF combined with pedicle screw (OLIF+PS) group. All patients completed a minimum 1-year follow-up. The duration of operation, blood loss, fusion rate and complications were recorded. The visual analog scale (VAS) score, Oswestry Disability Index (ODI), disc height (DH), foraminal height (FH) and cross-sectional area (CSA) were also evaluated.Results The operation time was 75.41±11.53 min in the OLIF+LP group, which shorter than that in OLIF+PS group(127.05±5.62min, P<0.01). Also, the blood loss was significantly less in the OLIF+LP group (39.55±5.32 ml ) than in the OLIF+PS group (89.81±9.62, P<0.01). The VAS and ODI scores both significantly reduced after operation in OLIF+LP group. There was no difference either in VAS or ODI scores by 1 year after surgery between two groups (P>0.01). The DH, FH, and CSA parameters were all improved significantly after operation in both groups, however, there was no significant difference at the any follow-up point between the two groups. The total complication rate was 13.21% (7/53) in this study, and there was no siginificant difference between the two groups. The fusion rate was 91.67% in the OLIF+LP group and 93.10% in the OLIF+PS group (P =0.69).Conclusions OLIF+LP fixation seems to be a valuable surgical option for single-segmental lumbar degenerative disease, it can achieve much better clinical outcomes than OLIF+PS group.

Curative Effect of Oblique Lateral Interbody Fusion in the Treatment of Lumbar Tuberculosis

Objective: This research aimed to investigate the curative effect of oblique lateral interbody fusion (OLIF) in the treatment of lumbar tuberculosis. Methods: A total of 32 patients, including 18 males and 14 females (29-58 years old, with the mean age of 47) who were admitted to our hospital from October 2016 to June 2020 and treated with oblique lateral interbody fusion combined with vertebral screw internal fixation, were retrospectively collected. The segmental distribution of lesions was L2- L316 cases, L3-L411 cases and L4-L55 cases. At first, preoperative antituberculous drug treatment was standardized for 2-4 weeks. Furthermore, intraoperative blood loss, operation time, postoperative complications, ESR, CRP, VAS, JOA and ASIA scores were recorded before and after surgery and at the last follow-up. In addition, antituberculous drug therapy was regulated continuously after surgery.Results: All patients were followed up for 12-17 months, with an average of 14 months. ① The average operation time was (132.5±21.4) min, and the intraoperative blood loss was (227.3±43.1) ml. ② Preoperative ESR was (74.56±15.43) mmol/h, and CRP was (43.21±19.37) mg/L. Seven days after surgery, ESR was (42.37±19.26) mmol/h, and CRP was (22.51±18.42) mg/L. In the last follow-up, ESR was (9.25±4.13) mmol/h, and CRP was (8.17±3.21) mg/L. They have statistically significant differences before surgery, seven days after the surgery and in the last follow-up (P<0.05). ③ The average VAS score before surgery was (7.21±1.40) points, the average JOA score was (18.24±4.13) points, the average VAS score seven days after surgery was (2.23±1.32) points, the average JOA score was (24.72±3.19) points, and the average VAS score in the last follow-up was (1.63±0.54) points. JOA score was (27.72±2.61). They have statistically significant differences before surgery, seven days after the surgery and in the last follow-up (P<0.05) ④Six patients had neurologic symptoms with ASIA grade D before surgery, 2 patients recovered to Grade E seven days after surgery, and the remaining 4 patients also recovered to grade E in the last follow-up. Besides, 26 patients were graded as Grade E before surgery, seven days after surgery and in the last follow-up. ⑤ After surgery, 1 patient suffered psoas major muscle damage, which was manifested as reduced hip flexion strength of the lower extremity, and returned to normal three weeks later. Apart from that, none of the patients had complications such as abdominal organ injury and poor wound healing. Conclusion: OLIF is a new minimally invasive method for treating lumbar tuberculosis, with short operation time, less blood loss, convenient operation, thorough removal of lesions, and good long-term follow-up effect. It is worthy of promotion and application.

Comparison of clinical outcomes achieved with oblique lateral interbody fusion with or without supplementary instrumentation in patients with single-level lumbar degenerative disease

Background Oblique lateral interbody fusion (OLIF) is applied often to treat degenerative disc disease in the lumbar spine. Stand-alone OLIF prevents morbidities associated with supplemental fixation and is less expensive. However, it remains controversial whether stand-alone OLIF is sufficient to avoid subsidence for single-level diseases. Additionally, bilateral pedicle screw (BPS) and bilateral transfacet screw (BTS) fixation are well-established posterior fixation methods that can offer improved biomechanical stability. But the comparison of clinical outcomes of OLIF with and without supplementary instrumentation is lack. Methods We retrospectively examined 20 patients who underwent single-level stand-alone OLIF for symptomatic lumbar degenerative disease at L1–L5 (SA group). Groups of patients treated with OLIF plus BPS (n = 20, BPS group) or BTS (n = 20, BTS group) were matched for age, sex, diagnosis, operative level, body mass index, and bone mineral density. The disk height index (DHI), segmental lordotic (SL) angle, and lumbar lordotic (LL) angle were measured preoperatively and at 3 days and 6 months postoperatively. Clinical outcomes were evaluated. Results Significant disc height loss was observed in all groups, but was greater in the SA and BTS groups than in the BPS group at the 6-month follow-up. The SL and LL angles were not affected in any group. The operative time was significantly less in the SA group, and the estimated blood loss was significantly higher in the BPS group. At 6 months post-surgery, improvements in clinical outcomes were evident in all groups, but the VAS (back pain), JOA, and ODI scores were worse in the SA group than in the other groups. Conclusions Stand-alone OLIF was associated with greater subsidence and poorer clinical outcomes compared with OLIF plus supplementary instrumentation. The addition of BTS did not decrease the degree of subsidence, but provided clinical outcomes comparable to those achieved with BPS.

Oblique Lateral Interbody Fusion Combined With Lateral Plate Fixation for the Treatment of Lumbar Degenerative Diseases: a Preliminary Clinical Study

Background The oblique lateral interbody fusion (OLIF) is a minimally invasive indirect decompression technique for the treatment of lumar spine disease. The OLIF has usually combined with supplemental posterior pedicle screw fixation for decreasing the perioperative complications. The purpose of this study was to evaluate clinical efficacy and complications of oblique lateral interbody fusion (OLIF) combined with lateral plate instrumentation for the treatment of lumbar degenerative diseases.Methods From May 2020 to August 2020, the clinical data of 20 patients who underwent OLIF combined with lateral plate instrumentation were retrospectively analyzed. The operation time, blood loss, and the complications were recorded. Also, the radiological parameters, Visual Analog Scale (VAS) score and Oswestry Disability Index (ODI) were evaluated before and after surgery.Results The average operation time, blood loss, and length of hospital stay were 75.41±11.53 min, 39.57±9.22 ml, and 7.22±1.85 days, respectively. The VAS and ODI had both significantly improved after surgery (7.23±1.26 VS 2.15±0.87; 60.27±7.91 VS 21.80±6.32, P < 0.001). The postoperative disk height (DH) was 13.02±8.83 mm, which is much higher than before (P < 0.001); The postoperative foraminal height (FH) improved significantly (16.18±3.49 VS 21.54±2.12 mm, P < 0.01), and the cross-sectional area (CSA) had improved from 88.95±14.79 mm2 to 126.53±8.83 mm2 (P < 0.001). The radiological fusion rate was 95% at the last follow-up, while cage subsidence was found in one case. No major complications, such as ureteral injury, vascular injury and vertebral body fracture occurred.Conclusions OLIF combined with lateral plate fixation can avoid the lumbar posterior surgery, minimize the operation time, blood loss and the posterior ligament complex disruption. It can realize one-stage intervertebral fusion and instrumentation through a single small incision.