Oblique lumbar interbody fusion combined with stress end plate augmentation and anterolateral screw fixation for degenerative lumbar spinal stenosis with osteoporosis: a matched-pair case-controlled study

BACKGROUND CONTEXT

Oblique lumbar interbody fusion (OLIF) has been proven to be effective in treating degenerative lumbar spinal stenosis (DLSS). Whether OLIF is suitable for treating patients with DLSS with osteoporosis (OP) is still controversial. Bone cement augmentation is widely used to enhance the internal fixation strength of osteoporotic spines. However, the effectiveness of OLIF combined with bone cement stress end plate augmentation (SEA) and anterolateral screw fixation (AF) for DLSS with OP have not confirmed yet.

PURPOSE

To evaluate the clinical, radiological, and functional outcomes of OLIF-AF versus OLIF-AF-SEA in the treatment of DLSS with OP.

STUDY DESIGN

Retrospective case-control study.

PATIENT SAMPLE

A total of 60 patients with OP managed for DLSS at L4-L5.

OUTCOME MEASURES

Visual analog scale (VAS) score of the lower back and leg, Oswestry Disability Index (ODI), disk height (DH), lumbar lordosis (LL), segmental lordosis (SL), cage subsidence and fusion rate.

METHODS

The study was performed as a retrospective matched-pair case‒controlled study. Patients with OP managed for DLSS at L4-L5 between October 2017 and June 2020 and completed at least 2 years of follow-up were included, which were 30 patients treated by OLIF-AF and 30 patients undergoing OLIF-AF-SEA. The demographics and radiographic data, fusion status and functional outcomes were therefore compared to evaluate the efficacy of the two approaches.

RESULTS

Pain and disability improved similarly in both groups at the 24-month follow-up. However, the SEA group had lower pain and functional disability at 3 months postoperatively (p<.05). The mean postoperative disc height decrease (△DH) was significantly lower in the SEA group than in the control group (1.17±0.81 mm vs 2.89±2.03 mm; p<.001). There was no significant difference in lumbar lordosis (LL) or segmental lordosis (SL) between the groups preoperatively and 1 day postoperatively. However, a statistically significant difference was observed in SL and LL between the groups at 24 months postoperatively (p<.05). CS was observed in 4 cases (13.33%) in the SEA group and 17 cases (56.67%) in the control group (p<.001). A nonsignificant difference was observed in the fusion rate between the SEA and control groups (p=.347) at 24 months postoperatively.

CONCLUSIONS

This study revealed that OLIF-AF-SEA was safe and effective in the treatment of DLSS with OP. Compared with OLIF-AF, OLIF-AF-SEA results in a minor postoperative disc height decrease, a lower rate of CS, better sagittal balance, and no adverse effect on interbody fusion.

Biomechanical Evaluation and Preliminary Clinical Results of Anterolateral Screw Fixation for Oblique Lumbar Interbody Fusion Surgery

BACKGROUND

The most common complication of oblique lumbar interbody fusion (OLIF) is endplate fracture/subsidence. The aim of this study was to evaluate biomechanical stability in patients undergoing OLIF surgery with anterolateral screw fixation (ASF).

METHODS

Based on a previously validated model technique, L4-L5 functional surgical models corresponding to the ASF and bilateral pedicle screw fixation (BPSF) methods were created. Finite element models were developed to compare the biomechanics of the ASF and BPSF groups. We retrospectively analyzed 18 patients with lumbar degenerative diseases who underwent OLIF with ASF in Shenzhen Hospital of Southern Medical University from April 2020 to April 2021. Intraoperative and postoperative complications were observed.

RESULTS

Compared with the BPSF model, the maximum stresses of the L4 inferior endplate and L5 superior endplate were greatly increased in the ASF model. The contact surface between the vertebrae and screw (CSVS) in the ASF model produced nearly 100% more stress than the BPSF model at all moments. In clinical practice, after a 12-month follow-up, 7 adverse events were observed, including 3 cases of left thigh pain/numbness, 3 cases of cage subsidence, and 1 case of screw loosening.

CONCLUSIONS

OLIF surgery with ASF could not reduce the maximum stresses on the endplate and CSVS, which may be a potential risk factor for cage subsidence and screw loosening.

Minimally Invasive Oblique Lateral Lumbar Interbody Fusion Combined with Anterolateral Screw Fixation for Lumbar Degenerative Disc Disease

OBJECTIVE

The purposes of the present study were to introduce an indirect decompression using oblique lateral lumbar interbody fusion combined with anterolateral screw fixation (OLIF-AF) for the treatment of lumbar degenerative disc disease and examine the clinical efficacy and radiographic outcomes.

METHODS

A total of 65 patients had undergone single-level OLIF-AF at L2-L5 from December 2017 to August 2018. The cross-sectional area of the thecal sac was evaluated using magnetic resonance imaging. The disk height, foraminal height (FH), and degree of upper vertebral slippage were evaluated using computed tomography. The visual analog scale score and Oswestry disability index were recorded pre- and postoperatively.

RESULTS

The visual analog scale scores and Oswestry disability index had significantly improved after surgery (P < 0.001). At 3 days postoperatively, the cross-sectional area had improved from 93.2 ± 14.4 mm² to 124.2 ± 7.5 mm² (P < 0.001), the disk height had increased from 9.9 ± 1.7 mm to 12.7 ± 1.0 mm (P < 0.001), the left FH had increased from 16.6 ± 2.0 mm to 19.6 ± 2.0 mm (P < 0.001). In contrast, the right FH had increased from 16.7 ± 2.1 mm to 19.9 ± 2.0 mm (P < 0.001), and the degree of upper vertebral slippage had decreased from 14.2% ± 3.1% to 4.6% ± 2.8% (P < 0.001), respectively. At the 12-month follow-up examination, these parameters showed no statistically significant differences compared with the values at 3 days postoperatively (P > 0.05). Adverse events were observed in 15 patients (23.1%) patients and included pain at the iliac bone donor site in 1 (1.5%), left thigh pain/numbness in 2 (3.1%), quadriceps weakness in 2 (3.1%), psoas weakness in 3 (4.6%), intraoperative endplate injury in 2 (3.1%) and cage subsidence in 5 (7.7%).

CONCLUSIONS

Our results have shown that OLIF-AF surgery is a relatively safe and effective surgical option for LDDD at L2-L5. Cage subsidence was the most common operative complication.