Lateral single position surgery offers similar outcomes to circumferential anterior-posterior fusion, new research suggests

Aaron J. Buckland

Lateral single position surgery (LSPS) and circumferential fusions have similar outcomes at two-years postoperatively, while reducing perioperative complications, improving perioperative efficiency and safety, a new study has shown. The multicentre retrospective cohort review, which was published in The Spine Journal by Aaron J. Buckland (Melbourne Orthopaedic Group, Melbourne, Australia) et al, sought to evaluate the safety and efficacy of LSPS versus gold-standard circumferential anterior-posterior fusion (FLIP).

The advantages of LSPS in the perioperative period was previously published by the authors in The Spine Journal.1 This study was an expansion of the original series of patients, with the aim to evaluate the clinical and radiographic results at minimum two-year follow-up.

A total of 442 patients undergoing 1-4 level lumbar fusion via LSPS or FLIP at three institutions were included in the study. Key outcome measures included levels fused, operative time, estimated blood loss (EBL), length of stay, perioperative complications, and reasons for reoperation at 30-days, 90-days, one-year, and two-years. Radiographic outcomes included lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), PI-LL mismatch, and segmental lumbar lordosis.

Patients were grouped as LSPS if anterior and posterior portions of the procedure were performed in the lateral decubitus position, and FLIP if patients were repositioned from supine or lateral to prone position for the posterior portion of the procedure under the same anaesthetic.

Groups were compared in terms of demographics, intraoperative, perioperative and radiological outcomes, complications and reoperations up to two-year follow-up. Measures were compared using independent samples or paired t-tests and chi-squared analyses with significance set at p<0.05.

Of the 442 patients who met the inclusion criteria, there were 352 in the LSPS group and 90 in the FLIP group. Significant differences were noted in age (62.4 vs. 56.9; p=<0.001) and smoking status (7% vs. 16%; p=0.023) between the LSPS and FLIP groups.

LSPS demonstrated significantly lower operative time (97.7 minutes vs. 297 minutes; p<0.001), fluoro dose (36.5mGy vs. 78.8mGy; p<0.001), EBL (88.8ml vs. 270ml; p<0.001), and length of stay (1.91 days vs. 3.61 days; p<0.001) compared to FLIP.

LSPS also demonstrated a 36% reduction in postoperative complications compared to FLIP (p=0.013), specifically regarding rates of ileus (0% vs. 5.6%; p<0.001). No differences in reoperation rates were noted at 30-days (1.7% [LSPS] vs. 4.4% [FLIP]; p=0.125), 90-days (5.1% vs. 5.6%; p=0.795) or at two-year follow-up (9.7% vs. 12.2%; p=0.441).

LSPS and FLIP patients had similar lumbar lordosis, segmental lordosis and PI-LL mismatch. There were no significant differences in rates of fusion (94.3% [LSPS] vs. 97.8% [FLIP]; p=0.266) or subsidence (6.9% vs. 12.2%; p=0.260).

Speaking to Spinal News International, Buckland said: “This novel technique is performed (often simultaneously) in a lateral decubitus position for both anterior and posterior portions of the procedure, where previously ALIF would be performed supine (or LLIF in lateral decubitus) and posterior instrumentation performed prone. We have now demonstrated not only improved operative efficiency, perioperative safety and reduction in length of stay; and now the clinical efficacy of LSPS, which is as good as the gold standard anterior-posterior fusion. LSPS provides all of the benefits of minimally invasive surgery, while still maintaining the efficacy of anterior and posterior column fusion in terms of alignment and fusion rates.

“These multicentre results demonstrate that there was no increased risk in posterior instrumentation, or increased risk of vascular injury in a lateral decubitus position—two factors which often deter early adopters.

“With the current economic pressure to demonstrates value-based care, LSPS allows better utilisation of healthcare resources by a large reduction in operating room time, shorter length of stay, a reduction in complications and low reoperation rates. We (the authors) believe these results demonstrate that LSPS is the new gold-standard in lumbar fusion in degenerative conditions.”



1. Buckland AJ, Ashayeri K, Leon C, Manning J, Eisen L, Medley M, Protopsaltis TS, Thomas JA. Single position circumferential fusion improves operative efficiency, reduces complications and length of stay compared with traditional circumferential fusion. Spine J. 2021 May;21(5):810-820.


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