Technical Description of Oblique Lateral Interbody Fusion at L1-L5 (OLIF25) and at L5-S1 (OLIF51) and Evaluation of Complication and Fusion Rates

Background Context: The oblique lateral interbody fusion (OLIF) procedure is aimed at mitigating some of the challenges seen with traditional anterior lumbar interbody fusion (ALIF) and transpsoas lateral lumbar interbody fusion (LLIF), and allows for interbody fusion at L1-S1.

Purpose: The study aimed to describe the OLIF technique and assess the complication and fusion rates.

Study Design: This is a retrospective cohort study.

Patient Sample: The sample is composed of 137 patients who underwent OLIF procedure.

Outcome Measures: The outcome measures were adverse events within 6 months of surgery: infection, symptomatic pseudarthrosis, hardware failure, vascular injury, perioperative blood transfusion, ureteral injury, bowel injury, renal injury, prolonged postoperative ileus (more than 3 days), incisional hernia, pseudohernia, reoperation, neurologic deficits (weakness, numbness, paresthesia), hip flexion pain, retrograde ejaculation, sympathectomy affecting lower extremities, deep vein thrombosis, pulmonary embolism, myocardial infarction, pneumonia, and cerebrovascular accident. The outcome measures also include fusion and subsidence rates based on computed tomography (CT) done at 6 months postoperatively.

Methods: Retrospective chart review of 150 consecutive patients was performed to examine the complications associated with OLIF at L1-L5 (OLIF25), OLIF at L5-S1 (OLIF51), and OLIF at L1-L5 combined with OLIF at L5-S1 (OLIF25+OLIF51). Only patients who had at least 6 months of postoperative follow-up, including CT scan at 6 months after surgery, were included. Independent radiology review of CT data was performed to assess fusion and subsidence rates at 6 months.

Results: A total of 137 patients underwent fusion at 340 levels. An overall complication rate of 11.7% was seen. The most common complications were subsidence (4.4%), postoperative ileus (2.9%), and vascular injury (2.9%). Ileus and vascular injuries were only seen in cases including OLIF51. No patient suffered neurologic injury. No cases of ureteral injury, sympathectomy affecting the lower extremities, or visceral injury were seen. Successful fusion was seen at 97.9% of surgical levels.

Conclusions: Oblique lateral interbody fusion is a safe procedure at L1-L5 as well as L5-S1. The complication profile appears acceptable when compared with LLIF and ALIF. The oblique trajectory mitigates psoas muscle and lumbosacral plexus-related complications seen with the lateral transpsoas approach. Furthermore, there is a high fusion rate based on CT data at 6 months.