Lateral Lumbar Interbody Fusion at L4-5 Has a Low Rate of Neurological, Psoas-Related and Abdominal Complications in Appropriately Selected Patients When Utilising a Standardised Surgical Technique

Introduction: Lateral lumbar interbody fusion (LLIF) is a minimally-invasive technique that allows for powerful disc and foraminal height restoration, correction of lordosis and high rates of fusion. Despite these benefits there is still concern among some surgeons regarding the safety of the technique for fusion at L4/5. This study aims to reassess the rate of neurological, psoas-related and abdominal complications associated with L4-5 LLIF with standardised preoperative assessment and procedural technique.

Methods: A multi-center retrospective cohort review of consecutively enrolled patients that underwent LLIF including the L4-5 disc level by 7 surgeons at 7 institutions in 3 countries over a 5-year period was performed. Patient demographics, procedural characteristics, reoperations and complications, including femoral and non-femoral neurapraxia, thigh pain, hip flexor weakness and abdominal complications were analysed. Neurological and psoas-related complications were attributed to LLIF or posterior instrumentation and presence of persistent symptoms determined at 1-year postoperatively.

Results: In total, 517 patients were included with a mean age of 65.0  10.3 years and BMI of 29.2  5.5 kg/m2. A mean 1.2  0.6 levels were fused with LLIF and 1.6  0.9 posterior levels were fused. Femoral neurapraxia occurred in 1.2% of patients, of which 0.8% were LLIF-related and 0.4% persistent at 1-year postoperatively. Non-femoral neurapraxia occurred in 1.8% of patients, 0.2% were LLIF-related and 1.0% persistent at 1-year. All LLIF-related neurapraxias resolved by 1-year. Thigh pain was experienced in 6.2% of patients, 6.0% were LLIF-related and 0.6% were persistent at 1-year. Hip flexor weakness occurred in 2.7% of patients, 1.6% were LLIF-related and 0.6% were persistent at 1-year. No patients experienced bowel injury, 0.6% experienced intraoperative vascular injury (not LLIF-related) and 1.0% experienced ileus. Reoperations occurred in 1.0% of patients within 30-days, 7.2% within 90-days and 7.9% within 1-year postoperatively.

Conclusion : LLIF involving the L4-5 disc level has a low rate of persistent neurological, psoas-related and abdominal complications in appropriately indicated patients and maintaining standardised surgical technique.