To examine the relationship between obesity (BMI> 30) and the incidence of peri-operative complications, outcome of surgery and return to work in patients undergoing elective less invasive posterior lumbar inter-body fusion of the lumbar spine for low back pain and leg pain (“LI-PLIF”).

15 patients with BMI> 30 who underwent (“LI-PLIF”) were identified by reviewing the clinical notes and the pre-operative admission sheet from April 2005- to March 2007. All had suffered chronic low back pain for a minimum of 2 years that had proven unresponsive to conservative treatment. All patients underwent pre- and postoperative evaluations for Oswestry Disability Index (ODI), short-form 36 (SF-36), and visual analogue scores (VAS). Minimum follow-up was for 12 months.

Blood loss was dependent on BMI, number of levels, and surgical time. Post operative complication was more in the morbidly obese group than the in the obese. 10 patients (66.6%) returned to their normal pre-operative employment within the 12 months of the index procedure. There was a significant improvement in the ODI and in the VAS for back pain. Length of hospital stay was a mean of 3.3 days

Although surgery is technically more demanding our experience with less invasive posterior inter-body fusion has shown less incidence of post operative complication, less intra-operative blood loss and short in-patient hospital stay.

We conclude that a high BMI should not be a contraindication to surgery in patients with degenerative low back pain.

Ethics approval: None: Audit Interest Statement None