A COMPARISON OF POSTOPERATIVE COMPLICATIONS OF THE WILTSE VERSUS MIDLINE APPROACH IN DEGENERATIVE CONDITIONS OF THE LUMBAR SPINE: A PILOT RANDOMIZED CONTROLLED TRIAL (RCT)

Post-operative infection after instrumented spinal fusion surgery is a devastating complication for patients. Short- and long-term clinical outcomes are affected but also patients consume valuable hospital resources and often require prolonged intravenous antibiotic treatment. The Wiltse/paramedian approach has been shown to decrease infection rates significantly in prior work compared to the traditional midline approach (1). There are few studies to prospectively evaluate post-operative infection as a primary outcome between the two approaches. The primary objective of this study was to compare the infection rates between the Wiltse and midline approaches to the lumbar spine. Secondarily, we sought to determine the feasibility of recruitment for a larger, multi-centre trial and compare other patient reported outcomes and re-operation rates for both procedures. A single-center, pilot RCT was conducted to compare patients undergoing native primary single or two level posterior interbody fusion surgery from 2017 to September 2023. Participants were randomly assigned to either the Wiltse or midline surgical incision study group (1:1). All patients returned to follow-up at two weeks, six weeks, three months, one year, and two years. All adverse events were recorded. Incidence of adverse events were statistically analyzed using STATA software. Seventy-five patients with degenerative conditions of the lumbar spine were included in the study. The average follow-up time was 1.9 years. Thirty-seven patients were randomly assigned to the Wiltse surgical incision group and 38 assigned to the midline incision group. The number of deep post-operative infections was higher in the midline group (5/38, 13.2%) versus the Wiltse group (2/37, 5.4%) but this was not statistically significant (p = 0.430). Rates of revision surgery were also higher in the midline group compared to the Wiltse group (p = 0.065). Ten of the 38 patients in the midline group underwent reoperation (four patients undergoing irrigation/debridement for deep infection, four returning for hardware failure, one for pseudarthrosis, and one for adjacent segment degeneration) (10/38, 26.3%). Three of 37 patients in the Wiltse group underwent re-operation (one for hematoma, one for irrigation/debridement, and one for screw revision) (3/37, 8.1%). The Wiltse group had a greater incidence of superficial wound infection (6/37, 16.2%) versus midline (1/38, 2.6%) (p = 0.056). The overall number of adverse events for each group were similar (16 midline versus 13 Wiltse). Patients who underwent the Wiltse approach had a non-statistically significant difference in deep and superficial wound infection rates, and a decreased risk of requiring revision surgery. There were no differences in the number of post-operative complications or adverse events between the two groups. These results highlight the potential value of a multi-centre RCT comparing the deep infection rate and number of adverse events of the Wiltse versus midline approaches for single and two level posterior interbody fusions of the lumbar spine.