Length of stay, costs, and complications in lumbar disc herniation surgery by standard PLIF versus a new dynamic interspinous stabilization technique

BACKGROUND: The number of lumbar spine surgeries has been increasing during the last 20 years, which also leads to an increase in hospital costs and complications related to surgery. Therefore, there is a greater concern about the costs and safety of the techniques and implants used. METHODS: Patients (aged from 18 to 50 years) presenting with lumbago /sciatica (ICD-10-CM M54.3, M54.4) due to lumbar disc herniation lasting more than 12 weeks, were included. Patients with disc herniation larger than size-2 or size-3 according to the MSU Classification were eligible for participation. Intervention was divided in two groups. In Group 1, patients underwent microdiscectomy and Interspinous Dynamic Stabilization System (IDSS). Meanwhile, in Group 2, patients received discectomy and posterior lumbar interbody fusion (PLIF). The primary outcome measure was the length of stay and costs during hospital admission. We also evaluated several other outcome parameters, including 90- day readmission rate, 90-day complication rate, and re-operations rate. The study was an observational prospective cohort study carried out from January 2015 to August 2016 in which two surgical techniques were compared. Our hypothesis was that a less aggressive procedure, such as discectomy and DSS, will decrease the length of stay and costs, and that it will also reduce the rate of complications with respect to PLIF. RESULTS: A total of 67 patients (mean age 39.8 ± 8.4 years) were included. Patients in the PLIF group had a length of stay increase of 109% (4.52 ± 1.76 days vs 2.16 ± 1.18 days p < 0.001) and an in-hospital cost increase of 71% (1821.97 ± 460.41€ vs. 1066.20 ± 284.34€ p < 0.001). The reduction of one day of stay is equivalent to a reduction of total in-hospital costs of 12.5%. Patients in the IDSS cohort had no significant differences regarding PLIF cohort in the 90-day readmission rate (12.9% vs 11.1% € p > 0.999, respectively), 90-day re-operation rate (12.9% vs 11.1% € p > 0.999) and 90-day complication rates (35.5% vs 52.8% € p > 0.156). Dural tear and urinary tract infection rates were higher in the PLIF cohort (13.9% vs 3.2%. p = 0.205 and 11.1% vs 0% p = 0.118, respectively). Implant related complications were the most frequent in both IDSS and PLIF groups (32.3% vs 38.9% p = 0.572). CONCLUSIONS: Patients who underwent IDSS had a significant decrease of the length of stay and costs in relation to PLIF group. No significant differences were found in 90-day readmission and reintervention rates for both groups. Although differences were not significant, dural tear and urinary tract infection rates were lower in the interspinous group. IDSS or PLIF after discectomy, did not protect against subsequent 90-day re-operation or readmission compared to discectomy alone.