Background:

Discectomy is sometimes associated with recurrence of disc herniation and pain after surgery. The evidence to use an interspinous dynamic stabilization system or instrumented fusion in association with disc excision to prevent pain and re-operation remains controversial. In this study, we analyzed if adding interspinous spacer or fusion, offers advantages in relation to microdiscetomy alone.

Methods:

Patients with lumbar disc herniation were divided in 3 groups; microdiscectomy alone (MD), microdiscectomy plus interspinous spacer (IS) and open discectomy plus posterior lumbar interbody fusion (PLIF). The clinical efficacy was measured using the Owestry Disability Index (ODI). Other outcome parameters including visual analogue scale for pain (VAS) back and legs, length of stay, direct in-hospital cost, 90-day complication rate, and 1-year re-operation rate were also evaluated.

Results:

A total of 103 patients whose mean age was 39.1 (±8.5) years were included. A significant improvement of the ODI and VAS back and legs pain baseline score was detected in the 3 groups. After 1 year, no significant differences in ODI, VAS back and legs pain were found between the 3 groups. There was an increase of 169% of the total direct in- hospital cost in IS group and 287% in PLIF group, in relation to MD (p < 0.001). Length of stay was 86% higher in the IS group and 384% longer in the PLIF group compared to MD (p < 0.001). The 1 year re-operation rates were 5.6%, 10% and 16.2% (p = 0.33). Discectomy seems to be the main responsible for the clinical improvement, without the interspinous spacer or fusion adding any benefit. The addition of interspinous spacer or fusion increased direct in-hospital cost, length of stay, and did not protect against re-operation.