Intrathecal morphine (ITM) is a well-known and extensively used method for analgesia in various surgical fields; however, its relevance in spine surgery is debated given the conflicting results in the literature. The aim of this study was to investigate the opioid-sparing effect of ITM after lumbar fusion.

This retrospective study involves two consecutive series of patients undergoing posterior lumbar fusion. The first cohort (control group, n=30) received the standard analgesia protocol while the second cohort (ITM Group, n=30) had the standard protocol supplemented with ITM (100μg of morphine hydrochloride). Morphine consumption, pain assessment (VAS), specific complications and postoperative recovery data were collected.

Consumption of morphine at 24hours and 48hours postoperatively was lower in the ITM group than the control group (p<0.001 and p=0.004). The pattern was similar for pain on VAS at H6, H24 and H36 (p=0.001; p=0.003 and p=0.01). The patients in the ITM group were able to get out of bed faster than the controls (1.13 days vs 1.83 days, p=0.002) and the discharge was earlier in the ITM group (5.1 days vs. 6.2 days, p=0.002). There was no difference in morphine-specific complications between the two groups.

Adding ITM to the analgesia protocol for lumbar fusion provides better management of postoperative pain, without increasing early complications, and it accelerates the recovery process after surgery.

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