# Dexamethasone as an additive to bupivacaine in an ultrasound-guided adductor canal block for the management of persistent pain after arthroscopic reconstruction of the anterior cruciate ligament: a randomized, double-blind study

## TL;DR

Adding dexamethasone to bupivacaine in a nerve block after ACL surgery reduces long-term pain and opioid use.

## Contribution

This study shows that perineural dexamethasone reduces persistent postsurgical pain and opioid consumption after ACL reconstruction.

## Key findings

- Dexamethasone extended postoperative analgesia duration by 4 hours compared to the control group.
- The dexamethasone group had a 13% lower incidence of persistent postsurgical pain at 3 months.
- Opioid consumption, including meperidine and codeine, was significantly reduced in the dexamethasone group.

## Abstract

Pain is a protective response to noxious stimuli to prevent further damage. The surgical incision results in several events that lead to pain that outlasts its benefits. Persistent postsurgical pain (PPSP) is defined as “pain that persists for three months after surgical intervention.

To investigate the effect of dexamethasone as an adjuvant to adductor canal block on persistent postsurgical pain after ACL reconstruction.

Ninety patients who underwent arthroscopic reconstruction of the anterior cruciate ligament and who completed the study were randomly allocated into two groups. Forty-five patients in each group received ultrasound-guided adductor canal block at the end of surgery. G I (Dexa group): Forty-five patients received a 20 ml mixture of 0.25% bupivacaine and 8 mg dexamethasone (2 ml). G II (control group): Patients received a 20 ml mixture of 0.25% bupivacaine and 2 ml of normal saline.

No significant differences in demographic data, intraoperative hemodynamics or surgery duration were detected between the two groups. The duration of postoperative analgesia was significantly longer in the dexamethasone group (10 h ± 3 vs. 6 h ± 1) than in the control group. Additionally, 24 h postoperative consumption of meperidine was significantly lower in the dexamethasone group (65 ± 23 vs. 104 ± 27) than in the control group. Postoperative VAS scores at 6 and 12 h were also lower in the dexamethasone group than in the control group. Three-month follow-up revealed a significantly lower incidence of PPSP in the dexamethasone group (20% versus 33% in the control group). Moreover, the severity of PPSP was significantly lower in the dexamethasone group than in the control group. Additionally, Codeine consumption was significantly lower in the dexamethasone group than in the control group.

Perineural dexamethasone in ultrasound-guided adductor canal block reduced the severity of PPSP and opioid analgesia consumption in the first three months following arthroscopic reconstruction of the ACL.

The study was registered on clinical trial registration (NCT04631822) in October 2020.

The online version contains supplementary material available at 10.1186/s12871-025-02921-6.