The Effect of Intra-articular Magnesium Sulfate on Postoperative Acute Pain in Knee Arthroscopy

Magnesium as an inorganic ion has several products containing it and has a number of therapeutic properties. A very common product, magnesium-sulfate has been proven in field of anesthesiology. This study looks at the effect of intra-articular injection of magnesium-sulfate on acute pain following knee surgery for diagnostic arthroscopy in patients undergoing general anesthesia.

60 patients were selected and divided randomly to 2 groups in this double-blind, randomized, placebo-controlled clinical trial. All anesthesia and surgery methods were the same in both groups. One group received intra-articular magnesium sulfate and the second group received the same volume of placebo. Postoperative pain scores were checked at the 1st, 3rd, 6th, 12th and 24th hours after the operation by a Visual Analog Scale (VAS) pain assessment scoring system. To present the results Mean (±SD) was used and the P-value less than 0.05 were considered statistically significant.

There was no statistically significant difference between the 2 groups for basic variables. Pain reported by the first group who received intra-articular magnesium sulfate solution was significantly less at the 1st hour postoperatively, than the other group (8.7±1.05 vs 5.53±1.91, respectively). Also, at the 6th and 12th hours postoperatively, the difference was significant (p<0.0001); but it was not at the 2nd 18th and 24th hours, postoperatively, in comparison to the group who received placebo (p>0.3).

in patients undergoing general anesthesia for arthroscopic knee surgery, intra-articular magnesium sulfate solution significantly reduced pain in the first few hours after the surgery.