PURPOSE
The aim of this study is to analyze the efficacy of the use of a combined infiltration between popliteal artery and knee capsule (IPACK) anesthetic block together with selective saphenous nerve block, versus local infiltration with anesthetic in knee replacement surgery.
METHODS
A retrospective observational study was performed. There were reviewed 312 patients who underwent primary total knee prosthesis at our hospital between January 2019 and December 2022, regardless of the reason for the surgical indication. Between January 2019 and November 2021, 207 patients were performed local intraarticular anesthesia (LIA) during the surgery. Since November 2021 to December 2022, 105 patients received the combined nerve blocks (IPACK + ACB group). The average age in the LIA group was 72.9 years while in the blocks group it was 70.4 years. There were 44% of men in the LIA group and 53.3% in the blocks group.
The primary outcome was the presence of poorly controlled pain that requires opioid analgesic rescue in the postoperative period. Secondary outcomes included pain scores measured using the visual analog scale (VAS), range of motion assessed with a goniometer and hospital length stay.
RESULTS
There were no significant differences in age or sex patient distribution between the two groups.
Only one patient treated with anesthetic blocks required rescue analgesia with minor opioids. Patients treated with LIA required treatment with minor opioids in 28.5% of cases. There were not statistically significant differences (p = 0.0964) between VAS in the LIA group and in the blocks group in the first 24h, although patients treated with LIA presented less elevated VAS data (mean 2.3 versus 2.7). The range of motion was slightly greater (4.6º, statistically significant data, < 0.05) in the blocks group. There were statistically significant differences in terms of hospital stay (2.4 days in the blocks group and 2.8 days in the LIA group (p < 0.05).
CONCLUSION
In our series patients treated with anesthetic blocks showed better results with similar control of postoperative pain. However, more studies would be needed.