Chondrotoxic effect of intraarticular bupivacaine administration

Abstract

We read the article ‘‘The comparison of intraarticular morphine-bupivacaine and tramadol-bupivacaine in postoperative analgesia after arthroscopic anterior cruciate ligament reconstruction’’ by Hosseini et al. [5] recently published in this journal with great interest. The article describes a randomised, double blind, controlled trial study of ASA I–II patients undergoing arthroscopic ACL reconstruction performed under general anaesthesia who were given a combination of drugs intraarticularly for postoperative analgesia and pain control. Study was approved by the research ethics committees in Shahid Sadoughi University of Medical Sciences, and written informed consents were obtained from 60 male patients. Patients were randomly allocated into three groups. The MB group (n = 20) received 10 mg morphine and 0.5 % bupivacaine, the TB group (n = 20) received 100 mg tramadol and 0.5 % bupivacaine and the control group (n = 20) received 20 ml of isotonic saline intraarticularly at the end of the operation. The authors concluded that intraarticular morphine–bupivacaine combination provides more effective pain relief, longer analgesic duration, less supplemental analgesic postoperative requirements, shorter unassisted ambulation and discharge time when compared to intraarticular tramadol–bupivacaine injection and isotonic saline after ACL reconstruction arthroscopy. In side effects assesment, none of the patients had respiratory depression, and there was no significant difference between the groups in terms of nausea and vomiting. It is interesting that there was no mention or even concern of chondrotoxic effect of bupivacaine in this article. Chu et al. [4] have shown in 2006 that 0.5 % bupivacaine solution is cytotoxic to bovine articular chondrocytes and articular cartilage in vitro after only 15–30 min exposure. The authors suggested caution in the intraarticular use of 0.5 % bupivacaine. Toxicity of bupivacaine was demonstrated on human articular chondrocytes too [6]. Piper et al. compared the in vitro viability after exposure of full-thickness knee cartilage explants and cultured chondrocytes to 0.9 % normal saline solution, 0.5 % ropivacaine and 0.5 % bupivacaine, respectively, after 30 min. Chondrocyte viability in cartilage explants and the viability of cultured chondrocytes were significantly lower after treatment with bupivacaine as compared to ropivacaine. A few years later, in vivo animal study was conducted to determine whether a single intraarticular injection of 0.5 % bupivacaine results in chondrocyte morbidity and rapid chondrolysis [3]. Reduced chondrocyte density without cartilage tissue loss 6 months after a single intraarticular injection of 0.5 % bupivacaine suggested bupivacaine toxicity. The effects of bupivacaine were milder than those of an injection of 0.6 % monoiodoacetate (positive control), which resulted in chondrolysis over the same time period. As the risk of chondrotoxic effect of bupivacaine clearly exists, we would like to know why the adverse effect of bupivacaine was completely ignored in the article. Unfortunately, period of time when the study has been conducted was not specified in the Hosseini et al. [5] article. We are curious if the authors were aware of the adverse chondrotoxic effect of bupivacaine and if it was mentioned in the N. V. Filipcic (&) Department of Anaesthesiology and Intensive Care, University Hospital Merkur, Zagreb University, Zajceva 19, 10000 Zagreb, Croatia e-mail: natashav7@gmail.com