Effect of levobupivacaine on articular chondrocytes: an in-vitro investigation.

BACKGROUND

Intra-articular injection of local anaesthetics is a technique commonly used to enhance postoperative analgesia following arthroscopic surgery. However, the potential for cartilage damage due to toxicity of intra-articular local anaesthetics is a concern. Most studies indicate that the toxic effect is drug and time dependent.

OBJECTIVES

The objective of this study is to compare the in-vitro chondrotoxic effect of levobupivacaine on human cartilage with saline and bupivacaine.

DESIGN

An experimental study.

SETTING

University hospital.

PARTICIPANTS

Adult patients undergoing knee surgery.

INTERVENTIONS: Human articular cartilage was harvested and removed from five patients during knee replacement surgery. Chondrocytes were cultured and divided into three groups exposed to bupivacaine 0.5%, levobupivacaine 0.5% or physiological saline for 15, 30 or 60 min.

MAIN OUTCOME MEASURES: Viability of human cartilage cells after contact with the different study drugs at different durations of exposure using two techniques: live/dead cell viability flow cytometry analysis and trypan blue exclusion assay.

RESULTS

At 1 h of exposure, chondrocyte mortality in cartilage explants was significantly greater after treatment with levobupivacaine or bupivacaine than with saline (25.9% ± 14.1, 20.7% ± 10.4 and 9.6% ± 5.4, respectively). No differences between groups were found when exposure to the experimental drug was limited to 15 or 30 min.

CONCLUSION

In-vitro 0.5% levobupivacaine is more chondrotoxic than saline in human articular cartilage after 1 h of exposure. Bupivacaine seems to be less chondrotoxic than levobupivacaine. With shorter exposures, no clear chondrotoxic effect was shown.