Lidocaine exhibits dose- and time-dependent cytotoxic effects on bovine articular chondrocytes in vitro.
BACKGROUND
Intra-articular lidocaine is commonly used.


OBJECTIVE
This study was conducted to determine whether short-term exposures to 1% and 2% lidocaine are toxic to articular chondrocytes, whether this is due to pH, and whether an intact articular surface is protective.


METHODS
Controlled laboratory study.


METHODS
Fresh bovine articular chondrocytes in alginate bead cultures were treated with 1% or 2% lidocaine or buffered saline (pH 7.4, 7.0, and 5.0) for 15, 30, or 60 minutes. Chondrocytes were then analyzed for viability by flow cytometry 1 hour, 1 day, and 1 week later. Bovine osteochondral cores with and without the superficial 1 mm of cartilage removed were submerged in either 0.9% saline (pH 7.4) or in 1% or 2% lidocaine for 30 minutes and assessed for viability using fluorescent microscopy.


RESULTS
Chondrocyte viability decreased after just 15-minute exposures to 1% lidocaine. Longer exposures to 1% and 2% lidocaine further reduced chondrocyte viability. Chondrotoxicity of 2% lidocaine was greater than 1% lidocaine. There was no difference in chondrocyte viability after exposures to saline solutions of pH 7.4, 7.0, or 5.0. An intact articular surface did not affect lidocaine's chondrotoxic effects.


CONCLUSIONS
Results show dose- and time-dependent cytotoxic effects of lidocaine on bovine articular chondrocytes. Reduction of pH alone did not decrease chondrocyte viability, and the intact articular surface was not protective.


CONCLUSIONS
Although lidocaine chondrotoxicity was less than previously reported with bupivacaine, these observations suggest that local anesthetics as a class of drugs may negatively affect articular cartilage.
Cartilage Restoration Laboratory, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA.
John C
JC
Karpie
Constance R
CR
Chu
D000779:Anesthetics, Local / Q000494:pharmacology*; D000818:Animals; D002358:Cartilage, Articular / Q000187:drug effects*; D002417:Cattle; D016923:Cell Death / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D019902:Chondrocytes / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D006863:Hydrogen-Ion Concentration; D008012:Lidocaine / Q000494:pharmacology*; D012965:Sodium Chloride; D012996:Solutions; D013997:Time Factors
D000779:Anesthetics, Local; D012996:Solutions; D012965:Sodium Chloride; D008012:Lidocaine