title: The effect of Lidocaine on the viability of cultivated mature human cartilage cells: an in vitro study.
abstract: OBJECTIVE
  More and more orthopedic procedures are performed in an outpatient setting. A commonly used strategy in pain management is the intra-articular injection of local anesthetics. Recent attention has been drawn to their possible toxic effect on chondrocytes. Local anesthetics, and in particular Lidocaine, are also used for diagnostic joint infiltrations. A controlled laboratory study was performed to investigate the possible toxic effect of Lidocaine on human articular chondrocytes.
  
  
  METHODS
  Mature human articular chondrocytes were harvested from the knees of human tissue donors or patients undergoing total knee replacement. The cells were exposed to Lidocaine 1 and 2% with and without epinephrine and to a saline 0.9% control group, with variable exposure times in different experiments. The activity and viability of the cells were assessed by lactate dehydrogenase activity, interleukin-6 production and a live/dead cell count.
  
  
  RESULTS
  After a 1-h exposure, devastating results were seen for Lidocaine 1, 2 and 2% with epinephrine showing cell death rates of 91, 99 and 97%, respectively, compared with 26% in the saline control group (P-values of 0.004, 0.010, 0.006, respectively). Exposing the chondrocytes to a 50/50 mixture of culture medium and local anesthetics substantially decreased cytotoxicity but still showed high toxicity when compared with the saline group (90% dead cells for Lidocaine 2%, P = 0.047). Lidocaine also showed a time-dependent cytotoxicity with gradually more dead cells after exposure for 15, 30 or 60 min.
  
  
  CONCLUSIONS
  In vitro, local anesthetics containing Lidocaine are significantly more toxic to mature human articular chondrocytes than a saline 0.9% control group. The effect of Lidocaine on the viability of human chondrocytes in vivo needs further investigation. However, based on our in vitro results, cautious use of intra-articular Lidocaine in clinical practice is recommended.
authors.affiliation: Department of Anesthesia, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium. tom.jacobs@ugent.be
authors.forename: Tom F
authors.initials: TF
authors.lastname: Jacobs
authors.forename: Pieter S
authors.initials: PS
authors.lastname: Vansintjan
authors.forename: Nathalie
authors.initials: N
authors.lastname: Roels
authors.forename: Sofie S
authors.initials: SS
authors.lastname: Herregods
authors.forename: Gust
authors.initials: G
authors.lastname: Verbruggen
authors.forename: Luc L
authors.initials: LL
authors.lastname: Herregods
authors.forename: Karl F
authors.initials: KF
authors.lastname: Almqvist
mesh_terms: D000368:Aged; D000779:Anesthetics, Local / Q000633:toxicity*; D002470:Cell Survival / Q000187:drug effects; D019902:Chondrocytes / Q000187:drug effects* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D015850:Interleukin-6 / Q000378:metabolism; D045022:Lactate Dehydrogenases / Q000378:metabolism; D008012:Lidocaine / Q000633:toxicity*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013997:Time Factors
chemical_list: D000779:Anesthetics, Local; D015850:Interleukin-6; D008012:Lidocaine; D045022:Lactate Dehydrogenases