Abstracts Posters SICOT-SOF meeting Gothenburg 2010 _2_

Poster
Topic: General Orthopaedics
Abstract number: 26479
MAGNESIUM ATTENUATES LOCAL ANAESTHETIC TOXICITY TO CULTURED
HUMAN CHONDROCYTES
Joseph BAKER 1 , Damien BYRNE 2 , Pauline WALSH 1 , Kevin MULHALL 3
1 University College Dublin, Dublin (IRELAND), 2 Orthopaedic Research and
Innovation Foundation, Dublin (IRELAND), 3 Mater Misericordiae University Hospital,
Dublin (IRELAND)
Introduction: Local anaesthetic (LA) has a potentially detrimental effect on human
chondrocytes. Magnesium, an NMDA receptor-antagonist, may be an alternative
intra-articular analgesic agent. We aimed to report the effect of commonly used LA
on chondrocyte viability and also report on the effect of adding magnesium to the LA.
Methods: Human chondrocytes were exposed to either lignocaine (0.5, 1, 2%),
levobupivacaine (0.125, 0.25, 0.5%), bupivacaine (0.125, -.25, 0.5%) or ropivacaine
(0.1875, 0.375, 0.75%) for 15 minutes. Cells were also exposed to a local anesthetic
agent with the addition of magnesium (10, 20, or 50%). Cells exposed to media or
saline served as controls. MTS assay was used to assess cell viability 24-hours after
exposure. Results: One-way ANOVA showed an expected dose response in all LA
groups with the exception of lignocaine. Magnesium alone was no more toxic than
normal saline (P>0.3). 50% magnesium showed similar effect on cell viability to the
least toxic local anaesthetic (lignocaine 1%, P=0.31). The addition of magnesium to
the local anesthetic agents resulted in greater cell viability than when cells were
treated with the respective local anaesthetic alone (lignocaine (P=0.033),
levobupivacaine (P=0.007), bupivacaine (P