title: The viability of chondrocytes after an in vivo injection of local anaesthetic and/or corticosteroid: a laboratory study using a rat model.
abstract: This in vivo controlled laboratory study was performed to evaluate various intra-articular clinical injection regimes that might be less toxic than some in vitro studies suggest. We hypothesised that low-concentration, preservative-free, pH-balanced agents would be less toxic than high-concentration non-pH-balanced agents with preservatives, and that injections of individual agents are less toxic than combined injections. The left knees of 12- to 13-week-old Sprague-Dawley rats were injected once with eight different single agents, including low and high concentrations of ropivacaine and triamcinolone, alone and in combination, as well as negative and positive controls. The rats were killed at one week or five months, and live-dead staining was performed to quantify the death of chondrocytes. All injections except pH-balanced 0.2% ropivacaine combined with preservative-free 1 mg/ml triamcinolone acetonide resulted in statistically significant decreases in chondrocyte viability, compared with control knees, after one week and five months (p < 0.001). After one week there was no significant difference in viability between 0.2% and 0.5% ropivacaine; however, 4 mg/ml triamcinolone resulted in a lower viability than 1 mg/ml triamcinolone. Although many agents commonly injected into joints are chondrotoxic, in this in vivo study diluting preservative-free 10 mg/ml triamcinolone 1:9 in 0.2% pH-balanced ropivacaine resulted in low toxicity.
authors.affiliation: University of North Carolina, Orthopaedic Research Labs, 134B Glaxo Building. CB# 7546, 101A Mason Farm Rd. Chapel Hill, North Carolina 27599, USA.
authors.forename: M
authors.initials: M
authors.lastname: Sola
authors.affiliation: University of North Carolina, CB #7055, Bioinformatics Building, Chapel Hill, North Carolina 27599-7055, USA.
authors.forename: L
authors.initials: L
authors.lastname: Dahners
authors.affiliation: University of North Carolina, Orthopaedic Research Labs, 134B Glaxo Building. CB# 7546, 101A Mason Farm Rd. Chapel Hill, North Carolina 27599, USA.
authors.forename: P
authors.initials: P
authors.lastname: Weinhold
authors.affiliation: University of North Carolina, Orthopaedic Research Labs, 134B Glaxo Building. CB# 7546, 101A Mason Farm Rd. Chapel Hill, North Carolina 27599, USA.
authors.forename: A
authors.initials: A
authors.lastname: Svetkey van der Horst
authors.affiliation: University of North Carolina, Orthopaedic Research Labs, 134B Glaxo Building. CB# 7546, 101A Mason Farm Rd. Chapel Hill, North Carolina 27599, USA.
authors.forename: S
authors.initials: S
authors.lastname: Kallianos
authors.affiliation: University of Missouri Missouri Orthopaedic Institute, 1100 Virginia Avenue, DC953.00, Columbia, Missouri 65212, USA.
authors.forename: D
authors.initials: D
authors.lastname: Flood
mesh_terms: D000577:Amides / Q000008:administration & dosage*; D000779:Anesthetics, Local / Q000008:administration & dosage*; D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D019902:Chondrocytes / Q000187:drug effects* / Q000502:physiology*; D005260:Female; D005938:Glucocorticoids / Q000008:administration & dosage*; D007270:Injections, Intra-Articular; D023421:Models, Animal; D051381:Rats; D017207:Rats, Sprague-Dawley; D000077212:Ropivacaine; D014221:Triamcinolone / Q000008:administration & dosage*
chemical_list: D000577:Amides; D000779:Anesthetics, Local; D005938:Glucocorticoids; D014221:Triamcinolone; D000077212:Ropivacaine
keywords: Chondrocytes; joint injection; triamcinolone; ropivacaine