Intra-articular use of 0.5% bupivacaine is common in arthroscopic surgery. This study was conducted to test the hypotheses that (1) 0.5% bupivacaine is toxic to articular chondrocytes, and (2) the intact articular surface protects chondrocytes from the effects of short-term exposure to 0.5% bupivacaine.
Freshly isolated bovine articular chondrocytes were prepared into alginate bead cultures and were treated with 0.5% bupivacaine solution or 0.9% saline for 15, 30 or 60 minutes, washed, and returned to growth media. Chondrocytes were recovered from alginate 1 hour, 1 day, and 1 week after bupivacaine exposure; they were fluorescently labeled to identify apoptotic and dead cells and were analyzed by flow cytometry. Twelve osteochondral cores were harvested from bovine knees. The superficial 1 mm of cartilage was removed from 6 cores (top-off). Intact and top-off cores were submerged in 0.9% saline or 0.5% bupivacaine solution for 30 minutes and then maintained in chondrocyte growth media for 24 hours. Live-cell/dead-cell fluorescent imaging was assessed using confocal microscopy.
Greater than 99% chondrocyte death/apoptosis was observed in all bupivacaine-exposed alginate bead cultures compared with 20% cell death in saline-treated controls (P < .05). Osteochondral cores with intact surfaces treated with 0.5% bupivacaine showed 42% dead chondrocytes. When the articular surface was removed, 0.5% bupivacaine resulted in increased cell death, with 75% dead chondrocytes (P < .05).
Results show that 0.5% bupivacaine solution is cytotoxic to bovine articular chondrocytes and articular cartilage in vitro after only 15 to 30 minutes' exposure. The intact bovine articular surface has some chondroprotective effects.
Because healthy chondrocytes are important for maintenance of the cartilage matrix, chondrocyte loss may contribute to cartilage degeneration. This study shows a cytotoxic effect of 0.5% bupivacaine solution on bovine articular chondrocytes in vitro. Although these results cannot be directly extrapolated to the clinical setting, the data suggest that caution should be exercised in the intra-articular use of 0.5% bupivacaine.
"Several animal-based studies have supported the concept that prolonged exposure to local anesthetics (bupivacaine or lidocaine) damages articular cartilage (Piper et al., 2011; Matsen & Papadonikolakis, 2013). Ex vivo studies suggesting chondrotoxicity have used models in which the bupivacaine concentration is 5 mg/mL (0.5%), and/or in which the bupivacaine exposure is prolonged (e.g. 1 h to 3 days) (Chu et al., 2006; Gomoll et al., 2006; Piper & Kim, 2008; Anz et al., 2009; Bogatch et al., 2010; Dragoo et al., 2010; Hennig et al., 2010). However, the actual local bupivacaine concentration and duration of exposure to chondrocytes after intra-articular injection are unknown. "
[Show abstract][Hide abstract] ABSTRACT: Intra-articular bupivacaine helps alleviate pain in animals receiving joint surgery, but its use has become controversial as ex vivo studies have illuminated the potential for chondrotoxicity. Such studies typically involve cell cultures incubated in solutions containing high bupivacaine concentrations for long durations. The aim of this study was to measure the actual synovial fluid bupivacaine concentrations after intra-articular injection. Eight healthy beagles with normal stifles and 22 large and giant-breed dogs with stifle osteoarthritis (OA) were treated with a single intra-articular injection of bupivacaine (1 mg/kg) into a stifle. Joint fluid samples were taken from the treated stifle immediately after injection and 30 min after injection and analyzed for bupivacaine concentrations. Immediately after injection, the median bupivacaine concentrations in normal and OA stifles were 3.6 and 2.5 mg/mL, respectively. Thirty minutes after injection, bupivacaine concentrations in normal and OA stifles were 0.4 and 0.6 mg/mL, respectively. These results provide insight into the pharmacokinetics of bupivacaine after injection into a joint. Given its immediate dilution and rapid drop in synovial fluid concentration, bupivacaine is unlikely to damage chondrocytes when administered as a single intra-articular injection.
Journal of Veterinary Pharmacology and Therapeutics 09/2014; 38(1). DOI:10.1111/jvp.12158 · 1.19 Impact Factor
"Furthermore, we cannot comment on the average time that these chemicals would normally come in contact with IVD cells in clinical situations. However, it has been shown that cell viability after exposure to bupivacaine is greater in intact bovine articular cartilage compared with that of chondrocytes suspended in alginate, suggesting that the natural native matrix structure may provide some protection from local anesthetic exposure . The NP cells from healthy human IVD cells may be less susceptible to anesthetic agents than those from degenerated IVDs. "
[Show abstract][Hide abstract] ABSTRACT: Discography and discoblock are imaging procedures used to diagnose discogenic low back pain. Although needle puncture of the intervertebral disc (IVD) itself induces disc degeneration, the agents used in these procedures may also have harmful effects on IVD cells. The purpose of this study was to analyze whether radiocontrast agents and local anesthetic agents have detrimental effects on human nucleus pulposus (NP) cells.
Healthy human NP cells were cultured for 7 days in three-dimensional (3D) cell-alginate bead composites, and were then exposed to clinically relevant doses of a radiocontrast agent (iotrolan) or local anesthetic (lidocaine or bupivacaine). Cell viability and apoptosis were measured by confocal microscopy and flow cytometry. On the basis of caspase expression profiles, the apoptotic pathways activated by the agents were identified by Western blot analysis.
The radiocontrast agent iotrolan did not affect NP cell viability or induce apoptosis. In contrast, both the anesthetic agents significantly decreased cell viability and increased the apoptotic cell number in a time- and dose-dependent manner. After 120 min, 2% lidocaine and 0.5% bupivacaine decreased percent live cells to 13% and 10%, respectively (p<0.05). The number of apoptotic cells was doubled by increasing lidocaine dosage from 1% to 2% (23% and 42%) and bupivacaine from 0.25% to 0.50% (25% and 48%) (p<0.05). Western blot analysis revealed that both anesthetic agents upregulated cleaved caspase-3 and caspase-8, whereas only bupivacaine upregulated cleaved caspase-9.
The present study demonstrates that iotrolan does not affect the viability of healthy human NP cells. In contrast, the two anesthetic agents commonly used in discography or discoblock may cause extensive damage to IVDs by inducing apoptotic cell death.
PLoS ONE 03/2014; 9(3):e92442. DOI:10.1371/journal.pone.0092442 · 3.23 Impact Factor
"However, bupivacaine has been found to be chondrotoxic in vitro and several studies have suggested a dose and time-dependent chondrotoxicity of bupivacaine.15-17 Furthermore, an apparently toxic effect of 0.5% bupivacaine on disc cells and articular chondrocytes in vitro has been reported.18 "
[Show abstract][Hide abstract] ABSTRACT: Purpose
Bupivacaine is commonly used for the treatment of back pain and the diagnosis of its origin. Nonunion is sometimes observed after spinal fusion surgery; however, whether the nonunion causes pain is controversial. In the current study, we aimed to detect painful nonunion by injecting bupivacaine into the disc space of patients with nonunion after anterior lumbar interbody fusion (ALIF) surgery for discogenic low back pain.
Materials and Methods
From 52 patients with low back pain, we selected 42 who showed disc degeneration at only one level (L4-L5 or L5-S1) on magnetic resonance imaging and were diagnosed by pain provocation on discography and pain relief by discoblock (the injection of bupivacaine). They underwent ALIF surgery. If the patients showed low back pain and nonunion 2 years after surgery, we injected bupivacaine into the nonunion disc space. Patients showing pain relief after injection of bupivacaine underwent additional posterior fixation using pedicle screws. These patients were followed up 2 years after the revision surgery.
Of the 42 patient subjects, 7 showed nonunion. Four of them did not show low back pain; whereas 3 showed moderate or severe low back pain. These 3 patients showed pain reduction after injection of bupivacaine into their nonunion disc space and underwent additional posterior fixation. They showed bony union and pain relief 2 years after the revision surgery.
Injection of bupivacaine into the nonunion disc space after ALIF surgery for discogenic low back pain is useful for diagnosis of the origin of pain.
Yonsei medical journal 03/2014; 55(2):487-92. DOI:10.3349/ymj.2014.55.2.487 · 1.29 Impact Factor
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