Local anaesthetics and chondrotoxicty: What is the evidence?

Cytotoxicity of local anaesthetics and protective effects of platelet rich plasma on equine tenocytes: An in vitro study

Local anaesthetics (LAs) can have detrimental effects on rat, bovine, canine, and human tendon tissues and cells. Currently, there has been no available data on the impact of these drugs on equine tenocytes. Even if LA injection for managing painful tendon conditions in horses is limited, it is usually used via intra-articular, intrasynovial, perineural, and intrathecal as well as for lameness examinations. In this in vitro study, the cytotoxic effects of LAs, including lidocaine, mepivacaine, and bupivacaine on equine tenocytes, in the presence and absence of platelet rich plasma (PRP), were investigated. PRP accelerates tissue healing and can exert cytoprotective effects on different cell types exposed to different stressful conditions, including drugs. Results indicated that the exposure to LAs significantly reduced tenocytes viability in dose- and time-dependent manners while PRP was able to counteract their cytotoxic effects. Furthermore, microscopy and flow cytometry analyses revealed apoptosis and necrosis in equine tenocytes exposed to these drugs, that were both reduced when PRP was in the medium. These findings highlight the importance of considering the tenocyte toxicity associated with intrathecal and intraneural LA injections, as they might affect tenocytes or reduce the efficacy of associated therapies. Moreover, this study also highlights the protective effects of PRP, which could make LA injections safer.

Computational Metrics Can Provide Quantitative Values to Characterize Arthroscopic Field of View

Purpose

The purpose of this study was to determine the inter-rater reliability of arthroscopic video quality, determine correlation between surgeon rating and computational image metrics, and facilitate a quantitative methodology for assessing video quality.

Methods

Five orthopaedic surgeons reviewed 60 clips from deidentified arthroscopic shoulder videos and rated each on a four-point Likert scale from poor to excellent view. The videos were randomized, and the process was completed a total of three times. Each user rating was averaged to provide a user rating per clip. Each video frame was processed to calculate brightness, local contrast, redness (used to represent bleeding), and image entropy. Each metric was then averaged over each frame per video clip, providing four image quality metrics per clip.

Results

Inter-rater reliability for grading video quality had an intraclass correlation of .974. Improved image quality rating was positively correlated with increased entropy (.8142; P < .001), contrast (.8013; P < .001), and brightness (.6120; P < .001), and negatively correlated with redness (−.8626; P < .001). A multiple linear regression model was calculated with the image metrics used as predictors for the image quality ranking, with an R-squared value of .775 and root mean square error of .42.

Conclusions

Our study demonstrates strong inter-rater reliability between surgeons when describing image quality and strong correlations between image quality and the computed image metrics. A model based on these metrics enables automatic quantification of image quality.

Clinical Relevance

Video quality during arthroscopic cases can impact the ease and duration of the case which could contribute to swelling and complication risk. This pilot study provides a quantitative method to assess video quality. Future works can objectively determine factors that affect visualization during arthroscopy and identify options for improvement.

Comparison of in vitro and in vivo Toxicity of Bupivacaine in Musculoskeletal Applications

The recent societal debate on opioid use in treating postoperative pain has sparked the development of long-acting, opioid-free analgesic alternatives, often using the amino-amide local anesthetic bupivacaine as active pharmaceutical ingredient. A potential application is musculoskeletal surgeries, as these interventions rank amongst the most painful overall. Current literature showed that bupivacaine induced dose-dependent myo-, chondro-, and neurotoxicity, as well as delayed osteogenesis and disturbed wound healing in vitro. These observations did not translate to animal and clinical research, where toxic phenomena were seldom reported. An exception was bupivacaine-induced chondrotoxicity, which can mainly occur during continuous joint infusion. To decrease opioid consumption and provide sustained pain relief following musculoskeletal surgery, new strategies incorporating high concentrations of bupivacaine in drug delivery carriers are currently being developed. Local toxicity of these high concentrations is an area of further research. This review appraises relevant in vitro, animal and clinical studies on musculoskeletal local toxicity of bupivacaine.

Neurotropin protects rotator cuff tendon cells from lidocaine-induced cell death

Background

Local anesthetics often are used in rotator cuff tears as therapeutic tools, although some cases have reported that they have detrimental effects. Neurotropin (NTP) is used widely in Japan as a treatment for various chronic pain conditions and is shown to have protective effects on cartilage and nerve cells. In this study, we investigated the protective effect of NTP against lidocaine-induced cytotoxicity.

Methods

Tenocytes from rotator cuff tendons were incubated with lidocaine, NTP, lidocaine with NTP, and a control medium. Cell viability was evaluated using the WST-8 assay. Cell apoptosis was detected via annexin V staining using flow cytometry. The expression of BCL-2 and cytochrome c, which are involved in the intrinsic mitochondrial pathway of apoptosis, was evaluated via Western blotting and immunohistochemical staining.

Results

In the cell viability assay, lidocaine decreased cell viability in a dose-dependent manner, and NTP did not affect cell viability. Moreover, NTP significantly inhibited the cytotoxic effect of lidocaine. The flow cytometry analysis showed that lidocaine significantly induced apoptosis in tenocytes, and NTP considerably inhibited this lidocaine-induced apoptosis. Western blotting experiments showed that lidocaine decreased the protein expression of BCL-2, and that NTP conserved the expression of BCL-2, even when used with lidocaine. Immunohistochemical staining for cytochrome c showed that 0.1% lidocaine increased cytochrome c-positive cells, and NTP suppressed lidocaine-induced cytochrome c expression.

Conclusions

NTP suppresses lidocaine-induced apoptosis of tenocytes by inhibiting the mitochondrial apoptotic pathway. Intra-articular/ bursal injection of NTP with lidocaine could protect tenocytes in rotator cuff tendons against lidocaine-induced apoptosis.

Toxicity of tranexamic acid (TXA) to intra-articular tissue in orthopaedic surgery: a scoping review

PURPOSE

Intra-articular administration of tranexamic acid (TXA) in orthopaedic arthroplasty and arthroscopic procedures has become increasingly common over the past decade. However, several recent reports have shown that TXA has the potential to be cytotoxic to cartilage, tendon and synovium. Our aim was to review the literature for evidence of toxic effects from TXA exposure to intra-articular tissue.

METHODS

A scoping review methodology was used to search for studies assessing the toxic effects of TXA exposure to intra-articular tissues. MEDLINE, EMBASE, SCOPUS and The Cochrane Library were searched. Relevant information was extracted and synthesis of the retrieved data followed a basic content analytical approach.

RESULTS

A total of 15 laboratory studies were retrieved. No clinical studies reporting a toxic effect of TXA on intra-articular tissue were identified in our search. Studies were analysed according to species of origin, tissue of origin and study setting (in vitro, ex vivo, or in vivo). There was increasing cytotoxicity to chondrocytes, tenocytes, synoviocytes and periosteum-derived cells with TXA concentrations beyond 20 mg/ml. Monolayer cell cultures appear more susceptible to TXA exposure, than three-dimensional and explant culture models. In vivo studies have not demonstrated a major toxic effect.

CONCLUSIONS

Current evidence suggests a dose-dependent toxic effect on cartilage, tendon, and synovial tissue. Concentrations of 20 mg/ml or less are expected to be safe. There is a significant body of evidence to suggest the need for caution with intraarticular administration of TXA. There is a need for further human clinical trials in order to clarify the long-term safety of TXA topical application.

Intra-articular use of analgesic/antinflammatory drugs in dogs and horses

Joint pain is a major cause of lameness in animals such as horses and dogs, and it may affect their athletic performance and quality of life. The intra-articular administration of analgesic/antinflammatory drugs is a common practice in veterinary medicine, for both lameness diagnosis and joint pain management. It is used either perioperatively, such as in animals undergoing arthroscopy/arthrotomy, and in osteoarthritic animals. However, evidence regarding efficacy and safety of each drug is limited, and controversies persist in these areas. In particular, it is often uncertain whether a defined treatment is effective by simply relieving the symptomatic pain associated with the joint disease, or whether it has a positive effect on the joint environment. Moreover, there is still much hesitation about treatments for joint diseases, related to the time of their application for the best outcome, and to any possible deleterious side effects. This article includes a review of the literature concerning the main analgesic/antinflammatory drugs used intra-articularly for managing acute and chronic joint pain/inflammation in dogs and horses. Three main issues for each class of drugs are considered, including clinical efficacy, pharmacokinetics, and local cytotoxic effects.

How does intraarticular dexmedetomidine injection effect articular cartilage and synovium? An animal study

Background

Intraarticular injections are widely used to provide pain relief after arthroscopic procedures and minimize the use of opioids. Dexmedetomidine has been proven to potentiate pain relief and postpone the demand for the first analgesic drug when it is used intraarticularly following arthroscopic knee procedures. However, the effects of dexmedetomidine on articular structures have not yet been evaluated. Our aim was to determine the effects of intraarticular dexmedetomidine injection on articular structures such as cartilage and synovium.

Design

Animal study.

Methods

Twenty adult rats (Sprague-Dawley) were enrolled in the study. Following appropriate aseptic and anesthetic conditions, dexmedetomidine (100 mcg/ml) (0.25 ml) was injected into the right knee joint (the study group) and normal saline solution (0.25 ml) into the left knee joint (the control group) of the rats. Four rats were sacrificed from each group on days 1, 2, 7, 14, and 21, and knee joint samples were obtained. Histologists evaluated the articular and periarticular regions and the synovium using histological sections, and a five-point scale was used to grade the inflammatory changes in a blinded manner.

Results

The groups were found to be similar in terms of median congestion scores, edema and inflammation scores, subintimal fibrosis, neutrophil activation and cartilage structure at each of the time intervals.

Conclusion

In our placebo-controlled, in vivo trial, the intraarticular use of dexmedetomidine seemed to be safe with respect to the studied histopathological parameters. However, complementary studies investigating the histopathological effects, analgesic dosage and adverse effects of dexmedetomidine on damaged articular structure models are needed.

Local Anesthetics: Pharmacology and Special Preparations

Local anesthetics are the only class of drugs that can block transduction and transmission of nociception. Physical properties, mechanism of action, and pharmacokinetics of this class of drugs are reviewed in this article. The clinical use, such intravenous administration of lidocaine, and local and systemic toxic effects are covered. A review of current studies published in the human and veterinary literature on lidocaine patches (Lidoderm) and liposomal bupivacaine (Experal and Nocita) are discussed.

Local Anesthetics' Toxicity toward Human Cultured Chondrocytes: A Comparative Study between Lidocaine, Bupivacaine, and Ropivacaine

OBJECTIVE

In orthopedic joint injection, the most frequently used local anesthetics are ropivacaine, bupivacaine, and 1% or 2% lidocaine. The aim of this study was to examine effects of these various anesthetics on the viability of human chondrocytes. Our hypothesis was that all local anesthetics tested damage human chondrocytes in vitro.

METHODS

Primary human chondrocytes were isolated and cultured from 6 donated human knee joints (mean age of donors 61.2 years). Local anesthetics were added to these cultures. Toxicity analysis was performed by visualization of cell structure using light microscopy. Determination of vital chondrocytes was performed by use of a Casy cell counter. Chondrocytes' cell death was examined by fluorescence microscopy and an XTT ELISA assay.

RESULTS

Light microscope and fluorescence microscope data revealed a defect cell structure and increased number of dead cells after addition of 1% or 2% lidocaine and bupivacaine but not ropivacaine. We were able to show an increased level of XTT activity after treatment with bupivacaine, 2% lidocaine or ropivacaine. The count of vital chondrocytes was significantly decreased after treatment with bupivacaine, 1% or 2% lidocaine, and ropivacaine.

CONCLUSIONS

The data show that treatment with local anesthetics induces cell damage of human chondrocytes in vitro. Ropivacaine seems to be a local anesthetic with the lowest toxic potential on human chondrocytes, a feature that may favor its preference for use in joint injection.

Viability of Equine Chondrocytes After Exposure to Mepivacaine and Ropivacaine In Vitro

Chondrocyte health is altered when exposed to local anesthetics, raising concerns as to the long-term effects of local anesthetics intra-articularly for diagnosis and analgesia. To investigate the drug with the lowest toxic potential, the effect of ropivacaine and mepivacaine on chondrocytes was evaluated. Articular cartilage from normal metacarpophalangeal joints of five equine cadaver specimens was used to establish chondrocyte cultures. Following seven days, chondrocytes were exposed to standard culture medium (DMEM), ropivacaine 7.5 mg/ml (ROP7.5), ropivacaine 10 mg/ml (ROP10), mepivacaine 20 mg/ml (MEP20), mepivacaine 30 mg/ml (MEP 30), and 0.9% saline solution (SAL). Chondrocyte viability was evaluated by trypan blue exclusion, MTT, and flow cytometry via cellular staining with propidium iodide. No differences were observed between treatments following trypan blue exclusion assay. A difference was observed between DMEM and all other treatment groups (P < .0001) with a significant viability drop using the MTT assay. Mepivacaine 20 mg/ml and MEP30 exposure between showed greatest decrease in cellular viability compared to SAL, ROP7.5, and ROP10 (P < .0001). Cellular viability decreased as measured by flow cytometry in all groups compared to DMEM and ROP7.5 (P < .02). Interestingly, the trypan blue, MTT, and flow cytometry assays yielded different results. Although there was no difference using trypan blue, MTT demonstrated that ropivacaine-treated cells had lower viability than DMEM, and cytometry found that ROP7.5 did not differ from DMEM. Results in vitro suggest that short-term exposure to ropivacaine may result in less chondrotoxicity than mepivacaine. In vivo studies are warranted investigating long-term effects of local anesthetics on equine articular cartilage.

Protective effects of platelet-rich plasma against lidocaine cytotoxicity on canine articular chondrocytes

Background

Lidocaine (LD) is one of the most commonly used local anesthetics for performing arthroscopic surgery and managing of osteoarthritic pain in both human and veterinary medicine. However, over the last years, several studies have focused on the chondrotoxic effects of LD. In order to ensure that intra-articular lidocaine is safe to use, treatments aimed at mitigating chondrocyte death have recently been investigated. The aim of this study is to evaluate the possible protective effects of platelet-rich plasma (PRP) against LD cytotoxicity on canine articular chondrocytes.

Results

Articular canine chondrocytes, were exposed to 1% or 1.8% LD alone or in co-presence with 10% PRP for 30 min. In order to evaluate the effects of PRP pre-treatments, experiments were carried out on cells cultured in serum-free medium-or in medium supplemented with 10% PRP or 10% fetal bovine serum. Cell viability was evaluated by methyl thiazolyl tetrazolium assay and cell apoptosis was analyzed by flow cytometry using annexin V-fluorescein isothiocyanate/propidium iodide. The results showed that LD significantly reduced canine chondrocytes viability, probably due to apoptosis induction. Pre-treatment or the co-presence of PRP in the media restored the number of viable chondrocytes. The PRP also seemed to protect the cells from LD-induced apoptosis.

Conclusions

Pre-treatments and/or the simultaneous administration of PRP reduced LD-induced cytotoxicity in canine chondrocytes. Further in vivo studies are required to determine whether PRP can be used as a save protective treatment for dogs receiving intra-articular LD injections.

Injection of tennis elbow: Hit and miss? A cadaveric study of injection accuracy

PURPOSE

Different injection therapies are used in the treatment of lateral epicondylitis (LE). Usually, the extensor carpi radialis brevis (ECRB) tendon is affected. Therefore, an injection should be aimed at the origin of this tendon. This study demonstrates the accuracy of manual injections in the treatment of LE.

METHODS

Ten surgeons have injected a cadaver elbow with acrylic paint, using the same injection technique (i.e. number of perforations, amount of injected fluid) that they in daily practice would use in the treatment of LE. After the injection, an arthroscopy and dissection of the elbow were performed. The injection technique and localization of acrylic paint were reported.

RESULTS

Only a third of the injections were (partially) localized in the ECRB tendon; 60 % were localized intra-articular.

CONCLUSION

Injections carried out manually for the treatment of LE are not accurate, resulting in the majority being localized intra-articular. For future research to the effect of injection therapy in the treatment of LE, it is important that injections should be performed in a reproducible and standardized way.

In vitro chondrocyte toxicity following long-term, high-dose exposure to Gd-DTPA and a novel cartilage-targeted MR contrast agent

OBJECTIVE

To determine the concentrations exhibiting toxicity of a cartilage-targeted magnetic resonance imaging contrast agent compared with gadopentetate dimeglumine (Gd-DT-PA) in chondrocyte cultures.

MATERIALS AND METHODS

A long-term Swarm rat chondrosarcoma chondrocyte-like cell line was exposed for 48 h to 1.0-20 mM concentrations of diaminobutyl-linked nitroxide (DAB4-DLN) citrate, 1.0-20 mM Gd-DTPA, 1.0 μM staurosporine (positive control), or left untreated. Cell appearance, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays of metabolic activity, quantitative PicoGreen assays of DNA content, and calcein-AM viability assays were compared.

RESULTS

At 1.0-7.5 mM, minimal decrease in cell proliferation was found for both agents. At all doses of both agents, cell culture appearances were similar after 24 h of treatment. At the higher doses, differences in cell culture appearance were found after 48 h of treatment, with dose-dependent declines in chondrocyte populations for both agents. Concentration-dependent declines in DNA content and calcein fluorescence were found after 48 h of treatment, but beginning at a lower dose of DAB4-DLN citrate than Gd-DTPA. Dose-dependent decreases in MTT staining (cell metabolism) were apparent for both agents, but larger effects were evident at a lower dose for DAB-DLN citrate. Poor MTT staining of cells exposed for 48 h to 20 mM DAB4-DLN citrate probably indicates dead or dying cells.

CONCLUSION

The minimal effect of the long-term exposure of model chondrocyte cell cultures to DAB4-DLN citrate and Gd-DTPA concentrations up to 7.5 mM (3x typical arthrographic administration) is supporting evidence that these doses are acceptable for MR arthrography. The findings are reassuring given that the experimental exposure to the contrast agents at sustained concentrations was much longer than when used clinically.

In vitro toxicity of local anaesthetics and corticosteroids on supraspinatus tenocyte viability and metabolism

Background/Objective

The purpose of this study was to evaluate supraspinatus tenocyte viability and metabolism in explants exposed to various local anaesthetics and corticosteroids. Our hypothesis was that the tendons exposed to these common injectates would have significantly decreased cell viability and metabolism compared with controls.

Methods

Supraspinatus tendon explants were obtained from dogs, placed in a culture media, and randomly assigned to one of the following groups: culture media only (control), 1% lidocaine, 0.5% lidocaine, 0.25% bupivacaine, 0.125% bupivacaine, 0.0625% bupivacaine, betamethasone acetate (5 mg), methylprednisolone acetate (40 mg), or triamcinolone acetonide (40 mg). Cell viability was determined on Days 1 and 7 after culture treatment using calcein AM (live cell) and Sytox Blue (dead cell) stains. Tissue metabolism was assessed on Days 1 and 7 using the resazurin blue metabolic assay. Significant differences were evaluated using a one-way analysis of variance with Tukey post hoc analysis.

Results

Compared with the controls, there were significant decreases in cell viability noted at Days 1 and 7 in tenocytes exposed to 1% lidocaine, betamethasone, and methylprednisolone. Significant decreases in cell metabolism were also noted at Days 1 and 7 in those groups. Treatment with 0.125% bupivacaine, 0.0625% bupivacaine, and triamcinolone demonstrated no decrease in cell viability or metabolism when compared with controls at any time point.

Conclusion

This data confirms that peritendinous injection of commonly used local anaesthetics and corticosteroids results in significant supraspinatus tenotoxicity in vitro. Further in vivo studies are required before making definitive clinical recommendations.

Does chondrolysis occur after corticosteroid-analgesic injections? An analysis of patients treated for adhesive capsulitis of the shoulder

BACKGROUND

Clinical studies using continuous infusions of local anesthetics and basic science studies that model injections of local anesthetics have shown chondrotoxicity. However, clinical studies do not exist that have assessed for the risk of chondrolysis in nonarthritic joints exposed to single or intermittent corticosteroid or analgesic injections. Currently, there are no data available to guide the clinician on the safety of using these injections in clinical practice.

MATERIALS AND METHODS

A retrospective review of patients treated for adhesive capsulitis of the shoulder with at least 1 intra-articular injection of a corticosteroid and anesthetic was performed. The inclusion criteria were a diagnosis of adhesive capsulitis and a minimum 2-year follow-up. Prospective follow-up was performed to obtain patient-determined outcome scores, range of motion, and radiographs to determine the presence of chondrolysis.

RESULTS

Fifty-six patients with a mean age of 52.5 ± 7.2 years were enrolled at a mean follow-up of 54 months. The mean number of injections performed was 1.5 ± 0.7 (range, 1-4). At final follow-up, the mean Western Ontario Osteoarthritis of the Shoulder score was 91.4% ± 14.2%; Disabilities of the Arm, Shoulder and Hand score, 6.7 ± 9.6; Shoulder Pain and Disability Index score, 7.4 ± 11.4; and Single Assessment Numeric Evaluation score, 92.7% ± 10.1%. The Shoulder Activity Score was 8.3 ± 4.7. Passive and active forward elevation, external rotation, internal rotation, and cross-body adduction showed no significant differences compared with the unaffected contralateral shoulder. There was no radiographic evidence of chondrolysis in any patient.

CONCLUSIONS

This study did not show chondrolysis in patients treated with an intra-articular corticosteroid and local anesthetic for adhesive capsulitis. The findings of this study do not support the cessation of using intra-articular analgesic-corticosteroid injections for the treatment of adhesive capsulitis.

LEVEL OF EVIDENCE

Level IV; Case Series; Treatment Study.

Epinephrine Diluted Saline-Irrigation Fluid in Arthroscopic Shoulder Surgery: A Significant Improvement of Clarity of Visual Field and Shortening of Total Operation Time. A Randomized Controlled Trial

PURPOSE

To determine the influence of epinephrine saline irrigation in therapeutic shoulder arthroscopy procedures on the clarity of arthroscopic view. Three subgroups were analyzed; (1) Bankart/SLAP repairs; (2) rotator cuff repairs; and (3) subacromial procedures without rotator cuff repair. Secondary objectives were to evaluate the influence on total operating time and potential cardiovascular adverse reactions.

METHODS

The design of the study was a prospective, randomized, double-blind controlled trial. A total of 101 patients were included. Pressure pump-controlled regular saline irrigation fluid was used in the control group. In the epinephrine group, epinephrine (0.33 mg/L) was added to the saline-irrigation fluid. Visual clarity was rated by a Numeric Rating Scale. Total operation time, total use of irrigation fluid, increases in pump pressure, heart rate, blood pressure, and electrocautery use were registered.

RESULTS

Visual clarity (P = .002) was significantly better and total operating time (P = .008) significantly shorter in the epinephrine group. Total irrigation fluid used was significantly lower in the epinephrine group (P = .001). The greatest effect on visual clarity and shortening of operation time up to 15 minutes was seen in Bankart and SLAP repairs. No significant effect of the addition of epinephrine on heart rate and blood pressure was observed.

CONCLUSIONS

The addition of epinephrine (0.33 mg/L) to irrigation fluid significantly improves visual clarity in most common types of therapeutic shoulder arthroscopy. A significant reduction in total operating time and use of irrigation fluid was observed. The greatest effect on visual clarity and shortening of operation time was seen in Bankart and SLAP group. Therefore, one of our initial hypotheses that the greatest effect would be observed in subacromial and rotator cuff repair procedures was not supported by the data presented. No cardiovascular adverse reactions were seen.

LEVEL OF EVIDENCE

Level 1, Randomized controlled trial.

In Vitro Toxicity of Local Anesthetics and Corticosteroids on Chondrocyte and Synoviocyte Viability and Metabolism

OBJECTIVE

There is growing concern that intra-articular injection of local anesthetic and/or corticosteroids may cause significant morbidity, including potential toxicity to chondrocytes and synoviocytes, after even a single exposure. We demonstrate that full thickness canine chondral and synovial samples exposed to various local anesthetics and corticosteroids exhibit decreased loss of cell viability compared with prior in vitro studies using monolayer culture, due to the protective effects of intact extracellular matrix and cell heterogeneity.

METHODS

Full-thickness cartilage and synovial explants were obtained from canine cadavers and exposed in culture media to the following for 24 hours: 1% lidocaine, 0.5% lidocaine, 0.25% bupivacaine, 0.125% bupvacaine, 0.0625% bupivacaine, betamethasone acetate, methylprednisolone acetate, triamcinolone acetonide, or culture media only (control). Cell viability was determined on days 1 and 7 of culture using a microscopic live-dead and alamar blue metabolic assays.

RESULTS

Complete loss of chondrocyte and synoviocyte viability was noted in the 1% and 0.5% lidocaine group, 0.25% and 0.125% bupivacaine group, betamethasone group, and methylprednisolone groups after 1 and 7 days of culture. Treatment with 0.0625% bupivacaine and triamcinolone demonstrated no decrease in cell viability or metabolism when compared to negative control.

CONCLUSIONS

In this canine explant model, 1% and 0.5% lidocaine, 0.25% and 0.125% bupivacaine, betamethasone acetate, and methylpresdnisolone acetate were severely chondrotoxic and synoviotoxic after a single exposure, despite intact extracellular matrix. In contrast, chondrocytes and synoviocytes exposed to 0.0625% bupivacaine and triamcinolone remained viable after treatment. Further in vivo study is needed before definitive recommendations can be made.

[Osteoarthritis: what internists should know]

Osteoarthritis is the most frequent joint disorder and substantially affects patient quality of life. As an age-related disease it leads to an increasing financial burden for the healthcare system due to the current demographic changes. Osteoarthritis affects every single tissue in the joint. The identification of the source of disease symptoms is the key to a successful management. Therapeutic approaches include non-pharmacological and pharmacological treatment. Surgery is the therapeutic end stage (e.g. total joint replacement, high tibial osteotomy and arthrodesis). This overview focuses on the pharmacological treatment whereas the clinical manifestations and non-pharmacological approaches are only briefly dealt with.

Effect of intra-articular local anesthesia on articular cartilage in the knee

PURPOSE

To evaluate the hypothetical toxic effect of local anesthetics on the articular cartilage using patient data from autologous chondrocyte cultivation with different anesthesia types used for arthroscopic cartilage biopsy specimen procurement.

METHODS

A retrospective analysis of patient data from the national autologous chondrocyte implantation registry and the corresponding hospital records was approved by the National Medical Ethics Committee. Articular cartilage biopsy specimens from the knees of 49 consecutive patients assigned for autologous chondrocyte implantation (aged 14 to 44 years) were procured from the non-weight-bearing articular surface during arthroscopy under general anesthesia (12 patients), spinal anesthesia (18 patients), or local anesthesia (intra-articular injection of 15 to 20 mL of 2% lidocaine hydrochloride) (19 patients). All the biopsy specimens were further manipulated following the same chondrocyte cultivation protocol. General patient data and surgery-related parameters, together with chondrocyte viability, population doublings, and chondrocyte morphology in biopsy specimens and primary cell cultures, were analyzed and compared across different types of anesthesia.

RESULTS

Patients in the general, spinal, and local anesthesia groups showed no statistical differences in age (27 years, 29 years, and 32 years, respectively), duration of surgery (36 minutes, 37 minutes, and 39 minutes, respectively), weight of biopsy specimens (110 mg, 178 mg, and 130 mg, respectively), cell viability in cartilage biopsy specimens (67%, 69%, and 78%, respectively) or primary cultures (95%, 95%, and 95%, respectively), and population doublings (5.2, 5.2, and 5.2, respectively). Similar chondrocyte morphology in primary cell cultures was observed among the 3 groups.

CONCLUSIONS

This retrospective study showed that a single intra-articular injection of lidocaine hydrochloride used for knee arthroscopy did not influence the viability, morphology, and cultivation potential of chondrocytes in articular cartilage biopsy specimens assigned for autologous chondrocyte implantation.

LEVEL OF EVIDENCE

Level IV, retrospective comparative study.

[Pharmacological therapy of arthrosis]

The pharmacological management of osteoarthritis includes pure analgesia, anti-inflammatory drugs and substances supporting tissue maintenance in osteoarthritic joints. The decision for the treatment modality is made depending on the affected joint, the stage of the disease, the extent and frequency of inflammatory flares and the patient risk profile. This article gives an overview of the current treatment modalities including the advantages and disadvantages.