Inhibition of chondrocyte and synovial cell death after exposure to commonly used anesthetics: chondrocyte apoptosis after anesthetics

Effects of Premixing Betamethasone and Lidocaine on Chondrocyte Inflammation in an In Vitro Model

BACKGROUND

It is common practice for hand surgeons to premix corticosteroids with a local anesthetic and store the mixture in pre-loaded syringes for rapid use during clinic. However, any possible loss of efficacy with this practice has never been studied. The purpose of this study, therefore, is to determine whether premixing betamethasone sodium phosphate/betamethasone acetate (BSP) and lidocaine (L) at different time intervals from injection has diminishing anti-inflammatory effects on chondrocytes in vitro.

METHODS

Human articular chondrocytes were partitioned into six groups: two controls and four experimental conditions. The negative control had growth media only. The positive control had growth media and inflammatory cytokines (interleukin-1β and oncostatin M). Experimental conditions were additionally treated with BSP alone or BSP mixed with lidocaine (BSP + L) at the time of treatment (0 hours), or at 4 or 24 hours prior. Relative expressions of inflammatory genes were measured.

RESULTS

Relative to the positive control, chondrocytes in all experimental conditions decreased expression of TNF-α, MMP-3, and ADAMTS-4. Chondrocytes exposed to BSP only or BSP + L at 4 hours or 24 hours prior to treatment decreased expression of IL-8. Chondrocytes exposed to BSP only or BSP + L at 0 hours or 4 hours prior to treatment decreased expression of MMP-1. There were no significant differences in expression of IL-6 or MMP-13.

CONCLUSIONS

Treatment with BSP + L prepared in pre-loaded syringes at varying time intervals up to 24 hours prior to injection does not significantly impact the ability of the mixture to reduce expression of certain key inflammatory mediators in vitro.

Intra-articular administration of adrenaline plus an irrigation pump system for visibility during the arthroscopic reconstruction of multiple knee ligaments without a tourniquet

Objective

Multiple ligament knee injuries (MLKIs) are rare but severe systemic trauma. Single surgery in the acute setting is preferred, although with an extended operation time. To avoid the complications associated with a tourniquet, we herein describe a method for visibility without a tourniquet: intra-articular administration of adrenaline plus an irrigation pump system.

Study design

This is a cohort study with a level of evidence of 3.

Methods

From April 2020 to February 2022, 19 patients with MLKIs were reviewed retrospectively. All patients got intra-articular administration of adrenaline plus an irrigation pump system for visibility without a tourniquet. The following parameters were assessed: visibility, range of motion, knee stability, visual analog scale (VAS) score, range of motion (ROM), Lysholm score, Tegner activity level, and International Knee Documentation Committee Subjective Knee Form (IKDC).

Results

All patients were followed up for at least 6 months. At the latest follow-up, the mean VAS score, ROM, Lysholm score, and IKDC were 1.79 ± 0.86, 121.21 ± 10.96, 88.16 ± 5.21, and 88.53 ± 5.06, respectively. The average Tegner activity level decreased significantly from preinjury to postoperation (5.16 ± 0.83 vs. 3.11 ± 0.88, P < 0.001). Of the 19 patients, 17 (89.47%) had good knee function, while only two patients (10.53%) had asymptomatic knees with positive Lachman tests. A total of 17 patients (89.47%) had good or excellent visualization during arthroscopy. Of the 19 patients, three (15.79%) required an increased fluid pressure to achieve a clear operative view. Two patients converted to tourniquet inflation due to persistent intra-articular bleeding after using shavers.

Conclusions

The intra-articular administration of adrenaline plus an irrigation pump system is recommended as an alternative to a tourniquet to achieve a good visual field. Further evidence-based work with a larger sample is needed.

Effects of local anesthetics and contrast agents on musculoskeletal regenerative medicine procedures

In regenerative medicine, cells, tissues and organs are often replaced, engineered or regrown in order to restore their function after they have been damaged or lost. Local anesthetics, corticosteroids and contrast agents are commonly employed for both diagnostic and therapeutic objectives in interventional pain and musculoskeletal treatments for regenerative medicine. There is growing evidence that routine injectables promote catabolism and disease processes. Thus, understanding the effects of these compounds on regenerative medicine injectates and target tissues such as tenocytes, chondrocytes, nucleus pulposus and ligamentous tissue is critical. This review includes the current research on the effects of local anesthetics and contrast agents, as well as their use and recommendations in regenerative medicine operations.

Combination of Lidocaine and IL-1Ra Is Effective at Reducing Degradation of Porcine Cartilage Explants

BACKGROUND

Posttraumatic inflammation after joint injury, ranging from sprains to articular fracture, contributes to the development of arthritis, and the administration of interleukin 1 (IL-1) receptor antagonist (IL-1Ra) is a potential intervention to mitigate this response. Although IL-1Ra mitigates cartilage degenerative changes induced by IL-1, lidocaine is used for local pain management in acute joint injury. Intra-articular delivery of both drugs in combination would be a novel and possibly disease-modifying treatment. However, it is not known whether the interaction with lidocaine at clinical concentrations (1%) would alter the efficacy of IL-1Ra to protect cartilage from the catabolic effects of IL-1.

HYPOTHESIS

Treatment of articular cartilage with IL-1Ra in combination with a clinically relevant concentration of lidocaine (1%) will inhibit the catabolic effects of IL-1α in a manner similar to treatment with IL-1Ra alone.

STUDY DESIGN

Controlled laboratory study.

METHODS

Fresh porcine cartilage explants were harvested, challenged with IL-1α, and incubated for 72 hours with IL-1Ra or a combination of IL-1Ra and lidocaine. The primary outcome was total sulfated glycosaminoglycan (sGAG) release. Additional experiments assessed the effect of storage temperature and premixing of IL-1Ra and lidocaine on sGAG release. All explants were histologically assessed for cartilage degradation using a modified Mankin grading scale.

RESULTS

The combination of IL-1Ra and lidocaine, premixed at various time points and stored at room temperature or 4°C, was as effective as IL-1Ra alone at inhibiting IL-1α-mediated sGAG release. Mankin histopathology scores supported these findings.

CONCLUSION

Our hypothesis was supported, and results indicated that the combination of IL-1Ra and lidocaine was as efficacious as IL-1Ra treatment alone in acutely mitigating biological cartilage injury due to IL-1α in an explant model.

CLINICAL SIGNIFICANCE

The combination of IL-1Ra and lidocaine is stable when reagents are stored in advance of administration at varying temperatures, providing clinically relevant information about storage of medications. The ability to premix and store this drug combination for intra-articular delivery may provide a novel treatment after joint injury to provide pain relief and block inflammation-induced catabolism of joint tissues.

Osteoarthritis: Novel Molecular Mechanisms Increase Our Understanding of the Disease Pathology

Although osteoarthritis (OA) is the most common musculoskeletal condition that causes significant health and social problems worldwide, its exact etiology is still unclear. With an aging and increasingly obese population, OA is becoming even more prevalent than in previous decades. Up to 35% of the world’s population over 60 years of age suffers from symptomatic (painful, disabling) OA. The disease poses a tremendous economic burden on the health-care system and society for diagnosis, treatment, sick leave, rehabilitation, and early retirement. Most patients also experience sleep disturbances, reduced capability for exercising, lifting, and walking and are less capable of working, and maintaining an independent lifestyle. For patients, the major problem is disability, resulting from joint tissue destruction and pain. So far, there is no therapy available that effectively arrests structural deterioration of cartilage and bone or is able to successfully reverse any of the existing structural defects. Here, we elucidate novel concepts and hypotheses regarding disease progression and pathology, which are relevant for understanding underlying the molecular mechanisms as a prerequisite for future therapeutic approaches. Emphasis is placed on topographical modeling of the disease, the role of proteases and cytokines in OA, and the impact of the peripheral nervous system and its neuropeptides.

Local anesthesia combined with intra-articular ropivacaine can provide satisfactory pain control in ankle arthroscopic surgery: A retrospective cohort study

BACKGROUND

Local anesthesia (LA) is widely used in knee arthroscopic surgery but not in ankle arthroscopy.

OBJECTIVE

To understand the effectiveness and safety of LA combined with ropivacaine in pain control for ankle arthroscopy.

STUDY DESIGN

Retrospective cohort.

METHODS

We retrospectively collected data for patients who underwent ankle arthroscopy from April 2012 to April 2017. Patients were grouped by anesthesia method: LA, LA with ropivacaine (LA+R), spinal anesthesia (SA), and SA with ropivacaine (SA+R). Intra- and postoperative visual analog scale (VAS) scores, complications, doses of supplemental pain medication, hospitalization cost and duration, and satisfaction with pain control during hospitalization were analyzed.

RESULTS

The study included 276 patients (LA: 93; LA+R: 124; SA: 31; SA+R: 28). The LA and LA+R groups had significantly higher intraoperative VAS scores (LA vs. SA, p = 0.001; LA vs. SA+R, p = 0.002; LA+R vs. SA, p = 0.00; LA+R vs. SA+R, p = 0.00), but fewer complications, than the SA and SA+R groups. The LA+R and SA+R groups had significantly better outcomes for postoperative pain control (LA vs. LA+R, p = 0.01; LA vs. SA+R, p = 0.01; SA vs. SA+R, p = 0.01; SA vs. LA+R, p = 0.03) and required less supplemental pain medication. Hospitalization cost was lower and duration shorter in the LA and LA+R groups than in the SA and SA+R groups. There was no significant difference in satisfaction among the four groups.

LIMITATIONS

This was a single-center retrospective and relatively short-term study.

CONCLUSIONS

LA+R which could be safely applied in ankle arthroscopy provided satisfactory pain control, reduced postoperative pain intensity, fewer complications, shorter hospital stay, and good cost-effectiveness. It can be safely applied in ankle arthroscopy for the specific patients with ankle osteoarthritis.

A Treatment-Based Algorithm for the Management of Type-II SLAP Tears

Background:

The management of Type-II superior labral tears (SLAP) of the shoulder remains a controversial topic. Treatment ranges from non-operative management to surgical management including SLAP repair, biceps tenotomy, and biceps tenodesis. An optimal treatment algorithm has yet to reach universal acceptance.

Objective:

The goal of this paper was to provide a treatment algorithm for the management of Type-II SLAP tears based on current literature and expert opinion.

Method:

Current literature was reviewed and expert opinion was reported to develop a comprehensive treatment protocol for patients based on age, activity level, and pathology.

Results:

Operative management of type-II SLAP tears yields good to excellent outcomes when proper indications are followed. Biceps tenodesis may produce more reliable pain relief and functional improvement when compared to primary SLAP repair in patients over the age of 40.

Conclusion:

When non-operative management of Type-II SLAP tears fails, operative management yields good to excellent outcomes in most patients. Primary SLAP repair should be performed in patients under the age of 40 with no evidence of proximal biceps pathology, while biceps tenodesis can provide consistent pain relief and return to activity in patients over the age of 40 or with significant proximal biceps pathology. Tenotomy should be reserved for elderly or low demand individuals.

ROS-mediated lysosomal membrane permeabilization is involved in bupivacaine-induced death of rabbit intervertebral disc cells

Bupivacaine is frequently administered for diagnosing and controlling spine-related pain in interventional spine procedures. However, the potential cytotoxic effects of bupivacaine on intervertebral disc (IVD) cells and the underlying molecular mechanisms have not yet been fully established. Here, we showed that bupivacaine decreased the viability of rabbit IVD cells in a dose- and time-dependent manner. Moreover, the short-term cytotoxicity of bupivacaine in IVD cells was primarily due to cell necrosis, as assessed by Annexin V-propidium iodide staining and live/dead cell staining. Necrosis was verified by observations of swollen organelles, plasma membrane rupture, and cellular lysis under transmission electronic microscopy. Interestingly, our data indicated that bupivacaine-induced primary necrosis might involve the necroptosis pathway. The key finding of this study was that bupivacaine was able to induce lysosomal membrane permeabilization (LMP) with the release of cathepsins into the cytosol, as evidenced by LysoTracker Red staining, acridine orange staining, and cathepsin D immunofluorescence staining. Consistently, inhibitors of lysosomal cathepsins, CA074-Me and pepstatin A, significantly reduced bupivacaine-induced cell death. Finally, we found that bupivacaine resulted in an increase in intracellular reactive oxygen species (ROS) and that inhibition of ROS by N-acetyl-L-cysteine effectively blocked bupivacaine-induced LMP and cell death. In summary, the results of this in vitro study reveal a novel mechanism underlying bupivacaine-induced cell death involving ROS-mediated LMP. Our findings establish a basis for the further investigation of bupivacaine cytotoxicity in an in vivo system.

•

Bupivacaine decreases IVD cell viability in a dose- and time-dependent manner.

•

The short-term cytotoxicity of bupivacaine is primarily due to cell necrosis.

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LMP is involved in bupivacaine-induced death of IVD cells.

•

ROS is an important mediator in bupivacaine-induced LMP and cell death.

Comparison of Cytotoxic Effects of Intra-Articular Use of Tranexamic Acid versus Epinephrine on Rat Cartilage

Background

Adequate visualization is known to be essential to perform arthroscopic procedures effectively and efficiently. We hypothesized that tranexamic acid may be considered as an alternative agent to reduce intra-articular bleeding during arthroscopic procedures, after comparing its potential chondrotoxicity with that of epinephrine.

Material/Methods

Seventy-two rats were randomized into 3 groups with 24 rats each. The injections were performed in the right knees, as follows: Group 1: 0.25 mL of tranexamic acid solution, Group 2: 0.25 mL of epinephrine solution, and Group 3: 0.25 mL of 0.9% saline, serving as control. One week after the injections, the animals were euthanized. Samples were evaluated histologically based on the Osteoarthritis Research Society International (OARSI) Histopathology Grading and Staging System and the “live/dead” staining technique to determine chondrocyte viability.

Results

Comparison of epinephrine and tranexamic acid revealed significantly higher OARSI scores in the epinephrine group (epinephrine: 3.42±1.31, TA: 0.92±0.90; P<0.001). The most significant difference between the 2 groups was in the number of joints diagnosed with OARSI grade III. The percentage of viability was significantly higher in the tranexamic acid group when compared with the epinephrine group (tranexamic acid: 79.74±3.343; epinephrine: 63.81±1.914; P<0.05).

Conclusions

Based on the histologic parameters and chondrocyte viability, tranexamic acid is less cytotoxic than epinephrine in rat chondrocytes at the doses typically used in irrigation fluid, and may be a good alternative to epinephrine in arthroscopic surgery.

Ropivacaine alters the mechanical properties of hamstring tendons: In vitro controlled mechanical testing of tendons from living donors

OBJECTIVE

Intraarticular or periarticular injection of ropivacaine (RI) is an element of current knee surgery practices. The goal of this study was to determine the effects of RI on the mechanical properties of hamstring tendons. We hypothesized that RI would have a detrimental effect on the mechanical properties of periarticular soft tissues METHODS: A tensile test to failure was performed on 120 hamstring tendon segments harvested during ACL reconstruction surgery in 120 patients. Two sets of tensile tests were done. The first evaluated the effect of RI itself on the mechanical properties of tendons: 30 samples were soaked for 1hour in a 2% RI solution and compared to 30 samples soaked in a saline solution (control group). The second evaluated the effect of RI concentration on the mechanical properties of hamstring tendons: 30 samples were soaked for 1hour in a 2% RI solution and 30 samples were soaked in a 7.5% RI solution.

RESULTS

In the first test, 29 samples from each group were analyzed as two samples (one in each group) failed at the grip interface. The specimens exposed to 2% RI had lower ultimate tensile strength (Δ=4.4MPa, P=0.001), strain energy (Δ=13MPa, P=0.001) and Young's modulus (Δ=1.6MPa, P=0.02) than the specimens in the control group. There was no significant difference in the strain at failure between groups (Δ=5%, P=0.3). In the second test, one specimen from the 7.5% RI group failed during the preloading and was excluded. There was no significant difference in terms of the load at failure and ultimate tensile stress (Δ=0.45MPa, P=0.6) and strain energy (Δ=0.49MPa, P=0.49) between the two groups. There were significant differences in terms of elongation at failure (Δ=28%, P=0.0003) and Young's modulus (Δ=2.6MPa, P=0.005), with the specimens exposed to 7.5% RI undergoing greater deformation and having a lower Young's modulus.

DISCUSSION

While local RI injections are widely performed in clinical practice, the results of this in vitro study point to short-term alterations of the mechanical properties of hamstring tendons. If these results hold in vivo, this could lead to weakness of the soft tissues exposed to this product, particularly the tendons and ligaments around the injection area.

LEVEL OF EVIDENCE

Experimental study. Level 1.

N-acetyl cysteine protects cells from chondrocyte death induced by local anesthetics

Local anesthetics (LA) are among the drugs most frequently used for musculoskeletal problems, in procedures ranging from diagnosis to postoperative pain control. Chondrocyte toxicity induced by LA is an emerging area of concern. The purpose of this study was to determine whether N-acetyl cysteine (NAC), an antioxidant, will exert cytoprotective effects against chondrocyte death induced by LA. Primary cultured human chondrocytes were used for this study. This study used control, NAC, LA, and NAC-LA groups. Cytotoxicity was induced in the LA subgroups and their paired NAC-LA subgroups through exposure to ropivacaine (0.075%), bupivacaine (0.05%), or lidocaine (0.2%) for 24 h. The NAC-LA subgroups were exposed to 10 mM NAC for 1 h, before LA exposure. These study groups were evaluated for rates of cell viability, apoptosis, necrosis, intracellular ROS production, and caspase-3/7 activity. Cell viability in all LA subgroups was significantly lower than in the control group (p < 0.001). Cell viability in the NAC-LA subgroups was significantly higher than in their paired LA subgroups (p < 0.001). In the LA subgroups, rates of apoptosis and necrosis, intracellular ROS production, and caspase-3/7 activity were significantly higher than in the control group (p ≤ 0.029). In the NAC-LA subgroups, rates of apoptosis and necrosis, intracellular ROS production, and caspase-3/7 activity were significantly lower than in their paired LA subgroups (p ≤ 0.023). These results indicate that N-acetyl cysteine, an antioxidant, has cytoprotective effects against LA-induced toxicity to chondrocytes in vitro. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:297-303, 2017.

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.

Therapeutic Review of Methylprednisolone Acetate Intra-Articular Injection in the Management of Osteoarthritis of the Knee - Part 2: Clinical and Procedural Considerations

The use of an intra-articular methylprednisolone acetate (MPA) injection has been shown to have benefits for symptoms of knee osteoarthritis (OA). However, considerations beyond drug efficacy can influence the appropriateness, clinical effectiveness and potential harm of an injection. A review of research evidence and published literature on clinical and procedural factors influencing the effectiveness and safety of a knee injection has been undertaken. Factors include dose, frequency, contraindications, precautions, drug interactions, side-effects, and procedural and patient-related considerations. An evaluation of evidence indicated that a 40 mg dose provides clinical benefit. No strong predictors of response were evident, with the exception of pain severity. Additional benefit for outcomes from higher doses, local anaesthetic, ultrasound guidance or particular anatomical approaches is yet to be demonstrated. Evidence for dose- and duration-related detrimental effects suggests judicious use and frequency. The evaluation showed that there are a number of contraindications and precautions arising from the drug pharmacology, concurrent medications, comorbidities and adverse events which need consideration and monitoring. There was limited safety evidence concerning anticoagulation. The review found that specialist guidance and limited evidence suggests that injection safety concerning warfarin may be enhanced by ensuring that the international normalized ratio level is within therapeutic range. However, the risk-benefit evaluation concerning non vitamin K antagonist oral anticoagulants remains challenging. Although there is published guidance, a lack of clinical studies, safety evidence and reversibility advocates caution. Overall, the review indicates that injection decisions and procedures need an individualized approach and supporting evidence is limited in many areas. Evaluation and discussion of benefits and risks, peri-procedural and post-injection management, and tailoring to the context and individuals' preferences are important in optimizing the benefits and safety of a knee injection.

Analgesic effect and safety of single-dose intra-articular magnesium after arthroscopic surgery: a systematic review and meta-analysis

To examine the analgesic effect and safety of single-dose intra-articular (IA) magnesium (Mg) after arthroscopic surgery. Pubmed, Embase and Cochrane library were searched through in January 2016. Eight RCTs and eight experimental studies were included. The IA Mg exhibited a significantly lower pain score when compared with placebo (MD, -0.41, 95% CI, -0.78 to -0.05, p = 0.03). There was no significant difference between Mg and bupivacaine in terms of pain relief and the time to first analgesic request. Furthermore, statistically significant differences both in pain score (MD, -0.62, 95% CI, -0.81 to -0.42, p < 0.00001) and time to first analgesic request (MD, 6.25, 95% CI, 5.22 to 7.29, p < 0.00001) were observed between Mg plus bupivacaine and bupivacaine alone. There was no statistically significant difference among the various groups with respect to adverse reactions. Most of the included in vitro studies reported the chondrocyte protective effect of Mg supplementation. There were also two in vivo studies showing the cartilage protective effect of IA Mg. The single-dose IA Mg following arthroscopic surgery was effective in pain relief without increasing adverse reactions, and it could also enhance the analgesic effect of bupivacaine. In addition, Mg seemed to possess the cartilage or chondrocyte protective effect based on experimental studies.

Effects of Multiple Intra-articular Injections of 0.5% Bupivacaine on Normal and Osteoarthritic Joints in Rats

PURPOSE

To determine the in vivo effects of multiple local anesthetic injections of 0.5% bupivacaine on normal and osteoarthritic articular cartilage.

METHODS

Rats with normal knee joints received an intra-articular injection of 0.9% saline solution or 0.5% bupivacaine in their right knees joint once a week for 5 consecutive weeks, starting 4 weeks after the beginning of the experiment. Rats were humanely killed at 8, 16, and 24 weeks. In a parallel experiment, rats underwent anterior cruciate ligament transection to induce osteoarthritic changes. These rats were subjected to the same protocol as those with normal knee joints, starting 4 weeks after the procedure. Static weight-bearing tests were performed on both hind limbs to evaluate changes in weight-bearing ability throughout the experiments. Rats were humanely killed at 8 and 16 weeks. Cell viability was assessed with confocal microscopy, using samples from the distal femur. Histologic assessment of osteoarthritis was performed using samples from the tibial plateau based on the Osteoarthritis Research Society International (OARSI) cartilage histopathology assessment system (i.e., OARSI score).

RESULTS

Static weight-bearing tests showed no significant changes after intra-articular injection of saline solution or bupivacaine, and bupivacaine injection did not increase weight bearing compared with saline solution injection, regardless of whether there were osteoarthritic changes. There were also no significant differences in cell viability, cell density, or OARSI scores between the saline solution and bupivacaine groups at each time point, regardless of whether osteoarthritic changes were induced.

CONCLUSIONS

This study suggested that single or intermittent intra-articular bupivacaine injections might not have deleterious effects on either osteoarthritic or normal joints.

CLINICAL RELEVANCE

There is no strong evidence that intra-articular bupivacaine injection induces degenerative changes in articular cartilage. Therefore, these results may apply to normal and osteoarthritic joints.

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.

Hyaluronan suppresses lidocaine-induced apoptosis of human chondrocytes in vitro by inhibiting the p53-dependent mitochondrial apoptotic pathway

AIM

Intra-articular injection of local anesthetics (LAs) is a common procedure for therapeutic purposes. However, LAs have been found toxic to articular cartilage, and hyaluronan may attenuate this toxicity. In this study we investigated whether hyaluronan attenuated lidocaine-induced chondrotoxicity, and if so, to elucidate the underlying mechanisms.

METHODS

Human chondrocyte cell line SW1353 and newly isolated murine chondrocytes were incubated in culture medium containing hyaluronan and/or lidocaine for 72 h. Cell viability was evaluated using MTT assay. Cell apoptosis was detected with DAPI staining, caspase 3/7 activity assay and flow cytometry. Cell cycle distributions, ROS levels and mitochondrial membrane potential (ΔΨm) were determined using flow cytometry. The expression of p53 and p53-regulated gene products was measured with Western blotting.

RESULTS

Lidocaine (0.005%-0.03%) dose-dependently decreased the viability of SW1353 cells. This local anesthetic (0.015%, 0.025%) induced apoptosis, G2/M phase arrest and loss of ΔΨm, and markedly increased ROS production in SW1353 cells. Hyaluronan (50-800 μg/mL) alone did not affect the cell viability, but co-treatment with hyaluronan (200 μg/mL) significantly attenuated lidocaine-induced apoptosis and other abnormalities in SW1353 cells. Furthermore, co-treatment with lidocaine and hyaluronan significantly decreased the levels of p53 and its transcription targets Bax and p21 in SW1353 cells, although treatment with lidocaine alone did not significantly change these proteins. Similar results were obtained in ex vivo cultured murine chondrocytes.

CONCLUSION

Hyaluronan suppresses lidocaine-induced apoptosis of human chondrocytes in vitro through inhibiting the p53-dependent mitochondrial apoptotic pathway.

Single-dose intra-articular ropivacaine after arthroscopic knee surgery decreases post-operative pain without increasing side effects: a systematic review and meta-analysis

PURPOSE

The purpose of this study was to appraise the efficacy and safety of single-dose intra-articular ropivacaine administered for pain relief after arthroscopic knee surgery.

METHODS

PubMed, Embase, and Cochrane Library databases were searched in October 2014 to identify randomized controlled trials of single-dose intra-articular ropivacaine for post-operative pain relief. Post-operative pain intensity, the amount of rescue analgesia required, and side effects including local anaesthetic toxicity were assessed. The relative risk (RR), the weighted mean difference (WMD), and their corresponding 95 % confidence intervals (CIs) were calculated.

RESULTS

Eight randomized controlled trials were included in the analysis. Statistically significant differences in the visual analogue scale for pain intensity value were observed during the immediate post-operative period (WMD -10.35, 95 % CI -17.12 to -3.59, p = 0.003) and the early post-operative period (WMD -11.90, 95 % CI -18.12 to -5.69, p = 0.0002), but not during the late post-operative period (WMD -2.89, 95 % CI -7.46 to 1.68, n.s.). There was no significant difference in the amount of rescue analgesia required (RR 0.76, 95 % CI 0.52-1.11, n.s.). Only two trials reported the incidence of drug-related side effects (including nausea and vomiting): the incidence in the ropivacaine groups was no higher than that in the control groups. Only one trial assessed local anaesthetic toxicity as an outcome, but it was not detected.

CONCLUSIONS

Single-dose intra-articular ropivacaine administered at the end of arthroscopic knee surgery provides effective pain relief in the immediate and early post-operative periods without increasing short-term side effects.

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.

Steroids, lidocain and ioxaglic acid modify the viscosity of hyaluronic acid: in vitro study and clinical implications

Background

Viscosupplementaion by intra-articular injection of hyaluronic acid (HA) is a therapeutic modality for treating osteoarthritis of the knee, of the hip and less frequently of other joints. During viscosupplementation, it is usual to inject other drugs, without knowing whether this association may have a deleterious effect thereon. The rheological properties of a viscosupplement are highly dependent on the product [molecular weight × concentration] of HA. Therefore, any reduction of its viscoelastic properties is related either to a decrease of its concentration or/and of its molecular weight. The presence of other molecules can create favorable or unfavorable molecular interactions with HA. The objective of the study was to investigate the effect of products, that are commonly associated with HA (corticosteroids, lidocain, iodinated contrast media), on the rheological behavior of HA, then to try drawing practical conclusions.

Methods

The rheological behavior of both a linear and a cross-linked HA, was studied before and after mixing with different volumes (ratio 1:0.5–1:4) of the following compounds: phosphate buffered saline (PBS, as a control), cortivazol, triamcinolone hexacetonide, lidocain chlorhydrate and meglumine ioxaglate. The flow curve of the different samples was obtained using a measuring method based on a constant shear rate.

Results

Whatever the dilution and the added molecule were, viscosity of the cross-linked viscosupplement remained much higher than that of the linear one. Addition of PBS at a ratio 1:1 caused a dramatic decrease (up to 97.5 %) of HA viscosity. Cortivazol and lidocain had a similar effect than PBS on linear HA. Both were much deleterious on cross-linked HA viscosity. Among corticosteroids, triamcinolone decreased much less HA viscosity than cortivazol. The effect of meglumine ioxaglate was dose-dependent. Up to a ratio 1:1 viscosity of the linear HA remained above the dilution effect. On the cross-linked HA, the deleterious effect of the contrast agent was evident as soon as a ratio 1:1 and became very marked at 1:2.

Conclusion

HA viscosity varies widely in presence of other molecules. These changes are due to both dilution and molecular interactions. This study suggests that addition of other molecules with HA can lead to a major decrease of its viscosity. However, provided to respect a maximum ratio of 1:1, the contrast medium and triamcinolone seem to have no major deleterious effect on the viscosity level, especially on crosslinked HA. The study also suggests a deleterious effect of lidocain on the cross-linked HA. These in vitro data suggest that drugs associations must be avoided when they are not essential. However, clinical trials are needed to determine whether these rheological changes may have a significant impact on the clinical outcome.

Comparative effects of vitamin C on the effects of local anesthetics ropivacaine, bupivacaine, and lidocaine on human chondrocytes

BACKGROUND

Intra-articular injections of local anesthetics are commonly used to enhance post-operative analgesia following orthopedic surgery as arthroscopic surgeries. Nevertheless, recent reports of severe complications due to the use of intra-articular local anesthetic have raised concerns.

OBJECTIVES

The study aims to assess use of vitamin C in reducing adverse effects of the most commonly employed anesthetics - ropivacaine, bupivacaine and lidocaine - on human chondrocytes.

METHODS

The chondrocyte viability following exposure to 0.5% bupivacaine or 0.75% ropivacaine or 1.0% lidocaine and/or vitamin C at doses 125, 250 and 500 μM was determined by LIVE/DEAD assay and annexin V staining. Expression levels of caspases 3 and 9 were assessed using antibodies by Western blotting. Flow cytometry was performed to analyze the generation of reactive oxygen species.

RESULTS

On exposure to the local anesthetics, chondrotoxicity was found in the order ropivacaine<bupivacaine<lidocaine. Vitamin C effectively improved the reduced chondrocyte viability and decreased the raised apoptosis levels following exposure to anesthesia. At higher doses, vitamin C was found efficient in reducing the generation of reactive oxygen species and as well down-regulate the expressions of caspases 3 and 9.

CONCLUSIONS

Vitamin C was observed to effectively protect chondrocytes against the toxic insult of local anesthetics ropivacaine, bupivacaine and lidocaine.

Effect of highly purified capsaicin on articular cartilage and rotator cuff tendon healing: An in vivo rabbit study

Highly purified capsaicin has emerged as a promising injectable compound capable of providing sustained pain relief following a single localized treatment during orthopedic surgical procedures. To further assess its reliability for clinical use, the potential effect of highly purified capsaicin on articular cartilage metabolism as well as tendon structure and function warrants clarification. In the current study, rabbits received unilateral supraspinatus transection and repair with a single 1 ml injection of capsaicin (R+C), PEG-only placebo (R+P), or saline (R+S) into the glenohumeral joint (GHJ). An additional group received 1 ml capsaicin onto an intact rotator cuff (I+C). At 18 weeks post-op, cartilage proteoglycan (PG) synthesis and content as well as cell viability were similar (p>0.05) across treatment groups. Biomechanical testing revealed no differences (p>0.05) among tendon repair treatment groups. Similarly, histologic features of both cartilage and repaired tendons showed minimal differences across groups. Hence, in this rabbit model, a single injection of highly purified capsaicin into the GHJ does not induce a deleterious response with regard to cartilage matrix metabolism and cell viability, or rotator cuff healing. These data provide further evidence supporting the use of injectable, highly purified capsaicin as a safe alternative for management of postoperative pain following GHJ surgery.

Local anesthetic cytotoxicity on human mesenchymal stem cells during chondrogenic differentiation

PURPOSE

This study was to investigate the cytotoxic potency of local anesthetics on human mesenchymal stem cells during chondrogenesis.

METHODS

Aggregates were created from density-gradient centrifugation-separated bone marrow-derived mesenchymal stem cells. After 7, 14, and 21 days, aggregates were analyzed histologically and immunohistochemically and exposed to equipotent concentrations of bupivacaine, ropivacaine, and mepivacaine for 1 h. Cell viability, apoptosis, and necrosis were determined using live-dead and caspase staining. Additionally, following a 1-h exposure on day 7, aggregates were cultured under chondrogenic conditions until day 21 to assess the effects of local anesthetics on differentiation potency of mesenchymal stem cells.

RESULTS

In the course of chondrogenesis, mesenchymal stem cells were embedded in varying amount and structure of cartilage-specific extracellular matrix. Contents of sulfated glycosaminoglycan, type I and II collagen increased from day 7 to day 21. Compared to control, death rates of mesenchymal stem cells were significantly elevated 1 day after treatment at 7 and 14 days. Four days after exposure, death rates were 13-15 % at 7 and 11-17 % at 14 days. Mesenchymal stem cell viability in aggregates at 21 days was unchanged to controls. The width of the superficial aggregate zone containing stem cell necrosis decreased with elongated differentiation time. Apoptosis rates were elevated in the edge regions of aggregates, reaching maximum values 4 days after treatment. Local anesthetic exposure on day 7 reduced Collagen II, but not DNA contents in aggregates at 21 days. Bupivacaine, ropivacaine, and mepivacaine did not differ in mesenchymal stem cell cytotoxicity in aggregates.

CONCLUSION

Local anesthetic exposure results in cytotoxicity of mesenchymal stem cells undergoing chondrogenesis, especially in superficial layers. Therefore, induced cell damage should be avoided during chondrogenesis of mesenchymal stem cells, particularly early after cartilage repair.