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

Interventional Radiology for Rheumatic Diseases

Imaging plays a key role in the management of rheumatological pathologies, also as guidance for diagnostic and therapeutic interventional procedures, as it can provide better accuracy and safety compared to palpation-guided interventions. Inflammatory and degenerative conditions nonresponsive to systemic treatment may benefit from intra-articular and periarticular administration of drugs, with therapeutic and symptomatic actions or providing a bridge for surgery. Desired effects include reduction of inflammation and pain and improvement of physical function of patients. Training and knowledge of indications, appropriate procedures, contraindications, and side effects are necessary to obtain maximum accuracy and safety in performing interventional procedures.

Ultrasound versus palpation-guided corticosteroid injection for de Quervain disease: A randomized controlled trial

INTRODUCTION

Corticosteroid injection effectively treats de Quervain disease, and due to the high prevalence of the intracompartmental septum in the first extensor compartment, ultrasound guidance improves injection accuracy.

OBJECTIVE

To compare the effectiveness, adverse events, and the recurrence rate between ultrasound-guided and palpation-guided injection in patients with de Quervain disease.

DESIGN

Prospective, single-blind, randomized controlled trial.

SETTING

Rehabilitation department of a private teaching hospital.

PARTICIPANTS

We enrolled 49 patients, ≥20 years of age, clinically diagnosed with de Quervain disease based on their medical history and physical examination.

INTERVENTIONS

Patients were randomized into two groups: ultrasound-guided and palpation-guided injection. Both groups received a mixture of 10 mg triamcinolone acetonide (10 mg/1 mL) and 0.3 mL 1% lidocaine.

MAIN OUTCOME MEASURES

The primary outcome measure was the Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) score at 1 week. The secondary outcome measures were visual analog scale for pain (pain VAS) score, patient satisfaction, and adverse events or complications from the interventions at 1 week, 3 months, and 6 months.

RESULTS

Both groups showed improvement over time in QuickDASH scores and pain VAS (p < .001); however, no statistically significant differences were noted between the groups for either QuickDASH scores (p = .22) or pain VAS (p = .30). In addition, no statistically significant differences were found between the groups in terms of patient satisfaction (p = .76) and adverse events (p = .47, .33, .58) at the 1-week, 3-month, and 6-month follow-ups.

CONCLUSIONS

Both ultrasound-guided and palpation-guided injections effectively treated de Quervain disease. During a 6-month follow-up, there were no statistically significant differences between the groups in pain relief, upper limb function, or patient satisfaction. However, the palpation-guided group showed a tendency for more recurrence and skin side effects.

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.

Cytoprotective Effect of Growth Factors Derived From Platelets on Corticosteroid-Treated Primary Anterior Cruciate Ligament-Derived Stromal Cells and Chondrocytes

Background The use of corticosteroids, such as methylprednisolone, for pain management is a common clinical practice. However, it is well known that corticosteroids induce toxicity in anterior cruciate ligament (ACL)-derived stromal cells and chondrocytes. Growth factors from platelets have anti-inflammatory effects that can potentially limit the cytotoxic effects of corticosteroids. In this study, we explored the role of growth factors obtained from the OssinextTM kit (commercially available Wockhardt growth factor concentrate (GFC) kit) in recovering methylprednisolone-induced cell damage. Methodology Primary ACL-derived stromal cells and chondrocytes were isolated from human ligament tissue and articular cartilage, respectively, and characterized by immunophenotyping, gene expression analysis, and immunostaining. GFC obtained from OssinextTM kit was used for the experiments. The ACL-derived stromal cells and chondrocytes were treated with methylprednisolone, alone or in combination with GFC. Cell viability was measured by the neutral red uptake assay. Changes in cell morphology and collagen pattern were observed microscopically by H&E staining and immunostaining, respectively. Cell proliferation was assessed by cell migration assay, and the cell ultra-structure was analyzed using transmission electron microscopy. Results Methylprednisolone was found to induce cytotoxicity, altered cell morphology, reduced cell proliferation, and organelle damage in both ACL-derived stromal cells and chondrocytes. GFC obtained from the OssinextTM kit was able to restore cell viability and reverse the cell structure damages induced by methylprednisolone. GFC was found to recover and protect the cells, both when used in combination with steroids and when used after the steroid treatment. Conclusions The results indicate that GFC may be clinically beneficial when used in combination with steroids to mitigate their adverse effects.

Lidocaine inhibits migration of tenocytes by downregulating focal adhesion kinase and paxillin phosphorylation

Lidocaine is the most frequently applied local infiltration anesthetic agent for treating tendinopathies. However, studies have discovered lidocaine to negatively affect tendon healing. In the current study, the molecular mechanisms and effects of lidocaine on tenocyte migration were evaluated. We treated tenocytes intrinsic to the Achilles tendons of Sprague-Dawley rats with lidocaine. The migration ability of cells was analyzed using electric cell-substrate impedance sensing (ECIS) and scratch wound assay. We then used a microscope to evaluate the cell spread. We assessed filamentous actin (F-actin) cytoskeleton formation through immunofluorescence staining. In addition, we used Western blot analysis to analyze the expression of phospho-focal adhesion kinase (FAK), FAK, phospho-paxillin, paxillin, and F-actin. We discovered that lidocaine had an inhibitory effect on the migration of tenocytes in the scratch wound assay and on the ECIS chip. Lidocaine treatment suppressed cell spreading and changed the cell morphology and F-actin distribution. Lidocaine reduced F-actin formation in the tenocyte during cell spreading; furthermore, it inhibited phospho-FAK, F-actin, and phospho-paxillin expression in the tenocytes. Our study revealed that lidocaine inhibits the spread and migration of tenocytes. The molecular mechanism potentially underlying this effect is downregulation of F-actin, phospho-FAK, and phospho-paxillin expression when cells are treated with lidocaine.

Cytotoxicity of Local Anesthetics on Bone, Joint, and Muscle Tissues: A Narrative Review of the Current Literature

Background

Local anesthetics are commonly used in surgical procedures to control pain in patients. Whilst the cardiotoxicity and neurotoxicity of local anesthetics have received much attention, the cytotoxicity they exert against bone, joint, and muscle tissues has yet to be well recognized.

Objective

This review aimed to raise awareness regarding how local anesthetics may cause tissue damage and provide a deeper understanding of the mechanisms of local anesthetic-induced cytotoxicity. We summarized the latest progress on the cytotoxicity of local anesthetics and the underlying mechanisms and discussed potential strategies to reduce it.

Findings

We found that the toxic effects of local anesthetics on bone, joint, and muscle tissues were time- and concentration-dependent in vitro. Local anesthetics induced apoptosis, necrosis, and autophagy through specific cellular pathways. Altogether, this review indicates that toxicity of local anesthetics may be avoided by rationally selecting the appropriate anesthetic, limiting the total amount, and determining the lowest effective concentration and duration.

Treatment Options for Patellofemoral Arthritis

PURPOSE OF REVIEW

To present a synthesis of recent literature regarding the treatment of patellofemoral arthritis RECENT FINDINGS: Risk factors of PFJ OA include patella malalignment or maltracking, injury to supportive structures including the MPFL, dysfunction of hamstring and quadriceps coordination, lower limb alignment, trochlear dysplasia, patellar trauma, or ACL surgery. Special physical exam maneuvers include patellar grind test, apprehension test, and lateral patellar tilt angle. Radiographs that should be obtained first-line include weight bearing bilateral AP, lateral, and Merchant views. CT and MRI are used to assess trochlear dysplasia, excessive patellar height, and TT-TG distance. Non-operative management options discussed include non-pharmacologic treatment (patient education, self-management, physical therapy, weight loss), ESWT, cold therapy, taping, bracing, and orthotics. Pharmacologic management options discussed include NSAIDs, acetaminophen, oral narcotics, and duloxetine. Injection therapies include glucocorticoids, hyaluronic acid, PRP, and other regenerative therapies (BMAC, adipose, or mesenchymal stem cells). Other treatment options include radiofrequency ablation and botulinum toxin. The algorithm for the surgical treatment of PFJ OA can begin with arthroscopic assessment of the PF articular cartilage to address mechanical symptoms and to evaluate/treat lateral soft tissue with or without overhanging lateral osteophytes. If patients fail to have symptomatic improvement, a TTO can be considered in those patients less than 50 years of age or active patients >50 years old. In patients with severe PFJ OA, refractory to the above treatments, PFA should be considered. While early PFA design and technique were less than encouraging, more recent implant design and surgical technique have demonstrated robust results in the literature. Patellofemoral osteoarthritis is a challenging orthopedic problem to treat, in that it can often affect younger patients, with otherwise well-functioning knees. It is a unique entity compared to TF OA with distinct epidemiology, biomechanics and risk factors and treatment options.

Ex vivo effects of corticosteroids on equine deep digital flexor and navicular fibrocartilage explant cell viability

OBJECTIVE

To investigate the effects of triamcinolone acetonide (TA) and methylprednisolone acetate (MPA) on the viability of resident cells within the fibrocartilage on the dorsal surface of the deep digital flexor tendon (FC-DDFT) and fibrocartilage on the flexor surface of the navicular bone (FC-NB) of horses.

SAMPLE

12 to 14 explants of FC-DDFT and of FC-NB from grossly normal forelimbs of 5 cadavers of horses aged 9 to 15 years without evidence of musculoskeletal disease.

PROCEDURES

Explants were incubated with culture medium (control) or TA-supplemented (0.6 or 6 mg/mL) or MPA-supplemented (0.5 or 5 mg/mL) medium for 6 or 24 hours. Explant metabolic activity and percentage of dead cells were assessed with a resazurin-based assay and live-dead cell staining, respectively, at each time point. Drug effects were assessed relative to findings for the respective control group.

RESULTS

Application of TA (at both concentrations) did not significantly change the cell viability of FC-DDFT explants. For FC-NB explants, TA at 6 mg/mL significantly reduced the metabolic activity and increased the percentage of dead cells at both time points. With either MPA concentration, FC-DDFT and FC-NB explants had reduced metabolic activity and an increased percentage of dead cells at 24 hours, whereas only MPA at 5 mg/mL was cytotoxic at the 6-hour time point.

CONCLUSIONS AND CLINICAL RELEVANCE

In ex vivo explants, TA was less cytotoxic to equine FC-DDFT and FC-NB cells, compared with MPA. Further work is warranted to characterize the drugs' transcriptional and translational effects as well as investigate their cytotoxicity at lower concentrations.

Effect of local anesthetics on viability and differentiation of various adult stem/progenitor cells

BACKGROUND

Local anesthetics (LAs) are widely used to control pain during various clinical treatments. One of the side effects of LAs, cytotoxicity, has been investigated in various cells including stem/progenitor cells. However, our understanding of the effects of LAs on the differentiation capacity of stem/progenitor cells still remains limited. Therefore, a comparative study was conducted to investigate the effects of multiple LAs on viability and multi-lineage differentiation of stem/progenitor cells that originated from various adult tissues.

METHOD

Multiple types of stem/progenitor cells, including bone marrow mesenchymal stem/progenitor cells (MSCs), dental pulp stem/progenitor cells (DPSCs), periodontal ligament stem/progenitor cells (PDLSCs), and tendon-derived stem/progenitor cells, were either obtained from a commercial provider or isolated from adult human donors. Lidocaine (LD) and bupivacaine (BP) at various doses (1×, 0.75×, 0.5×, and 0.25× of each physiological dose) were applied to the different stem/progenitor cells for an hour, followed by induction of fibrogenic, chondrogenic, osteogenic, and adipogenic differentiation. Live/dead and MTT assays were performed at 24 h after the LD or BP treatment. At 2 weeks, qRT-PCR was conducted to evaluate the gene expressions associated with differentiation. After 4 weeks, multiple biochemical staining was performed to evaluate matrix deposition.

RESULTS

At 24 h after LD or BP treatment, 1× and 0.75× physiological doses of LD and BP showed significant cytotoxicity in all the tested adult stem/progenitor cells. At 0.5×, BP resulted in higher viability than the same dose LD, with variance between cell types. Overall, the gene expressions associated with fibrogenic, chondrogenic, osteogenic, and adipogenic differentiation were attenuated in LD or BP pre-treated stem/progenitor cells, with notable dose-effect and dependence on types. In contrast, certain doses of LD and/or BP were found to increase specific gene expression, depending on the cell types.

CONCLUSION

Our data suggest that LAs such as LD and BP affect not only the viability but also the differentiation capacity of adult stem/progenitor cells from various anatomical sites. This study sheds light on stem cell applications for tissue regeneration in which isolation and transplantation of stem cells frequently involve LA administration.

Adverse Impact of Corticosteroids on Rotator Cuff Tendon Health and Repair: A Systematic Review of Basic Science Studies

Purpose

To evaluate the in vitro effects of corticosteroid injections (CSIs) on rotator cuff tendon (RCT).

Methods

A systematic review of the MEDLINE database was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for all studies reporting on adverse biochemical and biomechanical effects of CSIs on RCT.

Results

Sixteen studies were identified that had been published in the last 15 years on the effects of corticosteroids on RCTs. Eight of these studies were on human RCTs, 6 were on rat tendons, 1 considered both human and rat tendons, and 1 was on dog tendon. Five studies analyzed the effects of corticosteroids on the biomechanical properties of RCT or rotator cuff repair, whereas the remaining observed the cellular and molecular effects of CSIs on RCT. Corticosteroids suppress an inflammatory response, induce apoptosis, and have negative effects on collagen and tendon cell viability in RCTs. The mechanical properties, including load to failure of RCTs and rotator cuff repair anchor pull-out strength, also are decreased by CSIs. These in vitro effects appear to be transient as well as frequency and dose dependent.

Conclusions

On a molecular level, CSIs decrease cellular proliferation, alter collagen and extracellular matrix composition, impede inflammatory pathways, decrease cellular viability, increase adipocyte differentiation, and increase apoptosis. These changes can be seen as early as 24 hours after corticosteroid exposure, last as long as 2 to 3 weeks, and are exacerbated by increased doses and decreased latency between doses. Biomechanical studies demonstrate that these changes result in decreased maximal load to failure, tendon stiffness, and suture anchor pull-out strength in rat shoulders up to 2 weeks but not at 3 and 4 weeks, post-CSI.

Clinical Relevance

Shoulder subacromial steroid injection is common, and practitioners should be aware of results both positive and deleterious.

Nonbiologic Injections in Sports Medicine

Nonbiologic medications (local anesthetics, corticosteroids, and nonsteroidal anti-inflammatory drugs) are commonly administered to athletes for analgesia after injury. However, the risks of nonbiologic injections often are overlooked simply because of their long-term market availability. A thorough understanding of the mechanism of action, the reported benefits, and the potential risks of nonbiologic medications is crucial prior to their use, especially in the treatment of young athletes. Sports medicine physicians and surgeons must be aware of the systemic and local effects of these medications to ensure an appropriate drug choice that minimizes side effects and avoids recently reported toxicity to myocytes, tenocytes, and chondrocytes.

In Vivo Toxicity of Local Anesthetics and Corticosteroids on Supraspinatus Tenocyte Cell Viability and Metabolism

BACKGROUND

This study was conducted to evaluate the effects of commonly used injection medication combinations on supraspinatus tenocyte cell viability and tissue metabolism.

METHODS

Twenty adult dogs underwent ultrasound guided injection of the canine equivalent of the subacromial space, based on random assignment to one of four treatment groups (n=5/group): normal saline, 1.0% lidocaine/methylprednisolone, 1.0% lidocaine/triamcinolone or 0.0625% bupivacaine/triamcinolone. Full-thickness sections of supraspinatus tendon were harvested under aseptic conditions and evaluated on days 1 and 7 post-harvest for cell viability and tissue metabolism. Data were analyzed for significant differences among groups.

RESULTS

Tendons exposed to 1% lidocaine/ methylprednisolone had significantly lower cell viability at day 1 as compared to all other groups and control. All local anesthetic/ corticosteroid combination groups had decreased cell viability at day 7 when compared to the control group.

CONCLUSIONS

This study demonstrated significant in vivo supraspinatus tenotoxicity following a single injection of combination local anesthetic/ corticosteroid when compared to saline controls.

LEVEL OF EVIDENCE

Level II.