The intra-articular use of ropivacaine for the control of post knee arthroscopy pain

Efficacy and safety of intra-articular glucocorticoid injection for postoperative pain control after knee arthroscopy: a systematic review

PURPOSE

Pain following arthroscopic knee surgery remains a controversial clinical problem. Intra-articular (IA) glucocorticoid injections have demonstrated the potential to provide better analgesia in some orthopedic surgeries; however, due to the lack of studies, its role in knee arthroscopies remain unclear. This systematic review aimed to evaluate the efficacy and safety of intra-articular glucocorticoids after arthroscopic knee surgery.

METHODS

A systematic review was conducted according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guideline, with literature search performed on Medline, Embase, and the Cochrane Library. This systematic review has been registered with the International Prospective Register of Systematic Reviews (PROSPERO; ID: CRD42024509749). Inclusion criteria included randomized controlled trials published in English comparing IA glucocorticoid to placebo in patients undergoing knee arthroscopy. Risk of bias for all included studies was assessed using the Cochrane Collaboration's risk of bias tool. Clinical outcomes compared were pain score: visual analogue scale (VAS) or International Knee Documentation Committee (IKDC), time to first analgesia requirement, analgesia consumption, range of motion (ROM), patient satisfaction, and complications.

RESULTS

A total of 7 studies (3 and 4 with evidence level I and II, respectively) involving 309 patients were included. All studies showed that IA glucocorticoids significantly decreased subjective pain scores. Three studies showed significantly longer duration to first postoperative analgesia use, while 6 showed significantly reduced postoperative analgesic administration with IA glucocorticoid use. Two studies showed significantly increased patient satisfaction with IA glucocorticoid (P = 0.001 and P = 0.01, respectively). No studies showed significant differences in complications such as nausea, vomiting, bradycardia, hypotension, or procedure-related adverse effects between the groups.

CONCLUSION

Current available randomized controlled trials suggest that IA glucocorticoids can significantly reduce postoperative pain, delay, and minimize postoperative analgesia use, and improve patient satisfaction. No postoperative complications or adverse events were reported, reflecting its safety as a postoperative analgesic modality.

Sublingual sufentanil tablet system (SSTS) versus a single shot peri-nervous injection of ropivacaine for the management of postoperative pain after total knee arthroplasty: a single-center randomized trial

INTRODUCTION

For several years, ropivacaine has been the standard-of-care for establishing postoperative femoral nerve block in total knee arthroplasty (TKA) setting and is still widely in use but new approaches such as the patient-controlled administration of sublingual sufentanil tablets system (SSTS) seem to offer good clinical results. Our aim is to compare the SSTS to single shot peri-nervous injection of ropivacaine (single shot) after TKA in terms of effectiveness in pain management and of time to recovery.

MATERIALS AND METHODS

A total of 165 patients undergoing TKA were enrolled. Eighty-four patients were randomly allocated in the SSTS group and 81 patients in the single shot group. The primary objective of the study was to evaluate performance of Timed Up and Go test. Secondary objectives were to measure the length of stay, NRS pain scale, the adherence to the prescribed plan, the joint mobility, the frequency of rescue analgesic use, side effects and patients' satisfaction.

RESULTS

Of all patients of the single shot group, 64 were withdrawn from the study as they unable to achieve pain control; only one patient was withdrawn from the SSTS group. Times for the "Timed Up and Go" test on the 3rd postoperative day were 8.4 ± 1.6 and 11.8 ± 3.6 in the SSTS group (n = 83) and single shot group (n = 17), respectively (p < .001).

CONCLUSIONS

SSTS provides better pain management when compared to peri-nervous ropivacaine single shot injection after TKA.

The Intra-Articular Combination of Fentanyl, Dexamethasone, Clonidine, Ropivacaine, and Dextrose to Treat Pain Due to Knee Osteoarthritis: A Case Report

We report a case involving the pain management of a patient with knee osteoarthritis (KOA), where conventional treatment failed to provide pain relief. Instead, a multimodal approach including an intra-articular (IA) injection of a combination of various agents was applied successfully. The pharmacological treatment resulted in minimal improvement. After experiencing failure with IA hyaluronic acid and platelet-rich plasma injections, an IA combination of fentanyl 50 mcg, dexamethasone 8 mg, clonidine 150 mcg, ropivacaine 7.5% 5 ml, dextrose 30% 5 ml, and normal saline 5 ml was applied. The treatment led to a two-year pain relief. The multimodal approach seems to offer satisfactory and encouraging results as the improvement in the quality of life led to favorable physical and psychological outcomes in the patient.

[Translated article] Postsurgical analgesic efficacy by the intra-articular administration of ropivacaine with dexmedetomidine versus simple ropivacaine in patients undergoing knee arthroscopy

The effective relief of postsurgical pain in patients undergoing knee arthroscopy is important to allow the initiation of activities of daily living. The objective of this study is to demonstrate the analgesic efficacy of dexmedetomidine as an adjuvant added to ropivacaine by the intra-articular route.

METHOD

Seventy patients underwent knee arthroscopy which were randomly assigned into two groups (n=35). The RD group received ropivacaine 1.5mg/kg plus dexmedetomidine 1μg/kg intra-articularly. Group R received ropivacaine 1.5mg/kg intra-articularly. The analgesic effect was evaluated by measuring the intensity of pain (VAS score) and the duration of analgesia.

RESULTS

A longer duration of the analgesic effect was observed in the RD group (655min) compared to the R group (318min) being statistically significant (p=0.03).

CONCLUSION

Dexmedetomidine as an adjuvant to intra-articular ropivacaine improves the quality and duration of postoperative analgesia in patients undergoing knee arthroscopy.

Postsurgical analgesic efficacy by the intra-articular administration of ropivacaine with dexmedetomidine versus simple ropivacaine in patients undergoing knee arthroscopy

The effective relief of postsurgical pain in patients undergoing knee arthroscopy is important to allow the initiation of activities of daily living. The objective of this study is to demonstrate the analgesic efficacy of dexmedetomidine as an adjuvant added to ropivacaine by the intra-articular route.

METHOD

Seventy patients underwent knee arthroscopy which were randomly assigned into two groups (n=35). The RD group received ropivacaine 1.5mg/kg plus dexmedetomidine 1μg/kg intra-articularly. Group R received ropivacaine 1.5mg/kg intra-articularly. The analgesic effect was evaluated by measuring the intensity of pain (VAS score) and the duration of analgesia.

RESULTS

A longer duration of the analgesic effect was observed in the RD group (655min) compared to the R group (318min) being statistically significant (p=0.03).

CONCLUSION

Dexmedetomidine as an adjuvant to intra-articular ropivacaine improves the quality and duration of postoperative analgesia in patients undergoing knee arthroscopy.

The In Vivo Chondrotoxicity of Single Intra-articular Injection of Local Anesthetic in Rat Cartilage

Introduction A constant infusion of local anesthetics through pain pumps has been shown to cause chondrolysis. However, there is no general consensus regarding the safety of a single intra-articular injection of local anesthetics. In this experimental study, we examined the rat cartilage for possible histological effects after a single intra-articular administration of lidocaine or ropivacaine. Material and methods Thirty-two male Sprague-Dawley rats, weighing 250-300 grams, were divided into two groups of 16 each. We injected 0.1 ml of either lidocaine 2% (20 mg/ml) or ropivacaine 0.75% (7.5 mg/ml) into the left knee of the rats. The right knee in both groups was used as a control, and an equal amount of normal saline was injected. Each group was further divided into subgroups of four, which were euthanized after one, seven, 21, and 60 days after the initial injection. Knees were excised and prepared for histopathological analysis. A modified version of the Mankin score was used for cartilage damage evaluation. Results No difference regarding cartilage damage was detected after the examination under light microscopy between lidocaine, ropivacaine, and placebo in all specimens. Time elapsed since the initial injection did not affect the results at any time point. Conclusion A single intra-articular injection of local anesthetic did not induce any histological changes in the rat cartilage. Further research is needed to demonstrate the safety of humans.

Periarticular Injections in Knee and Hip Arthroplasty: Where and What to Inject

BACKGROUND

Periarticular injections have become a valuable adjunct to multimodal pain control regimens after knee and hip arthroplasties. Injection techniques vary greatly among surgeons with little standardization of practice.

METHODS

We performed an extensive literature search to determine where nociceptive pain fibers are located in the hip and the knee and also to explore the pharmacology of periarticular cocktail ingredients.

RESULTS

Large concentrations of nociceptors are present throughout the various tissues of the knee joint with elevated concentrations in the infrapatellar fat pad, fibrous capsule, ligament insertions, periosteum, subchondral bone, and lateral retinaculum. Less empiric evidence is available on nociceptor locations in the hip joint, but they are known to be located diffusely throughout the hip capsule with elevated concentrations at the labral base and central ligamentum teres. Local anesthetics are the base ingredient in most injection cocktails and function by blocking voltage-gated sodium channels. Liposomal anesthetics may offer longer duration of action over traditional anesthetics. Nonsteroidal anti-inflammatory agents and corticosteroids block peripheral production of inflammatory mediators and may desensitize nociceptors. Opioid receptors are present in lower densities peripherally as compared with the central nervous system, but their inclusion in injections can lead to pain relief. Sympathetic drugs can provide adjunct effects to periarticular cocktails to increase duration of action and effectiveness of medications.

CONCLUSION

Targeting specific sites of nociceptors may help to further decrease pain after knee and hip arthroplasties. Altering periarticular cocktail ingredients may aid in multimodal pain control with injections.

Pain relief in day care arthroscopic knee surgery: A comparison between intra-articular ropivacaine and levobupivacaine: A prospective, double-blinded, randomized controlled study

Background:

Post-operative pain frequently hampers implementation of day care arthroscopic knee surgery in spite of so many analgesic, local anesthetic drugs and routes of administration.

Aims:

The aim of the present study was carried out to compare the efficacy of ropivacaine and levobupivacaine when administered through intra-articular route in controlling pain after day care arthroscopic knee surgery.

Setting and Design:

It was a prospective, double-blinded and randomized controlled study.

Materials and Methods:

April 2008-December 2008, 60 patients of both sex, of American Society of Anesthesiologists physical status I and II, undergoing day care arthroscopic knee surgery were randomly assigned into two groups (R, L). Group R received 10 ml of 0.75% ropivacaine, whereas group L received 10 ml of 0.50% levobupivacaine through intra-articular route at the end of the procedure. Pain assessed using visual analog scale (VAS) and diclofenac sodium given as rescue analgesia when VAS >3. Time of first analgesic request and total rescue analgesic were calculated.

Statistical Analysis and Results:

based on comparable demographic profiles; time for the requirement of first post-operative rescue analgesia (242.16 ± 23.86 vs. 366.62 ± 24.42) min and total mean rescue analgesic requirement was (104.35 ± 18.96 vs. 76.82 ± 14.28) mg in group R and L respectively. Group R had higher mean VAS score throughout the study period. No side effects found among the groups. These two results were clinically and statistically significant (P < 0.05).

Conclusion:

Hence, it was evident that intra-articular levobupivacaine give better post-operative pain relief, with an increase in time of first analgesic request and decreased need of total post-operative analgesia compared with ropivacaine.

Pain relief after Arthroscopic Knee Surgery: A comparison of intra-articular ropivacaine, fentanyl, and dexmedetomidine: A prospective, double-blinded, randomized controlled study

Background:

Postoperative pain is very common distressing symptom after any surgical procedure. Different drugs in different routes have been used for controlling post-arthroscopic pain. No one proved to be ideal. We have compared the analgesic effect of ropivacaine, fentanyl, and dexmedetomidine when administered through the intra-articular route in arthroscopic knee surgery.

Materials and Methods:

From March 2008 to July 2010, 99 patients undergoing arthroscopic knee surgery were randomly assigned into three groups (A,B,C) in a prospective double-blinded fashion. Group A received 10 ml of 0.75% ropivacaine, where Group B received 50 μg fentanyl, and Group C received 100 μg of dexmedetomidine through the intra-articular route at the end of procedure. Pain assessed using visual analog scale and diclofenac sodium given as rescue analgesia when VAS >4. Time of first analgesia request and total rescue analgesic used in 24 hours were calculated.

Results:

Demographic profiles are quite comparable among the groups. Time for requirement of first postoperative rescue analgesia in Group A was 380.61 ± 22.973 min, in Group B was 326.82 ± 17.131 min and in Group C was 244.09 ± 20.096 minutes. Total rescue analgesia requirement was less in Group A (1.394 ± 0.496) compared to Group B (1.758 ± 0.435) and Group C (2.546 ± 0.546). Group A had higher mean VAS score at 6^th and 24^th postoperative hours. No side effects found among the groups.

Conclusion:

Therefore, it suggests that intra-articular ropivacaine gives better postoperative pain relief, with increased time of first analgesic request and decreased need of total postoperative analgesia compared to fentanyl and dexmedetomidine.

A randomized controlled trial for the effectiveness of intraarticular versus intravenous midazolam on pain after knee arthroscopy

BACKGROUND

This double-blinded, randomized clinical trial was designed to evaluate the comparison of intravenous versus intraarticular (IA) administration of midazolam on postoperative pain after knee arthroscopy.

MATERIALS AND METHODS

In this study, 75 patients randomized in three groups to receive 75 mc/kg IA injection of midazolam and 10 ml intravenous injection of isotonic saline (Group I), 75 mc/kg intravenous injection of midazolam and 10 cc IA injection of isotonic saline (Group II) or IA and intravenous injection of isotonic saline (Group III) at the end of knee arthroscopy. Pain scores, time until the first request for analgesics, cumulative analgesic consumption, satisfaction, sedation, and complications as studied outcomes were assessed. Patients were observed for 24-h.

RESULTS

IA administration of midazolam significantly reduced pain scores in the early postoperative period compared with intravenous injection. Mean of time to first analgesic requirement in Group III (33.6 min) was significantly lower than Group II (288.8 min) and Group I (427.5 min). Cumulative analgesic consumption was increased in Groups II (35.5 mg), and III (70 mg) compared with Group I (16 mg), (P < 0.0001). Complications significantly occurred in 3 of 25 patients in Group I in contrast to 20 of 25 patients in Group III (P < 0.0001). At 2-, 4- and 8-h after arthroscopy pain score significantly decreased in Group I than other groups (P < 0.0001). Patients in Group I were significantly satisfy than other groups (P < 0.0001).

CONCLUSION

Results show the greater analgesic effect after IA administration of midazolam than after intravenous injection and hence, IA administration may be is the method of choice for pain relief after knee arthroscopy.

Impact of local anaesthetics and needle calibres used for painless PRP injections on platelet functionality

The platelet-rich plasma (PRP) is an autologous biotherapy commonly used for its healing properties. Once activated, platelets released a real "cocktail" of growth factor and cytokines implied in numerous regenerative processes. However the impact of medical practices associated to PRP therapeutic use on platelets functionality remains poorly known.

OBJECTIVES

we evaluated the in vitro effects of two commonly used local anesthetics (Xylocaine(*) and Naropin(*)) on PRP functionality. We also investigated the quantity and quality of PRP that passed through the smallest gauge needle commercialized.

MATERIALS AND METHODS

PRP from 9 healthy volunteers were prepared using our previously described home made purification protocol. Platelet aggregation capacity was evaluated by aggregometry assays and the growth factor release was determined by ELISA after platelet activation. We also evaluated the platelet activation status, reactivity and stability of platelets by flow cytometry using the P-selectin expression marker.

RESULTS

the association of local anaesthetics with PRP injections resulted in a significant decrease of platelets functionality, assessed by their capacity of aggregating. Local anaesthetics did not interfere with the growth factor release. The different needle sizes and calibres tested for PRP injections did not influence the platelet functionality.

CONCLUSIONS

the use of local anaesthetics to prevent pain during PRP injections could compromise the therapeutic potential of PRP. These results suggest using carefully local anaesthetics or limiting their use as often is possible. To minimize injection pain, we recommend using 30 G needles. These data will lead to clinical recommendations for painless and controlled PRP injections.

Extended release local anesthetic agents in a postoperative arthritic pain model

Local anesthetics play an important role in postoperative pain management in orthopedic joint procedures. The aim of this study was to determine the effect of an intraoperative extra-articular injection of poly(DL-lactic acid co castor oil 3:7), p(DLLA:CO) 3:7 loaded with 15% bupivacaine, for postoperative analgesia following knee arthroplasty. Prolonged release local anesthetic formulation was synthesized by mixing p(DLLA:CO) 3:7 with bupivacaine base. Under anesthesia, the knee joint of Sprague-Dawley rats was exposed, a hole drilled in the femoral trochlea. 0.2 mL of either 15% polymer-bupivacaine formulation or plain bupivacaine (control) was injected locally and compared with a nonsurgery control group. Mechanical hyperalgesia was determined by counting the vocalizations and leg withdrawal after joint squeezing. Behavioral assessments over a day postoperative period revealed a reduction in rearing and ambulation in an open-field apparatus in animals of both experimental groups compared with the nonsurgery control. The vocalizations during the hyperalgesia test increased compared with the control at 24 h. At 48 h, 3.667 ± 0.5138, p = 0.0076 vocalizations were recorded for the plain bupivacaine group versus 1.417 ± 0.5138, p < 0.0001 in the 15% polymer-bupivacaine formulation. Bupivacaine encapsulated in p(DLLA:CO) 3:7 extended the duration of the analgesia compared with plain drug in rats and could represent effective postoperative analgesic in orthopedic joint procedures.

Preemptive analgesia with intra-articular pethidine reduces pain after arthroscopic knee surgery

Background:

Postoperative pain relief is important in procedures of the lower extremity. Several previous studies have evaluated the efficacy of intra-articular (IA) pethidine as a compound, which has local anesthetic and opioid agonist properties, on postoperative pain relief in arthroscopic knee surgery (AKS). This study compared the postoperative analgesic effect of pre- and post-surgical IA pethidine administration in AKS.

Materials and Methods:

Seventy-five patients of American Society of Anesthesiologists (ASA) I and II undergoing AKS with general anesthesia were enrolled in this double-blind study. Patients were randomized in three equal groups to receive either 50 mg IA pethidine before surgical incision incision and saline after skin closure (PS), saline before surgical incision and pethedine after skin closure (SP), and only saline at two different times (SS). In each patient with operated knee joint, pain at rest and joint movement was evaluated at 1, 2, 6, 12, and 24 h after surgery completion using Visual Analog Scale (VAS). Data were analyzed using analysis of variance (ANOVA)-repeated measure, t-paired, and Chi-square tests.

Results:

Postoperative pain score at rest and joint movement in PS group was significantly lower than those in other groups. The time (Mean ± SD) between completion of operation and patient's request for morphine, total morphine consumption (Mean ± SD) in postoperative 24 h, and the numbers of patients requesting analgesic in PS, SP, SS, groups were: 5.2 ± 1.3, 3.3 ± 1.5, and 2 ± 1.3 h (P < 0.05); 4.4 ± 2.4, 8.7 ± 2, and 11.6 ± 4.4 mg (P < 0.05); 11, 18, and 21 persons (P < 0.05), respectively.

Conclusion:

The present study shows that preemptive intra-articular pethidine 50 mg injection is more effective than preventive injection for postoperative pain relief at rest and joint movement in arthroscopic knee surgery.

The effect of intraarticular combinations of tramadol and ropivacaine with ketamine on postoperative pain after arthroscopic meniscectomy

INTRODUCTION

The purpose of this prospective randomized study was to evaluate the effects of intraarticular combinations of tramadol and ropivacaine with ketamine in postoperative pain control of patients undergoing arthroscopic meniscectomy.

MATERIALS AND METHODS

We randomly divided 80 patients into four groups to receive intraarticular 50 mg tramadol (Group T), 50 mg tramadol with 0.5 mg kg(-1) ketamine (Group TK), 75 mg ropivacaine (Group R), 75 mg ropivacaine with 0.5 mg kg(-1) ketamine (Group RK) in 20 ml normal saline at the end of surgery. Postoperative analgesia was provided with patient-controlled analgesia with morphine. Postoperative pain scores, total morphine consumption amount and side effects were recorded at intervals of 0, 1, 2, 4, 8, 12 and 24 h after the operation.

RESULTS

Pain scores were higher in Group T when compared with Group R and Group RK at second and fourth hours, also compared with Group RK at zeroth, first, second, fourth and eighth hours. Total morphine consumption amount was found to be higher in Group T when compared to Group TK at eighth and twelfth hours and Group RK at eighth hours (P < 0.05). Total morphine consumption was lowest in Group TK (P < 0.05). There were no significant differences among the study groups regarding side effects.

CONCLUSIONS

Administration of intraarticular tramadol-ketamine combination was found to be more effective in decreasing postoperative daily analgesic consumption.

Is chemical incompatibility responsible for chondrocyte death induced by local anesthetics?

BACKGROUND

Chondrolysis associated with intra-articular administration of local anesthetics has been attributed to chondrocyte death induced by the local anesthetics. The mechanism of how the local anesthetics cause chondrocyte death is not clear.

PURPOSE

This study was conducted to determine whether and how the local anesthetics cause chondrocyte death.

STUDY DESIGN

Controlled laboratory study.

METHODS

Bovine articular chondrocytes in suspension culture were treated for 1 hour with phosphate-buffered saline or phosphate-buffered saline/medium mixture (as controls); 1% lidocaine alone; 0.25% to 0.5% bupivacaine alone; phosphate-buffered saline with pH values of 4.5, 3.8, 3.4, and 2.4; or mixtures of the local anesthetics and cell culture medium or human synovial fluid. Chondrocyte viability was analyzed by flow cytometry using the LIVE/DEAD Viability/Cytotoxicity Kit.

RESULTS

In 1% lidocaine-alone or 0.25% to 0.5% bupivacaine-alone groups, the rate of cell death was 11.8% to 13.3% of bovine articular chondrocytes, whereas the phosphate-buffered saline control had 8.4% of cell death. Increased chondrocyte death was only found when the pH value of phosphate-buffered saline dropped to < or = 3.4. In contrast, when bupivacaine was mixed with cell culture medium, needle-like crystals were formed, which was accompanied with 100% death of chondrocytes. Lidocaine did not form visible crystals when it was mixed with culture medium, but the mixtures caused death of over 96% of chondrocytes (P < .001).

CONCLUSION

Less than 5% of chondrocyte death was attributable to the anesthetics when applied to the cells alone or in phosphate-buffered saline-diluted solution. Acidity (as low as pH 3.8) or epinephrine in the anesthetic solutions could not account for chondrocyte death. However, chemical incompatibility between the local anesthetics and cell culture medium or human synovial fluid may be the cause of chondrocyte death.

CLINICAL RELEVANCE

Intra-articular administration of lidocaine and bupivacaine is not an indicated usage of either anesthetic, although such a usage has become a common practice. Physicians should be aware of the potential incompatibility of the drug and synovial fluid.

Aspiration alone versus aspiration and bupivacaine injection in the treatment of undisplaced radial head fractures: a prospective randomized study

HYPOTHESIS

Some physicians advocate that aspiration of elbow joint hematoma in radial head fractures is helpful not only for determining a mechanical block to motion from a fracture fragment but also for improving the elbow motion and pain. However, the supplementary role of intra-articular anaesthetic injection is unclear.

MATERIALS AND METHODS

In this prospective randomized study, 40 patients with undisplaced radial head fractures (Mason I) were treated with elbow joint aspiration alone (20 patients) or aspiration plus intra-articular injection of 3 mL of bupivacaine 0.5% (20 patients). Active elbow exercises were immediately commenced. The patients were evaluated at 1 day, 1, 3, and 6 weeks, 3 and 6 months, and 1 year.

RESULTS

No difference was found in terms of range of motion, pain and elbow function between the 2 groups in all the examined time points. The improvement in the above parameters achieved a plateau at 3 weeks in both groups.

DISCUSSION

Intra-articular use of local anaesthetic after joint aspiration does not offer any benefit over aspiration alone in the treatment of undisplaced radial head fractures and its routine application is not supported by the clinical data.

Comparison of ropivacaine and bupivacaine toxicity in human articular chondrocytes

BACKGROUND

It has been shown that bupivacaine, the most commonly used local anesthetic for postoperative intra-articular use, is cytotoxic to bovine articular chondrocytes in vitro. Ropivacaine is as effective as bupivacaine for intra-articular analgesia and has less systemic toxicity. We compared the in vitro viability of human articular chondrocytes after exposure to bupivacaine, ropivacaine, and saline solution control.

METHODS

Macroscopically normal human articular cartilage was harvested from the femoral head or tibial plateau of five patients. Full-thickness cartilage explants and cultured chondrocytes isolated from these patients were treated with 0.9% normal saline solution, 0.5% ropivacaine, or 0.5% bupivacaine for thirty minutes. Twenty-four hours after treatment, chondrocyte viability was measured with use of the LIVE/DEAD Viability/Cytotoxicity Kit for cartilage explants and with use of the CellTiter-Glo Luminescent Cell Viability Assay for cultured chondrocytes.

RESULTS

Chondrocyte viability in cartilage explants was significantly greater after treatment with ropivacaine as compared with bupivacaine (94.4% +/- 9.0% compared with 78% +/- 12.6%; p = 0.0004). There was no difference in viability after treatment with ropivacaine as compared with saline solution (94.4% +/- 9.0% compared with 95.8% +/- 5.7%; p = 0.6). The viability of cultured chondrocytes was significantly greater after treatment with ropivacaine as compared with bupivacaine (63.9% +/- 19% as compared with 37.4% +/- 12% of the value in the saline solution group; p < 0.0001).

CONCLUSIONS

In vitro, 0.5% ropivacaine is significantly less toxic than 0.5% bupivacaine in both intact human articular cartilage and chondrocyte culture.