Ketorolac But Not Morphine Exerts Inflammatory and Metabolic Effects in Synovial Membrane After Knee Arthroscopy: A Double-Blind Randomized Prospective Study Using the Microdialysis Technique

Local and Intra-articular Administration of Nonsteroidal Anti-inflammatory Drugs for Pain Management in Orthopedic Surgery

BACKGROUND

Although growing evidence demonstrates the benefits of locally administered nonsteroidal anti-inflammatory drugs (NSAIDs) for postoperative pain management, there is ongoing debate regarding NSAID use in orthopedic surgery.

AREAS OF UNCERTAINTY

Current data largely support a local site of NSAID action and suggest that effective pain control can be achieved with delivery of NSAIDs intra-articularly (IA) and/or locally at the site of injury, where they can block peripheral production of inflammatory mediators and may desensitize nociceptors. Improvements in postoperative pain control with locally administered NSAIDs have been widely reported in the total joint arthroplasty literature and may offer benefits in patient's undergoing arthroscopic procedures and those with osteoarthritis as well. The purpose of this review is to examine the available evidence in the literature regarding the efficacy and safety profile of the use of local and IA NSAIDs in orthopedic surgery.

DATA SOURCES

Narrative literature review using keywords, expert opinion, either during or from live conference.

THERAPEUTIC ADVANCES

Local and IA administration of NSAIDs for pain management in orthopedic surgery.

CONCLUSION

There is convincing evidence that NSAIDs administered locally in and around the joint reduce postoperative pain scores and opioid consumption in patients undergoing total joint arthroplasty, yet further research is required regarding the risks of potential chondrotoxicity and the inhibition of bone and soft-tissue healing with locally administered NSAIDs.

Influence of Ketorolac Supplementation on Pain Control for Knee Arthroscopy: A Meta-Analysis of Randomized Controlled Trials

Introduction

The efficacy of ketorolac supplementation on pain control for knee arthroscopy remains controversial. We conduct a systematic review and meta‐analysis to explore the impact of ketorolac supplementation on pain intensity after knee arthroscopy.

Methods

We search PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases through September 2018 for randomized controlled trials (RCTs) assessing the effect of ketorolac supplementation vs placebo on pain management after knee arthroscopy. This meta‐analysis is performed using the random‐effect model.

Results

Ten RCTs involving 402 patients are included in the meta‐analysis. Overall, compared with control group for knee arthroscopy, ketorolac supplementation is associated with notably reduced pain scores at 1 h (MD = −0.66; 95% CI = −1.12 to −0.21; P = 0.004) and 2 h (MD = −0.90; 95% CI = −1.74 to −0.07; P = 0.03), prolonged time for first analgesic requirement (MD = 1.94; 95% CI = 0.33 to 3.55; P = 0.02) and decreased number of analgesic requirement (RR = 0.41; 95% CI = 0.23 to 0.75; P = 0.003), but has no obvious impact on analgesic consumption (MD = −0.56; 95% CI = −1.14 to 0.02; P = 0.06), as well as nausea and vomiting (RR = 0.44; 95% CI = 0.12 to 0.21; P = 0.21).

Conclusions

Ketorolac supplementation is effective to produce pain relief for knee arthroscopy.

The effects of intra-articular injection of ibuprofen on knee joint cartilage and synovium in rats

Objective

The aim of this animal study was to investigate the short and long-term local histomorphologic effects and the utility of intra-articular application of ibuprofen.

Methods

Forty-six Wistar Albino rats were used in the study. The rats were randomized into 5 groups of 8 and a sham group of 6. The 40 rats in the study groups were anaesthetised with 60 mg/kg of ketamine, then 0.25 ml ibuprofen (25 mg) was injected to the right knee joint of each rat (ibuprofen group) and 0.25 ml 0.9% saline to the left knee joint as the control group. To the 6 rats in the sham group, only puncture was applied to both knee joints. The rats in each of the 5 study groups were sacrificed on days 1, 2, 7, 14 and 21 respectively. The histomorphologic changes were graded on a 6-point scale regarding inflammation of the synovia, cartilage tissue, and subchondral bone. Inflammation scores were compared using the Mann Whitney U-test and comparisons of the sacrifice day and drug used were evaluated with the Kruskal Wallis test. The p values below 0.05 were considered as significant.

Results

Statistically significant difference was found between the ibuprofen injected knees (10/40) and the saline injected (0/40) and sham knees (0/12) in respect of hematoma positivity (p = 0.002). Significantly higher inflammation scores were found in ibuprofen injected knees on the 1st, 2nd, 7th and 14th days compared to controls and sham (p < 0.05). Inflammation scores were similar in ibuprofen injected knees with and without hematoma (p > 0.05). Inflammation of the ibuprofen injected group was most severe on day one and the severity of inflammation reduced gradually throughout the 3 weeks.

Conclusion

Our results show that intra-articular injection of ibuprofen can cause intra-articular hematoma. It also leads to transient inflammation of the synovia that is more severe in the early period, which gradually recovers.

Younger patients and smokers report a higher level of pain after knee arthroscopy: a clinical and experimental study including synovial metabolism

PURPOSE

Factors associated with post-surgical pain are not fully explored. The aim of this study was to identify determinants of postoperative pain after arthroscopic surgery of the knee. Synovial tissue metabolism was analysed by microdialysis and the association with individual and peri-surgical factors to identify determinants important for pain management and thus patient satisfaction.

METHODS

Cross-sectional study of 57 patients (22 women) with median age of 39 years. All patients were operated on with arthroscopic surgery of the knee and monitored postoperatively with synovial microdialysis. The cross-sectional cohort was investigated to determine local tissue levels of inflammatory and metabolic compounds along with postoperative pain experience.

MEASUREMENTS

pain was determined by visual analogue scale (VAS). Postoperative synovial tissue levels of prostaglandin E₂ (PGE₂), glucose, and glycerol were measured by microdialysis in the knee synovium. Patients reporting VAS ≥ 4 received rescue pain medication with systemic opioids.

RESULTS

Initial results indicated that patients with pain (interpreted as having VAS ≥ 4), i.e. those receiving rescue medication with systemic opioids, were of a younger age (p = 0.04), lower body weight (p = 0.02), had a lower BMI (p = 0.04) and/or were smokers (p = 0.02). A closer analysis using multinomial logistic regression showed a significantly higher amount of pain in smokers (p = 0.01) and patients of a younger age (p = 0.02). A significant correlation was also found between VAS and duration of surgery (p = 0.007). No significant correlation could be found between VAS and synovial levels of PGE₂, glycerol and glucose, but a statistically significant decline with time of PGE₂ in both groups.

CONCLUSIONS

The results from this study show a significantly higher frequency of pain, post-surgery among younger patients (p = 0.02) and smokers (p = 0.01), as well as an association between pain and length of surgery (p = 0.007). These findings point out individual factors useful for the prediction of postoperative pain after arthroscopic surgery and are clinically important for personalized pain management.

LEVEL OF EVIDENCE

II.

Randomized controlled trial of intra-articular ketorolac on pain and inflammation after minor arthroscopic knee surgery

BACKGROUND

Ketorolac is an effective non-steroidal anti-inflammatory drug, commonly used with local anaesthetics as part of local infiltration analgesia protocols following orthopaedic surgery. However, systemic uptake and drug action may be the major mechanism after local infiltration. The aims of this project were to study the effects of a small, systemically ineffective dose of ketorolac given intra-articularly for post-operative pain and also to study synovial inflammatory biomarkers. We investigated whether ketorolac affects pro-inflammatory biomarkers in an in vitro model, as well.

METHODS

In this placebo-controlled, blind, randomized study, we analysed intra-articular ketorolac (5 mg) in ambulatory minor knee surgery patients with moderate or severe pain (n = 44). We assessed post-operative pain intensity (n = 44) and analysed microdialysis samples taken from knee synovial tissue every 20 min (n = 34). We also tested cyclooxygenase-independent effects of ketorolac in synovial cells stimulated by prostaglandin E₂ and chondroitin sulphate in vitro.

RESULTS

Intra-articular ketorolac (5 mg) administration did not reduce pain or synovial pro-inflammatory cytokines CXCL1, IL-8, and MCP-1, 0-120 min after knee arthroscopy. Female gender was a risk factor for moderate or severe pain (relative risk 1.45, 95% confidence interval 1.04-2.01). Paradoxically, ketorolac increased the release of CXCL1 and IL-8 in prostaglandin E₂ and chondroitin sulphate-stimulated synovial cells in vitro.

CONCLUSION

Ketorolac prescribed at a low dose intra-articularly does not produce any detectable analgesic effect after minor knee surgery.

Intra-articular tibiofemoral injection of a nonsteroidal anti-inflammatory drug has no detrimental effects on joint mechanics in a rat model

Administration of intra-articular medications, including corticosteroids and analgesics, is common clinical practice for knee pathology and dysfunction. Non-steroidal anti-inflammatory drugs (NSAIDs) are another category of medication commonly prescribed for their analgesic and anti-inflammatory properties. Recent studies demonstrated the efficacy of injectable NSAIDs in the treatment of intra-articular pathology and postoperative analgesia. However, little data exist regarding the safety of intra-articular injection, despite the increase in its application. Therefore, we investigated the effects of intra-articular NSAID injection on articular cartilage, the anterior cruciate ligament (ACL), and joint function in the rat. Sixty-four Sprague-Dawley rats were divided into either saline (SAL) or ketorolac (NSAID) tibiofemoral single injection treatment groups. Animals were euthanized at 2, 7, 28, and 84 days post-injection for histological and mechanical analyses. Additionally, a subset of animals underwent longitudinal ambulatory evaluation to determine joint functional properties. We hypothesized that intra-articular ketorolac injection would result in no detrimental mechanical, histological, or functional changes. No differences were reported between the NSAID and SAL groups in any of the parameters measured at any time point, demonstrating the potential safety of intra-articular NSAID administration. Therefore, NSAID injection could be further considered for clinical application in humans.

Targeting inflammation and wound healing by opioids

Opioid receptors are expressed on peripheral sensory nerve endings, cutaneous cells, and immune cells; and local application of opioids is used for the treatment of inflammatory pain in arthritis, burns, skin grafts, and chronic wounds. However, peripherally active opioids can also directly modulate the inflammatory process and wound healing. Here, we discuss the underlying mechanisms of opioid action and the conceivable therapeutic approaches for opioid treatment, as investigated in experimental and clinical studies. A large number of in vitro experiments and animal model investigations have produced evidence that peripherally active opioids can reduce plasma extravasation, vasodilation, proinflammatory neuropeptides, immune mediators, and tissue destruction. In contrast to currently available anti-inflammatory agents, opioids have not demonstrated organ toxicity, thus making them interesting candidates for drug development. Few clinical studies have tapped into this potential to date.

Temperature-sensitive release of prostaglandin E₂ and diminished energy requirements in synovial tissue with postoperative cryotherapy: a prospective randomized study after knee arthroscopy

BACKGROUND

Local external cooling of the surgical field after joint surgery is intended to enhance recovery and to facilitate the use of outpatient surgery by reducing pain and improving mobility. We hypothesized that the effects of postoperative cooling and compression after knee arthroscopy would be reflected in changes in the concentrations of metabolic and inflammatory markers in the synovial membrane.

METHODS

Forty otherwise healthy patients who were to undergo knee arthroscopy were included in the study, and half were randomized to receive postoperative cooling and compression. Microdialysis of the synovial membrane was performed postoperatively, and the concentrations of prostaglandin E₂ (PGE₂), glucose, lactate, glycerol, and glutamate as well as the ethanol exchange ratio (which indicates blood flow) were measured. The temperature of the knee was monitored, and postoperative pain was assessed by the patient with use of a visual analog scale, a numeric rating scale, and the need for rescue medication.

RESULTS

Application of the cooling and compression device after knee arthroscopy significantly lowered the temperature in the operatively treated knee (as measured on the skin, within the joint capsule, and intra-articularly). The cooling and compression appeared to decrease inflammation, as indicated by a temperature-sensitive decrease in the PGE₂ concentration. The hypothermia also decreased the metabolic rate of the synovial tissue and thus decreased energy requirements, as shown by the stability of the lactate concentration over time despite the decreased blood flow that was indicated by the increasing ethanol exchange ratio. No effect of the compression and cooling on postoperative pain was detected.

CONCLUSIONS

Local cryotherapy and compression after knee arthroscopy significantly lowered the temperature in the knee postoperatively, and the synovial PGE₂ concentration was correlated with the temperature. Since PGE₂ is a marker of pain and inflammation, the postoperative local cooling and compression appeared to have a positive anti-inflammatory effect.

Knee arthroscopy routines and practice

PURPOSE

Knee arthroscopy is one of most commonly performed day-case orthopaedic procedures, thus consuming huge medical resources. The aim of the present questionnaire survey was to study knee arthroscopy routines and practice.

METHODS

An electronic web-based survey including questions around pre-, per- and postoperative routines for elective knee arthroscopy was send to all orthopaedic units associated to the Swedish Arthroscopic Society (n = 60).

RESULTS

Responses covering 37 centres out of 60 (response rate 62%) were returned. Preoperative radiograph routines varied considerable between centres; conventional radiograph varied between 5 and 100% and preoperative MRI between 5 and 80% of patients. General anaesthesia was the preferred intra-operative technique used in all centres (median 79% of patients), local anaesthesia with or without light sedation was used in all 28 out of the 37 centres responding (median 10% of cases) and spinal anaesthesia was used in 15 centres (median 5% of cases). Intra-articular local anaesthesia was provided in all but one of centres. Perioperative administration of oral NSAIDs was common (31 out 37), 6 centres (all teaching hospitals) did not routinely give pre- or postoperative NSAID. Analgesic prescription was provided on a regular base in 18 (49%) of centres; an NSAID being the most commonly prescribed. All but one centre provided written information and instruction at discharge. Referral to physiotherapy, prescribed sick leave and scheduled follow-up in the outpatient clinic diverged considerably.

CONCLUSION

Routines and practice associated to elective knee arthroscopy differed; however, no clear differences in practice were seen between teaching centres, general or local hospitals apart from a lower usage of NSAID for perioperative analgesia. There is an obvious room for further standardisation in the routine handling of patients undergoing elective arthroscopy of the knee.