Cox-2 inhibition and the composition of inflammatory cell populations during early and mid-time tendon healing

Peritendinous adhesion: Therapeutic targets and progress of drug therapy

Peritendinous adhesion (PA) is one of the most common complications following hand surgery and characterized with abnormal hyperplasia of connective tissue and excessive deposition of extracellular matrix. Subsequently, various clinical symptoms such as chronic pain, limb dyskinesia and even joint stiffness occur and patients are always involved in the vicious cycle of "adhesion - release - re-adhesion", which seriously compromise the quality of life. Until present, the underlying mechanism remains controversial and lack of specific treatment, with symptomatic treatment being the only option to relieve symptoms, but not contributing no more to the fundamentally rehabilitation of basic structure and function. Recently, novel strategies have been proposed to inhibit the formation of adhesion tissues including implantation of anti-adhesion barriers, anti-inflammation, restraint of myofibroblast transformation and regulation of collagen overproduction. Furthermore, gene therapy has also been considered as a promising anti-adhesion treatment. In this review, we provide an overview of anti-adhesion targets and relevant drugs to summarize the potential pharmacological roles and present subsequent challenges and prospects of anti-adhesion drugs.

[Research progress on early postoperative pain management strategies after arthroscopic anterior cruciate ligament reconstruction]

Objective

To summarize the early postoperative pain management strategies for anterior cruciate ligament reconstruction (ACLR), and to select a reasonable and effective pain management plan to promote functional rehabilitation after ACLR.

Methods

The literature about the early postoperative pain management strategies of ACLR both domestically and internationally in recent years was extensiverly reviewed, and the effects of improving postoperative pain were reviewed.

Results

Currently, physical therapy and oral medication have advantages such as economy and simplicity, but the effect of improving postoperative pain is not satisfactory, often requires a combination of intravenous injection or intravenous pump, which is also a common way to relieve pain. However, in order to meet the analgesic needs of patients, the amount of analgesic drugs used is often large, which increases the incidence of various adverse reactions. Local infiltration analgesia (LIA), including periarticular or intra-articular injection of drugs, can significantly improve the early postoperative pain of ACLR, and achieve similar postoperative effectiveness as nerve block. LIA can be used as an analgesic technique instead of nerve block, and avoid the corresponding weakness of innervated muscles caused by nerve block, which increases the risk of postoperative falls. Many studies have confirmed that LIA can alleviate postoperative early pain in ACLR, especially the analgesic effects of periarticular injection are more satisfactory. It can also avoid the risk of cartilage damage caused by intra-articular injection. However, the postoperative analgesic effect and timeliness still need to be improved. It is possible to consider combining multimodal mixed drug LIA (combined with intra-articular and periarticular) with other pain intervention methods to exert a synergistic effect, in order to avoid the side effects and risks brought by single drugs or single administration route. LIA is expected to become one of the most common methods for relieving postoperative early pain in ACLR.

Conclusion

Early pain after arthroscopic ACLR still affects the further functional activities of patients, and all kinds of analgesic methods can achieve certain effectiveness, but there is no unified standard at present, and the advantages and disadvantages of various analgesic methods need further research.

Comparative Assessment of Short-Term Tendon-Scleral Postoperative Inflammation and α-Smooth Muscle Actin Expression following Oral and Topical Diclofenac Administration for Strabismus Surgery in Rabbits

PURPOSE

Wound healing and fibrosis modulation are considered pivotal for the long-term outcome of strabismus surgery. Nonsteroidal anti-inflammatory drugs, including diclofenac sodium, are inflammation suppressive drugs that may modulate wound healing, including postoperative inflammation. This study aimed to compare the effect of oral and 0.1% topical diclofenac sodium on short-term inflammation and α-smooth muscle actin (α-SMA) expression at the tendon-scleral attachment site following strabismus surgery in an experimental rabbit model.

METHODS

Superior rectus recession was performed in 12 eyes of six New Zealand rabbits. Rabbits were divided into three groups: oral diclofenac 2 × 5 mg/kg for three days (group A), 0.1% diclofenac sodium eye drops 3 times/day for three days (group B), and controls (group C). On postoperative day 14, enucleation was performed. Macroscopic adhesion score, microscopic adhesion score, percentage of postoperative inflammation area (Masson's trichrome staining), and α-SMA (immunohistochemistry staining) were assessed. Data analysis was performed using a semi-quantitative and quantitative assessment with ImageJ. All groups were compared with reciprocal staining intensity (RSI) values to measure α-SMA expression.

RESULTS

All groups showed no difference in macroscopic (p = 0.13) and microscopic adhesion scores (p = 0.28). The percentage of postoperative inflammation area in group B (12.44% (8.63-18.29)) was significantly lower than group A (26.76% (21.38-37.56) p = 0.03) and group C (27.80% (16.42-36.28), p = 0.04). Comparative RSI analysis found that group B had a significantly lower α-SMA expression than group C (174.08 ± 21.78 vs 212.58 ± 12.06, p = 0.04).

CONCLUSION

The results suggest that compared to oral, the administration of topical diclofenac showed a more significant reduction of short-term postoperative inflammation and α-SMA expression at the tendon-scleral attachment site following strabismus surgery.

Comparing the Efficacy of Postoperative Pain Control Between Intravenous Parecoxib and Oral Diclofenac in ACL Reconstruction

Background:

A nonsteroidal anti-inflammatory drug such as oral diclofenac is normally used to relieve postoperative pain after anterior cruciate ligament reconstruction (ACLR), but most patients continue to have moderate-to-severe pain that disturbs their rehabilitation. Some orthopaedists prefer to use intravenous (IV) parecoxib for postoperative pain control.

Purpose:

To compare the efficacy of IV parecoxib and oral diclofenac for postoperative pain control in ACLR.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

We retrospectively collected and analyzed postoperative pain in patients who underwent both single- and double-bundle ACLR; pain was reported on a 10-point visual analog scale (VAS; 10 = worst pain). After the operation, each patient was given either IV parecoxib twice a day or oral diclofenac 3 times a day, and all patients received paracetamol 6 times per day for 24 hours postoperatively. If the patient complained of moderate or severe pain (VAS >3) after surgery, 3 mg of morphine would be given intravenously every 3 hours and 1 mg of morphine as a rescue analgesic every 1 hour for 24 hours postoperatively. Postoperative VAS and morphine consumption were recorded every 4 hours for 24 hours. Data were analyzed using paired t test, analysis of variance, and chi-square test.

Results:

Overall, 161 patients were included in this study, of whom 47 received IV parecoxib and 114 received oral diclofenac. The mean VAS scores at 4 and 8 hours postoperatively were 3.5 and 3.4, respectively, in the parecoxib group, and 4.4 and 4.7, respectively, in the diclofenac group. The parecoxib group had significantly lower mean VAS than the diclofenac group at 4 hours (P = .047) and 8 hours (P = .005), and the mean cumulative morphine consumption in the parecoxib group was significantly lower than in the diclofenac group at all time points (P < .05) except 4 hours postoperatively.

Conclusion:

This study found that IV parecoxib was more effective than oral diclofenac in controlling postoperative pain and resulted in lower postoperative morphine consumption within the first 24 hours after ACLR.

High-fat diet, adipokines and low-grade inflammation are associated with disrupted tendon healing: a systematic review of preclinical studies

BACKGROUND

The aetiopathogenesis of tendinopathy is uncertain, but inflammation may play a role in the early phase of tendinopathy and in tendon healing response. We investigated the most up-to-date evidence about the association between obesity, high-fat diet and tendinopathy, focusing on the role of adipokines, inflammatory pathways and molecular changes.

SOURCES OF DATA

A systematic review was performed searching PubMed, Embase and Cochrane Library databases following the PRISMA guidelines. We included studies of any level of evidence published in peer-reviewed journals. The risk of bias (SIRCLE) was assessed, as was the methodological quality (CAMARADES) of the included studies. We excluded all the articles with a high risk of bias and/or low quality after the assessment. After applying the inclusion and exclusion criteria, we included 14 studies of medium or high quality.

AREAS OF AGREEMENT

A high-fat diet negatively affects tendon quality, increasing the risk of rupture and tendinopathy.

AREAS OF CONTROVERSY

Controversial evidence exists on both tendon fat infiltration secondary to a dysregulation of the lipid metabolism and of a molecular effect of inflammatory pathways.

GROWING POINTS

The secretion of adipokines is strictly related to fat ingestion and body composition and can potentially act on tendon physiology and injury.

AREAS TIMELY FOR DEVELOPING RESEARCH

Adipokines, low-grade inflammation and fat intake play a role in disrupting tendon healing and setting up tendinopathy. Further high-quality research is needed to better define the molecular pathways involved.

Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) and Their Effect on Musculoskeletal Soft-Tissue Healing: A Scoping Review

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) are being increasingly employed as a part of multimodal non-opioid strategies to treat postoperative pain. In the present study, we sought to review the effects of short-term NSAID use on musculoskeletal soft-tissue healing.

METHODS

We performed a scoping review of all studies that included the use of NSAIDs and their effect on healing of soft tissues, which for the purpose of this review refers to non-osseous musculoskeletal tissue such as ligament, tendon, labrum, and meniscus. The inclusion criteria encompassed all studies (human, animal, and in vitro) that evaluated the effect of NSAIDs on soft-tissue healing. Subgroup analyses, wherever applicable, were conducted on the basis of the type of NSAID (cyclooxygenase [COX]-specific or nonspecific) and the type of study (human, animal, or in vitro). Relevant metadata from each study were abstracted, and descriptive statistics were used to summarize the results.

RESULTS

A total of 44 studies met the inclusion criteria, including 3 human studies, 33 animal studies, and 8 in vitro studies. These studies included 4 different NSAIDs in the human subgroup, 16 different NSAIDs in the animal subgroup, and 7 different NSAIDs in the in vitro subgroup. The majority of reported studies (including 1 of 2 human studies, 10 of 14 animal studies, and 3 of 3 in vitro studies) demonstrated that COX-2-selective inhibitors had negative impact on soft-tissue healing. In contrast, the majority of human and animal studies (2 of 2 and 19 of 30, respectively) demonstrated that nonselective COX inhibitors had no negative effect on the healing of labrum, tendons, and ligaments. The majority of in vitro studies demonstrated that NSAIDs have a harmful effect on biological processes involved in tendon-healing and regeneration (tenocyte proliferation, collagen and glycosaminoglycan synthesis).

CONCLUSIONS

Current limited evidence demonstrates that selective COX-2 inhibitors can negatively affect healing of musculoskeletal soft tissue after surgical repair. In contrast, the majority of studies demonstrate that nonselective COX inhibitors have no negative effect on musculoskeletal soft-tissue healing. Additional high-quality human clinical trials are necessary to provide more definitive conclusions.

Parecoxib exhibits anti-inflammatory and neuroprotective effects in a rat model of transient global cerebral ischemia

Transient global cerebral ischemia (tGCI) induces inflammation leading to secondary brain injury. Data suggested that cyclooxygenase-2 (COX-2) is involved in the occurrence and development of inflammatory reaction after reperfusion; however, the effectiveness of a highly selective COX-2 inhibitor, parecoxib, to counteract tGCI remains to be determined. Thus, the aim of this study was to investigate the potential protective actions of parecoxib in a rat model of tGCI and the role inflammation plays in this disorder. Adult male Sprague-Dawley rats were administered parecoxib 10 or 20 mg/kg intraperitoneally (ip) at 5 min, 24 or 48 hr after tGCI. Control rats received an equal volume of 0.9% saline. The rat model of tGCI was established using the method of bilateral common carotid artery occlusion combined with arterial hypotension. The following parameters were measured: Neurological Severity Score, morphological changes in the hippocampal CA1 region, Evans blue (EB) extravasation, brain water content, levels of matrix metalloproteinase-9 (MMP-9), zonula occludens-1 (ZO-1), neuronal apoptosis, the protein expression of Bcl-2, Bax, COX-2, prostaglandin E2 (PGE₂), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α). Parecoxib treatment significantly improved neurological function and morphological defects in the hippocampal CA1 region, reduced levels of COX-2, PGE₂, IL-1β, and TNF-α. In addition, parecoxib attenuated brain edema and BBB destruction as evidenced by increased ZO-1 expression and decreased MMP-9 expression. Further, parecoxib reduced neuronal apoptosis via diminished protein expression of Bax and enhanced expression of Bcl-2.

Do Nonsteroidal Anti-Inflammatory Drugs Affect Tissue Healing After Arthroscopic Anterior Cruciate Ligament Reconstruction?

Background

Experimental studies have reported nonsteroidal anti-inflammatory drugs (NSAIDs) could impair tendon healing. The purpose of this study was to investigate whether NSAIDs could affect recovery of knee joint function in patients after anterior cruciate ligament (ACL) reconstruction.

Material/Methods

We enrolled 40 patients treated with celecoxib and 40 patients treated with tramadol, who underwent ACL reconstruction from January 2011 to December 2017. Visual analogue scale (VAS) and functional outcomes were collected and evaluated. The follow-up period was 12 months.

Results

In both groups, all patients obtained pain release after surgery, compared with that before surgery. But no significant differences were observed between the 2 groups in VAS scores. We also did not find any differences between the 2 groups at 1 year of follow-up, in terms of anterior drawer test, Lachman test, side-to-side laxity assessed by KT-2000, IKDC score, Lysholm score, and Tegner scale. However, the celecoxib group showed a reduced incidence of nausea compared to the tramadol group (P=0.048).

Conclusions

The use of NSAIDs after ACL reconstruction is relatively safe and could decrease adverse side effects which were caused by opioid drugs.

Localized delivery of miRNAs targets cyclooxygenases and reduces flexor tendon adhesions

The formation of adhesions during healing of an injured tendon remains a difficult problem in clinical practice. Local anti-inflammation gene delivery provides high local gene concentration, reduces the inflammatory response of the injured tendon microenvironment, and decreases systemic side effects to enhance in vivo efficacy. In this study, we designed a novel local sustained gene delivery system by using cyclooxygenase (COX-1 and COX-2)-engineered miRNA plasmid/nanoparticles embedded in hyaluronic acid (HA) hydrogel to reduce flexor tendon adhesions. The local sustained gene delivery system significantly downregulates COX-1 and COX-2 expression in the tendon tissue and the surrounding subcutaneous tissue. More importantly, this plasmid/nanoparticle hydrogel system significantly reduced tissue adhesion formation. This approach offers an effective therapeutic strategy to reduce tendon adhesions by directly targeting the down-regulation of COX-1 and COX-2 expression within the microenvironment of the injured tendon.

STATEMENT OF SIGNIFICANCE

A local sustained gene delivery system was developed to regulate the expression of targeted genes in the specific time and location for tendon adhesion treatment. The engineered miRNA plasmid/nanoparticles embedded in hyaluronic acid hydrogel were synthesized to downregulate the expression of cyclooxygenases in the tendon tissue during the early stage of tendon healing with inflammatory response. This plasmid/nanoparticle hydrogel system offers an effective therapeutic strategy to attenuate the formation of tendon adhesion through direct downregulation of COX-1 and COX-2 expression within the microenvironment of the injured tendon.