The effect of cyclooxygenase-2 inhibition on analgesia and spinal fusion

The impact of perioperative nonsteroidal anti-inflammatory drugs on the postoperative outcomes of spinal surgery: a meta-analysis of 23 randomized controlled trials

In recent years, nonsteroidal anti-inflammatory drug (NSAIDs), which are considered to affect the prognosis of spinal surgery, have been widely used in perioperative analgesia in spinal surgery, but the relationship between these two factors remains unclear. The purpose of this study was to explore the effect of perioperative use of NSAIDs on the prognosis of patients treated with spinal surgery. We systematically searched PubMed, Embase, and Cochrane Library for relevant articles published on or before July 14, 2023. We used a random-effect model for the meta-analysis to calculate the standardized mean difference (SMD) with a 95% confidence interval (CI). Sensitivity analyses were conducted to analyze stability. A total of 23 randomized clinical trials including 1457 participants met the inclusion criteria. Meta-analysis showed that NSAIDs were significantly associated with postoperative morphine use (mg) (SMD = -0.90, 95% CI -1.12 to -0.68) and postoperative pain (SMD = -0.71, 95% CI -0.85 to -0.58). These results were further confirmed by the trim-and-fill procedure and leave-one-out sensitivity analyses. The current study shows that perioperative use of NSAIDs appears to be an important factor in reducing postoperative pain and morphine use in patients undergoing spinal surgery. However, well-designed, high-quality randomized controlled trials (RCTs) are still required.

Publication retraction in spine surgery: a systematic review

PURPOSE

The number of articles retracted by peer-reviewed journals has increased in recent years. This study systematically reviews retracted publications in the spine surgery literature.

METHODS

A search of PubMed MEDLINE, Ovid EMBASE, Retraction Watch, and the independent websites of 15 spine surgery-related journals from inception to September of 2022 was performed without language restrictions. PRISMA guidelines were followed with title/abstract screening, and full-text screening was conducted independently and in duplicate by two reviewers. Study characteristics and bibliometric information for each publication was extracted.

RESULTS

Of 250 studies collected from the search, 65 met the inclusion criteria. The most common reason for retraction was data error (n = 15, 21.13%), followed by plagiarism (n = 14, 19.72%) and submission to another journal (n = 14, 19.72%). Most studies pertained to degenerative pathologies of the spine (n = 32, 80.00%). Most articles had no indication of retraction in their manuscript (n = 24, 36.92%), while others had a watermark or notice at the beginning of the article. The median number of citations per retracted publication was 10.0 (IQR 3-29), and the median 4-year impact factor of the journals was 5.05 (IQR 3.20-6.50). On multivariable linear regression, the difference in years from publication to retraction (p = 0.0343, β = 6.56, 95% CI 0.50-12.62) and the journal 4-year impact factor (p = 0.0029, β = 7.47, 95% CI 2.66-12.28) were positively associated with the total number of citations per retracted publication. Most articles originated from China (n = 30, 46.15%) followed by the United States (n = 12, 18.46%) and Germany (n = 3, 4.62%). The most common study design was retrospective cohort studies (n = 14, 21.54%).

CONCLUSIONS

The retraction of publications has increased in recent years in spine surgery. Researchers consulting this body of literature should remain vigilant. Institutions and journals should collaborate to increase publication transparency and scientific integrity.

Effects of NSAID use on bone healing: A meta-analysis of retrospective case–control and cohort studies within clinical settings

Introduction

This meta-analysis aims to determine whether non-steroidal anti-inflammatory drug (NSAID) use is significantly associated with adverse bone healing outcomes within clinical settings, including trauma and elective spine settings. It will also explore bone healing outcomes with the type, route, dosage and duration of NSAID exposure and aims to demonstrate the effects of various other confounding factors on bone healing outcomes.

Methods

Electronic databases including MedLine, Embase and Cochrane were searched from January 1975 to December 2017. A distinct analysis of observational long bone and spine studies in adult populations was performed, assessing the effects of NSAID exposure on bone healing. Studies from paediatric population and randomised trials also underwent separate assessment in the synthesis. Meta-analysis was conducted in compliance with QUORUM and PRISMA guidelines.

Results

Quantitative assessment of observational studies suggested a significant risk of bone healing complications with NSAID exposure across each clinical group: long bone (p = 0.0004) and spine (p = 0.02). Analysis of paediatric studies revealed a non-significant association of poor outcomes with NSAID use (p = 0.36), while assessment of randomised trials demonstrated a statistically significant risk of complications following NSAID administration (p = 0.04). Meta-regression further suggested smoking to be a substantial confounder associated with adverse bone healing outcomes (p < 0.00001).

Conclusion

Inclusion of only fair and moderate-quality retrospective cohort and case–control studies in the current synthesis limits the clinical application of its findings and therefore warrants the need for further research. Thus, attempts to conduct high-quality prospective cohort and randomised trials to study the effects of NSAID use on bone healing would be very helpful and will provide a basis for more extensive research in future.

Multimodal Analgesia for Perioperative Management of Patients presenting for Spinal Surgery

Multimodal, non-opioid based analgesia has become the cornerstone of ERAS protocols for effective analgesia after spinal surgery. Opioid side effects, dependence and legislation restricting long term opioid use has led to a resurgence in interest in opioid sparing techniques. The increasing array of multimodal opioid sparing analgesics available for spinal surgery targeting novel receptors, transmitters, and altering epigenetics can help provide an optimal perioperative experience with less opioid side effects and long-term dependence. Epigenetic mechanisms of pain may enhance or suppress gene expression, without altering the genome itself. Such mechanisms are complex, dynamic and responsive to environment. Alterations that occur can affect the pathophysiology of pain management at a DNA level, modifying perceived pain relief. In this review, we provide a brief overview of epigenetics of pain, systemic local anesthetics and neuraxial techniques that continue to remain useful for spinal surgery, neuropathic agents, as well as other common and less common target receptors for a truly multimodal approach to perioperative pain management.

Effects of short- and long-term administration of nonsteroidal anti-inflammatory drugs on osteotomy healing in dogs

OBJECTIVE

To determine the influence of short-term administration of carprofen on bone healing in dogs.

STUDY DESIGN

Randomized controlled experimental study.

ANIMALS

Eighteen purpose-bred sexually mature hound dogs.

METHODS

Tibial osteotomies were performed, and dogs were divided into three groups: no carprofen (n = 6), 2-week administration of carprofen at 2.2 mg/kg twice daily (n = 6), and 8-week administration of carprofen at 2.2 mg/kg twice daily (n = 5). Bone healing was evaluated radiographically at 4 and 8 weeks postoperatively. Postmortem, fracture healing was assessed via biomechanical testing (three-point bending), histological cartilage:callus ratio, and bone mineral density (BMD) with quantitative computed tomography.

RESULTS

No biomechanical difference was detected between dogs that received no carprofen and those that received 2 weeks of carprofen or between those that received 2 weeks vs 8 weeks of carprofen. Stiffness (P = .035) and maximum stress (P = .042) were higher in dogs that received no carprofen than in those that received 8 weeks of carprofen. Radiographic healing did not differ between dogs without carprofen and those with 2-week administration of carprofen (P = .9923). However, tibias of dogs without carprofen and those with 2-week administration of carprofen were more healed compared with those in the 8-week-carprofen group at 4 and 8 weeks after surgery (P = .0011). No treatment effect was detected by cartilage:callus ratio or BMD.

CONCLUSION

Long-term administration of carprofen had a negative effect on bone healing compared with short-term or no administration of carprofen.

CLINICAL SIGNIFICANCE

Nonsteroidal anti-inflammatory drugs should be used cautiously in dogs at risk for delayed bone healing, and administration should be discontinued beyond the perioperative period in dogs with fractures or osteotomies.

Nonsteroidal Anti-Inflammatory Drugs and Bone-Healing: A Systematic Review of Research Quality

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) are often avoided by orthopaedic surgeons because of their possible influence on bone-healing. This belief stems from multiple studies, in particular animal studies, that show delayed bone-healing or nonunions associated with NSAID exposure. The purpose of this review was to critically analyze the quality of published literature that evaluates the impact of NSAIDs on clinical bone-healing.

METHODS

A MEDLINE and Embase search was conducted to identify all articles relating to bone and fracture-healing and the utilization of NSAIDs. All human studies, including review articles, were identified for further analysis. Non-English-language manuscripts and in vitro and animal studies were excluded. A total of twelve clinical articles and twenty-four literature reviews were selected for analysis. The quality of the clinical studies was assessed with a modified Coleman Methodology Score with emphasis on the NSAID utilization. Review articles were analyzed with regard to variability in the cited literature and final conclusions.

RESULTS

The mean modified Coleman Methodology Score (and standard deviation) was significantly lower (p = 0.032) in clinical studies that demonstrated a negative effect of NSAIDs on bone-healing (40.0 ± 14.3 points) compared with those that concluded that NSAIDs were safe (58.8 ± 10.3 points). Review articles also demonstrated substantial variability in the number of cited clinical studies and overall conclusions. There were only two meta-analyses and twenty-two narrative reviews. The mean number (and standard deviation) of clinical studies cited was significantly greater (p = 0.008) for reviews that concluded that NSAIDs were safe (8.0 ± 4.8) compared with those that recommended avoiding them (2.1 ± 2.1). Unanimously, all reviews admitted to the need for prospective randomized controlled trials to help clarify the effects of NSAIDs on bone-healing.

CONCLUSIONS

This systematic literature review highlights the great variability in the interpretation of the literature addressing the impact of NSAIDs on bone-healing. Unfortunately, there is no consensus regarding the safety of NSAIDs following orthopaedic procedures, and future studies should aim for appropriate methodological designs to help to clarify existing discrepancies to improve the quality of care for orthopaedic patients.

CLINICAL RELEVANCE

This systematic review highlights the limitations in the current understanding of the effects of NSAIDs on bone healing. Thus, withholding these medications does not have any proven scientific benefit to patients and may even cause harm by increasing narcotic requirements in cases in which they could be beneficial for pain management. This review should encourage further basic-science and clinical studies to clarify the risks and benefits of anti-inflammatory medications in the postoperative period, with the aim of improving patient outcomes.

Sex differences in innate immunity and its impact on opioid pharmacology

Morphine has been and continues to be one of the most potent and widely used drugs for the treatment of pain. Clinical and animal models investigating sex differences in pain and analgesia demonstrate that morphine is a more potent analgesic in males than in females. In addition to binding to the neuronal μ-opioid receptor, morphine binds to the innate immune receptor toll-like receptor 4 (TLR4), located on glial cells. Activation of glial TLR4 initiates a neuroinflammatory response that directly opposes morphine analgesia. Females of many species have a more active immune system than males; however, few studies have investigated glial cells as a potential mechanism driving sexually dimorphic responses to morphine. This Mini-Review illustrates the involvement of glial cells in key processes underlying observed sex differences in morphine analgesia and suggests that targeting glia may improve current treatment strategies for pain. © 2016 Wiley Periodicals, Inc.

The effect of NSAIDs on spinal fusion: a cross-disciplinary review of biochemical, animal, and human studies

PURPOSE

Non-steroidal anti-inflammatory drugs (NSAIDs) play an important role in postoperative pain management. However, their use in the setting of spine fusion surgery setting has long been a topic of controversy. In this review we examined relevant research, including in vivo, animal, and clinical human studies, with the aim of understanding the effect of NSAIDs on spinal fusion.

STUDY DESIGN/SETTING

Systematic review of study designs of all types from randomized controlled trials and meta-analyses to single-institution retrospective reviews.

METHODS

A search of PubMed and Embase was conducted using the keywords: "spine," "spinal fracture," NSAIDs, anti-inflammatory non-steroidal agents, bone, bone healing, fracture, fracture healing, yielding a total of 110 studies. Other 28 studies were identified by cross-referencing, resulting in total 138 studies.

RESULTS

There is no level I evidence from human studies regarding the use of NSAIDs on spinal fusion rates. The overall tone of the spine literature in the early 2000s was that NSAIDs increased the rate of non-union; however, nearly all human studies published after 2005 suggest that short-term (<2 weeks) postoperative use have no such effect. The dose dependency that is seen with a 2-week postoperative course is not present when NSAIDs are only used for 48 h after surgery.

CONCLUSIONS

NSAID appear to have dose-dependent and duration-dependent effects on fusion rates. The short-term use of low-dose NSAIDs around the time of spinal fusion surgery is reasonable. Spine surgeons can consider the incorporation of NSAIDs into pain control regimens for spinal fusion patients with the goal of improving pain control and reducing the costs and complications associated with opioids.

The Effect of Gabapentin Plus Celecoxib on Pain and Associated Complications After Laminectomy

INTRODUCTION

Prevention and treatment of postoperative pain is a major challenge in postoperative care and well-being of the surgical patient. The multimodal analgesic method has been recommended as an alternative treatment for the management of postoperative pain.

AIM

To assess the comparative effect of gabapentin versus gabapentin plus celecoxib on pain and associated complications after laminectomy.

MATERIALS AND METHODS

In this randomized double- blind clinical trial, 114 patients scheduled for elective laminectomy received gabapentin (n=38, 900 mg daily), gabapentin plus celecoxib (n=38, 200 mg celecoxib plus 300mg gabapentin twice a day), and placebo (n=38, capsule containing starch). Visual Analog Scale (VAS) was used to determine the severity of pain. Complications after surgery, anxiety scores before surgery and patient's satisfaction 24 hour after surgery were recorded.

RESULTS

The mean pain sevenity score and morphine consumption in the gabapentin plus celecoxib group were less compared to the placebo and gabapentin group respectively at various intervals (p < 0.001). The mean anxiety score, shivering, nausea, vomiting and pruritus in the gabapentin group were significantly lower compared to the placebo and gabapentin plus celecoxib groups respectively (p < 0.001, p < 0.05). The frequencies of drowsiness (42.1%) in the gabapentin group were significantly high compared to the placebo and gabapentin plus celecoxib group respectively (p <0.001, p< 0.05). In the gabapentin plus celecoxib group patient satisfaction was significantly higher compared to the placebo and gabapentin group (p< 0.05).

CONCLUSION

Combination of 300 mg gabapentin plus 200 mg celecoxib twice a day is a good alternative in multimodal analgesia, effective in pain control with lesser side effects seen with gabapentin alone.

Preemptive multimodal analgesia for postoperative pain management after lumbar fusion surgery: a randomized controlled trial

PURPOSE

To assess the efficacy of a novel preemptive multimodal analgesic regimen for reducing postoperative pain and complications after primary lumbar fusion surgery. Preemptive multimodal analgesia is revealed to be an effective alternative to conventional morphine administration providing improved postoperative pain control with diminished side effects. However, an optimal regimen for spinal fusion surgery remains unknown.

METHODS

After Institutional Review Board approval, 80 patients who underwent primary lumbar 4-5 fusion surgery were randomly assigned to receive either only intravenous morphine or a preemptive multimodal (celecoxib, pregabalin, extended-release oxycodone, and acetaminophen) analgesic regimen. Postoperative pain and functional levels were measured by the visual analog scale (VAS) and Oswestry Disability Index (ODI), respectively, and intraoperative blood loss, postoperative Hemovac drain output, and nonunion rates were evaluated for complications.

RESULTS

No differences were observed in the patient demographics, intraoperative blood loss, postoperative Hemovac drain output, or nonunion rate between two groups. The VAS and ODI were lower at all postoperative time points, except the ODI on postoperative day 1 in patients randomized to receive the preemptive multimodal analgesic regimen. No major identifiable postoperative complications were observed in either treatment group.

CONCLUSIONS

The preemptive multimodal analgesic combination in this study appears to be safe and effective after lumbar fusion surgery.

Pain management following spinal surgeries: An appraisal of the available options

Spinal procedures are generally associated with intense pain in the postoperative period, especially for the initial few days. Adequate pain management in this period has been seen to correlate well with improved functional outcome, early ambulation, early discharge, and preventing the development of chronic pain. A diverse array of pharmacological options exists for the effective amelioration of post spinal surgery pain. Each of these drugs possesses inherent advantages and disadvantages which restricts their universal applicability. Therefore, combination therapy or multimodal analgesia for proper control of pain appears as the best approach in this regard. The current manuscript discussed the pathophysiology of postsurgical pain including its nature, the various tools for assessment, and the various pharmacological agents (both conventional and upcoming) available at our disposal to respond to post spinal surgery pain.

Efficacy of celecoxib for acute pain management following total hip arthroplasty in elderly patients: A prospective, randomized, placebo-control trial

The aim of the present study was to determine whether celecoxib is able to ameliorate pain intensity, provide a narcotic-sparing effect, achieve early ambulation and improve rehabilitation following total hip arthroplasty (THA) in elderly patients. Peri- and post-operative oral celecoxib was administered to verify the efficacy of celecoxib for acute pain management in a multimodal analgesic strategy. All 64 eligible patients were randomly allocated to either the celecoxib group, who took an oral 400 mg capsule of celecoxib peri-operatively and 200 mg per 12 h post-operatively for the first 5 days, or the control group, who were orally treated with a placebo capsule having the same appearance. A multimodal analgesic technique was used in which oral celecoxib or placebo capsule was combined with intravenous patient-controlled analgesia (PCA) morphine pump for peri- and post-operative pain management. Pain assessments were recorded at 6, 12, 24, 48 and 72 h, and 7 and 14 days after THA using the visual analog scale (VAS). PCA morphine consumption; 6, 12, 24 and 48-h post-operative Harris hip score (HHS); time interval until initial ambulation; rates of urinary retention and post-operative nausea and vomiting (PONV) within 72 h; and intra- and post-operative blood loss were also documented. The celecoxib and control groups comprised 34 and 30 patients, respectively. Baseline demographics were comparable between the two groups. The post-operative VAS in the celecoxib group was significantly lower than that in the control group at 12, 24, 48 and 72 h after THA. The post-operative HHS had no significant difference between the two groups, while the time interval until initial ambulation in the celecoxib group (4.5±1.2 days) was significantly less than that in the control group (5.83±2.04 days; P<0.05). Morphine consumption was significantly decreased in the celecoxib group when compared with the control group at 6, 12, 24 and 24 h. Although the 72-h post-operative rates of urinary retention and PONV were lower in the celecoxib group than in the control group, there were no significant differences in these rates between the two groups. The intra- or post-operative blood loss was not significantly different between groups. In conclusion, pre-and post-operative oral celecoxib in a multimodal analgesic strategy can achieve favorable pain relief, reduce opioid consumption, and provide earlier ambulation and improved rehabilitation when compared with PCA morphine alone following THA in elderly patients.

Perioperative pain management in the neurosurgical patient

Perioperative pain management in neurosurgical patients has been inadequately recognized and treated. An increased awareness of pain management and advances in understanding of pain modulation and pathophysiology have led to improved perioperative care of patients. There is a need to assess neurologic function while providing superior analgesia with minimal side effects. Several classes of drugs are currently available or under investigation for use as adjuvants or alternative therapies. There remains a need to determine the best treatment of perioperative pain in this patient population. Improved awareness, assessment, and treatment of pain result in better care and overall patient outcome.

Retracted publications in the drug literature

Recent studies have suggested an increase in the number of retracted scientific publications. It is unclear how broadly the issue of misleading and fraudulent publications pertains to retractions of drug therapy studies. Therefore, we sought to determine the trends and factors associated with retracted publications in drug therapy literature. A PubMed search was conducted to identify retracted drug therapy articles published from 2000-2011. Articles were grouped according to reason for retraction, which was classified as scientific misconduct or error. Scientific misconduct was further divided into data fabrication, data falsification, questions of data veracity, unethical author conduct, and plagiarism. Error was defined as duplicate publication, scientific mistake, journal error, or unstated reasons. Additional data were extracted from the retracted articles, including type of article, funding source, author information, therapeutic area, and retraction issue. A total of 742 retractions were identified from 2000-2011 in the general biomedical literature, and 102 drug studies met our inclusion criteria. Of these, 73 articles (72%) were retracted for a reason classified as scientific misconduct, whereas 29 articles (28%) were retracted for error. Among the 73 articles classified as scientific misconduct, those classified as unethical author conduct (32 articles [44%]) and data fabrication (24 articles [33%]) constituted the majority. The median time from publication of the original article to retraction was 31 months (range 1-130). Fifty percent of retracted articles did not state a funding source, whereas pharmaceutical manufacturer funding accounted for only 13 articles (13%) analyzed. Many retractions were due to repeat offenses by a small number of authors, with nearly 40% of the retracted studies associated with two individuals. We found that a greater proportion of drug therapy articles were retracted for reasons of misconduct and fraud compared with other biomedical studies. It is important for health care practitioners to monitor the literature for retractions so that recommendations for drug therapy and patient management may be modified accordingly.

NSAIDS inhibit in vitro MSC chondrogenesis but not osteogenesis: implications for mechanism of bone formation inhibition in man

The non-steroidal anti-inflammatory drugs (NSAIDs) are widely used for analgesia but may inhibit bone formation. We investigated whether the reported NSAID effect on bone is related to inhibition of bone marrow mesenchymal stem cell (MSC) proliferation and osteogenic and chondrogenic differentiation and evaluated both cyclooxygenase (COX)-1 and COX-2 specific drugs. The effects of seven COX-1 and COX-2 inhibitors on MSC proliferation and osteogenic and chondrogenic differentiation were tested using Vybrant, sodium 3'-[1-(phenylaminocarbonyl)- 3,4-tetrazolium]-bis (4-methoxy-6-nitro) benzene sulfonic acid hydrate (XTT), functional and quantitative assays of MSC differentiation. The MSC expression of COX-1 and COX-2 and prostaglandin E2 (PGE-2) levels were evaluated serially during lineage differentiation by quantitative PCR and ELISA. None of the NSAIDs at broad range of concentration (range 10(-3) to 100 μg/ml) significantly affected MSC proliferation. Surprisingly, MSC osteogenic differentiation inhibition was not evident. However, NSAIDs affected chondrogenic potential with a reduction in sulphated glycosaminoglycans (sGAG) content by 45% and 55% with diclofenac and ketorolac, respectively (P < 0.05 compared to controls). Parecoxib and meloxicam, more COX-2 specific reagents inhibited sGAG to a lesser degree, 22% and 27% respectively (P < 0.05 compared to controls). Cartilage pellet immunohistochemistry confirmed the above results. Pellet chondrogenesis was associated with increased COX-1 expression levels but not COX-2, and COX-1 specific drugs suppressed MSC PGE-2 more than COX-2 specific inhibitors. These findings suggest that NSAIDs may inhibit bone formation via blockage of MSC chondrogenic differentiation which is an important intermediate phase in normal endochondral bone formation.

High-dose ketorolac affects adult spinal fusion: a meta-analysis of the effect of perioperative nonsteroidal anti-inflammatory drugs on spinal fusion

STUDY DESIGN

Meta-analysis of literature.

OBJECTIVE

To evaluate the effect of perioperative nonsteroidal anti-inflammatory drugs (NSAIDs) on the success rate of adult spinal fusion.

SUMMARY OF BACKGROUND DATA

NSAIDs are commonly used to treat postsurgical orthopedic pain. Studies on animal models have shown a significant inhibiting effect of NSAIDs on osteogenesis process, on which spinal fusion also depends. Recently, great interest has been shown in the effect of NSAIDs on the success rate of adult spinal fusion. Clinical trials have tested the effect of perioperative NSAIDs in spinal fusion procedures. A cumulative result of these studies would give more credit to the final conclusions.

METHODS

A systematic search of electronic databases and references from eligible articles was conducted. Comparative studies reporting on the results of primary spinal fusion including treatment group of NSAIDs perioperatively were regarded eligible. A pooled estimate of effect size was produced using both random and fixed effect model.

RESULTS

Five retrospective comparative studies (n = 1403 participants) were included in the present study. The mean age of these patients was more than 40 years and none of them had NSAIDs for longer than 14 days following spinal fusion surgery. High-dose ketorolac showed a statistically significant adverse effect on spinal fusion (P = 0.001, RR = 2.87, 95% CI = 1.53 = - 5.38) with no statistical heterogeneity (I = 3%, P = 0.38), whereas normal-dose NSAIDs (ketorolac, diclofenac sodium, celecoxib, or rofecoxib) did not appear to produce inferior results than the no-NSAIDs group (P = 0.30, RR = 1.39, 95% CI = 0.74 - 2.61) with no statistical heterogeneity (I² = 0%, P = 0.50).

CONCLUSION

Although randomized controlled trials would be optimal for meta-analyses, the data of this review revealed that short-time (<14 days) exposure to normal-dose NSAIDs (ketorolac, diclofenac sodium, celecoxib, or rofecoxib) were safe after spinal fusion, whereas short-time (<14 days) exposure to high-dose ketorolac increased the risk of nonunion, which meant that the effect of perioperative NSAIDs on spinal fusion might be dose-dependent. Further studies would be needed to find out whether long-time exposure to normal-dose NSAIDs could also increase the risk of nonunion and which type of NSAIDs would like to have a worse effect on spinal fusion.

NSAID exposure and risk of nonunion: a meta-analysis of case-control and cohort studies

Nonsteroidal anti-inflammatory drugs (NSAIDs) are frequently used for postoperative pain control. However, concerns regarding the potential deleterious effects of NSAIDs on bone healing have compelled many physicians to avoid NSAIDs in patients with healing fractures, osteotomies, and fusions. We systematically reviewed and analyzed the best clinical evidence regarding the effects of NSAID exposure on bone healing. Medline, Embase, and Cochrane electronic databases were searched for prospective and retrospective clinical studies of fracture, osteotomy, and fusion studies of patients with NSAID exposure and nonunion as an outcome. Study quality was assessed using the Newcastle-Ottawa Scale. Data on study design, patient characteristics, and risk estimates were extracted. Pooled effect estimates were calculated. Subanalyses were performed by bone type and by NSAID dose, duration, and route of administration. In the initial analysis of 11 cohort and case-control studies, the pooled odds ratio for nonunion with NSAID exposure was 3.0 (95% confidence interval 1.6-5.6). A significant association between lower-quality studies and higher reported odds ratios for nonunion was observed. When only higher-quality studies were considered, seven spine fusion studies were analyzed, and no statistically significant association between NSAID exposure and nonunion was identified (odds ratio = 2.2, 95% confidence interval 0.8-6.3). There was no increased risk of nonunion with NSAID exposure when only the highest-quality studies were assessed. Randomized controlled trials assessing NSAID exposure in fracture, fusion, and osteotomy populations are warranted to confirm or refute the findings of this meta-analysis of observational studies.

[What can we learn from the Scott Reuben case? Scientific misconduct in anaesthesiology]

In February 2009 a major case of scientific misconduct was discovered. The American pain researcher Dr. S. Reuben had published 21 papers over a period of 15 years that were found to be fraudulent. Suddenly many advances in postoperative pain therapy which had been assumed to be correct seemed questionable. In this review article the lessons which can be learnt from this case are described. This review also reveals that it is almost impossible for reviewers or readers of scientific journals to detect scientific fraud. However, several warning signs can be identified that might be useful when reading clinical papers. In retrospect many of these signs were detectable in Reuben's studies. Based on the fraudulent papers of Reuben it will be shown how and to what extent falsified results can affect other types of literature, such as practice guidelines, meta-analyses, review articles and oral presentations.

[Fraudulent pain research: a hurt so deep nothing can alleviate it]

Untruthfulness in research is reprehensible. Dr Scott S. Reuben, an anesthesiologist at Baystate Medical Center in Springfield, Massachusetts in the United States, a leader and pioneer in the field of multimodal analgesia, has been accused of fraud, specifically of having falsified results in at least 21 manuscripts published over a period of 15 years. This may come to be seen as one of the largest-scale and longest-running acts of medical research fraud ever. Apart from fabricated data, it seems the author committed other acts of misconduct. His coauthors have not been accused of wrongdoing, as they allege their names were falsely appended to the manuscript. The editors of the 2 most implicated journals, Anesthesiology and Anesthesia & Analgesia, have published editorials retracting the papers they judge to be fraudulent. Because Dr Reuben is a major figure in postoperative multimodal analgesia, many studies by other authors whose hypotheses have emerged from findings announced in the discredited papers may also now be considered contaminated by association. The definitions of scientific misconduct and the procedures for pursuing offenders vary greatly from country to country, creating a certain degree of uncertainty about how to proceed when we confront this problem. Beyond any possible legal liability that might arise, there are the questions of how fraud might affect patients' health or the medical knowledge base. Although the concept of multimodal analgesia may continue to be defended, we cannot be absolutely sure of its benefits without carrying out new clinical trials to repair the damage done by this act of misconduct.

The use of NSAIDs in pediatric scoliosis surgery - a survey of physicians' prescribing practice

BACKGROUND

Pediatric scoliosis surgery is associated with considerable postoperative pain requiring opioids for analgesia. Nonsteroidal antiinflammatory drugs (NSAIDs) can be used as adjuvants for analgesia; however, the potential of these agents to affect bone healing raises concerns. No large-scale prospective studies have been performed to evaluate the benefit-to-risk ratio of NSAID use after pediatric scoliosis surgery. Given the lack of evidence in the literature, a survey of practice patterns of anesthesiologists from around the world was conducted with respect to the use of NSAIDs after pediatric spinal fusion surgery for scoliosis.

METHODS

One hundred and fourteen anesthesiologists from international academic pediatric hospitals were asked to complete an online survey. After 1 month, nonresponders were sent a second e-mail asking for their participation. All questions were developed specifically for this study.

RESULTS

Out of 80 anesthesiologists who responded 61 were included in the final analysis. Fifty-nine percent routinely use NSAIDs, the most common agents being intravenous ketorolac and oral ibuprofen. The majority of respondents begin to administer NSAIDs within the first three postoperative days for a duration of four or more days. The primary reason for not routinely prescribing NSAIDs was the risk of bone nonunion.

CONCLUSIONS

This survey demonstrates that the practice patterns of pediatric anesthesiologists from around the world with respect to the administration of NSAIDs for the management of postoperative pain after pediatric spinal fusion reflects the conflicting evidence in the literature and the lack of high-quality studies in humans.

Dose-dependent inhibition of diclofenac sodium on posterior lumbar interbody fusion rates

BACKGROUND CONTEXT

The use of nonsteroidal anti-inflammatory drugs (NSAIDs) had been implicated as a risk factor for nonunion in spinal fusion. Even with a number of animal and human studies suggesting NSAIDs either delay or inhibit spinal fusion rates, these drugs continue to be used because of demonstrated benefits. Diclofenac sodium is no exception. It is very popular as a first-line treatment for acute pain, even perioperatively for spine fusion patients. Review of published literature reveals no studies done on the effect of diclofenac sodium on spine fusion rates.

PURPOSE

To determine if diclofenac sodium is a risk factor for delayed union and nonunion in adult patients who underwent one- to two-level instrumented posterior lumbar interbody fusion (PLIF) using only local autogenous bone graft.

STUDY DESIGN/SETTING

Retrospective, analytical.

PATIENT SAMPLE

Two hundred and seventy-three adult patients who underwent one- to two-level PLIF with minimum 2-year follow-up.

OUTCOME MEASURES

Diclofenac sodium intake, fusion status.

METHODS

Medical records and radiographs of 273 adult patients who underwent one- to two-level PLIF in a single institution from 1999 to 2004 were reviewed. All patients did not use any NSAID or steroid perioperatively, except for diclofenac sodium postoperatively. The amount of diclofenac sodium used was quantified for the first 14 days post-op. These patients were followed-up periodically for 2 years. Demographic data, levels fused, and NSAID intake were correlated to union status.

RESULTS

Nineteen out of the 273 patients had no diclofenac sodium intake (no-dose group), 168 patients used less than or equal to 300 mg (moderate-dose group), and 86 patients used more than 300 mg of diclofenac sodium (high-dose group). There were 4 nonunions and 41 delayed unions seen. No significant difference was seen when fusion status was compared with age, sex, L5-S1 versus other levels, and smoking history (all comparisons, p>.05). There was a significant difference between one- and two-level fusions in terms of union status (p=.002). There were no nonunions and 18 delayed unions seen in 217 patients in the single-level fusion group. All 4 nonunions and 23 delayed unions were noted among the 56 patients in the two-level group. There were no cases of delayed union and nonunion in the no-dose group. There were also no nonunions but 16 delayed unions in the moderate-dose group. There were 4 nonunions and 25 delayed unions in the high-dose group. As diclofenac sodium intake increases, the incidence of delayed union and nonunion were also seen to increase (p<.001). Time to union was correlated to the amount of diclofenac sodium intake using Pearson's correlation coefficient (r=0.271, p<.001). When the patients were divided into one- and two-level fusion groups, the amount of diclofenac sodium used still had a significant positive correlation to frequency of delayed union and nonunion and in time to union in each group (all comparisons, p<.05).

CONCLUSIONS

Diclofenac sodium showed a dose-dependent inhibitory effect toward spine fusion especially when used during the immediate postoperative period. No significant correlation was seen between age, sex, L5-S1 versus other levels fused and smoking history when compared with spine nonunion. Two-level lumbar fusions also showed a significant negative correlation to spine fusion compared with single-level fusions.

Selective and nonselective nonsteroidal anti-inflammatory drugs in perianesthesia pain management

Despite advances in pain management techniques, there remains room for further improvement in optimizing postoperative patient comfort. Although nonsteroidal anti-inflammatory drugs (NSAIDs) that are more selective in the inhibition of the cyclooxygenase (COX) enzyme have become more popular over recent years, the use of traditional nonselective NSAIDs remains efficacious in reducing postoperative pain. Both nonselective and selective NSAIDs have an important role in perianesthesia pain management. This article reviews the benefits and risks of both nonselective NSAIDs and COX-2 NSAIDs in the perianesthesia period.

[Pain therapy after spinal surgery]

A dorsal approach during spinal surgery offers the possibility to distribute drugs directly to the nerve root or epidurally. This can be done via a single intraoperative dose or by placing an epidural catheter. A safe and effective analgesia can thereby be achieved. As placement is done under visual control, no major complications are to be expected. In nerve root compressions, additional local application of steroids and preoperative gabapentin seems sensible. No advantage of preemptive administration of other analgesics can be determined. Another problem, especially of ventral fusions, is the commonly needed autologous pelvic bone grafts. Here the local application of local anesthetics or opioids makes sense. In transthoracic approaches epidural analgesia is recommended by thoracic surgeons, but this is difficult to perform especially in children with deformities. Furthermore it is generally important not to compromise neuralgic controls by analgesic measures.

Ketorolac and spinal fusion: does the perioperative use of ketorolac really inhibit spinal fusion?

STUDY DESIGN

Retrospective review.

OBJECTIVE

To evaluate the effect of postoperative use of ketorolac (Toradol) on spinal fusion in humans.

SUMMARY OF BACKGROUND DATA

The value of parenteral ketorolac in postoperative analgesia has been well documented across surgical specialties. However, some studies have shown that ketorolac may adversely affect osteogenic activity and fracture healing.

METHODS

A total of 405 consecutive patients who underwent primary lumbar posterolateral intertransverse process fusion with pedicle screw instrumentation were included in this retrospective study. A subtotal of 228 patients received Toradol after surgery for adjunctive analgesia. Each patient received a mandatory dose of 30 mg intravenously every 6 hours for 48 hours. The same surgeon performed the fusion procedure on all of these patients. Historical controls included 177 patients who did not receive Toradol after surgery. The minimum follow-up period was 24 months. Nonunions were diagnosed by analyzing sequential radiographs, flexion-extension radiographs, and computed tomography with multiplanar reconstructions. The gold standard of surgical exploration was performed in symptomatic patients with diagnostic ambiguity or nonunions diagnosed by imaging.

RESULTS

There were no smokers in the study population. Pseudarthrosis was identified in 12 of 228 patients (5.3%) who received Toradol after surgery, and in 11 of 177 patients (6.2%) who did not. There was no significant difference detected in the nonunion rates between the two groups (P > 0.05, chi2 method).

CONCLUSION

Use of ketorolac after spinal fusion surgery in humans, limited to 48 hours after surgery for adjunctive analgesia, has no significant effect on ultimate fusion rates.

A procedure-specific systematic review and consensus recommendations for postoperative analgesia following total knee arthroplasty

The PROSPECT Working Group, a collaboration of anaesthetists and surgeons, conducts systematic reviews of postoperative pain management for different surgical procedures (http://www.postoppain.org). Evidence-based consensus recommendations for the effective management of postoperative pain are then developed from these systematic reviews, incorporating clinical practice observations, and transferable evidence from other relevant procedures. We present the results of a systematic review of pain and other outcomes following analgesic, anaesthetic and surgical interventions for total knee arthroplasty (TKA). The evidence from this review supports the use of general anaesthesia combined with a femoral nerve block for surgery and postoperative analgesia, or alternatively spinal anaesthesia with local anaesthetic plus spinal morphine. The primary technique, together with cooling and compression techniques, should be supplemented with paracetamol and conventional non-steroidal anti-inflammatory drugs or COX-2-selective inhibitors, plus intravenous strong opioids (high-intensity pain) or weak opioids (moderate- to low-intensity pain).

Clinical pain management peri-operative scenarios

This article reinforces the clinical points of emphasis that have been stressed throughout this issue in a case scenario format. Common situations dealt with by physicians are examined to highlight the underlying physiology of the specific complaints and treatment interventions. The goal of this article is to present an evidenced-based review of pain management interventions in a format that allows for reader incorporation.

Perioperative celecoxib administration for pain management after total knee arthroplasty - a randomized, controlled study

BACKGROUND

Non-steroidal anti-inflammatory drugs (NSAIDs) are recommended for multimodal postoperative pain management. We evaluated opioid-sparing effects and rehabilitative results after perioperative celecoxib administration for total knee arthroplasty.

METHODS

This was a prospective, randomized, observer-blind control study. Eighty patients that underwent total knee arthroplasty were randomized into two groups of 40 each. The study group received a single 400 mg dose of celecoxib, one hour before surgery, and 200 mg of celecoxib every 12 hours for five days, along with patient-controlled analgesic (PCA) morphine. The control group received only PCA morphine for postoperative pain management. Visual analog scale (VAS) pain scores, active range of motion (ROM), total opioid use and postoperative nausea/vomiting were analyzed.

RESULTS

Groups were comparable for age, pre-operative ROM, operation duration and intraoperative blood loss. Resting VAS pain scores improved significantly in the celecoxib group, compared with controls, at 48 hrs (2.13 +/- 1.68 vs. 3.43 +/- 1.50, p = 0.03) and 72 hrs (1.78 +/- 1.66 vs. 3.17 +/- 2.01, p = 0.02) after surgery. Active ROM also increased significantly in the patients that received celecoxib, especially in the first 72 hrs [40.8 degrees +/- 17.3 degrees vs. 25.8 degrees +/- 11.5 degrees , p = 0.01 (day 1); 60.7 degrees +/- 18.1 degrees vs. 45.0 degrees +/- 17.3 degrees , p = 0.004 (day 2); 77.7 degrees +/- 15.1 degrees vs. 64.3 degrees +/- 16.9 degrees , p = 0.004 (day 3)]. Opioid requirements decreased about 40% (p = 0.03) in the celecoxib group. Although patients suffering from post-operative nausea/vomiting decreased from 43% in control group to 28% in celecoxib group, this was not significant (p = 0.57). There were no differences in blood loss (intra- and postoperative) between the groups. Celecoxib resulted in no significant increase in the need for blood transfusions.

CONCLUSION

Perioperative celecoxib significantly improved postoperative resting pain scores at 48 and 72 hrs, opioid consumption, and active ROM in the first three days after total knee arthroplasty, without increasing the risks of bleeding.

TRIAL REGISTRATION

Clinicaltrials.gov NCT00598234.

Pharmacological agents and impairment of fracture healing: what is the evidence?

Bone healing is an extremely complex process which depends on the coordinated action of several cell lineages on a cascade of biological events, and has always been a major medical concern. The use of several drugs such as corticosteroids, chemotherapeutic agents, non-steroidal anti-inflammatory drugs (NSAIDs), antibiotics, anticoagulants and drugs which reduce osteoclastic activity have been shown to affect bone healing. This review article presents our current understanding on this topic, focusing on data illustrating the effect of these drugs on fracture healing and bone regeneration.

Effect of parecoxib on postoperative pain after lumbar spine surgery: a bicenter, randomized, double-blinded, placebo-controlled trial

STUDY DESIGN

A bicenter randomized, patients, healthcare providers, and data collectors blind placebo-controlled trial in multimodal analgesia for postoperative lumbar spine surgery was conducted.

OBJECTIVE

To assess the efficacy and safety of parecoxib on postoperative pain management after posterior lumbar spine surgery.

SUMMARY OF BACKGROUND DATA

Systematic reviews suggest that cyclo-oxygenase-2 inhibitors are an effective treatment for acute postoperative pain. However, previous trials on lumbar spine surgery showed equivocal efficacy of cyclo-oxygenase-2 inhibitors for postoperative pain relief.

METHODS

In this study, 120 patients undergoing posterior lumbar discectomy, spinal decompression, or spinal fusion were stratified based on the surgical procedure to 3 groups (n = 40) and randomly allocated to receive multidoses of parecoxib 40 mg/dose or placebo. Efficacy was assessed by total morphine used from patient-controlled analgesic pump, pain intensity, pain relief, and the patient's subjective rating of the medication.

RESULTS

Parecoxib 40 mg reduced the total amount of morphine required over 48 hours by 39% relative morphine reduction compared with placebo (P = 0.0001). Pain at rest was reduced by 30% (P = 0.0001). Ninety percent of patients given parecoxib experienced at least 50% maximum total pain relief compared with 58% treated with placebo. The number-needed-to-treat for 1 patient to have at least half pain relief was 3.1 (2.0-4.6). Patients' subjective rating of the medication was described as "excellent, good, and fair" by 48%, 43%, and 8% in the parecoxib group, respectively, compared with 21%, 50%, and 28% of placebo patients (P = 0.004). Overall adverse effects of patients receiving parecoxib and morphine were comparable to those receiving morphine alone.

CONCLUSION

The present study demonstrates that the perioperative administration of parecoxib with patient-controlled analgesic morphine after lumber spine surgery resulted in significantly improved postoperative analgesic management as defined by reduction in opioid requirement, lower pain scores, and higher patients' subjective rating of the medication.

Non-steroidal anti-inflammatory drugs, cyclooxygenase-2 and the bone healing process

Traditional non-steroidal anti-inflammatory drugs (NSAID) and selective cyclooxygenase-2 (COX-2) inhibitors are widely used in the treatment of pain, including bone fracture pain and orthopaedic post-operative pain. The gastrointestinal and cardiovascular adverse effects of NSAIDs are acknowledged, but their effects on bone are less widely known. Prostaglandins play an important role in the regulation of osteoblast and osteoclast functions, and inhibition of prostaglandin production retards bone formation. Therefore, NSAIDs could be expected to have significant consequences in divergent clinical situations where bone formation or remodelling is a contributing factor. The present survey reviews current experimental and clinical evidence related to two of those conditions (i.e. on ectopic bone formation and on bone fracture healing). NSAIDs are used clinically to prevent ectopic bone formation (also known as heterotopic ossification) (e.g. after total hip arthroplasty or trauma). The efficacy of NSAIDs in the avoidance of heterotopic ossification has been documented in controlled clinical trials, but the inherent risks (e.g. on healing processes and on loosening of prostheses) need further studies. At the same time, NSAIDs are widely used in the treatment of fracture pain, and their inhibitory effects on the ongoing bone healing process have raised concerns. Results of fracture healing studies in animals treated with NSAIDs or in mice lacking COX-2 gene show that inhibition or deficiency of COX-2 impairs the bone healing process. The limited clinical data also support the assumption that inhibition of COX-2 by non-selective or COX-2-selective NSAIDs delays fracture healing. However, the clinical significance of the effect in various patient groups needs to be carefully assessed and further investigations are needed to characterize the patients at the highest risk for NSAID-induced delayed fracture healing and its complications. In the meantime, use of NSAIDs in fracture patients should be cautious, keeping in mind the benefits of pain relief and inhibition of ectopic bone formation on one hand, and the risks of non-union and retarded union on the other hand.

Inhibition of cyclooxygenase-2 down-regulates osteoclast and osteoblast differentiation and favours adipocyte formation in vitro

Nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit cyclooxygenases (COX) and are widely used for post-trauma musculoskeletal analgesia. In animal models, NSAIDs have been reported to delay fracture healing and cause non-union, possibly due to the drug-induced inhibition of osteoblast recruitment and differentiation. To further investigate the cellular effects of these drugs in the context of bone healing, we examined the effects of COX-1 inhibitor indomethacin and COX-2 inhibitors, parecoxib and NS398 on osteoclast and osteoblast differentiation and activity in vitro. We discovered that all tested COX-inhibitors significantly inhibited osteoclast differentiation, by 93%, 94% and 74% of control for 100 microM indomethacin, 100 microM parecoxib and 3 microM NS398, respectively. Furthermore, inhibition of COX-2 reduced also the resorption activity of mature osteoclasts. All tested COX-inhibitors also significantly inhibited osteoblast differentiation from human mesenchymal stem cells. Simultaneously, the number of adipocytes was significantly increased. The adipocyte covered areas in the cultures with 1 microM indomethacin, 1 microM parecoxib and 3 microM NS398 were 9%, 29% and 24%, respectively, as compared with 6% in the control group. This data suggests that COX-2 inhibition disturbs bone remodelling by inhibiting osteoclast differentiation and diverting stem cell differentiation towards adipocyte lineage instead of osteoblast lineage. In conclusion, our results further suggest cautious use of COX-2 inhibitors after osseous trauma.

Perioperative pain management in the neurosurgical patient

The perioperative management of pain in neurosurgical patients is a controversial topic with management decisions based mainly on reports of anecdotal experiences. There is no consensus regarding the standardization of pain control in this patient population. In the last decade, improved awareness and advances in the practice of pain management have resulted in the implementation of diverse techniques to achieve adequate analgesia in this undertreated group of patients. This article provides information about the various techniques and approaches, based on the latest research and clinical trials conducted in this patient population. Specifically, the physiology of pain in patients undergoing brain or spine surgery, the different modalities for pain control, and the diverse choice of drugs, with their associated risks and benefits, are reviewed.

The effects of medications on bone

Medications taken for the treatment of arthritis and psychotropic and epileptic disorders, as well as anticoagulants, antacids, bisphosphonates, corticosteroids, and antineoplastic drugs, can profoundly affect bone metabolism. In some scenarios (eg, osteoporosis), these effects are intended; in others (eg, rickets, osteomalacia secondary to antiepileptic drugs), potentially adverse side effects of medications on bone may occur. Nonsteroidal anti-inflammatory drugs appear to delay fracture healing and bone ingrowth, although these effects are reversible. Disease-modifying antirheumatic drugs do not appear to affect bone metabolism adversely when taken in the low dosages currently prescribed. Bisphosphonates are useful in restoring bone mass in cases of postmenopausal osteoporosis, glucocorticoid-induced osteoporosis, Paget's disease, and neoplastic conditions with bone loss and hypercalcemia. Corticosteroids and cancer chemotherapeutic agents generally affect bone adversely and increase fracture risk.

Evaluating the Analgesic Efficacy of Administering Celecoxib as a Component of Multimodal Analgesia for Outpatient Anterior Cruciate Ligament Reconstruction Surgery: Retracted

BACKGROUND

Cyclooxygenase-2 inhibitors may play an important role in multimodal management of pain after orthopedic surgery. We examined the analgesic efficacy of administering celecoxib as a component of a multimodal analgesic regimen for outpatient anterior cruciate ligament (ACL) surgery.

METHODS

Two-hundred consecutive patients were randomized to receive acetaminophen 1000 mg and either celecoxib 400 mg or placebo 1-2 h before ACL surgery. All patients received intraarticular analgesics (bupivacaine, clonidine, and morphine) and had an external cooling system applied to the operative knee. After discharge, patients were instructed to take acetaminophen 1000 mg every 6 h and either celecoxib 200 mg every 12 h or matching placebo for the first 14 days postoperatively. Oxycodone 5-10 mg was available for rescue analgesia.

RESULTS

Patients in the celecoxib group were more likely to experience less pain in the recovery room (P < 0.01) and require less opioids (P < 0.001) for postoperative analgesia. These patients reported a lower incidence of postoperative nausea and vomiting (P < 0.05) and were discharged home earlier (P < 0.05). While at home, patients in the celecoxib group reported lower pain scores both at rest (P < 0.05) and with movement (P < 0.01), and used less oxycodone at all postoperative time intervals.

CONCLUSIONS

The perioperative administration of celecoxib decreases postoperative pain, opioid use, postoperative nausea and vomiting, and recovery room length of stay. These results support the use of celecoxib as a component of a preventive multimodal analgesic technique for ACL surgery.

Osteoporosis: pathogenesis, new therapies and surgical implications

Many developments occurred in the realm of bone healing in recent years. Genetic discoveries, new proteins affecting bone health, and new treatments have steered our treatment of traumatic and iatrogenic fractures in new directions. Osteoporosis strikes many subsets of the world population, including: women, the elderly, and those suffering from arthritis, autoimmune diseases, HIV, and the immunocompromised. This disease predisposes people to an increased risk of low trauma and fragility fractures. The baby boomer generation and an increasing lifespan may burden the economy by creating such a large group susceptible to such a potentially devastating disease. The novel treatments and coping with the potentially challenging surgical implications will aide the podiatric physician in both medical and surgical management of osteoporosis.

Update on the role of non-opioids for postoperative pain treatment

Non-opioids play an ever increasing role in the treatment of postoperative pain; either on their own for mild to moderate pain or in combination with other analgesic approaches, in particular opioids, as a component of multimodal analgesia. The analgesics paracetamol (acetaminophen) and dipyrone (metamizole) as well as compounds with an additional anti-inflammatory effect (non-selective non-steroidal anti-inflammatory drugs and selective cyclo-oxygenase-2 inhibitors) are used widely in the perioperative period. Paracetamol is gaining renewed interest in this setting due to its minimal adverse effects and recent availability in a parenteral preparation, but its benefits are insufficiently studied. Dipyrone continues to be used in many countries despite the ongoing debate on the incidence and relevance of its ability to cause agranulocytosis. Among the anti-inflammatory drugs, selective cyclo-oxygenase-2 inhibitors have the most supportive data for their beneficial effects as a component of multimodal analgesia and offer benefits with regard to their adverse effect profile.

Cyclooxygenase-2 inhibition delays the attainment of peak woven bone formation following four-point bending in the rat

Fracture healing is retarded in the presence of cyclooxygenase-2 (COX-2) inhibitors, demonstrating an important role of COX-2 in trauma-induced woven bone adaptation. The aim of this experiment was to determine the influence of COX-2 inhibition on the remodeling and consolidation of nontraumatic woven bone produced by mechanical loading. A periosteal woven bone callus was initiated in the right tibia of female Wistar rats following a single bout of four-point bending, applied as a haversine wave for 300 cycles at a frequency of 2 Hz and a magnitude of 65 N. Daily injections of vehicle (VEH, polyethylene glycol) or the COX-2 inhibitor 5,5-dimethyl-3-3(3 fluorophenyl)-4-(4-methylsulfonal)phenyl-2(5H)-furanone (DFU, 2.0 mg . kg(-1) and 0.02 mg . kg(-1) i.p.), commenced 7 days postloading, and tibiae were examined 2, 3, 4, and 5 weeks postloading. Tibiae were dissected, embedded in polymethylmethacrylate, and sectioned for histomorphometric analysis of periosteal woven bone. No significant difference in peak woven bone area was observed between DFU-treated and VEH rats. However, treatment with DFU resulted in a temporal defect in woven bone formation, where the achievement of peak woven bone area was delayed by 1 week. Woven bone remodeling was observed in DFU-treated rats at 21 days postloading, demonstrating that remodeling of the periosteal callus is not prevented in the presence of a COX-2 inhibitor in the rat. We conclude that COX-2 inhibition does not significantly disrupt the mechanism of woven bone remodeling but alters its timing.