Parecoxib and indomethacin delay early fracture healing: a study in rats

Risk Factors for Dehiscence of Operative Incisions in Newborns after Laparotomy

BACKGROUND

 Surgical wound dehiscence (SWD) in neonates is a life-threatening complication. The aim was to define risk factors of postoperative incision dehiscence in this population.

METHODS

 Data of 144 patients from 2010 to 2020 were analyzed retrospectively. All full-term newborns or preterm newborns up to 42 weeks of amenorrhea (adjusted) who had a laparotomy within 30 days were included. Descriptive patient information and perioperative data were collected. SWD was defined as any separation of cutaneous edges of postoperative wounds.

RESULTS

 Overall, SWD occurred in 16/144 (11%) patients, with a significantly increased incidence in preterm newborns (13/59, 22%) compared with full-term newborns (3/85, 4%; p < 0.001). SWD was significantly associated with exposure to postnatal steroids (60% vs. 4%, p < 0.001) and nonsteroidal anti-inflammatory drugs (25% vs. 4%, p < 0.01), invasive ventilation duration before surgery (median at 10 vs. 0 days, p < 0.001), preoperative low hemoglobin concentration (115 vs. 147 g/L, p < 0.001) and platelet counts (127 vs. 295 G/L, p < 0.001), nonabsorbable suture material (43% vs. 8%, p < 0.001), the presence of ostomies (69% vs. 18%, p < 0.001), positive bacteriological wound cultures (50% vs. 6%, p < 0.001), and relaparotomy (25% vs. 3%, p < 0.01). Thirteen of 16 patients with SWD presented necrotizing enterocolitis/intestinal perforations (81%, p < 0.001).

CONCLUSION

 This study identified prematurity and a number of other factors linked to the child's general condition as risk factors for SWD. Some of these can help physicians recognize and respond to at-risk patients and provide better counseling for parents.

Remotely Temporal Scheduled Macrophage Phenotypic Transition Enables Optimized Immunomodulatory Bone Regeneration

Precise timing of macrophage polarization plays a pivotal role in immunomodulation of tissue regeneration, yet most studies mainly focus on M2 macrophages for their anti-inflammatory and regenerative effects while the essential proinflammatory role of the M1 phenotype on the early inflammation stage is largely underestimated. Herein, a superparamagnetic hydrogel capable of timely controlling macrophage polarization is constructed by grafting superparamagnetic nanoparticles on collagen nanofibers. The magnetic responsive hydrogel network enables efficient polarization of encapsulated macrophage to the M2 phenotype through the podosome/Rho/ROCK mechanical pathway in response to static magnetic field (MF) as needed. Taking advantage of remote accessibility of magnetic field together with the superparamagnetic hydrogels, a temporal engineered M1 to M2 transition course preserving the essential role of M1 at the early stage of tissue healing, as well as enhancing the prohealing effect of M2 at the middle/late stages is established via delayed MF switch. Such precise timing of macrophage polarization matching the regenerative process of injured tissue eventually leads to optimized immunomodulatory bone healing in vivo. Overall, this study offers a remotely time-scheduled approach for macrophage polarization, which enables precise manipulation of inflammation progression during tissue healing.

Non-steroidal anti-inflammatory drugs and bone healing in animal models-a systematic review and meta-analysis

BACKGROUND

Non-steroidal anti-inflammatory drugs (NSAID) have excellent anti-inflammatory and analgesic properties and are extensively used to treat post-traumatic or surgical musculoskeletal pain. Although an extensive literature exists on the administration of NSAID on animal bone healing, no systematic review and meta-analysis of animal studies that investigate the effect of NSAID administration on bone fracture healing. Objective of this study is to conduct a systematic review and meta-analysis to estimate the effect of NSAIDs administration on bone healing biomechanical and histomorphometric measurements in different animal models after bone fracture surgery.

METHODS

We performed a systematic review and meta-analysis of animal studies to estimate the effect of NSAID administration after bone fracture on healing outcomes. We searched eight databases without limiting the search to starting date up to 1 February 2021 for articles on fractured bone healing in animal models in which NSAID were administered.

RESULTS

Out of 6732 articles screened, 47 were included and 3 common bone healing outcomes were analysed: biomechanical properties (maximum force to break, stiffness, and work-to-failure), micro-computed tomography (μ-CT), and histomorphometric measurements. The studies were generally of low-quality scores because crucial information, especially concerning randomization, blinding, and allocation concealment, was poorly reported. Our results show that the negative effects of NSAID after bone fracture on certain biomechanical properties of the healing bones was not statistically significant in mice compared with other animals, in females compared with males, and in younger compared with older animals.

CONCLUSION

The findings demonstrated that NSAIDs administration decreased the biomechanical properties of healing bones after fracture surgery in comparison to the control group. Moreover, different effect on certain outcomes was detected among different sites, sex of the animals, and the time of assessment.

TRIAL REGISTRATION

Protocol published and registered in SYstematic Review Center for Laboratory animal Experimentation (SYRCLE) in 2017, https://www.radboudumc.nl/getmedia/757ec408-7a9e-4635-8233-ae951effea54/Non-Steroidal-Anti-inflammatory-Drugs-and-bone-healing-in-animal-Models-Systematic-Review-and-Meta-Analysis.aspx.

Short-term perioperative parecoxib is not detrimental to shaft fracture healing in a rat model

Objectives

Experimental studies indicate that non-steroidal anti-inflammatory drugs (NSAIDs) may have negative effects on fracture healing. This study aimed to assess the effect of immediate and delayed short-term administration of clinically relevant parecoxib doses and timing on fracture healing using an established animal fracture model.

Methods

A standardized closed tibia shaft fracture was induced and stabilized by reamed intramedullary nailing in 66 Wistar rats. A ‘parecoxib immediate’ (Pi) group received parecoxib (3.2 mg/kg bodyweight twice per day) on days 0, 1, and 2. A ‘parecoxib delayed’ (Pd) group received the same dose of parecoxib on days 3, 4, and 5. A control group received saline only. Fracture healing was evaluated by biomechanical tests, histomorphometry, and dual-energy x-ray absorptiometry (DXA) at four weeks.

Results

For ultimate bending moment, the median ratio between fractured and non-fractured tibia was 0.61 (interquartile range (IQR) 0.45 to 0.82) in the Pi group, 0.44 (IQR 0.42 to 0.52) in the Pd group, and 0.50 (IQR 0.41 to 0.75) in the control group (n = 44; p = 0.068). There were no differences between the groups for stiffness, energy, deflection, callus diameter, DXA measurements (n = 64), histomorphometrically osteoid/bone ratio, or callus area (n = 20).

Conclusion

This study demonstrates no negative effect of immediate or delayed short-term administration of parecoxib on diaphyseal fracture healing in rats.

Cite this article: G. A. Hjorthaug, E. Søreide, L. Nordsletten, J. E. Madsen, F. P. Reinholt, S. Niratisairak, S. Dimmen. Short-term perioperative parecoxib is not detrimental to shaft fracture healing in a rat model. Bone Joint Res 2019;8:472–480. DOI: 10.1302/2046-3758.810.BJR-2018-0341.R1.

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.

The Effect of Non-Steroidal Anti-Inflammatory Drugs on Tendon-to-Bone Healing: A Systematic Review with Subgroup Meta-Analysis

BACKGROUND

There is some concern that non-steroidal anti-inflammatory drugs (NSAIDs) may impair the healing of certain musculoskeletal tissues. However, the effect of NSAIDs on the specialized fibrocartilaginous transition at the tendon-to-bone interface remains largely unknown. Thus, the purpose of the present study is to investigate the effect of NSAIDs on tendon-to-bone healing following acute injury or surgery.

METHODS

A systematic review was performed according to the 2009 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The PubMed (MEDLINE), Embase, Cumulative Index to Nursing and Allied Health (CINAHL), and SportDiscus databases were searched from the time of database inception to May 14, 2018 to identify all clinical and basic science studies investigating the effect of NSAIDs on tendon-to-bone healing. Methodological quality was assessed using the Methodological Index for Non-Randomized Studies (MINORS) and SYstematic Review Center for Laboratory animal Research (SYRCLE) risk of bias assessment tools for clinical and basic science studies, respectively. A qualitative synthesis of the literature was performed with a subgroup meta-analysis of homogeneous basic science studies.

RESULTS

A total of 13 studies, including three clinical and 10 basic science studies, were included. The overall methodological quality of the included clinical studies was poor, while assessment of the basic science studies revealed consistent areas at high or unclear risk of bias. Of the included clinical studies, a single study reported a higher rate of rotator cuff repair failure with selective (COX-2) NSAID use compared with non-selective NSAID use, while no clinical failures were noted with NSAID use following distal biceps tendon repair. Basic science studies had heterogeneous outcome reporting. A subgroup analysis of homogeneous animal studies revealed no significant effect of all NSAIDs (Standard Mean Difference [SMD] -1.05, 95% Confidence Interval [CI] -2.39-0.30, p=0.13) or non-selective NSAIDs on load to failure (SMD -0.62, 95% CI -1.26-0.02, p=0.06).

CONCLUSIONS

The current literature does not provide sufficient evidence for or against the use of NSAIDs following acute injury or surgical repair of the tendon-bone interface.Level of Evidence: IV.

Multimodal Analgesia in Foot and Ankle Surgery

Progress in surgical acute pain management has allowed most foot and ankle surgery to be performed in ambulatory outpatient surgical centers. Multimodal analgesia focuses on improving postoperative pain by combining pharmacologic and other modalities, addressing multiple pain mechanisms and receptor pathways while reducing adverse effects through lower doses of oral medications. Local anesthesia techniques provide excellent pain relief with few adverse events. Multimodal analgesia in foot and ankle surgery provides superior pain relief, and reduced opioid dependence and opioid-related side effects, improving patient satisfaction, safety, and timely return to function.

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.

Nonsteroidal Anti-inflammatory Drug Use in Horses

Nonsteroidal anti-inflammatory drugs (NSAIDs) are effective anti-inflammatory and analgesic agents and are arguably the most commonly used class of drugs in equine medicine. This article provides a brief review of the mechanism of action, therapeutic uses, pharmacokinetics, and adverse effects associated with their use in horses. The use of COX-2 selective NSAIDs in veterinary medicine has increased over the past several years and special emphasis is given to the use of these drugs in horses. A brief discussion of the use of NSAIDs in performance horses is also included.

Low Intensity Ultrasound for Promoting Soft Tissue Healing: A Systematic Review of the Literature and Medical Technology

Therapeutic ultrasound has been studied and used for the past seven decades to treat musculoskeletal injuries. Recently, a significant body of animal and human research has focused on the biomechanical effects of daily-applied, low intensity therapeutic ultrasound (LITUS) on soft tissue recovery. We performed a systematic review of the last two decades of LITUS literature to examine the effects on tendon, skeletal muscle, ligament, and tendon-bone junction injuries. LITUS facilitated tendon healing, with increased tensile strength and improved collagen alignment. For skeletal muscle and ligament injuries, LITUS increased cell proliferation during myoregeneration and improved tissue biomechanics (ultimate load, stiffness, energy absorption). LITUS aided tendon-bone junction healing through improved tissue function. Scientific evidence supports the use of LITUS to treat soft tissue injuries, and improve outcomes for musculoskeletal injuries and post-operative recovery. Lastly, we discuss the use of LITUS devices facilitating daily applied therapy in the home setting.

Non-Steroid Anti-Inflammatory Drugs Are Better than Acetaminophen on Fever Control at Acute Stage of Fracture

In addition to adequate surgical fixation and an aggressive rehabilitation program, pain relief is one of the most critical factors in the acute stage of fracture treatment. The most common analgesics are nonsteroid anti-inflammatory drugs and Acetaminophen, both of which relieve pain and reduce body temperature. In clinical experiences, they exhibit effective pain control; however, their influence on body temperature remains controversial. This study is aimed at determining the effects of analgesics at the acute stage of traumatic fracture by performing a clinical retrospective study of patients with fractures and a fracture animal model. The retrospective study revealed that, in the acetaminophen group, the mean value of postmedication body temperature (BT) was significantly higher than that of the premedication BT. The change in BT was highly related with the medication rather than other risk factors. Forty eight 12-week-old male Wistar rats were divided into 6 groups: a control group, fracture group, fracture-Acetaminophen group, Acetaminophen group, fracture-Arcoxia group, and Arcoxia group. Fracture rats were prepared by breaking their unilateral tibia and fibula. Their inflammation conditions were evaluated by measuring their serum cytokine level and their physiological status was evaluated by estimating their central temperature, heart rate, and mean blood pressure. The hepatic adverse effects were assessed by measuring the serum levels of aspartate aminotransferase (sGOT) and alanine aminotransferase (sGPT). The central temperature in the fracture-Acetaminophen group exceeded that in the groups fed normal saline water or Arcoxia. Accumulated hepatic injury was presented as steadily ascending curves of sGOT and sGPT. Inflammation-related cytokine levels were not higher in the Acetaminophen fracture group and were significantly lower in the fracture-Arcoxia group. Fever appeared to be aggravated by acetaminophen and more related to the elevation of hepatic enzymes than to the change in the inflammation-related cytokines. We suggest that acetaminophen may aggravate fever at the acute stage of fracture. This response is highly related to the accumulated and exacerbated side effects of hepatitis that are caused by the medication and trauma.

Pharmacological effects of a C-phycocyanin-based multicomponent nutraceutical in an in-vitro canine chondrocyte model of osteoarthritis

Multicomponent nutraceuticals are becoming increasingly popular treatments or adjunctive therapies for osteoarthritis in veterinary medicine despite lack of evidence of efficacy for many products. The objective of this study was to evaluate the anti-inflammatory and antioxidant activities of a commercially available C-phycocyanin-based nutraceutical and select constituent ingredients in an in-vitro model of canine osteoarthritis. Normal canine articular chondrocytes were used in an in-vitro model of osteoarthritis. Inflammatory conditions were induced using interleukin-1β. The nutraceutical preparation as a whole, its individual constituents, as well as carprofen were evaluated at concentrations of 0 to 250 μg/mL for reduction of the following inflammatory mediators and indicators of catabolism of the extracellular matrix: prostaglandin E2 (PGE2), tumor necrosis factor-α (TFN-α), interleukin-6 (IL-6), metalloproteinase-3 (MMP-3), nitric oxide, and sulfated glycosaminoglycans (sGAGs). Validated, commercially available assay kits were used for quantitation of inflammatory mediators. The antioxidant capacities, as well as cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), and lipoxygenase (LOX) inhibitory activities of the whole nutraceutical preparation and select constituents, were also assessed using validated commercially available assay kits. The antioxidant capacity of the nutraceutical and constituents was concentration-dependent. The nutraceutical and constituents appear to display anti-inflammatory activity primarily through the inhibition of COX-2. The nutraceutical displayed similar strength to carprofen in reducing TNF-α, IL-6, MMP-3, nitric oxide, and sGAGs at select concentration ranges. The C-phycocyanin (CPC)-based nutraceutical and constituents may be able to mediate 3 primary pathogenic mechanisms of osteoarthritis: inflammation, chondral degeneration, and oxidative stress in vitro. The nutraceutical may be clinically useful in veterinary medicine and its efficacy should be further investigated in vivo.

Effects of Nonsteroidal Anti-inflammatory Drugs on Osseointegration: A Review

The purpose of this study was to review the effects of nonsteroidal anti-inflammatory drugs on osseointegration and determine whether they cause failures in dental implants and whether patients who use them chronically can receive dental implants safely. A bibliographic electronic search was performed using the Cochrane Library, PubMed, and Medline databases, selecting articles published between January 1982 and December 2012. The search included the following keywords, either alone or combined: “nonsteroidal anti-inflammatory drugs,” “dental implants,” “bone healing,” and “osteoprogenitor cells.” The inclusion criteria were the following: randomized, double-blind, placebo-controlled clinical studies, in vivo animal model studies of osseointegration, and in vitro studies of the effects of these agents on osteoprogenitor cells. The literature search revealed 360 references. A total of 31 articles met the inclusion criteria, including 2 clinical trials, 20 animal studies, and 9 osteoprogenitor cell studies. The clinical trials revealed that cyclooxygenase-1 (COX-1) inhibitors did not impair osseointegration. The animal studies showed that any drug that is capable of inhibiting COX-2 may impair the osseointegration process. The in vitro studies showed that COX-2 inhibitors are the most potent depressors of osseointegration at the cellular level. Caution must be taken when selecting COX-2 nonsteroidal anti-inflammatory drugs during the postoperative period.

Copaiba oil effect on experimental jaw defect in Wistar rats

PURPOSE

To evaluate the effects of copaiba oil on jaw defects repair in Wistar rats treated with bioglass or adipose tissue.

METHODS

A jaw defect was randomly created in forty-two rats and filled with bioglass or adipose tissue. The two groups (Gbio and Gcell) were subdivided in three subgroups with seven animals each according to gavage administration: control (distillated water), oil (copaiba oil) and melox (meloxicam). Euthanasia was performed after forty post-operative days. The bone formation was analyzed regarding the histological aspects.

RESULTS

The osteoclasts activity was observed only in four subgroups (p=0.78). Regarding the osteoblasts presence, it was very similar between the subgroups, the difference was due to Gcell-melox (p=0.009) that presented less osteoblastic activity. The inflammatory cells were more evident in Gcell-melox subgroup, however, there was no difference in comparison with the other subgroups (p=0.52). Bone formation was observed in all subgroups, just two animals showed no bone formation even after 40 days. More than 50% of bone matrix mineralization was observed in 56% (23 animals) of the analyzed areas. The bone matrix mineralization was not different between subgroups (p=0.60).

CONCLUSIONS

The subgroups that received copaiba oil showed bone repair, although not statistically significant in comparison to subgroups treated with meloxicam or controls. Copaiba oil administered by gavage had no effect on bone repair in this experimental model.

Perioperative alendronate, risedronate, calcitonin and indomethacin treatment alters femoral stem fixation and periprosthetic bone mineral density in ovariectomized rats

BACKGROUND

Many factors affect implant stability and periprosthetic bone mineral density (BMD) following total joint arthroplasty. We asked whether perioperative alendronate, risedronate, calcitonin and indomethacine administration altered (1) femoral stem shear strength and periprosthetic bone mineral density BMD in ovariectomized rats and (2) whether there were differences in the effect of these drugs.

METHODS

Thirty overiectomized rats were divided into five groups and implanted with intramedullary mini-cortical screws in the femur. Four groups were treated with alendronate, risedronate, salmon calcitonin and indomethacin for 4 weeks preoperatively and 8 weeks postoperatively.

RESULTS

Although alendronate and risedronate increased the periprosthetic BMD more than calcitonin, they did not alter implant fixation compared to calcitonin. Indomethacin significantly decreased the BMD around the stem and implant stability compared to all other groups.

CONCLUSIONS

This study showed that perioperative treatment with bisphosphonates and calcitonin improved the BMD around the stems and implant stability. Although bisphosphonates increased the BMD more than calcitonin, there was no difference in implant stability. Indomethacin markedly decreased the periprosthetic BMD and implant stability. The main clinical significance of our study was the finding about the need to strictly avoid long-term use of high-dose nonsteroidal antiinflammatory drugs for patients who have major joint arthritis and a previous history of arthroplasty.

Effect of indomethacin and lactoferrin on human tenocyte proliferation and collagen formation in vitro

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used in patients with injuries and inflammation of tendon and ligament, and as post-surgical analgesics. The aim of this study is to investigate the effect of indomethacin, a classic NSAID and its combinational effect with an anabolic agent of skeletal tissue, lactoferrin, on the proliferation and collagen formation of human tenocytes in vitro. A factorial experimental design was employed to study the dose-dependent effect of the combination of indomethacin and lactoferrin. The results showed that indomethacin at high concentration (100 μM) inhibited human tenocyte proliferation in culture medium with 1-10% fetal bovine serum (FBS) in vitro. Also, high dose of indomethacin inhibited the collagen formation of human tenocytes in 1% FBS culture medium. Lactoferrin at 50-100 μg/ml promoted human tenocyte survival in serum-free culture medium and enhanced proliferation and collagen synthesis of human tenocytes in 1% FBS culture medium. When 50-100 μg/ml lactoferrin was used in combination with 100-200 μM indomethacin, it partially rescued the inhibitory effects of indomethacin on human tenocyte proliferation, viability and collagen formation. To our knowledge, it is the first evidence that lactoferrin is anabolic to human tenocytes in vitro and reverses potential inhibitory effects of NSAIDs on human tenocytes.

Fracture healing via periosteal callus formation requires macrophages for both initiation and progression of early endochondral ossification

The distribution, phenotype, and requirement of macrophages for fracture-associated inflammation and/or early anabolic progression during endochondral callus formation were investigated. A murine femoral fracture model [internally fixed using a flexible plate (MouseFix)] was used to facilitate reproducible fracture reduction. IHC demonstrated that inflammatory macrophages (F4/80(+)Mac-2(+)) were localized with initiating chondrification centers and persisted within granulation tissue at the expanding soft callus front. They were also associated with key events during soft-to-hard callus transition. Resident macrophages (F4/80(+)Mac-2(neg)), including osteal macrophages, predominated in the maturing hard callus. Macrophage Fas-induced apoptosis transgenic mice were used to induce macrophage depletion in vivo in the femoral fracture model. Callus formation was completely abolished when macrophage depletion was initiated at the time of surgery and was significantly reduced when depletion was delayed to coincide with initiation of early anabolic phase. Treatment initiating 5 days after fracture with the pro-macrophage cytokine colony stimulating factor-1 significantly enhanced soft callus formation. The data support that inflammatory macrophages were required for initiation of fracture repair, whereas both inflammatory and resident macrophages promoted anabolic mechanisms during endochondral callus formation. Overall, macrophages make substantive and prolonged contributions to fracture healing and can be targeted as a therapeutic approach for enhancing repair mechanisms. Thus, macrophages represent a viable target for the development of pro-anabolic fracture treatments with a potentially broad therapeutic window.

Effect of indomethacin on surface treatment and intracanal dressing of replanted teeth in dogs

PURPOSE

This study evaluated the healing process of teeth replanted after root treatment and intracanal dressing with indomethacin alone or indomethacin with calcium hydroxide (Ca[OH]2).

MATERIALS AND METHODS

Through a case-control study, 24 teeth of 6 adult dogs were extracted, dried, and divided into 4 groups according to the root surface treatment protocols performed before replantation and the intracanal medication used after replantation. In group 1 (negative control), root surfaces were treated by immersion in a 0.9% saline solution and then replanted. In the other groups, the roots were immersed for 10 minutes in Ca(OH)2 (group 2), indomethacin (group 3), or a solution of indomethacin and Ca(OH)2 (group 4). After 2 weeks, group 1 teeth were subjected to single-visit root canal treatment and obturation with gutta-percha and sealer consisting of zinc oxide and eugenol. The teeth in the other groups were subjected to intracanal dressing with the same material used for immersion. After an additional period of 28 weeks, the animals were euthanized and the jaws containing the replanted teeth were processed for histologic analysis. Histometric values were statistically analyzed, with significance set at a P value less than or equal to .05.

RESULTS

Group 1 exhibited significantly more normal periodontium than group 4 (P = .02). Total resorption was greater in group 4 than in group 1 (P = .02). No statistically significant difference in the percentage of surface resorption or in total inactive resorption was observed between the groups.

CONCLUSIONS

The findings of this study suggest that intracanal dressing and topical root treatment with Ca(OH)2 with or without indomethacin is not recommended for teeth dried for 50 minutes, but the use of indomethacin alone as root surface treatment for delayed tooth replantation deserves further study using longer drying periods. In addition, the present results suggest that a single-visit root canal, performed up to 2 weeks after replantation, might be indicated for teeth dried for up to 50 minutes.

NSAIDs and fracture healing

PURPOSE OF REVIEW

Published data raise concerns about the use of nonselective NSAIDs and selective cyclo-oxygenase (COX)-2 inhibitors as anti-inflammatory or analgesic drugs in patients after a recent fracture or who are undergoing (uncemented) arthroplasty or osteotomy. However, clinical reports on the effect of COX-2 inhibition on fracture healing in humans have been variable and inconclusive. This review gives an overview of the published data and an advice when to avoid NSAIDs.

RECENT FINDINGS

Prostaglandins play an important role as mediators of inflammation and COX are required for their production. Inflammation is an essential step in the fracture healing process in which prostaglandin production by COX-2 is involved. Data from animal studies suggest that NSAIDs, which inhibit COX-2, can impair fracture healing due to the inhibition of the endochondral ossification pathway. Animal data suggest that the effects of COX-2 inhibitors are dependent on the timing, duration, and dose, and that these effects are reversible.

SUMMARY

These animal data, together with the view of limited scientifically robust clinical evidence in humans, indicate that physicians consider only short-term administration of COX-2 inhibitors or other drugs in the pain management of patients who are in the phase of fracture or other bone defect healing. COX-2-inhibitors should be considered a potential risk factor for fracture healing, and therefore to be avoided in patients at risk for delayed fracture healing.

Monitoring tissue inflammation and responses to drug treatments in early stages of mice bone fracture using 50 MHz ultrasound

Bone fracture induces moderate inflammatory responses that are regulated by cyclooxygenase-2 (COX-2) or 5-lipoxygenase (5-LO) for initiating tissue repair and bone formation. Only a handful of non-invasive techniques focus on monitoring acute inflammation of injured bone currently exists. In the current study, we monitored in vivo inflammation levels during the initial 2 weeks of the inflammatory stage after mouse bone fracture utilizing 50 MHz ultrasound. The acquired ultrasonic images were correlated well with histological examinations. After the bone fracture in the tibia, dynamic changes in the soft tissue at the medial-posterior compartment near the fracture site were monitored by ultrasound on the days of 0, 2, 4, 7, and 14. The corresponding echogenicity increased on the 2nd, 4th, and 7th day, and subsequently declined to basal levels after the 14th day. An increase of cell death was identified by the positive staining of deoxynucleotidyl transferase dUTP nick end-labeling (TUNEL) assay and was consistent with ultrasound measurements. The increases of both COX-2 and Leukotriene B4 receptor 1 (BLT1, 5-LO-relative receptor), which are regulators for tissue inflammation, in the immunohistochemistry staining revealed their involvement in bone fracture injury. Monitoring the inflammatory response to various non-steroidal anti-inflammatory drugs (NSAIDs) treatments was investigated by treating injured mice with a daily oral intake of aspirin (Asp), indomethacin (IND), and a selective COX-2 inhibitor (SC-236). The Asp treatment significantly reduced fracture-increased echogenicity (hyperechogenicity, p<0.05) in ultrasound images as well as inhibited cell death, and expression of COX-2 and BLT1. In contrast, treatment with IND or SC-236 did not reduce the hyperechogenicity, as confirmed by cell death (TUNEL) and expression levels of COX-2 or BLT1. Taken together, the current study reports the feasibility of a non-invasive ultrasound method capable of monitoring post-fracture tissue inflammation that positively correlates with histological findings. Results of this study also suggest that this approach may be further applied to elucidate the underlying mechanisms of inflammatory processes and to develop therapeutic strategies for facilitating fracture healing.

Ketorolac administration does not delay early fracture healing in a juvenile rat model: a pilot study

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) are effective at controlling pain in children, especially in the treatment of fractures. Adult animal and adult clinical studies demonstrate conflicting evidence for the inhibitory relationship between NSAIDs and fracture healing. Published pediatric orthopaedic clinical studies do not demonstrate an inhibitory effect of ketorolac on bone healing. Little is known about the effects of any NSAID on bone formation in juvenile animals. This study investigates the effects of the NSAID ketorolac on fracture healing in a juvenile rat model.

METHODS

Unilateral surgically induced and stabilized tibial shaft fractures were created in 45 juvenile (3 to 4 wk old) male Sprague-Dawley rats. Either ketorolac (5 mg/kg; n=24) or saline (0.9% normal saline; n=21) was then administered to the rats 6 d/wk by intraperitoneal injections. Animals were then randomly assigned into time groups and euthanized at 7 days (n=8 ketorolac, n=7 saline), 14 days (n=8 ketorolac, n=7 saline), or 21 days (n=8 ketorolac, n=7 saline) postfracture. Biomechanical analysis was performed using a custom-designed 4-point bending loading apparatus. Statistics for tibial stiffness and strength data were performed using software package Systat 11. Specimens were also evaluated histologically using hematoxylin and eosin staining.

RESULTS

Strength and stiffness of all fractured tibiae increased over time from day 7 to day 21 regardless of treatment type. No statistical difference was found between the fractured tibiae strength or stiffness in the ketorolac or control-treated specimens at the same time point. In addition, the quality of the fracture callus was similar in both groups at each of the time points.

CONCLUSIONS

In this study of a juvenile rat model with a stabilized tibia fracture, fracture callus strength, stiffness, and histologic characteristics were not affected by the administration of ketorolac during the first 21 days of fracture healing.

CLINICAL RELEVANCE

The absence of inhibitory effects of ketorolac on early juvenile rat fracture healing supports the clinical practice of utilizing NSAIDs for analgesia in children with long bone fractures.

The effect of nonsteroidal anti-inflammatory drugs on tissue healing

PURPOSE

Non-selective (NSAIDs) and selective (COX-2) nonsteroidal anti-inflammatory drugs are commonly used for their analgesic and anti-inflammatory effects. Their role after orthopaedic surgery has been infrequently described and remains controversial because of unclear effects on soft tissue and bone healing. This study critically reviews the available literature to describe the effects of NSAIDs and COX-2 inhibitors on soft tissue and bone healing.

METHODS

A Medline search was performed using NSAIDs or COX-2 inhibitors and tissue healing. The combined search yielded 637 articles. Following exclusion, 44 articles were deemed relevant with 9 articles on soft tissue healing and 35 articles on bone healing. The available evidence is based primarily on animal data (39 studies), with considerable variation in study methods.

RESULTS

In regard to soft tissue healing, there is insufficient evidence of a detrimental effect when using either NSAIDs or COX-2 inhibitors at standard doses for ≤2 weeks. For soft tissue to bone healing, a limited number of studies demonstrate impairment in healing. However, with respect to bone healing, indomethacin appears to have a clear detrimental effect, with less substantial evidence for other NSAIDs.

CONCLUSIONS

Short-term, low-dose use of NSAIDs and COX-2 inhibitors does not appear to have a detrimental effect following soft tissue injury, but is inhibitory in cases involving bony healing. However, additional well-controlled human studies are necessary to draw more definitive conclusions regarding their role. Clinically, the prudent use of anti-inflammatory medications following sports medicine injuries and surgeries appears to be a reasonable option in clinical practice unless bone healing is required.

LEVEL OF EVIDENCE

III.

Effects of a selective cyclooxygenase-2 inhibitor (celecoxib) on fracture healing in rats

BACKGROUND

Several studies suggested that celecoxib interferes with bone healing while others contradict these findings. This study was conducted to investigate the effects of celecoxib on bone healing in rats femur mold with a dose based on body surface area conversion.

MATERIALS AND METHODS

72 adult female Sprague Dawley rats were randomly divided into three groups after the internal fixation operation of nondisplaced transverse mid diaphyseal fractures of the right femurs. Each group was treated with 1% methylcellulose, celecoxib (21 mg/kg/d) for 1 week, or celecoxib (21 mg/kg/d) for 4 weeks after surgeries respectively. Bone healing scores and callus formation were evaluated by radiographs at 3, 4, 6 weeks after surgeries. Half of these rats were sacrificed for histological analysis at 4 weeks after surgery. The remaining fractured femurs were evaluated by biomechanical tests at 6 weeks after surgery.

RESULTS

The mean radiographic scores for fracture healing of both short and long term groups were lower than that of the control group and the differences among the three groups were statistically significant (P < 0.05) at 3, 4, 6 weeks after surgery. The mean bone trabecula density of both groups was smaller than that of the control group and the differences were also statistically significant (P < 0.05) at 4 week. The maximum load, total energy and stiffness in both the short term and long term groups were significantly decreased compared with those in the control group (P < 0.05) at 6 week.

CONCLUSION

Both short term and long term sustained use of celecoxib in rat models has significantly inhibitory effects on rat fracture healing.

Perioperative glucocorticosteroid treatment delays early healing of a mandible wound by inhibiting osteogenic differentiation

AIM

The purpose of this study is to investigate the effects of dexamethasone on repair of a critical size defect of the mandible in male Sprague-Dawley rats.

MATERIALS AND METHODS

Fifty rats were divided into 2 groups: saline control and dexamethasone-treated groups. A 1 mm × 3 mm full-thickness bone defect was created at the inferior border of the mandible. Saline or dexamethasone was administered once a day for 5 days after postoperative palinesthesia. On days 1, 3, 6, 10 and 17, after cessation of drug administration, 5 samples from each group were analysed. The bone defect healing process was examined and analysed by stereology, radiology, histology and histochemical staining for total collagen, tartrate-resistant acid phosphatase staining for osteoclasts and immunohistochemical staining for the COX-2, RUNX2 and osteocalcin antigens.

RESULTS

The dexamethasone-treated rats exhibited significantly lower radiopacity properties compared to the control rats. Histological staining revealed that the osteogenic differentiation and maturation of a callus in the defect region was significantly delayed from day 1 to day 10 in the dexamethasone group after cessation of drug administration compared to the control group. Consistent with the histological data, the level of total collagen protein was significantly lower in the dexamethasone group than in the control group. However, there was no significant difference between the 2 groups at day 17. Immunohistochemical analysis of COX-2, RUNX2 and osteocalcin expression showed that, at day 1, COX-2 and RUNX2 expression in the dexamethasone group was significantly lower than in the control group. There was no significant difference in osteocalcin expression between the two groups at each time point. There was no significant difference in the number of osteoclasts between the two groups.

CONCLUSION

In a model of bone healing of a mandible defect, dexamethasone-treated rats exhibited impaired osteogenic differentiation and maturation due to the inhibition of COX-2, osteogenic gene, RUNX2 and collagen protein expression, which resulted in delayed bone repair. Although perioperative short-term therapy did not exhibit long-term effects on wound healing of the maxillofacial bone, the application of glucocorticoids should be cautiously considered in the clinic.

Aryl hydrocarbon receptor-mediated impairment of chondrogenesis and fracture healing by cigarette smoke and benzo(a)pyrene

The clinical literature strongly suggests that bone healing in cigarette smokers is impaired. Since cigarette smoke (CS) contains numerous polycyclic aromatic hydrocarbons (PAHs), and since dioxins impair bone formation in vivo via the Aryl Hydrocarbon Receptor (AHR), we investigated the impact of PAH/AHR signaling on chondrogenesis and on healing in a mouse tibial fracture model. We established that CS activates AHR signaling in fractures by up-regulating the AHR target gene cytochrome p4501A1 (Cyp1A1). For in vitro studies, we employed the mouse limb bud micromass chondrogenesis model. After confirming that chondrocytes express AHR during differentiation, we treated cells with a prototypical PAH found in CS, benzo(a)pyrene (BaP), or cigarette smoke extract (CSE). Both BaP and CSE strongly inhibited chondrogenesis in mesenchymal cells generated from E11 limb buds, with BaP also accelerating chondrocyte hypertrophy in cultures generated from E12 limb buds. Detection of DNA adducts in the BaP-treated cultures suggests that the distinct phenotypic effects of BaP may be due to the formation of reactive metabolites. Blockade of AHR signaling with the AHR antagonist MNF reverses the effects of BaP, but not CSE, suggesting that CSE inhibition of chondrogenesis is AHR-independent. Correlating with these results, tibial fracture calluses from BaP-treated mice were smaller and contained less mineralized tissue than vehicle controls. Overall, BaP is identified as a potent inhibitor of chondrogenesis in vitro with correlated effects on fracture healing similar to those of CS itself, suggesting a basis for PAHs as key compounds in the influence of CS on fracture repair.

Effects of paracetamol, non-steroidal anti-inflammatory drugs, acetylsalicylic acid, and opioids on bone mineral density and risk of fracture: results of the Danish Osteoporosis Prevention Study (DOPS)

Pain medication has been associated with fractures. We found higher weight in paracetamol and non-steroidal anti-inflammatory drugs (NSAID) users and lower vitamin D levels in opioid and acetylsalicylic acid users. None of the pain medications influenced bone mineral density or loss. NSAID were associated with an increased fracture risk.

INTRODUCTION

To study the effects of use of paracetamol, non-steroidal anti-inflammatory drugs (NSAID), acetylsalicylic acid (ASA), and opioids on bone mineral density (BMD) and risk of fractures.

METHODS

Two-thousand sixteen perimenopausal women followed for 10 years as part of a partly randomised comprehensive cohort study on hormone therapy (HT). BMD was measured at baseline and after 10 years by DXA (Hologic).

RESULTS

Paracetamol users were heavier (70.4 ± 13.4 vs. 67.7 ± 11.9 kg, 2p < 0.01) than non-users. NSAID users were heavier (71.6 ± 15.6 vs. 67.8 ± 11.9 kg, 2p = 0.04) than non-users. ASA users had lower 25-hydroxy-vitamin D (25OHD) levels (21.9 ± 9.3 vs. 25.3 ± 12.4 ng/ml, 2p < 0.01) than non-users. Opioid users had lower 25OHD (21.4 ± 8.4 vs. 25.2 ± 12.3 ng/ml) and lower intake of vitamin D (2.2 ± 1.1 vs. 3.1 ± 3.0 μg/day, 2p < 0.01) than non-users. Despite these differences, no baseline differences were present in spine, hip, forearm or whole body BMD. Over 10 years, no differences were present in BMD alterations except a small trend towards a higher BMD gain in the spine in users of paracetamol, NSAID, ASA, and opioids compared to non-exposed. After adjustment, NSAID exposed sustained more fractures (HR = 1.44, 95% CI 1.07-1.93) than non-users. For users of paracetamol and opioids, a non-significant trend towards more fractures was present after adjustment. For ASA users, no excess risk of fractures was present.

CONCLUSION

Significant differences exist between subjects exposed to pain medications and non-users. Despite an absence of an effect over time on BMD, users of NSAID experienced more fractures than expected. The reasons for this have to be explored in further studies.

Acute postoperative pain management in the older patient

Acute pain management in the older adult is both challenging and rewarding. This review addresses the difficulty with assessment of pain in the older adult, variations in the pain experience of older adults, physiological differences between the young and old, changes in pharmacokinetics and pharmacodynamics with age, and useful pharmacological treatments for acute pain in older adults. It then presents a few representative cases of pain management in older adults. The goal of this review is to provide relevant information that can be used to manage acute postoperative pain in the older adult.

Small animal bone healing models: standards, tips, and pitfalls results of a consensus meeting

Small animal fracture models have gained increasing interest in fracture healing studies. To achieve standardized and defined study conditions, various variables must be carefully controlled when designing fracture healing experiments in mice or rats. The strain, age and sex of the animals may influence the process of fracture healing. Furthermore, the choice of the fracture fixation technique depends on the questions addressed, whereby intra- and extramedullary implants as well as open and closed surgical approaches may be considered. During the last few years, a variety of different, highly sophisticated implants for fracture fixation in small animals have been developed. Rigid fixation with locking plates or external fixators results in predominantly intramembranous healing in both mice and rats. Locking plates, external fixators, intramedullary screws, the locking nail and the pin-clip device allow different degrees of stability resulting in various amounts of endochondral and intramembranous healing. The use of common pins that do not provide rotational and axial stability during fracture stabilization should be discouraged in the future. Analyses should include at least biomechanical and histological evaluations, even if the focus of the study is directed towards the elucidation of molecular mechanisms of fracture healing using the largely available spectrum of antibodies and gene-targeted animals to study molecular mechanisms of fracture healing. This review discusses distinct requirements for the experimental setups as well as the advantages and pitfalls of the different fixation techniques in rats and mice.

Harnessing and modulating inflammation in strategies for bone regeneration

Inflammation is an immediate response that plays a critical role in healing after fracture or injury to bone. However, in certain clinical contexts, such as in inflammatory diseases or in response to the implantation of a biomedical device, the inflammatory response may become chronic and result in destructive catabolic effects on the bone tissue. Since our previous review 3 years ago, which identified inflammatory signals critical for bone regeneration and described the inhibitory effects of anti-inflammatory agents on bone healing, a multitude of studies have been published exploring various aspects of this emerging field. In this review, we distinguish between regenerative and damaging inflammatory processes in bone, update our discussion of the effects of anti-inflammatory agents on bone healing, summarize recent in vitro and in vivo studies demonstrating how inflammation can be modulated to stimulate bone regeneration, and identify key future directions in the field.

Anesthetic considerations in orthopedic patients with or without trauma

Anesthetic management of orthopedic patients could vary from normal routine management to more challenging critical management depending on the state in which the patient is presented. Multimodal pain management strategies incorporating opioids, which are the mainstay drugs for pain management, along with adjunctive drugs like local anesthetics (eg, lidocaine), dissociative anesthetics (eg, ketamine), and alpha-2 agonists (eg, dexmedetomidine), could improve overall patient comfort and help prevent establishment of chronic pain pathways. Also, use of local nerve blocks can prevent nociception right at the point of origin. Orthopedic patients with multiple organ traumas like head injuries, spinal injuries, pulmonary fat embolism, compartment syndrome, or thoracic injuries are high-risk patients in which any life-threatening organ pathology should be addressed before the patient is put under general anesthesia. Interactions of various drugs like antibiotics and neuromuscular blocking agents used in the perioperative period in orthopedic patients should warrant a careful consideration with respect to their interactions with each other and other anesthetic drugs used.

Effect of Non-Steroidal Anti-Inflammatory Drugs on Bone Healing

Nonspecific and COX-2 selective nonsteroidal anti-inflammatory drugs (NSAIDs) function by inhibiting the cyclooxygenase isoenzymes and effectively reduce pain and inflammation attributed to acute or chronic musculoskeletal pathologies. However, use of NSAIDs as an analgesic is thought to negatively contribute to bone healing. This review strived to provide a thorough unbiased analysis of the current research conducted on animals and humans regarding NSAIDs and their effect on bone healing. Specifically, this review discusses the role of animal models, dosing regiments, and outcome parameters when examining discrepancies about NSAIDS and their effects on bone regeneration. The role of COX-2 in bone regeneration needs to be better defined in order to further elucidate the impact of NSAIDs on bone healing.

Prophylactic use of NSAIDs by athletes: a risk/benefit assessment

Athletes often seek artificial means to gain advantage and prolong participation when competing. This often involves taking naturally occurring or chemically synthesized compounds. The World Anti-Doping Agency does not prohibit the use of nonsteroidal anti-inflammatory drugs (NSAIDs) because these agents are not performance enhancing, and their analgesic and anti-inflammatory effects are at best performance enabling. Consequently, athletes have relatively unrestricted access to NSAIDs, which are readily available as over-the-counter drugs. However, concern has been raised on athletes' prophylactic use of these agents. Data from many sporting fields have consistently demonstrated that many individuals self-administer NSAIDs prior to athletic participation to prevent pain and inflammation before it occurs. However, scientific evidence for this approach is currently lacking, and athletes should be aware of the potential risks in using NSAIDs as a prophylactic agent. These agents are not benign, and can produce significant side effects, including gastrointestinal and cardiovascular conditions, as well as musculoskeletal and renal side effects. The latter side effects appear paradoxical to the rationale for prophylactic use of NSAIDs. This article discusses current observations regarding athlete use of NSAIDs, and the possible benefits and potential risks of their use.