Drugs and fracture repair

Methods to accelerate fracture healing - a narrative review from a clinical perspective

Bone regeneration is a complex pathophysiological process determined by molecular, cellular, and biomechanical factors, including immune cells and growth factors. Fracture healing usually takes several weeks to months, during which patients are frequently immobilized and unable to work. As immobilization is associated with negative health and socioeconomic effects, it would be desirable if fracture healing could be accelerated and the healing time shortened. However, interventions for this purpose are not yet part of current clinical treatment guidelines, and there has never been a comprehensive review specifically on this topic. Therefore, this narrative review provides an overview of the available clinical evidence on methods that accelerate fracture healing, with a focus on clinical applicability in healthy patients without bone disease. The most promising methods identified are the application of axial micromovement, electromagnetic stimulation with electromagnetic fields and direct electric currents, as well as the administration of growth factors and parathyroid hormone. Some interventions have been shown to reduce the healing time by up to 20 to 30%, potentially equivalent to several weeks. As a combination of methods could decrease the healing time even further than one method alone, especially if their mechanisms of action differ, clinical studies in human patients are needed to assess the individual and combined effects on healing progress. Studies are also necessary to determine the ideal settings for the interventions, i.e., optimal frequencies, intensities, and exposure times throughout the separate healing phases. More clinical research is also desirable to create an evidence base for clinical guidelines. To make it easier to conduct these investigations, the development of new methods that allow better quantification of fracture-healing progress and speed in human patients is needed.

Post-Fracture Care Program: Pharmacological Treatment of Osteoporosis in Older Adults with Fragility Fractures

PURPOSE OF REVIEW

To present and discuss the recently published scientific evidence on the approach, mode of action, and timing of osteoporosis therapy initiation after fragility fractures.

RECENT FINDINGS

A comprehensive management approach is required to reduce mortality and morbidity associated with fragility fractures. This will help to reduce the risk of missing the diagnosis of osteoporosis as the underlying disorder while at the same time promoting the timely treatment of osteoporosis. The target is to minimize the incidence of post-traumatic disability and to reduce the imminent fracture risk. This article will present a Bone-Care algorithm for the diagnosis and management of fragility fractures in patients presenting for trauma surgery. This algorithm has been developed based on recently published national as well as international guidelines for implementation in standard clinical practice. International figures revealed that only a small proportion of those patients at high risk of sustaining a fragility fracture receive osteoporosis therapy. Based on the best currently available evidence, it is safe to start osteoporosis therapy in the acute post-fracture period (the optimal therapeutic window of romosozumab is the late endochondral phase/throughout bone remodeling). The right Bone-Care pathway ensures the delivery of a comprehensive management approach that meets the global call to action. All parameters including risk, benefit, compliance, and cost should be considered on an individual base for all kinds of therapy.

Fluoroscopic-guided procedures of the lower extremity

This article reviews the literature and the authors' experiences regarding the performance of lower extremity fluoroscopically guided procedures from the hip to the toes. An overview of injections and aspirations, their indications, risks, and complications are provided, focusing on anesthetics, corticosteroids, and contrast agents. A variety of approaches to each joint and the associated pearls and pitfalls of each approach will be discussed.

Erythromycin Restores Osteoblast Differentiation and Osteogenesis Suppressed by Porphyromonas gingivalis Lipopolysaccharide

The macrolide erythromycin (ERM) inhibits excessive neutrophil accumulation and bone resorption in inflammatory tissues. We previously reported that the expression of developmental endothelial locus-1 (DEL-1), an endogenous anti-inflammatory factor induced by ERM, is involved in ERM action. Furthermore, DEL-1 is involved in the induction of bone regeneration. Therefore, in this study, we investigated whether ERM exerts an osteoblastogenic effect by upregulating DEL-1 under inflammatory conditions. We performed in vitro cell-based mechanistic analyses and used a model of Porphyromonas gingivalis lipopolysaccharide (LPS)-induced periodontitis to evaluate how ERM restores osteoblast activity. In vitro, P. gingivalis LPS stimulation suppressed osteoblast differentiation and bone formation. However, ERM treatment combined with P. gingivalis LPS stimulation upregulated osteoblast differentiation-related factors and Del1, indicating that osteoblast differentiation was restored. Alveolar bone resorption and gene expression were evaluated in a periodontitis model, and the results confirmed that ERM treatment increased DEL-1 expression and suppressed bone loss by increasing the expression of osteoblast-associated factors. In conclusion, ERM restores bone metabolism homeostasis in inflammatory environments possibly via the induction of DEL-1.

Osteoimmunology: The effect of autoimmunity on fracture healing and skeletal analysis

Understanding factors that affect bone response to trauma is integral to forensic skeletal analysis. It is essential in forensic anthropology to identify if impaired fracture healing impacts assessment of post-traumatic time intervals and whether a correction factor is required. This paper presents a synthetic review of the intersection of the literature on the immune system, bone biology, and osteoimmunological research to present a novel model of interactions that may affect fracture healing under autoimmune conditions. Results suggest that autoimmunity likely impacts fracture healing, the pathogenesis however, is under researched, but likely multifactorial. With autoimmune diseases being relatively common, significant clinical history should be incorporated when assessing skeletal remains. Future research includes the true natural healing rate of bone; effect of autoimmunity on this rate; variation of healing with different autoimmune diseases; and if necessary, development of a correction factor on the natural healing rate to account for impairment in autoimmunity.

NSAID Use and Effects on Pediatric Bone Healing: A Review of Current Literature

This systematic review evaluates and synthesizes the available peer-reviewed evidence regarding the impact of non-steroidal anti-inflammatory drugs (NSAIDs) on fracture healing in skeletally immature patients. Evidence supports the use of NSAIDs in this patient population for adequate pain control without increasing the risk of nonunion, particularly in long bone fractures and pseudoarthrosis after spine fusion. However, further clinical studies are needed to fill remaining gaps in knowledge, specifically with respect to the spectrum of available NSAIDs, dosage, and duration of use, in order to make broad evidence-based recommendations regarding the optimal use of NSAIDs during bone healing in skeletally immature patients.

Comparative Proteomic and Metabolomic Analysis of Human Osteoblasts, Differentiated from Dental Pulp Stem Cells, Hinted Crucial Signaling Pathways Promoting Osteogenesis

Population aging has been a global trend for the last decades, which increases the pressure to develop new cell-based or drug-based therapies, including those that may cure bone diseases. To understand molecular processes that underlie bone development and turnover, we followed osteogenic differentiation of human dental pulp stem cells (DPSCs) using a specific induction medium. The differentiation process imitating in vivo osteogenesis is triggered by various signaling pathways and is associated with massive proteome and metabolome changes. Proteome was profiled by ultrahigh-performance liquid chromatography and comprehensively quantified by ion mobility-enhanced mass spectrometry. From 2667 reproducibly quantified and identified proteins, 432 were differentially abundant by strict statistic criteria. Metabolome profiling was carried out by nuclear magnetic resonance. From 27 detected metabolites, 8 were differentially accumulated. KEGG and MetaboAnalyst hinted metabolic pathways that may be involved in the osteogenic process. Enrichment analysis of differentially abundant proteins highlighted PPAR, FoxO, JAK-STAT, IL-17 signaling pathways, biosynthesis of thyroid hormones and steroids, mineral absorption, and fatty acid metabolism as processes with prominent impact on osteoinduction. In parallel, metabolomic data showed that aminoacyl-tRNA biosynthesis, as well as specific amino acids, likely promote osteodifferentiation. Targeted immunoassays validated and complemented omic results. Our data underlined the complexity of the osteogenic mechanism. Finally, we proposed promising targets for future validation in patient samples, a step toward the treatment of bone defects.

The Effect of Diclofenac Sodium-Loaded PLGA Rods on Bone Healing and Inflammation: A Histological and Histomorphometric Study in the Femur of Rats

Implants made of poly(lactide-co-glycolide) (PLGA) are biodegradable and frequently provoke foreign body reactions (FBR) in the host tissue. In order to modulate the inflammatory response of the host tissue, PLGA implants can be loaded with anti-inflammatory drugs. The aim of this study was to analyze the impact of PLGA 80/20 rods loaded with the diclofenac sodium (DS) on local tissue reactions in the femur of rats. Special emphasis was put on bone regeneration and the presence of multinucleated giant cells (MGCs) associated with FBR. PLGA 80/20 alone and PLGA 80/20 combined with DS was extruded into rods. PLGA rods loaded with DS (PLGA+DS) were implanted into the femora of 18 rats. Eighteen control rats received unloaded PLGA rods. The follow-up period was of 3, 6 and 12 weeks. Each group comprised of six rats. Peri-implant tissue reactions were histologically and histomorphometrically evaluated. The implantation of PLGA and PLGA+DS8 rods induced the formation of a layer of newly formed bone islands parallel to the contour of the implants. PLGA+DS rods tended to reduce the presence of multi-nucleated giant cells (MGCs) at the implant surface. Although it is known that the systemic administration of DS is associated with compromised bone healing, the local release of DS via PLGA rods did not have negative effects on bone regeneration in the femora of rats throughout 12 weeks.

Characteristics of complete tibial fractures in California racehorses

BACKGROUND

Tibial fractures cause ~3% of racehorse deaths. Pre-existing stress fractures have been associated with multiple racing and training fractures, but not complete tibial fractures.

OBJECTIVES

To describe racehorse tibial fractures and compare signalment and exercise histories of affected and control racehorses.

STUDY DESIGN

Retrospective analysis of necropsy reports.

METHODS

Racehorses that had a complete tibial fracture (1990-2018) were retrospectively reviewed. Signalment and exercise histories of affected horses were compared to 1) racehorses that died because of non-tibial musculoskeletal injuries or 2) non-musculoskeletal cause and 3) age, sex, event-matched control racehorses. Tibial fracture prevalence was described relative to California racehorses that had at least one official work or race. Age, sex and limb distributions were compared between affected and control horses (Chi-square, Fisher's Exact test). Exercise history data were reduced to counts and rates of official high speed works, races and layups (periods without an official high speed work or race >60 days). Variables were compared among groups using matched logistic regression (P ≤ .05).

RESULTS

Tibial fractures in 115 horses (97% unilateral; 50% left, 47% right) occurred most commonly during training (68%) and in 2- to 3-year-old horses (73%). Fractures were predominantly comminuted (93%), diaphyseal (44%) and oblique (40%). Of 61 cases examined for callus, 64% had periosteal callus associated with fracture, most commonly in proximal (65%) and distal diaphyseal (27%) locations. Of 28 racehorses with known exercise history, 57% never raced and 36% had a layup. Affected horses had fewer official-timed works and events (official high speed works and races), number of active days and accumulated less distance in events and works (P < .05) than control horses.

MAIN LIMITATIONS

Retrospective review of necropsy reports by multiple pathologists over 28 years.

CONCLUSIONS

Tibial fractures were associated with pre-existing stress fracture early in career. Most fractures were associated with proximolateral stress fractures.

Progress in Photobiomodulation for Bone Fractures: A Narrative Review

Objective: The aim of this article is to examine current concepts and the future direction of implementing photobiomodulation (PBM) for fracture treatment. Background data: The effectiveness of PBM for bone regeneration has been demonstrated throughout in vitro studies and animal models. Yet, insufficient clinical trials have been reported on treating fractures with PBM. Materials and methods: A narrative review was composed on the basis of a literary search. Inclusion criteria consisted of studies between 2000 and 2019 using animal or human fracture models. Exclusion criteria consisted of studies that did not pertain to complete fractures or used other forms of intervention. Results: Ten animal studies on rats and rabbits and four clinical trials were found on using PBM for complete fractures. Conclusions: Based on positive outcomes in animal trials, parameter optimization of PBM for human fractures still requires extensive research on factors such as dosage, wavelength, penetration depth, treatment frequency, and the use of pulsed waves.

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.

Optimal bone fracture repair requires 24R,25-dihydroxyvitamin D3 and its effector molecule FAM57B2

The biological activity of 24R,25-dihydroxyvitamin D3 [24R,25(OH)2D3] remains controversial, but it has been suggested that it contributes to fracture healing. Cyp24a1-/- mice, synthesizing no 24R,25(OH)2D3, show suboptimal endochondral ossification during fracture repair, with smaller callus and reduced stiffness. These defects were corrected by 24R,25(OH)2D3 treatment, but not by 1,25-dihydroxyvitamin D3. Microarrays with Cyp24a1-/- callus mRNA identified FAM57B2 as a mediator of the 24R,25(OH)2D3 effect. FAM57B2 produced lactosylceramide (LacCer) upon specific binding of 24R,25(OH)2D3. Fam57b inactivation in chondrocytes (Col2-Cre Fam57bfl/fl) phenocopied the callus formation defect of Cyp24a1-/- mice. LacCer or 24R,25(OH)2D3 injections restored callus volume, stiffness, and mineralized cartilage area in Cyp24a1-null mice, but only LacCer rescued Col2-Cre Fam57bfl/fl mice. Gene expression in callus tissue suggested that the 24R,25(OH)2D3/FAM57B2 cascade affects cartilage maturation. We describe a previously unrecognized pathway influencing endochondral ossification during bone repair through LacCer production upon binding of 24R,25(OH)2D3 to FAM57B2. Our results identify potential new approaches to ameliorate fracture healing.

[Pharmacological treatment of osteoarthritis-related pain]

Joint pain due to osteoarthritis (OA) is often severe and disabling and affects a large proportion of the aging population impairing daily living and quality of life. Numerous pharmacological treatment approaches are available. Including major OA guidelines this review presents the current evidence of pharmacological therapies in OA-related pain and covers topical, oral and intraarticular treatment approaches. In patients with mild OA topical nonsteroidal antiinflammatory drugs (NSAIDs) can be recommended. Topical capsaicin can be used when other treatments are ineffective or contraindicated. In patients with moderate to severe OA oral NSAIDs are suggested at the lowest effective dose for the shortest possible duration to control symptoms. Importantly, drug-related side effects and gastrointestinal, cardiovascular and renal comorbidities need to be taken into account. In patients with multiple-joint OA and high risk of NSAID-induced adverse events duloxetine can be considered. The evidence of metamizole, symptomatic slow-acting drugs in osteoarthritis and other nutritional supplements in the treatment of OA pain is uncertain and the use of opioids is not routinely recommended. In patients suffering from severe OA-related pain intraarticular injections with glucocorticoids can be suggested to achieve short-term pain relief. Evidence for interventional approaches using hyaluronic acid or platelet-rich plasma is uncertain. Yet, the efficacy of pharmacological therapies in OA-related pain is often inconsistent and severe adverse events might occur. Thus, critical use of the different treatment options considering patient-related comorbidities and nonpharmacological therapies is of major importance.

Integrative Approach to Facilitate Fracture Healing: Topical Chinese Herbal Paste with Oral Strontium Ranelate

Strontium ranelate (SrR) is one of the pharmaceutical agents reported to be effective on the promotion of fracture healing. This study aimed to evaluate the integrative effect of the oral SrR with a topical Chinese herbal paste, namely, CDR, on facilitation of bone healing. The in vivo efficacy was evaluated using rats with tibial fracture. They were treated with either CDR topically, or SrR orally, or their combined treatments. The in vivo results illustrated a significant additive effect of CDR on SrR in increasing the yield load of the fractured tibia. The in vitro results showed that neither SrR nor CDR exhibited a cytotoxic effect on UMR106 and bone-marrow stem cell (BMSC), but both of them increased the proliferation of BMSC at low concentrations. The combination of CDR at 200 μg/mL with SrR at 200 or 400 μg/ml also showed an additive effect on increasing the ALP activity of BMSC. Both SrR and CDR alone reduced osteoclast formation, and the effective concentration of SrR to inhibit osteoclastogenesis was reduced in the presence of CDR. This integrative approach by combining oral SrR and topical CDR is effective in promoting fracture healing properly due to their additive effects on proosteogenic and antiosteoclastogenic properties.

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.

Strontium ranelate stimulates trabecular bone formation in a rat tibial bone defect healing process

Strontium ranelate treatment is known to prevent fractures. Here, we showed that strontium ranelate treatment enhances bone healing and affects bone cellular activities differently in intact and healing bone compartments: Bone formation was increased only in healing compartment, while resorption was reduced in healing and normal bone compartments.

INTRODUCTION

Systemic administration of strontium ranelate (SrRan) accelerates the healing of bone defects; however, controversy about its action on bone formation remains. We hypothesize that SrRan could affect bone formation differently in normal mature bone or in the bone healing process.

METHODS

Proximal tibia bone defects were created in 6-month-old female rats, which orally received SrRan (625 mg/kg/day, 5/7 days) or vehicle (control groups) for 4, 8, or 12 weeks. Bone samples were analyzed by micro-computed tomography and histomorphometry in various regions, i.e., metaphyseal 2nd spongiosa, a region close to the defect, within the healing defect and in cortical defect bridging region. Additionally, we evaluated the quality of the new bone formed by quantitative backscattered electron imaging and by red picosirius histology.

RESULTS

Healing of the bone defect was characterized by a rapid onset of bone formation without cartilage formation. Cortical defect bridging was detected earlier compared with healing of trabecular defect. In the healing zone, SrRan stimulated bone formation early and laterly decreased bone resorption improving the healing of the cortical and trabecular compartment without deleterious effects on bone quality. By contrast, in the metaphyseal compartment, SrRan only decreased bone resorption from week 8 without any change in bone formation, leading to little progressive increase of the metaphyseal trabecular bone volume.

CONCLUSIONS

SrRan affects bone formation differently in normal mature bone or in the bone healing process. Despite this selective action, this led to similar increased bone volume in both compartments without deleterious effects on the newly bone-formed quality.

Local infiltration analgesia: a 2-year follow-up of patients undergoing total hip arthroplasty

Purpose

Local infiltration analgesia (LIA) is commonly used for postoperative pain management following total hip arthroplasty (THA). However, the long-term effects of the component drugs are unclear. The aim of our study was to investigate functional outcome, quality of life, chronic post-surgical pain, and adverse events in patients within 2 years of undergoing THA.

Methods

The study was a secondary analysis of data from a previous larger study. Eighty patients were randomized to receive either intrathecal morphine (Group ITM) or local infiltration analgesia (Group LIA) for pain management in a double-blind study. The parameters measured were patient-assessed functional outcome [using the Hip dysfunction and Osteo-arthritis Outcome Score (HOOS) questionnaire], health-related quality of life [using the European Quality of Life–5 dimensions (EQ-5D) questionnaire and the 36-Item Short Form Health Survey (SF-36) score], and pain using the numeric rating score (NRS), with persistent post-surgical pain having a NRS of > 3 or a HOOS pain sub-score of > 30. All complications and adverse events were investigated during the first 2 years after primary surgery.

Results

Pain intensity and rescue analgesic consumption were similar between the groups after hospital discharge. No differences were found in HOOS or SF-36 score between the groups up to 6 months after surgery. A significant group × time interaction was seen in the EQ 5D form in favor of the LIA group. No between-group difference in persistent post-surgical pain was found at 3 or 6 months, or in adverse events up to 2 years after surgery.

Conclusion

Analysis of functional outcome, quality of life, and post-discharge surgical pain did not reveal significant differences between patients receiving LIA and those receiving ITM. LIA was found to be a safe technique for THA during the long-term follow-up. However, it should be noted that these conclusions are based on a limited number of patients.

Mechanisms of bone response to injury

Bone, despite its relatively inert appearance, is a tissue that is capable of adapting to its environment. Wolff’s law, first described in the 19th century, describes the ability of bone to change structure depending on the mechanical forces applied to it. The mechanostat model extended this principle and suggested that the amount of strain a bone detects depends on bone strength and the amount of muscle force applied to the bone. Experimental studies have found that low-magnitude, high-frequency mechanical loading is considered to be the most effective at increasing bone formation. The osteocyte is considered to be the master regulator of the bone response to mechanical loading. Deformation of bone matrix by mechanical loading is thought to result in interstitial fluid flow within the lacunar–canalicular system, which may activate osteocyte mechanosensors, leading to changes in osteocyte gene expression and ultimately increased bone formation and decreased bone resorption. However, repetitive strain applied to bone can result in microcracks, which may propagate and coalesce, and if not repaired predispose to catastrophic fracture. Osteocytes are a key component in this process, whereby apoptotic osteocytes in an area of microdamage promote targeted remodeling of the damaged bone. If fractures do occur, fracture repair can be divided into 2 types: primary and secondary healing. Secondary fracture repair is the most common and is a multistage process consisting of hematoma formation and acute inflammation, callus formation, and finally remodeling, whereby bone may return to its original form.

Effects of Teriparatide Compared with Risedronate on Recovery After Pertrochanteric Hip Fracture: Results of a Randomized, Active-Controlled, Double-Blind Clinical Trial at 26 Weeks

BACKGROUND

Osteoporosis drugs might affect fracture-healing. We therefore studied the effects of teriparatide in comparison with risedronate on recovery after pertrochanteric hip fractures.

METHODS

The study was a randomized, multicenter, active-controlled, 78-week trial comparing teriparatide (20 μg/day) with risedronate (35 mg/week) initiated within 2 weeks after fixation of a low-trauma pertrochanteric hip fracture (AO/OTA 31-A1 or 31-A2). The main inclusion criteria were a bone mineral density T-score of ≤-2.0 and 25-OH-vitamin D of ≥9.2 ng/mL. During the first 26 weeks, patients received study medication with oral or injectable placebo plus calcium and vitamin D in a double-blinded fashion. Secondary (Timed Up-and-Go [TUG] test, hip pain, Short Form [SF]-36 health status, and safety) and exploratory (radiographic outcomes and ability to walk) 26-week end points are reported.

RESULTS

Of the 224 patients who were randomized, 171 (86 teriparatide, 85 risedronate) were included in the analysis. The mean age was 77 ± 8 years, 77% were female, and 26% had a prior history of low-trauma fracture. The teriparatide group completed the TUG test in a shorter time at 6, 12, 18, and 26 weeks (differences of -5.7, -4.4, -3.1, and -3.1 seconds, respectively; p = 0.021 for the overall difference). They also reported less pain on a visual analog scale immediately after the TUG test at 12 and 18 weeks (adjusted absolute differences of 10.6 and 11.9 mm, respectively; p < 0.05). There were no significant between-group differences in the SF-36 score, Charnley hip pain score, ability to walk, or use of walking aids during follow-up. Radiographic healing at 6, 12, and 26 weeks, mechanical failure of the implant (teriparatide, 7; risedronate, 8), loss of reduction (teriparatide, 2; risedronate, 4), and nonunion (0 cases) were not significantly different. Mild hypercalcemia and hyperuricemia were more frequent with teriparatide.

CONCLUSIONS

Teriparatide was associated with less pain and a shorter time to complete the TUG test between 6 and 26 weeks compared with risedronate. Other fracture-recovery outcomes were similar. The results should be interpreted with caution as these were secondary end points.

LEVEL OF EVIDENCE

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Serum of patients with active rheumatoid arthritis inhibits differentiation of osteochondrogenic precursor cells

Delayed fracture healing is frequently experienced in patients with systemic inflammation such as during rheumatoid arthritis (RA). The reasons for this are diverse, but could also be caused by inflammatory cytokines and/or growth factors in serum from patients with active disease. We hypothesized that serum from patients with active RA contains circulating inflammatory factors that inhibit differentiation of osteochondrogenic precursors. Serum was obtained from 15 patients with active RA (active RA-sera) and from the same patients in clinical remission 1 year later (remission RA-sera; controls). The effect of active RA-sera on osteochondrogenic differentiation of chondrogenic ATDC5 cells and primary human periosteum-derived progenitor cells (HPDC) was determined in micromass culture. In ATDC5 cells, active RA-sera reduced Ki67 transcription levels by 40% and cartilage matrix accumulation by 14% at day 14, and Alp transcription levels by 16%, and matrix mineralization by 17% at day 21 compared with remission RA-sera. In HPDCs, active RA-sera inhibited metabolic activity by 8%, SOX9 transcription levels by 14%, and cartilage matrix accumulation by 7% at day 7 compared with remission RA-sera. In conclusion, sera from patients with active RA negatively affect differentiation of osteochondrogenic precursors, and as a consequence may contribute to delayed fracture healing in these patients.

Trends of non-union and prescriptions for non-steroidal anti-inflammatory drugs in the United States, 1993-2012

BACKGROUND AND PURPOSE

Surgical care and pain management for patients with fractures have evolved over the years. We wanted to ascertain if there were any changes in the incidence of non-unions and, if so, whether the use of non-steroidal anti-inflammatory drugs (NSAIDs), including COX-2 selective inhibitors, might have an effect.

PATIENTS AND METHODS

We used the National Inpatient Sample (NIS) to estimate the annual number of patients hospitalized for surgical treatment of a non-union between 1993 and 2012, and calculated age-adjusted rates of non-union. We estimated the prevalence of prescriptions for NSAIDs from 1996 through 2012 using the Medical Expenditure Panel Survey (MEPS). The interrupted time-series analysis was used to relate quarterly rates of non-union to changes in prescriptions for NSAIDs between 1996 and 2009.

RESULTS

The annual estimate of non-unions in the USA declined 30% from 25,634 in 1993 to 17,815 in 2012 (p < 0.001). Specifically, the age-adjusted rate of non-unions decreased by 44% from 8.6 per 10(5) persons in 1996 to 4.8 per 10(5) persons in 2012 (p < 0.001). However, there was an 8% increase in the incidence rate of non-unions (p = 0.003) between 2000 and 2004, when certain COX-2 selective inhibitors were on the market and their prescriptions were prevalent at around 6% among those with fractures. A drop in non-union estimates from 22,321 in 2010 to 18,789 in 2011 (p = 0.04) also coincided with a marked decrease in prescriptions for NSAIDs in patients with fractures, from 22% to 14% (p = 0.02).

INTERPRETATION

Non-unions in the USA declined substantially between 1993 and 2012, but this was interrupted by changes in prescriptions for NSAIDs, with sustained increases between 2000 and 2004 followed by transient decreases in 2005 and 2011.

Intrabody application of eptotermin alpha enhances bone formation in osteoporotic fractures of the lumbar spine; however, fails to increase biomechanical stability - results of an experimental sheep model

This study analyses the effect of eptotermin α application into fractured vertebrae. It is hypothesized that eptotermin α is capable to enhance bony healing of the osteoporotic spine. In 10 Merino sheep osteoporosis induction was performed by ovariectomy, corticosteroid therapy and calcium/phosphorus/vitamin D-deficient diet; followed by standardized creation of lumbar vertebral compression fractures (VCFs) type A3.1 and consecutive fracture reduction/fixation using expandable mesh cages. Randomly, intravertebral eptotermin α (G1) or no augmentation was added (G2). Macroscopic, micro-CT, and biomechanical evaluation assessed bony consolidation two months postoperatively: Micro-CT data revealed bony consolidation for all cases with significant increased callus development for G2 (60%) and BV/TV (bone volume/total volume 73.45%, osteoporotic vertebrae 35.76%). Neither group showed improved biomechanical stability. Eptotermin α enhanced mineralisation in VCFs in an experimental setup with use of cementless augmentation via an expandable cage. However, higher bone mineral density did not lead to superior biomechanical properties.

The effects of dabigatran etexilate on fracture healing in rats: An experimental study

BACKGROUND

Deep vein thrombosis leading to pulmonary embolism is one of the major complication after fracture. After a fracture occurs, the coagulation cascade activates thrombin, a protease that finally generates clotting. Dabigatran etexilate reduce clot formation by inhibiting thrombin. Dabigatran etexilate is a widely used drug for thromboprophylaxis. There is no study of the effects of dabigatran etexilate on fracture healing in the literature, so we aimed to evaluate the effects of dabigatran etexilate on fracture healing.

MATERIALS AND METHODS

Thirty-six female Sprague Dawley rats were divided into 6 groups, each consisting of 6 rats. In all rats, right tibias were used for the fracture model. An oral regimen of dabigatran etexilate suspension in 0.5% hydroxyethylcellulose was administered to the rats. Although the first and second groups received 10 mg/kg daily doses, the third and fourth groups received 50 mg/kg daily doses. The fifth and sixth groups were assigned as sham groups and only hydroxyethylcellulose solution was administered. The first, third and fifth groups were sacrificed on 14(th) days; whereas the second, fourth and sixth groups were sacrificed on 28(th) days. Results were evaluated radiologically and histologically.

RESULTS

Radiologically and histologically no statistically significant differences were observed on the 14(th) day between the first, third and fifth groups; and on the 28(th) days between the second, fourth and sixth groups.

CONCLUSION

Radiological and histological evaluations revealed that fracture healing was not affected by dabigatran etexilate. We think that dabigatran etexilate can be used for the prophylaxis of thromboembolism in patients with fractures, but further clinical studies are mandatory.

The effect of parathyroid hormone and teriparatide on fracture healing

INTRODUCTION

Daily subcutaneous injections of parathyroid hormone (PTH), and its synthetic peptide fragment, teriparatide (PTH 1-34, TPTD), have a net anabolic effect on bone and prevent osteoporotic fractures. TPTD is currently approved for this indication worldwide. Because of the anabolic effect, there is an interest in a role for TPTD (and, where available, human PTH 1-84) in improving bone healing after a fracture. PTH has been studied in animal fracture healing models and in a limited number of human trials. We have reviewed current literature regarding possible mechanisms and efficacy for PTH and TPTD to improve the healing process in the setting of various types of fractures.

AREAS COVERED

Our review focuses first on the role of PTH in normal bone. We then discuss mechanisms of normal bone healing as well as delayed and impaired fracture healing. We summarize pertinent animal data and then review human studies utilizing PTH or TPTD for fracture healing. In particular, we examine unique situations including osteoporotic fractures, diabetes, stress fractures, delayed or poor healing and combination with bisphosphonate therapy.

EXPERT OPINION

Available data indicate there is likely an important role for TPTD and PTH in promoting fracture healing in selected patients, but more clinical trial data are needed.

Low dose of propranolol does not affect rat osteotomy healing and callus strength

Experimental studies suggest that the β-blocker propranolol stimulates bone formation but little work has investigated its effect on fracture healing. In this study, we examined if a low dose of propranolol, previously shown to be preventive against bone loss in rats, improves bone repair. Female Wistar rats were injected with saline or propranolol (0.1 mg/kg/day) (n = 20/group), 5 days a week for 8 weeks. Three weeks after the beginning of treatment, all rats underwent a mid-diaphyseal transverse osteotomy in the left femur. Radiographic analysis of ostetomy healing was performed 2 and 5 weeks after osteotomy. Rats were sacrificed at 5 weeks and femora collected for measurements of fracture strength by torsional testing, callus volume, and mineral content by micro-CT analysis and histology of fracture callus. Eighty nine percent of osteotomies achieved apparent radiological union by 5 weeks in both groups. Propranolol treatment did not significantly alter the torsional strength of the fractured femur compared with controls. The volume and mineralization of fracture callus at 5 weeks were not significantly different in both groups. Histology showed that endochondral ossification was not affected by propranolol. Altogether, our results demonstrate that propranolol using the regimen described does not significantly improve or inhibit rat osteotomy healing and mechanical strength.

Incidence and predictors of morphometric vertebral fractures in patients with ankylosing spondylitis

Introduction

Ankylosing spondylitis (AS) is associated with an increased incidence of vertebral fractures (VFs); however the actual incidence and predictors of morphometric VFs are unknown. The present study examined the incidence and predictors of new VFs in a large AS cohort.

Methods

In total, 298 AS patients who fulfilled the modified New York criteria were enrolled and spinal radiographs were evaluated biennially. Clinical and laboratory data and radiographic progression were assessed according to the Bath AS Disease Activity Index, erythrocyte sedimentation rate, C-reactive protein (CRP), and the Stoke AS spine score (SASSS). VF was defined according to the Genant criteria. The incidence of VFs at 2 and 4 years was evaluated using the Kaplan-Meier method. The age-specific standardized prevalence ratio (SPR) for AS patients in comparison with the general population was calculated.

Results

Of 298 patients, 31 (10.8%) had previous VFs at baseline. A total of 30 new VFs occurred in 26 patients over 4 years. The incidence of morphometric VFs was 4.7% at 2 years and 13.6% at 4 years. Multivariate logistic regression analysis showed that previous VFs at baseline and increased CRP levels at 2 years were predictors of new VFs (odds ratio (OR) =12.8, 95% confidence interval (CI) = 3.6-45.3 and OR = 5.4, 95% CI = 1.4–15.9). The age-specific specific standardized prevalence ratio of morphometric VFs in AS was 3.3 (95% CI 2.1–4.5).

Conclusions

The incidence of morphometric VFs increased in AS. Previous VFs and increased CRP levels predicted future VFs. Further studies are needed to identify the effects of treatment interventions on the prevention of new VFs.

Patient-important outcome for the assessment of fracture repair

Current evidence indicates that fracture healing assessment is limited to the use of one or two domains (such as pain, range of motion or mobility) in any single study. Functional outcome measures, which include physician-rated or observer-based impairment ratings and patient self-reported or observer-based activity limitation measures, better position the effectiveness of a given intervention towards patient-important outcomes. Health status measures, for example, cover a wide-range of physical, emotional, and social health dimensions. In this paper, we will examine the utility of metrics to assess fracture healing that are important to both the patient and provider, with selected examples from the recent literature. We recommend outcome measures with established and verified reliability and validity. Policy-makers and other stakeholders need to have an accurate assessment of treatment outcome that includes changes in function over time-adequate measures, should be re-applied at periodic intervals.

Healing of the bone with anti-fracture drugs

INTRODUCTION

Fracture healing is a complex process that leads to the restoration of tissue integrity through bone repair and represents a unique physiological characteristic of bone. Developing a better understanding of a fracture is essential to plan best noninvasive treatment for the patient. In osteoporosis, the patient who suffers of a fragility fracture is recommended to initiate a treatment with compounds active in preventing other low-energy skeletal trauma. Pharmaceutical industries are developing controlled clinical trials aiming to evaluate the capability of osteoporosis drugs to accelerate fracture healing.

AREAS COVERED

In preparing this review, a search was made with key words encompassing 'osteoporosis anti-fracture drugs and bone repair/healing', 'antiresorptives and bone repair/healing', 'bone-forming agents and bone repair/healing', and 'osteoporosis/anti-fracture drugs in fractures'. The results published in the area of the use of registered anti-fracture drugs to improve fracture repair and the efforts made to recommend measures for clinical outcomes in fracture healing acceleration are described in this report.

EXPERT OPINION

At present, the use of systemic pharmacological agents active to improve fracture healing by the clinicians is controversial and clinicians and scientists must do a better job in determining the methods of assessment for fracture healing.

Immune and inflammatory pathways are involved in inherent bone marrow ossification

BACKGROUND

Bone marrow plays a key role in bone formation and healing. Although a subset of marrow explants ossifies in vitro without excipient osteoinductive factors, some explants do not undergo ossification. The disparity of outcome suggests a significant heterogeneity in marrow tissue in terms of its capacity to undergo osteogenesis.

QUESTIONS/PURPOSES

We sought to identify: (1) proteins and signaling pathways associated with osteogenesis by contrasting the proteomes of ossified and poorly ossified marrow explants; and (2) temporal changes in proteome and signaling pathways of marrow ossification in the early and late phases of bone formation.

METHODS

Explants of marrow were cultured. Media conditioned by ossified (n = 4) and poorly ossified (n = 4) subsets were collected and proteins unique to each group were identified by proteomic analysis. Proteomic data were processed to assess proteins specific to the early phase (Days 1-14) and late phase (Days 15-28) of the culture period. Pathways involved in bone marrow ossification were identified through bioinformatics.

RESULTS

Twenty-eight proteins were unique to ossified samples and eight were unique to poorly ossified ones. Twelve proteins were expressed during the early phase and 15 proteins were specific to the late phase. Several identified pathways corroborated those reported for bone formation in the literature. Immune and inflammatory pathways were specific to ossified samples.

CONCLUSIONS

The marrow explant model indicates the inflammatory and immune pathways to be an integral part of the osteogenesis process.

Drugs for bone healing

INTRODUCTION

The biological process of fracture healing is complex with influences that are both patient-dependent and related to the trauma experienced and stability of the fracture. Fracture healing complications negatively affect the patient's quality of life, even more when fractures occur in the elderly osteoporotic patients.

AREAS COVERED

In the polytherapy for bone regeneration, a high success rate was obtained with the use of growth factors, osteogenic cells, and osteoconductive factors. There have been high expectations that treatment with drugs active on bone remodeling would be efficient for acceleration of fracture healing. A literature search was undertaken using wording like "drug or pharmacology of fracture healing." This report will review the systemic pharmacological agents for which clinical trials documenting their efficacy on bone healing have been carried out or are underway.

EXPERT OPINION

At present the use of systemic pharmacological agents to enhance fracture healing in the clinical setting is still controversial. However, future clinical trials will offer the possibility to obtain data that will make possible the registration of a drug as a "healer."

Implications for fracture healing of current and new osteoporosis treatments: an ESCEO consensus paper

Osteoporotic fracture healing is critical to clinical outcome in terms of functional recovery, morbidity, and quality of life. Osteoporosis treatments may affect bone repair, so insights into their impact on fracture healing are important. We reviewed the current evidence for an impact of osteoporosis treatments on bone repair. Treatment with bisphosphonate in experimental models is associated with increased callus size and mineralization, reduced callus remodeling, and improved mechanical strength. Local and systemic bisphosphonate treatment may improve implant fixation. No negative impact on fracture healing has been observed, even after major surgery or when administered immediately after fracture. Experimental data for denosumab and raloxifene suggest no negative implications for bone repair. The extensive experimental results for teriparatide indicate increased callus formation, improved biomechanical strength, and greater external callus volume and total bone mineral content and density. Case reports and a randomized trial have produced mixed results but are consistent with a positive impact of teriparatide on clinical fracture healing. Studies with strontium ranelate in models of fracture healing indicate that it is associated with improved bone microstructure, callus volume, and biomechanical properties. Finally, there is experimental evidence for a beneficial effect of some of the agents currently being developed for osteoporosis, notably sclerostin antibody and DKK1 antibody. There is currently no evidence that osteoporosis treatments are detrimental for bone repair and some promising experimental evidence for positive effects on healing, notably for agents with a bone-forming mode of action, which may translate into therapeutic applications.

Differential gene expression analysis in fracture callus of patients with regular and failed bone healing

OBJECTIVE

Although several systemic and local factors are known to impair fracture healing, there is still no explanation, why some patients with sufficient fracture stability, showing none of the existing risk factors, still fail to heal normally. An investigation of local gene expression patterns in the fracture gap of patients with non-unions could decisively contribute to a better understanding of the pathophysiology of impaired fracture healing. For the first time, this study compares the expression of a large variety of osteogenic and chondrogenic genes in patients with regular and failed fracture healing.

METHODS

Between March 2006 and May 2007, a total of 130 patients who were surgically treated at the Berufsgenossenschaftliche Unfallklink Ludwigshafen were screened for the study. Tissue samples of patients with normal and failed fracture healing were collected intraoperatively. Patients were divided into groups depending on the fracture date, and only patients with fractures two to four weeks old and patients with non-unions more than 9 months old were included in the final analysis. For the gene expression analysis, a customised cDNA array - containing 226 genes involved in osteo- and chondrogenesis - was used.

RESULTS

In the cDNA array analysis, the expression of eight genes was significantly elevated two-fold or more in the group with failed fracture healing relative to the normal controls. Conversely, no genes were found to be expressed at a higher level in the control group. The identified genes are supposed to be involved in extracellular matrix assembly, cytoskeletal structure, and differentiative and proliferative processes.

CONCLUSIONS

The differences in gene expression pattern indicate a change in the composition and structure of the extracellular matrix, and a possible turn in the healing programme towards fibrous scar tissue formation, leading to non-union.

A single bisphosphonate infusion does not accelerate fracture healing in high tibial osteotomies

BACKGROUND

Bisphosphonates increase the callus size and strength in animal fracture studies. In a human non-randomized pilot study of high tibial osteotomies in knee osteoarthritis, using the hemicallotasis (HCO) technique, bisphosphonates shortened the healing time by 12 days. In the present randomized study, we wanted to determine whether a single infusion of zoledronic acid reduces the time to clinical osteotomy healing. Results from the same trial, showing improved pin fixation with zoledronate, have been published separately.

METHODS

46 consecutive patients (aged 35-65 years) were operated. At 4 weeks postoperatively, the patients were randomized to an intravenous infusion of either zoledronic acid or sodium chloride. Dual-energy X-ray absorptiometry (DEXA) was performed 10 weeks postoperatively. Radiographs were taken at 10 weeks and every second week until there was radiographic and clinical healing. Healing was evaluated blind, with extraction of the external fixator as the endpoint. At 1.5 years, an additional radiograph was taken and the hip-knee-ankle (HKA) angle measured to evaluate whether correction had been retained.

RESULTS

All osteotomies healed with no difference in healing time between the groups (77 (SD 7) days). Bone mineral density and bone mineral content, as assessed with DEXA, were similar between the groups. Radiographically, both groups had retained the acquired correction at the 1.5-year follow-up.

INTERPRETATION

In this randomized comparison, a single infusion of zoledronic acid increased the pin fixation of the external frame but did not shorten the healing time. In both groups, the external fixator was extracted almost 2 weeks earlier than in previous studies. The early extraction did not cause a loss of correction in either group.

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.

In vitro & in vivo assessment of a herbal formula used topically for bone fracture treatment

AIM OF THE STUDY

A novel topical paste used for fracture healing (FH), consisting of the extracts of six herbs, Radix Dipsaci, Ramulus Sambucus Williamsii, Rhizoma Notoginseng, Flos Carthami, Rhizoma Rhei and Fructus Gardeniae, was developed according to the classical theory of traditional Chinese medicine. This study aimed to determine the effectiveness of this formula, and some of its important chemical components in the promotion of fracture healing. The transdermal transport of FH was also examined.

MATERIALS AND METHODS

The osteogenic, angiogenic and nitric oxide suppressing effects of FH and its important chemical marker components were assessed by using osteoblastosacroma UMR-106 cells, human umbilical vein endothelial cells (HUVEC) and murine macrophage RAW264.7 cells, respectively. The bone healing effects of the FH paste and its transdermal absorption were determined using a rabbit fracture model. The callus sizes, bone specific alkaline phosphatase levels and biomechanical properties of the healed bone were assessed.

RESULTS

FH significantly increased the cell proliferation in UMR-106 and HUVEC cells and inhibited the nitric oxide production in murine macrophage in dose-dependent manner. Its important chemical components asperosaponin VI, ginsenoside Rg1 and emodin were shown to be acting positively in the respective in vitro studies. FH paste significantly improved the bone healing in the rabbit fracture model, as was indicated by the increases in callus size at weeks 2-5, and the elevations in bone specific alkaline phosphatase activities at weeks 5-6. The analysis using LC/MS/MS also showed the presence of important chemical marker components of the FH formula in the plasma after 8 weeks of topical treatment.

CONCLUSION

This study presents the first scientific evidence of the efficacy of a herbal paste in the promotion of fracture healing. There were evidences of transdermal transport of the chemical components, control the inflammation through nitric oxide inhibition, promotion of angiogenesis, and bone healing in the in vitro tests, as well as in the experimental animal.

[Drug-induced osteopathies. Drugs, pathogenesis, forms, diagnosis, prevention and therapy]

A number of drugs can have "side effects" on bone metabolism and formation, causing bone atrophy, impaired mineralisation, as well as osteonecrosis. In both clinical and general practitioner settings, these forms of bone damage have been hitherto considered as adverse drug side effects and have received insufficient attention; moreover, they have not been the subject of patient information. Preventive measures are not instigated prior to initiation of medication and even after onset of bone damage, therapeutic strategies are poorly implemented. Even fracture healing with its complex, staged course can be both positively and negatively influenced by a number of drugs and these effects require monitoring. Recommendations regarding practical screening and therapy of drug-induced osteopathies are presented.

Osteoblast-targeted disruption of glucocorticoid signalling does not delay intramembranous bone healing

OBJECTIVE

Glucocorticoids at pharmacological doses have been shown to interfere with fracture repair. The role of endogenous glucocorticoids in fracture healing is not well understood. We examined whether endogenous glucocorticoids affect bone healing in an in vivo model of cortical defect repair.

METHODS

Experiments were performed using a well characterised mouse model in which intracellular glucocorticoid signalling was disrupted in osteoblasts through transgenic overexpression of 11beta-hydroxysteroid-dehydrogenase type 2 (11beta-HSD2) under the control of a collagen type I promoter (Col2.3-11beta-HSD2). Unicortical bone defects (ø 0.8mm) were created in the tibiae of 7-week-old male transgenic mice and their wild-type littermates. Repair was assessed via histomorphometry, immunohistochemistry and microcomputed tomography (micro-CT) analysis at 1-3 weeks after defect creation.

RESULTS

At week 1, micro-CT images of the defect demonstrated formation of mineralized intramembranous bone which increased in volume and density by week 2. At week 3, healing of the defect was nearly complete in all animals. Analysis by histomorphometry and micro-CT revealed that repair of the bony defect was similar in Col2.3-11beta-HSD2 transgenic animals and their wild-type littermates at all time-points.

CONCLUSION

Disrupting endogenous glucocorticoid signalling in mature osteoblasts did not affect intramembranous fracture healing in a tibia defect repair model. It remains to be shown whether glucocorticoid signalling has a role in endochondral fracture healing.

Evidence for anti-osteoporosis therapy in acute fracture situations--recommendations of a multidisciplinary workshop of the International Society for Fracture Repair

The International Society for Fracture Repair convened a multidisciplinary workshop to assess the current evidence around the interaction between anti-osteoporosis drugs and the healing of incident fractures, with a view to making recommendations for clinical practice. The consensus was that there is no evidence-based reason to withhold anti-resorptive therapy while a fracture heals, whether or not the patient was taking such therapy when the fracture occurred. The workshop also considered existing models of service provision for secondary prevention and concluded that the essential ingredient for reliable delivery is the inclusion of a dedicated coordinator role. Several unresolved issues were defined as subjects for further research, including the question of whether continuous long-term administration of anti-resorptives may impair bone quality. The rapidly changing area requires re-assessment of drugs and their interaction with fracture healing in the near future.

Vascular endothelial growth factor: an essential component of angiogenesis and fracture healing

Fractures require adequate stability and blood supply to heal. The vascular supply to long bones is compromised in a fracture, and the ability to heal hinges on the ability of new blood vessels to proliferate from surrounding vessels in a process known as angiogenesis. This process is largely driven by the growth factor, vascular endothelial growth factor (VEGF), whose levels are increased locally and systemically during fracture healing. VEGF is involved in many steps throughout the fracture healing cascade, from initially being concentrated in fracture hematoma, to the promotion of bone turnover during the final remodeling phase. This article reviews the current literature surrounding the role of VEGF and other growth factors in reestablishing vascular supply to fractured bone, as well as medications and surgical techniques that may inhibit this process.

Cell-free and cell-based approaches for bone regeneration

The clinical augmentation of bone currently involves the use of autogenous or allogeneic bone grafts and synthetic materials, all of which are associated with limitations. Research on the safe enhancement of bone formation concerns the potential value of scaffolds, stem cells, gene therapy, and chemical and mechanical signals. Optimal scaffolds are engineered to provide mechanical stability while supporting osteogenesis, osteoconduction and/or osteoinduction. Scaffold materials include natural or synthetic polymers, ceramics, and composites. The resorption, mechanical strength and efficacy of these materials can be manipulated through structural and chemical design parameters. Cell-seeded scaffolds contain stem cells or progenitor cells, such as culture-expanded marrow stromal cells and multipotent skeletal progenitor cells sourced from other tissues. Despite extensive evidence from proof-of-principle studies, bone tissue engineering has not translated to clinical practice. Much of the research involves in vitro and animal models that do not replicate potential clinical applications. Problem areas include cell sources and numbers, over-reliance on existing scaffold materials, optimum delivery of factors, control of transgene expression, vascularization, integration with host bone, and the capacity to form bone and marrow structures in vivo. Current thinking re-emphasizes the potential of biomimetic materials to stimulate, enhance, or control bone's innate regenerative capacity at the implantation site.

Injectable corticosteroid and local anesthetic preparations: a review for radiologists

Corticosteroids and local anesthetics are some of the most commonly administered medications in radiology departments. These medications have marked variability in their formulations, which may increase their adverse event profile for specific procedures. In particular, certain corticosteroid preparations are associated with adverse central nervous system (CNS) sequelae. This is most likely due to distal embolization by particulate formulations. Nonparticulate steroid formulations are not associated with such events. Local anesthetics have severe CNS and cardiac adverse effects if injected intravascularly and have recently been associated with intraarticular chondrolysis if used in large doses. This review discusses these medications with particular emphasis on their established and postulated adverse effects. The administering radiologist should be aware of these potential effects and how best to reduce their occurrence.

Interference by adrenaline with chondrogenic differentiation through suppression of gene transactivation mediated by Sox9 family members

In contrast to osteoblasts, little attention has been paid to the functional expression of adrenergic signaling machineries in chondrocytes. Expression of mRNA was for the first time demonstrated for different adrenergic receptor (AdR) subtypes in chondrogenic ATDC5 cells and mouse metatarsals isolated before vascularization in culture, but not for other molecules related to adrenergic signaling. In neonatal mouse tibial sections, beta(2)AdR and alpha(2a)AdR mRNA expression was found in chondrocytes at different developmental stages by in situ hybridization. Exposure to adrenaline significantly suppressed expression of several maturation markers through the cAMP/protein kinase A pathway activated by beta(2)AdR without affecting cellular proliferation in both cultured ATDC5 cells and metatarsals. Adrenaline also significantly inhibited gene transactivation by sry-type HMG box 9 (Sox9) family members essential for chondrogenic differentiation in a manner prevented by the general betaAdR antagonist propranolol, with a concomitant significant decrease in the levels of Sox6 mRNA and corresponding protein, in ATDC5 cells and primary cultured mouse costal chondrocytes. Systemic administration of propranolol significantly promoted the increased expression of mRNA for collagen I and collagen X, but not for collagen II, in callus of fractured femur in mice. These results suggest that adrenaline may interfere with chondrogenic differentiation through downregulation of Sox6 expression for subsequent suppression of gene transactivation mediated by Sox9 family members after activation of beta(2)AdR expressed by chondrocytes.

Modulation of the inflammatory response for enhanced bone tissue regeneration

Proinflammatory cytokines are infamous for their catabolic effects on tissues and joints in both inflammatory diseases and following the implantation of biomedical devices. However, recent studies indicate that many of these same molecules are critical for triggering tissue regeneration following injury. This review will discuss the role of inflammatory signals in regulating bone regeneration and the impact of both immunomodulatory and antiinflammatory pharmacologic agents on fracture healing, to demonstrate the importance of incorporating rational control of inflammation into the design of tissue engineering strategies.

The influence of osteoporosis in femoral fracture healing time

AIM

In order to assess the effect of osteoporosis on healing time, the files of 165 patients with femoral shaft fractures that were treated in our institution with locked-reamed intramedullary nailing were retrospectively reviewed.

PATIENTS AND METHODS

Patients with open fractures, pathological fractures, revision surgery, severe brain injuries and prolonged ITU stay were excluded. In all patients the Singh-index score for osteoporosis and the canal bone ratio (CBR) were assigned. Sixty-six patients fulfilled the inclusion criteria. Patients were divided into two groups; group A (29 patients) consisted of patients over 65 years old with radiological evidence of osteoporosis and group B (37 patients) of patients between 18 and 40 years old with no signs of osteoporosis.

RESULTS

In all group A patients Singh score < or =4 and CBR>0.50 were assigned, suggesting the presence of osteoporosis, whereas all group B patients were assigned with Singh score > or =5 and CBR<0.48. Fractures of group A healed in 19.38+/-5.9 weeks (12-30) and in group B 16.19+/-5.07 weeks (10-28), P=0.02.

CONCLUSIONS

Fracture healing of nailed femoral diaphyseal fractures is significantly delayed in older osteoporotic patients. Further studies are required to clarify the exact impact of osteoporosis in the whole healing process.

Effects of gold coating on experimental implant fixation

Insertions of orthopedic implants are traumatic procedures that trigger an inflammatory response. Macrophages have been shown to liberate gold ions from metallic gold. Gold ions are known to act in an antiinflammatory manner by inhibiting cellular NF-kappaB-DNA binding and suppressing I-kappa B-kinase activation. The present study investigated whether gilding implant surfaces augmented early implant osseointegration and implant fixation by its modulatory effect on the local inflammatory response. Ion release was traced by autometallographic silver enhancement. Gold-coated cylindrical porous coated Ti6Al4V implants were inserted press-fit in the proximal part of tibiae in nine canines and control implants without gold inserted contralateral. Observation time was 4 weeks. Biomechanical push-out tests showed that implants with gold coating had approximately 50% decrease in mechanical strength and stiffness. Histomorphometrical analyses showed gold-coated implants had a decrease in overall total bone-to-implant contact of 35%. Autometallographic analysis revealed few cells loaded with gold close to the gilded implant surface. The findings demonstrate that gilding of implants negatively affects mechanical strength and osseointegration because of a significant effect of the released gold ions on the local inflammatory process around the implant. The possibility that a partial metallic gold coating could prolong the period of satisfactory mechanical strength, however, cannot be excluded.

Global burden of trauma: Need for effective fracture therapies

Orthopedic trauma care and fracture management have advanced significantly over the last 50 years. New developments in the biology and biomechanics of the musculoskeletal system, fixation devices, and soft tissue management have greatly influenced our ability to care for musculoskeletal injuries. Many therapies and treatment modalities have the potential to transform future orthopedic treatment by decreasing invasive procedures and providing shorter healing times. Promising results in experimental models have led to an increase in clinical application of these therapies in human subjects. However, for many modalities, precise clinical indications, timing, dosage, and mode of action still need to be clearly defined. In order to further develop fracture management strategies, predict outcomes and improve clinical application of newer technologies, further research studies are needed. Together with evolving new therapies, the strategies to improve fracture care should focus on cost effectiveness. This is a great opportunity for the global orthopedic community, in association with other stakeholders, to address the many barriers to the delivery of safe, timely, and effective care for patients with musculoskeletal injuries in developing countries.