Blood loss and transfusion risk in intramedullary nailing for subtrochanteric fractures

BACKGROUND

The incidence of hip fractures and subtrochanteric fractures in particular is increasing, along with the globally expanding aging population. Intramedullary nailing remains the 'gold standard' of their treatment. Blood loss can be a result of the original trauma, but also secondary to the subsequent surgical insult, especially during the reaming of the intramedullary canal.

OBJECTIVES

The aim of our study was to report on the blood loss and incidence of blood transfusion in patients presenting with a subtrochanteric fracture treated with intramedullary nailing. Most importantly, we aim to identify factors associated with the need for transfusion within the first 48 h post-operatively.

METHODS

Following institutional board approval, 431 consecutive patients (131 males; age: 79.03 years old, SD 13.68 years) presenting in a Level 1 Trauma Centre with a subtrochanteric fracture treated with an intramedullary nail were retrospectively identified, over an 8-year period. Exclusion criteria included patients with high energy injuries, pathological fractures, primary operations at other institutions and patients lost to follow-up. To identify risk factors leading to increased risk of transfusion, we first compared patients requiring intra-operative transfusion or transfusion during the first 48 h post-operatively against those who did not require transfusion. This was then followed by multivariate regression analysis adjusted for confounding factors to identify the most important risk factors associated with need for transfusion within the first 48 h post-operatively.

RESULTS

Incidence of blood transfusion was 6.0% pre-operatively, compared to 62.7% post-operatively. A total of 230 patients (52.3%) required either intra-operative transfusion or transfusion during the first 48 h following surgery. Patients having a transfusion within the first 48 h post-operatively had a higher incidence of escalation in their care (p = 0.050), LOS (p = 0.015), 30-day (p = 0.033) and one-year mortality (p = 0.004). Multivariate regression analysis adjusted for confounding factors identified that the most important association of a need for transfusion within the first 48 post-operative hours was a pre-operative Hb <100 g/L (OR 6.64); a nail/canal ratio <70% (OR 3.92), followed by need for open reduction (OR 2.66). Fracture involving the lesser trochanter was also implicated with an increased risk (OR 2.08). Additionally, pre-operative moderate/severe renal impairment (OR 4.56), as well as hypoalbuminaemia on admission (OR 2.10) were biochemical predictors of an increased risk of transfusion. Most importantly, the need for transfusion was associated with an increase in 30-day mortality (OR 12.07).

CONCLUSION

Several patient, fracture and surgery related factors are implicated with an increased risk for transfusion within the first 48-h post-operatively. Early identification, and where possible correction of these factors can potentially reduce blood loss and risk of transfusion, along with all the associated sequelae and mortality risk.

LEVEL OF EVIDENCE

III.

Subtrochanteric femoral fractures and intramedullary nailing complications: a comparison of two implants

INTRODUCTION

Intramedullary (IM) nails are considered the 'gold' standard treatment for subtrochanteric femoral fractures. The incidence and risk factors for re-operation in subtrochanteric fractures remain unclear. Furthermore, no studies have compared the outcomes of different nailing systems used to treat subtrochanteric fractures in the same study population.

AIMS/OBJECTIVES

Our study aimed to (i) investigate the cumulative incidence and factors associated with an increased risk of re-operation in subtrochanteric fractures treated with a long intramedullary (IM) nail, (ii) compare the outcomes of subtrochanteric fractures treated with long Affixus and Gamma nails, and (iii) establish whether the addition of a proximal anti-rotation screw in the Affixus nail confers any clinical benefit.

METHODS

A retrospective review of all adult patients admitted to a level 1 trauma centre with a subtrochanteric femur fracture treated with a long cephalomedullary IM nail over an 8-year period was conducted. Exclusion criteria were primary surgery performed at another institution, prophylactic nailing because of tumours, incomplete fractures, and patients who were lost to follow-up or died before fracture healing. Data variables were assessed for normality prior to determining the use of either parametric or non-parametric tests. Logistic regression analysis was performed to identify potential factors associated with re-operation. For the comparison between the two nail types, patients were matched into two groups of 119 each by age (10-year intervals), gender and mechanism of injury (low energy, high energy and pathological fractures). A p-value < 0.05 was considered significant. The Kaplan-Meier nail survival curve was used to demonstrate the survival of each nail. Data were analysed using the statistical package R (R version 3.6.0).

RESULTS

A total of 309 subtrochanteric fractures were treated with a distally locked long IM nail (re-operation rate: 22.33%) over an 8-year period. Logistic regression identified six factors associated with an increased risk of re-operation, including age < 75 years old, use of a long Gamma nail, pre-injury coxa-vara femoral neck shaft angles, an immediate post-operative reduction angle of > 10° varus, deep wound infection and non-union. Following matching, we compared the two long cephalomedullary nailing systems used (Gamma versus Affixus nail). The only differences identified from the unadjusted analysis were a higher overall incidence of nail failure in Gamma nails due to any cause, re-operation, and impingement of the nail tip distally against the anterior femoral cortex. When we corrected for covariates, no significant differences remained evident between the two nails. From the Kaplan-Meier nail survival curves, however, the Affixus nail demonstrated better survivorship up to 5 years post-implantation in terms of nail failure and re-operation for all causes. Finally, the addition of a proximal anti-rotation screw in the Affixus nail did not seem to confer any benefit.

CONCLUSION

We reported a 22.3% re-operation rate in our cohort of subtrochanteric fractures treated with a long IM nail. We have identified six risk factors associated with re-operation: age < 75 years old, pre-injury femoral neck shaft angle, choice of nail, varus reduction angle, fracture-related infection and non-union. The addition of a proximal anti-rotation screw in the Affixus nail did not confer any benefit.

Highlights on Advancing Frontiers in Tissue Engineering

The field of tissue engineering continues to advance, sometimes in exponential leaps forward, but also sometimes at a rate that does not fulfill the promise that the field imagined a few decades ago. This review is in part a catalog of success in an effort to inform the process of innovation. Tissue engineering has recruited new technologies and developed new methods for engineering tissue constructs that can be used to mitigate or model disease states for study. Key to this antecedent statement is that the scientific effort must be anchored in the needs of a disease state and be working toward a functional product in regenerative medicine. It is this focus on the wildly important ideas coupled with partnered research efforts within both academia and industry that have shown most translational potential. The field continues to thrive and among the most important recent developments are the use of three-dimensional bioprinting, organ-on-a-chip, and induced pluripotent stem cell technologies that warrant special attention. Developments in the aforementioned areas as well as future directions are highlighted in this article. Although several early efforts have not come to fruition, there are good examples of commercial profitability that merit continued investment in tissue engineering. Impact statement Tissue engineering led to the development of new methods for regenerative medicine and disease models. Among the most important recent developments in tissue engineering are the use of three-dimensional bioprinting, organ-on-a-chip, and induced pluripotent stem cell technologies. These technologies and an understanding of them will have impact on the success of tissue engineering and its translation to regenerative medicine. Continued investment in tissue engineering will yield products and therapeutics, with both commercial importance and simultaneous disease mitigation.

Biological and molecular profile of fracture non-union tissue: A systematic review and an update on current insights

Fracture non‐union represents a common complication, seen in 5%–10% of all acute fractures. Despite the enhancement in scientific understanding and treatment methods, rates of fracture non‐union remain largely unchanged over the years. This systematic review investigates the biological, molecular and genetic profiles of both (i) non‐union tissue and (ii) non–union‐related tissues, and the genetic predisposition to fracture non‐union. This is crucially important as it could facilitate earlier identification and targeted treatment of high‐risk patients, along with improving our understanding on pathophysiology of fracture non‐union. Since this is an update on our previous systematic review, we searched the literature indexed in PubMed Medline; Ovid Medline; Embase; Scopus; Google Scholar; and the Cochrane Library using Medical Subject Heading (MeSH) or Title/Abstract words (non‐union(s), non‐union(s), human, tissue, bone morphogenic protein(s) (BMPs) and MSCs) from August 2014 (date of our previous publication) to 2 October 2021 for non‐union tissue studies, whereas no date restrictions imposed on non–union‐related tissue studies. Inclusion criteria of this systematic review are human studies investigating the characteristics and properties of non‐union tissue and non–union‐related tissues, available in full‐text English language. Limitations of this systematic review are exclusion of animal studies, the heterogeneity in the definition of non‐union and timing of tissue harvest seen in the included studies, and the search term MSC which may result in the exclusion of studies using historical terms such as ‘osteoprogenitors’ and ‘skeletal stem cells’. A total of 24 studies (non‐union tissue: n = 10; non–union‐related tissues: n = 14) met the inclusion criteria. Soft tissue interposition, bony sclerosis of fracture ends and complete obliteration of medullary canal are commonest macroscopic appearances of non‐unions. Non‐union tissue colour and surrounding fluid are two important characteristics that could be used clinically to distinguish between septic and aseptic non‐unions. Atrophic non‐unions had a predominance of endochondral bone formation and lower cellular density, when compared against hypertrophic non‐unions. Vascular tissues were present in both atrophic and hypertrophic non‐unions, with no difference in vessel density between the two. Studies have found non‐union tissue to contain biologically active MSCs with potential for osteoblastic, chondrogenic and adipogenic differentiation. Proliferative capacity of non‐union tissue MSCs was comparable to that of bone marrow MSCs. Rates of cell senescence of non‐union tissue remain inconclusive and require further investigation. There was a lower BMP expression in non‐union site and absent in the extracellular matrix, with no difference observed between atrophic and hypertrophic non‐unions. The reduced BMP‐7 gene expression and elevated levels of its inhibitors (Chordin, Noggin and Gremlin) could potentially explain impaired bone healing observed in non‐union MSCs. Expression of Dkk‐1 in osteogenic medium was higher in non‐union MSCs. Numerous genetic polymorphisms associated with fracture non‐union have been identified, with some involving the BMP and MMP pathways. Further research is required on determining the sensitivity and specificity of molecular and genetic profiling of relevant tissues as a potential screening biomarker for fracture non‐unions.

Anatomical reconstruction of the anterior inferior tibiofibular ligament in elite athletes using InternalBrace suture tape

AIMS

The ideal management of acute syndesmotic injuries in elite athletes is controversial. Among several treatment methods used to stabilize the syndesmosis and facilitate healing of the ligaments, the use of suture tape (InternalBrace) has previously been described. The purpose of this study was to analyze the functional outcome, including American Orthopaedic Foot & Ankle Society (AOFAS) scores, knee-to-wall measurements, and the time to return to play in days, of unstable syndesmotic injuries treated with the use of the InternalBrace in elite athletes.

METHODS

Data on a consecutive group of elite athletes who underwent isolated reconstruction of the anterior inferior tibiofibular ligament using the InternalBrace were collected prospectively. Our patient group consisted of 19 elite male athletes with a mean age of 24.5 years (17 to 52). Isolated injuries were seen in 12 patients while associated injuries were found in seven patients (fibular fracture, medial malleolus fracture, anterior talofibular ligament rupture, and posterior malleolus fracture). All patients had a minimum follow-up period of 17 months (mean 27 months (17 to 35)).

RESULTS

All patients returned to their pre-injury level of sports activities. One patient developed a delayed union of the medial malleolus. The mean return to play was 62 days (49 to 84) for isolated injuries, while the patients with concomitant injuries returned to play in a mean of 104 days (56 to 196). The AOFAS score returned to 100 postoperatively in all patients. Knee-to-wall measurements were the same as the contralateral side in 18 patients, while one patient lacked 2 cm compared to the contralateral side.

CONCLUSION

This study suggests the use of the InternalBrace in the management of unstable syndesmotic injuries offers an alternative method of stabilization, with good short-term results, including early return to sports in elite athletes. Cite this article: Bone Joint J 2022;104-B(1):68-75.

Management of subtrochanteric femur fractures: is open reduction associated with poor outcomes?

Purpose

The aim of this study was to identify factors associated with the need for open reduction in subtrochanteric femoral fractures and investigate the effect of cerclage wiring compared to open reduction alone, on the development of complications, especially infection and non-union.

Methods

All consecutive patients with a fracture involving the subtrochanteric region were retrospectively identified, over an 8-year period. Data documented and analysed included patient demographics, fracture characteristics, patient comorbidities, time to fracture union and development of complications.

Results

A total of 512 patients met the inclusion criteria (523 fractures). Open reduction was performed in 48% (247) of the fractures. Following matching and regression analysis, we identified diaphyseal extension of the fracture to be associated with an open reduction (OR: 2.30; 95% CI 1.45–3.65; p < 0.001). Open reduction was also associated with an increased risk of superficial infection (OR: 7.88; 95% CI 1.63–38.16; p = 0.010), transfusion within 48 h following surgery (OR: 2.44; 95% CI 1.96–4.87; p < 0.001) and a prolonged surgical time (OR: 3.09; 95% CI 1.96–4.87; p < 0.001). The risk of non-union, deep infection and overall mortality was not increased with open reduction. The use of cerclage wires [50 out of 201 fractures (24.9%) treated with an open reduction] to achieve anatomical reduction as compared to open reduction alone significantly reduced the risk of non-union (OR: 0.20; 95% CI 0.06–0.74; p = 0.015).

Conclusion

Open reduction of subtrochanteric fractures is not associated with an increased risk of deep infection and non-union, even though it is associated with an increased risk of superficial infection, prolonged surgical time and transfusion. The use of cerclage wire is associated with reduced risk of non-union with little evidence of an increase in complications.

Level of evidence

III.

NSAIDs inhibit bone healing through the downregulation of TGF-β3 expression during endochondral ossification

INTRODUCTION & AIMS

Non Steroidal Anti-Inflammatory drugs (NSAIDs) are potent inhibitors of post-traumatic pain. Several studies have highlighted that NSAIDs could exert a negative effect on bone healing process possibly by down-regulating chondrogenesis and endochondral ossification. The aim of the study is to explore the potential mechanism though which NSAIDs can affect chondrogenesis. M&M: Trabecular bone from the fracture site was isolated from 10 patients suffering from long bone fractures. Mesenchymal Stem Cells (MSCs) were isolated following collagenase digestion and functional assays to assess the effect of diclofenac sodium on chondrogenesis were performed. Gene expression analysis of 84 key molecules was performed.

RESULTS

Diclofenac sodium inhibits chondrogenic differentiation and induces a strong inhibition of prostaglandin E-2 (PGE-2) production during chondrogenic differentiation. Replenishment of PGE-2 did not reverse this negative effect. Chondrogenic inhibition is similar in cells treated only for the first week of chondrogenic differentiation or continuously for 3 weeks. Gene analysis shows a strong downregulation of TGF-β3 and FGF-1 while TNF was upregulated.

CONCLUSION

NSAIDs seem to affect the transition phase of mesenchymal stem cells towards functional chondrocytes. This effect is unrelated to the endogenous production of PGE-2. The downregulation of the expression of key molecules like TGF-β3 seem to be the underlying mechanism.

Mortality and Medical Complications of Subtrochanteric Fracture Fixation

The aim of this study was to define the incidence and investigate the associations with mortality and medical complications, in patients presenting with subtrochanteric femoral fractures subsequently treated with an intramedullary nail, with a special reference to advancement of age. Materials and Methods: A retrospective review, covering an 8-year period, of all patients admitted to a Level 1 Trauma Centre with the diagnosis of subtrochanteric fractures was conducted. Normality was assessed for the data variables to determine the further use of parametric or non-parametric tests. Logistic regression analysis was then performed to identify the most important associations for each event. A p-value < 0.05 was considered significant. Results: A total of 519 patients were included in our study (age at time of injury: 73.26 ± 19.47 years; 318 female). The average length of hospital stay was 21.4 ± 19.45 days. Mortality was 5.4% and 17.3% for 30 days and one year, respectively. Risk factors for one-year mortality included: Low albumin on admission (Odds ratio (OR) 4.82; 95% Confidence interval (95%CI) 2.08-11.19), dementia (OR 3.99; 95%CI 2.27-7.01), presence of pneumonia during hospital stay (OR 3.18; 95%CI 1.76-5.77) and Charlson comorbidity score (CCS) > 6 (OR 2.94; 95%CI 1.62-5.35). Regarding the medical complications following the operative management of subtrochanteric fractures, the overall incidence of hospital acquired pneumonia (HAP) was 18.3%. Patients with increasing CCS (CCS 6-8: OR 1.69; 95%CI 1.00-2.84/CCS > 8: OR 2.02; 95%CI 1.03-3.95), presence of asthma/chronic obstructive pulmonary disease (COPD) (OR 2.29; 95%CI 1.37-3.82), intensive care unit (ICU)/high dependency unit (HDU) stay (OR 3.25; 95%CI 1.77-5.96) and a length of stay of more than 21 days (OR 8.82; 95%CI 1.18-65.80) were at increased risk of this outcome. The incidence of post-operative delirium was found to be 10.2%. This was associated with pre-existing dementia (OR 4.03; 95%CI 0.34-4.16), urinary tract infection (UTI) (OR 3.85; 95%CI 1.96-7.56), need for an increased level of care (OR 3.16; 95%CI 1.38-7.25), pneumonia (OR 2.29; 95%CI 1.14-4.62) and post-operative deterioration of renal function (OR 2.21; 95%CI 1.18-4.15). The incidence of venous thromboembolism (VTE) was 3.7% (pulmonary embolism (PE): 8 patients; deep venous thrombosis (DVT): 11 patients), whilst the incidence of myocardial infarction (MI)/cerebrovascular accidents (CVA) was 4.0%. No evidence of the so called "weekend effect" was identified on both morbidity and mortality. Regression analysis of these complications did not reveal any significant associations. Conclusions: Our study has opened the field for the investigation of medical complications within the subtrochanteric fracture population. Early identification of the associations of these complications could help prognostication for those who are at risk of a poor outcome. Furthermore, these could be potential "warning shots" for clinicians to act early to manage and in some cases prevent these devastating complications that could potentially lead to an increased risk of mortality.

Recent advances in 3D bioprinting of musculoskeletal tissues

The musculoskeletal system is essential for maintaining posture, protecting organs, facilitating locomotion, and regulating various cellular and metabolic functions. Injury to this system due to trauma or wear is common, and severe damage may require surgery to restore function and prevent further harm. Autografts are the current gold standard for the replacement of lost or damaged tissues. However, these grafts are constrained by limited supply and donor site morbidity. Allografts, xenografts, and alloplastic materials represent viable alternatives, but each of these methods also has its own problems and limitations. Technological advances in three-dimensional (3D) printing and its biomedical adaptation, 3D bioprinting, have the potential to provide viable, autologous tissue-like constructs that can be used to repair musculoskeletal defects. Though bioprinting is currently unable to develop mature, implantable tissues, it can pattern cells in 3D constructs with features facilitating maturation and vascularization. Further advances in the field may enable the manufacture of constructs that can mimic native tissues in complexity, spatial heterogeneity, and ultimately, clinical utility. This review studies the use of 3D bioprinting for engineering bone, cartilage, muscle, tendon, ligament, and their interface tissues. Additionally, the current limitations and challenges in the field are discussed and the prospects for future progress are highlighted.

Safety Considerations in 3D Bioprinting Using Mesenchymal Stromal Cells

Three-dimensional (3D) bioprinting has demonstrated great potential for the fabrication of biomimetic human tissues and complex graft materials. This technology utilizes bioinks composed of cellular elements placed within a biomaterial. Mesenchymal stromal cells (MSCs) are an attractive option for cell selection in 3D bioprinting. MSCs can be isolated from a variety of tissues, can pose vast proliferative capacity and can differentiate to multiple committed cell types. Despite their promising properties, the use of MSCs has been associated with several drawbacks. These concerns are related to the ex vivo manipulation throughout the process of 3D bioprinting. The herein manuscript aims to present the current evidence surrounding these events and propose ways to minimize the risks to the patients following widespread expansion of 3D bioprinting in the medical field.

Inflammatory Profile and Osteogenic Potential of Fracture Haematoma in Humans

Fracture haematoma forms immediately after fracture and is considered essential for the bone healing process. Its molecular composition has been briefly investigated with our current understanding being based on animal studies. This study aims to analyse the inflammatory cytokine content of fracture haematoma in humans and determine its effect on osteoprogenitor cells. Twenty-three patients were recruited following informed consent. Peripheral blood, fracture haematoma and bone were collected. A Luminex assay on the levels of 34 cytokines was performed and autologous peripheral blood samples served as control. Mesenchymal Stem Cells (MSCs) were isolated following collagenase digestion and functional assays were performed. Gene expression analysis of 84 key osteogenic molecules was performed. Thirty-three inflammatory cytokines were found to be significantly raised in fracture haematoma when compared to peripheral serum (p < 0.05). Amongst the most raised molecules were IL-8, IL-11 and MMP1, -2 and -3. Fracture haematoma did not significantly affect MSC proliferation, but ALP activity and calcium deposition were significantly increased in the MSCs undergoing osteogenic differentiation. Medium supplementations with fracture haematoma resulted in a statistically significant upregulation of osteogenic genes including the EGF, FGF2 and VEGFA. This seems to be the pathway involved in the osteogenic effect of fracture haematoma on bone cells. In conclusion, fracture haematoma is found to be a medium rich in inflammatory and immunomodulatory mediators. At the same time, it contains high levels of anti-inflammatory molecules, regulates osteoclastogenesis, induces angiogenesis and the production of the extracellular matrix. It appears that fracture haematoma does not affect osteoprogenitor cells proliferation as previously thought, but induces an osteogenic phenotype.

In situ three-dimensional printing for reparative and regenerative therapy

Three-dimensional (3D) bioprinting is an emerging biofabrication technology, driving many innovations and opening new avenues in regenerative therapeutics. The aim of 3D bioprinting is to fabricate grafts in vitro, which can then be implanted in vivo. However, the tissue culture ex vivo carries safety risks and thereby complicated manufacturing equipment and practice are required for tissues to be implanted in the humans. The implantation of printed tissues also adds complexities due to the difficulty in maintaining the structural integrity of fabricated constructs. To tackle this challenge, the concept of in situ 3D bioprinting has been suggested in which tissues are directly printed at the site of injury or defect. Such approach could be combined with cells freshly isolated from patients to produce custom-made grafts that resemble target tissue and fit precisely to target defects. Moreover, the natural cellular microenvironment in the body can be harnessed for tissue maturation resulting in the tissue regeneration and repair. Here, we discuss literature reports on in situ 3D printing and we describe future directions and challenges for in situ 3D bioprinting. We expect that this novel technology would find great attention in different biomedical fields in near future.

Reliability of the classification of proximal femur fractures: Does clinical experience matter?

BACKGROUND

Radiographic fracture classification helps with research on prognosis and treatment. AO/OTA classification into fracture type has shown to be reliable, but further classification of fractures into subgroups reduces the interobserver agreement and takes a considerable amount of practice and experience in order to master.

QUESTIONS/PURPOSES

We assessed: (1) differences between more and less experienced trauma surgeons based on hip fractures treated per year, years of experience, and the percentage of their time dedicated to trauma, (2) differences in the interobserver agreement between classification into fracture type, group, and subgroup, and (3) differences in the interobserver agreement when assessing fracture stability compared to classifying fractures into type, group and subgroup.

METHODS

This study used the Science of Variation Group to measure factors associated with variation in interobserver agreement on classification of proximal femur fractures according to the AO/OTA classification on radiographs. We selected 30 anteroposterior radiographs from 1061 patients aged 55 years or older with an isolated fracture of the proximal femur, with a spectrum of fracture types proportional to the full database. To measure the interobserver agreement the Fleiss' kappa was determined and bootstrapping (resamples = 1000) was used to calculate the standard error, z statistic, and 95% confidence intervals. We compared the Kappa values of surgeons with more experience to less experienced surgeons.

RESULTS

There were no statistically significant differences in the Kappa values on each classification level (type, group, subgroup) between more and less experienced surgeons. When all surgeons were combined into one group, the interobserver reliability was the greatest for classifying the fractures into type (kappa, 0.90; 95% CI, 0.83 to 0.97; p < 0.001), reflecting almost perfect agreement. When comparing the kappa values between classes (type, group, subgroup), we found statistically significant differences between each class. Substantial agreement was found in the clinically relevant groups stable/unstable trochanteric, displaced/non-displaced femoral neck, and femoral head fractures (kappa, 0.60; 95% CI, 0.53 to 0.67, p < 0.001).

CONCLUSIONS

This study adds to a growing body of evidence that relatively simple distinctions are more reliable and that this is independent of surgeon experience.

Drug-eluting implants for the suppression of metastatic bone disease: current insights

INTRODUCTION

The fixation of impending or pathologic fractures is challenging and their successful management can have a favourable impact on the quality of life of the patient. The progression of the metastatic bone disease can cause significant pain and disability but also could result in the loosening and subsequent failure of the implants. To prevent the additional local growth, postoperative radiotherapy is often recommended, and many patients receive endocrine or chemotherapy.

AREAS COVERED

Several reports support the antineoplastic drugs to bone cement as an adjuvant to improve implant stability as well as to prevent local cancer progression and failure of reconstructive devices used to treat patients with pathologic fractures. The aim of the present review is to present our current understanding on the effect of local delivery of antineoplastic drugs at the bone site.

EXPERT COMMENTARY

Encouraging evidence support the application of bone cement loaded with antineoplastic drugs to fill defects and strengthen the fixation of orthopaedic implants. This is an inexpensive and safe method that can improve implant stability, prevent local cancer progression and failure of reconstructive devices. To fully evaluate its clinical effectiveness randomized clinical studies are needed.

Intravascular Papillary Endothelial Hyperplasia (Masson's Tumor) Involving the Knee Synovium

INTRODUCTION

Intravascular papillary endothelial hyperplasia or Masson's tumor is a rare benign lesion of vascular origin characterized by abnormal proliferation of endothelial cells.

CASE REPORT

We present a case of this lesion involving the knee joint of a Caucasian woman who was referred to our institution for the evaluation of recurrent right knee pain. Her symptoms have started insidiously 5 years earlier following minor trauma. Recurrent symptomatic knee effusion was the cardinal symptom. Following the surgical excision of the lesion, recurrence occurred 2 years later. The tumor was successfully treated with embolization of its vascular supply.

CONCLUSION

Masson's tumor involving the synovium is an uncommon condition. The intermittent symptomatology and normal appearance of biopsies taken arthroscopically during asymptomatic periods can make the diagnosis challenging. Although resection is proposed to prevent recurrence, embolization of the vascular supply of the tumor can be a viable alternative.

The role of Iloprost on bone edema and osteonecrosis: Safety and clinical results

INTRODUCTION

Iloprost is a commercially available prostaglandin I₂ (PGI₂) analogue that is shown to have antithrombotic, vasodilatative and antiproliferative effects. A number of clinical studies have shown that Iloprost can be effective in the management of bone marrow oedema and the treatment of avascular necrosis. The aim of this manuscript is to present our current understanding on the effect of Iloprost on the treatment of these conditions.

AREAS COVERED

The authors offer a comprehensive review of the existing literature on the experimental and clinical studies analysing the effect of Iloprost on bone, bone marrow oedema and avascular necrosis.

EXPERT OPINION

The available data from the clinical studies suggest that Iloprost has limited effect in advanced stages of avascular necrosis. However, literature suggests that Iloprost administration can be a viable option in the management of bone marrow oedema and early stages of osteonecrosis. Despite these promising results its effect on bone homeostasis needs further elucidation. Moreover, further data on its safety, dosage and efficiency through randomized multicenter studies are desirable in order to reach final conclusions.

Cuboid Injuries

Cuboid fractures are rare injuries. A number of different treatment methods have been proposed including plaster immobilization, open reduction, and internal fixation or external fixation. Bone grafting is commonly used to restore bony length. The majority of the current literature suggests that the loss of length of the lateral column and articular congruency are the two criteria opting for the surgical management of these fractures. Nevertheless, the exact indications and ideal management of these fractures are not established mainly due to the rarity of these injuries and the paucity of literature.

Modulation of cartilage's response to injury: Can chondrocyte apoptosis be reversed?

Osteoarthritis is characterized by a chronic, progressive and irreversible degradation of the articular cartilage associated with joint inflammation and a reparative bone response. More than 100 million people are affected by this condition worldwide with significant health and welfare costs. Our available treatment options in osteoarthritis are extremely limited. Chondral or osteochondral grafts have shown some promising results but joint replacement surgery is by far the most common therapeutic approach. The difficulty lies on the limited regeneration capacity of the articular cartilage, poor blood supply and the paucity of resident progenitor stem cells. In addition, our poor understanding of the molecular signalling pathways involved in the senescence and apoptosis of chondrocytes is a major factor restricting further progress in the area. This review focuses on molecules and approaches that can be implemented to delay or even rescue chondrocyte apoptosis. Ways of modulating the physiologic response to trauma preventing chondrocyte death are proposed. The use of several cytokines, growth factors and advances made in altering several of the degenerative genetic pathways involved in chondrocyte apoptosis and degradation are also presented. The suggested approaches can help clinicians to improve cartilage tissue regeneration.

Dementia and fragility fractures: Issues and solutions

Dementia and fragility fractures are two conditions that pose significant morbidity and mortality to the elderly population. The occurrence of the 'gerontic' boom as a result of improved healthcare meant a continued increase in the prevalence of fragility fractures and dementia. This represents a major public health problem with significant socioeconomic repercussions. It is therefore important for healthcare professionals to gain a better understanding on the relationship between these two commonly co-existing conditions. In this review, we present the available literature surrounding the relationship between fragility fractures and dementia, and the common challenges faced in the management of these two conditions. Combining evidence from the literature along with our current clinical practice, we propose a management pathway aimed at early diagnosis, prevention and management of these two often co-existing conditions. This alongside with a multidisciplinary approach will not only translate to improved patient outcomes and survivorship, but also reduced healthcare cost and socio-economic burden. To date, there is insufficient evidence from the literature to suggest whether dementia is the cause or effect for fragility fractures, or if indeed there is a bidirectional relationship between the two conditions. Further studies are required to shed light onto this important clinical topic.

The cytokines and micro-environment of fracture haematoma: Current evidence

Fracture haematoma formation is the first and foremost important stage of fracture healing. It orchestrates the inflammatory and cellular processes leading to the formation of callus and the restoration of the continuity of the bone. Evidence suggests that blocking this initial stage could lead to an impairment of the overall bone healing process. This review aims to analyse the existing evidence of molecular contributions to bone healing within fracture haematoma and to determine the potential to modify the molecular response to fracture in the haematoma with the aim of improving union times. A comprehensive search of literature documenting fracture haematoma cytokine content was performed. Suitable papers according to prespecified criteria were identified and analysed according to Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. A total of 89 manuscripts formed the basis of this analysis. Low oxygen tension, high acidity, and high calcium characterised initially the fracture haematoma micro-environment. In addition, a number of cytokines have been measured with concentrations significantly higher than those found in peripheral circulation. Growth factors have also been isolated, with an observed increase in bone morphogenetic proteins, platelet-derived growth factor, and transforming growth factor. Although molecular modification of fracture haematoma has been attempted, more research is required to determine a suitable biological response modifier leading to therapeutic effects. The cytokine content of fracture haematoma gives insight into processes occurring in the initial stages of fracture healing. Manipulation of signalling molecules represents a promising pathway to target future therapies aiming to upregulate the osteogenesis.

The Effect of Price on Surgeons' Choice of Implants: A Randomized Controlled Survey

PURPOSE

Surgical costs are under scrutiny and surgeons are being held increasingly responsible for cost containment. In some instances, implants are the largest component of total procedure cost, yet previous studies reveal that surgeons' knowledge of implant prices is poor. Our study aims to (1) understand drivers behind implant selection and (2) assess whether educating surgeons about implant costs affects implant selection.

METHODS

We surveyed 226 orthopedic surgeons across 6 continents. The survey presented 8 clinical cases of upper extremity fractures with history, radiographs, and implant options. Surgeons were randomized to receive either a version with each implant's average selling price ("price-aware" group), or a version without prices ("price-naïve" group). Surgeons selected a surgical implant and ranked factors affecting implant choice. Descriptive statistics and univariate, multivariable, and subgroup analyses were performed.

RESULTS

For cases offering implants within the same class (eg, volar locking plates), price-awareness reduced implant cost by 9% to 11%. When offered different models of distal radius volar locking plates, 25% of price-naïve surgeons selected the most expensive plate compared with only 7% of price-aware surgeons. For cases offering different classes of implants (eg, plate vs external fixator), there was no difference in implant choice between price-aware and price-naïve surgeons. Familiarity with the implant was the most common reason for choosing an implant in both groups (35% vs 46%). Price-aware surgeons were more likely to rank cost as a factor (29% vs 21%).

CONCLUSIONS

Price awareness significantly influences surgeons' choice of a specific model within the same implant class. Merely including prices with a list of implants leads surgeons to select less expensive implants. This implies that an untapped opportunity exists to reduce surgical expenditures simply by enhancing surgeons' cost awareness.

TYPE OF STUDY/LEVEL OF EVIDENCE

Economic/Decision Analyses I.

Articular impaction injuries in the lower limb

The effective management of articular impacted fractures requires the successful elevation of the osteochondral fragment to eliminate joint incongruency and the stable fixation of the fragments providing structural support to the articular surface.The anatomical restoration of the joint can be performed either with elevation through a cortical window, through balloon-guided osteoplasty or direct visualisation of the articular surface.Structural support of the void created in the subchondral area can be achieved through the use of bone graft materials (autologous tricortical bone), or synthetic bone graft substitutes.In the present study, we describe the available techniques and materials that can be used in treating impacted osteochondral fragments with special consideration of their epidemiology and treatment options. Cite this article: EFORT Open Rev 2017;2. DOI: 10.1302/2058-5241.2.160072. Originally published online at www.efortopenreviews.org.

Effect of methotrexate on bone and wound healing

INTRODUCTION

Methotrexate (MTX) is one of the most commonly used disease modifying drugs administered for wide spectrum of conditions. Through the expansion of the indications of MTX use, an increasing number of patients nowadays attend orthopaedic departments receiving this pharmacological agent. The aim of this manuscript is to present our current understanding on the effect of MTX on bone and wound healing. Areas covered: The authors offer a comprehensive review of the existing literature on the experimental and clinical studies analysing the effect of MTX on bone and wound healing. The authors also analyse the available literature and describe the incidence of complications after elective orthopaedic surgery in patients receiving MTX. Expert opinion: The available experimental data and clinical evidence are rather inadequate to allow any safe scientific conclusions on the effect of MTX on bone healing. Regarding wound healing, in vitro and experimental animal studies suggest that MTX can adversely affect wound healing, whilst the clinical studies show that lose-dose MTX is safe and does not affect the incidence of postoperative wound complications.

Is there a role of coral bone substitutes in bone repair?

Xenogeneic bone graft materials are an alternative to autologous bone grafting. Among such implants, coralline-derived bone grafts substitutes have a long track record as safe, biocompatible and osteoconductive graft materials. In this review, we present the available literature surrounding their use with special focus on the commercially available graft materials. Corals thanks to their chemical and structural characteristics similar to those of the human cancellous bone have shown great potential but clinical data presented to date is ambiguous with both positive and negative outcomes reported. Correct formulation and design of the graft to ensure adequate osteo-activity and resorption appear intrinsic to a successful outcome.

Interpretation of Post-operative Distal Humerus Radiographs After Internal Fixation: Prediction of Later Loss of Fixation

PURPOSE

Stable fixation of distal humerus fracture fragments is necessary for adequate healing and maintenance of reduction. The purpose of this study was to measure the reliability and accuracy of interpretation of postoperative radiographs to predict which implants will loosen or break after operative treatment of bicolumnar distal humerus fractures. We also addressed agreement among surgeons regarding which fracture fixation will loosen or break and the influence of years in independent practice, location of practice, and so forth.

METHODS

A total of 232 orthopedic residents and surgeons from around the world evaluated 24 anteroposterior and lateral radiographs of distal humerus fractures on a Web-based platform to predict which implants would loosen or break. Agreement among observers was measured using the multi-rater kappa measure.

RESULTS

The sensitivity of prediction of failure of fixation of distal humerus fracture on radiographs was 63%, specificity was 53%, positive predictive value was 36%, the negative predictive value was 78%, and accuracy was 56%. There was fair interobserver agreement (κ = 0.27) regarding predictions of failure of fixation of distal humerus fracture on radiographs. Interobserver variability did not change when assessed for the various subgroups.

CONCLUSIONS

When experienced and skilled surgeons perform fixation of type C distal humerus fracture, the immediate postoperative radiograph is not predictive of fixation failure. Reoperation based on the probability of failure might not be advisable.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic III.

The role of peptides in bone healing and regeneration: a systematic review

BACKGROUND

Bone tissue engineering and the research surrounding peptides has expanded significantly over the last few decades. Several peptides have been shown to support and stimulate the bone healing response and have been proposed as therapeutic vehicles for clinical use. The aim of this comprehensive review is to present the clinical and experimental studies analysing the potential role of peptides for bone healing and bone regeneration.

METHODS

A systematic review according to PRISMA guidelines was conducted. Articles presenting peptides capable of exerting an upregulatory effect on osteoprogenitor cells and bone healing were included in the study.

RESULTS

Based on the available literature, a significant amount of experimental in vitro and in vivo evidence exists. Several peptides were found to upregulate the bone healing response in experimental models and could act as potential candidates for future clinical applications. However, from the available peptides that reached the level of clinical trials, the presented results are limited.

CONCLUSION

Further research is desirable to shed more light into the processes governing the osteoprogenitor cellular responses. With further advances in the field of biomimetic materials and scaffolds, new treatment modalities for bone repair will emerge.

Pharmacological adjuncts to stop bleeding: options and effectiveness

Severe trauma and massive haemorrhage represent the leading cause of death and disability in patients under the age of 45 years in the developed world. Even though much advancement has been made in our understanding of the pathophysiology and management of trauma, outcomes from massive haemorrhage remain poor. This can be partially explained by the development of coagulopathy, acidosis and hypothermia, a pathological process collectively known as the “lethal triad” of trauma. A number of pharmacological adjuncts have been utilised to stop bleeding, with a wide variation in the safety and efficacy profiles. Antifibrinolytic agents in particular, act by inhibiting the conversion of plasminogen to plasmin, therefore decreasing the degree of fibrinolysis. Tranexamic acid, the most commonly used antifibrinolytic agent, has been successfully incorporated into most trauma management protocols effectively reducing mortality and morbidity following trauma. In this review, we discuss the current literature with regard to the management of haemorrhage following trauma, with a special reference to the use of pharmacological adjuncts. Novel insights, concepts and treatment modalities are also discussed.

Cost analysis and outcomes of simple elbow dislocations

AIM: To evaluate the management, clinical outcome and cost implications of three different treatment regimes for simple elbow dislocations.

METHODS: Following institutional board approval, we performed a retrospective review of all consecutive patients treated for simple elbow dislocations in a Level I trauma centre between January 2008 and December 2010. Based on the length of elbow immobilisation (LOI), patients were divided in three groups (Group I, < 2 wk; Group II, 2-3 wk; and Group III, > 3 wk). Outcome was considered satisfactory when a patient could achieve a pain-free range of motion ≥ 100° (from 30° to 130°). The associated direct medical costs for the treatment of each patient were then calculated and analysed.

RESULTS: We identified 80 patients who met the inclusion criteria. Due to loss to follow up, 13 patients were excluded from further analysis, leaving 67 patients for the final analysis. The mean LOI was 14 d (median 15 d; range 3-43 d) with a mean duration of hospital engagement of 67 d (median 57 d; range 10-351 d). Group III (prolonged immobilisation) had a statistically significant worse outcome in comparison to Group I and II (P = 0.04 and P = 0.01 respectively); however, there was no significant difference in the outcome between groups I and II (P = 0.30). No statistically significant difference in the direct medical costs between the groups was identified.

CONCLUSION: The length of elbow immobilization doesn’t influence the medical cost; however immobilisation longer than three weeks is associated with persistent stiffness and a less satisfactory clinical outcome.

Biological and molecular profile of fracture non-union tissue: current insights

Delayed bone healing and non-union occur in approximately 10% of long bone fractures. Despite intense investigations and progress in understanding the processes governing bone healing, the specific pathophysiological characteristics of the local microenvironment leading to non-union remain obscure. The clinical findings and radiographic features remain the two important landmarks of diagnosing non-unions and even when the diagnosis is established there is debate on the ideal timing and mode of intervention. In an attempt to understand better the pathophysiological processes involved in the development of fracture non-union, a number of studies have endeavoured to investigate the biological profile of tissue obtained from the non-union site and analyse any differences or similarities of tissue obtained from different types of non-unions. In the herein study, we present the existing evidence of the biological and molecular profile of fracture non-union tissue.

Mesenchymal Stem Cell physiology can be affected by antibiotics: An in vitro study

The aim of this study was to investigate the effect of antibiotics used in clinical practice on Mesenchymal Stem Cells (MSCs) potential to proliferate and differentiate towards an osteogenic lineage. Trabecular bone was obtained from 10 patients (mean age of 36 years, range 18-72) suffering from long bone fractures. Mesenchymal Stem Cells (MSCs) were isolated and functional assays on their proliferation (CFU-F and XTT) and osteogenic differentiation (alkaline phosphatase activity and total calcium production) were performed. The effect of medium supplementation with gentamicin, vancomycin, benzyl-penicillin, flucloxacillin, cefuroxime and metronidazole was analysed. In concentrations found in peripheral circulation, none of the studies antibiotics had an effect on MSCs ability to proliferate and differentiate towards osteogenic lineage. Vancomycin and gentamicin in concentrations of 200 μg/ml and 75 μg/ml respectively, down-regulated the proliferation and osteogenic activity of MSCs. Some combination of the studied antibiotics found to inhibit both proliferation and osteogenesis. High antibiotic concentrations and the combination of different formulations can have detrimental effects on osteoprogenitor cells physiology and potentially bone healing.

Ability of bone graft substitutes to support the osteoprogenitor cells: An in-vitro study

AIM: To compare seven commercially available bone graft substitutes (BGS) in terms of these properties and without using any additional biological growth factors.

METHODS: Porcine osteoprogenitor cells were loaded on seven commercially available BGS and allowed to proliferate for one week followed by osteogenic induction. Staining for live/dead cells as well as scanning electron microscopy (SEM) was carried out to determine viability and cellular binding. Further outcome measures included alkaline phosphatase (ALP) assays with normalisation for DNA content to quantify osteogenic potential. Negative and positive control experiments were carried out in parallel to validate the results.

RESULTS: Live/dead and SEM imaging showed higher viability and attachment with β-tricalcium phosphate (β-TCP) than with other BGS (P < 0.05). The average ALP activity in nmol/mL (normalised value for DNA content in nmol/μg DNA) per sample was 657.58 (132.03) for β-TCP, 36.22 (unable to normalise) for calcium sulphate, 19.93 (11.39) for the Hydroxyapatite/Tricalcium Phosphate composite, 14.79 (18.53) for polygraft, 13.98 (8.15) for the highly porous β-Tricalcium Phosphate, 5.56 (10.0) for polymers, and 3.82 (3.8) for Hydroxyapatite.

CONCLUSION: Under the above experimental conditions, β-TCP was able to maintain better the viability of osteoprogenitor cells and allow proliferation and differentiation (P < 0.05).

Fracture non-union: Can biomarkers predict outcome?

Delayed bone healing and non-union occurs in approximately 10-15% of long bone fractures. Both pathologies may result in prolonged period of pain, disability and repetitive operative interventions. Despite intense investigations and progress done in understanding the pathophysiologic processes governing bone healing, the diagnostic tools have not been altered. The clinical findings and radiographic features remain the two important landmarks of diagnosing non-union and even when the diagnosis is established there is debate on the ideal timing and mode of intervention. Emerging evidence suggest that there are certain molecules and genes that can serve as predictors of potentially unsuccessful fracture union. This article summarises the current evidence on the available 'bio-markers'to predict fracture non-union.

Release of growth factors and the effect of age, sex, and severity of injury after long bone fracture. A preliminary report

BACKGROUND AND PURPOSE

The systemic response after fracture is regulated by a complex mechanism involving numerous growth factors. In this study, we analyzed the kinetics of key growth factors following lower-limb long bone fracture.

MATERIALS AND METHODS

Human serum was isolated from 15 patients suffering from lower-limb long bone fracture (tibia/femur) requiring surgical fixation. The levels of platelet-derived growth factor (PDGF-BB), vascular edothelial growth factor (VEGF), insulin growth factor-I (IGF-I), and transforming growth factor β1 (TGF-β1) were assayed by colorimetric ELISA at different time points during the first week after fracture. 10 healthy volunteers made up the control group of the study. Serum levels of the growth factors measured were compared to age, sex, and injury severity score.

RESULTS

We found that there was a decline in the levels of PDGF-BB, IGF-I and TGF-β1 during the first 3 days after fracture. However, VEGF levels remained unchanged. The levels of all the growth factors studied then increased, with the highest concentrations noted at day 7 after surgery. No correlation was found between circulating levels of growth factors and age, injury severity score (ISS), blood loss, or fluid administration.

INTERPRETATION

There are systemic mitogenic and osteogenic signals after fracture. Important growth factors are released into the peripheral circulation, but early after surgery it appears that serum levels of key growth factors fall. By 7 days postoperatively, the levels had increased considerably. Our findings should be considered in cases where autologous serum is used for ex vivo expansion of mesenchymal stem cells. There should be further evaluation of the use of these molecules as biomarkers of bone union.

Do nonsteroidal anti-inflammatory drugs affect bone healing? A critical analysis

Nonsteroidal anti-inflammatory drugs (NSAIDs) play an essential part in our approach to control pain in the posttraumatic setting. Over the last decades, several studies suggested that NSAIDs interfere with bone healing while others contradict these findings. Although their analgesic potency is well proven, clinicians remain puzzled over the potential safety issues. We have systematically reviewed the available literature, analyzing and presenting the available in vitro animal and clinical studies on this field. Our comprehensive review reveals the great diversity of the presented data in all groups of studies. Animal and in vitro studies present so conflicting data that even studies with identical parameters have opposing results. Basic science research defining the exact mechanism with which NSAIDs could interfere with bone cells and also the conduction of well-randomized prospective clinical trials are warranted. In the absence of robust clinical or scientific evidence, clinicians should treat NSAIDs as a risk factor for bone healing impairment, and their administration should be avoided in high-risk patients.

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

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

The effect of autologous serum obtained after fracture on the proliferation and osteogenic differentiation of mesenchymal stem cells

The purpose of this study was to investigate the potential of Mesenchymal Stem Cells (MSCs) obtained from patients suffering from fractures to proliferate and differentiate towards osteogenic lineage with the use of autologous serum. In addition the effect of medium supplementation with the use of autologous serum obtained at different time points (patients' admission, first, third and seventh post-operative day) was investigated. In total eight patients suffering from lower limb long bone fractures with mean age of 39 (range 22-68 years) were included in this study. MSCs were isolated and cultivated in 10% of either Fetal Calf Serum (FCS) or autologous serum. Cellular proliferation was examined by XTT assay and Vybrant assay. The osteogenic differentiation was assessed by total calcium production and alkaline phosphatase production. Cellular proliferation and osteogenic differentiation was significantly statistically higher in patients' serum obtained on admission than in FCS. A negative effect on proliferation was noted with serum obtained on the first postoperative day. Subsequently, both proliferation and differentiation were gradually increased with autologous serum collected during the 3rd and 7th postoperatively days. Autologous serum obtained after fracture is superior in terms of proliferation and osteogenic differentiation to the currently used FCS. Surgery seems to have a negative effect on the quality of serum. These findings should be considered in cases where ex-vivo expansion of MSCs is needed. Recuperation of serum's quality takes place at a later time point within the first weeks after fracture.

Growth factor release following femoral nailing

The aim of this study was to investigate whether growth factors essential for fracture healing are substantially increased in the immediate aftermath following reaming of the intramedullary cavity for stabilisation of femoral shaft fractures. Consecutive adult patients whose femoral shaft fractures stabilised with either reamed (10 patients) or unreamed (10 patients) intramedullary nailing were studied. Peripheral blood samples and samples from the femoral canal before and after reaming and nail insertion were collected. Serum was extracted and using Elisa colorimetric assays the concentration of Platelet Derived Growth Factor-BetaBeta (PDGF), Vascular Endothelial Growth Factor (VEGF), Insulin-like Growth Factor-I (IGF-I), Transforming Growth Factor beta 1 (TGF-beta1) and Bone Morphogenetic Protein-2 (BMP-2) was measured. The mean age of the twenty patients who participated in the study was 38 years (range 20-63). Reaming substantially increased all studied growth factors (p<0.05) locally in the femoral canal. VEGF and PDGF were increased after reaming by 111.2% and 115.6% respectively. IGF-I was increased by 31.5% and TGF-beta1 was increased by 54.2%. In the unreamed group the levels of PDGF-BB, VEGF, TGF-beta1 remained unchanged while the levels of IGF-I decreased by 10%. The levels of these mediators in the peripheral circulation were not altered irrespectively of the nail insertion technique used. BMP-2 levels during all time points were below the detection limit of the immunoassay. This study indicates that reaming of the intramedullary cavity is associated with increased liberation of growth factors. The osteogenic effect of reaming could be secondary not only to grafting debris but also to the increased liberation of these molecules.

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

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

Mesenchymal stem cell tissue engineering: techniques for isolation, expansion and application

Mesenchymal stem cells (MSCs) are undifferentiated multipotent cells which reside in various human tissues and have the potential to differentiate into osteoblasts, chondrocytes, adipocytes, fibroblasts and other tissues of mesenchymal origin. In the human body they could be regarded as readily available reservoirs of reparative cells capable to mobilize, proliferate and differentiate to the appropriate cell type in response to certain signals. These properties have triggered a variety of MSC-based therapies for pathologies including nonunions, osteogenesis imperfecta, cartilage damage and myocardial infarction. The outcome of these approaches is influenced by the methodologies and materials used during the cycle from the isolation of MSCs to their re-implantation. This review article focuses on the pathways that are followed from the isolation of MSCs, expansion and implantation.

Safety and efficacy of vena cava filters in trauma patients

Pulmonary embolism (PE), due to its sudden onset, notoriously difficult diagnosis, unpredictable nature and often fatal outcome, remains one of the most feared complications in surgical practice. Trauma patients with multisystem injuries, extremity or pelvic fractures and head or spinal cord injuries often pose a significant dilemma for the surgeon because of the inability to use conventional measures such as anticoagulation therapy and compression devices. On the other hand, the incidence of deep vein thrombosis (DVT) is high among trauma patients and the attendant risk of PE is an important cause of morbidity and mortality. Inferior vena cava (IVC) interruption by placement of diverse filtering devices has evolved over the past three decades. With the use of these devices, the risk of PE has been reduced dramatically. However, variable rates of complications are reported from their use. In this study, we review all the available data on IVC filter placement in trauma patients and we discuss the potential complications of IVC filters in order to understand better the risk/benefit ratio of their use.

Tissue regeneration. The past, the present and the future

Tissue engineering has been a topic of extensive research over the last years. The ability of human body to regenerate tissue loss such as bone, cartilage, nerves, skin and muscle is limited leading often to amputations of limbs or functional disability. The isolation of mesenchymal stem cells (MSCs) and later the embryonic stem cells in conjunction with the advances made in cellular biology, tissue engineering, genetics and recombinant technology has initiated the development of new techniques and new therapeutic strategies allowing treatment of many pathological conditions providing restoration of tissue continuity and function.

Biology of mesenchymal stem cells

Mesenchymal stem cells are present in many human tissues and serve as a readily available source of undifferentiated cells being capable to form specific tissues like bone, cartilage, fat, muscle and tendon. They represent an attractive and promising field in tissue regeneration and engineering for treatment applications in a wide range of trauma and orthopaedic conditions. This article covers the most important aspects of recent research data demonstrating the combination of physiological properties of mesenchymal stem cells (MSCs) and applications in the clinical setting.