The ‘diamond concept’ for long bone non-union management

Long bone non-union continues to be a significant worldwide problem. Since its inception over a decade ago, the ‘diamond concept’, a conceptual framework of what is essential for a successful bone healing response, has gained great acceptance for assessing and planning the management of fracture non-unions. Herein, we discuss the epidemiology of non-unions, the basic science of bone healing in the context of the diamond concept, the currently available results and areas for future research

Induced periosteum-mimicking membrane with cell barrier and multipotential stromal cell (MSC) homing functionalities

The current management of critical size bone defects (CSBDs) remains challenging and requires multiple surgeries. To reduce the number of surgeries, wrapping a biodegradable fibrous membrane around the defect to contain the graft and carry biological stimulants for repair is highly desirable. Poly(ε-caprolactone) (PCL) can be utilised to realise nonwoven fibrous barrier-like structures through free surface electrospinning (FSE). Human periosteum and induced membrane (IM) samples informed the development of an FSE membrane to support platelet lysate (PL) absorption, multipotential stromal cells (MSC) growth, and the prevention of cell migration. Although thinner than IM, periosteum presented a more mature vascular system with a significantly larger blood vessel diameter. The electrospun membrane (PCL3%-E) exhibited randomly configured nanoscale fibres that were successfully customised to introduce pores of increased diameter, without compromising tensile properties. Additional to the PL absorption and release capabilities needed for MSC attraction and growth, PCL3%-E also provided a favourable surface for the proliferation and alignment of periosteum- and bone marrow derived-MSCs, whilst possessing a barrier function to cell migration. These results demonstrate the development of a promising biodegradable barrier membrane enabling PL release and MSC colonisation, two key functionalities needed for the in situ formation of a transitional periosteum-like structure, enabling movement towards single-surgery CSBD reconstruction

Enrichment and preserved functionality of multipotential stromal cells in bone marrow concentrate processed by vertical centrifugation

The concentration of bone marrow (BM) aspirate (BMA) is increasingly valued for bone and cartilage repair, particularly with the rarity and donor-variability of BM-multipotential stromal cells (BM-MSCs). The present study aimed to assess BM-MSC yield following BM concentration using a fast and compact-sized vertical centrifugation system. BMA concentrate (BMAC) was separated in a 1 min process and collected easily after an automatic discarding of plasma and red blood cells. A significant increase in CD45low CD271high cells per BMAC volume (measured using flow-cytometry) was noted (4-fold, p = 0.0001). Additionally, the vertical centrifugation system helped to enrich colony numbers (assessed by CFU-F assays) in BMAC comparably with conventional centrifugation systems, BioCUE™ and SmartPReP-2® (4.3-fold, 4.6-fold and 3-fold, respectively). Next, a functional assessment of BM-MSCs processed by vertical centrifugation was performed, and MSC viability and proliferation were not affected. Also, these BM-MSCs showed similar alkaline phosphatase and calcium levels to those of BMA-MSCs when osteogenically induced. Furthermore, glycosaminoglycans and Nile red levels in addition to the gene expression assays confirmed that there was no significant change in chondrogenic or adipogenic abilities between BMA-MSCs and BMAC-MSCs. The expression levels of selected angiogenic and immunomodulatory mediators were also similar between the two groups. Collectively, the vertical centrifugation system helped to enrich BM-MSCs effectively, while maintaining cell viability and functions. Thus, such a vertical centrifugation system for BM concentration can be valuable for various regenerative therapies

Timing of major fracture care in polytrauma patients – an update on principles, parameters and strategies for 2020

Objectives Sustained changes in resuscitation and transfusion management have been observed since the turn of the millennium, along with an ongoing discussion of surgical management strategies. The aims of this study are threefold: a) to evaluate the objective changes in resuscitation and mass transfusion protocols undertaken in major level I trauma centers; b) to summarize the improvements in diagnostic options for early risk profiling in multiply injured patients and c) to assess the improvements in surgical treatment for acute major fractures in the multiply injured patient. Methods I. A systematic review of the literature (comprehensive search of the MEDLINE, Embase, PubMed, and Cochrane Central Register of Controlled Trials databases) and a concomitant data base (from a single Level I center) analysis were performed. Two authors independently extracted data using a pre-designed form. A pooled analysis was performed to determine the changes in the management of polytraumatized patients after the change of the millennium. II. A data base from a level I trauma center was utilized to test any effects of treatment changes on outcome. Inclusion criteria: adult patients, ISS > 16, admission < less than 24 h post trauma. Exclusion: Oncological diseases, genetic disorders that affect the musculoskeletal system. Parameters evaluated were mortality, ICU stay, ICU complications (Sepsis, Pneumonia, Multiple organ failure). Results I. From the electronic databases, 5141 articles were deemed to be relevant. 169 articles met the inclusion criteria and a manual review of reference lists of key articles identified an additional 22 articles. II. Out of 3668 patients, 2694 (73.4%) were male, the mean ISS was 28.2 (SD 15.1), mean NISS was 37.2 points (SD 17.4 points) and the average length of stay was 17.0 days (SD 18.7 days) with a mean length of ICU stay of 8.2 days (SD 10.5 days), and a mean ventilation time of 5.1 days (SD 8.1 days). Both surgical management and nonsurgical strategies have changed over time. Damage control resuscitation, dynamic analyses of coagulopathy and lactate clearance proved to sharpen the view of the worsening trauma patient and facilitated the prevention of further complications. The subsequent surgical care has become safer and more balanced, avoiding overzealous initial surgeries, while performing early fixation, when patients are physiologically stable or rapidly improving. Severe chest trauma and soft tissue injuries require further evaluation. Conclusions Multiple changes in management (resuscitation, transfusion protocols and balanced surgical care) have taken place. Moreover, improvement in mortality rates and complications associated with several factors were also observed. These findings support the view that the management of polytrauma patients has been substantially improved over the past 3 decades

Bone marrow multipotent mesenchymal stromal cells as autologous therapy for osteonecrosis: effects of age and underlying causes

Bone marrow (BM) is a reliable source of multipotent mesenchymal stromal cells (MSCs), which have been successfully used for treating osteonecrosis. Considering the functional advantages of BM-MSCs as bone and cartilage reparatory cells and supporting angiogenesis, several donor-related factors are also essential to consider when autologous BM-MSCs are used for such regenerative therapies. Aging is one of several factors contributing to the donor-related variability and found to be associated with a reduction of BM-MSC numbers. However, even within the same age group, other factors affecting MSC quantity and function remain incompletely understood. For patients with osteonecrosis, several underlying factors have been linked to the decrease of the proliferation of BM-MSCs as well as the impairment of their differentiation, migration, angiogenesis-support and immunoregulatory functions. This review discusses the quality and quantity of BM-MSCs in relation to the etiological conditions of osteonecrosis such as sickle cell disease, Gaucher disease, alcohol, corticosteroids, Systemic Lupus Erythematosus, diabetes, chronic renal disease and chemotherapy. A clear understanding of the regenerative potential of BM-MSCs is essential to optimize the cellular therapy of osteonecrosis and other bone damage conditions

Implementation of a standardized protocol to manage elderly patients with low energy pelvic fractures: can service improvement be expected?

Purpose: The incidence of low energy pelvic fractures (FPFs) in the elderly is increasing. Comorbidities, decreased bone-quality, problematic fracture fixation and poor compliance represent some of their specific difficulties. In the absence of uniform management, a standard operating procedure (SOP) was introduced to our unit, aiming to improve the quality of services provided to these patients. Methods: A cohort study was contacted to test the impact of (1) using a specific clinical algorithm and (2) using different antiosteoporotic drugs. Multivariate regression analysis was used to determine prognostic factors. Study endpoints were the time-to-healing, length-of-stay, return to pre-injury mobility, union status, mortality and complications. Results: A total of 132 elderly patients (≥65 years) admitted during the period 2012–2014 with FPFs were enrolled. High-energy fractures, acetabular fractures, associated trauma affecting mobility, pathological pelvic lesions and operated FPFs were used as exclusion criteria. The majority of included patients were females (108/132; 81.8%), and the mean age was 85.8 years (range 67–108). Use of antiosteoporotics was associated with a shorter time of healing (p = 0.036). Patients treated according to the algorithm showed a significant protection against malunion (p < 0.001). Also, adherence to the algorithm allowed more patients to return to their pre-injury mobility status (p = 0.039). Conclusions: The use of antiosteoporotic medication in elderly patients with fragility pelvic fractures was associated with faster healing, whilst the adherence to a structured clinical pathway led to less malunions and non-unions and return to pre-injury mobility state

Regulation of Angiogenesis Discriminates Tissue Resident MSCs from Effective and Defective Osteogenic Environments

[Abstract] Background: The biological mechanisms that contribute to atrophic long bone non-union are poorly understood. Multipotential mesenchymal stromal cells (MSCs) are key contributors to bone formation and are recognised as important mediators of blood vessel formation. This study examines the role of MSCs in tissue formation at the site of atrophic non-union. Materials and Methods: Tissue and MSCs from non-union sites (n = 20) and induced periosteal (IP) membrane formed following the Masquelet bone reconstruction technique (n = 15) or bone marrow (n = 8) were compared. MSC content, differentiation, and influence on angiogenesis were measured in vitro. Cell content and vasculature measurements were performed by flow cytometry and histology, and gene expression was measured by quantitative polymerase chain reaction (qPCR). Results: MSCs from non-union sites had comparable differentiation potential to bone marrow MSCs. Compared with induced periosteum, non-union tissue contained similar proportion of colony-forming cells, but a greater proportion of pericytes (p = 0.036), and endothelial cells (p = 0.016) and blood vessels were more numerous (p = 0.001) with smaller luminal diameter (p = 0.046). MSCs showed marked differences in angiogenic transcripts depending on the source, and those from induced periosteum, but not non-union tissue, inhibited early stages of in vitro angiogenesis. Conclusions: In vitro, non-union site derived MSCs have no impairment of differentiation capacity, but they differ from IP-derived MSCs in mediating angiogenesis. Local MSCs may thus be strongly implicated in the formation of the immature vascular network at the non-union site. Attention should be given to their angiogenic support profile when selecting MSCs for regenerative therapy

Evaluation of human bone marrow mesenchymal stromal cell (MSC) functions on a biomorphic rattan-wood-derived scaffold: a comparison between cultured and uncultured MSCs

The reconstruction of large bone defects requires the use of biocompatible osteoconductive scaffolds. These scaffolds are often loaded with the patient’s own bone marrow (BM) cells to facilitate osteoinductivity and biological potency. Scaffolds that are naturally sourced and fabricated through biomorphic transitions of rattan wood (B-HA scaffolds) offer a unique advantage of higher mechanical strength and bioactivity. In this study, we investigated the ability of a biomorphic B-HA scaffold (B-HA) to support the attachment, survival and gene expression profile of human uncultured BM-derived mesenchymal stromal cells (BMSCs, n = 6) and culture expanded MSCs (cMSCs, n = 7) in comparison to a sintered, porous HA scaffold (S-HA). B-HA scaffolds supported BMSC attachment (average 98%) and their survival up to 4 weeks in culture. Flow cytometry confirmed the phenotype of cMSCs on the scaffolds. Gene expression indicated clear segregation between cMSCs and BMSCs with MSC osteogenesis- and adipogenesis-related genes including RUNX2, PPARγ, ALP and FABP4 being higher expressed in BMSCs. These data indicated a unique transcriptional signature of BMSCs that was distinct from that of cMSCs regardless of the type of scaffold or time in culture. There was no statistical difference in the expression of osteogenic genes in BMSCs or cMSCs in B-HA compared to S-HA. VEGF release from cMSCs co-cultured with human endothelial cells (n = 4) on B-HA scaffolds suggested significantly higher supernatant concentration with endothelial cells on day 14. This indicated a potential mechanism for providing vasculature to the repair area when such scaffolds are used for treating large bone defects