Objectives. Fracture non-union poses a significant challenge to treating orthopaedic surgeons. These patients often require multiple surgical procedures. The incidence of complications after Autologous Bone Graft (ABG) harvesting has been reported up to 44%. These complications include persistent severe donor site pain, infection, heterotopic ossification and antalgic gait. We retrospectively compared the use of BMP-7 alone in long bone fracture Non-union, with patients in whom BMP-7 was used in combination with the Autologous Bone Graft (ABG). Material and Methods. The databases of our dedicated Limb Reconstruction Unit were searched for patient with three common long bone fractures Non-unions (Tibia, Femur and Humerus). The patients who had intra-operative use of Bone Morphogenetic Protein (BMP-7) alone and in combination with ABG were evaluated. 53 Patients had combined use of ABG and BMP-7, and 65 patients had BMP-7 alone. Results. In the ABG and BMP-7 group, the union rate for femoral (n=18) Non-unions was 83%, for humeral (n=16) Non-unions 81%, and for tibia (n=19) Non-unions it was 47%. In the BMP-7 alone group, 83% of the femoral (n=12) Non-unions, 87% of the humeral (n=16) and 56% of the tibial (n=37) Non-unions healed. The common risk factors for Non-union were comparable in both the groups and included location and nature (open vs closed) of fracture, infection, smoking and NSAIDs use. The average time to union in ABG+BMP-7 group was 8.1 months (range 3-30 months) and in BMP-7 alone group it was 7.2 months (range 3-24 months). Conclusion. Autologous Bone Grafting has a pivotal role in limb reconstruction surgery but its indication should be carefully evaluated in view of considerable morbidity associated with graft donor site. Our study did not show any significant difference in the union rates of common long bone fracture Non-unions treated with BMP-7 alone or with a combination of Autologous Bone Graft and BMP-7

The optimal treatment strategy for post-traumatic long bone non-unions is subject of an ongoing discussion. At the Maastricht University Medical Center (MUMC+) the induced membrane technique is used to treat post-traumatic long bone non-unions. This technique uses a multimodal treatment algorithm involving bone marrow aspirate concentrate (BMAC), the reamer-irrigator-aspirator (RIA) and P-15 bioactive peptide (iFactor, Cerapedics). Bioactive glass (S53P4 BAG, Bonalive) is added when infection is suspected. This study aims to objectify the effect of this treatment algorithm on the health-related quality of life (HRQoL) of patients with post-traumatic long bone non-unions. We hypothesized that HRQoL would improve after treatment. From January 2020 to March 2023, consecutive patients who were referred to a multidisciplinary (trauma, orthopaedic and plastic surgery) non-union clinic at the MUMC+, The Netherlands, were evaluated using the Non-Union Scoring System (NUSS). The EQ-5D-5L questionnaire and the Lower Extremity Functional Scale (LEFS) were employed to obtain HRQoL outcomes both prior to and subsequent to surgery, with a follow-up at 6, 18 and 35 weeks. Seventy-six patients were assessed at baseline (T0), with a mean NUSS of 40 (± 13 SD). Thirty-eight patients had their first follow-up, six weeks after surgery (T1). Thirty-one patients had a second follow-up at 18 weeks (T2), and twenty patients had the third follow-up at 35 weeks (T3). The EQ-5D index mean at baseline was 0.480, followed by an index of 0.618 at T1, 0.636 at T2, and 0.702 at T3. A significant difference was found in the HRQoL score between T0 and T1, as well as T2 and T3 (p<0.001; p=0.011). The mean LEFS significantly increased from 26 before intervention to 34, 39, and 43 after treatment (p<0.001; p=0.033; p=0.016). This study demonstrated a significant improvement in the health-related quality of life of patients with post-traumatic long bone non-unions after the standardized treatment algorithm following the induced membrane technique

Introduction. The non-union of long bones poses a substantial challenge to clinicians and patients alike. The Ilizarov fixation system and Limb Reconstruction System (LRS), renowned for their versatility in managing complex non-unions. The purpose of this retrospective study was to assess the outcomes of acute docking with the bone peg-in-bone technique for the management of non-unions of long bones. The study seeks to evaluate its effectiveness in achieving complete bony union, preserving limb length and alignment, correcting existing deformities, and preventing the onset of new ones. Method. A retrospective analysis of 42 patients was done with infected and non-infected non-unions of long bones who received treatment at a tertiary care hospital between April 2016 to April 2022. We utilized the Association for the Study and Application of Methods of the Ilizarov (ASAMI) scoring system to assess both bone and functional outcomes and measured mechanical lateral distal femoral angle (mLDFA) for the femur and the medial proximal tibial angle (MPTA) for the tibia. Result. In our retrospective study involving 42 patients, a total of 30 patients had post debridement gap of >2 cm and average gap of 4.54 cm (range 1 – 13 cm) and therefore underwent corticotomy and lengthening. The average external fixation time was 6.52 (range 4 – 11 months) and average external fixation index of 2.08 (range 0.4 – 4.5 months/cm). The ASAMI scoring system showed bone result of 38 excellent, 3 good and 1 fair. Functional result of 40 excellent and 2 good outcomes. The post op mLDFA and MPTA were in normal range except in 3 patients which not statistically significant. Conclusion. In conclusion, the use of acute docking provides several advantages such as promoting early fracture healing, increasing stability, shortening treatment time, reducing the number of surgical procedures and reduced number of complications

Various technical tips have been described on the placement of poller screws during intramedullary nailing however studies reporting outcomes are limited. Overall, there is no consistent conclusion about whether intramedullary nailing alone, or intramedullary nails augmented with poller screws is more advantageous. In a systematic review, we asked: (1) What is the proportion of non-unions with poller screw usage? (2) What is the proportion of malalignment, infection and secondary surgical procedures with poller screws usage?. We conducted a systematic review of multiple databases including Pubmed, EMBASE, and the Cochrane Library. Seventy-four records were identified, twelve met our inclusion criteria. Twelve studies with a total of 348 participants and 353 fractures were included. Mean follow up time was 21.4 months and mean age of included patients was 40.1 year. Seven studies had heterogenous population of non-unions and/ or malunions in addition to acute fractures. Three studies included only acute fractures and two studies examined non unions only. Four of the twelve studies reported non unions with an overall outcome proportion of 4%. Six studies reported coronal malalignment with an overall outcome proportion of 6%. The secondary surgical procedures rate ranged from 2 – 40% with an overall outcome proportion of 8% and included grafting, revisions and any reported cases of removal of metal work. When compared with existing literature our review suggests intramedullary nailing with poller screws has lower rates of non-unions and coronal malalignment than those reported in the literature for intramedullary nailing alone. Prospective randomized control trial is necessary to fully determine outcome benefits

A promising application of Mesenchymal stem cells (MSCs) is the treatment of non-unions. Substituting bone grafts, MSCs are directly injected into the fracture gap. High cell viability seems to be a prerequisite for therapeutic success. Administration of the MSCs via injection creates shear stresses possibly damaging or destroying the cells. Aim of this study was to investigate the effect of the injection process on cell viability. MSCs were isolated and cultivated from femoral tissue of five subjects undergoing arthroplasty. Prior to injection, the cells were identified as MSCs. After dissolving to a concentration of 1 Million cells/ml, 1 ml of the suspension was injected through a cannula of 200 mm length and 2 mm diameter (14 G) with flow rates of 38 and 100 ml/min. The viability of the MSCs at different flow rates was evaluated by staining to detect the healthy cell fraction. It was analyzed statistically against a control group via the Kruskal-Wallis-test and for equivalence via the TOST procedure. Significance level was set to 5 %, equivalence margin to 20 %. The healthy cell fraction of the control group was 85.88 ± 2.98 %, 86.04 ± 2.53 % at 38 ml/min and 85.48 ± 1.64 % at 100 ml/min. There was no significant difference between the fraction of healthy cells (p = 0.99) for different volume flows, but a significant equivalence between the control group and the two volume flows (38 ml/min: p = 0.002, 100 ml/min: p = 0.001). When injecting MSC solutions, e.g. into a non-union, the viability of the injected cells does not deterioriate significant. The injecting technique is therefore feasible

Introduction and Objective. Management of gap non-union of the tibia, the major weight bearing bone of the leg remains controversial. The different internal fixation techniques are often weighed down by relatively high complication rates that include fractures which fail to heal (non-union). Minimally invasive techniques with ring fixators and bone transport (distraction osteogenesis) have come into picture as an alternative allowing alignment and stabilization, avoiding a graduated approach. This study was focused on fractures that result in a gap non-union of > 6 cm. Ilizarov technique was employed for management of such non-unions in this case series. The Ilizarov apparatus consists of rings, rods and kirschner wires that encloses the limb as a cylinder and uses kirschner wires to create tension allowing early weight bearing and stimulating bone growth. Ilizarov technique works on the principle of distraction osteogenesis, that is, pulling apart of bone to stimulate new bone growth. Usually, 4–5 rings are used in the setup depending on fracture site and pattern for stable fixation. In this study, we demonstrate effective bone transport and formation of gap non-union more than 6 cm in 10 patients using only 3 rings construct Ilizarov apparatus. Materials and Methods. This case study was conducted at Dr. D. Y. Patil Medical Hospital, Navi Mumbai, Maharashtra, India. The study involved 10 patients with a non-union or gap > 6 cm after tibial fracture. 3 rings were used in the setup for the treatment of all the patients. Wires were passed percutaneously through the bone using a drill and the projecting ends of the wires were attached to the metal rings and tensioned to increase stability. The outcome of the study was measured using the Oxford Knee scoring system, Functional Mobility Scale, the American Foot and Ankle Score and Visual Analog Scale. Further, follow up of patients was done upto 2 years. Results. All the patients demonstrated good fixation as was assessed clinically and radiologically. 9 patients had a clinical score of > 65 which implied fair to excellent clinical rating. The patients showed good range of motion and were highly satisfied with the treatment as measured by different scoring parameters. Conclusions. In this case study, we demonstrate that the Ilizarov technique using 3 rings is equally effective in treating non-unions > 6 cm as when using 4–5 rings. Obtaining good clinical outcome and low complication rate in all 10 patients shows that this modified technique can be employed for patients with such difficulties in the future

In chronically infected fracture non-unions, treatment requires extensive debridement to remove necrotic and infected bone, often resulting in large defects requiring elaborate and prolonged bone reconstruction. One approach includes the induced membrane technique (IMT), although the differences in outcome between infected and non-infectious aetiologies remain unclear. Here we present a new rabbit humerus model for IMT secondary to infection, and, furthermore, we compare bone healing in rabbits with a chronically infected non-union compared to non-infected equivalents. A 5 mm defect was created in the humerus and filled with a polymethylmethacrylate (PMMA) spacer or left empty (n=6 per group). After 3 weeks, the PMMA spacer was replaced with a beta-tricalcium phosphate (chronOs, Synthes) scaffold, which was placed within the induced membrane and observed for a further 10 weeks. The same protocol was followed for the infected group, except that four week prior to treatment, the wound was inoculated with Staphylococcus aureus (4×10. 6. CFU/animal) and the PMMA spacer was loaded with gentamicin, and systemic therapy was applied for 4 weeks prior to chronOs application. All the animals from the infected group were culture positive during the first revision surgery (mean 3×10. 5. CFU/animal, n= 12), while at the second revision, after antibiotic therapy, all the animals were culture negative. The differences in bone healing between the non-infected and infected groups were evaluated by radiography and histology. The initially infected animals showed impaired bone healing at euthanasia, and some remnants of bacteria in histology. The non-infected animals reached bone bridging in both empty and chronOs conditions. We developed a preclinical in vivo model to investigate how bacterial infection influence bone healing in large defects with the future aim to explore new treatment concepts of infected non-union

Fragility ankles fractures in the geriatric population are challenging to manage, due to fracture instability, soft tissue compromise, patient co-morbidities. Traditional management options include open reduction internal fixation, or conservative treatment, both of which are fraught with high complication rates. We aimed to present functional outcomes of elderly patients with fragility ankle fractures treated with tibiotalocalcaneal nails. 171 patients received a tibiotalocalcaneal nail over a six-year period, but only twenty met the inclusion criteria of being over sixty and having poor bone stock, verified by radiological evidence of osteopenia or history of fragility fractures. Primary outcome was mortality risk from co-morbidities, according to the Charlson co-morbidity index (CCI), and patients’ post-operative mobility status compared to pre-operative mobility. Secondary outcomes include intra-operative and post-operative complications, six-month mortality rate, time to mobilisation and union. The mean age was 77.82 years old, five of whom are type 2 diabetics. The average CCI was 5.05. Thirteen patients returned to their pre-operative mobility state. Patients with low CCI are more likely to return to pre-operative mobility status (p=0.16; OR=4.00). Average time to bone union and mobilisation were 92.5 days and 7.63 days, respectively. Mean post-operative AOFAS ankle-hindfoot and Olerud-Molander scores were 53.0 (range 17-88) and 50.9 (range 20-85), respectively. There were four cases of broken distal locking screws, and four cases of superficial infection. Patients with high CCI were more likely to acquire superficial infections (p=0.264, OR=3.857). There were no deep infections, periprosthetic fractures, nail breakages, non-unions. TTC nailing is an effective treatment methodology for low-demand geriatric patients with fragility ankle fractures. This technique leads to low complication rates and early mobilisation. It is not a life-changing procedure, with many able to return to their pre-operative mobility status, which is important for preventing the loss of socioeconomic independence

Objectives. Pilon fractures represent one of the most surgically challenging fractures in orthopaedics. Different techniques exist for their management, with open reduction and internal fixation (ORIF) and External fixation (Ex-Fix) the most widely used. Whilst there is a plethora of data regarding these strategies for Pilon fractures as a whole, very limited data exists solely on the management of open Pilon fractures. This study aimed to elucidate how surgical management options can influence postoperative complications, and if this can influence future management protocols. Materials and methods. We conducted a search in PubMed, EMBASE and CENTRAL for postoperative complications and functional outcomes in open pilon fractures in those treated with Ex-Fix vs ORIF (PROSPERO-CRD42020184213). The postoperative complications measured included non-union, mal-union, delayed union, bone grafting, amputation, osteoarthritis, deep infection and superficial infection. Functional outcomes in the form of the AOFAS score was also measured where possible. We were able to carry out a meta-analysis for both deep infections and non-unions. Results. The search yielded 309 results and a total of 18 studies consisting of 484 patients were included. All fractures included were open, and consisted of 64 Gustilo-Anderson Type I, 148 Type II, 103 Type IIIa, 90 Type IIIb and 9 Type IIIc. 60 Type III fractures could not be further separated and 12 were ungraded. Both ORIF and Ex-Fix were found to have statistically similar AOFAS scores (p=0.682). For all included studies, the Ex-Fix group had significantly higher rates of superficial infections (p=0.001), non-unions (p=0.001), osteoarthritis (p=0.001) and bone grafting (p=0.001). The meta-analysis found no significant difference in non-union (pooled OR=0.25, 95% CI: 0.03 to 2.24, p = 0.44) or deep infection rates (pooled OR=1.35, 95% CI: 0.11 to 16.69, p = 0.12) between the ORIF and Ex-fix groups. Conclusion. Based on our study, while Ex-Fix and ORIF have similar functional outcomes, Ex-Fix appears to have a significantly higher risk of postoperative complications which must be considered by surgeons when choosing surgical management options. Further research, ideally in a randomised control trial format, is required to definitively demonstrate ORIF superiority in the management of open pilon fractures

Coronoid fractures account for 2 to 15% of the cases with elbow dislocations and usually occur as part of complex injuries. Comminuted fractures and non-unions necessitate coronoid fixation, reconstruction or replacement. The aim of this biomechanical study was to compare the axial stability achieved via an individualized 3D printed prosthesis with curved cemented intramedullary stem to both radial head grafted reconstruction and coronoid fixation with 2 screws. It was hypothesized that the prosthetic replacement will provide superior stability over the grafted reconstruction and screw fixation. Following CT scanning, 18 human cadaveric proximal ulnas were osteotomized at 40% of the coronoid height and randomized to 3 groups (n = 6). The specimens in Group 1 were treated with an individually designed 3D printed stainless steel coronoid prosthesis with curved cemented intramedullary stem, individually designed based on the contralateral coronoid scan. The ulnas in Group 2 were reconstructed with an ipsilateral radial head autograft fixed with two anteroposterior screws, whereas the osteotomized coronoids in Group 3 were fixed in situ with two anteroposterior screws. All specimens were biomechanically tested under ramped quasi-static axial loading to failure at a rate of 10 mm/min. Construct stiffness and failure load were calculated. Statistical analysis was performed at a level of significance set at 0.05. Prosthetic treatment (Group 1) resulted in significantly higher stiffness and failure load compared to both radial head autograft reconstruction (Group 2) and coronoid screw fixation, p ≤ 0.002. Stiffness and failure load did not reveal any significant differences between Group 2 and Group 3, p ≥ 0.846. In cases of coronoid deficiency, replacement of the coronoid process with an anatomically shaped individually designed 3D printed prosthesis with a curved cemented intramedullary stem seems to be an effective method to restore the buttress function of the coronoid under axial loading. This method provides superior stability over both radial head graft reconstruction and coronoid screw fixation, while achieving anatomical articular congruity. Therefore, better load distribution with less stress at the bone-implant interface can be anticipated. In the clinical practice, implementation of this prosthesis type could allow for early patient mobilization with better short- and long-term treatment outcomes and may be beneficial for patients with irreparable comminuted coronoid fractures, severe arthritic changes or non-unions

Infected non-unions of proximal femoral fractures are difficult to treat. If debridement and revision fixation is unsuccessful, staged revision arthroplasty may be required. Non-viable tissue must be resected, coupled with the introduction of an antibiotic-eluting temporary spacer prior to definitive reconstruction. Definitive tissue microbiological diagnosis and targeted antibiotic therapy are required. In cases of significant proximal femoral bone loss, spacing options are limited. We present a case of a bisphosphonate-induced subtrochanteric fracture that progressed to infected non-union. Despite multiple washouts and two revision fixations, the infection remained active with an unfavourable antibiogram. The patient required staged revision arthroplasty including a proximal femoral resection. To enable better function by maintaining leg length and offset, a custom-made antibiotic-eluting articulating temporary spacer, the Cement-a-TAN, was fabricated. Using a trochanteric entry cephalocondylar nail as a scaffold, bone cement was moulded in order to fashion an anatomical, patient-specific, proximal femoral spacer. Following resolution of the infection, the Cement-a-TAN was removed and a proximal femoral arthroplasty was successfully performed. Cement-a-TAN is an excellent temporary spacing technique in staged proximal femoral replacement for infected non-union of the proximal femur where there has been significant bone loss. It preserves mobility and maintains leg length, offset and periarticular soft-tissue tension

Summary. Randomised controlled study evaluating new bone formation in vivo in fracture non-unions by bone marrow derived stromal cells (BMSC). These cells do not show statistically significant new bone formation. Age of the patient during fracture, diabetes and doubling time had been observed to be correlated with fracture healing. Introduction. Regenerating new bone by cell therapy could provide therapeutic options in many conditions such as fracture non-unions and osteo-chondral defect regeneration in advance OA. In this randomised controlled study we evaluated the efficacy of new bone formation by bone marrow derived stromal cells (BMSC) in patients with non-union. Methods. An ethically approved and adequately powered single centre randomised control trial recruited 35 patients for treatment of non-unions with BMSC. Bone marrow was harvested and autologous BMSC were culture expanded in autologous serum at our local MHRA-licensed facility (Oscell, Oswestry, UK). Following selection by adherence and in vitro culture expansion using autologous serum, cells in serum and serum alone was randomised for insertion at one of the two fracture sides by StratOs® computer software. Patients and the operating surgeon were blinded to the side of cell insertion. Such method of randomisation created internal controls at the fracture sites- one side receiving the cell (‘test side’) and other, not (‘control’). Serial radiographs extending up to an average of twelve months were evaluated by four independent assessors blinded to side of cell insertion. Callus formation and bridging of fracture was compared for ‘test’ and ‘control’ side. Radiological and clinical outcome at final follow-up was also noted. Results. Thirty five patients were recruited (21 males, 14 females; mean age 51.2±13.2SD). The mean duration of non-union was 3±2SD years, with a mean 3.5 (range 1–12) surgical interventions prior to BMSC insertion. Five patients had diabetes. New callus formation and fracture bridging was slow, with no significant difference between the cell-insertion and control side although a substantial improvement in fracture bridging/formation of new callus was noted at 9–12 months. Fracture union was achieved in 21 patients at final follow-up with failure to progress to union in 14 patients. Age at accident, having diabetes and cell doubling time during culture predicted union (r2=0.63, p=0.017). There was no reported adverse effects from the trial. Conclusion. The study concluded that patient biology predicts the final outcome in cases with non-union of fracture. Slower doubling time during in vitro expansion can be significantly correlated with failure to unite in addition to diabetes and age of the patient. BMSC's are safe option for cell therapy in a setting of non-union although it failed to show statistically significant difference of new bone formation or fracture bridging for up to one year

The management of bone defects and impaired fracture healing remains one of the most challenging clinical problems. Several treatments exist to aid in the healing of large bone defects, including biologics such as recombinant human bone morphogenetic protein-2 (BMP-2), yet all have met with limited success. Regeneration of bone requires a coordinated network of molecular signals where the local mechanical environment plays a major role in the success of the healing process. The mechanical environment itself is determined by the stiffness of the implant used to stabilize the fracture and weight-bearing, and if fixation is either too flexible or too rigid the healing might fail. The hypothesis is that the healing of large-segmental bone defects and fractures can be accelerated by the imposition of an appropriate mechanical environment. An overview of the progress made in this research area on how the amount of rhBMP-2 could be reduced and its effectiveness increased by providing an optimized mechanical environment to achieve bone union will be presented. Additionally, the latest findings of improved fracture healing through the manipulation of fixation stability introducing a potential clinical strategy to improve the healing outcome of unstable fractures, particularly for non-unions through increased stabilization, will be discussed

PEMF is currently approved by the FDA for adjunctive treatment of lumbar/cervical spine fusion and for treatment of long-bone non-unions. Soft tissues are a potential new therapeutic application for PEMF due to pre-clinical studies showing a reduction of inflammatory markers following PEMF exposure. The aim was therefore to investigate the structural/functional effects of PEMFs on tendon-to-bone and tendon-to-tendon healing in a rotator-cuff (RC) and Achilles tendon (AT) repair model, respectively. RC study: Adult male rats (n=280), underwent bi-lateral supraspinatus tendon transections with immediate repair followed by cage activity until sacrifice (4, 8, and 16 weeks). Non-controls received PEMF for 1, 3, or 6 hours daily. AT study: Male rats underwent acute, complete transection and repair of the Achilles tendon (FULL, n=144) or full thickness, partial width injury (PART, n=160) followed by immobilization for 1 week. Sacrifice was at 1, 3, and 6 weeks. Outcome measures included passive joint mechanics, gait analysis, biomechanical assessments, histological analysis of the repair site and mCT (humerus) assessment (FULL only). RC study: Significant increases in modulus, stiffness, bone mineral content and improved collagen organization was observed for the PEMF groups. No differences in joint mechanics and ambulation were observed. AT study: A decrease in stiffness and limb-loading rate was observed for the PEMF groups for the FULL groups, whereas an increase in stiffness with no change in range-of-motion was seen for the PART groups. The combined studies show that PEMF can be effective for soft tissue repair but is dependent on the location of application

A substantial body of evidence supports the use of extracorporeal shock wave therapy (ESWT) for fracture non-unions in human medicine. However, the success rate (i.e., radiographic union at six months after ESWT) is only approximately 75%. Detailed knowledge regarding the underlying mechanisms that induce bio-calcification after ESWT is limited. The aim of the present study was to analyse the biological response within mineralized tissue of a new invertebrate model organism, the zebra mussel Dreissena polymorpha, after exposure with extracorporeal shock waves (ESWs). Mussels were exposed to ESWs with positive energy density of 0.4 mJ/mm. 2. or were sham exposed. Detection of newly calcified tissue was performed by concomitantly exposing the mussels to fluorescent markers. Two weeks later, the fluorescence signal intensity of the valves was measured. Mussels exposed to ESWs showed a statistically significantly higher mean fluorescence signal intensity within the shell zone than mussels that were sham exposed. Additional acoustic measurements revealed that the increased mean fluorescence signal intensity within the shell of those mussels that were exposed to ESWs was independent of the size and position of the focal point of the ESWs. These data demonstrate that induction of bio-calcification after ESWT may not be restricted to the region of direct energy transfer of ESWs into calcified tissue. The results of the present study are of relevance for better understanding of the molecular and cellular mechanisms that induce formation of new mineralized tissue after ESWT. Specifically, bio-calcification following ESWT may extend beyond the direct area of treatment

In the treatment of bone non-unions an alternative to bone autografts is the use of bone morphogenetic proteins (BMP-2, BMP-7) with powerful osteoinductive and osteogenic properties. In clinical settings, BMPs are applied using absorbable collagen sponges. Supraphysiological doses are needed and major side effects may occur as induce ectopic bone formation, chronic inflammation and excessive bone resorption. In order to increase the efficiency of the delivered for BMPs we designed cryostructured collagen scaffolds functionalized with hydroxyapatite, mimicking the structure of cortical bone (aligned porosity, anisotropic, ANI) or trabecular bone (random distributed porosity, isotropic, ISO). We hypothesize that anisotropic structure would enhance osteoconductive properties of the scaffolds increasing rhBMP-2 regenerative properties. In vitro, both scaffolds presented similar mechanical properties, rhBMP-2 retention and delivery capacity. For in vivo testing, a rat femoral critical size defect model was created. Four groups were assessed depending on the implant applied to the bone defect: ISO, unloaded isotropic sponge; ISO-BMP, isotropic sponge loaded with 5 μg of hrBMP-2; ANI, unloaded anisotropic sponge; and ANI-BMP, anisotropic sponge loaded with 5 μg of hrBMP-2. Regeneration was allowed for 10 weeks. X-ray, μCT, biomechanical testing and histology were used to evaluate repair. Independently of their structure, sponges loaded with rhBMP-2 demonstrate increased bone volume, and biomechanical properties than their controls (p<0.01 and p<0.05 respectively). Globally, ANI-BMP group demonstrated better bone regeneration outputs with increased defect bridging (p<0.05 when compared ANI-BMP vs ISO-BMP groups). In conclusion, anisotropic cryostructured collagen scaffolds improve the efficiency of rhBMP-2 in bone regeneration

Delayed facture repair and bony non-unions pose a clinical challenge. Understandably, novel methods to enhance bone healing have been studied by researchers worldwide. Electrical stimulation (ES) has shown to be effective in enhancing bone healing, however the best wave form and mechanism by which it stimulates osteoblasts remains unknown. Interestingly, it is considered that osteoblast activity depends on specific waveforms applied. Therefore, the aim of this study was to evaluate whether particular waveforms have a differential effect on osteoblast activity. An osteoblast cell line was electrically stimulated with either capacitive coupling (CC) or a novel degenerate wave (DW) using a unique in vitro ES system. Following application of both waveforms, the extent of cytotoxicity, proliferation, differentiation and mineralisation of the osteoblasts were assessed using various assays. Differentiation and mineralisation were further analysed using quantitative real-time PCR (qRT PCR) and immunocytochemistry (ICC). DW stimulation significantly enhanced the differentiation of the osteoblasts compared to CC stimulation, with increased protein and gene expression of alkaline phosphatase and type 1 collagen at 28 hours (p < 0.01). DW significantly enhanced the mineralisation of the osteoblasts compared to CC with greater Alizarin Red S staining and gene expression of osteocalcin, osteonectin, osteopontin and bone sialoprotein at 28 hours (p < 0.05). Moreover, immunocytochemical assays showed higher osteocalcin expression after DW stimulation compared to CC at 28 hours. In conclusion. we have shown that ES waveforms enhanced osteoblast activity to different extent but importantly demonstrate for the first time that DW stimulation has a greater effect on differentiation and mineralisation of osteoblasts than CC stimulation. DW stimulation has potential to provide a secure, controlled and effective application for bone healing. These findings have significant implications in the clinical management of fracture repair and bone. non-unions

INTRODUCTION. Staphylococci species account for ∼80 % of osteomyelitis cases. While the most severe infections are caused by Staphylococcus aureus (S. aureus), the clinical significance of coagulase negative Staphylococcus epidermidis (S. epidermidis) infections remain controversial. In general, S. epidermidis was known to be a protective commensal bacterium. However, recent studies have shown that intra-operative low-grade S. epidermidis contamination prevents bone healing. Thus, the purpose of this study is to compare the pathogenic features of S. aureus and S. epidermidis in an established murine model of implant-associated osteomyelitis. METHODS. All animal experiments were performed on IACUC approved protocols. USA300LAC (MRSA) and RP62A(S. epidermidis) were used as prototypic bacterial strains. After sterilization, stainless steel pins were implanted into the tibiae of BALB/c mice (n=5 each) with or without Staphylococci. Mice were euthanized on day 14, and the implants were removed for scanning electron microscopy (SEM). Tibiae were fixed for mCT prior to decalcification for histology. RESULTS. The histology of S. aureus infected tibiae demonstrated massive osteolysis and abscesses formation. In contrast, the histology from S. epidermidis infected tibiae was indistinguishable from uninfected controls. Gross mCT analyses revealed massive bone defects around the infected implant with reactive bone formation only in the S. aureus group. The osteolysis findings were confirmed by quantitative analysis, as the medial hole area of S. aureus infected tibiae (1.67 ± 0.37 mm2) was larger than uninfected (0.15 ± 0.10 mm2) (p < 0.001) and S. epidermidis (0.19 ± 0.14 mm2) (p < 0.001) groups. Consistently, the %biofilm area on the implants of the S. aureus group (39.0 ± 13.7 %) was significantly larger than uninfected (6.3 ± 2.3 %) (p < 0.001) and S. epidermidis (12.9 ± 7.4 %) (p < 0.001). Although the amount of biofilm of S. epidermidis was much smaller than S. aureus, the presence of bacteria on the implant were confirmed by SEM. In addition, the empty lacunae, which is a feature of mature biofilm and evidence of bacterial emigration, were also present on both S. epidermidis and S. aureus infected implants. DISCUSSION. In this study, we confirmed the aggressive pathologic features S. aureus on host bone, soft tissues and biofilm formation. In contrast, we show that S. epidermidis is incapable of inducing osteolysis, reactive bone formation or soft tissue abscesses, even though it colonizes the implant in small biofilms. Collectively, the results support a potential role for S. epidermidis in implant loosening and fracture non-unions, as the bacteria can form small biofilms that could interfere with osseous integration and bone healing. However, future studies are warranted to assess the effects of S. epidermidis biofilm on implant loosening

Delayed bone healing and nonunion are complications of long bone fractures, with prolonged pain and disability. Regenerative therapies employing mesenchymal stromal cells (MSC) and/or bone substitutes are increasingly applied to enhance bone consolidation. The REBORNE project entailed a multi-center orthopaedic clinical trial focused on the evaluation of efficacy of expanded autologous bone marrow (BM) derived MSC combined with a CaP-biomaterial, to enhance bone healing in patients with nonunion of diaphyseal fractures. To complement the clinical and radiological examination of patients, bone turnover markers (BTM) were assayed as potential predictors of bone healing or non-union. Peripheral blood was collected from patients at fixed time-endpoints, that is at 6,12 and 24 weeks post-surgery for implantation of expanded autologus MSC and bone-like particles. Bone-specific alkaline phosphatase (BAP), C-terminal-propeptide type I-procollagen (PICP), osteocalcin (OC), β-Cross-Laps Collagen (CTX), soluble receptor activator of NFkB (RANKL), osteoprotegerin (OPG) were measured by ELISA assays in blood samples of 22 patients at BM collection and at follow-up visits. A significant relationship with age was found only at 6 months, with an inverse correlation for CTX, RANKL and OC, and positive for OPG. BTM levels were not related to gender. As an effect of local regenerative process, some BTM showed significant changes in comparison to the baseline value. In particular, the time course of BAP, PICP and RANKL was different in patients with a successful healing in comparison to patients with a negative outcome. The BTM profile apparently indicated a remarkable bone formation activity 12 weeks after surgery. However, the paucity of failed patients in our case series did not allow to prove statistically the role of BTM as predictors of the final outcome. Blood markers related to bone cell function are useful to measure the efficacy of a expanded MSC-regenerative approach applied to long bone non-unions. Changes of the markers may provide a support to radiological assessment of bone healing

Displaced proximal Humeral fractures at Inverclyde Royal Hospital prior to 2008 were previously treated with the antegrade Acumed Polaris Proximal Humeral, predominantly in 2 part fractures. The Philos plate was introduced in 2008, initially being used to treat select non unions, and then expanded to acute fractures. The aim of this study was to assess time to union and complications in the lower volume District General setting comparing to published outcomes. From February 2008 – January 2011, 20 patients were identified. Age range 49–75 (mean 61.2) years, 8 male; 12 female. Left 9, Right 11 Neers 2 part 35%; 3 35%; 4 30%. 16 (80%) were performed in acute fractures with 4 for non-unions, 3 of which were previous polaris nail fixations. 2 patients were lost to follow up after 6/52 but were progressing well. Union was confirmed radiologically and clinically in all but 2 remaining patients (10%), one of whom suffered a significant complication of plate fracture, the second treated with revision for painful non union. 2 other significant complications were observed: transient axillary nerve palsy and deep infection. Both of these patients recovered with delayed union observed in the infection case (52 weeks). Time to union range was 8–52 weeks (mean 17.1). The literature shows a high failure rate of up to 45% with intramedullary nail fixation and limited predominantly to 2 part fractures with risk of damage to the rotator cuff. This study shows a satisfactory union rate using the Philos of 90% with only 3 (15%) requiring further surgery for non-union, plate fracture and infection. 3 and 4 part fractures composed 65% of case load. Early results indicate satisfactory outcomes compared to current published literature