Segmental bone transport (SBT) using an external fixator is currently a standard treatment for large-diameter bone defects at the donor site with low morbidity. However, long-term application of the device is needed for bone healing. In addition, patients who received SBT treatment sometimes fail to show bone repair and union at the docking site, and require secondary surgery. The objective of this study was to investigate whether a single injection of recombinant human bone morphogenetic protein 2 (rhBMP-2)-loaded artificial collagen-like peptide gel (rhBMP-2/ACG) accelerates consolidation and bone union at the docking site in a mouse SBT model. Six-month-old C57BL/6J mice were reconstructed by SBT with external fixator that has transport unit, and a 2.0-mm bone defect was created in the right femur. Mice were divided randomly into four treatment groups with eight mice in each group, Group CONT (immobile control), Group 0.2mm/d, Group 1.0mm/d, and Group BMP-2. Mice in Group 0.2mm/d and 1.0mm/d, bone segment was moved 0.2 mm per day for 10 days and 1.0 mm per day for 2 days, respectively. Mice in Group BMP-2 received an injection of 2.0 μg of rhBMP-2 dissolved in ACG into the bone defect site immediately after the defect-creating surgery and the bone segment was moved 1.0 mm/day for 2 days. All animals were sacrificed at eight weeks after surgery. Consolidation at bone defect site and bone union at docking site were evaluated radiologically and histologically. At the bone defect site, seven of eight mice in Group 0.2mm/d and two of eight mice in Group 1.0mm/d showed bone union. In contrast, all mice in Group CONT showed non-union at the bone defect site. At the docking site, four of eight mice in Group 0.2 mm/d and three of eight mice in Group 1.0 mm/d showed non-union. Meanwhile, all mice in Group BMP-2 showed bone union at the bone defect and docking sites. Bone volume and bone mineral content were significantly higher in Group 0.2mm/d and Group BMP-2 than in Group CONT. HE staining of tissue from Group 0.2mm/d and Group BMP-2 showed large amounts of longitudinal trabecular bone and regenerative new bone at eight weeks after surgery at the bone defect site. Meanwhile, in Group CONT and Group 1.0mm/d, maturation of regenerative bone at the bone defect site was poor. Differences between groups were analyzed using one-way ANOVA and a subsequent Bonferroni's post-hoc comparisons test. P < 0.05 was considered significant. rhBMP-2/ACG combined with SBT may be effective for enhancing bone healing in large bone defects without the need for secondary procedures

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

Introduction. Distal femur fractures around a total knee arthroplasty (TKA) are a growing problem for orthopaedic surgeons. The purpose of this study was to identify risks of reoperation for nonunion following open reduction and internal fixation of TKA periprosthetic distal femur fractures (PDFF). Method. Patients with PDFF (AO 33A-C[VB1, C1, D1], Su types 1-3) managed operatively with open reduction and internal fixation (ORIF) were retrospectively reviewed. Exclusion criteria were acute management with a distal femur replacement, less than 6 months of follow-up, and lack of injury or follow-up radiographs. The primary outcome measure was reoperation to achieve bony union. Comparisons were made between cases that did and did not require a reoperation to achieve union. Univariate analysis was used to identify factors to be analyzed in multivariate analysis to determine independent risk factors for the primary outcome. Result. A total of 77 patients met inclusion criteria. Union rate was 69/77 (89.6%). There were no differences between the groups for age, sex, BMI, comorbidities, Su classification, open injury, or mechanism of injury. Multivariate analysis identified risks for nonunion including post-operative malalignment (OR 1.41; CI 1.20-1.64; p<0.001), notching pre-operatively (OR 1.22; CI 1.04-1.42; p=0.012), presence of screws through fracture line (OR 1.28; CI 1.17-1.39; p<0.001), plate length <12 holes (OR 1.16; CI 1.02-1.33; p=0.024) and screw density greater than 0.4 (OR 2.18; CI 1.25-3.78; p=0.006). Conclusion. The reoperation rate to promote union was 10.4%. The study identified post-operative malalignment, notching pre-operatively, presence of screws through fracture line, plate length <12 holes, and proximal screw density greater than 40% as independent risk factors for nonunion

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

Introduction and Objective. Despite the low incidence of pilon fractures among lower limb injuries, their high-impact nature presents difficulties in surgical management and recovery. Current literature includes a wide range of different management strategies, however there is no universal treatment algorithm. We aim to determine clinical outcomes in patients with open and closed pilon fractures, managed using a treatment algorithm that was applied consistently over the span of this study. Materials and Methods. This retrospective study was conducted at a single institution, including 141 pilon fractures in 135 patients, from August 2014 to January 2021. AO/OTA classification was used to classify fractures. Among closed fractures, 12 had type 43A, 18 had type 43B, 61 had type 43C. Among open fractures, 11 had type 43A, 12 had type 43B, 27 had type 43C. Open fractures were further classified with Gustilo-Anderson (GA); type 1: n=8, type 2: n=10, type 3A: n=12, type 3B: n=20. Our treatment algorithm consisted of fine wire fixator (FWF) for severely comminuted closed fractures (AO/OTA type 43C3), or open fractures with severe soft tissue injury (GA type 3). Otherwise, open reduction internal fixation (ORIF) was performed. When required, minimally invasive osteosynthesis (MIO) was performed in combination with FWF to improve joint congruency. All open fractures, and closed fractures with severe soft tissue injury (skin contusion, fracture blister, severe oedema) were initially treated with temporary ankle-spanning external fixation. For all open fracture patients, surgical debridement, soft tissue cover with a free or pedicled flap were performed. For GA types 1 and 2, this was done with ORIF in the same operating session. Those with severe soft tissue injury (GA type 3) were treated with FWF four to six weeks after soft tissue management was completed. Primary outcome was AOFAS Ankle-Hindfoot score at 3, 6 and 12-months post-treatment. Secondary outcomes include time to partial weight-bear (PWB) and full weight-bear (FWB), bone union time. All complications were recorded. Results. Mean AOFAS score 3, 6, and 12 months post-treatment for open and closed fracture patients were 44.12 and 53.99 (p=0.007), 62.38 and 67.68 (p=0.203), 78.44 and 84.06 (p=0.256), respectively. 119 of the 141 fractures healed without further intervention (84.4%). Average time to bone union was 51.46 and 36.48 weeks for open and closed fractures, respectively (p=0.019). Union took longer in closed fracture patients treated with FWF than ORIF (p=0.025). On average, open and closed fracture patients took 12.29 and 10.76 weeks to PWB (p=0.361); 24.04 and 20.31 weeks to FWB (p=0.235), respectively. Common complications for open fractures were non-union (24%), post-traumatic arthritis (16%); for closed fractures they were post-traumatic arthritis (25%), superficial infection (22%). Open fracture was a risk factor for non-union (p=0.042; OR=2.558, 95% CI 1.016–6.441), bone defect (p=0.001; OR=5.973, 95% CI 1.986–17.967), and superficial infection (p<0.001; OR=4.167, 95% CI 1.978–8.781). Conclusions. The use of a two-staged approach involving temporary external fixation followed by definitive fixation, provides a stable milieu for soft tissue recovery. FWF combined with MIO, where required for severely comminuted closed fractures, and FWF for open fractures with severe soft tissue injury, are safe methods achieving low complication rates and good functional recovery

Abstract. Objectives. Current literature on pilon fracture includes a range of different management strategies, however there is no universal treatment algorithm. We aim to determine clinical outcomes in patients with open and closed pilon fractures, managed using a treatment algorithm applied consistently over the span of this study. Methods. 135 patients over a 6-year period were included. Primary outcome was AOFAS score at 3, 6, 12-months post-injury. Secondary outcomes include time to partial weight-bear (PWB), full weight-bear (FWB), bone union time, follow-up time. AO/OTA classification was used (43A: n=23, 43B: n=30, 43C: n=82). Treatment algorithm consisted of fine wire fixator (FWF) for severely comminuted closed fractures (AO/OTA type 43C3), or open fractures with severe soft tissue injury (GA type 3). Otherwise, open reduction internal fixation (ORIF) was performed. When required, minimally invasive osteosynthesis was performed in combination with FWF to improve joint congruency. Results. Mean AOFAS score 3, 6, and 12 months post-treatment for open and closed fracture patients were 44.12 and 53.99 (p=0.007), 62.38 and 67.68 (p=0.203), 78.44 and 84.06 (p=0.256), respectively. 119 of 141 fractures healed without further intervention (84.4%). Average time to union was 51.46 and 36.48 weeks for open and closed fractures, respectively (p=0.019). On average, open, and closed fracture patients took 12.29 and 10.76 weeks to PWB (p=0.361); 24.04 and 20.31 weeks to FWB (p=0.235), respectively. Common complications for open fractures were non-union (24%), post-traumatic arthritis (16%); for closed fractures they were post-traumatic arthritis (25%), superficial infection (22%). Open fracture was a risk factor for non-union (p=0.042;OR=2.558,95% CI 1.016–6.441), bone defect (p=0.001;OR=5.973,95% CI 1.986–17.967), and superficial infection (p<0.001;OR=4.167,95% CI 1.978–8.781). Conclusions. FWF with minimally invasive osteosynthesis, where required for severely comminuted closed fractures, and FWF for open fractures with severe soft tissue injury, are safe methods achieving low complication rates and good functional recovery

Previous clinical studies have shown the efficacy of a foreign body-induced membrane combined with bone autograft for the reconstruction of traumatologic or pathologic large bone defects or, bone non union. This membrane, rich in mesenchymal stromal cells (MSC), avoids bone autograft resorption and promotes consolidation by revascularisation of the bone and secretion of growth factors. Reconstruction requires two different surgical stages: firstly, insertion of a cement spacer in the defect, and secondly, removal of the spacer, preservation of the foreign body-induced membrane and filling of the cavity by bone autograft. The optimal time to perform the second surgical stage remains unclear. So, we aimed to correlate bone healing and, phenotype and function of cells isolated from the induced membrane, in patients whose second surgery was performed on average after 6 months (i.e. beyond the recommended time of one month). Cell phenotype was determined by flow cytometry and cell function by: alkaline Phosphatase enzyme activity, secretion of calcium and von Kossa staining. Second, using histological and immunohistochemistry studies, we aimed to determine the nature and function of induced membrane over time. Seven patients were included with their consent. Results showed Treated patients achieved in all cases bone union (except for one patient) and in in vitro and histology and immunohistochemistry gave some indications which need to be completed in the future. First, patient age seemed to be an indicator of bone union speed and recurrent infection, appeared to influence in vitro MSC osteogenic potential and induced membrane structure. Second, we reported, in bone repair situation, the commitment over time in osteogenic lineage of a surprising multipotent tissue (induced membrane) able of vascularisation/ osteogenesis/ chondrogenesis at a precocious time. Finally, best time to perform the second stage (one month) could be easily exceeded since bone union occurred even at very late times

The large bone defects with high risk of delayed bone union and pseudoarthrosis remain significant clinical challenge. Aim of the present study was the investigation of the critical size fracture healing process in transgenic mice using a novel beta-TCP scaffold. The luciferase transgenic mice strains (BALB/C-Tg(NF-kappaB-RE-luc)-Xen) and FVB/N-Tg(Vegfr2-luc)-Xen were used. Critical size fracture on femur was performed and stabilized using external fixation (RISystem). The fracture was bridged with a synthetic scaffold with and without Strontium. In consequence, the expression levels of NF-kappaB and VEGFR2 could be monitored in a longitudinal fashion using the Xenogen imaging system for two months. Animals were euthanized, serial section of femur were prepared, and the fracture sites were histologically examined. Sr reduced inflammation in the early phase of healing (15th days), but it was increased in the late healing stage. The level of VEGFR2 activity increases in the Sr doped beta-TCP group at the 15th day, the luciferase activity starts to decrease in this group and show significantly less activity compared to other groups in the second half. In the group without scaffold a connective tissue formation were observed. In both, beta-TCP and beta-TCP+Sr, the connection of newly formed tissue within integrated canals in scaffold was visible. Tissue formation in beta-TCP+Sr group was significantly higher than in the beta-TCP group, whereas the percentage of osseous tissue in relation to the newly formed tissue was in beta-TCP scaffold much more than in beta-TCP+ Sr groups. This study presents the first data regarding VEGFR2 and NF-kappB and angiogenesis activity profiles during fracture healing. The collected longitudinal data reduces the number of experimental animals in the study. Addition of strontium in scaffolds influenced the inflammation in different stage of the healing. This effect might influence the healing process and may prove to be advantageous for osteoporosis fracture healing

Clavicular hook plates have been used over the last decade in the treatment of lateral clavicular fractures with good rates of union reported throughout the literature. Fewer studies have reported the functional outcome of these patients and some have reported potential soft tissue damage post plate removal. We aimed to review the functional outcomes alongside union rates in patients treated with hook plates for lateral clavicular fractures. In this retrospective case series, 21 patients with traumatic lateral third clavicular fractures were included. 15 had Neer type II fractures, 4 Neer type III fractures, 1 patient had a Neer type I fracture and 1 radiograph was not able to be classified. All patients were treated with clavicular hook plates at the same district general hospital by five experienced surgeons between March 2010 and February 2015 adhering to the same surgical protocol. All patients had standard physiotherapy and post operative follow up. Plates were removed when radiological union was achieved in all but one patient who had the plate removed before union was achieved due to prolonged non-union. Patients were followed up post plate removal and evaluated clinically using the Oxford Shoulder Score. Their post plate radiographs were assessed by an independent radiologist and bony union documented. 21 patients were included. Mean age was 40 (range 14–63) with a male:female ratio of 17:4. Mean follow up was 5 months post injury (1–26 months). The hook plate remained in situ for a mean time of 4.3 months (2–16 months). One patient developed a post-operative wound infection treated with antibiotics, 2 patients developed adhesive capsulitis, one patient had not achieved bony union prior to hook plate removal at 16 months, however did achieve union 2 months post plate removal, two patients required revision plating. All patients achieved bony union eventually with good alignment and no displacement of the acromioclavicular joint seen on the most recent post operative radiographs. Post plate removal Oxford Shoulder Scores indicated good shoulder function with a mean score of 41.5 (maximum score possible 48 and the range of scores for our cohort was 30–47). Our data would support the use of hook plates in the treatment of lateral clavicular fractures. All patients achieved union eventually with good alignment and this was reflected in the good functional outcome scores. This study is limited in its small cohort and short-term follow up. More research is required to examine the long term consequences of hook plate surgery in a larger patient population

The use of retrograde femoral intramedullary nails in children for deformity correction is controversial. It is unknown if the injury to the central part of the growth plate results in premature bony union, leading to limb deformities or discrepancies. The aim of this study was to assess physeal healing and bone growth after insertion of a retrograde femoral nail thorough the centre of the physis in a skeletally immature experimental porcine model. Eleven immature pigs were included in the study. One leg was randomised for operation with a retrograde femoral nail (diameter 10.7 mm), whilst the non-operated contralateral remained as control. All nails were inserted centrally in coronal and sagittal plane under fluoroscopic guidance, and the nails spanned the physis. The nails were removed at 8 weeks. Both femora in all animals underwent MRI at baseline (pre-operatively), 8 weeks (after nail removal) and 16 weeks (before euthanasia). Femoral bone length was measured at 5 sites (anterior, posterior, central, lateral and medial) using 3d T1-weighted MRI. Growth was calculated after 8 weeks (growth with nail) and 16 weeks (growth without nail). Physeal cross-sectional area and percentage violated by the nail was determined on MRI. Operated side was compared to non-operated. Corresponding 95% confidence intervals were calculated. No differences in axial growth were observed between operated and non-operated sides. Mean growth difference was 0,61 mm [−0,78;2,01] whilst the nail was inserted into the bone and 0,72 mm [−1,04;1,65] after nail removal. No signs of angular bone deformities were found when comparing operated side to non-operated side. No premature bony healing at the physis occurred. Histology confirmed fibrous healing. Mean physeal violation was 5.72% [5.51; 5.93] by the femoral nail. The insertion of a retrograde femoral nail through the centre of an open physis might be a safe procedure with no subsequent growth arrest. However, experiments assessing the long term physeal healing and growth are needed

Bone tissue engineering constructs (BTEC) combining natural resorbable osteoconductive scaffolds and mesenchymal stem cells (MSCs) have given promising results to repair critical size bone defect. Yet, results remain inconsistent. Adjonction of an osteoinductive factor to these BTEC, such as rh-BMP-2, to improve bone healing, seems to be a relevant strategy. However, currently supraphysiological dose of this protein are used and can lead to adverse effects such as inflammation, ectopic bone and/or bone cyst formation. Interestingly, in a preliminary study conducted in ectopic site in a murine model, a synergistic effect on bone formation was observed only when a low dose of rh-BMP-2 was associated with MSCs-seeded coral scaffolds but not with a high dose. The objective of the study was then to evaluate a BTEC combining coral scaffold, MSCs and a low dose of rh-BMP-2 in a large animal model of clinical relevance. Sixteen sheep were used for this study. MSCs were isolated from an aspirate of bone marrow harvested from the iliac crest of each sheep receiving BTEC with MSCs, cultivated and seeded on Acroporacoral scaffolds one week before implantation. Rh-BMP-2, used at two different doses (low dose: 68μg/defect and high dose: 680μg/defect), was diluted and absorbed on Acroporacoral scaffold one day before implantation. Metatarsal segmental bone defects (25 mm) were made in the left metatarsal bone of the sheep, stabilized by plate fixation, and filled with Acroporacoral scaffolds loaded with either (i) MSCs and a low dose of rh-BMP-2 (Group 1;n=6), (ii) a low dose of rh-BMP-2 (Group 2;n=5), (iii) a high dose of rh-BMP-2 (Group 3;n=5). Standard radiographs were taken after each surgery and each month until sheep sacrifice, 4 months postoperatively. Bone healing and scaffold resorption were assessed by micro-computed-tomography (μCT) and histomorphometry. Results were compared to a historical control group in which coral scaffolds were loaded with MSCs. Bone volumes (BV) evaluated by μCT and bone surfaces (BS) evaluated by histomorphometry did not differ between groups (BV: 1914±870, 1737±841, 1894±1028 and 1835±1342 mm. 3. ; BS: 25,41±14,25, 19,85±8,31, 25,54±16,98 and 26,08±22,52 %; groups 1, 2, 3 and control respectively); however, an higher bone union was observed in group 1 compared to the others (3, 1, 2 and 2 sheep with bone union in groups 1, 2, 3 and control respectively). No histological abnormalities were observed in any group. Coral resorption was almost complete in all specimens. No significant difference in coral volumes and coral surfaces was observed between groups. A trend towards a higher variability in coral resorption was noted in group 1 compared to the others. There seems to be a benefit to associate low dose of rh-BMP-2 with MSCs-seeded coral scaffolds as this strategy allowed an increase of bone unions in our model. Yet, results remain inconsistent. Although, defective coupling between scaffold resorption and bone formation impaired bone healing in some animals, adjunction of rh-BMP-2 (even at low dose) to CSMs loaded construct is a promising strategy for bone tissue engineering

Introduction. The BOAST (British Orthopaedic Association Standards for Trauma) guidelines do advise that open pilon fractures amongst other open lower limb fractures need to be treated at a specialist centre with Orthoplastic care. The purpose of this study was to determine clinical outcomes in patients with open pilon fractures treated as per BOAST guidelines including relatively aggressive bone debridement. Methods. A retrospective analysis of a single surgeon series of open pilon fractures treated between 2014 and 2019 was conducted. Injuries were graded according to the Gustillo-Anderson classification and all patients were included for the assessment of the rate of infection and fracture healing. Functional outcome assessment was performed in all patients according to the American Orthopedic Foot and Ankle Score (AOFAS) at 6 months after definitive surgery. Initial wound with bone debridement and application of a spanning external fixator was performed within an average of 13.5 (Range: 3–24) hours. Fixation with FWF (Fine Wire Frame) was performed when the wound was healed, with the mean time from primary surgery to application of FWF being 24.5 (Range: 7–60) days. Results. There was a total of 20 patients including 16 males and 4 females. The mean age was 50.45 (Range: 16–88) years. Follow-up was for an average of 23.2 (Range: 5–51) months. There were 3 patients with Gustilo Type I injuries, 6 with Type II, 4 Type with type IIIa and 7 with Type IIIb injuries. Average time to bone union was 9.3 (Range: 2–18) months. The mean AOFAS score was 66 (Range: 15–97) points. TSF was used on 18 patients, while 2 patients had an Ilizarov frame. A corticotomy was performed on 4 patients with critical bone defect post debridement, while 2 patients had Stimulan beads with antibiotics. There was 1 case (5%) of deep infection and 9 cases (45%) of superficial infection. There were also 2 cases (10%) of non-union which required bone grafting from their femur using a RIA (Reamer Irrigation Aspirator). Other complications included 1 case of acute compartment syndrome, 1 case of pulmonary embolism, 1 case of necrotic skin and 1 case of amputation. Conclusion. Results of our study suggests that the use of staged wound debridement including relatively aggressive bone debridement in conjunction with antibiotics, external fixators and patient tailored conversion from spanning external fixator to fine wire frame achieves low rates of wound infection and complications for patients with open pilon fractures

Objectives. To compare the therapeutic potential of tissue-engineered constructs (TECs) combining mesenchymal stem cells (MSCs) and coral granules from either Acropora or Porites to repair large bone defects. Materials and Methods. Bone marrow-derived, autologous MSCs were seeded on Acropora or Porites coral granules in a perfusion bioreactor. Acropora-TECs (n = 7), Porites-TECs (n = 6) and bone autografts (n = 2) were then implanted into 25 mm long metatarsal diaphyseal defects in sheep. Bimonthly radiographic follow-up was completed until killing four months post-operatively. Explants were subsequently processed for microCT and histology to assess bone formation and coral bioresorption. Statistical analyses comprised Mann-Whitney, t-test and Kruskal–Wallis tests. Data were expressed as mean and standard deviation. Results. A two-fold increaseof newly formed bone volume was observed for Acropora-TECs when compared with Porites-TECs (14 . sd. 1089 mm. 3. versus 782 . sd. 507 mm. 3. ; p = 0.09). Bone union was consistent with autograft (1960 . sd. 518 mm. 3. ). The kinetics of bioresorption and bioresorption rates at four months were different for Acropora-TECs and Porites-TECs (81% . sd. 5% versus 94% . sd. 6%; p = 0.04). In comparing the defects that healed with those that did not, we observed that, when major bioresorption of coral at two months occurs and a scaffold material bioresorption rate superior to 90% at four months is achieved, bone nonunion consistently occurred using coral-based TECs. Discussion. Bone regeneration in critical-size defects could be obtained with full bioresorption of the scaffold using coral-based TECs in a large animal model. The superior performance of Acropora-TECs brings us closer to a clinical application, probably because of more suitable bioresorption kinetics. However, nonunion still occurred in nearly half of the bone defects. Cite this article: A. Decambron, M. Manassero, M. Bensidhoum, B. Lecuelle, D. Logeart-Avramoglou, H. Petite, V. Viateau. A comparative study of tissue-engineered constructs from Acropora and Porites coral in a large animal bone defect model. Bone Joint Res 2017;6:208–215. DOI: 10.1302/2046-3758.64.BJR-2016-0236.R1

Introduction. 20 cases of bone defect have been treated by the induced membrane technique avoiding allograft, microsurgery and amputation. Material and Methods. 9 cases of long bone defect (humerus and 2 bones arm) and 11 cases of bone defct at the hand have been included in this multicentric prospective study (3 centers). 11 cases were traumatic, 7 cases were septic non union and 2 cases were tumor. At hand level's bone reached at least one phalanx, and for long bone the mean defect was 5cm (3–11). All cases were treated by the induced membrane technique which consists in stable fixation, flap if necessary and in filling the void created by the bone defect by a cement spacer (PMMA). This technique needs a second stage procedure at the 2. nd. month where the cement is removed and the void is filled by cancellous bone. The key point of this induced membrane technique is to respect the foreign body membane which appeared around the cement spacer and which create a biologic chamber after the second time. Bone union was evaluated prospectively in each case by an surgeon not involved in the treatment by Xray and CT scan. Failure was defined as a non union at 1 year, or an uncontrolled sepsis at 1 month. Results. 3 cases failed to achieve bone union, 2 at hand level and 1 for long bone. No septic complications occured and all septic cases werre stopped. In 14 cases bone union was achieved with a delay of 5 months (1, 5–12). 2 biopsies allowed to proove us that osteoid tissue was created by the technic. At hand level all fingers have included. At shoulder and elbow level, function reached 75% of motion than controlateral side. Discussion. Masquelet first reported 35 cases of large bone defect of tibia non union treated by the induced membrane technic which allow to fill bone defect with cancellous bone alone. The cement spacer allows to induce a foreign body membrane which constitute a biological chamber. Works on animal model reported by Pellissier and Viatteau showed the properties of the membrane: secretion of growths factors (VEGF, TGFbéta1, BMP2) and osteoinductive activitie of the cells. The induced membrane seem to play the role of a neo periosteum. Using this technic is possible in emergency or in septic condition where bone defect can not been solved by shortening. This technic avoids to use microsurgical technic and the limit is the quantity of avalaible cancellous bone

The TL Hex (Orthofix) is a relatively new hexapod frame system that we have been using at our institution since August 2013 to treat acute fractures and correct tibial and femoral deformity. We report our initial experience of 48 completed treatments with this novel system in 46 patients and discuss illustrative cases. For acute fracture, 30 patients (24 male, 7 female) required framing with a mean age of 43 years (range 19–80). One patient underwent bilateral framing. The tibia was involved in all cases. In two cases, the femur also required framing. Open fractures occurred in 13 cases (43.3%). For elective limb reconstruction, 16 patients (14 male, two female) required framing with a mean age of 35 years (range 16–67). One patient underwent bilateral framing. The tibia was involved in all but one case, which affected the femur. Surgical indications included congenital deformity in four cases, malunion in eight cases, non-union in three cases and chronic infection in two cases. For acute fractures, the mean frame time was 164 days (range 63–560) and all but one fracture achieved union. Complications included pin, wire or strut failure requiring adjustment (three patients) and pin site infection (six patients). Three patients are being considered for residual deformity correction or treatment of non-union. In the elective limb reconstruction group, mean frame time was 220 days (range 140–462). All treatments successfully achieved deformity correction and bone union. Complications included two pin site infections. There was no evidence of recurrence of infection in the two osteomyelitis cases. In conclusion, the TL Hex frame system appears to be a safe and reliable tool for limb reconstruction. We have observed acceptable frame times, low complication rates and almost 100% bony union

Objectives. The objective of this study was to investigate the therapeutic effect of peripheral blood mononuclear cells (PBMNCs) treated with quality and quantity control culture (QQ-culture) to expand and fortify angiogenic cells on the acceleration of fracture healing. Methods. Human PBMNCs were cultured for seven days with the QQ-culture method using a serum-free medium containing five specific cytokines and growth factors. The QQ-cultured PBMNCs (QQMNCs) obtained were counted and characterised by flow cytometry and real-time polymerase chain reaction (RT-PCR). Angiogenic and osteo-inductive potentials were evaluated using tube formation assays and co-culture with mesenchymal stem cells with osteo-inductive medium in vitro. In order to evaluate the therapeutic potential of QQMNCs, cells were transplanted into an immunodeficient rat femur nonunion model. The rats were randomised into three groups: control; PBMNCs; and QQMNCs. The fracture healing was evaluated radiographically and histologically. Results. The total number of PBMNCs was decreased after QQ-culture, however, the number of CD34+ and CD206+ cells were found to have increased as assessed by flow cytometry analysis. In addition, gene expression of angiogenic factors was upregulated in QQMNCs. In the animal model, the rate of bone union was higher in the QQMNC group than in the other groups. Radiographic scores and bone volume were significantly associated with the enhancement of angiogenesis in the QQMNC group. Conclusion. We have demonstrated that QQMNCs have superior potential to accelerate fracture healing compared with PBMNCs. The QQMNCs could be a promising option for fracture nonunion. Cite this article: K. Mifuji, M. Ishikawa, N. Kamei, R. Tanaka, K. Arita, H. Mizuno, T. Asahara, N. Adachi, M. Ochi. Angiogenic conditioning of peripheral blood mononuclear cells promotes fracture healing. Bone Joint Res 2017;6: 489–498. DOI: 10.1302/2046-3758.68.BJR-2016-0338.R1

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

Segmental bone transport (SBT) with an external fixator has become a standard method for treatment of large bone defect. However, a long time-application of devices can be very troublesome and complications such as nonunion is sometimes seen at docking site. Although there have been several studies on SBT with large animal models, they were unsuitable for conducting drug application to improve SBT. The purpose of this study was to establish a bone transport model in mice. Six-month-old C57BL/6J mice were divided randomly into bone transport group (group BT) and an immobile control group (group EF). In each group, a 2-mm bone defect was created in the right femur. Group BT was reconstructed by SBT with external fixator (MouseExFix segment transport, RISystem, Switzerland) and group EF was fixed simply with unilateral external fixator (MouseExFix simple). In group BT, a bone segment was transported by 0.2 mm per day. Radiological and histological studies were conducted at 3 and 8 weeks after the surgery. In group BT, radiological data showed regenerative new bone consolidation at 8 weeks after the surgery, whereas high rate of nonunion was observed at the docking site. Histological data showed intramembranous and endochondral ossification. Group EF showed no bone union. In this study, experimental group showed good regenerative new bone formation and was similar ossification pattern to previous large animal models. Thus, the utilization of this bone defect mice model allows to design future studies with standardized mechanical conditions for analyzing mechanisms of bone regeneration induced by SBT

Medial open-wedge high tibial osteotomy has been gaining popularity in recent years, but adequate supporting material is required in the osteotomy gap for early weight-bearing and rapid union. The purpose of this study was to investigate whether the implantation of a polycaprolactone-tricalcium phosphate composite scaffold wedge would enhance healing of the osteotomy in a micro pig model. We carried out open-wedge high tibial osteotomies in 12 micro pigs aged from 12 to 16 months. A scaffold wedge was inserted into six of the osteotomies while the other six were left open. Bone healing was evaluated after three and six months using plain radiographs, CT scans, measurement of the bone mineral density and histological examination. Complete bone union was obtained at six months in both groups. There was no collapse at the osteotomy site, loss of correction or failure of fixation in either group. Staining with haematoxylin and eosin demonstrated that there was infiltration of new bone tissue into the macropores and along the periphery of the implanted scaffold in the scaffold group. The CT scans and measurement of the bone mineral density showed that at six months specimens in the scaffold group had a higher bone mineral density than in the control group, although the implantation of the polycaprolactone-tricalcium phosphate composite scaffold wedge did not enhance healing of the osteotomy

The aim is to report a rare technique for correction of intramedullary nail acute angular deformity. Intramedullary tibial nail fixation of diaphyseal tibial fractures is the gold standard treatment allowing early mobilisation whilst preserving the soft tissues around the fracture site. Most commonly, intramedullary nails fail by metal fatigue secondary to non union, without significant deformity of the metalwork. Plastic deformity of the nail can result following new acute trauma, particularly before bone union has occurred. This is a clinical challenge as a reamed intramedullary nail is designed to achieve three point fixation with close anatomical fit, such that removal of a bent nail is technically difficult and also risks further damage to bone and soft tissues. We report a case of a 20 year old patient treated with intramedullary nail fixation of a diaphyseal right tibial fracture who was subsequently assaulted 4 weeks post operatively. This produced an unacceptable deformation of the nail into 25 degrees valgus and procurvatum. To remove the nail, the authors used a previously reported but rare technique of partial (up to 50%) nail division on the convex surface of the apex using Midas Rex High Speed Drill to weaken the nail then manipulation to correct deformity with minimal stress. The technique produced minimal metal debris and allowed simple exchange nail replacement without further complication. The authors believe this is the first reported use of the technique from the United Kingdom