The effect of head injury on systemic physiology, including bone healing is still a topic of vivid discussion. We aimed to investigate whether in patients with long bone fractures the presence of head injury is associated with excessive callus formation. Data on patients with head injury and femoral diaphyseal fracture admitted to our trauma unit between 1997- 2002 were collected and analysed. Patients with factors that could influence bone healing such as smoking, NSAIDs and hormonal disorders were excluded. The severity of head injury was quantified using GCS, AIS and CT scan reports. Patients matched for age, sex and ISS with femoral shaft fractures and no head injury formed the control group of the study. All the fractures were stabilised with reamed femoral nail. The quantification of fracture healing response was estimated by taking the radiological ratio of the largest diameter of callus formed into two planes and the adjacent normal diameter of femoral canal. The minimum follow-up of the patients was 12 months. In total 42 patients were studied, 17 with head injury and femoral fracture and 25 with an isolated femoral fracture, (control group). Both groups were comparable in terms of age, sex, ISS. The difference between the mean callus to diaphyseal ratio was statistically significant for both the AP and Lateral projections (AP – mean difference 0.462, 95% CI 0.312 to 0.602, p<0.0001, LAT – mean difference 0.289, 95% CI 0.142 to 0.436, p<0.001) with the head injured patients having more florid callus compared to the control group. This study supports the view that head injury leads to exuberant callus formation in patients with long bone fractures. The mechanisms of this response could be both central and local. Research is ongoing to elucidate the pathways involved in this biological phenomenon

Lengthening of the humerus is now an established technique. We compared the complications of humeral lengthening with those of femoral lengthening and investigated whether or not the callus formation in the humerus proceeds at a higher rate than that in the femur. A total of 24 humeral and 24 femoral lengthenings were performed on 12 patients with achondroplasia. We measured the pixel value ratio (PVR) of the lengthened area on radiographs and each radiograph was analysed for the shape, type and density of the callus. The quality of life (QOL) of the patients after humeral lengthening was compared with that prior to surgery. The complication rate per segment of humerus and femur was 0.87% and 1.37%, respectively. In the humerus the PVR was significantly higher than that of the femur. Lower limbs were associated with an increased incidence of concave, lateral and central callus shapes. Humeral lengthening had a lower complication rate than lower-limb lengthening, and QOL increased significantly after humeral lengthening. Callus formation in the humerus during the distraction period proceeded at a significantly higher rate than that in the femur. . These findings indicate that humeral lengthening has an important role in the management of patients with achondroplasia

Abstract. Introduction. Vitamin D deficiency in the UK is well documented − 30–40% of the population. It is an essential component of calcium metabolism and adequate levels are important for bone healing. Studies have demonstrated an overall prevalence of vitamin D deficiency/insufficiency at 77% in trauma patients aged >18, deficiency alone was 39%. Adequate vitamin D levels have a positive effect on bone mineral density and callus formation at fracture sites. Methods. We conducted a retrospective consecutive case series of all patients aged 0–50 undergoing surgical management for any fracture in October 2021 to March 2022. We assessed if vitamin D levels were checked and if patients were prescribed replacement as per local guidelines. Results. A total of 131 patients were identified, (mean 29 years; 83 male and 48 female). Most cases were upper limb fractures (n=78, 60%), as opposed to lower limb (n=53, 40%). Only 20 (15%) had their levels checked, of which 13 (65%) were insufficient/deficient (10 insufficiency, 2 deficiency, 1 severe deficiency). Of these 13 patients, only 3 (23%) were prescribed replacement therapy. Conclusions. Only a small proportion of patients had their levels checked, however the majority were insufficient/deficient. The prevalence in our study is consistent with larger epidemiology studies, which reflect a higher rate of deficiency in fracture patients compared to the general population. Thus, we propose that all patients in this age group should undergo a vitamin d level check upon time of clerking and this should be accurately treated as per trust guidance

Introduction. Total hip arthroplasty (THA) using short design stem is surging with increasing movement of minimally invasive techniques. Short stems are easier to insert through small incisions preserving muscles. We have used these types of short stems since 2010. Almost all of the patients have shown good clinical results. However, two patients developed fatigue fractures on femurs post operatively. We have reviewed the clinical and radiographic results of these patients. Patients and methods. From April 2010, we have performed 621 THAs with short design stems, Microplasty. R. , Biomet, using a muscle preservation approach, the Direct Anterior Approach (DAA). The age ranged from 31 to 88 years old. Case1: 56y.o. male, BMI 23.1kg/m. 2. Preoperative diagnosis was bilateral osteoarthritis. Simultaneous THAs were performed on bilateral hips. He was allowed to bear as much weight as he could tolerate using an assistive device immediately after surgery, and followed standard hip precautions for the first 3 weeks. He was discharged from hospital seven days after surgery and returned to his job two weeks after surgery. He noticed sudden left thigh pain three weeks after surgery without any obvious cause. Crutches were recommended to partially bear his weight. Six weeks after surgery, a fracture line became visible on the radiographs and new callus formation also became visible. Three months after surgery, he felt no pain and was able to walk without any crutches. Case2: 66y.o. female, BMI 27.5 kg/m. 2. Preoperative diagnosis was bilateral osteoarthritis. THAs were performed on the hips at a six month interval. The right hip was operated on first, followed by the left hip. She was discharged from hospital four days after surgery and returned to her job six weeks after surgery. Two months later after left hip surgery, she suddenly felt pain on her left femur without any obvious cause, and was unable to walk. Three weeks later, X-rays showed fatigue fracture lines and new callus formations. After two or three months using crutches, her pain improved and X-rays showed good callus formation and no stem subsidence. Discussions. Several reports showed insufficiency fractures of the pelvis following THA. But most of them occurred due to repetitive stress on fragile bones. But our cases showed no evidence of osteoporosis. They had no history of trauma. But they had some points in common, which were they were bilateral cases and their BMI were not low. The incident rate of fatigue fractures of femur with this short stem THAs was 0.3% in our cases. We suggested that one of the causes of these fatigue fractures was the shortness of the stems. The shortness of the stems concentrate the body weight to limited contact area of the femur, and the stress causes the fatigue fractures. We should consider the risk of fatigue fractures on the patients who are operated on bilaterally. However these two patients showed good callus formations and no stem subsidence after a few weeks of partial weight bearing

Aim. Debridement, Antibiotics, Irrigation, and implant Retention (DAIR) is a surgical treatment protocol suitable for some patients with fracture related infection (FRI). Clinically relevant pre-clinical models of DAIR are scarce and none have been developed in large animals. Therefore, this project aimed to develop a large animal model for FRI including a DAIR approach and compare outcomes after 2 or 5 weeks of infection. Method. Swiss Alpine sheep (n=8), (2–6 years, 50–80 kg) were included in this study. This study was approved by cantonal Ethical authorities in Chur, Switzerland. A 2 mm osteotomy was created in the tibia and fixed with a 10-hole 5.5 mm steel plate. Subsequently, 2.5 mL of saline solution containing 10. 6. CFU/mL of Staphylococcus aureus MSSA (ATCC 25923) was added over the plate. Sheep were observed for 2 (n=3) or 5 weeks (n=5) until revision surgery, during which visibly infected or necrotic tissues were removed, and the wound flushed with saline. All samples were collected for bacterial quantification. After revision surgery, the sheep were treated systemically for 2 weeks with flucloxacillin and for 4 weeks with rifampicin and cotrimoxazole. After 2 further weeks off antibiotics, the animals were euthanized. Bacteriological culture was performed at the end of the study. Bone cores were isolated from the osteotomy site and processed for Giemsa & Eosin and Brown and Brenn staining. A radiographical examination was performed every second week. Results. Bacteriological evaluation of the retrieved samples during revision surgery showed no significant difference between the 2 vs 5 weeks infection periods in term of total CFU counts. At the end of the study, radiographical examination showed callus formation over the osteotomy site in both groups, although the osteotomy was not completely healed in either group. At euthanasia, the 2 weeks infection group showed a higher soft tissue burden compared to the 5 weeks group, whereby the infection in the 5 weeks group was primarily located in the bone and bone marrow. Conclusions. The large animal model of FRI and DAIR was successfully established. Bacteriological outcomes highlight that the increasing duration of the infection does not change the outcome but the location of the infection from a predominantly soft tissue infection to a deeper bone and intramedullary (IM) channel infection. The debridement of the IM channel could potentially reduce the infection burden by eliminating those bacteria not easily reached by systemic antibiotics, though is not practical using conventional techniques

It has been previously shown that Low-Magnitude High-Frequency Vibration (LMHFV) is able to enhance ovariectomy-induced osteoporotic fracture healing in rats. Fracture healing begins with the inflammatory stage, and all subsequent stages are regulated by the infiltration of immune cells such as macrophages and the release of inflammatory cytokines including tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and interleukin-10 (IL-10). Therefore, the aim of this study was to investigate the effect of LMFHV treatment on the inflammatory response in osteoporotic fracture healing. In this study, ovariectomy-induced osteoporotic and sham-operated closed-femoral fracture SD-rats were randomized into three groups: sham control (SHAM), ovariectomized control (OVX-C) or ovariectomized vibration (OVX-V) (n=36, n=6 per group per time point). LMHFV (35Hz, 0.3g) was given 20 min/day and 5 days/week to OVX-V group. SHAM operation and ovariectomy were performed at 6-month and closed femoral fracture was performed at 9-month. Callus morphometry was determined by callus width from weekly radiography. Local expressions of inducible nitric oxide synthase (iNOS) (macrophage M1 marker), CD206 (macrophage M2 marker), TNF-α, IL-6 and IL-10 were detected by immunohistochemistry and quantified by colour threshold in ImageJ, assessed at weeks 1 and 2 post-fracture. Significant difference between groups was considered at p≤0.05 by one-way ANOVA. Callus formation was higher in OVX-V than that of OVX-C as shown by callus width at weeks 1 and 2 (p=0.054 and 0.028, respectively). Immunohistochemistry results showed that CD206 positive signal and the M2/M1 ratio which indicates the progression of macrophage polarization were significantly higher in OVX-V rats (p=0.053 and 0.049, respectively) when compared to OVX-C at week 1. Area fraction of TNF-α positive signal was significantly higher in SHAM and OVX-V rats at week 1 (p=0.01 and 0.033, respectively). IL-6 signal was also significantly higher in SHAM and OVX-V groups at week 1 (p=0.004 and 0.029, respectively). IL-10 expression was significantly lower in SHAM and OVX-V groups at week 1 (p=0.013 and 0.05, respectively). Here we have shown that LMHFV treatment promoted the shift from pro-inflammatory stage towards anti-inflammatory stage earlier. It has been reported that the polarization of pro-inflammatory macrophages M1 to anti-inflammatory macrophages M2 was indicative of the endochondral ossification process in the long bone fracture model. Besides, we found that LMHFV treatment enhanced pro-inflammatory markers of TNF-α and IL-6 and suppressed anti-inflammatory marker of IL-10 at week 1, showing that inflammatory response was enhanced at week 1 post-fracture. These inflammatory cytokines involved in fracture healing were shown to coordinate different fracture healing processes such as mesenchymal stem cell recruitment and angiogenesis. Our previous study has demonstrated that ovariectomized rats exhibit lower levels of inflammatory response after fracture creation. Therefore, we report that LMHFV treatment can modulate macrophage polarization from M1 to M2 at an earlier time-point and partly restore the impaired inflammatory response in OVX bones at the early stage of fracture healing that may lead to accelerated healing of osteoporotic fracture as shown by promoted callus formation

Aim. Treatment of infected and non-infected non-unions remain a major challenge after orthopedic fracture-related surgery. In clinical practice, several revision surgeries are usually required, including a radical debridement and exchange of implants, to control or even eradicate the infection to finally achieve bone healing. However, a clear treatment algorithm in clinical practice may be difficult to follow due to the heterogeneous patient population. Thus, so controlled settings for research purposes is better achieved in standardized animal studies. So far, there exists no multi-stage animal model that can be realistically transferred to the clinical situation in humans. The importance of such a model is obvious in order to be able to investigate different therapy concepts for infected and non-infected non unions. Methods. In 20 female Sprague-Dawley rats, a critical size defect by a femur osteotomy with 5 mm width was done. The periosteum at the fracture zone was cauterized proximal and distal to the osteotomy to achieve an hypovascularized situation. After randomization, 10 animals were intramedullary infected with a multisensible Staph. aureus strain (10. 3. CFU). After 5 weeks, a second surgery was performed with removing the K-wire, debridement of the osteotomy-gap and re-osteosynthesis with an angle-stable plate. After further 8 weeks all rats were euthanized and underwent biomechanical testing to evaluate bone consolidation or delayed union, respectively. Additional micro-CT analysis, histological, and histomorphometric analysis were done to evaluate bone consolidation or delayed union, respectively, by the score of Lane and Sandhu and to quantify callus formation and the mineralized area of the callus. Results. 5 weeks after the first surgery a non-union had formed in all septic and aseptic animals. According to the Lane and Sandhu score a significantly higher callus formation was found in the infected group. In all infected animals, the inoculated Staph. aureus strain was detected during the revision surgery. 8 weeks after the second surgery no bone healing could be detected in the µ-CT analysis in both groups and biomechanical testing showed a significant lower maximum torque in both groups as compared to the untreated contralateral femura. Conclusion. Here we show first results of a new two-stage pseudarthrosis animal model, which reflects a very realistic clinical situation of an infection-related non-union model. Based on this model, various therapeutic strategies in the treatment of infectious and non-infectious pseudarthrosis, such as the use of bone substitutes, can be evaluated in further studies

Aim. Staphylococcus aureus is the leading pathogen in fracture-related infection (FRI). Virulence factors vary between different strains, which may have a decisive influence on the course of infection. Previous in vitro experiments, in vivo testing in wax moth larvae, and genomic analysis of S. aureus isolates from FRI identified a low- and high-virulent strain. These findings correlated with the acute course of FRI induced by the high-virulent pathogen, whereas the low-virulent strain caused a chronic FRI in its human host. However, the role of bacterial virulence in FRI is not completely understood. Therefore, the present study aimed to compare the identified high- and low-virulent S. aureus isolates in a murine FRI model. Method. Skeletally mature C57Bl/6N mice received a femoral osteotomy stabilized by titanium locking plates. FRI was established by inoculation of either high-virulent S. aureus EDCC 5458 or low-virulent S. aureus EDCC 5464 in the fracture gap. Mice were euthanized 4 and 14 days after surgery, respectively. Severity and progression of infection were assessed in terms of clinical presentation, quantitative bacteriology, semiquantitative histopathologic evaluation, and serum cytokine profile. Results. Quantitative bacteriological results 4 days after surgery revealed a higher bacterial load in soft tissue samples in high-virulent infected animals (p =0.026). Mice infected with the high-virulent strain also displayed higher rates of organ dissemination (24/36 organs in high-virulent, versus 5/36 organs in low-virulent infected animals; p <0.0001). In the histopathological assessment, bacterial agglomerations at the fracture ends were present to a greater extent in the high-virulent cohort and barely detectable in low-virulent infected mice. In both cohorts, no bone healing was observed after 4 days. On day 14, bone healing at the fracture site was visible in low-virulent infected animals, whereas callus formation was observed in only one animal from the high-virulent infected cohort. Furthermore, osteonecrosis and osteolysis were increased in high-virulent infected animals. Regarding serum cytokines, innate immune markers were elevated in both groups at day 4. By day 14, a more pronounced proinflammatory response indicated by increased serum cytokine levels of IFN-γ, IL-1β, and IL-6 was observed in high-virulent infected animals. Conclusions. The present study demonstrated distinct bacteriological and histopathological differences between two different virulent S. aureus strains previously shown to have different courses in human patients. While host physiology is often considered to have a major impact on the course of FRI, this study highlights the critical influence of the invading pathogen and its virulence characteristics

Background:. In recent times there has been an increasing trend towards surgical intervention in paediatric femoral shaft fractures with widening indications. Titanium elastic nails and external fixation are two widely practiced procedures for such fractures. Materials & Methods:. We report a series of 48 children with 52 fractured femurs, 18 being managed by TENS and 34 in a linear external fixator. Children were aged between 3.5 to 12 years and the fractures were stabilised after an optimal closed reduction on a normal theatre table under image intensifier control. Fracture site distribution was nearly uniform in both the groups. Though most children were assigned to any of the groups at random, external fixators were applied on many younger children and those having financial constraints. Results:. The average age of children in the TENS group was 7.4 years and the average fracture healing time was 9.4 weeks. In the ex-fix group the figures were 5.6 years and 8.6 weeks respectively. Fixators were removed when good callus formation was seen on at least three cortices; average fixator time was 7.5 weeks. Fracture callus formation was slower in TENS group. Soft-tissue irritation at the nail entry points was the commonest complication for the TENS whereas pin-track infection was problem in the ex-fix group. Conclusion:. Management of paediatric femoral shaft fractures has changed to include more interventions. Flexible or elastic nailing like the TENS is a versatile and popular technique, however stabilisation in an external fixator also produce comparable results. External-fixation is an easier, cheaper and shorter procedure, and a mini ex-fix becomes a convenient external splint for smaller children who can be more conveniently nursed. Moreover ex-fix removal is an office procedure without anaesthesia

Aim. To evaluate the efficacy of bone marrow derived stromal cells (BMSC) for the treatment of non-unions in fractures. Methods. An ethically approved single centre randomised control trial recruited 35 patients for treatment of non-unions with BMSC during 2006–2010. Autologous BMSC were culture expanded at the Good Manufacturing Practice (GMP) standard Oscell® laboratory in the hospital. Following in vitro expansion- cells in autologous serum and serum alone were 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 six 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. The study had 21 males and 14 females with a mean age of 51.2±13.2 years (range 18–76). The average duration of non-union was 3±2 years (range 1–10 years) with mean 3.5 (range 1–12) surgical interventions prior to BMSC insertion. Independent assessment of ‘test’ and ‘control’ side revealed that the callus formation and fracture bridging was slow although a trend to improvement on the side of the BMSC insertion was observed at 9–12 months. At final follow-up 22 patients progressed to bony union; 13 patients had persisting non union. Conclusion. BMSC can achieve progression to union in substantial number of cases of resistant non-unions where the alternative is extensive reconstructive procedures or amputations. Larger trials are required to study the pattern of early healing following cell therapy in such cases

We report the results of using a combination of fixator-assisted nailing with lengthening over an intramedullary nail in patients with tibial deformity and shortening. Between 1997 and 2007, 13 tibiae in nine patients with a mean age of 25.4 years (17 to 34) were treated with a unilateral external fixator for acute correction of deformity, followed by lengthening over an intramedullary nail with a circular external fixator applied at the same operating session. At the end of the distraction period locking screws were inserted through the intramedullary nail and the external fixator was removed. The mean amount of lengthening was 5.9 cm (2 to 8). The mean time of external fixation was 90 days (38 to 265). The mean external fixation index was 15.8 days/cm (8.9 to 33.1) and the mean bone healing index was 38 days/cm (30 to 60). One patient developed an equinus deformity which responded to stretching and bracing. Another developed a drop foot due to a compartment syndrome, which was treated by fasciotomy. It recovered in three months. Two patients required bone grafting for poor callus formation. We conclude that the combination of fixator-assisted nailing with lengthening over an intramedullary nail can reduce the overall external fixation time and prevent fractures and deformity of the regenerated bone

Aim. Silver is known for its excellent antimicrobial activity, including activity against multiresistant strains. The aim of the current study was to analyze the biocompatibility and potential influence on the fracture healing process a silver-coating technology for locking plates compared to silver-free locking plates in a rabbit model. Methods. The implants used in this study were 7-hole titanium locking plates, and plasma electrolytic oxidation (PEO) silver coated equivalents. A total of 24 rabbits were used in this study (12 coated, 12 non-coated). An osteotomy of the midshaft of the humerus was created with an oscillating saw and the humerus stabilized with the 7 hole locking plates with a total of 6 screws. X-rays were taken on day 0, week 2, 4, 6, 8, and 10 for continuous radiographical evaluation of the fracture healing. All animals were euthanized after 10 weeks and further assessment was performed using X-rays, micro-CT, non-destructive four-point bending biomechanical testing and histology. Furthermore, silver concentration was measured in the kidney, liver, spleen and brain. Results. X-rays showed normal undisturbed healing of the osteotomy in all animals without any differences between the two groups over the entire X-ray analysis over 10 weeks (Figure 1). Callus formation was observed up to week 4 to 5 followed by callus remodeling after 6 weeks indicating physiological fracture healing pattern in both the silver and in the silver free group. Micro CT analysis revealed overall tissue (callus and cortical bone) volume as well as tissue density to be comparable between the two groups. Mechanical testing showed comparable stiffness with an average stiffness relative to contralateral bones of 75.7 ± 16.1% in the silver free control group compared to 69.7 ± 18.5% (p-value: 0.46). Histology showed no remarkable difference in the analysis of the healed osteotomy gap or in the surrounding soft tissue area. Silver content was found to be close to baseline values without differences between the two groups. Conclusions. This study shows that the presented antimicrobial silver surface modification for locking plates has a good biocompatibility without any negative influence on the fracture healing processes compared to the silver free control group. This allows for further clinical investigation of this silver technology for locking plates in fracture patients with an elevated infection risk, e.g. in patients with open fractures. For any figures or tables, please contact the authors directly

Aim. Treatment regimens for fracture-related infection (FRI) often refer to the classification of Willenegger and Roth, which stratifies FRIs based on time of onset of symptoms. The classification includes early (<2 weeks), delayed (2–10 weeks) and late (>10 weeks) infections. Early infections are generally treated with debridement and systemic antibiotics but may not require implant removal. Delayed and late infections, in contrast, are believed to have a mature biofilm on the implant, and therefore, treatment often involves implant removal. This distinction between early and delayed infections has never been established in a controlled clinical or preclinical study. This study tested the hypothesis that early and delayed FRIs respond differently to treatment comprising implant retention. Method. A complete humeral osteotomy in 16 rabbits was fixed with a 7-hole-LCP and inoculated with Staphylococcus aureus. The inoculum size (2×106 colony forming units per inoculum) was previously tested without antibiotic intervention to result in infection of all animals persisting for at least 12 weeks.4 The infection was allowed to develop for either 1 (early group) or 4 (delayed group) weeks (n= 8 per group) after bacterial inoculation. At these time points, treatment involved debridement and irrigation of the wound (no implant removal) and quantitative bacteriological evaluation of the removed materials. Systemic antibiotics were administered according to a common clinical regimen (2 weeks: rifampin + nafcillin, followed by 4 weeks: rifampin + levofloxacin). After an additional one-week antibiotic washout period, animals were euthanized and a quantitative bacteriology of soft tissue, implant (after sonication) and bone was performed. Results. Greater numbers of bacteria were recovered by debridement and irrigation in the early group compared with the delayed group, which may indicate retraction of the infection in the delayed stage. Treatment was successful in both the early and delayed group: all animals in both groups were infection free at euthanasia. Furthermore, all osteotomies had healed, although animals in the delayed group displayed irregular callus formation. Conclusions. In both groups, treatment successfully eradicated the infection, suggesting that, at least in this model, the maturity of the infection does not impact upon treatment success within the first four weeks. Acknowledgements. This work was funded by AOTrauma

The forefoot is affected less frequently than the hindfoot in rheumatoid patients but comes to surgical reconstruction more frequently. The classical rheumatoid deformities of hallux valgus and clawed lesser toes are made more painful with destructive arthritis, plantar prominence of metatarsal heads and callus formation. Rheumatoid forefoot reconstruction has not changed dramatically over the last three decades and has been reliably efficacious. However subtle technique changes and implant improvements have helped to keep this operation reproducible and beneficial for rheumatoid patients

Background. Implants based on the polyetheretherketon (PEEK) polymer have been developed in the last decade as an alternative to conventional metallic devices. PEEK devices may provide several advantages over the use of conventional orthopedic materials, including the lack of metal allergies, radiolucency, low artifacts on magnetic resonance imaging scans and the possibility of tailoring mechanical properties. The purpose of this study was to evaluate the clinical results at mean 24-month follow-up using a new plate made of carbon-fiber-reinforced polyetheretherketon (CFR-PEEK) for the treatment of distal radius fractures. Materials and methods. We performed a prospective study including all patients who were treated for unstable distal radius fracture with a CFR-PEEK volar fixed angle plate. We included 70 consecutive fractures of AO types B and C that remained displaced after an initial attempt at reduction. The fractures were classified according to the AO classification: 35 fractures were type C1, 13 were type C2, 6 were type C3, 5 were type B1 and 11 were type B2. Results. All fractures healed, and radiographic union was observed at an average of 6 weeks. The final Disabilities of Arm, Shoulder and Hand score was 5.2 points. The average grip strength, expressed as a percentage of the contralateral limb, was 94 %. Three cases of hardware breakage were reported. Two cases were due to intraoperative plate rupture caused by the attempt to achieve the reduction of the fracture in 1 case and while inserting a distal screw in the other case. In the last case hardware breakage was caused by a fall on the injuried arm 1 week after surgery. No cases of loss of the surgically achieved fracture reduction were documented. Hardware removal was performed in 3 cases, for the occurrence of extensor tenosynovitis in 2 patients and tenosynovitis of flexor pollicis longus in 1 case. Conclusion. The major advantage of CFR-PEEK plate is its radiolucency. This characteristic allows direct visualization of osseous callus formation, allowing monitoring of the healing of the fracture, thereby improving clinical assessment and accuracy. Therefore, specific indications for this new radiolucent plate can be represented by fractures with significant metaphyseal comminution and in cases of nascent malunion where a distal radius osteotomy with bone grafting is usually performed to correct the wrong angle. At early follow-up this device showed good clinical results and allowed maintenance of reduction in complex, AO fractures. The occurrence of tendon complications related to this implant was similar to that reported in literature for the other new-generation plates. However, attention should be payed when stressing the plate to achieve the desired fracture reduction to avoid hardware failure

Gold standard for the management of non-union is open surgical debridement, stabilisation, and autologous bone grafting. LIPUS is becoming more popular, yet the evidence is still inconclusive. LIPUS involves the use of ultrasound at the fracture site with little risk to the patient. The purpose of this study was to assess effectiveness and cost benefit of LIPUS in the management of non-unions post sustaining an open fracture. We retrospectively reviewed 29 patients with open fractures with established non-union undergoing LIPUS since 2010 (4 females, mean age 48) range 3–27 months, mean 9 months, either post injury or last intervention. All were tertiary referrals, sustaining injuries to the following areas; Tibial 21, Femur 6, Humerus 2, Radius 1. Definitive fixation being; 9 TSF's, 11 IMN's, 9 plates. (undergoing a mean 2.4 procedures). Aside from sustaining an open fracture, 7 had risk factors for non-unions 5 smokers, 2 NSAID's. Failure of treatment was based on undertaking bone grafting. In 28 patients (1 lost to follow up) union was achieved in 71% (mean 157 days). All were screened for infection, 4 had organisms on enrichment culture. 8 (5 Gustillo Anderson Grade 3A/B) injuries did not show evidence of callus formation, LIPUS was discontinued and grafting performed. Open fractures were graded as; 7 Grade 1, 4 Grade 2, 8 Grade 3A, 10 Grade 3B being received. Of these; 20 underwent primary closure, 6 free flaps and 3 SSG. The cost of LIPUS is approx £2500, compared bone grafting using autologous iliac crest graft with no medical comorbidities of £3715. This case series further supports union rates after LIPUS. Cost and morbidity benefit of utilising LIPUS over opting for bone grafting initially is £1215 per patient. Whilst autologous bone grafting is currently the gold standard, it is not without morbidity. We achieved union rates of 71% despite a number of patients having recognised risk factors, showing that LIPUS is a useful resource in the management of non-union

To elucidate the molecular biology of fracture healing, murine models are preferred. We performed a study with the first internal fixation system that allows studying murine fracture healing in a controlled mechanical environment, to characterise the timing of the fracture healing cascade with this model, based on a histological evaluation. Femoral osteotomies were performed in 68 male C57BL/six mice and stabilised with locking internal fixation plates in either stiff, or defined, flexible configurations. Healing progression was studied at 10 time points between 3 and 42 days post- surgery. After surgery, mice were radiographed to confirm the correct implant positioning. After sacrifice, the extracted femora were processed for decalcified histology. Thin sections were taken as serial transverse sections and stained for subsequent histomorphometric analysis and three-dimensional reconstruction of the different fracture callus tissues. The surgery was successful in 62 animals. Only six6 (8.8%) animals had to be sacrificed due to complications during surgery. The post-operative radiographs demonstrated a high reproducibility of implant positioning and no implant failure or screw loosening occurred during the experimental period. The improved consistency in surgical technique leading to more uniform results represents a key advantage of this system over other mouse fracture healing models. As such, it may allow a reduction in the sample size needed in future murine fracture healing studies. The histological evaluation confirmed the lack of a periosteal callus, and exclusively endosteal, intramembraneous bone formation in the bones stabilised with the stiff implants. The bones that were stabilised with the more flexible internal fixation plates showed additional endochondral ossification with extensive, highly asymmetrical, periosteal callus formation. Our results demonstrate that this murine fracture model leads to different healing patterns depending on the flexibility of the chosen plate system. This allows researchers to investigate the molecular biology of fracture healing in different ossification modes by selection of the appropriate fixation

Treatment of large segmental defects in the extremities is challenging. A segmental tibial defect model in a large animal can provide a basis through which in vivo testing of materials and techniques for use in non-unions and severe trauma cases can be examined. This study reports such a model. Six aged ewes (> 5 years) were used following ethical approval. A 5cm piece of the mid diaphysis of the left tibia was removed including its associated periosteum. The tibia was stabilized with an 8mm stainless steel cross locked intramedullary nail and all tissues closed in their respective layers. Animals were euthanised at 12 weeks following surgery and evaluated using radiographic, micro-computed tomography (CT), soft tissue and hard tissue histology techniques. Three weeks post operatively one of the intramedullary nails failed through the first of the distal two cross locking screw holes, the sheep was euthanised and the tibia was harvested. Early signs of callus formation were evident at the osteotomy edges originating from the periosteal surface; the defect space was bridged by fibrous scar tissue. The remaining 5 sheep were taken out to the 12 week time point then all relevant tissues were harvested. Gross dissection revealed a lack of bony union in the defect site and no evidence of infection. X-rays and CT showed a lack of hard tissue callus bridging in the defect region at 12 weeks. Histological sections of the bridging tissues revealed, callus originating from both the periosteal and endosteal surfaces, with fibrous tissue completing the bridging in all instances. One case had cartilaginous tissue developing; however this was incomplete at 12 weeks. As none of the 12 week time point sheep achieved clinical union; this model may be effective as a basis for the investigation of healing adjuncts to be used in non-union cases, where severe traumatic injury has lead to significant bone loss such as blast injuries or following large tumour removal

Introduction. Osteosynthesis with open reduction techniques in comminuted subtrochanteric femoral fractures can further devitalise fragments and lead to increased rate of non-union, infection, and implant failure. Therefore, these fractures require indirect reduction techniques that do not further damage the vascular supply or soft tissue attachments of the fragments. Dynamic condylar screw (DCS) using indirect reduction and minimally invasive technique may be a good alternative to avoid these complications in such fractures. Material & methods. Forty-three patients with comminuted subtrochanteric fractures underwent indirect reduction and biological internal fixation with DCS. Mean age was 43.9 (range 25–65) years. There were six Seinsheimer type III, 15 type IV and 22 type V fractures. Results. All fractures united without bone grafting at average union time of 16.16 weeks (range, 13–22) weeks. There were no cases of non-union or implant failure at mean follow-up of 25.13 months. We observed technical difficulties in six patients such as: inaccurate placement of guide pin in two patients, difficulty in sliding the plate due to obesity in one patient, difficulty in gliding barrel plate over condylar screw in one patient and technical failure in a further two patients. Seven patients had mean limb length discrepancy of 1.48 cm (range, 1–2). Mean Harris hip score was 88.2 (range 80–90) points. Two patients had coxa vara and persistent limp. Discussion. Stripping of the soft tissues to the lateral cortex is kept to a minimum in indirect reduction. The vitality of the medial fragments is not further compromised since they are not exposed. Viable bone rapidly unites by callus formation. Conclusions. Osteosynthesis of comminuted subtrochanteric fractures is desirable using indirect reduction and minimally invasive technique. Dynamic condylar screw can be used based on these principles; however, proper planning and execution of the technique is required to achieve good functional outcome and to avoid complications

Purpose. Angiogenesis and osteogenesis are essential for bone growth, fracture repair, and bone remodeling. VEGF has an important role in bone repair by promoting angiogenesis and osteogenesis. In our previous study, endothelial progenitor cells (EPCs) promoted bone healing in a rat segmental bone defect as confirmed by radiological, histological and microCT evaluations (Atesok, Li, Schemitsch 2010); EPC treatment of fractures resulted in a significantly higher strength by biomechanical examination (Li, Schemitsch 2010). In addition, cell-based VEGF gene transfer has been effective in the treatment of segmental bone defects in a rabbit model (Li, Schemitsch et al 2009); Purpose of this study: Evaluation of VEGF gene expression after EPC local therapy for a rat segmental bone defect. Method. Rat bone marrow-derived EPCs were isolated from the rat bone marrow by the Ficoll-paque gradient centrifuge technique. The EPCs were cultured for 7 to 10 days in endothelial cell growth medium with supplements (EGM-2-MV-SingleQuots, Clonetics). and collected for treatment of the rat segmental bone defect. EPCs were identified by immunocytochemistry staining with primary antibodies for CD34, CD133, FLK-1, and vWF. A total of fifty six rats were studied. A five millimeter segmental bone defect was created in the middle 1/3 of each femur followed by mini plate fixation. The treatment group received 1×106 EPCs locally at the bone defect and control animals received saline only. Seven control and seven EPC treated rats were included in each group at 1, 2, 3 and 10 weeks. Animals were sacrificed at the end of the treatment period, and specimens from the fracture gap area were collected and immediately frozen. Rat VEGF mRNA was measured by reverse transcriptase-polymerase chain reaction (RT-PCR) and quantified by VisionWorksLS. All measurements were performed in triplicate. Results. Cultured EPCs at 1 week showed positive staining for CD34, CD133, Flk-1 and vWf markers. The EPC group had a greater VEGF expression than the control group at week 1, 2 and 3 but not at week 10. Three VEGF isoforms were detected in this rat model: VEGF120, VEGF164 and VEGF188. VEGF120 and VEGF164 levels peaked at two weeks, while VEGF188 levels peaked at three weeks. All three VEGF isoform levels were low at ten weeks. Conclusion. EPC-based therapy for a segmental bone defect results in increased VEGF expression during the early period of fracture repair. In addition, the specific VEGF isoform may be a key regulator of the bone healing process. These findings demonstrate that EPCs promote fracture healing by increasing VEGF levels and thus stimulating angiogenesis, a process that is essential for early callus formation and bone regeneration