Aims

Impaired fracture repair in patients with type 2 diabetes mellitus (T2DM) is not fully understood. In this study, we aimed to characterize the local changes in gene expression (GE) associated with diabetic fracture. We used an unbiased approach to compare GE in the fracture callus of Zucker diabetic fatty (ZDF) rats relative to wild-type (WT) littermates at three weeks following femoral osteotomy.

We measured the stability of fixation in femoral neck fractures treated with von Bahr screws, investigated the influence of impaction and correlated peroperative stability with the clinical results. Stability was measured at operation using a metal probe fitted with strain gauges. Its tip was anchored in the subchondral bone of the femoral head and its lateral end was fixed in the lateral femoral cortex. The shearing force produced by longitudinal compression applied to the foot of the operated leg was recorded. The results in 41 consecutive patients all followed for 30 months, showed that fractures with early loosening or nonunion had all had significantly poorer stability than the fractures that had healed. Impaction improved stability in only 23 out of the 41 fractures; in the others stability had deteriorated or was unchanged

Osteosynthesis aims to maintain fracture reduction until bone healing occurs, which is not achieved in case of mechanical fixation failure. One form of failure is plastic plate bending due to overloading, occurring in up to 17% of midshaft fracture cases and often necessitating reoperation. This study aimed to replicate in-vivo conditions in a cadaveric experiment and to validate a finite element (FE) simulation to predict plastic plate bending. Six cadaveric bones were used to replicate an established ovine tibial osteotomy model with locking plates in-vitro with two implant materials (titanium, steel) and three fracture gap sizes (30, 60, 80 mm). The constructs were tested monotonically until plastic plate deformation under axial compression. Specimen-specific FE models were created from CT images. Implant material properties were determined using uniaxial tensile testing of dog bone shaped samples. The experimental tests were replicated in the simulations. Stiffness, yield, and maximum loads were compared between the experiment and FE models. Implant material properties (Young's modulus and yield stress) for steel and titanium were 184 GPa and 875 MPa, and 105 GPa and 761 MPa, respectively. Yield and maximum loads of constructs ranged between 469–491 N and 652–683 N, and 759–995 N and 1252–1600 N for steel and titanium fixations, respectively. FE models accurately and quantitatively correctly predicted experimental results for stiffness (R2=0.96), yield (R2=0.97), and ultimate load (R2=0.97). FE simulations accurately predicted plastic plate bending in osteosynthesis constructs. Construct behavior was predominantly driven by the implant itself, highlighting the importance of modelling correct material properties of metal. The validated FE models could predict subject-specific load bearing capacity of osteosyntheses in vivo in preclinical or clinical studies. Acknowledgements: This study was supported by the AO Foundation via the AOTRAUMA Network (Grant No.: AR2021_03)

Patients with bone and muscle weakness from disuse have higher risk of fracture and worse post-injury mortality rates. The goal of this current study was to better inform post-fracture rehabilitation strategies by investigating if physical remobilization following disuse by hindlimb unloading improves osteochondral callus formation compared to continued disuse by hindlimb suspension (HLS). We hypothesized that continued HLS would impair callus bone and cartilage formation and that physical rehabilitation after HLS would increase callus properties. All animal procedures were approved by the VCU IACUC. Skeletally mature, male and female C57BL/6J mice (18 weeks) underwent HLS for 3 weeks. Mice then had their right femur fractured by open surgical dissection (stabilized with 24-gauge pin). Mice were then either randomly assigned to continued HLS or allow normal physical weight-bearing remobilization (HLS + R). Mice allowed normal cage activity throughout the experiment served as controls (GC). All mice were sacrificed 14-days following fracture with 4-8 mice (male and female) per treatment. Data analyzed by respective ANOVA with Tukey post-hoc (*p< 0.05; # p < 0.10). Male and female mice showed conserved and significant decreases in hindlimb callus bone formation from continued HLS versus HLS + R. Combining treatment groups regardless of mouse sex, histological analyses using staining on these same calluses demonstrated that HLS resulted in trends toward decreased cartilage cross-sectional area and increased osteoclast density in woven bone versus physically rehabilitated mice. In support of our hypothesis, physical remobilization increases callus bone formation following fracture compared to continued disuse potentially due to increased endochondral ossification and decreased bone resorption. In all, partial weight-bearing exercise immediately following fracture may improve callus healing compared to delayed rehabilitation regimens that are frequently used

Standard fixation for intra-articular distal humerus fracture is open reduction and internal fixation (ORIF). However, high energy fractures of the distal humerus are often accompanied with soft tissue injuries and or vascular injuries which limits the use of internal fixation. In our report, we describe a highly complex distal humerus fracture that showed promising healing via a ring external fixator. A 26-year-old man sustained a Gustillo Anderson Grade IIIB intra-articular distal humerus fracture of the non-dominant limb with bone loss at the lateral column. The injury was managed with aggressive wound debridement and cross elbow stabilization via a hinged ring external fixator. Post operative wound managed with foam dressing. Post-operatively, early controlled mobilization of elbow commenced. Fracture union achieved by 9 weeks and frame removed once fracture united. No surgical site infection or non-union observed throughout follow up. At 2 years follow up, flexion - extension of elbow is 20°- 100°, forearm supination 65°, forearm pronation 60° with no significant valgus or varus deformity. The extent of normal anatomic restoration in elbow fracture fixation determines the quality of elbow function with most common complication being elbow stiffness. Ring fixator is a non-invasive external device which provides firm stabilization of fracture while allowing for adequate soft tissue management. It provides continuous axial micro-movements in the frame which promotes callus formation while avoiding translation or angulation between the fragments. In appropriate frame design, they allow for early rehabilitation of joint where normal range of motion can be allowed in controlled manner immediately post-fixation. Functional outcome of elbow fracture from ring external fixation is comparable to ORIF due to better rehabilitation and lower complications. Ring external fixator in our patient achieved acceptable functional outcome and fracture alignment meanwhile the fracture was not complicated with common complications seen in ORIF. In conclusion, ring external fixator is as effective as ORIF in treating complex distal humeral fractures and should be considered for definitive fixation in such fractures

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

Virtual mechanical testing is a method for measuring bone healing using finite element models built from computed tomography (CT) scans. Previously, we validated a dual-zone material model for ovine fracture callus that differentiates between mineralized woven bone and soft tissue based on radiodensity. 1. The objective of this study was to translate the dual-zone material model from sheep to two important clinical scenarios: human tibial fractures in early-stage healing and late-stage nonunions. CT scans for N = 19 tibial shaft fractures were obtained prospectively at 12 weeks post-op. A second group of N = 33 tibial nonunions with CT scans were retrospectively identified. The modeling techniques were based on our published method. 2. The dual-zone material model was implemented for humans by performing a cutoff sweep for both the 12-week and nonunion groups. Virtual torsional rigidity (VTR) was calculated as VTR = ML/φ [N-m. 2. /°], where M is the moment reaction, L is the diaphyseal segment length, and φ is the angle of twist. As the soft tissue cutoff was increased, the rigidity of the clinical fractures decreased and soft tissue located within the fracture gaps produced higher strains that are not predicted without the dual zone approach. The structural integrity of the nonunions varied, ranging from very low rigidities in atrophic cases to very high rigidities in highly calcified hypertrophic cases, even with dual-zone material modeling. Human fracture calluses are heterogeneous, comprising of woven bone and interstitial soft tissue. Use of a dual-zone callus material model may be instrumental in identifying delayed unions during early healing when callus formation is minimal and/or predominantly fibrous with little mineralization. ACKNOWLEDGEMENTS:. This work was supported by the National Science Foundation (NSF) grant CMMI-1943287

Aims. There is a lack of published evidence relating to the rate of nonunion seen in occult scaphoid fractures, diagnosed only after MRI. This study reports the rate of delayed union and nonunion in a cohort of patients with MRI-detected acute scaphoid fractures. Methods. This multicentre cohort study at eight centres in the UK included all patients with an acute scaphoid fracture diagnosed on MRI having presented acutely following wrist trauma with normal radiographs. Data were gathered retrospectively for a minimum of 12 months at each centre. The primary outcome measures were the rate of acute surgery, delayed union, and nonunion. Results. A total of 1,989 patients underwent acute MRI for a suspected scaphoid fracture during the study period, of which 256 patients (12.9%) were diagnosed with a previously occult scaphoid fracture. Of the patients with scaphoid fractures, six underwent early surgical fixation (2.3%) and there was a total of 16 cases of delayed or nonunion (6.3%) in the remaining 250 patients treated with cast immobilization. Of the nine nonunions (3.5%), seven underwent surgery (2.7%), one opted for non-surgical treatment, and one failed to attend follow-up. Of the seven delayed unions (2.7%), one (0.4%) was treated with surgery at two months, one (0.4%) did not attend further follow-up, and the remaining five fractures (1.9%) healed after further cast immobilization. All fractures treated with surgery had united at follow-up. There was one complication of surgery (prominent screw requiring removal). Conclusion. MRI-detected scaphoid fractures are not universally benign, with delayed or nonunion of scaphoid fractures diagnosed only after MRI seen in over 6% despite appropriate initial immobilization, with most of these patients with nonunion requiring surgery to achieve union. This study adds weight to the evidence base supporting the use of early MRI for these patients. Cite this article: Bone Joint J 2024;106-B(4):387–393

Aim. The treatment of fracture-related infections (FRI) focuses on obtaining fracture healing and eradicating infection to prevent osteomyelitis. Treatment guidelines include removal, exchange, or retention of the implants used according to the stability of the fracture and the time from the infection. Infection of a fracture in the process of healing with a stable fixation may be treated with implant retention, debridement, and antibiotics. Nonetheless, the retention of an intramedullary nail is a potential risk factor for failure, and it is recommended to exchange or remove the nail. This surgical approach implies additional life-threatening risks in elderly fragile hip fracture patients. Our study aimed to analyze the results of implant retention for the treatment of infected nails in elderly hip fracture patients. Methods. Our retrospective analysis included patients 65 years of age or older with an acute fracture-related infection treated with implant retention from 2012 to 2020 in 6 Spanish hospitals with a minimum 1-year follow-up. Patients that required open reduction during the initial fracture surgery were excluded. Variables included in our analysis were patient demographics, type of fracture, date of FRI diagnosis, causative microorganism, and outcome. Treatment success was defined as fracture healing with infection eradication without the need for further hospitalization. Results. A total of 48 patients were identified. Eight patients with open reduction were excluded and 11 did not complete a 1-year follow-up. Out of the 29 remaining patients, the mean age was 81.5 years, with a 21:9, female to male ratio. FRI was diagnosed between 10 and 48 days after initial surgery (mean 26 days). Treatment success was achieved in 24 patients (82.7%). Failure was objectivated in polymicrobial infections or infections caused by microorganisms resistant to antibiofilm antibiotics. Seven patients required more than one debridement with a success rate of 57%. Twelve patients had an infection diagnosed after 21 days from the initial surgery and implant retention was successful in all of them. Conclusion. Our results suggest implant retention is a valid therapeutic approach for fracture-related infection in elderly hip fracture patients treated by closed reduction and intramedullary nailing

Aim. To classify Fracture-related Infection (FRI) allowing comparison of clinical studies and to guide decision-making around the main surgical treatment concepts. Method. An international group of FRI experts met in Lisbon, June 2022 and proposed a new FRI classification. A core group met during the EBJIS Meeting in Graz, 2022 and on-line, to determine the preconditions, purpose, primary factors for inclusion, format and the detailed description of the elements of an FRI Classification. Results. Historically, FRI was classified by time from injury alone (early, delayed or late). Time produces pathophysiological changes which affect the bone, the soft-tissues and the patient general health, over a continuum. No definitive cut-off is therefore possible. Also, in several studies, time was not identified as an independent predictor of outcome. The most important primary factors were characteristics of the fracture (F), relevant systemic co-morbidities of the patient (R) and impairment of the soft-tissue envelope (I). These factors determine FRI severity, choice of treatment method and are predictors of outcome. For the fracture (F), the state of healing, the potential for bone healing and the presence or absence of a bone defect are critical factors. Co-morbidities are listed and the degree of end-organ damage is important (R). The ability to close the wound directly or the need for soft tissue reconstruction determines the impairment of the soft tissue component (I). Hence the FRI Classification was designed. The final proposal of the FRI Classification is presented here. The new classification has five stages; from simple cases of infected healed fractures, in healthy individuals with good soft tissues (Stage 1), through unhealed fractures with variable potential for bone healing (Stages 2, 3 or 4) to Stage 5, with no limb-sparing or reconstructive options. For instance, the need for a free flap (I4), over a well-healed fracture (F1), in a patient with 2 co-morbidities (R2) gives a classification of F1R2I4 for that patient. Conclusions. This novel approach to FRI classification builds on previous work in osteomyelitis, PJI and chronic medical conditions. It focusses attention on the elements of the disease which need treatment. It now requires validation in large patient cohorts. On behalf of the FRI Classification Consensus Group

Aims. There is ambiguity surrounding the degree of scaphoid union required to safely allow mobilization following scaphoid waist fracture. Premature mobilization could lead to refracture, but late mobilization may cause stiffness and delay return to normal function. This study aims to explore the risk of refracture at different stages of scaphoid waist fracture union in three common fracture patterns, using a novel finite element method. Methods. The most common anatomical variant of the scaphoid was modelled from a CT scan of a healthy hand and wrist using 3D Slicer freeware. This model was uploaded into COMSOL Multiphysics software to enable the application of physiological enhancements. Three common waist fracture patterns were produced following the Russe classification. Each fracture had differing stages of healing, ranging from 10% to 90% partial union, with increments of 10% union assessed. A physiological force of 100 N acting on the distal pole was applied, with the risk of refracture assessed using the Von Mises stress. Results. Overall, 90% to 30% fracture unions demonstrated a small, gradual increase in the Von Mises stress of all fracture patterns (16.0 MPa to 240.5 MPa). All fracture patterns showed a greater increase in Von Mises stress from 30% to 10% partial union (680.8 MPa to 6,288.6 MPa). Conclusion. Previous studies have suggested 25%, 50%, and 75% partial union as sufficient for resuming hand and wrist mobilization. This study shows that 30% union is sufficient to return to normal hand and wrist function in all three fracture patterns. Both 50% and 75% union are unnecessary and increase the risk of post-fracture stiffness. This study has also demonstrated the feasibility of finite element analysis (FEA) in scaphoid waist fracture research. FEA is a sustainable method which does not require the use of finite scaphoid cadavers, hence increasing accessibility into future scaphoid waist fracture-related research. Cite this article: Bone Jt Open 2023;4(8):612–620

Fracture nonunion is a severe clinical problem for the patient, as well as for the clinician. About 5-20% of fractures does not heal properly after more than six months, with a 19% nonunion rate for tibia, 12% for femur and 13% for humerus, leading to patient morbidity, prolonged hospitalization, and high costs. The standard treatment with iliac crest-derived autologous bone filling the nonunion site may cause pain or hematoma to the patient, as well as major complications such as infection. The application of mesenchymal autologous cells (MSC) to improve bone formation calls for randomized, open, two-arm clinical studies to verify safety and efficacy. The ORTHOUNION * project (ORTHOpedic randomized clinical trial with expanded bone marrow MSC and bioceramics versus autograft in long bone nonUNIONs) is a multicentric, open, randomized, comparative phase II clinical trial, approved in the framework of the H2020 funding programme, under the coordination of Enrique Gòmez Barrena of the Hospital La Paz (Madrid, Spain). Starting from January 2017, patients with nonunion of femur, tibia or humerus have been actively enrolled in Spain, France, Germany, and Italy. The study protocol encompasses two experimental arms, i.e., autologous bone marrow-derived mesenchymal cells after expansion (‘high dose’ or ‘low dose’ MSC) combined to ceramic granules (MBCP™, Biomatlante), and iliac crest-derived autologous trabecular bone (ICAG) as active comparator arm, with a 2-year follow-up after surgery. Despite the COVID 19 pandemic with several lockdown periods in the four countries, the trial was continued, leading to 42 patients treated out of 51 included, with 11 receiving the bone graft (G1 arm), 15 the ‘high dose’ MSC (200x10. 6. , G2a arm) and 16 the ‘low dose’ MSC (100x10. 6. , G2b arm). The Rizzoli Orthopaedic Institute has functioned as coordinator of the Italian clinical centres (Bologna, Milano, Brescia) and the Biomedical Science and Technologies and Nanobiotechnology Lab of the RIT Dept. has enrolled six patients with the collaboration of the Rizzoli’ 3rd Orthopaedic and Traumatological Clinic prevalently Oncologic. Moreover, the IOR Lab has collected and analysed the blood samples from all the patients treated to monitor the changes of the bone turnover markers following the surgical treatment with G1, G2a or G2b protocols. The clinical and biochemical results of the study, still under evaluation, are presented. * ORTHOUNION Horizon 2020 GA 733288

Abstract. Objectives. Operative management of distal humerus fractures is challenging. In the past, plates were manually contoured intraoperatively, however this was associated with high rates of fixation failure, nonunion and metalwork removal. Anatomically pre-contoured distal humerus locking plates have since been developed. Owing to the rarity of distal humeral fractures, literature regarding outcomes of anatomically pre-contoured locking plates is lacking and patient numbers are often small. The purpose of this study is to investigate the outcomes of these patients. Methods. We retrospectively identified patients with distal humeral fractures treated at our institution from 2009–2018. Inclusion criteria were patients with a distal humeral fracture, who underwent two-column plate fixation with anatomically pre-contoured locking plates. Clinical records and radiographs were reviewed to elicit outcome measures, including range of motion, complications and reoperation rate. Results. We identified 50 patients with mean age of 55 years (range 17–96 years). Mean length of follow up was 5.2 years. AO fracture classification Type A occurred most frequently (46%), followed by Type B (22%) and Type C (32%). Low energy mechanisms of injury predominated in 72% of patients. Mean time from injury to fixation was seven days. Mean range of motion at the elbow was 13–123o postoperatively. The overall reoperation rate was 22%, the majority of which required subsequent removal of prominent metalwork (18%). The incidence of nonunion, heterotopic ossification, deep infection and neuropathy requiring decompression was 2% each. Fixation failure occurred in only one patient however the fracture went on to heal. Conclusions. Previously reported reoperation rates with manually contoured plates were as high as 44%, which is twice our reported rate. Modern locking plates are no longer subject to implant failure (previously 27% reported metalwork failure rate). Likewise, heterotopic ossification and non-union have also reduced, highlighting that modern plates have significantly improved overall patient outcomes. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Aims. Postoperative malalignment of the femur is one of the main complications in distal femur fractures. Few papers have investigated the impact of intraoperative malalignment on postoperative function and bone healing outcomes. The aim of this study was to investigate how intraoperative fracture malalignment affects postoperative bone healing and functional outcomes. Methods. In total, 140 patients were retrospectively identified from data obtained from a database of hospitals participating in a trauma research group. We divided them into two groups according to coronal plane malalignment of more than 5°: 108 had satisfactory fracture alignment (< 5°, group S), and 32 had unsatisfactory alignment (> 5°, group U). Patient characteristics and injury-related factors were recorded. We compared the rates of nonunion, implant failure, and reoperation as healing outcomes and Knee Society Score (KSS) at three, six, and 12 months as functional outcomes. We also performed a sub-analysis to assess the effect of fracture malalignment by plates and nails on postoperative outcomes. Results. The rates of nonunion and reoperation in group U were worse than those in group S (25.0% vs 14.3%; 15.6% vs 5.6%), but the differences were not significant (p = 0.180 and p = 0.126, respectively). Mean KSS in group U at all follow-up periods was significantly worse that in group S (75.7 (SD 18.8) vs 86.0 (SD 8.7); p < 0.001; 78.9 (SD 17.2) vs 89.1 (SD 9.8); p < 0.001; 85.0 (SD 11.9) vs 91.1 (SD 7.2); p = 0.002, respectively). In the sub-analysis of plates, mean KSS was significantly worse in group U at three and six months. In the sub-analysis of nails, the rate of reoperation was significantly higher in group U (28.6% vs 5.8%; p = 0.025), and mean KSS at six and 12 months was significantly worse in Group U. Conclusion. To obtain good postoperative functional results, intraoperative alignment of the coronal plane should be accurately restored to less than 5°. Cite this article: Bone Jt Open 2022;3(2):165–172

Nonunions occur in situations with interrupted fracture healing process and indicate conditions where the fracture has no potential to heal without further intervention. Per definition, no healing is detected nine months post operation and there is no visible progress of healing over the last three months. The classification of nonunions as hypertrophic, oligotrophic, atrophic and pseudoarthosis, as well as aseptic or septic, identifies mechanical and biological requirements for fracture healing that have not been met. The overall treatment strategy comprises identification and elimination of the problems. However, current clinical methods to determine the state of healing are based on highly subjective radiographic evaluation or clinical examination. A data collection telemetric system for objective continuous measurement of the load carried by a bridging smart implant was developed to assess the mechanical stability and monitor bone healing in complicated fracture situations. The first results from a clinical trial show that the system is capable to offer early warning of nonunions or poor fracture healing. Nonunions are often multifactorial in nature and not just related to a biomechanical problem. Their successful treatment requires consideration of both biological and mechanical aspects. Disturbed vascularity and stability are the most important factors. Infection could be another complicating factor resulting in unpredictable long-time treatment. New technologies for monitoring of fracture healing in addition to radiographic evaluation and clinical examination seem to be promising for early detection of nonunions

Introduction and Objective. Nonunion is incomplete healing of fracture and fracture that lacks potential to heal without further intervention. Nonunion commonly presents with persistent pain, swelling, or instability. Those symptoms affect patient quality of life. It is known that using low intensity pulsed ultrasound (LIPUS) for fresh fractures promotes healing. However, effectiveness of LIPUS for nonunion is still controversial. If LIPUS is prove to be effective for healing nonunion, it can potentially provide an alternative to surgery. In addition, we can reduce costs by treating nonunion with LIPUS than performing revision surgery. Materials and Methods. The two authors carried out a systematic search of PubMed, Ovid MEDLINE, and the Cochrane Library. Meta-analysis of healing rate in nonunion and delayed union patients who underwent LIPUS was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) instruction method using a random effects model. Results. The initial search identified 652 articles. Of these, 541 were excluded on the basis of the title because they were either a review paper or covered an unrelated topic. The abstracts of the remaining 111 articles were examined further. That review resulted in a sample of 12 articles. We performed a meta-analysis with a random effects model using Open Meta Analyst software. The result of pooled effect size of healing rate was 73.4% (95%CI: 65.3–81.6%). Due to the fact that nonunion lacks potential to heal without further intervention, we suggest that the therapeutic effect of 73.4% from LIPUS is sufficiently effective. As far as we know, there are no trials comparing the therapeutic effectiveness of surgery and LIPUS, so it cannot be said which is more advantageous. However, the healing rate of revision surgery was reported between 68–96%; therefore, our result is within that range. Thus, if surgery is difficult due to complications, we can recommend LIPUS. Conclusions. Meta-analysis of healing rate of nonunion treated by low-intensity pulsed ultrasound is 73.4%, which suggests sufficient therapeutic effectiveness. Furthermore, we can say that LIPUS may provide an alternative treatment for nonunion patients who cannot tolerate revision surgery due to complications

Treatment of segmental bone defects remains a major clinical problem, and innovative strategies are often necessary to successfully reconstruct large volumes of bone. When fractures occur, the resulting hematoma serves as a reservoir for growth factors and a space for cell infiltration, both crucial to the initiation of bone healing. Our previous studies have demonstrated very clear ultrastructural differences between fracture hematomas formed in normally healing fractures and those formed in segmental bone defects. However, there is little information available regarding potential differences in the underlying gene expression between hematomas formed in normal fractures, which usually heal by themselves, and segmental bone defects, which do not. Therefore, the aim of this study was to identify differences in gene expression within hematomas collected from 0.5 mm (normal fracture) and 5 mm (segmental bone defect) fracture sites during the earliest stages of bone healing. Osteotomies of 0.5 and 5 mm in the femur of Fisher 344 rats were stabilized with external fixators (RISystem AG). After 3 days the rats were sacrificed, and the fracture hematomas were collected for RNA-sequencing. Ingenuity pathway analysis (IPA) was used to identify upstream regulators and biological functions that were significantly enriched with differentially expressed genes from the RNA-sequencing analysis. Animal procedures were conducted following the IACUC protocol of the UT Health Science Center San Antonio. Key upstream regulators of bone formation were less active (e.g. TGFB1, FGF2, SMAD3) or even inhibited (e.g. WNT3A, RUNX2, BMP2) in non-healing defects when compared to normally healing fractures. Many upstream regulators that were uniquely enriched in healing defects were molecules recently discovered to have osteogenic effects during fracture healing (e.g. GLI1, EZH2). Upstream regulators uniquely enriched in non-healing defects were mainly involved in an abnormal modulation of hematopoiesis, revealing evidence of impaired maturation of functional macrophages and cytokines (e.g. IL3, CEBPE), both essential for successful bone healing. In addition, the enrichment pattern suggested a dysregulation of megakaryopoiesis (e.g. MRTFA, MRTFB, GATA2), which directly affects platelet production, and therefore fracture hematoma formation. Remarkably, the organization of the ECM was the most significantly enriched biological function in the normally healing fractures, and implies that the defect size directly affected the structural properties within the fracture hematoma. Conversely, genes encoding important ECM components (e.g. BGN, various collagens, IBSP, TNC), cell adhesion molecules, MMPs (MMP2), and TIMPs were all significantly downregulated in non-healing defects. Our most recent findings reveal new important key molecules that regulate defect size-dependent fracture healing. Combined with our previous results, which identified structural differences in fracture hematomas from both types of defects, current findings indicate that differential expression of genes is dictated by the structural properties of the hematomas formed during early fracture healing. Consequently, creating a bioscaffold that mimics the structure of normal fracture hematomas could be the first step towards developing new orthoregenerative treatment strategies that potentiate healing of large bone defects and non-healing fractures

Introduction. We aimed to determine whether there are differences in patient-reported quality of life (QoL) outcome between local flap versus free flap. Materials and Methods. All patients admitted with lower limb open fractures were retrospectively reviewed. Patient notes were assessed for demographics, time to fracture union, wound healing and patient-reported QoL with EQ-5D-5L, alongside a novel flap assessment tool. Results. A total of 40 patients had flap reconstruction of their lower limb injury; 23 local flap (Group I) and 17 free flaps (Group II). The average length of follow-up was 33.8 months. Group I - 10 revisions of flaps (43.5%) and 14 surgical complications (60.9%). Fracture union was 171 days and wound healing 130 days. EQ-5D index and EQVAS scores were 0.709 and 79.3, respectively. Group II – 8 revision of flaps (47.1%) and 12 surgical complications (70.6%). Fracture union was 273 days and wound healing 213 days. EQ-5D index and EQ-VAS scores were 0.525 and 57.2, respectively. Aesthetic appeal - 48% Group I vs. 66% Group II. Significant differences were found between the two flap groups with higher scores for daily living in Group I (p–0.007) compared to higher overall flap ratings in Group II (p–0.049). Both groups were comparable in terms of complications, while flap congestion and dehiscence were more common with free flaps. statistical interrogation did not elicit significance (p > 0.05). Conclusions. Local flap and free flap techniques offer distinct advantages. Local flaps have a better surgical outcome and patient-reported QoL in the first few years post soft tissue reconstruction. Differences between local and free reconstructive techniques in terms of patient health and function are ameliorated in the longer term

Aims

The aim of this study is to evaluate the surgical treatment with the best healing rate for patients with proximal femoral unicameral bone cysts (UBCs) after initial surgery, and to determine which procedure has the lowest adverse event burden during follow-up.

Aims

Several previously identified patient-, injury-, and treatment-related factors are associated with the development of nonunion in distal femur fractures. However, the predictive value of these factors is not well defined. We aimed to assess the predictive ability of previously identified risk factors in the development of nonunion leading to secondary surgery in distal femur fractures.