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.
Large bone defects still challenge the orthopaedic surgeon. Local vascularity at the site of the fracture has an important influence on the healing procedure. Vascular endothelial growth factor (VEGF) and it's receptor (VEGFR2) are potent inducer of angiogenesis during the fracture healing. Aim of the present study was the investigation of critical size fracture (CSF) healing in VEGFR2-luc mice using tailored scaffolds. CSFs were performed and stabilised in mouse femur using an external fixator. The fracture was bridged using a synthetic 3D printed scaffold with a defined porosity to promote regeneration. The ß-tricalciumphosphate (ßTCP) and strontium doped ß-tricalciumphosphate (ßTCP+Sr) scaffolds were investigated for their regenerative potential. The expression levels of VEGFR2 could be monitored non-invasively via in vivo bioluminescence imaging for 2 months. After the longitudinal measurements the animals were euthanised for an in depth histological endpoint analysis. The different scaffold induced tissue regeneration was quantified for both, the ßTCP and the ßTCP+Sr group.Background
Methods
Unstable intertrochanteric hip fractures (AO 31A2) continue to be a challenge, as non-locking implants have shown a considerable rate of loss of reduction. Intramedullary fixation has been recommended, although screw cut-out has been identified as problematic. This study was performed to ascertain whether treatments with the established proximal femoral nail (PFN) and the newer PFNA with blade design (proximal femoral nail antirotation) have advantages over the use of the Percutaneous Compression Plate (PCCP, developed by Gotfried). Cohort study. Between March 2003 and March 2008, 134 patients with unstable fractures were treated with a PCCP, (n=44, 78.3 yrs, ASA 2.8), a PFN (n=50, 77.2 yrs, ASA 2.8), or a PFNA (n=40, 75.8 yrs, ASA 2.6). The patients (31 PCCP, 33 PFN, 30 PFNA) were then reexamined clinically and radiologically after approximately 21 months.Introduction
Methods
Aim of this study was to find out which factors influence the outcome after both column fractures of the acetabulum. We performed a retrospective analyse of 115 patients with both column acetabular fractures. The period between the injury and follow-up ranges between 2 and 19 years, 5,7 years on average. The initial displacement, the presence of a dislocation of the hip and fractures of the femoral head were analyzed on the initial radiographs. Postoperative displacement was classified according the classification of Matta. The common classifications of Helfet (posttraumatic arthrosis), Ficat/Arlet (femur head necrosis) and Brooker (periarticular calcification) were used to radiologically classify the long term results. Statistics were performed by the Chi-square-test.Aim of the study
Methods
The additive use of an external modular device may improve dorsal compression forces in pelvic external fixation. This would improve the efficiency of indirect reduction and stabilization with an anterior pelvic external fixator. The purpose of this study was to determine the forces of the posterior pelvis achieved by a new device improving the application of a supraacetabular anterior external fixator compared with other constructs. Synthetic pelvic models were used. Complete pelvic ring instability was created by symphyseal and unilateral sacroiliac joint disruption. Four different constructs of fixation were tested. A pressure-sensitive film was placed in the sacroiliac joint. The constructs were applied in a standardized way. The maximum sacroiliacal compression loads (N) of each trial was recorded. Statistics was performed with the student t-test.Objectives
Material and Method
Overlooked compartment syndrome represents a devastating complication for the patient. Invasive compartment pressure measurement continues to be the gold standard. However, repeated measurements in uncertain cases may be difficult to achieve. We developed a new, noninvasive method to assess tissue firmness by pressure related ultrasound. Decreased tissue elasticity by means of rising compartment pressures was mimicked by infusion of saline directly into the anterior tibial compartment of 6 human specimens post mortem. A pressure transducer (Codman) monitored the pressure of the anterior tibial compartment. A second transducer was located in a saline filled ultrasound probe head to allow a simultaneous recording of the probe pressure provoked by the user. The ultrasound images were generated at 5 and 100mmHg probe pressures to detect the tissue deformity by B-mode ultrasound. The fascial displacement was measured before and after compression (d). Subsequently, increments of 5mmHg pressure increases were used to generate a standard curve (0–80mmHg), thus mimicking rising compartment pressures. The intra-observer reliability was tested using 10 subsequent measurements. A correlation was determined between d and the simulated intacompartmental pressure (ICP) in the compartment. The Pearson correlation coefficient (r) was calculated. The reliability determined by the kappa value and a regression analysis was performed.Background
Methods
Patients with bilateral femur fractures are known to be at a high risk for the Systemic Inflammatory Response Syndrome; however the impact of fracture-associated soft tissue injury in the induction of systemic inflammation following bilateral femur fracture is poorly understood. To address this, the systemic inflammatory response and remote organ dysfunction following bilateral femur fracture with various degrees of soft tissue injuries were investigated in this study. 6–8 weeks old male C57/BL6 mice (n = 4–8 animals per group) were grouped as follows: Control-group (no anaesthesia, no femoral catheterisation); Sham-group (6 hour anaesthesia, femoral catheterisation); Fx-group (6 hour anaesthesia, femoral catheterisation, bilateral femur fracture with minor soft tissue injury); Fx+STI-group (6 hour anaesthesia, femoral catheterisation, bilateral femur fracture with severe soft tissue injury). Six hours after bilateral femur fracture serum levels of IL-2, IL-4, IL-6, IL-10, IL-12, TNF-α, KC and MCP-1 were measured. Furthermore, IL-6 levels of homogenized liver tissue were assessed. Neutrophil accumulation in liver and lung was determined with a myeloperoxidase (MPO) assay. Changes in liver permeability were assessed by measuring the wet-dry-ratio. The Fx+STI-group showed significantly increased serum cytokine levels as compared to the Fx- or Sham-group. The homogenized liver tissue of the Fx+STI-group showed significantly increased IL-6 levels as compared to the Sham-group. The MPO activity in lung and liver in the Fx+STI-group was significantly increased in comparison to the Fx- or Sham-group and in the Fx-group in comparison to the Sham-group. The wet-dry-ratio of the liver was significantly increased in the Fx+STI-group as compared to the Sham-group. The degree of fracture-associated soft tissue injury appears to modify systemic inflammation following bilateral femur fracture and is able to induce remote organ dysfunction. These results may have implications that have been underestimated, thus warranting clinical follow-up studies.
An increased incidence of systemic inflammatory response syndrome was associated with three variables: presence of borderline condition, hemothorax and requirement of blood transfusion. This may have important treatment implications, including the management of major fractures.
