Implementation of an integrated care programme to avoid fragility fractures of the hip in older adults in 18 Bavarian hospitals - study protocol for the cluster-randomised controlled fracture liaison service FLS-CARE.

BACKGROUND: The economic and public health burden of fragility fractures of the hip in Germany is high. The likelihood of requiring long-term care and the risk of suffering from a secondary fracture increases substantially after sustaining an initial fracture. Neither appropriate confirmatory diagnostics of the suspected underlying osteoporosis nor therapy, which are well-recognised approaches to reduce the burden of fragility fractures, are routinely initiated in the German healthcare system. Therefore, the aim of the study FLS-CARE is to evaluate whether a coordinated care programme can close the prevention gap for patients suffering from a fragility hip fracture through the implementation of systematic diagnostics, a falls prevention programme and guideline-adherent interventions based on the Fracture Liaison Services model. METHODS: The study is set up as a non-blinded, cluster-randomised, controlled trial with unequal cluster sizes. Allocation to intervention group (FLS-CARE) and control group (usual care) follows an allocation ratio of 1:1 using trauma centres as the unit of allocation. Sample size calculations resulted in a total of 1216 patients (608 patients per group distributed over 9 clusters) needed for the analysis. After informed consent, all participants are assessed directly at discharge, after 3 months, 12 months and 24 months. The primary outcome measure of the study is the secondary fracture rate 24 months after initial hip fracture. Secondary outcomes include differences in the number of falls, mortality, quality-adjusted life years, activities of daily living and mobility. DISCUSSION: This study is the first to assess the effectiveness and cost-effectiveness/utility of FLS implementation in Germany. Findings of the process evaluation will also shed light on potential barriers to the implementation of FLS in the context of the German healthcare system. Challenges for the study include the successful integration of the outpatient sector as well as the future course of the coronavirus pandemic in 2020 and its influence on the intervention. TRIAL REGISTRATION: German Clinical Trial Register (DRKS) 00022237 , prospectively registered 2020-07-09.

Bone defect reconstruction with a novel biomaterial containing calcium phosphate and aluminum oxide reinforcement.

BACKGROUND: Reconstruction of metaphyseal fractures represents a clinical challenge for orthopedic surgeons. Especially in osteoporotic bone, these fractures are frequently accompanied by osseous substance defects. In order to ensure rapid mobilization of patients, high stability requirements must be met by osteosynthesis. Various bone graft materials have been introduced in the past, such as autologous bone or exogenous bone substitute materials. These are used as bone void fillers or as augmentation techniques to ensure safe fixation of osteosynthesis. New calcium phosphate-based bone void-filling materials could be a promising alternative to autologous bone or to the currently and widely used polymethylmethacrylate (PMMA)-based cement. The aim of this study was to evaluate a novel paste-like bone void filler in vivo and in vitro with regard to biocompatibility and osteoconductivity. METHODS: In addition to in vitro testing of cell compatibility using pre-osteoblasts (MC3T3-E1), 35 Wistar rats were treated in vivo with implantation of various material mixtures based on calcium phosphate and aluminum oxide reinforcement in a metaphyseal drill hole defect. After 4 weeks, an examination by micro-computed tomography (µCT) and histology was performed. RESULTS: The in vitro analysis showed good biocompatibility with a high cell survival of osteoblasts. In the in vivo experiments, a significantly higher bone ingrowth compared to the empty defect was shown by µCT and histological analysis. Here, the group receiving material reinforced with aluminum oxide (Al2O3) showed a bone volume/tissue volume (BV/TV) of 89.19% compared to a BV/TV of 83.14% for the empty defect (p = 0.0013). In the group treated with a polysaccharide matrix, no increase in BV/TV was observed given a mean ratio of 80.14%. Scoring of histological sections did not reveal a significant difference between CaP and CaP that was substituted with Al2O3. CONCLUSION: The results of this study show an encouraging first step towards the development of new pasty, bone void-filling materials. We demonstrated that a new paste-like bone-filling material, based on calcium phosphate granulates and aluminum oxide to provide strength, exhibits good biocompatibility and osteoconductivity. Further biomechanical test in an osteoporotic animal model will have to be performed, to prove feasibility in metaphyseal defects.

Is bone-cement augmentation of screw-anchor fixation systems superior in unstable femoral neck fractures? A biomechanical cadaveric study.

OBJECTIVES: Improved fixation techniques with optional use of bone cements for implant augmentation have been developed to enhance stability and reduce complication rates after osteosynthesis of femoral neck fractures. This biomechanical study aimed to evaluate the effect of cement augmentation on implant anchorage and overall performance of screw-anchor fixation systems in unstable femoral neck fractures. METHODS: Ten pairs of human cadaveric femora were used to create standardized femoral neck fractures (Pauwels type 3 fractures; AO/OTA 31-B2) with comminution and were fixed by means of a rotationally stable screw-anchor (RoSA) system. The specimens were assigned pairwise to two groups and either augmented with PMMA-based cement (Group 1, augmented) or left without such augmentation (Group 2, control). Biomechanical testing, simulating physiological loading at four distinct load levels, was performed over 10.000 cycles for each level with the use of a multidimensional force-transducer system. Data was analysed by means of motion tracking. RESULTS: Stiffness, femoral head rotation, implant migration, femoral neck shortening, and failure load did not differ significantly between the two groups (p ≥ .10). For both groups, the main failure type was dislocation in the frontal plane with consecutive varus collapse). In the cement-augmented specimens, implant migration and femoral neck shortening were significantly dependent on bone mineral density (BMD), with higher values in osteoporotic bones. There was a correlation between failure load and BMD in cement-augmented specimens. CONCLUSION: In screw-anchor fixation of unstable femoral neck fractures, bone-cement augmentation seems to show no additional advantages in regard to stiffness, rotational stability, implant migration, resistance to fracture displacement, femoral neck shortening or failure load.

Training with biofeedback devices improves clinical outcome compared to usual care in patients with unilateral TKA: a systematic review.

PURPOSE: Biofeedback following total knee arthroplasty (TKA) seems to be a feasible approach to improve rehabilitation, outcomes, mobility and reduce pain. This systematic review gives the practicing orthopedic surgeon a summary of what is available and how biofeedback affects clinical outcomes. METHODS: We reviewed the current literature regarding methods, devices and effects of biofeedback in patients who underwent total knee arthroplasty. Embase, Pubmed, Web of Science, and Cochrane Central Register of Controlled Trials were searched from inception to May 2018 for the following keywords: Biofeedback OR Feedback AND Total Knee Arthroplasty OR TKA. Data were extracted according to a predefined setting (see Protocol for systematic review on PROSPEO). Devices used for biofeedback were recorded. Demographics, training methods and effects were also collected. RESULTS: The search resulted in 380 potentially eligible studies from which 11 met all inclusion criteria including 7 randomized controlled trials (RCTs), 3 cohort studies, and 1 cross-sectional study. A total of 416 patients with unilateral TKA were included, with an average of 37.8 patients per study. In patients with TKA, significant improvements in activity scores or pain were reported by 9 of 11 studies. Only two of the studies reported no significant influence of the feedback on the chosen outcome parameters. Devices for biofeedback varied between studies and included the use of a goniometer, force plate, balance board, treadmill, and/or electromyography (EMG). The most common type of feedback was visual followed by audio, with one study mentioning that the audio mode was preferred by the patients as it was easier to handle. Overall, 5 out of 6 different methods demonstrated a potential value for improving mobility and decreasing pain. CONCLUSIONS: This review suggests that biofeedback in early postoperative rehabilitation after TKA is effective in improving gait symmetry, reducing pain and increasing activity level. It should be noted that the great variety of devices used for feedback limits comparisons between studies. LEVEL OF EVIDENCE: IIa.

Impact of vitamin E-blended UHMWPE wear particles on the osseous microenvironment in polyethylene particle-induced osteolysis.

Aseptic loosening mediated by wear particle-induced osteolysis (PIO) remains the major cause of implant loosening in endoprosthetic surgery. The development of new vitamin E (α-tocopherol)-blended ultra-high molecular weight polyethylene (VE-UHMWPE) with increased oxidation resistance and improved mechanical properties has raised hopes. Furthermore, regenerative approaches may be opened, as vitamin E supplementation has shown neuroprotective characteristics mediated via calcitonin gene-related peptide (CGRP), which is known to affect bone remodeling in PIO. Therefore, the present study aimed to further clarify the impact of VE-UHMWPE wear particles on the osseous microenvironment and to identify the potential modulatory pathways involved. Using an established murine calvaria model, mice were subjected to sham operation (SHAM group), or treated with UHMWPE or VE-UHMWPE particles for different experimental durations (7, 14 and 28 days; n=6/group). Morphometric analysis by micro-computed tomography detected significant (p<0.01) and comparable signs of PIO in all particle-treated groups, whereas markers of inflammation [tumor necrosis factor (TNF)-α/tartrate resistant acid phosphatase (TRAP) staining] and bone remodeling [Dickkopf-related protein 1 (DKK-1)/osteoprotegerin (OPG)] were most affected in the early stages following surgery. Taking the present data into account, VE-UHMWPE appears to have a promising biocompatibility and increased ageing resistance. According to the α-CGRP serum levels and immunohistochemistry, the impact of vitamin E on neuropeptidergic signaling and its chance for regenerative approaches requires further investigation.

Hip fracture discrimination from dual-energy X-ray absorptiometry by statistical model registration.

Although the areal Bone Mineral Density (BMD) measurements from dual-energy X-ray absorptiometry (DXA) are able to discriminate between hip fracture cases and controls, the femoral strength is largely determined by the 3D bone structure. In a previous work a statistical model was presented which parameterizes the 3D shape and BMD distribution of the proximal femur. In this study the parameter values resulting from the registration of the model onto DXA images are evaluated for their hip fracture discrimination ability with respect to regular DXA derived areal BMD measurements. The statistical model was constructed from a large database of QCT scans of females with an average age of 67.8 ± 17.0 years. This model was subsequently registered onto the DXA images of a fracture and control group. The fracture group consisted of 175 female patients with an average age of 66.4 ± 9.9 years who suffered a fracture on the contra lateral femur. The control group consisted of 175 female subjects with an average age of 65.3 ± 10.0 years and no fracture history. The discrimination ability of the resulting model parameter values, as well as the areal BMD measurements extracted from the DXA images were evaluated using a logistic regression analysis. The area under the receiver operating curve (AUC) of the combined model parameters and areal BMD values was 0.840 (95% CI 0.799-0.881), whilst using only the areal BMD values resulted in an AUC of 0.802 (95% CI 0.757-0.848). These results indicate that the discrimination ability of the areal BMD values is improved by supplementing them with the model parameter values, which give a more complete representation of the subject specific shape and internal bone distribution. Thus, the presented method potentially allows for an improved hip fracture risk estimation whilst maintaining DXA as the current standard modality.

High-energy phosphate metabolism during two bouts of progressive calf exercise in humans measured by phosphorus-31 magnetic resonance spectroscopy.

According to the literature the steady-state level of phosphocreatine (PCr) has a linear relationship to the workload during muscle exercise intensities below the lactate threshold, whereas this linearity is impaired during exercise intensities above the lactate threshold. The purpose of this study was to investigate the linearity between PCr kinetics and workload during two bouts of isotonic incremental calf exercise with transitions from moderate- to high-intensity as well as from high- to moderate-intensity work rates. Using a whole-body 1.5 T MR scanner and a self-built exercise bench, we performed serial phosphorus-31 magnetic resonance spectroscopy ((31)P-MRS) with a time resolution of 30 s in nine healthy male volunteers. Changes in PCr, inorganic phosphate (Pi) and pH were statistically evaluated in comparison to the baseline. The exercise protocol started with a 4.5 W interval of 6 min followed by two bouts of 1.5 W increments. The workload was increased in 2-min intervals up to 9 W during the first bout and up to 7.5 W during the second bout. The second bout was preceded by a 4.5 W interval of 2 min and followed by a 4.5 W interval of 4 min. PCr hydrolysis achieved a steady state during each increment and was highly linear to the work rate (r (2), -0.796; P <0.001). Pi accumulated during each bout, whereas the pH decreased continuously during the first bout and did not exhibit any substantial decrease during the second bout. The metabolite levels and pH were expressed as the median value and the range. Our study confirms that steady-state PCr levels also have a linear relationship to work intensities above the lactate threshold, while pH changes do not have any impact on PCr degradation. The lack of substantial changes in pH during the second exercise bout indicates that prior high-intensity exercise leads to an activation of oxidative phosphorylation.