Initial Fracture Site Research Articles

Comparison of the cost-effectiveness of sequential treatment with abaloparatide in US men and women at very high risk of fractures

BackgroundOsteoporotic-related fractures represent an increasing burden to patients, health care systems and society.AimsThis study estimated cost-effectiveness of sequential treatment with abaloparatide (ABL) followed by alendronate (ALN) compared to relevant alternative strategies in US men and women aged 50 to 80 years at very high fracture risk (bone mineral density T-score ≤ − 2.5 and a recent fracture).MethodsA lifetime Markov-based microsimulation model was used to estimate healthcare costs and quality-adjusted life years (QALYs). Comparators were sequential treatment with unbranded teriparatide (TPTD)/ALN, generic ALN monotherapy, and no treatment. Analyses were conducted based on initial fracture site (hip, vertebral, or any fracture) and treatment efficacy data (derived from clinical trials or a recent network meta-analysis).ResultsFrom all analyses completed, sequential ABL/ALN demonstrated more QALYs for lower healthcare costs versus unbranded TPTD/ALN. No treatment was dominated (higher costs for less QALYs) versus ALN monotherapy. Sequential ABL/ALN resulted in favorable cost-effectiveness (at US threshold of $150,000/QALY) versus generic ALN monotherapy in men aged ≥ 50 years with any fracture type, women aged ≥ 65 years with any fracture type, and women aged ≥ 55 years having a hip or vertebral fracture.DiscussionSimilar cost-effectiveness of sequential ABL/ALN versus unbranded TPTD/ALN, ALN monotherapy, and no treatment was observed in both US men and women at very high fracture risk, with a moderate improvement in cost-effectiveness in men versus women and in patients with a hip or vertebral fracture.ConclusionsSequential therapy with ABL/ALN was cost-effective in US men and women at very high risk of fractures.

Subsequent Forearm Fractures Following Initial Surgical Fixation.

Forearm fractures are a common pediatric injury. Currently, there is no consensus on treatment for fractures that recur following initial surgical fixation. The objective of this study was to investigate the subsequent fracture rate and patterns and describe the treatment of these forearm fractures. We retrospectively identified patients who underwent surgical treatment for an initial forearm fracture at our institution between 2011 and 2019. Patients were included if they sustained a diaphyseal or metadiaphyseal forearm fracture that was initially treated surgically with a plate and screw construct (plate) or elastic stable intramedullary nail (ESIN), and if they subsequently sustained another fracture that was treated at our institution. A total of 349 forearm fractures were treated surgically with ESIN or a plate fixation. Of these, 24 sustained another fracture, yielding a subsequent fracture rate of 10.9% for the plate cohort and 5.1% for the ESIN cohort ( P =0.056). The majority of plate refractures (90%) occurred at the proximal or distal plate edge, while 79% of the fractures treated previously with ESINs occurred at the initial fracture site ( P <0.001). Ninety percent of plate refractures required revision surgery, with 50% underwent plate removal and conversion to ESIN, and 40% underwent revision plating. Within the ESIN cohort, 64% were treated nonsurgically, 21% underwent revision ESINs, and 14% underwent revision plating. Tourniquet time for revision surgeries were shorter for the ESIN cohort (46 vs. 92min; P =0.012). In both cohorts, all revision surgeries had no complications and healed with evidence of radiographic union. However, 9 patients (37.5%) underwent implant removal (3 plates and 6 ESINs) after subsequent fracture healing. This is the first study to characterize subsequent forearm fractures following both ESIN and plate fixation and to describe and compare treatment options. Consistent with the literature, refractures following surgical fixation of pediatric forearm fractures may occur at a rate ranging from 5% to 11%. ESINs are both less invasive at the time of initial surgery and can often be treated nonoperatively if there is a subsequent fracture, while plate refractures are more likely to be treated with a second surgery and have a longer average surgery time. Level IV-retrospective case series.

Fracture Interference and Refracturing of Horizontal Wells

Due to fracture interference, not all perforations can be fractured, resulting in 20% of fractures contributing to 80% of the total production. The extraction of oil and gas also reduces production, necessitating refracturing. In this study, the finite element method was used to simulate multiple fractures fracturing simultaneously and the stress field distribution was then extracted and applied to a new geological model. This paper explains the effect of stress around the horizontal wellbore on new fractures during the refracturing of old wells using a temporary plugging technique. The results show that initial breaking pressures are the same, but as fractures extend, inter-fracture interference increases, resulting in different fracture extension pressures and widths. The fracturing fluid is filtered into the reservoir matrix after fracturing, reducing formation stress. Compared with fracturing at the initial fracture site, reperforating fracturing has a lower fracture extension pressure and a longer fracture length. According to this study, hydraulic fractures have a 15 m effective influence radius on the external formation. Stress relief is beneficial for fracture initiation prior to refracturing. Reperforating and fracturing, in combination with temporary plugging technology, can assist in increasing the effective stimulated reservoir volume and achieving high and stable production.

Load to failure of three different monolithic zirconia inlay- retained fixed dental prosthesis designs with three surface treatments

Objective: The purpose of the study was to evaluate the effect of different preparation designs and different surface treatments on the fracture resistance of monolithic zirconia inlay-retained fixed dental prosthesis [IRFDP]. Material and methods: Forty-five translucent zirconia IRFDPs were divided into three groups according to preparation designs (n = 15); group I: proximal box, group II: inlay-box and group III: butterfly wing (modified inlay). Each group was further subdivided into three subgroups according to the surface treatments utilized (n = 5); sandblasting, tribochemical silica coating (Cojet system) and erbium, chromium: Yttrium, scandium, gallium, garnet (Er, Cr: YSGG) laser irradiation. All zirconia IRFDPs were cemented to their respective resin models using selfadhesive resin cement. All cemented IRFDPs were subjected to fracture resistance test using universal testing machine. The initial fracture site was determined by using a stereomicroscope (x6.7magnification). Two-way analysis of variance (ANOVA) was used to evaluate the effect of different designs, different surface treatments and their interaction on the mean fracture resistance. Bonferroni’s post-hoc test was used when ANOVA is significant (P ? 0.05). Results: Butterfly wings design showed the highest fracture resistance values followed by inlay and box designs respectively (P ? 0.05). Sandblasting and Cojet showed significantly the highest mean fracture resistance values than Laser with no significance difference between them. Conclusion: The butterfly wing design increased the fracture resistance of the zirconia IRFDPs. Sandblasting and tribochemical silica coating of zirconia surfaces had a greater effect than Er, Cr: YSGG laser to gain higher fracture resistance of zirconia IRRDPs.KEYWORDSInlay-retained FDPs; Monolithic zirconia; Preparation designs; Surface treatments; fracture resistance.

Numerical Investigation of the Fracture Properties of Pre-Cracked Monocrystalline/Polycrystalline Graphene Sheets.

The fracture properties of pre-cracked monocrystalline/polycrystalline graphene were investigated via a finite element method based on molecular structure mechanics, and the mode I critical stress intensity factor (SIF) was calculated by the Griffith criterion in classical fracture mechanics. For monocrystalline graphene, the size effects of mode I fracture toughness and the influence of crack width on the mode I fracture toughness were investigated. Moreover, it was found that the ratio of crack length to graphene width has a significant influence on the mode I fracture toughness. For polycrystalline graphene, the strain energy per unit area at different positions was calculated, and the initial fracture site (near grain boundary) was deduced from the variation tendency of the strain energy per unit area. In addition, the effects of misorientation angle of the grain boundary (GB) and the distance between the crack tip and GB on mode I fracture toughness were also analyzed. It was found that the mode I fracture toughness increases with increasing misorientation angle. As the distance between the crack tip and GB increases, the mode I fracture toughness first decreases and then tends to stabilize.

Risk of subsequent fracture after prior fracture among older women

SummaryAmong 377,561 female Medicare beneficiaries who sustained a fracture, 10% had another fracture within 1 year, 18% within 2 years, and 31% within 5 years. Timely management to reduce risk of subsequent fracture is warranted following all nontraumatic fractures, including nonhip nonvertebral fractures, in older women.IntroductionPrior fracture is a strong predictor of subsequent fracture; however, postfracture treatment rates are low. Quantifying imminent (12–24 month) risk of subsequent fracture in older women may clarify the need for early postfracture management.MethodsThis retrospective cohort study used Medicare administrative claims data. Women ≥ 65 years who sustained a clinical fracture (clinical vertebral and nonvertebral fracture; index date) and were continuously enrolled for 1-year pre-index and ≥ 1-year (≥ 2 or ≥ 5 years for outcomes at those time points) post-index were included. Cumulative incidence of subsequent fracture was calculated from 30 days post-index to 1, 2, and 5 years post-index. For appendicular fractures, only those requiring hospitalization or surgical repair were counted. Death was considered a competing risk.ResultsAmong 377,561 women (210,621 and 10,969 for 2- and 5-year outcomes), cumulative risk of subsequent fracture was 10%, 18%, and 31% at 1, 2, and 5 years post-index, respectively. Among women age 65–74 years with initial clinical vertebral, hip, pelvis, femur, or clavicle fractures and all women ≥ 75 years regardless of initial fracture site (except ankle and tibia/fibula), 7–14% fractured again within 1 year depending on initial fracture site; risk rose to 15–26% within 2 years and 28–42% within 5 years. Risk of subsequent hip fracture exceeded 3% within 5 years in all women studied, except those < 75 years with an initial tibia/fibula or ankle fracture.ConclusionsWe observed a high and early risk of subsequent fracture following a broad array of initial fractures. Timely management with consideration of pharmacotherapy is warranted in older women following all fracture types evaluated.

Evaluation of osteoporotic trochanteric fractures treated with cement-augmented dynamic hip screw

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; Dynamic hip screw (DHS) has been the standard treatment for stable trochanteric fracture patterns. However, primary stabilization with dynamic/sliding hip screw is not always successful, especially in osteoporotic fractures. Internal fixation in such a situation may achieve a satisfactory initial fracture site reduction, but late fracture collapse into varus during weight bearing, can lead to a high failure rate. Since 1975, polymethylmethacrylate (PMMA) cement-augmented DHS have been used as a solution in unstable ITFs by adding an anchoring ability to the lag screw.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; A series of 33 osteoporotic intertrochanteric fractures were operated with cement augmented dynamic hip screw. One patient lost to follow up. All patients were then allowed partial weight bearing walker aided ambulation under the guidance of physiotherapist on the second or third postoperative day. The patients were followed radio logically and clinically at regular intervals (1st month, than at 3rd month and then at 6th month interval after surgery). Results were graded as excellent (score &amp;gt;31), good (score 24-31), fair (score 16-23), and poor (score &amp;lt;16). Clinical result was given according to Salvati and Wilson scoring.&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; Total 33 patients were taken for the study they were followed for minimum 6 months and at 6 months the clinical outcome was rated as per the Salvati and Wilson scoring system. One patient lost to follow-up. Final clinical results as evaluated by Salvati and Wilson scoring were; excellent in 24 cases (75%), good in 7 cases (21.88%), fair in 1 case (3.12%) and poor in 0 cases (0%). There were no non-union, AVN, implant failure and screw cut-out in our study.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; The surgical management of intertrochanteric fractures with PMMA augmented DHS provide a stable fixation with moderate pain free early mobilisation and better outcome in osteoporotic patients without the complications of superior screw cut-out, sliding collapse, and with the appropriate placement of bone cement along with proper amount (4-5 ml) of cement we can also reduce the cement related complications such as delayed healing, nonunion, heat necrosis and avascular necrosis.&lt;/p&gt;

Repeatability of digital image correlation for measurement of surface strains in composite long bones

Digital image correlation (DIC) can measure full-field surface strains during mechanical testing of hard and soft tissues. When compared to traditional methods, such as strain gauges, DIC offers larger validation data (∼50,000 points) for, e.g., finite element models. Our main aim was to evaluate the repeatability of surface strain measurements with DIC during compressive testing of composite femurs mimicking human bones. We also studied the similarity of the composite femur samples using CT. Composite femurs were chosen as test material to minimize the uncertainties associated with the use of cadaveric tissues and to understand the variability of the DIC measurement itself. Six medium-sized fourth generation composite human proximal femora (Sawbones) were CT imaged and mechanically tested in stance configuration. The force–displacement curves were recorded and the 3D surface strains were measured with DIC on the anterior surface of the femurs. Five femurs fractured at the neck–trochanter junction and one at the site below the minor trochanter. CT image of this bone showed an air cavity at the initial fracture site. All femurs fractured through a sudden brittle crack. The fracture force for the composite bones was 5751±650N (mean±SD). The maximum von Mises strain during the fractures was 2.4±0.8%. Noise in one experiment was 5–30µε. When applied loads were equalized the variation in strains between the bones was 20–25%, and when the maximum strains were equalized, variation in the other regions was 5–10%. DIC showed that the ability of nominally identical composite bones to bear high strains and loads before fracturing may vary between the samples.

Intrinsic Strength and Failure Behaviors of Graphene Grain Boundaries

As one-dimension line defects, grain boundaries (GBs) can affect many intrinsic properties of graphene. In this paper, the mechanical properties of 20 representative graphene grain boundaries were studied using density functional theory and molecular dynamics. With different arrangements of the pentagonal and heptagonal rings, the grain boundary may remain flat or become inflected up to 72°. For the flat GBs, the intrinsic tensile strength decreases linearly with the formation energy with a maximum value of 93 GPa, close to that of a perfect graphene. The intrinsic tensile strength of the inflected GBs is found to generally decrease with increasing inflection angle. Stone-Wales transformation is identified as the major failure mechanism of graphene GBs at high temperatures, whereas the initial fracture site can be either on the boundary line or inside the domain. These theoretical results constitute a useful picture of the grain boundary effect on the mechanical properties of polycrystalline graphene.

骨破壊時のアコースティック・エミッション（音響放射）の測定 骨折部位，時期，範囲の推定に関する基礎的研究

It is known that a peculiar sound is produced when metallic or plastic material is cracked. This sound, caused by elastic waves generated by the release of strain energy stored in a solid during its plastic deformation, is called acoustic emission. Since acoustic emission is composed of elastic waves, an initial fracture point can be determined by measurement of the lag in elastic wave arrival time. Also the amount of energy released at the time of cracking of a solid object can be calculated by application of the destruction theory of Griffith which specifies the amount of energy released as the function of cracking area.Thus precise quantitative analysis of the cracking phenomenon of solid material is possible by means of acoustic emission measurement. However, acoustic emission in biological materials has so far been little studied. Perceiving the usefulness of acoustic emission in biological materials, the author attempted to examine the mechanism of bone fracture by detecting the initial point of fracture and calculating the amount of energy released. The experimental material consisted of a humerus, radius, femur, and tibia from a 3-year-old mongrel dog weighting 16 kg, and theedentulous mandible from an Indo-European male of estimated 60 years age. The materials were subjected to a three-point bending test. The acoustic emission in this test was picked up by acoustic emission sensors (s 9220, Physical Acoustic Co.), its amplitude magnified with a preamplifier (122 A, Physical Acoustic Co.), and the data analyzed with an acoustic emission analyzer (LOCAN Jr, Physical Acoustic Co.).The initial fracture site was ascertained from the lag in acoustic emission arrival time, frequency of acoustic emission, maximum amplitude of acoustic emission, and distribution of maximum amplitude. The amount and ratio of energy release were also calculated.The following conclusions were drawn from this study:1. It is possible to determine the initial fracture point and to follow the exact phases of the fracture process.2. Prediction of the fracture time based on increased frequency of acoustic emission seemed difficult because the total frequency of acoustic emission varied structurally with a load-strain increase.3. By calculating the ratio of energy release it seemed possible to predict the extent of bone fracture under d given load.

Hip Fracture Recurrence

In a large population-based study of hip fracture recurrence in Rochester, Minnesota, the overall risk of any recurrence, ipsilateral or contralateral, was estimated to be 29% by 20 years after initial fracture, 1.6 times greater than expected. The risk of recurrence was greater in patients who had initial fractures associated with moderate trauma and in younger patients. The increased risk among women compared to men was eliminated when the degree of trauma was considered. Ipsilateral recurrence at the same fracture site was less frequent than expected, and the overall increased risk was primarily due to contralateral fractures at the initial fracture site (cervical or intertrochanteric). There was no difference in recurrence rate with respect to site or side of the initial fracture, and no concentration of recurrences was observed for any particular time interval following the first hip fracture.