Fixation principles in metaphyseal bone—a patent based review

Osteoporotic changes start in cancellous bone due to the underlying pathophysiology. Consequently, the metaphyses are at a higher risk of "osteoporotic” fracture than the diaphysis. Furthermore, implant purchase to fix these fractures is also affected by the poor bone quality. In general, researchers and developers have worked on three different approaches to address the problem of fractures to osteoporotic bone: adapted anchoring techniques, improved load distribution as well as transfer with angular stable screws, and augmentation techniques using bone substitutes. A patent-based review was performed to evaluate which ideas were utilized to improve fixation in osteoporotic, metaphyseal bone, especially in the proximal femur, and to analyze whether the concept had entered clinical use. Anchoring devices that are either extramedullary or intramedullary have a long clinical history. However, demanding surgical techniques and complications, especially in poor quality bone, are justification that such implants and their corresponding surgical techniques need to be improved upon. Expanding elements have been evaluated in the laboratory. The results are promising and the potential of this approach has yet to be fully exploited in the clinics. Internal fixators with angular stable screws open the door for many new anchorage ideas and have great potential for further optimization of load distribution and transfer. Augmentation techniques may improve anchorage in osteoporotic bone. However, the properties of bone substitute materials will need to be modified and improved upon in order to meet the demanding requirements. If we summarise the development process and the clinical use of implants to date, we have to clearly state that more factors than simply biomechanical advantage will determine the clinical success of a new fixation principle or a new implant. Instead, fracture treatment of patients with osteoporosis really needs an interdisciplinary approach

Stabilisierung sub- und pertrochantärer Femurfrakturen mit dem PFNΑ®

Zusammenfassung: Operationsziel: Primär belastungsstabile Osteosynthese per- und subtrochantärer Femurfrakturen mit intramedullärem Kraftträger, besonders auch in osteoporotischem Knochen. Rasche Wiederherstellung der Anatomie und Funktion des verletzten Beins. Indikationen: Sämtliche per- und subtrochantäre Frakturen der AO-Klassifikation 31-A. Kontraindikationen: Offene Wachstumsfugen und ungeeignete Femuranatomie (pathologische Antekurvation bzw. fehlverheilte Schaftfrakturen). Operationstechnik: Wenn möglich geschlossene, bei Bedarf offene Reposition der Faktur auf dem Extensionstisch. Intramedulläre, unaufgebohrte Nagelung und Frakturfixation durch Einbringen einer Spiralklinge über einen Führungsdraht in das Kopf-Halsfragment. Möglichkeit zur dynamischen oder statischen Verriegelung im Femurschaft. Operative Nachsorge: Rasche Mobilisation ab dem ersten postoperativen Tag mit schmerzadaptierter Vollbelastung. Thromboseprophylaxe für 6Wochen mit Fondaparinux, Rivaroxaban oder niedermolekularem Heparin (NMH), alternativ orale Antikoagulation. Ergebnisse: Im Rahmen einer AO-Multizenterstudie an 11 europäischen Kliniken wurden zwischen April 2004 und Juni 2005 313Patienten (Durchschnittsalter 80,6Jahre, 77% Frauen, 23% Männer) mit 315 instabilen pertrochantären Frakturen mittels PFNΑ® ("proximal femoral nail antirotation") operativ stabilisiert [24]. Bei 82% handelte es sich um 31-A2-Frakturen, bei 18% um 31-A3-Frakturen. Die durchschnittliche Operationszeit betrug 56min für die A2-Frakturen und 66min für die A3-Frakturen. Die durchschnittliche Liegedauer im Akutspital betrug 12Tage. Bei 72% der Patienten konnte ein Repositions- und Stabilisierungsergebnis erreicht werden, welches eine unmittelbare postoperative Vollbelastung erlaubte. Insgesamt wurden 165Komplikationen beobachtet, 117 davon waren nicht auf das Implantat zu beziehen. 46 operationsbedingte Komplikationen führten zu 28 ungeplanten Re-Operationen (u.a. 7Femurschaftfrakturen, 4 azetabuläre Penetrationen). 56% der Patienten konnten über ein ganzes Jahr nachkontrolliert werden. Nach einem Jahr waren 89% der Frakturen konsolidiert. Die höchsten Komplikationsraten wiesen Frakturen der Morphologie 31-A2.3 sowie Patienten älter als 90Jahre auf. Mit dem PFNA® wurde damit eine mit den Resultaten anderer intra- und extramedullärer Implantate vergleichbare Anzahl operationsbedingter Komplikationen (14,6%) beschriebe

Recent aspects on outcomes in geriatric fracture patients

As the population ages, the number of fragility fractures is expected to increase dramatically. These injuries are frequently associated with less than satisfactory outcomes. Many of the patients experience adverse events or death, and few regain their pre-injury functional status. Many also lose their independence as a result of their fracture. This manuscript will explore problems and some potential solutions to evaluate the outcomes of geriatric fracture care. Specific, system-wide, and societal concerns will be discussed. Limited suggestions will be made for future steps to improve outcomes assessment

Osteoporosis drug treatment: duration and management after discontinuation. A position statement from the SVGO/ASCO.

Antiosteoporotic drugs are recommended in patients with fragility fractures and in patients considered to be at high fracture risk on the basis of clinical risk factors and/or low bone mineral density. As first-line treatment most patients are started with an antiresorptive treatment, i.e. drugs that inhibit osteoclast development and/or function (bisphosphonates, denosumab, oestrogens or selective oestrogen receptor modulators). In the balance between benefits and risks of antiresorptive treatment, uncertainties remain regarding the optimal treatment duration and the management of patients after drug discontinuation. Based on the available evidence, this position statement will focus on the long-term management of osteoporosis therapy, formulating decision criteria for clinical practice

The furan microsolvation blind challenge for quantum chemical methods: First steps

© 2018 Author(s). Herein we present the results of a blind challenge to quantum chemical methods in the calculation of dimerization preferences in the low temperature gas phase. The target of study was the first step of the microsolvation of furan, 2-methylfuran and 2,5-dimethylfuran with methanol. The dimers were investigated through IR spectroscopy of a supersonic jet expansion. From the measured bands, it was possible to identify a persistent hydrogen bonding OH-O motif in the predominant species. From the presence of another band, which can be attributed to an OH-π interaction, we were able to assert that the energy gap between the two types of dimers should be less than or close to 1 kJ/mol across the series. These values served as a first evaluation ruler for the 12 entries featured in the challenge. A tentative stricter evaluation of the challenge results is also carried out, combining theoretical and experimental results in order to define a smaller error bar. The process was carried out in a double-blind fashion, with both theory and experimental groups unaware of the results on the other side, with the exception of the 2,5-dimethylfuran system which was featured in an earlier publication

Mating plugs in polyandrous giants: Which sex produces them, when, how and why?

10.1371/journal.pone.0040939PLoS ONE77

Orthogeriatric care pathway: a prospective survey of impact on length of stay, mortality and institutionalisation

Introduction: Care pathways for elderly hip fracture patients are increasingly implemented but there has been only limited evaluation of their use. Our objective was to investigate the impact of such a care pathway on the use of healthcare resources and on patients' outcomes. Materials and methods: The prospective survey covered 493 hip fracture patients 65years of age or older that were treated either before "Usual Care=(UC)” or after "Co-Managed-Care=(CMC)” implementation of the care pathway. Primary outcome was length of stay (LoS). Secondary outcomes were 1-year mortality and change in residential status from prefracture baseline to 1-year after surgery. Data were analysed by descriptive and interferential statistics and adjustment for baseline differences amongst the two patient groups was done. Results: Patients in the CMC sample had more preexisting comorbidities (CCI 2.5 versus 2.1). Prior to the fracture, a larger proportion amongst them needed help in ADL (49 versus 26%), and they were more likely to reside in a nursing home (36 versus 29%). Prefracture mobility status was equal in both samples. In the CMC sample LoS was significantly shorter (LoS 8.6 versus 11.3days, p<0.01) and patients were less likely to experience a complication (59 vs 73%, p<0.01) while being in the hospital. There was no significant difference in 1-year mortality or in change of residential status. Conclusions: A care pathway for elderly hip fracture patients allowed decreased LoS without affecting mortality or change of residential status 1year after fracture compared to prefracture baseline

Reinforcing the role of the conventional C-arm - a novel method for simplified distal interlocking

<p>Abstract</p> <p>Background</p> <p>The common practice for insertion of distal locking screws of intramedullary nails is a freehand technique under fluoroscopic control. The process is technically demanding, time-consuming and afflicted to considerable radiation exposure of the patient and the surgical personnel. A new concept is introduced utilizing information from within conventional radiographic images to help accurately guide the surgeon to place the interlocking bolt into the interlocking hole. The newly developed technique was compared to conventional freehand in an operating room (OR) like setting on human cadaveric lower legs in terms of operating time and radiation exposure.</p> <p>Methods</p> <p>The proposed concept (guided freehand), generally based on the freehand gold standard, additionally guides the surgeon by means of visible landmarks projected into the C-arm image. A computer program plans the correct drilling trajectory by processing the lens-shaped hole projections of the interlocking holes from a single image. Holes can be drilled by visually aligning the drill to the planned trajectory. Besides a conventional C-arm, no additional tracking or navigation equipment is required.</p> <p>Ten fresh frozen human below-knee specimens were instrumented with an Expert Tibial Nail (Synthes GmbH, Switzerland). The implants were distally locked by performing the newly proposed technique as well as the conventional freehand technique on each specimen. An orthopedic resident surgeon inserted four distal screws per procedure. Operating time, number of images and radiation time were recorded and statistically compared between interlocking techniques using non-parametric tests.</p> <p>Results</p> <p>A 58% reduction in number of taken images per screw was found for the guided freehand technique (7.4 ± 3.4) (mean ± SD) compared to the freehand technique (17.6 ± 10.3) (<it>p </it>< 0.001). Total radiation time (all 4 screws) was 55% lower for the guided freehand technique compared to conventional freehand (<it>p </it>= 0.001). Operating time per screw (from first shot to screw tightened) was on average 22% reduced by guided freehand (<it>p </it>= 0.018).</p> <p>Conclusions</p> <p>In an experimental setting, the newly developed guided freehand technique for distal interlocking has proven to markedly reduce radiation exposure when compared to the conventional freehand technique. The method utilizes established clinical workflows and does not require cost intensive add-on devices or extensive training. The underlying principle carries potential to assist implant positioning in numerous other applications within orthopedics and trauma from screw insertions to placement of plates, nails or prostheses.</p

The first microsolvation step for furans : new experiments and benchmarking strategies

The site-specific first microsolvation step of furan and some of its derivatives with methanol is explored to benchmark the ability of quantum-chemical methods to describe the structure, energetics, and vibrational spectrum at low temperature. Infrared and microwave spectra in supersonic jet expansions are used to quantify the docking preference and some relevant quantum states of the model complexes. Microwave spectroscopy strictly rules out in-plane docking of methanol as opposed to the top coordination of the aromatic ring. Contrasting comparison strategies, which emphasize either the experimental or the theoretical input, are explored. Within the harmonic approximation, only a few composite computational approaches are able to achieve a satisfactory performance. Deuteration experiments suggest that the harmonic treatment itself is largely justified for the zero-point energy, likely and by design due to the systematic cancellation of important anharmonic contributions between the docking variants. Therefore, discrepancies between experiment and theory for the isomer abundance are tentatively assigned to electronic structure deficiencies, but uncertainties remain on the nuclear dynamics side. Attempts to include anharmonic contributions indicate that for systems of this size, a uniform treatment of anharmonicity with systematically improved performance is not yet in sight