A Thesis submitted to The University of Arizona College of Medicine - Phoenix in partial fulfillment of the requirements for the Degree of Doctor of Medicine. / The (Surgical Implant Generation Network) SIGN Intramedullary (IM) nail is designed to fix long bone fractures without using a costly C‐arm imaging device. It is distributed for free to countries in need, allowing for elevation of care from the standard, lengthy traction treatment in those countries to clinically superior IM nailing. This paper compares the clinical outcomes of the SIGN IM nail to those of the IM nails used in developed countries with use of a C‐arm. The terms “Surgical Implant Generation Network” and “union” were searched in four databases. Primary studies of SIGN IM nails were included and their outcomes, including union rate, time to union, and complications, were recorded and compared to historical data of IM nails used in developed countries. Overall, there is a similar union rate in bones fixed with SIGN IM nails (94.6%) versus bones fixed with IM nails in developed countries (92.3%) (p = 0.009, OR = 1.67), while some bone types (tibia and femur) demonstrated a lower union rate when individually stratified (p = 0.008, OR = 0.26 and p = 0.002 and OR = 0.15, respectively). Mean time to union for all bone types combined showed no significant difference between SIGN IM nails and IM nails used in developed countries (p = 0.26). Complications rates were similar between SIGN IM nails and IM nails used in developed countries. It is possible for the SIGN IM nail to be used to fix long bone fractures in developing countries with outcomes comparable to the IM nail used in developed countries.

Objectives The Radiographic Union Score for Tibia (RUST) scoring system has been validated in multiple studies assessing the healing of tibial fractures. Our objective was to assess the inter and intraobserver reliability for the RUST in diaphyseal femoral fractures treated with intramedullary (IM) nailing. Patients and Methods A total of 60 sets of anteroposterior (AP) and lateral radiographs of diaphyseal femoral fractures treated by reamed IM nailing were randomly selected from a prospectively collected database. The 60 sets of radiographs were then scored by three reviewers using the RUST system. Interobserver reliability was measured at initial scoring. The 60 sets of radiographs were scored again by the three reviewers to calculate the intraobserver reliability. Results The RUST scores ranged from 4 to 12 with a mean score of 11.3 ± 1.3. The interobserver intraclass correlation coefficient (ICC) was 0.87 (95% CI, 0.81-0.92) and the intraobserver ICC was 0.91 (95% CI, 0.88-0.94), which indicated excellent agreement. Conclusion This study demonstrated that the RUST system can be used reliably in the assessment of healing in diaphyseal femur fractures treated by reamed intramedullary nailing, with excellent interobserver and intraobserver reliability.

Η παρούσα διδακτορική διατριβή περιγράφει το σχεδιασμό και την ανάπτυξη ενός εκπτυσσόμενου Ενδομυελικού Ήλου Επιμήκυνσης των Μακρών Οστών των Κάτω Άκρων. Η επιμήκυνση των κάτω άκρων είναι μία χειρουργική διαδικασία βαθμιαίας επιμήκυνσης των μακρών οστών των κάτω άκρων και των μαλακών μορίων που τα περιβάλουν. Γενικά, η επιμήκυνση των κάτω άκρων στοχεύει στην εξίσωση των σκελών ή αύξηση του μήκους των οστών και στα δύο άκρα. Η τεχνική αύξησης του μήκους των οστών των κάτω άκρων επινοήθηκε από τις αρχές του περασμένου αιώνα [1] και έχει καταξιωθεί στη μοντέρνα χειρουργική από τις αρχές του 1960, λόγω της ενασχόλησης του G.A.Ilizarov. Ο επιστήμονας και χειρουργός G.A.Ilizarov αφιέρωσε όλη τη θεωρητική και πρακτική του έρευνα [2] στη βελτίωση της διαδικασίας επιμήκυνσης των οστών και την ανάπτυξη εξωτερικής συσκευής σταθεροποίησης που φέρει το όνομα του. Η μέθοδος αυτή καθώς και η συσκευή Ilizarov χρησιμοποιήθηκαν πάρα πολύ για να διορθώσουν τόσο βλάβες όσο και παραμορφώσεις των κάτω άκρων. Η ευελιξία αυτής της συσκευής την κάνει ένα εξαιρετικό εργαλείο το οποίο μπορεί να χρησιμοποιηθεί για τη διόρθωση διαφόρων βλαβών όπως π.χ. σταθεροποίηση συνθέτων καταγμάτων, στροφικές διορθώσεις, διορθώσεις οστών με διαφορές μήκους. Τόσο όμως η συσκευή του Ilizarov όσο και οι υπόλοιποι μονόπακτοι εξωτερικοί σταθεροποιητές που παρουσιάσθηκαν αργότερα παρουσιάζουν μειονεκτήματα [3] όπως είναι π.χ. οι σύνθετες χειρουργικές διαδικασίες, οι συνδέσεις και οι βελόνες που διαπερνούν το δέρμα και που οδηγούν σε μολύνσεις, η μειωμένη δυνατότητα φόρτισης και η ταλαιπωρία λόγω του μεγέθους του σταθεροποιητή ειδικά στις περιπτώσεις εκείνες που η ευελιξία του σταθεροποιητή δεν είναι απαραίτητη. Πολλοί ασθενείς που χρειάζονται μία διόρθωση του μήκους ενός άκρου χωρίς άλλες παραμορφώσεις θα μπορούσαν να βοηθηθούν και από μία συσκευή μικρότερης ευελιξίας χωρίς τα μειονεκτήματα των εξωτερικών μονόπακτων σταθεροποιητών. / The technique to increase the length of the long bones is the subject of research for the orthopedic surgeons for many years. The technique is used for the treatment of a limb shortening due to malformation or to a deficit for other reasons e.g. the fracture of a long bone after a car accident, osteomyelitis, or malignancy. The procedure to increase the length of a bone is difficult and may become quite hazardous for the soft tissues surrounding the area. The two parts of the bone are stabilized to eliminate the possibility of relative torsion and bending. Then they align axially with respect to each other and move with a constant rate of elongation of 1mm per day. The elongation is usually achieved by 4 steps of 0,25mm every 6 hours. The application of internal distraction osteogenesis using shape memory alloys has all the advantages of internal osteosynthesis. The only part of these mechanisms that is found externally is the activation mechanism that is connected by the necessary cables of activation with the interior of the bone where the internal distraction device is placed. The basic problem of all designs is the high constructional complexity of activation and control of shift of the two parts of the bone, something that makes this systems non user friendly and with continuous fractures and blockings of the elements of the mechanisms. In the present work, all the advantages of the mechanism of internal distraction osteogenesis are combined with the fundamental advantage; the simplicity of manufacture of the mechanism and the simplicity of operation via the restriction of the moving elements.

This diploma thesis is focused on designing innovation of manufacturing calcaneal nail C-NAIL. The thesis contains analysis of technological processes of current manufacturing. There is also information about materials which are used for the manufactory. Finally, the thesis contains a designed technological process for manufacturing calcaneal nail C-NAIL.

The presented Master’s Thesis aims at determining stress and strain analysis of femur with fracture fixed by intramedullary nail and cerclage cable. The one of the goals of this work was create computational model which will be able simulate problem. Computational model consist of model of femur , it’s geometry was created on basis of CT data, than there was created model of intramedullary nail and cerclage cable on a basis of real objects. In this work was created simply model of femur with the same material features and characteristic proportions as analyzed model of femur. On this model was investigated direct impact of cerclage cables on deformation, respectively displacement in a surroundings of femoral fracture. On a final model were applied the real loads conditions. Preload in a cerclage cable was simulated by cooling down to a temperature from analytical calculation. Concluding analysis was powered by Finite Element Method (FEM) applied in system ANSYS Workbench 14.5 . Due to a results of analysis, we could say that using cerclage cables in combination with intramedullary nail is an effective way for healing femoral shaft fractures.

The presented Master Thesis is focused on the structural analysis of the proximal femur on which the Proximal Femoral Nail (PFN) and Proximal Femoral Tele-Screw (PFT) systems are applied. These systems are used for a treatment of the intertrochanteric and femoral neck fractures. However, in some cases a loss of stability of the systems may be expected. The presented thesis describes a development of numerical models in which stress distribution of implants and strain distribution of bone tissue are compared. Numerical models were created from real objects. The model of femur geometry was created by using the Computed Tomography (CT). Boundary conditions of the model were estimated from the force equilibrium of the lower limb. All numerical models were processed in the commercial package ANSYS Workbench v15.0. It is shown that the hip screws of the PFN system result in lower equivalent stresses than the screws of the PFT system. Maximal strains of the bone tissue, when using the PFN system, are situated near the fracture, close the hip screw thread. For the PFT system, the maximal strains are only near the area of fracture.

This master's thesis focuses on the utilization of an artificially created weak magnetic field for navigation in 3D space. The theoretical part of this work deals with the general properties of the magnetic field and with its description. The next section of the theoretical part contains an overview of measuring principles for magnetic field measurements. Based on various types of measuring principles, the thesis elaborates on commercially available miniature sensors for magnetic field measurement with a measuring range up to 10 mT. The work focuses mainly on the magnetoresistive principle and fluxgate sensors. Furthermore, the theoretical part contains descriptions of methods for modeling the magnetic field of simple permanent magnets and various magnet assemblies. Lastly, the theoretical part involves a patent search of devices used for locating magnets that are installed in an intramedullary nail, which is used in intramedullary stabilization used on fractures of human bones. By locating the magnet in the nail, it is possible to precisely determine the position of the mounting holes. The practical part of the thesis deals with the analysis of magnetic field behavior in the vicinity of various magnetic assemblies, which were modeled in COMSOL Multiphysics using the finite element method. The models were created with the aim of analysing the behaviour of the magnetic field in the vicinity of the magnets and at the same time to find possible analytical functions that could be used to determine the position of the magnet in space relative to the probe. The result of this work is an analysis of various assemblies, which contains graphs of different dependencies and prescription of polynomial functions that approximate these dependencies. Another part of the thesis is the design of a probe that serves to locate the magnetic target. The work describes two possible methods of localization. For the differential method, a user interface in LabVIEW was created. The probe based on this method is fully capable of locating the magnet in the 2D plane. The state space search method is described only in theory.