Osteoporosis, associated with reduced bone mineral density and structural degeneration, greatly increases the risk of fragility fracture. Magnetic resonance imaging (MRI) has been applied to central skeletal sites including the proximal femur due to its non-ionizing radiation. A major challenge of volumetric bone imaging of the hip is the selection of regions of interest (ROIs) for computation of regional bone measurements. To address this issue, an MRI-based active shape model (ASM) of the human proximal femur is applied to automatically generate ROIs. The challenge in developing the ASM for a complex three-dimensional (3-D) shape lies in determining a large number of anatomically consistent landmarks for a set of training shapes. This thesis proposes a new method of generating the proximal femur ASM, where two types of landmarks, namely fiducial and secondary landmarks, are used. The method consists of—(1) segmentation of the proximal femur bone volume, (2) smoothing the bone surface, (3) drawing fiducial landmark lines on training shapes, (4) drawing secondary landmarks on a reference shape, (5) landmark mesh generation on the reference shape using both fiducial and secondary landmarks, (6) generation of secondary landmarks on other training shapes using the correspondence of fiducial landmarks and an elastic deformation of the landmark mesh, (7) computation of the active shape model. A proximal femur ASM has been developed using hip MR scans of 45 post-menopausal women. The results of secondary landmark generation were visually satisfactory, and no topology violation or notable geometric distortion artifacts were observed. Performance of the method was examined in terms of shape representation errors in a leave-one-out test. The mean and standard deviation of leave-one-out shape representation errors were 0.34mm and 0.09mm respectively. The experimental results suggest that the framework of fiducial and secondary landmarks allows reliable computation of statistical shape models for complex 3-D anatomic structures.

The mechanical behavior of any bone depends upon structural and material properties. Therefore, whole bone, cross-sectional geometric and bone mineral data need to be integrated in studies of bone growth and aging. This dissertation examines femoral growth and aging in the prehistoric Grasshopper Pueblo population of Arizona (A.D. 1275 to 1400). The techniques include osteometrics, computed tomography and photon absorptiometry. Human osteological collections obtained from archaeological sites are useful for studies of bone physiology and mechanics. Even though the subjects are no longer living, non-invasive techniques must often be used because the skeletal collections are data bases for many researchers. This apparently limiting attribute of the sample used in the present study forced the application of computed tomography for analysis of cross-sectional geometry. As the availability of computed tomography to research increases, it will become the method of choice because digital images are well-suited to automated analysis and CT can also provide density data. Variability related to side, age and sex is explored. Additionally, (1) structural properties increase much more than material properties in growth, (2) the morphology of the proximal femoral diaphysis depends more upon the angle of antetorsion than the cervicodiaphyseal angle, (3) there is evidence suggestive of structural compensation for loss of bone mineral in aging, (4) osteoporosis is found not to protect the femoral compartment of the knee joint from osteoarthrosis, (5) the onset of bone loss in females seems to have been early by modern standards, although the rates of loss were similar, and (6) differential bone loss within the femur due to the amount of bone present at maturity and not different rates of loss.

Μελέτη της ανάστροφης ενδομυελικής ήλωσης στα κατάγματα του περιφερικού μηριαίου, στα υπερκονδύλια περιπροθετικά κατάγματα του μηριαίου και η εξέλιξη της χειρουργικής τεχνικής. Υλικό-Μέθοδος: Μελετήθηκαν 57 κατάγματα του περιφερικού μηριαίου σε 53 ασθενείς, 10 περιπροθετικά κατάγματα σε 9 ασθενείς ενώ η εξελιγμένη μορφή της τεχνικής εφαρμόστηκε σε 9 ασθενείς κατά την περίοδο 1997-2004. Αποτελέσματα: Στην ομάδα των καταγμάτων του περιφερικού μηριαίου υπήρξαν 2 ψευδαρθρώσεις και 3 επιπολής μικροβιακές φλεγμονές. Στα περιπροθετικά κατάγματα το ποσοστό πώρωσης ανήλθε στο 100%, ενώ με την αρθροσκοπικά υποβοηθούμενη τεχνική μειώθηκε σημαντικά η περιεγχειρητική θνησιμότητα. Συμπεράσματα: Η ανάστροφη ενδομυελική ήλωση αποτελεί μία αξιόπιστη τεχνική με υψηλό ποσοστό πώρωσης και μικρή συχνότητα επιπλοκών. Με την αρθροσκοπικά υποβοηθούμενη τεχνική μειώνεται σημαντικά η περιεγχειρητική θνησιμότητα. / To evaluate the retrograde intramedullary nailing in distal femoral fractures, in supracondylar periprosthetic fractures and to present the arthroscopically assisted technique. Material-Method: Between 1997 and 2004 we have treated 57 distal femoral fractures in 53 patients, 10 supracondylar periprosthetic fractures in 9 patients and we have applied the arthroscopically assisted technique in 9 patients. Results: In the distal femoral fracture group there were 2 nonunions and 3 superficial infections. In the supracondylar periprosthetic fractures the union rate was 100%. With the arthroscopically assisted technique the postoperative morbidity was reduced significantly. Conclusions: Retrograde intramedullary nailing is a reliable technique to treat distal femoral fractures. It is accompanied by a high union rate and low complication rate. The arthroscopically assisted technique has also reduced significantly the postoperative morbidity.

Delayed or impaired bone healing occurs in 5-10% of all fractures, yet cost effective solutions to enhance the healing process are limited. Lithium, a current treatment for bipolar disorder, is not clinically indicated for use in fracture management, but has been reported to positively influence bone biology. The objective of this study was to identify lithium administration parameters that maximize bone healing in a preclinical, rodent femur fracture model. Using a three factor, two level, design of experiments (DOE) approach, bone healing was assessed through mechanical testing and μCT-image analysis. Significant improvements in healing were found at a low dose, later onset, longer duration treatment combination, with onset identified as the most influential parameter. The positive results from this DOE screening focuses the optimization phase towards further investigation of the onset component of treatment, and forms a crucial foundation for future studies evaluating the role of lithium in fracture healing.

Delayed or impaired bone healing occurs in 5-10% of all fractures, yet cost effective solutions to enhance the healing process are limited. Lithium, a current treatment for bipolar disorder, is not clinically indicated for use in fracture management, but has been reported to positively influence bone biology. The objective of this study was to identify lithium administration parameters that maximize bone healing in a preclinical, rodent femur fracture model. Using a three factor, two level, design of experiments (DOE) approach, bone healing was assessed through mechanical testing and μCT-image analysis. Significant improvements in healing were found at a low dose, later onset, longer duration treatment combination, with onset identified as the most influential parameter. The positive results from this DOE screening focuses the optimization phase towards further investigation of the onset component of treatment, and forms a crucial foundation for future studies evaluating the role of lithium in fracture healing.

Extended periods of mechanical unloading are known to be detrimental to bone health. Astronauts who spend months in microgravity aboard the International Space Station (ISS) are at particular risk. It is anticipated that NASA will not drastically increase the size of the astronaut corps, and this will mean increased likelihood of repeat missions for more astronauts. Thus, it is important to better understand the effects that prolonged, multiple bouts of unloading have on bone. This study utilized the hindlimb unloaded (HU) rat model to examine bone loss and recovery for single and double unloading bouts. Adult male Sprague-Dawley rats (6 months old) were randomized into the following groups: baseline (sacrificed at 6 months), 1HU7 (unloaded for 1 month, weight-bearing recovery for 3 months), 2HU10 (unloaded for 1 month, recovered for 2 months, unloaded for another month, and then recovered 2 months), 1HU10 (normal cage activity until 1 month HU ending at month 10, 2 month recovery followed), and aging controls (remained ambulatory throughout experiment). Every month (28 days), animals were terminated and the left femurs were excised, resulting in n=15 per group for each time point. Mineral and geometric properties were measured using peripheral quantitative computed tomography (pQCT) at the distal femur metaphysis, and quasi-static reduced platen compression (RPC) was used to estimate the mechanical properties of cancellous bone. Strength indices based on pQCT parameters were calculated as predictors of mechanical properties. Bone mass properties decreased due to HU and recovered within 2-3 months post-HU. A combination of increased periosteal apposition and endocortical resorption also occurred during HU. The initial HU bout suppressed normal age-related increases in mechanical properties and recovered within 1-2 months. Cancellous compressive strength index (CSI) most closely matched changes in mechanical properties. A second HU bout after two months recovery had a less detrimental effect on pQCT parameters but a greater negative impact on mechanical properties, when compared to pre-HU values. The opposite is true for mechanical properties if loss is characterized relative to aging controls. Recovery after the second HU period did not appear to be significantly affected by a previous bout of HU.

Thesis (M.CM)--Hong Kong Baptist University, 2006. / Dissertation submitted to the School of Chinese Medicine. Includes bibliographical references (leaves 32-35).

Diss. (sammanfattning) Stockholm : Karol. inst., 2006. / Härtill 5 uppsatser.

Thesis (M.S.)--University of Delaware, 2008. / Principal faculty advisor: David A. Barlow, Dept. of Health, Nutrition, & Exercise Sciences. Includes bibliographical references.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / The aim of this research was to evaluate the interlocking nails technique in femoral fractures in dogs and evaluate the use of femoral intramedullary reaming byproducts as an adjuvant to bone healing. Twelve dogs, weighing between 15 and 18 kg, were randomly distributed in three groups according to the type of graft used in the fracture denominated I (control- untreated), II (the byproducts of femoral intramedullary reaming) and III(autogenous cancellous bone). Transverse osteotomy was performed in the middle portion of the femur and posterior osteosynthesis with inrelocking nails. After was carried out the grafting with by-products of intramedullary reaming or autogenous cancellous bone in sufficient quantity to fill the surface of the fracture. In order to compare the performance of the groups treatment were performed radiographic evaluations at 15, 30, 60 and 90 days postoperatively (PO), and clinical evaluation of the daily march up to the 7th postoperative day, and after weekly until the 60th days after surgery. The radiographic analysis revealed that at 30 postoperatively day the mean scores of consolidation in the dogs of the group that received grafts of intramedullary reaming by-products were higher than the other groups. At 45 and 60 postoperative days radiographic images also indicated the superiority of group II in relation to other groups. Clinical evaluation of the march on the 15th postoperative day showed the best performance of the dogs treated with grafting of femoral reaming by-products. 75% of these animals were in grade V of lameness. There was no statistical difference between the grafting of femoral intramedullary reaming byproducts and autogenous cancellous bone in relation to radiographic consolidation scores and degrees of lameness, at different times after surgery. The interlocking nails were considered an efficient method for osteosynthesis of femoral diaphyseal fractures in dogs, without alterations or inconvenience in postoperative period. The grafting of femoral intramedullary reaming byproducts proved to be a viable and effective adjuvant in healing bone fractures of long bones of dogs and we recommend this technique to be evaluated in dogs from traumatic fractures. / O objetivo desta pesquisa foi avaliar a técnica de hastes bloqueadas na osteossíntese de fraturas femorais em cães e avaliar o uso de subprodutos da fresagem intramedular femoral como adjuvante na cicatrização óssea. Foram utilizados 12 cães, pesando entre 15 e 18 kg, distribuídos aleatoriamente em três grupos iguais de acordo com o tipo de enxerto utilizado no foco da fratura, denominados de I (controle não tratado), II (subprodutos da fresagem intramedular femoral) e III (osso esponjoso autógeno). Foi realizada osteotomia transversa na porção média da diáfise femoral e posterior osteossíntese com hastes bloqueadas. Após realizou-se a enxertia de subprodutos da fresagem intramedular ou de osso esponjoso autógeno em quantidade suficiente para preencher a superfície do foco da fratura. Para comparar o desempenho dos grupos tratados, foram realizadas avaliações radiográficas nos períodos de 15, 30, 60 e 90 dias de pós-operatório (PO), e avaliação clínica da marcha diária até o 7º dia de PO, e após semanalmente até os 60 dias de PO. A análise radiográfica revelou que aos 30 dias de PO a média dos escores de consolidação no grupo que recebeu enxerto dos subprodutos fresagem intramedular foi superior à dos outros grupos. Aos 45 e 60 dias de PO as imagens radiográficas também indicaram a superioridade do Grupo II em relação aos demais grupos. A avaliação clínica deambulatória no 15º dia de PO evidenciou o melhor desempenho dos cães tratados com enxerto de subprodutos da fresagem femoral, dos quais 75% dos animais encontravam-se em grau V de claudicação. Não foi encontrada diferença estatística entre a enxertia de subprodutos da fresagem intramedular femoral e de osso esponjoso autógeno com relação aos escores de consolidação radiográfica e graus de claudicação, nos diferentes tempos de PO. As hastes bloqueadas foram consideradas um método eficiente para a osteossíntese de fraturas femorais diafisárias em cães, não possuindo alterações ou inconvenientes no pós-operatório. O enxerto de subprodutos da fresagem intramedular femoral revelou-se uma opção viável e eficiente de adjuvante cicatricial ósseo em fraturas de ossos longos de cães, recomendando-se sua avaliação na rotina clínica.