Image analysis for extracapsular hip fracture surgery

PhD ThesisDuring the implant insertion phase of extracapsular hip fracture surgery, a surgeon visually inspects digital radiographs to infer the best position for the implant. The inference is made by “eye-balling”. This clearly leaves room for trial and error which is not ideal for the patient. This thesis presents an image analysis approach to estimating the ideal positioning for the implant using a variant of the deformable templates model known as the Constrained Local Model (CLM). The Model is a synthesis of shape and local appearance models learned from a set of annotated landmarks and their corresponding local patches extracted from digital femur x-rays. The CLM in this work highlights both Principal Component Analysis (PCA) and Probabilistic PCA as regularisation components; the PPCA variant being a novel adaptation of the CLM framework that accounts for landmark annotation error which the PCA version does not account for. Our CLM implementation is used to articulate 2 clinical metrics namely: the Tip-Apex Distance and Parker’s Ratio (routinely used by clinicians to assess the positioning of the surgical implant during hip fracture surgery) within the image analysis framework. With our model, we were able to automatically localise signi cant landmarks on the femur, which were subsequently used to measure Parker’s Ratio directly from digital radiographs and determine an optimal placement for the surgical implant in 87% of the instances; thereby, achieving fully automatic measurement of Parker’s Ratio as opposed to manual measurements currently performed in the surgical theatre during hip fracture surgery

Combining shape and intensity dxa-based statistical approaches for osteoporotic HIP fracture risk assessment

5noAiming to improve osteoporotic hip fracture risk detection, factors other than the largely adopted Bone Mineral Density (BMD) have been investigated as potential risk predictors. In particular Hip Structural Analysis (HSA)-derived parameters accounting for femur geometry, extracted from Dual-energy X-ray Absorptiometry (DXA) images, have been largely considered as geometric risk factors. However, HSA-derived parameters represent discrete and cross-correlated quantities, unable to describe proximal femur geometry as a whole and tightly related to BMD. Focusing on a post-menopausal cohort (N = 28), in this study statistical models of bone shape and BMD distribution have been developed to investigate their possible role in fracture risk. Due to unavailable retrospective patient-specific fracture risk information, here a surrogate fracture risk based on 3D computer simulations has been employed for the statistical framework construction. When considered separately, BMD distribution performed better than shape in explaining the surrogate fracture risk variability for the analysed cohort. However, the combination of BMD and femur shape quantities in a unique statistical model yielded better results. In detail, the first shape-intensity combined mode identified using a Partial Least Square (PLS) algorithm was able to explain 70% of the surrogate fracture risk variability, thus suggesting that a more effective patients stratification can be obtained applying a shape-intensity combination approach, compared to T-score. The findings of this study strongly advocate future research on the role of a combined shape-BMD statistical framework in fracture risk determination.partially_openembargoed_20211027Aldieri A.; Terzini M.; Audenino A.L.; Bignardi C.; Morbiducci U.Aldieri, A.; Terzini, M.; Audenino, A. L.; Bignardi, C.; Morbiducci, U

Bone quality and mesenchymal stromal cell capacity in total hip replacement: Significance for stem osseointegration measured by radiostereometric analysis

Immediate implant stability is a key factor for success in cementless total hip arthroplasty (THA). Cementless techniques were originally designed for middle-aged patients with normal bone structure and healing capacity, but indications have expanded to also include elderly patients. Poor local bone quality, as a result of osteoporosis (OP), and age-related geometric changes of the proximal femur, may jeopardize initial implant stability and lead to increased migration of the implant components thereby compromising biological fixation and osseointegration. Mesenchymal stromal cells (MSCs) are essential in the process of osseointegration. Age-related dysfunction of MSCs is suggested to be a main contributory factor in altered bone repair with aging and therefore may influence osseointegration. The hypothesis of this prospective clinical study was that preoperative bone quality and MSC capacity dictate stability and osseointegration of femoral stems in cementless THA, especially in women after menopause. A total of 61 consecutive women (age <80 yrs) scheduled for cementless THA for primary hip osteoarthritis (OA) were screened for undiagnosed primary or secondary OP, vitamin D insufficiency and other metabolic bone diseases. Prior to THA, patients underwent aspiration of iliac crest bone marrow for analysis of MSC capacity using optimized isolation and culturing protocols. All patients received a cementless total hip implant with an anatomically designed hydroxyapatite (HA) coated femoral stem and ceramic-ceramic bearings. Per-operative biopsy of the intertrochanteric bone was taken for ex vivo analysis of the local cancellous bone quality using micro-CT imaging and biomechanical testing. After surgery, stem migration and osseointegration was monitored for two years using radiostereometric analysis. The majority of women with hip OA was osteopenic or osteoporotic. These conditions were associated with increased periprosthetic bone loss in the proximal femur and impaired initial stability and delayed osseointegration of the femoral stem. Altered intraosseous dimensions of the proximal femur, as well as aging, also had adverse effects on initial stem stability and were associated with delayed osseointegration. Local bone mineral density of the operated hip and the quality of intertrochanteric cancellous bone had less influence than expected on implant migration. The THA females showed differences in the osteogenic properties of their MSCs. Patients with MSCs of low in vitro osteogenic capacity displayed increased stem subsidence after the initial 3 months settling period and thereby delayed osseointegration. The results suggest that decreased skeletal health, such as low systemic BMD and decreased osteogenic properties of bone marrow MSCs, has major influence on early stability and osseointegration of cementless hip prostheses in female patients.Luun laadun ja mesenkymaalisten kantasolujen toiminnan vaikutus lonkan tekonivelen paranemiseen Tekonivelleikkaus on erinomainen toimenpide lonkan nivelrikon hoidossa. Jos leikkausmenetelmäksi valitaan biologisesti kiinnittyvä tekonivel, olennaisinta on saavuttaa komponenttien välitön stabiliteetti. Se mahdollistaa uudisluun kasvun implantin karhennetulle pinnalle. Ikääntymiseen liittyvä luuston haurastuminen ja reisiluun yläosan ydinontelon laajentuminen voivat heikentää tekonivelen komponenttien tukevuutta ja näin hidastaa niiden kiinnittymistä luuhun. Tällainen on mahdollista erityisesti naisilla vaihdevuosien jälkeen. Näiden potilaiden yksilölliset erot luun parantavien solujen (mesenkymaalisten kantasolujen) määrässä ja toiminnassa voivat osaltaan vaikuttaa heidän tekoniveltensä kiinnittymisnopeuteen. Tähän prospektiiviseen kliiniseen tutkimukseen osallistui 61 naispotilasta, joille tehtiin sementöimätön lonkan tekonivelleikkaus nivelrikon takia. Ennen leikkausta potilaille tehtiin seulontatutkimukset osteoporoosin ja muiden luuston aineenvaihduntasairauksien tunnistamiseksi. Leikkauksen yhteydessä potilailta otettiin luuydinnäyte suoliluusta, josta analysoitiin mesenkymaalisten kantasolujen jakautumis- ja erilaistumiskyky luunsoluiksi. Leikkauksen aikana otettiin näyte reisiluun yläosan hohkaluun hienorakenteen ja mekaanisten ominaisuuksien arvioimiseksi. Leikkauksen jälkeen tekonivelen reisikomponentin kolmiulotteista migraatiota ja kiinnittymistä seurattiin radiostereometrisellä analyysillä (RSA) 2 vuoden ajan. Valtaosalla potilaista oli alentunut luuntiheys (osteopenia tai osteoporoosi). Osteopeenisillä ja osteoporoottisilla potilailla todettiin kiihtynyttä luukatoa tekonivelen reisikomponentin ympärillä sekä komponentin lisääntynyttä migraatiota ja hidastunutta kiinnittymistä. Reisiluun yläosan ydinontelon laajentuminen ja potilaan korkea ikä lisäsivät reisikomponentin migraatiota, mutta reisiluun hohkaluun laatu ei vaikuttanut migraation määrään. Potilailla, joilla todettiin mesenkymaalisten kantasolujen alentunut kyky erilaistua luusoluiksi in vitro, todettiin reisikomponentin lisääntynyttä migraatiota ja hidastunutta kiinnittymistä. Tulokset osoittavat, että ikääntymiseen liittyvät luustomuutokset ja yksilölliset erot mesenkymaalisten kantasolujen määrässä ja toiminnassa voivat osaltaan vaikuttaa lonkan tekonivelten paranemiseen naisilla vaihdevuosien jälkeen.Siirretty Doriast

Interlandmark measurements from lodox statscan images with application to femoral neck anteversion assessment

Includes abstract.Includes bibliographical references.Clinicians often take measurements between anatomical landmarks on X-ray radiographs for diagnosis and treatment planning, for example in orthopaedics and orthodontics. X-ray images, however, overlap three-dimensional internal structures onto a two-dimensional plane during image formation. Depth information is therefore lost and measurements do not truly reflect spatial relationships. The main aim of this study was to develop an inter-landmark measurement tool for the Lodox Statscan digital radiography system. X-ray stereophotogrammetry was applied to Statscan images to enable three-dimensional point localization for inter-landmark measurement using two-dimensional radiographs. This technique requires images of the anatomical region of interest to be acquired from different perspectives as well as a suitable calibration tool to map image coordinates to real world coordinates. The Statscan is suited to the technique because it is capable of axial rotations for multiview imaging. Three-dimensional coordinate reconstruction and inter-landmark measurements were taken using a planar object and a dry pelvis specimen in order to assess the intra-observer measurement accuracy, reliability and precision. The system yielded average (X, Y, Z) coordinate reconstruction accuracy of (0.08 0.12 0.34) mm and resultant coordinate reconstruction accuracy within 0.4mm (range 0.3mm – 0.6mm). Inter-landmark measurements within 2mm for lengths and 1.80 for angles were obtained, with average accuracies of 0.4mm (range 0.0mm – 2.0 mm) and 0.30 (range 0.0 – 1.8)0 respectively. The results also showed excellent overall precision of (0.5mm, 0.10) and were highly reliable when all landmarks were completely visible in both images. Femoral neck anteversion measurement on Statscan images was also explored using 30 dry right adult femurs. This was done in order to assess the feasibility of the algorithm for a clinical application. For this investigation, four methods were tested to determine the optimal landmarks for measurement and the measurement process involved calculation of virtual landmarks. The method that yielded the best results produced all measurements within 10 of reference values and the measurements were highly reliable with very good precision within 0.10. The average accuracy was within 0.40 (range 0.10 –0.80).In conclusion, X-ray stereophotogrammetry enables accurate, reliable and precise inter-landmark measurements for the Lodox Statscan X-ray imaging system. The machine may therefore be used as an inter-landmark measurement tool for routine clinical applications

Recent trends, technical concepts and components of computer-assisted orthopedic surgery systems: A comprehensive review

Computer-assisted orthopedic surgery (CAOS) systems have become one of the most important and challenging types of system in clinical orthopedics, as they enable precise treatment of musculoskeletal diseases, employing modern clinical navigation systems and surgical tools. This paper brings a comprehensive review of recent trends and possibilities of CAOS systems. There are three types of the surgical planning systems, including: systems based on the volumetric images (computer tomography (CT), magnetic resonance imaging (MRI) or ultrasound images), further systems utilize either 2D or 3D fluoroscopic images, and the last one utilizes the kinetic information about the joints and morphological information about the target bones. This complex review is focused on three fundamental aspects of CAOS systems: their essential components, types of CAOS systems, and mechanical tools used in CAOS systems. In this review, we also outline the possibilities for using ultrasound computer-assisted orthopedic surgery (UCAOS) systems as an alternative to conventionally used CAOS systems.Web of Science1923art. no. 519

Artificial neural network analysis of bone quality DXA parameters response to teriparatide in fractured osteoporotic patients

Teriparatide is a bone-forming therapy for osteoporosis that increases bone quantity and texture, with uncertain action on bone geometry. No data are available regarding its influence on bone strain. To investigate teriparatide action on parameters of bone quantity and quality and on Bone Strain Index (BSI), also derived from DXA lumbar scan, based on the mathematical model finite element method. Forty osteoporotic patients with fractures were studied before and after two years of daily subcutaneous 20 mcg of teriparatide with dual X-ray photon absorptiometry to assess bone mineral density (BMD), hip structural analysis (HSA), trabecular bone score (TBS), BSI. Spine deformity index (SDI) was calculated from spine X-ray. Shapiro-Wilks, Wilcoxon and Student's t test were used for classical statistical analysis. Auto Contractive Map was used for Artificial Neural Network Analysis (ANNs). In the entire population, the ameliorations after therapy regarded BSI (-13.9%), TBS (5.08%), BMD (8.36%). HSA parameters of femoral shaft showed a worsening. Dividing patients into responders (BMD increase &gt;10%) and non-responders, the first presented TBS and BSI ameliorations (11.87% and -25.46%, respectively). Non-responders presented an amelioration of BSI only, but less than in the other subgroup (-6.57%). ANNs maps reflect the mentioned bone quality improvements. Teriparatide appears to ameliorate not only BMD and TBS, but also BSI, suggesting an increase of bone strength that may explain the known reduction in fracture risk, not simply justified by BMD increase. BSI appears to be a sensitive index of TPD effect. ANNs appears to be a valid tool to investigate complex clinical systems

Health Care for Older Adults

In recent decades, life expectancy has been increasing. This is a historical milestone in the history of humanity. We have never lived so long before. In these circumstances, giving the best care to older adults efficiently is one of the greatest challenges of developed countries. This book explores different initiatives that result in the improvement of health conditions of older adults, such as multicomponent physical exercise programs, interventions that try to avoid loneliness and social isolation, and multidisciplinary assessment, and the treatment of frailty and other geriatric syndromes, of the elderly in various settings such as the Emergency Unit, Orthogeriatrics, and Oncogeriatrics. This book offers different manuscripts to readers, each trying to improve life satisfaction, quality of life, and life expectancy in older adults in different scenarios. It is up to us to achieve these goals. We are sure that these interesting chapters will contribute to improving clinical practices. Following the completion of the Special Issue "Health Care for Older Adults" for the international Journal of Environmental Research and Public Health, the Guest Editors felt the satisfaction of having reached 18 published manuscripts and the possibility of transforming this volume into a book. This book was born from the need to show how health and social advances have increased human longevity as never before. We live longer, knowing more and more the epigenetic mechanisms of this longevity, as extended aging also coexists with the least favorable aging trajectories. Among them, a syndrome stands out from the gerontological and geriatric perspective: frailty. Due to the pandemic, a social problem has increased its presence in clinical practice: ageism. Older adults have found it difficult to access the necessary clinical resources due to the simple matter of age. However, at this moment, we are able to detect and to reverse frailty. In the same way, we should aim to prevent loneliness and social isolation, involved in social frailty. Geriatric syndromes are underdiagnosed and undertreated, but clinical and geriatric knowledge provide diagnostic tools and non-pharmacological approaches to prevent and to treat them. All health professionals working together in an interdisciplinary team could improve the clinical practices to develop a quality health care for older adults, improving their life satisfaction and quality of life perception too

3D Digital Methods for Quantitative CT-based Trabecular Vertebral Bone Texture and Microarchitecture Analysis for Fracture Risk

This work describes a new approach to building 3D digital bone tissue phantoms with microarchitecture features that capture the variability and complexity of human vertebral trabecular bone