Orthopedic management of the extremities in patients with Morquio A syndrome.

BackgroundMusculoskeletal involvement in Morquio A syndrome (mucopolysaccharidosis IVA; MPS IVA) contributes significantly to morbidity and mortality. While the spinal manifestations of the disorder have received considerable attention in the literature, there have been few reported studies to date to guide the management of the orthopedic problems associated with the lower and upper extremities.PurposeThe objective was to develop recommendations for the management of the extremities in patients with Morquio A syndrome.MethodsA group of specialists in orthopedics, pediatrics and genetics with experience in the management of Morquio A patients convened to review and discuss current clinical practices and to develop preliminary recommendations. Evidence from the literature was retrieved. Recommendations were further refined until consensus was reached.Results and conclusionsThis present article provides a detailed review and discussion of the lower and upper extremity deformities in Morquio A syndrome and presents recommendations for the assessment and treatment of these complications. Key issues, including the importance of early diagnosis and the implications of medical therapy, are also addressed. The recommendations herein represent an attempt to develop a uniform and practical approach to managing patients with Morquio A syndrome and improving their outcomes

Developing a cationic contrast agent for computed tomographic imaging of articular cartilage and synthetic biolubricants for early diagnosis and treatment of osteoarthritis

Osteoarthritis (OA) causes debilitating pain for millions of people, yet OA is typically diagnosed late in the disease process after severe damage to the articular cartilage has occurred and few treatment options exist. Furthermore, destructive techniques are required to measure cartilage biochemical and mechanical properties for studying cartilage function and changes during OA. Hence, research and clinical needs exist for non-destructive measures of cartilage properties. Various arthroscopic (e.g., ultrasound probes) and imaging (e.g., MRI or CT) techniques are available for assessing cartilage less destructively. However, arthroscopic methods are limited by patient anesthesia/infection risks and cost, and MRI is hindered by high cost, long image acquisition times and low resolution. Contrast-enhanced CT (CECT) is a promising diagnostic tool for early-stage OA, yet most of its development work utilizes simplified and ideal cartilage models, and rarely intact, pre-clinical animal or human models. To advance CECT imaging for articular cartilage, this dissertation describes further development of a new cationic contrast agent (CA4+) for minimally-invasive assessment of cartilage biochemical and mechanical properties, including glycosaminoglycan content, compressive modulus, and coefficient of friction. Specifically, CA4+ enhanced CT is compared to these three cartilage properties initially using an ideal bovine osteochondral plug model, then the technique is expanded to examine human finger joints and both euthanized and live mouse knees. Furthermore, CECT attenuations with CA4+ map bovine meniscal GAG content and distribution, signifying CECT can evaluate multiple tissues involved in OA. CECT's sensitivity to critical cartilage and meniscal properties demonstrates its applicability as both a non-destructive research tool as well as a method for diagnosing and monitoring early-stage OA. Additionally, CECT enables evaluation of efficacy for a new biolubricant (2M TEG) for early-stage OA treatment. In particular, CECT can detect the reduced wear on cartilage surfaces for samples tested in 2M TEG compared to samples tested in saline (negative control). With its sensitivity to cartilage GAG content, surface roughness, and mechanical properties, CA4+ enhanced CT will serve as a valuable tool for subsequent in vivo animal and clinical use

Subjektive Bildqualität digitaler Panoramaschichtaufnahmen in Relation zur Exposition

Die Zielsetzung dieser Studie war es, für digitale Panoramaschichtaufnahmen die Relation der subjektiven Bildqualität zur Exposition zu bestimmen. An Hand von Humanpräparataufnahmen konnten bei Standardwerten sowie experimentellen Variationen der Expositionsdaten weiterhin Effekte der intentionellen Unterexposition sowie der Strahlenaufhärtung auf die subjektive Bildqualität quantifiziert werden. Die Herstellung der Aufnahmen erfolgte auf einem Sirona Orthophos DS. Dabei wurden 37 Aufnahmen mit Expositionswerten von 60 kV/9 mA - 84 kV/13 mA aus dem Herstellerprogramm erzeugt und mit Hilfe einer modifizierten Steuerungssoftware zusätzliche PSA mit experimentellen Einstellungen von 60 kV/3 mA - 90 kV/11 mA hergestellt. Für die Beurteilung und Auswertung der subjektiven Bildqualität wurde eine individuelle Software (Eldoredo V2.2) entwickelt. 39 Zahnärzte und 5 MTRA beurteilten die Aufnahmen damit an einem Monitor unter standardisierten Bedingungen. Ein iterativer Beurteilungsprozess erlaubte, eine Serie von 1369 (37 x 37) PSA-Abbildungspaaren darzustellen. Für jedes Paar entschieden die Untersucher an Hand definierter Kriterien, ob eine PSA hinsichtlich der subjektiv beurteilten Bildqualität vorzuziehen oder Äquivalenz gegeben sei. Nach statistischer Aufarbeitung der Einzelentscheidungen ließ sich damit für jede Expositionsstufe ein Index der Bildqualität berechnen. Bei Expositionswerten in einem Bereich von 60 kV/9 mA - 69 kV/15 mA der Herstellersoftware und 60 kV/5 - 15 mA sowie 70 kV/5 - 15mA der experimentellen Software fanden sich dabei keine signifikanten Verteilungsunterschiede der Bildqualität. Eine intentionelle Unterexposition bei digitalen PSA-Geräten, etwa bei Kindern oder häufigen Wiederholungsaufnahmen, kann nach den vorliegenden Ergebnissen vertreten werden, ohne dass es dabei zu einer signifikanten Verschlechterung der Bildqualität kommt. Damit ist im Gegensatz dazu bei einer Strahlenaufhärtung in dem untersuchten digitalen System stets zu rechnen. Insgesamt zeigen die Ergebnisse, dass auch digitale PSA-Systeme beachtliche Reserven hinsichtlich der Dosisminimierung aufweisen können.The aim of this study was to describe the relation of the subjective image quality of digital panoramic radiographs in relation to exposure. In addition, variations of exposure were compared to standard settings, thus evaluating the effects of intentional underexposure on the achievable image quality. A Sirona Orthophos DS unit was used to produce 37 digital panoramic images of a human skull. Exposure values ranged from 60 kV/9 mA to 84 kV/13 mA in the conventional and 60 kV/3 mA to 90 kV/11 mA in the experimental setting. Assessment and evaluation of the subjective image quality were performed with an HTML-based protocol. 39 dentists and 5 radiographic assistants had to assign their preference of an image or equality in 1,369 (37x37) image pairs. The decisions were computed to a quality index for each exposure setting. Statistical analysis demonstrated no significant differences of image quality between 60 kV/9 mA - 69 kV/15 mA in the conventional and 60 kV/5 to15 mA as well as 70 kV/5 to 15 mA in the experimental setting. Following these results, a considerable dose reduction by the means of intentional underexposure can be achieved without any loss of image quality. By reducing the absorbed doses, an increase of kV values up to 80 kV and more is also correlated with dose reduction. However, those images showed high significant loss of quality. In summary, the results demonstrate an equivalent image quality of digital panoramic images over a very wide range of exposure values. The feasible dose reduction might be of interest not only in individuals (minors, repeated images), but also in defining general principles of panoramic imaging