Virtual Functional Anatomy

Clinical Center

Investigators

Linked publications, trials & patents

Abstract

Although the primary aim of diagnosing and treating musculoskeletal impairments is to restore functional three-dimensional (3D) movements, the majority of the quantitative diagnostic and evaluation tools available to the clinician have remained static and two dimensional. Thus, the current focus is to develop and ultimately validate a combined set of tools that will enable the accurate and precise measurement, analysis and visualization of 3D static and dynamic musculoskeletal anatomy (i.e., bone shape, skeletal kinematics, tendon and ligament strain, muscle force, and joint space). To accomplish this, the MR imaging and analysis capabilities already developed will be combined with highly accurate, imaging-based measurement and registration methodologies in order to non-invasively quantify complete joint anatomy and tissue dynamics during functional movements. Additionally, these tools will enable the quantification of 3D bone shape so that the effect that alterations joint and tissue dynamics have on bone shape can be quantified. Accomplishing the aims of the VFA initiative will fill an important knowledge gap that exists between the relationship of normal or impaired joint structure/function and the functional movement limitations associated with performing activities of daily living. In doing so, it will position the National Institutes of Health as an international leader in diagnostic evaluation of musculoskeletal impairments by advancing musculoskeletal diagnostic and evaluation tools from primarily static 2D tools to dynamic tools that can quantify 3D musculoskeletal function during dynamic tasks. Due to the natural tiered structure of this research, two primary paths are currently being pursued, one based using the VFA project in its current state to evaluate both normative and impaired joint kinematics and the other is the continued development of the VFA tools so that full musculoskeletal kinetics can be evaluated. The latter will require the development of methodologies for creating 3D digital images of loaded and moving joint tissues (bone, cartilage, and connective tissues) to reveal joint contact patterns and tissue loads. As part of the kinematics branch, the variability of bone shape and the sensitivity of defined joint posture (translation and rotation of one bone relative to another) to osteo-based coordinate system will be quantified. We intend to use these capabilities to document and evaluate the function of normal and impaired joint structures (e.g., Cerebral Palsy, Ehlos Danof syndrome, and patellar tracking syndrome) under simulated conditions experienced during activities of daily living. The primary focus of this past year has focused on the etiology of PF pain in both adolescents and adults. This has been augmented by our collaboration with The University of Queensland. The collaboration focusses on muscle function in adolescents with PF pain. We have been able to leverage these data to extend our study on knee joint shape development in childhood and our tool development work in the area of automatic muscle segmentation. This toolbox development has been further expanded with collaborations between our group, CIT (NIH), and IMT Atlantique. These collaborations are focused on creating automatic-segmentation routines for the 3D MR images of the knee. Studies evaluating musculoskeletal architectural changes in the shoulders of children with OBPP and dynamic cartilage contact at the patellofemoral joint remain ongoing. Numerous conference presentations and papers were produced over the year based on this work. Patellofemoral Kinematics in Adolescents with Patellofemoral Pain The objective of this study was to use the full power of the VFA toolbox to elucidate the potential kinematic, kinetic, and morphological alterations at the knee joint that result in anterior knee pain and to better explain the mechanisms behind specific treatment options in adolescents. This year we focused on completing a paper that compared the maltracking of adolescents to the of adults with patellofemoral pain. Patellofemoral Pain in Adults: Based on our extensive work in this area using data collected under this protocol, a systematic review was completed and is now in published (AJSM). This work is continuing with a paper in review evaluating the influence of demographic factors in patellofemoral kinematics Musculoskeletal Architecture in children with OBPP The purpose of this study was to provide a more complete understanding of the changes to the shoulder musculoskeletal architecture in children/adolescents with OBPP in order to better define the natural history of OBPP and improve interventional outcomes. This purpose was accomplished through a global research approach that incorporated numerous quantitative tools for assessing the static and dynamic architecture and capabilities of the shoulder joint. Segmentation of high resolution 3D MR images was used to define muscle volumes and skeletal shape parameters. These data were captured for children/adolescents with OBPP, as well as typically developing children. Based on a data-sharing agreement with Pierre-Henri Conze of Brest France, these data have been successfully used to develop automated segmentation methods for delineating shoulder muscles from MR images. A manuscript has now been published in Computerized Medical Imaging and Graphics. Patellofemoral Dynamic Joint Contact As part of the long term goal of the this protocol to optimize diagnosis, treatment, and evaluation of patients suffering from specific musculoskeletal impairments, the objective of this study was to use the new advances within the virtual functional anatomy toolbox to evaluate how alterations in patellofemoral contact mechanics relate to PFPS. This project established the first validated database defining dynamic, in vivo patellofemoral cartilage contact kinematic parameters, acquired during volitional activity in healthy subjects. This provides crucial data for future studies of patellofemoral pain and OA. In addition, these data can be used for validation of, or as input to, future computational models. It is a clear advancement over previous studies that have little to no validation and have typically been limited to static analyses, cadaver studies, animal-based methodologies, or generic computational models. Work is ongoing to improve the algorithms