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 NIH 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 requires 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. We can then 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) functional movemnts. This past year focused on expanding the VFA toolbox in three primary areas; bone shape/muscle volume analysis, automatic segmentation methodological development, and dynamic cartilage contact. This has been augmented by our collaboration with The University of Queensland. We have been able to leverage data collected outside this protocol to extend our study on knee joint shape development in childhood and our tool development work in the area of automatic muscle segmentation. The automatic segmentation tools within the VFA toolbox have been further expanded with collaborations between our group, CIT (NIH), and IMT Atlantique. With the support of our collaborator Dr. Barry Boden (Rockville Orthopeadics), we have expanded the toolbox to incorporate the evaluation of individuals with repeat patellar dislocations. The Relationship Between Patellofemoral (PF) Kinematics and Demographics in Adults with Idiopathic PF Pain. We used the large normative and patient PF kinematic databases, collected under this protocol, to better understand the influence demographics play on PF kinematics. In doing so, we can build a statistical framework for analysis that compensates for these potential confounding variables. A relationship was found and this work establishes how all studies in this area must be designed moving forward. The study concluded with a published manuscript. PF Shape in Adults with Recurrent Patellar Dislocation. The role of femoral shape changes in recurrent dislocation is well known. However, past studies in the area have 3 main weaknesses; they primarily ignore patellar shape, they do not use true normative controls, and they do not compensate for the confounding demographic effects. Thus, our study aimed to create new tools for evaluating PF shape in patients with a history of recurrent dislocation. To demonstrate the utility of these tools, PF shape was evaluated in a cohort of patients with a history of recurrent patellar dislocation and the results were compared to a group of matched controls with no history of knee pathology or injury. A paper summarizing these results is in progress PF Kinematics in Adolescents with PF Pain We compared the complete six degree-of- freedom PF kinematics from a group of adolescents diagnosed with PF pain syndrome to those from a matched asymptomatic population. The kinematic and pain profiles of these adolescents were followed as they matured into adulthood. We developed new tools to quantify PF shape parameters unique to adolescents. Using these tools, we explored the role of PF morphology plays in this patient cohort. The primary finding over the past year is that adolescents with PF pain demonstrate unique PF kinematics, relative to adults, with a paper published in this area. We have used the expertise and tools gained in this area in our collaboration with the University of Queensland and a paper regarding adolescent muscle control is currently in review. Participants were recruited based on the Queensland IRB and the VFA toolbox played a key role in quantifying key knee joint musculoskeletal attributes. A paper is now in final review with these collaborators. We are in the process of quantifying the changes in PF morphology with development and data from both of the above projects have helped establish a large database of knee MR image sets in a group of developing/developed controls ages 6-21. Musculoskeletal Architecture in children with OBPP This study provided a more complete understanding of shoulder musculoskeletal architecture changes in children/adolescents with OBPP, enhancing our understanding of the natural history of OBPP. This work has been completed. 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. Two abstracts have been accepted for this work. These data are now being shared with our CIT collaborators and new segmentation algorithms are being developed. PF Dynamic Joint Contact The objective of this study is the continued improvement dynamic joint contact tools within the VFA toolbox. This project established the first validated database defining dynamic, in vivo PF cartilage contact kinematic parameters, acquired during volitional activity in healthy subjects. This provides crucial data for future studies of PF 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 continuing in the evaluation of PF contact during various activities and within various populations. These tools are the basis of data analysis for two other protocols. Using MRI and US to Diagnose Hamstring Tears. We are collaborating with Diagnostic Radiology to determine the optimal imaging sequences that will allow for a coordinated evaluation of hamstring tears. We aimto build a combined set of MR-US imaging and analysis tools for the quantification of musculoskeletal injury. Mechanisms of ACL injury The VFA toolbox was used to support an outside collaboration quantifying the mechanisms of ACL injury. This work was awarded the 2021 Kappa Orthopaedic Research Education Foundation (OREF) Clinical Research Award and a paper has been published.