Biomechanics of the Wrist and Distal Radioulnar Joint. The quantification of joint mechanics as it relates to the wrist and distal radioulnar joint are being carried out to further our understanding of normal mechanics and pathomechanics related to trauma. This includes a continuing effort to define the ligamentous anatomy of these joints as well as characterizing the geometry of the bones that contribute to the joints. From this, studies of the material and constraint properties of these ligaments are derived, as well as studies of the kinematics (motion without reference to force)of the bones involved. This has resulted in the development of a computer-driven cadaveric forearm motion simulator, which has the capability of actively generating motion in a cadaver specimen while simultaneously recording bony displacement, tendon excursion, tendon load and resultant torque data. Translational research is also underway with colleagues in the Department of Radiology to quatitate diplacement and force in patients with disorders of the distal radioulnar joint.
The Role of Mechanoreceptors in the Wrist Joint. Mechanoreceptors are specialized nerve endings which respond to mechanical stimuli such as pressure, compression, and stretch. A recent discovery of the relationship of two wrist joint nerves, the anterior (AIN) and posterior (PIN) interosseous nerves, has led to the development of a unique model which allows the study of these mechanoreceptors in-vivo. This research project is divided into three phases. The first phase is to characterize the morphology, location, and distribution of mechanoreceptors in key ligaments associated with the AIN and PIN through immunohistochemical techniques. This is carried out on cadaveric specimens with collaborations with colleagues in the Biomedical Imaging Resource and the Image Morphometry Laboratory. The second phase is in-vivo recording of transmitted impulses of the AIN and PIN in patients undergoing elective denervation of the wrist for intractible pain, in collaboration with Neurology. The third phase is a comprehensive analysis of in-vivo proprioception in normal volunteers, in collaboration with the Motion Analysis Laboratory and colleagues in Physical Medicine and Rehabilitation.