Abstract: A surgical implant for total wrist replacement (TWR) includes a carpal portion and a radial portion to fully encompass both sides of the articulated joint defining wrist movement. The carpal portion is defined by a unitary structure that defines a fused form of the scaphoid, lunate and triquetrum, and bears against the radial portion for permitting articulated motion. The radial portion replaces a distal portion of the natural radius adjacent the wrist, and has the form of a “T” to combine a bearing surface with a stem adapted for implantation in the natural radius. The stem engages a receptacle or bore formed in a truncated end of the natural radius. Both the radial portion and the carpal portion patient-specific members are formed from image scans of the patient's own skeletal structures, and incorporate inverted, contralateral images of healthy structure based on an assessment of deformation in the replaced joint.

Abstract: A fabrication system and method for prosthetic appliances employs imaging of a contralateral skeletal structure for designing a matched, patient specific replacement appliance based on the patient's own skeletal structure. Many skeletal structures are disposed on opposed sides, i.e. left and right sides. A contralateral bone or skeletal member often accurately depicts the individual bone shape of a particular patient more accurately than a generalized approximation. A scan such as a CT or MRI is segmented to apportion a skeletal member for replacement and reconstructed into a 3D (3 dimensional) model. The 3D model is inverted to define the contralateral side, and augmented for surgical connection features and comparison with an anatomic ideal to mitigate imperfections. 3D printing and/or additive manufacturing techniques are invoked with biocompatible materials to render the replacement prosthetic appliance based on the model.