Abstract: System, including method and apparatus, for applying traction to a patient's limb using constant-force springs. The constant-force springs may include one or more main springs that apply a base tractive force and at least one supplementary spring that can apply a supplementary tractive force to the limb. The at least one supplementary spring may be changeable reversibly between uncoupled and coupled configurations while the base tractive force is applied continuously to the limb and without repositioning the limb, thereby providing discrete adjustment of traction force while the limb remains in traction.

Abstract: System, includes devices, methods, and kits, for fixing bone and/or repairing connective tissue associated with bone using a fastener constructed as a bone nail that includes at least one helical ridge having a large pitch. The large pitch permits the nail to be driven into bone by application of axial force to the nail, to secure the nail in the bone. In some embodiments, the bone nail may have a variable pitch that decreases toward the trailing end of the nail.

Abstract: Embodiments of the present invention provide rotationally asymmetric bone screws. Embodiments of the present invention provide mechanisms that reduce the bending stiffness of conventional shaft bone screws in order to yield a less-rigid fixation construct. Such a less-rigid construct enables a controlled amount of motion at a fracture site which in turn promotes bone healing. As a means to reduce the bending stiffness of positive-locking bone screws, embodiments of the present invention provide a bone screw having a non-circular cross-section over parts of the screw length and/or longitudinal slots along at least a portion of the bone screw.

Abstract: Systems and methods for providing dynamic mechanical loading and mechanical property assessment of tissue cultures in open dish cultures are provided. An actuator may be provided under a cell culture dish for driving the dish upward toward a fixed post member, thereby providing controlled compression of a tissue sample.