Method and apparatus for treating bone fractures, and/or for fortifying and/or augmenting bone, including the provision and use of composite implants, and novel composite structures which may be used for medical and non-medical applications

A method of forming a composite comprising steps of:

• i) inserting a balloon or containment bag into a cavity;
• ii) injecting an injectable matrix material into the balloon or containment bag for filling a space in the balloon or containment bag with the injectable matrix material;
• and
• iii) transforming the injectable matrix material from a flowable state to a set state;
• wherein the balloon or containment bag includes one or more rods before the step of inserting, or the method includes inserting one or more rods into the balloon or containment bag after the step of inserting;
• wherein each of the one or more rods has a bending modulus of 2 to 80 GPa and includes one or more fibers and a polymer;
• wherein the concentration of the rods in the composite is 5 volume percent to about 85 volume percent of the composite and the one or more fibers are present in an amount of about 5 volume percent to about 75 volume percent of the composite.