A femoral head arthroplasty system can comprise a femoral prosthesis comprising a mounting plate having a first side and an opposed second side. An adapter can extend from the second side of the mounting plate. An implant body can extend from the first side of the mounting plate. The implant body can extend from the mounting plate by a distance no greater than 90 mm. The femoral head arthroplasty system can further comprise a femoral head replacement having a generally spherical surface and comprising a recess that is shaped to complementarily receive the adapter of the femoral prosthesis.

A femoral head arthroplasty system can comprise a femoral prosthesis comprising a mounting plate having a first side and an opposed second side. An adapter can extend from the second side of the mounting plate. An implant body can extend from the first side of the mounting plate. The implant body can extend from the mounting plate by a distance no greater than 90 mm. The femoral head arthroplasty system can further comprise a femoral head replacement having a generally spherical surface and comprising a recess that is shaped to complementarily receive the adapter of the femoral prosthesis.

An expandable interbody device used as a prosthesis during spinal surgery. The expandable interbody device is configured to be inserted into the space between spinal discs to provide stability. The expandable interbody device includes a drive block, a top endplate, a bottom endplate, a first drive arrangement, and a second drive arrangement; the first drive arrangement includes a first drive screw, a first left side slide, a second left side slide, a first upper left side linkage, a second upper left side linkage, a first lower left side linkage age and a second lower left side linkage; and the second drive arrangement includes a second drive screw, a first right side slide, a second right side slide, a first upper right side linkage, a second upper right side linkage, a first lower right side linkage and a second lower right side linkage.

An expandable interbody device used as a prosthesis during spinal surgery. The expandable interbody device is configured to be inserted into the space between spinal discs to provide stability. The expandable interbody device includes a drive block, a top endplate, a bottom endplate, a first drive arrangement, and a second drive arrangement; the first drive arrangement includes a first drive screw, a first left side slide, a second left side slide, a first upper left side linkage, a second upper left side linkage, a first lower left side linkage age and a second lower left side linkage; and the second drive arrangement includes a second drive screw, a first right side slide, a second right side slide, a first upper right side linkage, a second upper right side linkage, a first lower right side linkage and a second lower right side linkage.