Abstract: An endoprosthesis is proved which includes an elongate housing having a drive secured through a threaded drive shaft to an extension shaft therein, the drive operable to cause the extension shaft to move axially with respect to the body, and the extension shaft and housing configured to be securable to a bone to act as a prosthetic replacement for removed bone. An operating system for the endoprosthesis is also provided.

Abstract: An endoprosthesis (1) is proved which includes an elongate housing (3) having a drive (5) secured through a threaded drive shaft (7) to an extension shaft (9) therein, the drive (5) operable to cause the extension shaft (9) to move axially with respect to the body, and the extension shaft (9) and housing (3) configured to be securable to a bone to act as a prosthetic replacement for removed bone. The drive (5) is operable in a step-wise fashion through a control circuit (50) which includes an inductive coil (52). The control circuit (50) is configured to provide a predetermined output upon receiving power through the inductive coil (52) and is hardwired. An operating system for the endoprosthesis (1) is also provided and includes an external operating unit which supplies an alternating magnetic field to the internal inductive coil (52) and which is controlled by a microcontroller.