An Intramedullary Distraction Osteotomy (IM DO) apparatus and corresponding methods are disclosed that allow for the patient or another to lengthen residual bone. The apparatus may be inserted into the intramedullary canal of the residual bone and may be lengthened through the application of a traction force. The apparatus protrudes from the body through a single percutaneous site. Lengthening of the amputated limb is achieved by the application of a controlled traction force that is generated by turning a lengthening knob external to the percutaneous site. One or more additional screw segments may be utilized to assist in limb lengthening. The traction force serves to separate a distal bone segment from a proximal bone segment at a specified, controllable rate, allowing new bone growth to fill in the resulting gap. Components of the apparatus provide support and alignment to the residual bone during both the lengthening and consolidation phases. External components of the apparatus may be removed after desired limb length has been achieved, reducing the risk of infection and improving patient mobility.