The Acumed 4.0 mm Cannulated Screw System is designed to provide a minimally invasive method of anatomical fixation. The system consists of screws, washers, and instruments designed to provide fixation for fractures, fusions, and osteotomies of large and small bones appropriate for the size of the device. The 4.0 mm screws are available in lengths ranging from 10 mm to 72 mm to accommodate various indications and patient anatomy. All screws and washers are made of titanium alloy per ASTM F136. Screws are cannulated in order to be used over a guide wire with a cancellous thread form. Partially threaded screws are offered in one-half and one-third length threads. Cannulation is intended for minimally invasive percutaneous insertion. Partially threaded screws may be used to lag one bone fragment to another, where the far bone fragment is captured by the threads of the screw and pulled toward the near cortex fragment on the head side of the screw.