The thigh bone between the hip joint above and knee joint below is called the femur. Fractures of the femur are the most common ones seen in veterinary practice and usually result from blunt trauma (such as a car accident). There are many types of fractures, ranging from ones that involve the joints, to ones that break across the cartilaginous growth plate and others that involve the shaft or middle of the bone. Traditionally, many femur fractures are repaired using a smooth pin down the centre of the bone called an IM pin. Be careful as the complication rates using an IM pin are high. Use of a plate and screws is far superior. The screws are threaded and engage the bone so that implant loosening is not a likely. More recently a device called an interlocking nail has become available for both cats and dogs. This implant is the ‘gold standard’ in human orthopaedics and can be use for fenmur fractures in animals too.