The shaft of the femur is a very strong structure and well padded with the large muscles which propel the body in gait so it is rare for it to be fractured as this requires high levels of force. Motorcycle, bicycle or car accidents are the commonest sources of this kind of fracture and they are most common in younger people. When the femoral shaft fractures there is a significant amount of bleeding into the local tissues, the fragments may damage the surrounding muscles as they move passed each other and this can cause the muscles to go into spasm. High levels of pain and disability mean that hospitalisation is essential.
Conservative treatment used to be the main technique of managing these fractures, with many weeks on traction in bed, but this has all been superseded by internal fixation surgery. Surgeons ream down the centre of the bone and typically place a nail down the length of the bone to stabilise the fracture with screws at the knee end to prevent rotation around the nail. Once the operation has been performed the physiotherapist will assess the patient, mostly concentrating on whether they can get their quadriceps muscle to activate despite the injury and pain. Movements of the feet and an attempt at gentle bending of the knee will be encouraged.
Once the patient is medically stable and their pain is under control the physio will get them up with an assistant and elbow crutches. The surgeon will have indicated how much weight to put on the leg and typically the patient is allowed to take partial body weight if the fracture fixation is stable. This is more functional and the weight on the leg stimulates the bone to heal. The physio will teach the patient an initial easy and safe gait, placing the crutches ahead of the body, moving the operated leg up to the crutches and then bringing the unaffected leg up to it. Once the patient is safe they often naturally progress onto a more advanced gait and can walk much more quickly.
Once mobility and gait are good enough the patient is discharged home to rehabilitate themselves to a greater or lesser degree. Most patients improve steadily back to normal function by themselves with a bit of advice but sometimes there are limitations which need physiotherapy assessment and treatment. Hip abductor weakness is common and may need the physio to prescribe hip strengthening exercises.