A dynamic hip screw is a device used to fix a broken hip. One half of the hip joint consists of a rounded piece of bone, called the femoral head, supported by a narrow femoral neck at the top of the femur, or thigh bone. This rounded head sits inside a hollow called the acetabulum, located in the hip bone, where it rotates smoothly, giving rise to the full range of normal hip movement. Sometimes, an injury such as a fall can break the femoral neck, and the femoral head then needs to be fixed on while the bone heals, using a device like the dynamic hip screw. The advantage of using a dynamic hip screw is that it allow patients to walk about soon after surgery, avoiding prolonged bed rest and the associated risks of chest infections and blood clots in the legs.
An operation to fix a broken hip is a type of orthopedic surgery. Orthopedic surgery involves treating problems involving the skeleton and its attached muscles. When an orthopedic implant such as a hip screw is used, the technique is sometimes referred to as sliding screw fixation.
The dynamic hip screw procedure may require a stay in the hospital of several days. Surgery is usually carried out under a general anesthetic, so the patient is asleep during the operation, and no food or drink may be taken in the hours leading up to the procedure. Occasionally, an anesthetic may be given that numbs the body below the waist.
During surgery, the dynamic hip screw is inserted into the femur. It consists of a large screw, which is fixed into the femoral head at an angle, joined on to a metal plate, which is positioned vertically along the shaft of the femur and fastened in place with smaller screws. The surgeon uses X-ray images to ensure accurate positioning of the hip screw.
Following surgery, it is usually possible to eat and drink normally later the same day. A drip will have been connected to a vein in the arm and this is usually removed, although a tube to drain the wound may be left in place a little longer. Painkilling drugs are given to relieve any discomfort.
After about a day of bed rest, patients are encouraged to walk about with the use of walking frames. The dynamic hip screw design means that it is possible for the broken hip to bear weight while it heals. Keeping mobile helps lower the risk of blood clots occurring in the legs and reduces the chance of pressure sores associated with lying in bed. Moving around also helps to stimulate breathing, making it less likely that a chest infection will develop. Once patients are walking independently and safely, it is usually possible for them to return home.