One in four Canadians aged 50 or more, men equally as women, develop osteoporosis, a condition of decreased bone mass that can lead to bone fragility and low-impact fractures-particularly of the hip, spine and wrist.
Typically, a low-impact osteoporotic hip fracture breaks across the neck of the femur, which often disrupts blood supply to the femural head because the two bone ends become misaligned.
Hip fractures can also be the result of a high-impact injury due to a motor vehicle accident, contact sports injury, fall from a height or other type of serious trauma. Typically, these patients are under age 50.
High-impact hip fractures usually occur just below the neck of the femur (called an intertrochanteric fracture). Occasionally, extremely violent trauma can crack the bone across its shaft (called a subtrochanteric fracture). Neither fracture poses much risk to the bone’s blood supply to the femural head.
Signs and Symptoms of Osteoporosis
Osteoporosis is a disease without any external symptoms that progresses slowly over the span of many years. If the femoral neck loses mass and becomes fragile, it can fracture as a result of a fall or sometimes following a simple twisting motion. One of the most important considerations after a femoral neck fracture is how badly displaced are the two bone ends and how badly disrupted is the blood supply to the femoral head. When blood flow is diminished, the fracture very likely will not heal and the femoral head will eventually die.
Diagnosis
Whether low- or high-impact, a hip fracture is a medical emergency, which is initially diagnosed through medical history, a physical examination by the attending physician and then confirmed through x-rays. Patients experience pain in the hip, buttocks and groin. The affected leg often appears shorter than the other and frequently turns inward. Bruising over the affected hip may appear later.
Treatment
A hip fracture requires surgical treatment. Your surgeon will decide on a procedure and device best suited to the fracture’s type and severity.
To treat a femoral-neck fracture as a result of osteoporosis, the surgeon almost always performs a procedure called a “femoral hemiplasty,” during which the femoral neck and head are removed and replaced by a metal-alloy implant. Misalignment of the bone ends, which is very common in this type of fracture, means that blood vessels that feed the femoral head have probably been torn and the bone tissue above the fracture will die and become brittle.
High-impact hip fractures usually occur in the tibia proper, across some of the thickest and densest bone in the body. Thus there is little misalignment along the fracture line. Orthopaedic surgeons have an array of nails, screws and plates to hold the bone in place while it mends.
Cannulated screws: several screws or pins are placed across the fracture. Compression-screw plate: a metal sliding compression screw and plate holds the bone in place while it mends.
Intramedullary nail: a metal nail may be inserted down into the bone shaft to hold the broken bone in place. A second screw or nail in the head of the femur improves fixation, fusion.
Prosthesis with femoral stem: the ball of the bone is replaced with a metal ball and stem, prosthesis. The hip socket is not replaced.
The surgery can take several hours. Afterward, patients are taken to the recovery room where they are monitored for the next few hours. Once the effects of anesthesia have worn off, patients return to their hospital room.
One of the most common complications after surgery is deep vein thrombosis (DVT), which can result from the complete immobility imposed by anesthesia. Typically, blood clots form in one of the three large veins that drain blood from the leg. Symptoms include pain and redness in the affected leg’s calf muscles and sometimes swelling. The danger of DVT is that the clot can loosen and begin to circulate. Eventually the clot may become lodged in the main arteries to the lungs, which is a life-threatening emergency. To counter the problem, patients are asked to pump their ankles regularly to promote blood circulation. Patients may also be given special support hose to improve circulation and a blood thinner to prevent or dissolve a clot.
Most patients can begin to stand and walk a few steps with the help of a walker or physiotherapist the day after surgery. Rehab begins in earnest from that point. Physiotherapists teach patients special exercises designed to restore hip flexibility and muscle strength.