My mother just had a partial hip replacement. I guess it was like having a tooth capped. Just the top of his femur was replaced. She ended up with a hip fracture afterwards. Is this common?

It sounds like your mother had an operation called joint resurfacing. This type of operation has been around since the 1930s. It has come and gone based on problems afterwards and materials available. Most recently, new metals have made it possible to resurface the head of the femur (thigh bone) with good results.

Fracture (usually of the femoral neck) is the most likely complication of hip joint resurfacing. It happens in up to four per cent of the cases. Studies show fracture occurs most often in the first 100 cases done by a surgeon. Fracture rates go down as the surgeon becomes more familiar with this technique.

Causes of fracture are both patient and technique-related. Obesity, decreased bone mass, and arthritis make a difference on the patient side. Anyone with a femoral neck cyst should get a total hip replacement instead of resurfacing. Putting the implant in with too much of a tilt or twist can also result in fracture.

Women seem to have a higher risk of fracture after hip joint resurfacing. The reason for this remains unknown at this time. Short-term results of hip joint resurfacing are good to excellent. Long-term studies aren’t available yet. Total hip replacement may be needed by patient who have a fracture after resurfacing.