An Aberdeen surgeon hopes to find out if an increasingly performed, less invasive type of hip replacement surgery may lead to hip fracture in up to two per cent of patients.
Seventy patients undergoing metal on metal (MoM) hip resurfacing at the Aberdeen Royal Infirmary will take part in a study to be carried out by orthopaedic surgeon and senior lecturer at the University of Aberdeen Paddy Ashcroft. Mr Ashcroft has been awarded a three-year project grant of more than £200,000 by leading medical research charity the Arthritis Research Campaign.
MoM hip re-surfacing now accounts for up to ten per cent of all 60,000 hip replacements performed in the UK and is usually carried out on younger, more active people.
There are two ways of performing the surgery; the recommended standard posterior approach and the alternative anterolateral approach. Although it is the recommended technique, it is thought possible that the posterior approach may result in damage to the blood supply of the hip, resulting in a delayed fracture or death of the femoral head in patient's hips up to ten weeks after the operation.
"There is uncertainty about why up to two per cent of patients have this fracture after surgery using the standard posterior approach, and I want to answer that question," said Mr Ashcroft, who uses the anterolateral technique.
"It may be to do with the quality of the patient's bone the, damage to the bone during surgery, or maybe the positioning of the implant. But it could be that this particular surgical technique damages the blood flow to the hip, leading to fracture in the first couple of months after surgery."
Mr Ashcroft moved to reassure the many thousands of people who have had their hips resurfaced. "The survival rate for hip resurfacing at ten years are excellent; between 95 and 98 per cent, and if we could reduce the small percentage of people who have this early fracture, that would be even better," he said. "If we provide evidence on the potential damage to blood supply, it may lead to a change of clinical practice, using the alternative surgical approach."
Seventy patients about to undergo hip resurfacing will have the blood in their femoral heads measured before surgery and then eight to ten weeks after surgery, when they are at the highest risk of fracture. Mr Ashcroft and his team will use state-of-the-art scanning techniques called positron emission tomography (PET) based at the Scottish PET Centre in Aberdeen to measure blood flow in the bone.