The study, which was led from Lund University in Sweden, is a collaboration with researchers from Lithuania, Germany and China.
The Nordic region has the highest incidence of osteoporosis, a disease that makes bone prone to fracture. Age is one of the most important risk factors and Sweden ranks highest in terms of longevity. It is estimated that around 200 million people globally suffer from this silent disease and in Sweden alone about 124,000 osteoporosis-related fractures occur every year.
“If you have reduced bone quality, due to osteoporosis, you have not only an increased risk of fracture but also an increased risk of implant failure, if the fracture needs an operation. Screws may become loose or cut through the weakened bone tissue. Up to seven per cent of patients with hip fractures undergo additional surgery, which significantly increases the risk of serious complications among an already frail patient group,” says Magnus Tägil, professor of orthopaedics at Lund University and consultant at Skåne University Hospital.
Together with Deepak Raina, associate professor and researcher in experimental orthopaedics at Lund University, he has led the research study, which involves osteoporosis patients with hip fractures. Instead of conventional surgery using only screws and metal plates, these patients, in addition, received a ceramic bone substitute injection around the orthopaedic implant. The material, hydroxyapatite, is a natural component, in bone tissue and in osteoporosis, the resorption of hydroxyapatite increases.
“Our material solidifies within minutes, and immediately improves the strength of the bone anchorache. In a second step, the patient is given an injection of a drug, a bisphosphonate, that finds its way via the bloodstream to the bone mineral, where it binds and activates new bone formation around the implant,” says Deepak Raina.
Bisphosphonates are a group of drugs that are established and widely used in the prevention and treatment of osteoporotic fractures. They slow the breakdown of bone and reduce the risk of fractures. The study showed that it is important to apply the drug early – preferably three to seven days after the operation.
“Hydroxyapatite and bisphosphonate are both well-established and approved for human use. What we have contributed with is the combination of the two. The material gets ignited and activated, and the osteoporosis patient can start forming new living bone tissue around the implant,” says Deepak Raina.
Six months after the operation, the patients underwent a DEXA scan, which showed that bone tissue had increased by ten per cent around the screw head compared with the control group. DEXA stands for dual-energy X-ray absorptiometry and involves the measurement of bone density using an X-ray based method.
The researchers have carried out experimental studies on rats and a small comparative randomized proof of concept clinical study on patients. The next step is therefore to conduct a larger fracture study on osteoporosis patients in Sweden, and a spinal fracture study in Germany. They think it could be possible to show that the new method is better than the current treatment, not only in terms of quality of life and reduced risk of additional surgery, but also from a health economics perspective.
“All patients who sustain one of the four osteoporosis fractures – shoulder, wrist, hip and vertebra – could benefit from the improved implant anchoring,” concludes Magnus Tägil.
