Re-vascularisation of the femoral head in the initial phase of Perthes disease
Dr David Kieser
University of Otago, Christchurch
What is the problem and who does it affect?
An estimated 50 children each year in New Zealand are affected by the life-changing bone disorder, Perthes disease. It occurs as a result of avascular necrosis on the upper thigh bone – known as the femoral head – which essentially means there is insufficient blood supply which results in degradation and death of the femoral head.
Males are four times more likely to develop Perthes disease than females. The onset of symptoms usually occurs at around 4 to 10 years-of-age.
The exact cause of Perthes is still unknown, however, the issues associated with the condition are well-documented. It can cause great pain in children, resulting in a limp, reduced range of movement and even early-onset arthritis.
Children with Perthes are often required to undergo arthroplasty – surgery to replace or reconstruct the joints. The long-term outcomes for such an intervention can significantly reduce the quality of life for those living with Perthes disease. Alternative means of treatment are important not just for New Zealand patients, but those worldwide.
What is this project hoping to achieve?
The issue is that the main blood supply to the femoral head is arrested. Dr Kieser and his team note that the blood supply next to the growth plate is abundant and hence if they can reroute some of this bountiful blood supply to the femoral head then this could assist in bone tissue formation.
Dr Kieser and his colleagues propose to use a preclinical model to re-vascularise (provide with a blood supply) the femoral head. They will use stents, essentially tubes which will transport vascular endothelial growth factor (VEGF) to the femoral head. VEGF is known to create new vascular channels, also known as blood vessels. This, theoretically, should restore sufficient blood supply to the femoral head, halting the process of bone tissue degradation.
The hope is that this research will lead to a paradigm shift in the management of this condition. The desired outcome is that open surgical procedures will no longer be required and less invasive stenting will become best practice.