Anglia Ruskin University

PhD research student: Ms Franziska Reisse.
Supervisory team: Dr Rajshree Mootanah (ARU), Dr Howard Hillstrom (HSS), Dr Rob Walker (ARU), Professor John Dowell (MEHT).
Funding body: The Chelmsford Medical Education and Research Trust

Osteoarthritis (OA) is a debilitating degenerative disease of all the tissues within the joints and often leads to significant pain, loss of joint function and is the leading cause of physical disability in the elderly. OA is problematic in the major load bearing joints (hip and knee) and can lead to significant loss of mobility and quality of life. There is an increasing number of the younger population experiencing knee OA (Dunlop et al., 2003). These patients are not well-served by joint replacement and orthopaedic surgeons will often delay joint replacement in such patients due to concerns over short prosthesis survival. HTO, a more conservative and less invasive surgery, allows preservation of bone stock and soft tissue structures, thereby 'buying time' for the more invasive TKA if needed later in life. There is no known cure for OA and current therapeutic approaches cannot arrest disease progression. Age and obesity are both strong predictors of the development and progression of OA (Petersson et al., 2002). Radiographic studies of US and European populations show that 14.1% of men and 22.8% of women over 45 years of age show symptoms of knee OA (Valkenburg, 1980). The reported total cost of OA on the UK economy is estimated at 1% of annual gross national product and $185.5 billion annually in the United States (Mathers, 2006).

Lower extremity malalignment and corresponding overloading of specific regions within the joint have been associated with knee OA and are considered to be a component of the disease onset and progression (Andriacchi et al., 2000; Sharma et al., 2001; Woo et al., 1992). Knee OA is postulated to present excessive stress to the cartilage matrix and tissues of the joint respond to stress with both biomechanical and biochemical events that leads to a cascading cycle of degeneration imposing disease progression. High tibial osteotomy (HTO) is a commonly performed realignment surgery and aim at relieving pain and restoring high-level function in active patients by re-aligning the lower limb to relieve damaged tissues from excessive contact stresses.

The aim of this study is to carry out a computational study by finite element method to investigate how different surgical techniques influence knee joint contact stresses. We anticipate that results of this study will help understand how the progression of osteoarthritis can be delayed.