Quantifying the interactions and effects of joint function, pathology and pain in end-stage OA to understand why Total Knee Replacement (TKR) outcomes vary

This course is a 3.5 year PhD Programme.

Despite a 20% dissatisfaction rate, Total Knee Replacement (TKR) patients are generally treated as a homogenous group. Multifactorial data is required to improve diagnosis of OA and stratify patients in order to predict outcomes and better target therapeutic and surgical interventions. The Centre enables multiple protocol studies on the same subject. Our studies differ from existing patient-based stratification studies for OA:
(i) we exploit novel decision making tools (Principal Component Analysis/uncertain reasoning) linking biology, biomechanical and clinical data to discover which factor combinations predict poor outcomes, why, and how this can be remedied by targeting treatments;
(ii) we combine multifactorial data for each patient, pre-to-post intervention. These will lead to patient stratification and effective targeting of management.

Approach: Biomechanics will be quantified for Activities of Daily Living (ADL) and other functional measures for patients (pre- and post-TKR) and for healthy volunteers. Patient subjects may also be assessed pre- and post-TKR, using joint imaging combined with motion capture.

Analysis: Biomechanics, patients reported scores, physiotherapy and patient history, pre-surgery MRI to define OA markers, X-ray, post-surgery low-dose CT to quantify implant alignment (if available), and combined motion analysis, fluoroscopy and image registration, EMG and force plate data. Long leg X-rays will define knee obliquity/leg alignment. TKR CAD models acquired with industry for image registration/fluoroscopy, may be used to define implant kinematics.

Outputs: Biomechanical changes will be assessed (Visual3D). Knee translations/rotations and contact locations quantified using image registration/fluoroscopy. Muscle activations (EMG), marker and force plate data will drive joint loading models (OpenSIM).
This will provide gait, stair ascent/descent, sit-to-stand/stand-to-sit data for the Cardiff Classifier to identify whether biomechanical indicators of recovery are evident pre-surgery, and to quantify knee obliquity/mechanical axes/implant orientation pre-to-post-TKR.

TKR patient stratification and outcome measures will be based on biomechanics, pain, clinical and psychosocial data for late-stage knee OA patients.

Interdisciplinary aspects: This is an interdisciplinary project between the Schools of Engineering, Psychology, Healthcare and Cardiff and Vale Orthopaedic Centre. The project gives us an opportunity to link clinical and possibly biological biomarkers to longitudinal changes in patient biomechanics.

This project is part of the Arthritis Research UK Biomechanics and Bioengineering Centre of Excellence http://www.cardiff.ac.uk/arcbbc/index.html

Candidates should hold or expect to gain a first class or a good 2.1 MEng degree and/or an appropriate Master’s level qualification (or their equivalent) in a relevant subject area.

Informal enquiries may be directed to Professor Cathy Holt, [Email Address Removed] .