A special seminar was given by Dr Vlado Stankovski from the University Medical Centre of the University of Ljubljana on the topic of "Computer System for Estimate of Biomechanical Parameters of the Hip Joint".
The computer system developed at the University of Ljubljana Medical Centre can estimate the geometrical parameters of the human pelvis and femur and then calculate the stress distribution in the hip articular surface. The code was developed using Java and basic data about the patients, as well as digitised profiles of standard anterior-posterior radiographies are used as input to the computer system.
The system can automatically calculate some important reference points, distances and angles that define the geometry of the body and the femur. By calculating these parameters, they system calculates and visualises the hip joint reaction force and the stress distribution acting on the hip joint is based on an existing three-dimensional model. Additionally, the system allows for visualisation of the danger in the stress distribution for given changes in the geometry of the joint.
The performance of the system was evaluated by calculating the geometrical parameters of the pelvis and femur and the maximum stress in the joint for 81 patients (37 male and 44 female) that were operated on for acute mechanical fracture of the neck of the femur by implantation of the hip endoprosthesis. It was found that the calculated maximum stress in the case of the healthy non-operated hip is on average 20% greater in the female population than in the male population, which is a statistically significant difference. These results suggest that the incidence of arthrosis is greater in females than in males.
The system described by Vlado can be used to determine the contact stress distribution in the joint based on standard Anterio-posterior medigraphics. The system can be applied in the clinical practice to predict optimal stress distribution for different types of operative interventions in the hip and to analyse the short and long term outcomes of the treatment of various hip conditions.
The system represents a major advance in biomedical research.
Wessex Institute