Pre-operative Prediction of Soft Tissue Balancing in Knee Arthoplasty

The definition of the body joints: ball socket (hip) and hinge (knee and ankle)

A 2011 survey made over 18 developed high income countries reported that over 1.3 million total knee replacements are performed every year world-wide.  Since then these number have increased, because of the ageing of the population.  While only a few percent of the patients experience problems so severe to face a new operation, between 20% and 40% depending of the studies report some functional limitation in their daily life due to the implant, so severe that are unhappy of the surgical outcome.

This paper summarises the first of part of the work done by the group of named authors over three years, aimed to the development of a personalised planning of the total knee replacement surgery that ensures the best possible functional outcome.  In this first part we conduct a study that could be impossible in physical patients, because it would need we repeat the same operation on them many times, which is impossible.  But a virtual patient can be re-operated as many times as we need; using a fully validated computer model we were able to show how even small differences in the way the surgery is formed can modify the balance of the tissues wrapping the knee, producing major or minor functional limitations.

Viceconti, M., Ascani, D., MazzĂ , C. (2019), “Pre-operative Prediction of Soft Tissue Balancing in Knee Arthoplasty Part 1: Effect of Surgical Parameters During Level Walking”, Journal of Orthopaedic Research, URL:,