Made-to-measure solutions for enhancing prostheses of amputated legs

TECNALIA Corporación Tecnológica and the Valencia Institute for Biomechanics (IBV) have designed made-to-measure solutions to improve adaptation to replacements for amputated legs – the prime objective of the new health biomaterials project, FABIO, financed by the Ministry of Industry, Trade and Tourism.

The FABIO project aims for the total integration of the chain of design and manufacture of implants and necessary elements for enhancing the quality of life of patients. To this end, the project takes into account the process from the acquisition of data of the patient to the moment of surgery and the limb implant.

FABIO aims to achieve a process that is viable for manufacturers of these products, both for the quality of the results as well as for their functionality and financial and time costs. Thus, these advances could arrive on the market in three or four years.

In this project, the TECNALIA Health Unit focuses on the study of diverse biomaterials for the direct obtaining of health products through rapid manufacture technologies. What is involved is enhancing current materials at structural, mechanical, physical, functional and biocompatible levels in such a way that the materials developed within the project have properties equivalent to the natural materials of the human body. The materials obtained are characterised in the laboratory, during manufacture and in service.

The project, began in 2007, has already achieved the manufacture and evaluation of a new product. Concretely, what is involved is the possibility of designing a prosthesis socket for a patient with an amputated leg.

An amputation is an acquired condition the outcome of which is the loss of a limb and the cause usually being an injury, a disease or as a consequence of a surgical operation. More concretely, for amputations of the lower limb (85% of all amputations undertaken), the main cause is a peripheral vascular disease, the second cause being a break in the bone (10-12 % of all lower limb amputations).

In western developed countries the rate of amputations of lower limbs is 17.1 amputations per 100,000 inhabitants – in Spain alone 5,000 such amputations are carried out each year.

Currently, the number of persons with amputations of lower limbs is steadily increasing, due to the ageing of the population and the increase of peripheral vascular disease.

Amputations moreover mean a loss in mobility, a great psychological trauma for the patient who, besides, may fear that the amputation reduces acceptation by others. Apart from this, the loss of part of the body changes the self-image of the patient and his or her self-esteem.

Partners in the project have stated that they have managed to achieve "a personalised computer design for the socket that joins the prosthesis to the leg of the patient". This design is undertaken by a laser scanning of the geometry of the patient´s stump. The result of the scanner enables the manufacturing of the socket with biocompatible resin and which adjusts perfectly to the stump.

This personalised socket has satisfactorily overcome the adjustment and operational trials and which will shortly serve for the evaluation of its mechanical resistance according to current norms.

In this sense, the first development undertaken by the FABIO Project could enhance the process of rehabilitation and patient care, amongst other aspects because costs and times are reduced, given that it is not necessary to make a plaster mould nor the final adjustments of fitting of the patient´s limb, thus reducing the number of required visits to the orthopaedic surgeon.

Source: Elhuyar Fundazioa