03.01.2018 change 03.01.2018

Innovative device helpful in hip replacement surgery

Photo: Fotolia Photo: Fotolia

An innovative device for measuring the change of the femur position during hip replacement surgery has been built by scientists from Lodz University of Technology. Its use shortens the time of surgery and gives better chance that patients after surgery will not have problems with walking.

The invention has been patented by a team of scientists led by Prof. Leszek Podsędkowski from the Institute of Machine Tools and Production Engineering, Lodz University of Technology. Prof. Podsędkowski emphasised that hip replacement surgery is an almost routine procedure in the world - around 2 million such procedures are carried out every year.

"However, the problem of accurately measuring the change in leg length, which occurs as a result of hip replacement, is still not completely solved. After hip replacement, the leg simply can sometimes be a little longer or shorter. This problem was reported to us by the surgeons themselves, specifically Dr. Michał Panasiuk, MD, a practitioner in the field of hip arthroplasty, who cooperated with us on creating the device" - described the scientist in an interview with PAP.

Statistics show that about 10 percent patients after surgery have a difference in the length of the leg causing various types of problems.

"It all depends on the experience of the surgeon, but our goal is the situation in which it is a much smaller percentage, or even all patients have a guarantee that this error will be 3 mm at most, i.e. imperceptible" - explained Prof. Podsędkowski.

The tools used so far make the procedure more difficult and extend the operation time. Scientists from Łódź have developed an innovative, disposable device that allows to make a measurement in a very short time. The device is 10 cm long, weighs approx. 40 g, is fully electronic, with a digital display.

"The innovation of this device lies in the fact that it is very accurate, and it can be disassembled. It allows for measurement with an accuracy of less than 1 mm, which is not available in other devices. It is based only on parts that are mounted into the patient, in the surgical wound, and as a result it does not interfere with the surgical procedure.. It is very simple and easy to use" - explained the inventor.

In the beginning of the procedure, after exposing the bones on the hip joint, the surgeon mounts special markers on the hip bone and on the femur and attaches the measuring arm. It measures the initial parameters before the surgery. Then it is removed and the surgeon implants the prosthesis. Later he makes the second measurement, which shows the change in this length in relation to the first measurement. If the change is small, the surgery ends, if the measurement result is unsatisfactory, the surgeon changes the parts of the hip replacement - the head or the neck - so that they fit better.

According to Prof. Podsędkowski this innovative device will not only shorten the time of surgery, but also give greater guarantees that patients after surgery will not have problems with walking. Another advantage of the device built in Łódź is the price, because the cost of this solution must be low enough that it does not significantly change the cost of the procedure.

"Our device is significantly cheaper than the devices on the market because our goal is a disposable device available to all patients. It is 10 times cheaper than competitive methods" - he emphasised.

The solution of Łódź engineers is protected by a patent not only in Poland, but also in the EU, in the United States and in Japan. The device has positive opinions of the Polish Society of Orthopaedics and Traumatology.

"I hope that in half a year, maybe a year, it will be mass produced and delivered to patients. But it all depends on the strategy of the future manufacturer" - added Prof. Podsędkowski. (PAP)

PAP - Science in Poland

author: Kamil Szubański

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