02/27/2019 | Press

New instruments for old bones

The workshop series "Incisions and insights - medtech engineers and medical practitioners in dialogue on anatomy" continued in February 2019, focusing on "extremities and the musculoskeletal system". Live-streamed surgery and practical exercises in the operating theatre at the Institute of Clinical Anatomy and Cell Analysis gave medtech engineers the opportunity to talk with medical directors and consultants and develop new ideas for instruments and methods. One of the issues highlighted by the latest workshop was the challenge of operating on joint and bone defects in older people. In Germany alone, there are more than 17 million people over the age of 65 as a result of population ageing, which was good reason for the doctors to set the medtech engineers some homework.

"This is an invitation - let's talk! We're not here to show how good we are. We're here to highlight the deficits and difficulties that exist so that you can put forward suggestions that will make the lives of patients easier in the future." Prof. Arnulf Stenzl, Medical Director of the University Department of Urology and Head of the Inter-University Center for Medical Technologies Stuttgart-Tübingen (IZST), welcomed the medtech engineers and developers with this clear statement. Together with the host Prof. Bernhard Hirt, Medical Director of the Institute of Clinical Anatomy and Cell Analysis, he guided the participants through an afternoon filled with exciting incisions and insights.

The fifth workshop looked at the topic of "extremities and the musculoskeletal system". A number of typical cases had been prepared at the operating tables in Anatomy - osteoarthritis of the knee, a ruptured scapholunate ligament in the wrist, and knee replacement implants. As the doctors from the various fields demonstrated the procedures - and the associated challenges - the medical directors talked to the participants in attendance and those tuning in via the live stream in real time. Once again, several highly respected specialists from the University Hospital of Tübingen took part in the event, including Prof. Christian Bahrs, Senior Consultant for Traumatology and Reconstructive Surgery; Prof. Stephan Clasen, Deputy Medical Director of Diagnostic and Interventional Radiology; Prof. Adrien Daigeler, Medical Director of the BG Trauma Clinic in Tübingen for Hand, Plastic, Reconstructive and Burn Surgery; and Prof. Nikolaus Wülker, Medical Director of the Orthopaedic University Hospital Tübingen.


Custom bone levers

Osteoarthritis of the knee can be caused by the malalignment of the joints or excessive strain on the joints. The surgeons gave a live demonstration of how to adjust the axis of the knee to take the strain off the cartilage. When this operation is to be carried out, X-ray images are first used to measure the exact axial deviation and calculate the necessary realignment. In the operating theatre, the surgeon must then first carefully scrape away the soft tissue of the bone with a raspatory and move the periosteum, the membrane covering the bone, to the side to expose the operating area. The bone is levered up with a Hohmann bone lever. An "angel wing" is then used to set the angle at which the shin or thigh bone will be cut using a bone saw. Finally, the bone is reset with a plate and screws. The surgeons demonstrated very clearly that even though all the relevant parameters are determined down to the last millimetre beforehand, what really matters on the operating table is the experience and intuition of the surgeon in applying these results on the patient. That is why the consultants who spoke at this event are working towards a future where robot technology and digital navigation are used to help apply the findings from preoperative diagnostics in the operating theatre. There was a general consensus during discussions that, on the one hand, the instruments used (some of which were developed decades ago) are well-established, functional tools but, on the other hand, it would be highly desirable
to achieve a situation where bone levers and plates could be adjusted on a customised basis on the patients. Treating a torn scapholunate ligament in a patient's wrist demonstrated yet again just how vital miniaturisation and flexibility are for surgical instruments. This kind of keyhole surgery involves using instruments and a camera to operate on a tiny part of the hand that is very difficult to see - so it is vital that surgeons receive intensive training on how to use these instruments.


Stronger connections

One of the key challenges facing surgeons is the age of their patients - as patients get older, their skin gets thinner, making it more difficult to suture a wound after an operation. When osteosynthesis is performed, i.e. when bones are joined together after a fracture such as an ankle injury, the bones of elderly patients are often brittle and fragile. This means it is not always possible to apply forceps or fix screws and plates adequately. That's why instruments developed for young, healthy bones should be produced with wider contact surfaces so that pressure is not concentrated too heavily in a single area. In addition to making these kinds of demands of medtech developers, the doctors also highlighted the limits of technology during the discussion. In their view, solutions are ultimately needed that will pre-emptively protect joints and bones from the effects of osteoarthritis and osteoporosis so they can still be operated on. This also applies to knee and hip replacement implants, which instead of wearing down in the body over time, tend to loosen as the bones stop providing the necessary support.


Save the date! The dates for the next "Incisions and insights" workshop:

Intelligent permanent implants: 3 July 2019
S3martMed: Incisions and insights - international: 19 September 2019
Endoscopy, robotics in diagnostics, surgery: 5 February 2020
Torso, spine, spinal segment: 1 July 2020