Valid data with Bodytronic

Modern measurement technology not only helps with the provision of medical aids that fit perfectly, it is also a reliable tool for conducting studies. At Rostock University Hospital in Germany, the Bodytronic 600 measurement system was used to help assess the influence of medical compression stockings on post-operative leg swelling after knee arthroscopy.1

life: How did you, as a sports orthopedist, come in contact with digital measurement technology?

Prof. Dr. med. habil. Thomas Tischer:
At this university, it’s our constant mission to test and improve existing methods and develop new methods as well. The starting point for my work with digital measurement technology was the constantly recurring discussion whether compression is effective after arthroscopic procedures. We’ve been focusing on the question whether it’s actually needed for the prevention of thrombosis or whether the thrombosis risk can be resolved with medication. However, we asked ourselves what would happen with post-operative swelling if we did without compression. To answer this, we needed appropriate measurement technology.

Why did you decide to go with the Bodytronic 600?

Prof. Tischer: Using the 3D body scanner is very easy, quick and cost-effective. It’s also completely risk-free. In a separate study2, we were able to show that measurements using the Bodytronic 600 are very accurate and highly reliable. Water plethysmography would be too complicated. Plus, the Bodytronic 600 allows you to determine volumes and circumferences at the same time. Circumferences and volumes can also be measured reliably with magnetic resonance imaging (MRI). But this process is time-consuming, expensive and cannot be used with every patient. And even though computer tomography (CT) does provide accurate data, this method uses X-rays, so it’s out of the question for us.

Could you please briefly explain the design of the study?

Prof. Tischer: Patients who needed a simple outpatient knee arthroscopy, such as for meniscus damage, were randomized into two groups. For 24 hours after surgery, both groups received compression bandaging as well as low-molecular-weight heparin. Of the 19 patients included in the study, 11 patients wore medical compression stockings with compression class 2 (VenoTrain soft) for 10 days, the 8 patients from the control group stopped receiving compression. Measurements using the Bodytronic 600 were taken before surgery as well as on the first, fourth and tenth day after surgery. This was done to check how post-operative swelling of the legs develops with and without compression stockings. In addition, we asked the patients about their pain using the visual analog scale.

What were the results of the study?

Prof. Tischer: When comparing the two groups on the tenth day, we were able to identify significant differences in circumference in the middle of the thigh and at the knee based on the measurements taken with Bodytronic. In the group wearing medical compression stockings (MCS), the volume reduced by 1.35 percent. while the volume in the group without MCS increased by 0.79 percent. As early as the fourth day, we were able to observe a significant trend in the circumferences at the knee and the middle of the lower leg as well as in thigh volume. Patients wearing compression stockings tended to feel subjectively better and. The pain in the group with compression stockings was also lower, but the difference was not statistically significant. The result of the study was that post-operative swelling of the extremities can be substantially reduced when compression stockings are worn early. This can improve the subsequent recovery process. Ideally, compression stockings should be worn for three to ten days. We will definitely recommend this to our patients here at Rostock University Hospital. And whether it’s positive for thrombosis prevention or not: swelling can be reduced, which boosts recovery.

Were you surprised by the results?

Prof. Tischer: We really didn’t necessarily expect to see such significant differences with such small arthroscopic interventions. It proves that compression stockings have a beneficial effect even after minor surgery. I’m sure that the results would have been even more clear if the control group hadn’t received compression bandaging on the first day after surgery. But it has become standard practice pretty much everywhere to bandage the patient once after a minimally invasive procedure, and we wanted to compare our study with the standard case.

Do you think you may use the Bodytronic 600 for other scientific
projects as well?

Prof. Tischer: We are currently using it in another study. But since the evaluation is currently in progress, I can’t tell you anything. I’m quite sure that there are many other interesting questions that can be answered by using digital measurement technology. But some projects simply require cross-sectional imaging like an MRI, where the researcher needs to know what exactly is going on in the subcutaneous tissue, for example. But when it’s all about volume and circumference, the Bodytronic measurement technology a really
great tool.

1 Tischer et al: Impact of compression stockings on leg swelling after arthroscopy – a prospective randomised pilot study. https://doi.org/10.1186/s12891-019-2540-1
2 Tischer et al: Measuring lower limb circumference and volume – introduction of a novel optical 3D volumetric measurement system. https://doi.org/10.1515/bmt-2018-0100 (2019)

Images: Andreas Wetzel, Prof. Dr. Thomas Tischer, Bauerfeind