Fast Track Recovery with Bioheat Transfer in Knee Revision-prosthesis

This trial is meant to verify a new medical method (computer controlled bioheat
transfer) to reduce pain and swelling and optimize early mobilisation following
knee replacement revision surgeries. Most likely because of greater soft tissue
trauma functional outcome after revision knee arthroplasty is not that good as
after primary knee arthroplasty. [1-5] To reduce the inflammatory reaction
caused by the soft tissue trauma during the operation, cryotherapy is used
postoperatively.

At the Department of Orthopaedics Surgery OLVG Amsterdam, currently, cold packs
(koud en warm pak, ENRAF-NONIUS B.V. P.O. Box 12080 3004 GB Rotterdam, the
Netherlands; CE 65.0103002.12, LA 3448209) are used for cryo-therapy to reduce
postoperative pain and swelling. The cold packs are used twice a day for twenty
minutes each time. Cooling the operative wound with this method shows positive
effects, but the method offers a great room for improvement: at the beginning
of the treatment with cool packs the temperature is too cold (sometimes below
zero degrees - depending on the temperature of the freezer, which could well be
-18 degrees), with the risk to complications and little comfort to the patient
and after a short time the packs are getting too warm (body temperature),
because of which no long and deep cooling is possible.
A new approach to attain better results is a new computer-controlled bioheat
transfer platform, named cTreatment. The class 2a medical device provides a
controlled, continuous, stable and predefined temperature at the affected site
(the operated knee in this trial) and guaranties an optimal tissue temperature
drop, not only superficially but also in depth. Optimizing the tissue
temperatures and thereby lowering the postoperative inflammatory reaction, both
superficial as in depth, over a longer period is expected to reduce swelling
and pain, whereby patient's postoperative mobilization can be started earlier
and be done more efficiently, leading to a reduction of the length of
hospitalization.
The cTreatment Technology server based Platform has embedded the complex
phenomena of Bio Heat Transfer to control the parameters within the
thermodynamic model. Bio Heat Transfer is a dynamic process that analyses
transport of heat by conduction, convection and radiation, as well as by
temperature dependent, spatially heterogeneous blood perfusion in living
organisms with conventional mathematical models (Pennes' equation, Che and
Holmes new bioheat equation) and numerical techniques (continuum bio-heat
transfer in three dimensional anatomical structures). From a thermal point of
view, biological systems consist of a complex network of blood vessels which
convect heat and are embedded in tissue. The tissue is inhomogeneous and at
times anisotropic with complex thermal properties. It also produces heat as
part of the life and of pathological (e.g. inflammation) metabolism. All these
aspects of a living organism make mathematical models of heat transfer complex.
The standardized, computer controlled cTreatment® protocols incorporate
thermodynamic bio heat transfer with the body, based upon scientific and
reproducible protocols. Through indication specific protocols and by using
active feedback, it enhances the positive healing effects of inflammatory
processes and reduces the destructive effects of inflammation, allowing the
medical professional more complete and direct control of the recovery process.
cTreatment has both triggering and synergetic effects on most of the
physiological parameters of inflammation and trauma:

In the Department of Orthopaedic Surgery of the OLVG currently postoperative
hospitalization after revision of a knee-prosthesis takes 14 to 18 days on
average. It is an international aim to reduce the duration of postoperative
hospitalization (reduction of costs). Since optimizing in prosthetic design is
rarely possible as it*s already that well engineered, it*s worthwhile to focus
on postoperative soft tissue management in further investigations.
In pursuance of previous experience, cryotherapy influences patients*
postoperative mobilisation positively. [6-8]

The aim of the study is to compare cTreatment with the standard cooling
protocol (cool packs) used at the Department of Orthopaedics Surgery OLVG in
patients with revision procedures after a previous primary total knee
arthroplasty. We expect, that patients treated with cTreatment need less pain
medication, show reduced swelling and a quicker recovery to full flexion
compared with patients treated with conventional superficial cryotherapy with
cold packs.
This pilot study will be done in cooperation with the Department of Orthopaedic
Surgery, Medical University of Graz.

To compare the methods patients will be divided into two groups, a therapy
group (receiving cTreatment) and a control group (receiving standard
cryotherapy). Patients will be evaluated pre- and postoperatively, wherefore
the following data are collected: the knee flexion, swelling (in centimetres),
laboratory parameters (standard parameters) clinical evaluation scores and
psychological parameters (using standardised questionnaires) as well as the
AAOS discharge criteria.
The collected data shall be analysed to show any difference between cTreatment
(computer controlled bioheat transfer) and the standard short period
superficial cooling therapy following implantation of a revision knee
endoprostheses.

Multi center, double-blind randomized placebo-controlled pilot trail.

Study centers:
OLVG Amstedam
Medical University of Graz

Duration: 12 Month

Our hypothesis is that c-Treatment improves range of motion, reduces
postoperative swelling of the knee and that pain scores are lower. We also
expect that the length of stay will be reduced. Because the contact temperature
is never below 8 degrees Celsius there is no risk for cryo-lesions or burn
lesions. There is also no higher risk for thromboses, infections or other
adverse events. Since the first use of cTreatment no adverse events were
reported, besides a few blisters, which could not be directly related to the
use of cTreatment. The 2 patients in whom they occurred had also used ice-bags
during their hospital stay, which are a known risk to frostbite.
During three pilot studies (total 59 patients) no adverse events were reported.
In one of these studies cTreatment was even applied during 12 hours of
continuous use on 10 patients. Furthermore in the recent comparative cohort
trial in the AMC in Amsterdam no adverse events were reported on the 31
patients who received cTreatment for primary total knee arthroplasty.