Prospective follow-up of clinical efficacy of knee distraction as treatment for knee OA by use of 'ArthroSave's Knee-Reviver'.

Knee joint distraction is a surgical technique by which the two bony ends of
the knee joint are separated for a few mm for a few weeks by use of an external
distraction device. This (by the UMC Utrecht developed) treatment for severe
end stage knee osteoarthritis below the age of 65 years is clinically very
effective and results in joint tissue repair. Most importantly this treatment
can postpone the initially indicated total knee prosthesis (knee arthroplasty)
for over 5 years up to even 10 years in * of the treated patients. With that
this joint saving treatment can prevent the need for costly and less effective
prosthesis revision surgery. This makes this novel joint distraction treatment
very cost effective. However, thus far all studies have been performed with a
*proof-of-concept* (off-the-shelf) medical device designed for trauma surgery
(Stryker monotubes). Despite the clinical benefit, these monotubes are
unnecessary burdensome for patients to wear (unnecessary bulky) during the 6
weeks distraction period. Moreover, with these Stryker tubes the surgical
procedure is unnecessary complex and time consuming (too many bolt and nuts to
tighten, limited flexibility in positioning). This results in unnecessary
inconvenience for patients and surgeons. The UMC Utrecht has therefore
developed in collaboration with ArthroSave a *user-friendly* dedicated knee
joint distraction device called *the Knee-Reviver*. This device has the similar
essential mechanical properties (as part of the requirements of its CE marking)
and makes use of the same pin fixation positions as the Stryker tubes. As such
clinical outcome of treatment is considered to be equal to that of the Stryker
device. But clinical efficacy of ArthroSave*s Knee-Reviver has never been
evaluated.

To document clinical efficacy of ArthroSave*s Knee-Reviver at 1, 2 and 5 years
after distraction by:
1st: an increase in WOMAC score (pre-treatment vs. follow-up).
2nd: an increase in radiographic joint space width (pre-treatment vs.
follow-up)

Prospective uncontrolled 5 centre, 5 years follow-up study; n=75 patients, 15
patients per institute.

Knee joint distraction for the designated population is at present by the UMC
Utrecht, Maartens Kliniek, and Maastricht UMC performed in clinical practice
using the Stryker mono-tubes. Over 100 patients have been treated without
adverse events due to the mechanical properties of the device. Knee joint
distraction using ArthroSave*s Knee-Reviver has no additional risk as compared
to distraction treatment with the Stryker monotubes as this anticipated
user-friendly knee distractor uses the same bone pin positions, and has the
same mechanical characteristics (all part of the CE certification) providing
mechanically an essential similar treatment. As such similar clinical benefit
is anticipated. However, ArthroSave*s Knee-Reviver (although CE certified with
knee joint distraction for osteoarthritis as intended use) has never been
tested on humans in clinical practice. This provides a potential risk of
unforeseen, though unanticipated, complications.