Feasibility study to evaluate the clinical outcome of the Scorpio knee prosthesis following THE LAZIRUSH CONCEPT

The popularity of total knee arthroplasty (TKA) can be attributed to its
success in relieving pain, correcting deformity, and improving function for
patients with arthritic knees. As the population in the industrialized world
grows older, it is likely that more patients will seek knee replacement as a
mean of treating painful arthritic knees. Because of the high volume and cost
of TKA*s, these procedures are often targeted for cost reduction. One of the
main elements to effectively reduce the cost of knee arthroplasty, besides a
reduction of the costs of the prostheses and minimizing peri-operative
complications, is a decrease in length of hospital stay. It was shown that
average length-of-stay reductions have a significant effect on total cost of
knee arthroplasty [1,2,3,4]. The length of hospital stay for total knee
arthroplasty seems to be influenced by several factors. Dutton et al. found a
significantly shorter inpatient stay for patients who underwent
computer-assisted minimally invasive arthroplasty compared with patients who
underwent conventional TKA without an increase in the rate of short-term
complications [5]. A multimodal perioperative anaesthetic and pain management
strategy can also reduce the length of stay [6]. The review of Coudeyre et al.
found that a preoperative rehabilitation program, comprising at least physical
therapy and education, contributed to reduced hospital length [7]. Joint
replacement programs [1, 8,9], accelerated rehabilitation [10,11] and clinical
pathways have consistently been linked to shorter hospitalization without
increased complication rates. These programs incorporate several elements, for
example pre-operative education, peri- and post-operative pain management,
early and aggressive rehabilitation, proactive discharge planning.
A new program aiming to improve a fast comfortable recovery after total knee
replacement is called the Lazirush concept or the *2-day Knee*. By not using
pain pumps, drains or catheters the risk for infection will be minimized. Also
during the operation there will not be no tourniquet used which will reduce
bleedings and swelling after surgery thereby leading to a possible faster
activation of muscle function and performance.
Therefore the goal of this study to evaluate if the patients treated the
Lazirush concept will have better functional scores early postoperative (<6
weeks) and a shorter hospital stay compared to the traditional care methodology
the Joint Care concept.

To evaluate the early and late postoperative results measured by the KSS and
ROM of the Scorpio knee prosthesis following the Lazirush concept and compare
this with a matched group of patients undergoing a Scorpio knee prosthesis
following the Joint Care concept.

50 patients of the Medical Center Alkmaar will be recruted.

Patients willing to participate in this study, and a signed informed consent
will be randomly assigned to Group A or Group B.

Group A: 25 patients with TKA, managed and treated by the traditional concept
of Joint Care
Group B: 25 patients with TKA, managed and treated by the Lazirush "concept"

The following FUs are implemented:

Pre-op
Prior to discharge
Diary Day 1 / 7
Week 2
Week 6
Week 12

The following questionnaire will be assessed at pre-op, week 2.6 and 12:
Koos, SF12

All patients will get a total knee replacement surgery using the lazirush
concept or the concept of joint care.

The study involves the routine assessment of a knee arthroplasty procedure. The
device has been CE marked and will be used according to its labelling.
Assessment involves questionnaires, patient and investigator assessments, and
routine radiographs. The information collected will be kept confidential and
will comply with the Declaration of Helsinki.

At 6 weeks one additional long leg X-ray will be made in order to assess
accurately the post-operative mechanical axis alignment. The additional
radiation dose will be limited by combining the routine AP/LAT X-ray with the
long leg X-ray for which only an additional AP-pelvis and AP-ankle X-ray is
needed. The effective radiation dose for these two images is 3 µSv [12]. The
additional annual radiation dose is negligible if the natural annual exposure
of 2 mSv is considered and will do the patient no harm [13]. The International
Commission on Radiological Protection categorizes the corresponding level of
risk qualitative due to radiation as *trivial* with a quantitative risk of
about one in a million or less. The required level of benefit should be related
to *only increase knowledge*.
(http://ec.europa.eu/energy/nuclear/radioprotection/publication/099_en.htm)