Kompendium 2020 Forschung & Klinik

TOP-Studien
47
Figure 1. (A) Intraoperative picture of the medial
femoral condyle after spongialization. The size of
the defect was standardized to remove the most
degenerated cartilage areas. Macroscopic image
of the (B) MACT group at the 12-month follow-up.
were separated into three different treatment groups (SPONGIO, MATRIX,
MACT) and one control group in which the cartilage defect and the surrounding
tissue were not treated.
In the sheep of the SPONGIO group, the cartilage of the load-bearing zone of
the medial femoral condyle was removed with a standardized oval punch and
a curette. The bone was then removed to a depth of 2.5 mm using a burr with
a spherical and a cylindrical attachment. This technique is called „spongialization“
6 . Bleeding was stopped with a thin layer of fibrin glue (Figure 1A).
„To date, the curative treatment of
osteoarthritis is limited to joint
replacement surgery. However, this
entails certain surgical risks and
limited implant survival, especially
in young sportive patients.“
Stefan Toegel
The animals in the MATRIX group received the same treatment as those in the
SPONGIO group, with the difference that a hyaluronic acid matrix was applied
on top of the fibrin layer. In the MACT group, the procedure was similar to that
in the MATRIX group. The difference was that the hyaluronic acid matrix was
colonized with autologous cultured chondrocytes (1 x 10 6 cells per cm 2 ) before
implantation. The macroscopic evaluation of the cartilage regeneration was
carried out using the Brittberg Score, whereas the histological evaluation was
performed using the Mankin Score and the O’Driscoll Score.
Results
Results of the control group showed a gradual, significant deterioration of
osteoarthritis over 4 and 12 months. There was no regeneration in the defect
area, and the adjacent cartilage showed increasing degeneration both
macroscopically and histologically. In all treatment groups, the regenerated
cartilage showed a zonal structure. After 4 months, the MACT group yielded
significantly better results than the other two regeneration groups (MATRIX,
SPONGIO) regarding macroscopic and histological parameters. The SPONGIO
group showed good chondrocyte quality after 4 months, but the cartilage
surface was very uneven. The MATRIX group was dominated by the formation
of regenerated tissue, which did not correspond to hyaline cartilage.
In the course of 4 to 12 months, an improvement in all regeneration groups
was detected. In 4 out of 6 sheep of the MACT group, the regenerate filled
the full height of the 2.5 mm deep and 20x10 mm large defect (Figure 1B).
Excessive regeneration above the normal cartilage cell height was not
present in any of the animals. Safranin O staining of the regenerated mate-