POSTER ABSTRACTS - ISAKOS

econstruction of the MPFL, which has been
successful, but is not without complications.
E-poster #609
Long-term Collagen Fiber Alterations in the
Patellar Tendon Following Harvest of its
Central Third
Michael Svensson, Trollhattan, SWEDEN,
Presenter
Juri Toomas Kartus, Trollhttan, SWEDEN
Lars Rostgard, Trollhttan, SWEDEN
Eva Blomen, Stockholm, SWEDEN
Kjell Hultenby, Stockholm, SWEDEN
Jon Karlsson, Goteborg, SWEDEN
Tomas Movin Stockholm SWEDEN
NÄL-Hospital, Trollhattan, SWEDEN
Introduction: The aim of the study was to evaluate
the ultrastructure of the central and peripheral
parts of the patellar tendon six years after
harvesting its central third.
Methods: Thirteen consecutive patients, who had
undergone anterior cruciate ligament (ACL)
reconstruction using a central third patellar
tendon autograft were included in the study.
Biopsies were obtained both from the central and
lateral third of the patellar tendon under ultrasound
guidance using a 1.2 mm needle at median
71 (68-73) months after the index procedure. Ten
open biopsies from asymptomatic patellar
tendons obtained during ACL reconstruction
served as controls. The sections were immediately
fixed and prepared for transmission electron
microscopy. Longitudinal sections served for
morphological evaluation and the fiber thickness
were measured on the transversal sections. A
minimum of 100 fibres were analysed in each
specimen and grouped into five fibre size classes.
Results: All controls were found to have a
compact extracellular matrix (ECM) with regular
oriented collagen fibres. Lateral biopsies
displayed a more heterogeneous ECM. In 3 out of
13 specimen the ECM was different compared to
controls. Central biopsies displayed an even more
heterogeneous ECM. Eight out of 13 specimens
were judged as influenced. The fibre diameter
distribution among the controls displayed the
most heterogeneous pattern and all fibre sizes
were present. This was also found in the lateral
areas, however the two smallest fibres sizes (0-30
nm and 31-60 nm) were more dominant in the
lateral biopsies (88.4%) compared to controls
(72.5%). In the central biopsies, only three fibre
sizes were found and 31-60 nm was found to be
the most dominant class.
Conclusion: Six years after harvesting its central
third the patellar tendon revealed a tendon-like
repair tissue with an immature matrix with
alterations in ultrastructural morphology and
relative fiber diameter distribution
E-poster #610
One Year Results with a New Tibial Aperture
Fixation Device in Soft Tissue ACL
Reconstruction
Matthias Klepsch, Munich, GERMANY, Presenter
Ulrich Nieper, Munich, GERMANY
Tomas Buchhorn, Munich, GERMANY
Center for Sports Medicine, Orthozentrum
Muenchen, Muenchen, GERMANY
Background: Clinical experience and one year
results with the RetroscrewÃ’ - a new device for
tibial aperture fixation of soft tissue grafts in acl
reconstruction - are to be reported.
Material and Method: In Fifty-two patients the
Retroscrew system was used for tibial fixation of a
quadrupled hamstring graft in acl reconstruction.
The screw diameter was chosen dependent on
bone stock quality, either the same diameter or
one millimeter larger than the diameter of the
tibial drill hole. Intraarticular positioning of the
Retroscrew was anterior of the tibial tunnel. A
bioabsorbable interference screw was used for
femoral fixation of the graft. All patients were
evaluated with preoperative and postoperative
examination and x-rays. Follow up was after six
and twelve weeks, six month and one year. Final
follow up IKDC subjective evaluation, final follow
up IKDC objective evaluation and Tegner activity
score were performed in all patients.
Results: The average KT-1000 side difference was
2,8 mm (1-5 mm) after six weeks and 3,2 mm (1-6
mm) after 12 weeks. After six month and one year
the side difference was 3,5 mm (1-7 mm)
respectively 4,1 mm (1-7 mm). X-rays after 12
weeks and one year demonstrated no tibial tunnel
widening or other abnormal radiologic changes.
In 8 patients (15%) the tibial fixation method had
to be changed intraoperativley due to different
reasons. In 3 patients the Retroscrew did not grib
the tibial bone and could not be inserted into the
tibial tunnel. In 5 patients the screw with the fiber
wire got caught in the Hoffa fat pad. In all cases a
bioabsorbable tibial interference screw was
inserted from anterograd. In 2 patients we