POSTER ABSTRACTS - ISAKOS

Dual Energy X- ray Absorptiometry (DXA) with a
bone densitometer specially designed for
measurements on small animals (PIXIMUS). At 6
weeks after the operation 15 rats from each group
were killed and the healing fractures were
mechanically tested in three-point cantilever
bending.
Results: The bone mineral density (BMD) at the
fracture site were significantly lower in the
parecoxib group compared to the control group
after both 2, 3 and 6 weeks, the difference was
decreasing with time. There was no significant
differences in mechanical properties 6 weeks after
fracture.
Conclusions: Parecoxib decreased BMD at the
fracture site for 6 weeks after fracture. Mechanical
strenght after 6 weeks were not affected.
E-poster w/ Standard #179
The Role of Radiofrequency Microdebridement
in Meniscus Surgery: A Study in a Sheep Model
Wolf Petersen, Muenster, GERMANY, Presenter
Thore Zantop, Pittsburgh, PA USA
Andre Weimann, Kiel, GERMANY
Thomas Fuchs, Muenster, GERMANY
Richard Stange, Muenster, GERMANY
Thomas Pufe, Kiel GERMANY
Department of Trauma, Hand, and Recinstructive
Sur, Muenster, GERMANY
Purpose: Synovial abrasion and trephination have
been used successfully as neovascu-larisation
techniques to stimulate meniscus healing.
Recently, a beneficial influence of radiofrequency
microdebridement on tendinopathies has been
described. Aim of the cur-rent study was to
evaluate the influence of bipolar radiofrequency
microdebridement on the healing of medial
meniscus tears in a sheep model.
Type of study: Experimental animal study.
Methods: Merino sheep underwent unilateral
medial meniscus repair using three differ-ent
techniques: trephination and suturing (group 1),
and application of radiofrequency
microdebridement and suturing (group 2). Six
weeks postopertively the angiogenic re-sponse
was evaluated by factor VIII immunostaining and
VEGF expression was analysed using an ELISA
and RT PCR.
Results: Quantitative assessment of factor VIII
immunostaining showed a significant higher
amount of blood vessels in both groups of
repaired menisci in comparison to unin-jured
menisci. There was no significant difference
between the two treatment groups. The ELISA
measurements showed that the intrameniscal
VEGF concentration was sig-nificantly elevated in
both treatment groups in comparison to
uninjured control menisci without any statistical
significant differences between both treatment
groups. From all specimen, two PCR products
were obtained: One with 526 bp corresponding to
VEGF121 and one with 658 bp corresponding to
VEGF165. In both treatment groups the bands
were much stronger than in specimen of uninjured
menisci.
Conclusion: The results of the current study
suggest that no beneficial effect can be gained by
the addition of bipolar radiofrequency to the
trephination of a torn meniscus. Additional basic
research is needed to investigate different time
duration for the energy application and the effect
of different energy settings.
E-poster w/ Standard #180
Reducing the Killer turn in Single Bundle PCL
Reconstruction: Anatomical and Extracortical
Fixation Under Cyclic Loading
Thore Zantop, Pittsburgh, PA, USA, Presenter
Andre Weimann, Kiel, GERMANY
Alexandra Wolfert, Kiel, GERMANY
Thomas Fuchs, Muenster, GERMANY
Richard Stange, Muenster, GERMANY
Wolf Petersen, Muenster GERMANY
Department of Trauma, Hand, and Reconstructive
Sur, Muenster, GERMANY
Several authors hypothesized that the abnormal
posterior tibial laxity after PCL reconstruction
could be related to thinning and permanent
elongation of the graft as it turns around the
sharp edge of the posterior tibial tunnel and being
cyclically loaded in vivo. Aim of this study is to
evaluate the influence of the so-called killer turn
on the structural properties of a soft tissue graft
using an extra-cortical and an anatomical fixation
under cyclic loading.
Grafts were fixed in a porcine tibia model using
interference screw fixation close to the joint line
and extracortical fixation with staples. Ten
reconstruction each were cyclically loaded (2000
times) between 50 and 150 N and ten were
subjected to 2000 cycles between 50 and 300 N
force. The surviving PCL reconstructions were
loaded to failure using a material testing machine.
Load and elongation were recorded continuously
using a strip chart recorder. Elongation, stiffness,
maximal load, yield load, as well as failure mode