POSTER ABSTRACTS - ISAKOS

INTRODUCTION: In 4-bundle hamstring anterior
cruciate ligament reconstruction, femoral fixation
can be performed with either EndoButton® or
interference screw fixation, which can further be
augmented with EndoPearl®.
PURPOSE: The purpose of the present study was
to perform a prospective, randomized clinical
comparison of two methods of femoral fixation in
hamstring ACL reconstruction. The hypothesis of
this study is that there is no difference in
mechanical results (laxity) between the
bioabsorbable interference screw plus
EndoPearl® (Linvatec, Largo, FL) and
EndoButton® (Smith & Nephew, Andover, MA).
METHODS: After Research and Ethics Board
approval, 51 sequential patients from the Ottawa
Hospital undergoing arthroscopy-assisted ACL
reconstruction by a single surgeon were recruited.
Inclusion criteria included: normal contra-lateral
knee, isolated ACL injury, closed tibial physis, no
previous knee surgery and ability to complete 2-
year follow-up. After drilling tunnels, a computergenerated
randomization table was used to
allocate patients to a study arm. The patients were
assessed with IKDC scores and had KT-1000
arthrometer measurements taken at 6 weeks, and
3, 6, 9, 12, and 24 months post-operatively by
independent clinical observers.
RESULTS: 49 patients (26 EB, 23 BS/EP)
completed follow-up of 2 years. Average side-toside
differences on KT-1000 manual maximum
scores at 2 years were 1.8 +/- 2.4mm for
EndoButton® and 2.2 +/- 4.9mm for the bioscrew
plus EndoPearl® (p=0.58). Thsee differences in
mechanical laxity at all times to 2 years are not
statistically significant. Average IKDC scores were
85.9 +/- 9.8 for EndoButton® and 84.0 +/- 10.2 for
the bioscrew-EndoPearl®, respectively (p=0.51).
DISCUSSION: The EndoButton® has been shown
to have excellent laboratory (Kousa P et al, AJSM
2003) and clinical (Ma CB et al, Arthroscopy 2004)
results. Bioscrew interference fit and pull-out
strength is bone-quality dependant. The addition
of EndoPearl® to the aperture bioscrew femoral
fixation decreases clinical laxity (Macdonald,
AJSM 2004).
CONCLUSION: The 2-year IKDC scores support
the nul hypothesis: EndoButton® and bioscrew
plus EndoPearl® provide equal femoral fixation in
4-bundle hamstring ACL reconstruction. Both
methods of femoral fixation have evidence of
excellent clinical results.
E-poster #316
Clinical Short Term Outcome of Anterior
Cruciate Ligament Reconstruction with
Quadrupled Hamstring Tendon Graft and
Bioabsorbable Tibial Cross Pin Fixation
Matthias Klepsch, Munich, GERMANY, Presenter
Tomas Buchhorn, Munich, GERMANY
Center of Sports Medicine, Orthozentrum,
Munich, GERMANY
Purpose: To report the one year results of
quadrupled hamstring tendon autograft anterior
cruciate ligament reconstruction with
bioabsorbable tibial cross pin fixation.
Material and Method: In a prospective study we
compared the clinical outcome of 30 aclreconstructions
with tibial interference screw
fixation with 30 tibial cross pin fixation (rigid fix,
Mitek®). Femoral graft fixation in both groups was
with the rigid fix femoral cross pin system by
Mitek®. We report the one year results.
Results: The mean Lysholm score was 90 (range,
44 to 97), the mean Tegner activity score was 5.6
(range, 3 to 7) for the tibial interference screw
graft fixation group. For the tibial cross pin group
the Lysholm score was 84 (range, 38 to 92) and
the Tegner activity score was 4.5 (range, 2 to 5).
The KT-1000 arthrometer mean side-to-side
difference for manual maximum displacement
was 2.6 mm (range, 0 to 8) for the tibial
interference screw fixation group and 4.2 mm
(range, 2 to 10) for the tibial cross pin group. The
mean IKDC knee score was 85 (range, 48 to 99) for
the tibial interference screw fixation group and 79
(range, 42 to 85) for the tibial cross pin group. In 7
patients (23%) of the tibial cross pin group, we
observed loosening of the distal pin of the two
tibial fixation pins. The earliest lossening with
skin prolabation was reported 6 weeks post-op.
The latest 9 weeks post-op. In all cases we had to
remove the distal pin with a local incision,
because of pain while kneeling or threatening
skin penetration. All knees with cross pin
loosening showed increased knee laxity in the KT-
1000 after six month.
Conclusions: Quadrupled hamstring tendon
autograft acl-reconstruction with tibial
bioabsorbable interference screw fixation and
femoral cross pin fixation is comparable with
other methods of acl-reconstruction in terms of
patient satisfaction, knee stability, and function.
Tibial fixation with the rigid fix cross pin system is
not recommendable due to increased laxity and
distal pin loosening. Further studies have to be