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Updated: Jun 16, 2026
A Mini-Invasive Internal Fixation Technique for Studying Immobilization-Induced Knee Flexion Contracture in Rats
Published on: May 20, 2019
[Comparative study after hamstring ACL plasty with RigidFix (pin fixation) and EndoButton (anchor fixation)]
E Basad1, A Kipper, O A Wüsten
1Klinik und Poliklinik für Orthopädie und Orthopädische Chirurgie, Universitätsklinikum Giessen und Marburg, Standort Giessen. erhan.basad@ortho.med.unigiessen.de
Aim:
Within a prospective case group study, two hamstring fixation techniques, a pin fixation with RigidFix (RF) and an anchor fixation with EndoButton (EB), were compared.
Method:
67 patients were followed clinically and by MRI preoperatively (t0), at six months (t6) and at twelve months (t12). In one group (N = 21), EB was used for representing a juxta-articular graft fixation. The second group (N = 46) with RF was used to represent the ab-articular fixation. KT-1000 stability measurement, IKDC, Lysholm and Tegner scores were used to determine the clinical outcomes. Reflux and tunnel widening (TW) were investigated by MRI.
Results:
The KT-1000 values were slightly more stable at t6 (EB: 2.1 +/- 4.1 mm, RF: 1.0 +/- 2.5 mm) in the RF group (p = 0.044) but equalised later at t12 (EB: 0.5 +/- 3.1 mm, RF 1.0 +/- 2.4 mm). The median Tegner score at t6 (EB: 4.3 +/- 1.2, RF 4.1 +/- 1.7) and t12 (EB: 5.9 +/- 1.8, RF 5.4 +/- 2.0) were comparable (p = 0.692). The mean Lysholm score at t6 (EB: 90 +/- 11, RF: 91 +/- 8.9) and t12 (EB: 95 +/- 7.5, RF: 95 +/- 7.4) was comparable in each group (p = 0.589). The same was valid in the median of the IKDC score at t6 (EB: II, RF III) and t12 (EB: II, RF III). The category "femoral reflux" showed slight minimal fringe in the EB group at t6 but aligned to "no reflux" together with the RF group at t12 (NS, p = 0.550). A tunnel widening was not detectable in either of the groups.