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Updated: Aug 24, 2026
A Mini-Invasive Internal Fixation Technique for Studying Immobilization-Induced Knee Flexion Contracture in Rats
Published on: May 20, 2019
Initial fixation strength of two bioabsorbable pins for the fixation of hamstring grafts compared to interference
Thore Zantop1, Andre Weimann, Markus Rümmler
1Department of Orthopaedic Surgery, Christian-Albrechts-University Kiel, Kiel, Germany.
Background:
During the early postoperative period, the fixation of a hamstring graft to the bone tunnel is the primary factor in limiting rehabilitation.
Hypothesis:
The initial fixation strength of a double cross pin fixation technique is comparable with the biodegradable interference screw fixation technique.
Study Design:
Experimental laboratory study.
Methods:
The authors examined the initial fixation strength of two 3.3-mm bioabsorbable pins compared to interference screws for hamstring grafts in bovine knees.
Results:
Analysis of yield load, maximum load, and stiffness in the single-cycle loading test showed no statistically significant differences for cross pin and interference fixation (P <.05). For cross pins and interference screws, the mean displacement under 1000 cycles to 250 N was 5.07 ( +/- 1.9) mm and 4.81 ( +/- 2.5) mm, stiffness 252 ( +/- 78) N/mm and 289 ( +/- 148) N/mm. Only grafts fixed with cross pins survived 1000 cycles to 450 N.
Conclusion:
The initial fixation strength of the double cross pin technique is comparable to that of interference screw fixation with a stiffness comparable to that of the native ACL.
Clinical Relevance:
Hamstring graft fixation using two cross pins provides an alternative to bioabsorbable interference screw fixation.
