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Updated: Oct 17, 2026
Murine Hind Limb Explant Model for Studying the Mechanobiology of Achilles Tendon Impingement
Published on: December 8, 2023
Biomechanical comparison of an ultrasound-guided minimally invasive modified Kessler construct and an open Krackow
Chia Ming Chang1, Tung Ying Lee2, Meng Chun Tsai2
1Institute of Medical Sciences, Tzu Chi University, Hualien, 970374, Taiwan; Department of Orthopedic Surgery, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, 970473, Taiwan.
Background:
Open Achilles tendon repair can cause wound-related complications. Ultrasound-guided minimally invasive repair may reduce soft-tissue disruption, but its biomechanical performance requires further evaluation. This study compared the initial biomechanical performance of an ultrasound-guided minimally invasive modified Kessler construct with an open Krackow construct in a cadaveric model.
Methods:
Twelve fresh-frozen cadaveric Achilles tendons were transected 4 cm proximal to the calcaneal insertion and allocated to an open Krackow group (n = 6) or an ultrasound-guided minimally invasive modified Kessler group (n = 6). Testing included 10 loading cycles (50 N at 2.1 mm/s) followed by pull-to-failure testing (25 mm/s). Maximum load to failure and failure modes were recorded.
Findings:
No statistically significant difference in maximum load to failure was observed between the Krackow (149.2 ± 39.0 N) and ultrasound-guided minimally invasive modified Kessler (148.5 ± 22.8 N) constructs (Mann-Whitney U test, U = 18, p > 0.05). All specimens completed the initial cyclic loading phase. In the minimally invasive group, three specimens failed after 5-mm gapping and three by suture knot breakage; in the Krackow group, five failed after 5-mm gapping and one by suture rupture.
Interpretation:
The ultrasound-guided minimally invasive modified Kessler construct demonstrated load-to-failure performance comparable to the open Krackow construct. When both repairs use four core strands crossing the repair site, the overall construct may reduce the mechanical difference expected from suture configuration alone. However, this small cadaveric cohort does not establish formal biomechanical equivalence or isolate the independent contribution of ultrasound guidance.
