2021 ISAKOS Biennial Congress Paper
Comparison Of Pull-Out Strength Following Ligamentum Teres Reconstruction In The Hip: Peek Corkscrew Suture Anchor Versus Cortical Button Fixation: A Cadaveric Study.
Ajay C. Lall, MD, MS, FAAOS, Paramus, New Jersey UNITED STATES
Hari Krishna Ankem, MD, Louisville, KENTUCKY UNITED STATES
Samantha Diulus, BS, Des Plaines, Illinois UNITED STATES
Benjamin G. Domb, MD, Chicago, IL UNITED STATES
American Hip Institute Research Foundation, Des Plaines, Illinois, UNITED STATES
FDA Status Cleared
Summary
This cadaveric study highlighted the differences in pullout strength between two methods of graft fixation over the acetabular fossa that are commonly utilized in LT reconstruction.
Abstract
Background
In recent years, the role of the ligamentum teres (LT) in hip stability has been further explored. Consequently, the consequences of LT tears have also become better understood. LT reconstruction is an appropriate alternative in select cases of full-thickness tears. The technical variations in LT reconstruction fixation at the acetabular fossa are critical to achieve best functional results.
Purpose
The purpose of this study is to compare the pull-out strength of the PEEK corkscrew suture anchor to that of the cortical button fixation for ligamentum teres reconstruction in the hip.
Study design: Cadaveric study
Methods
In eight hip joint specimens, the acetabular socket was prepared after the native ligamentum teres was transected and the femoral head was removed. The pulvinar was excised, to allow for optimal visualization of the cotyloid fossa for placement of the button or anchor fixation device. Eight separate tibialis anterior grafts were then prepared by suturing a running-locking #2 FiberWire (Arthrex, Naples, FL) on each tail of the graft. Specimens were then mounted on a custom jig within a mechanical test frame (MTS Systems, Eden Prairie, MN) to allow for in-line pull of the graft-fixation construct, eliminating any angular or torsional torque. Four specimens were prepared with a suture-button (Arthrex, Naples FL), and the remaining four specimens were prepared with a 3.0-mm knotless, polyether ether ketone (PEEK) Corkscrew anchor (Arthrex, Naples FL). Following the preload, each specimen was loaded to failure at 0.5 mm/s. Stiffness and ultimate pullout force were measured for each specimen construct. Groups were compared statistically using an unpaired two-tailed Student’s t-test, with statistical significance set at p = 0.05.
Results
The suture button type fixation has greater mean pullout strength and required higher load to failure compared to the PEEK corkscrew anchor fixation method (346.0 ± 206.5 N vs. 195.9 ± 50.0 N). There was no significant difference in mean stiffness between the two methods of fixation (21.9 ± 5.4 vs 26.5 ± 5.8 N/mm).
Discussion
This cadaveric study highlighted the differences in pullout strength between two methods of graft fixation that are commonly utilized in LT reconstruction. The suture button type fixation demonstrated greater pullout strength and required a higher load to reach failure compared to the PEEK corkscrew anchor fixation. To our knowledge, this is the first study comparing the different methods of LT reconstruction graft fixation on the acetabular side.
Conclusion
This cadaveric study highlighted the differences in pullout strength between two methods of graft fixation over the acetabular fossa that are commonly utilized in LT reconstruction. The method of suture button type fixation demonstrated better pullout strength and required higher load to failure compared to the PEEK corkscrew anchor fixation. To our knowledge, this is the first study comparing the different methods of LT reconstruction graft fixation on the acetabular side. We strongly believe that the results of this study can guide surgical decision making when selecting a fixation method for the LT graft during reconstruction.