2017 ISAKOS Biennial Congress ePoster #1723

 

Biomechanical Evaluation of Suture Anchor versus Transosseous Tunnel Patella Tendon Repair Techniques

Seth L. Sherman, MD, Redwood City, CA UNITED STATES
Brandee S. Black, MD
Matthew A Mooberry, BS, Columbia, MO UNITED STATES
Katie Freeman, MD, Papillion, NE UNITED STATES
Jeff L. Milles, MD, Columbia, MO UNITED STATES
David Flood, MD, Columbia, Missouri UNITED STATES
Ferris M. Pfeiffer, PhD, Boonville, MO UNITED STATES

University of Missouri, Columbia, MO, UNITED STATES

FDA Status Cleared

Summary

In this cadaveric model, suture anchor repair demonstrated similar biomechanical profile regarding cyclic loading and ultimate load to failure when compared to ‘gold standard’ transosseous tunnel patella tendon repair.

Abstract

Objectives: The current gold standard for management of an acute patella tendon rupture is surgical repair through transosseous patellar bone tunnels. Few studies have been published comparing the biomechanical properties of suture anchor versus transosseous patella tendon repair.

Methods

Twelve cadaveric ‘patella-only’ specimens were used. DXA measurement was performed to ensure equal bone quality amongst groups. Specimens were randomly assigned to either a suture anchor repair of patella tendon group (n=6) or a transosseous tunnel repair group (n=6). Suture type and repair configuration were equivalent. After the respective procedures were performed, each patella was mounted into a gripping jig. Tensile load was applied at a rate of 0.1 mm/s up to 100N after which cyclic loading was applied at a rate of 1 Hz between magnitudes of 50-150N, 50-200N, 50-250N, and tensile load at a rate of 0.1mm/s until failure. Failure was defined as a sharp deviation in the linear load versus displacement curve. Failure mode was recorded. Results were compared statistically.

Results

DXA demonstrated no significant differences in bone quality between the two groups (p=.075). Cyclic displacement to 100N, 50-150N, 50-200N, and 50-250N of the suture anchor and transosseous groups was measured. The ultimate load to failure of the transosseous tunnel and suture anchor groups was 287.02N +/-100.82 and 258.46N +/-63.04, respectively, with no significant differences found between groups. (p=0.43) All specimens within the suture anchor cohort failed by pulling out suture anchors except for one which failed through tendon midsubstance. All specimens within the transosseous cohort failed through the midsubstance of the tendon except for one which failed through suture breakage.

Conclusions

In this cadaveric model, suture anchor repair demonstrated a similar biomechanical profile regarding cyclic loading and ultimate load to failure when compared to the "gold standard" transosseous tunnel patella tendon repair. While in vivo study is still required, suture anchor patella tendon repair may be a viable alternative to transosseous repair. The benefits include decreased surgical dissection and reduced risk of patella fracture, although cost effectiveness is a concern. Both repair strategies have decreased force to failure versus native patella tendon, suggesting that a protective early rehabilitation strategy may be advisable.