Biomechanical Evaluation of Proximal Hamstring Repair: All-Suture Anchor Versus Titanium Suture Anchor

Alexander Otto; Alyssa M DiCosmo; Joshua B Baldino; Julian Mehl; Elifho Obopilwe; Mark P Cote; Andreas B Imhoff; Knut Beitzel; Augustus D Mazzocca; Katherine Coyner

doi:10.1177/2325967119892925

Biomechanical Evaluation of Proximal Hamstring Repair: All-Suture Anchor Versus Titanium Suture Anchor

Orthop J Sports Med. 2020 Jan 2;8(1):2325967119892925. doi: 10.1177/2325967119892925. eCollection 2020 Jan.

Authors

Alexander Otto^{1

2

3}, Alyssa M DiCosmo¹, Joshua B Baldino¹, Julian Mehl^{1

2}, Elifho Obopilwe¹, Mark P Cote¹, Andreas B Imhoff², Knut Beitzel^{2

4}, Augustus D Mazzocca¹, Katherine Coyner¹

Affiliations

¹ Department of Orthopaedic Surgery, UConn Musculoskeletal Institute, University of Connecticut, Farmington, Connecticut, USA.
² Department of Orthopaedic Sports Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany.
³ Department of Trauma, Orthopaedic, Plastic and Hand Surgery, University Hospital of Augsburg, Augsburg, Germany.
⁴ ATOS Orthoparc Klinik Köln, Cologne, Germany.

Abstract

Background: Proximal hamstring avulsions are severe tendon injuries and are commonly sports-related. Open and endoscopic techniques as well as different anchor configurations have already been described for proximal hamstring repair. Novel all-suture anchors have been developed to provide decreased bone loss during placement and reduced occupied bone volume when compared with titanium suture anchors.

Hypothesis: Complete proximal hamstring avulsions repaired with all-suture anchors will demonstrate equal load to failure and comparable displacement under cyclic loading when compared with titanium suture anchors.

Study design: Controlled laboratory study.

Methods: Complete proximal hamstring avulsions were created in 18 paired cadaveric specimens (mean ± SD age, 63.0 ± 10.4 years). Either all-suture anchors or titanium suture anchors were used for repair. Cyclic loading from 10 to 125 N at 1 Hz was performed for 1500 cycles with a material testing machine. Displacement was assessed along anterior and posterior aspects of the tendon repair with optical tracking. Specimens were loaded to failure at a rate of 120 mm/min. Displacement, load to failure, and repair construct stiffness were compared between matched pairs with the Wilcoxon signed-rank test. Correlations were determined by Spearman rho analysis.

Results: The all-suture anchors showed significantly higher load-to-failure values when compared with the titanium anchor repairs (799.64 ± 257.1 vs 573.27 ± 89.9 N; P = .008). There was no significant difference in displacement between all-suture anchors and titanium suture anchors at the anterior aspect (6.60 ± 2.2 vs 5.49 ± 1.1 mm; P = .26) or posterior aspect (5.87 ± 2.08 vs 5.23 ± 1.37 mm; P = .678) of the repaired hamstring tendons.

Conclusion: All-suture anchors demonstrated similar displacement and superior load to failure when compared with titanium suture anchors.

Clinical relevance: The results of this study suggest that all-suture anchors are an equivalent alternative to titanium suture anchors for proximal hamstring avulsion repair.

Keywords: all-suture anchor; biomechanics; hip; proximal hamstring avulsion; proximal hamstring repair; titanium suture anchor.