Arthroscopy - 2026-04-08 - Journal Article
Pressed Long Head of the Biceps Tendon Autograft Augmentation Enhances Tendon-to-Bone Healing in a Rat Model of Rotator Cuff Repair.
Hatae F, Itoigawa Y, Tsurukami H, Yoshida K, Tatebayashi Y, Morikawa D, Uehara H, Saigo Y, Yoshimura Y, Maezawa K, Ishijima M
Topics
Key Takeaway
Pressed LHBT autograft augmentation increased ultimate load to failure by 63% at 6 weeks (51.5 N vs 31.5 N) in a rat infraspinatus repair model.
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Summary
This study asked whether pressed LHBT autograft augmentation improves tendon-to-bone healing biology and mechanical strength after rotator cuff repair in a rat model. Bilateral infraspinatus tears were repaired with or without pressed LHBT augmentation and evaluated histologically and mechanically at 3 and 6 weeks. The augmentation group showed significantly greater fibrocartilage area (0.35 vs 0.22 mm²), higher COL1/COL3 ratio at both timepoints, and 63% greater ultimate load to failure at 6 weeks (51.5 N vs 31.5 N).
Key Limitation
The 6-week endpoint captures early healing only and does not address whether the mechanical and histological advantages persist through remodeling phases relevant to clinical retear risk.
Original Abstract
PURPOSE
To investigate the underlying regeneration mechanisms of biological augmentation using pressed long head biceps tendon (LHBT) in a rat model.
METHODS
Bilateral infraspinatus tendons were torn and repaired 1 week later in 32 Sprague-Dawley rats. In the biologic augmentation (BA) group, the LHBT was extracted, pressed, and augmented on the repair site. Histological evaluation was performed at 3 and 6 weeks to measure the thickness of the repaired tendon, number of chondrocytes and non-chondrocytes, percentage of aligned chondrocytes, areas of fibrocartilage and collagen fiber, and COL1/COL3 ratio. Genetic expression of collagen types 1 and 3 (COL1 and COL3, respectively); matrix metalloproteinases-1, 3, and 13; and transforming growth factor beta were measured at 3 and 6 weeks. Mechanical testing was performed at 3 and 6 weeks.
RESULTS
Tendon thickness (3.72 mm vs 2.83 mm; P = .01), number of chondrocytes (73.8 vs 39.7; P = .01), fibrocartilage area (0.35 vs 0.22 mm 2 ; P = .03), and collagen fiber area (0.20 vs 0.11 mm 2 ; P = .03) at 6 weeks were significantly higher in the BA group than in the control group. COL1/COL3 ratio at 3 and 6 weeks was significantly higher in the BA group than in the control group (3 weeks, 1.01 vs 0.51; P = .01 and 6 weeks, 0.68 vs 0.27; P = .04). COL3 expression at 6 weeks was significantly lower in the BA group (P = .02). Matrix metalloproteinase-1 expression at 3 weeks was significantly higher in the BA group (P = .005). The ultimate load to failure at 6 weeks was significantly higher in the BA group (51.5 N vs 31.5 N; P = .03).
CONCLUSIONS
Biological augmentation using pressed autologous LHBT promoted tendon-to-bone healing and enhanced mechanical strength.
CLINICAL RELEVANCE
Augmentation with pressed LHBT may improve the biology and mechanical strength of rotator cuff repair.