Autograft Long Head Biceps Tendon Can Be Used as a Scaffold for Biologically Augmenting Rotator Cuff Repairs

According to new study, a viable, mechanically expanded autograft long head biceps tendon (LHBT) scaffold may biologically augment repair and regeneration of torn rotator cuffs. The clinical relevance of the same is that biologically active construct may help to improve the quality of healing and regeneration at the repair site of rotator cuff tears, especially those at high risk for retear. The study has been published in the journal Arthroscopy.

The proximal aspect of the tenotomised LHBTs was harvested from patients during rotator cuff repair surgery and was mechanically formed into porous scaffolds using a surgical graft expander. LHBT scaffolds were evaluated for change in area, tensile properties, and tenocyte viability before and after expansion. The ability of endogenous tenocytes derived from the LHBT scaffold to promote tenogenic differentiation of human adipose-derived mesenchymal stromal cells (ADMSCs) was also determined.

Statistical analysis of the data was performed using GraphPad Prism 7 software. Statistical comparisons between study groups were performed using a Students t-test of equal variance. Significance was defined as P less than or equal to .05.

Results of the study:

• Autograft LHBTs were successfully expanded using a modified surgical graft expander to create a porous scaffold containing viable resident tenoctyes from patients undergoing rotator cuff repair.

• LHBT scaffolds had significantly increased area (length: 24.91 mm [13.91, 35.90] x width: 22.69 mm [1.87, 34.50]; P = .011) compared with the native LHBT tendon (length: 27.16 mm [2.70, 33.62] x width: 6.68 mm [5.62, 7.74]).

• The structural properties of the autograft were altered, including the ultimate tensile strength (LHBT scaffold: .56 MPa [.06, 1.06] vs. native LHBT: 2.35 MPa [1.36, 3.33]; P = .002) and tensile modulus (LHBT scaffold: 4.72 MPa [-.80, 1.24] versus native LHBT: 37.17 MPa [24.56, 49.78]; P = .001).

• There was also a reduction in resident tenocyte percent viability (LHBT scaffold: 38.52% [17.94, 59.09] vs. native LHBT: 68.87% [63.67, 74.37] P =.004).

• Tenocytes derived from the LHBT scaffold produced soluble signals that initiated ADMSC differentiation into an immature tenocyte-like phenotype, as indicated by an 8.7x increase in scleraxis (P = .040) and a 3.6x increase in collagen type III mRNA expression (P = .050) compared with undifferentiated ADMSC controls.

This study has established that:

1) LHBT from patients undergoing rotator cuff repair can be formed into porous autograft scaffolds.

2) Scaffolds exhibited reduced mechanical properties and viable autologous tenocytes compared with native LHBT.

3) Tenocytes from LHBT scaffolds produced cytokines that promoted the initiation of tenogenic differentiation in ADMSCs, and

4) LHBT scaffolds supported ADMSC alignment and acquisition of a tenocyte-like morphology.

Further reading:

Autograft Long Head Biceps Tendon Can Be Used as a Scaffold for Biologically Augmenting Rotator Cuff Repairs

Gregory Colbath, M.D., M.S., Alison Murray, M.S., Sandra Siatkowski, B.S., Taylor Pate, M.D., Mario Krussig, B.S., Stephan Pill, M.D., Richard Hawkins, M.D.,John Tokish, M.D., and Jeremy Mercuri, Ph.D

https://doi.org/10.1016/j.arthro.2021.05.064

Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 38, No 1 (January), 2022: pp 38-48