Improving Tendon-to-Bone Healing Through Regenerative Medicine Strategies

(funded by NIH R01/R56 AR057836) 41-51

Microscopic images of tendon to bone transition
Figure 5: The functionally graded transition between tendon and bone is not regenerated during the healing process (healthy attachment is shown on the left, healing attachment is shown on the right; hematoxylin- and eosin-stained images are shown under bright field in the top row and under polarized light in the bottom row).

Healing of tendon to bone does not reproduce the structural or compositional features of the healthy enthesis 42,44,52 (Figure 5). This results in a mechanically inferior attachment that is prone to rupture. Healing can be improved through the implementation of design criteria from the uninjured attachment (e.g., through surgical manipulation), application of the roadmap defined from developmental biology studies (e.g., through the application of growth factor or cell-based therapies), or application of tissue engineered scaffolds. Prior and ongoing studies are evaluating the role of mechanical loading,42,45,48,53,54 growth factors,47,55 functionally graded scaffolds,25,28-31 and mesenchymal stem cells29,33,34 on tendon-to-bone repair. Results have demonstrated that healing of tendon to bone can be modulated by controlling loading across the repair site and that growth factor- and cell-based therapies hold great promise for regenerating the native enthesis.