Rotator cuff injuries are extremely common and hugely debilitating. ACC data shows that rotator cuff injuries cost the New Zealand healthcare system over $113 million per annum, with approximately 1000 rotator cuff repairs performed annually. Currently, 30-70% of rotator cuff surgeries fail due to ineffective tendon-bone healing. Obesity is a major factor contributing to poor healing, although the mechanism for this is not well understood. Using proven animal models, we can clarify these obesity-related pathological changes and study promising new treatments to improve tendon surgical repair. These results can rapidly translate into clinical practice and provide significant health gains for the growing number of patients affected by rotator cuff injuries.