Rotator cuff tears are common in the older population, and the volume of rotator cuff repair continues to rise. Despite refinements in technique, structural failure remains frequent, with reported re-tear rates often over 25% at medium-term follow-up. The first 6 months after repair represent a critical period for failure risk. This review focuses on patient, surgeon and implant factors that influence tendon healing and highlights areas where clinicians can intervene. Increasing age, larger tears, degree of tendon retraction, fatty infiltration and muscle atrophy consistently predict non-healing and should inform counselling and operative planning. Potentially modifiable patient factors include glycaemic control, body mass index, nutrition, vitamin D status and bone mineral density. On the surgical side, repair configuration and mechanical stability appear most important for larger tears, while the benefits of routine subacromial decompression or footprint microfracture remain uncertain. Augmentation options such as dermal allografts, platelet-rich plasma and bioinductive collagen implants may improve structural integrity in high-risk tears, although consistent functional gains have not been demonstrated. A pragmatic approach combines risk stratification with optimization of modifiable factors, robust fixation and a rehabilitation programme that protects the repair while restoring function.