The 'cotton wool' appearance on radiographs is a classic feature of Paget's disease of bone. It results from the combination of excessive bone resorption and abnormal bone formation, leading to a patchy, sclerotic pattern that resembles cotton wool. This pattern reflects the disorganized and thickened trabecular bone characteristic of this condition. Recognizing this radiological sign is crucial for diagnosis and surgical planning to avoid complications during orthopedic interventions.

Reference: Gray's Anatomy, Susan Standring, 42nd Edition.