Revision in previously satisfied knee arthroplasty patients is the result of their call on the physician, not on pre-planned follow-up: a retrospective study of 181 patients who underwent revision within 2 years.
Bremander AB, Dunbar M, Knutson K, Petersson IF, Robertsson O.
Acta Orthop. 2005 Dec;76(6):785-90.