title: Continuous monitoring of the performance of hip prostheses.
abstract: New brands of joint prosthesis are released for general implantation with limited evidence of their long-term performance in patients. The CUSUM continuous monitoring method is a statistical testing procedure which could be used to provide prospective evaluation of brands as soon as implantation in patients begins and give early warning of poor performance. We describe the CUSUM and illustrate the potential value of this monitoring tool by applying it retrospectively to the 3M Capital Hip experience. The results show that if the clinical data and methodology had been available, the CUSUM would have given an alert to the underperformance of this prosthesis almost four years before the issue of a Hazard Notice by the Medical Devices Agency. This indicates that the CUSUM can be a valuable tool in monitoring joint prostheses, subject to timely and complete collection of data. Regional or national joint registries provide an opportunity for future centralised, continuous monitoring of all hip and knee prostheses using these techniques.
authors.affiliation: The Clinical Effectiveness Unit, The Royal College of Surgeons of England, 35-43 Lincoln's Inn Fields, London WC2A 3PE, UK.
authors.forename: S L
authors.initials: SL
authors.lastname: Hardoon
authors.forename: J D
authors.initials: JD
authors.lastname: Lewsey
authors.forename: P J
authors.initials: PJ
authors.lastname: Gregg
authors.forename: B C
authors.initials: BC
authors.lastname: Reeves
authors.forename: J H P
authors.initials: JH
authors.lastname: van der Meulen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation; D005260:Female; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011358:Product Surveillance, Postmarketing / Q000379:methods*; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods; D013997:Time Factors