Modeling the Cost-Effectiveness for Cement-Less and Hybrid Prosthesis in Total Hip Replacement in Emilia Romagna, Italy Gian Luca Di Tanna, M.Phil., M.Sc.,* , † ,1 Salvatore Ferro, M.D.,‡ Filippo Cipriani, Ph.D.,† Barbara Bordini, MAS,§ Susanna Stea, Ph.D.,§ Aldo Toni, M.D.,§ Federico Silipo, Ph.D.,jj Giampiero Pirini, Ph.D.,jj and Roberto Grilli, M.D.* *Department of Experimental Medicine, Sapienza University of Rome, Italy; †Regional Agency for Health and Social Care, Regione Emilia Romagna, Bologna, Italy; ‡Servizio Presidi Ospedalieri-Assessorato Politiche per la Salute Emilia Romagna, Bologna, Italy; §Laboratorio Tecnologia Medica, Istituto Ortopedico Rizzoli, Bologna, Italy; and jj Gruppo Regionale Tecnologie Sanitarie-Dir. Gen. San. Pol. Soc. Emilia Romagna, Bologna, Italy Submitted for publication August 4, 2009 Background. The aim of the present study was to as- sess the cost-effectiveness of cement-less versus hybrid prostheses in total hip replacement (THR) in patients diagnosed with primary osteoarthritis. Methods. Effectiveness data were obtained from the Emilia-Romagna Regional Registry on Orthopaedic Prosthesis (RIPO), which collects information on all or- thopaedic intervention performed in Emilia-Romagna (41,199 total hip replacements performed from 2000 to 2007), and from which we obtained survival curves and transition probabilities for the cement-less and hybrid prostheses, respectively. Conversely, costs were derived from regional databases through a spe- cific procedure, which allowed us to register individual component’s costs for both primary and subsequent revision interventions. A specific Markov transition model was constructed in order to consider the 3 types of revisions that an implant could possibly undergo through its life-span: total, cup or stem, head insert or neck. The cost-effectiveness was expressed in terms of cost per ‘‘revision-free’’ life year. Results and conclusions. Considering a 70-y old pa- tient undergoing THR, the cementless strategy re- sulted more effective but more costly than the hybrid solution, with an incremental cost effectiveness ratio of 2401.63 V per revision-free life year. Following a de- terministic sensitivity analysis, hybrid and cementless fixation showed, respectively, a dominance profile for patients older than 83 y and younger than 43 y, whereas for all ages in between, we report a progres- sive increase in the ICER of cementless prostheses. Our results proved to be robust, as underlined by the probabilistic sensitivity analysis performed using cost distributions. Ó 2011 Elsevier Inc. All rights reserved. Key Words: total hip replacement; cost effectiveness analysis; Markov model; sensitivity analysis; economic evaluation. INTRODUCTION The successful history of total hip replacement (THR) has been well documented and recently described as ‘‘the operation of the century’’ [1]. Over the past de- cades, it has been established as a successful surgical intervention, with an excellent risk/benefit profile, de- livering superb clinical results. Additionally, it has been proven to have a favorable cost-effectiveness pro- file, comparable to other commonly accepted proce- dures and, thus, providing ‘‘value for money’’ [2]. Nevertheless, despite its unquestionable positive im- pact on patient’s clinical status, a number of factors keep total hip replacement surgery constantly under the spotlight. On one hand, it has become one of the most frequent causes of hospital admission for elective surgery, and its demand is projected to increase in the future: driven by the progressive shift towards an older population, characterized by a higher prevalence for arthritic dis- ease [3]. On the other hand, in recent years, the mean age for primary intervention has shifted towards much younger ages [4]. Finally, implants tend to wear 1 To whom correspondence and reprint requests should be addressed at Department of Experimental Medicine, Sapienza Uni- versity of Rome, (I Clinica medica, Torre di ricerca II piano, stanza 13) Via del Policlinico 155, 00161 Rome, Italy. E-mail: gianluca. ditanna@uniroma1.it. 0022-4804/$36.00 Ó 2011 Elsevier Inc. All rights reserved. 227 Journal of Surgical Research 169, 227–233 (2011) doi:10.1016/j.jss.2009.10.031