title: Five to thirteen year results of a cemented dual mobility socket to treat recurrent dislocation.
abstract: Dual mobility (DM) socket has been associated with a low rate of dislocation following both primary and revision total hip arthroplasty (THA). However, little is known about the long-term efficiency of DM in the treatment of THA instability. The purpose of this retrospective study was to evaluate the outcome of a cemented DM socket to treat recurrent dislocation after a minimum of five year follow-up.
  
  
  
  The series included 51 patients with a mean age of 71.3 ± 11.5 (range, 41-98) years presenting with recurrent dislocation (mean 3.3). A single DM socket design was used consisting of a stainless steel outer shell with grooves with a highly polished inner surface articulating with a mobile polyethylene component. The femoral head was captured in the polyethylene component using a snap-fit type mechanism, the latter acting as a large unconstrained head inside the metal cup.
  
  
  
  At the minimum five year follow-up evaluation, 18 of the 51 patients deceased at a mean of 4.8 ± 2.3 years, three were lost to follow-up at a mean of 1.4 years, seven had been revised at a mean of 4.7 ± 3.1 years (range, 1.5-9.1), and the remaining 23 were still alive and did not have revision at a mean of 8.2 ± 2.4 years (range, 5-13 years). Of the seven revision, three were performed for further episodes of dislocation (at the large bearing for one patient and intra-prosthetic for two patients) after a mean 5.9 ± 2.9 years (range, 2.7-9.1), whereas two were performed for late sepsis and two for aseptic loosening of the acetabular component. Radiographic analysis did not reveal any further loosening on the acetabular side. The survival rate of the cup at ten years, using re-dislocation as the end-point, was 86.1 ± 8.4% (95% confidence interval, 69.7-100%). The survival rate of the cup at ten years, using revision for any reason as the end-point, was 75.2 ± 9.3% (95% confidence interval, 56.9-93.5%).
  
  
  
  A cemented dual mobility cup was able to restore hip stability in 94% of patients presenting with recurrent dislocating hips up to 13-year follow-up with none of the complications associated with constrained devices, as mechanical failure occurred in only 3.9% of the patients of this series. The overall reduced survival using revision for any reason as the end-point at ten years was related to this specific patients population that had various co-morbidities.
authors.affiliation: Clinical Orthopaedic Research Centre, Department of Reconstructive and Orthopaedic Surgery, Université René Descartes, Hôpital Cochin (AP-HP), Paris, France. moussah@club-internet.fr.|Clinical Orthopaedic Research Center, Department of Orthopaedic and Reconstructive Surgery, Service A, Centre Hospitalo-Universitaire Cochin- Port Royal, 27 Rue du Faubourg St Jacques, 75014, Paris, France. moussah@club-internet.fr.
authors.forename: Moussa
authors.initials: M
authors.lastname: Hamadouche
authors.affiliation: Clinical Orthopaedic Research Centre, Department of Reconstructive and Orthopaedic Surgery, Université René Descartes, Hôpital Cochin (AP-HP), Paris, France.|Department of Orthopaedic Surgery and Traumatology, Pontchaillou University Hospital, 2 Avenue Henri Le Guilloux, 35203, Rennes, France.
authors.forename: Mickael
authors.initials: M
authors.lastname: Ropars
authors.affiliation: Clinical Orthopaedic Research Centre, Department of Reconstructive and Orthopaedic Surgery, Université René Descartes, Hôpital Cochin (AP-HP), Paris, France.|Clinical Orthopaedic Research Center, Department of Orthopaedic and Reconstructive Surgery, Service A, Centre Hospitalo-Universitaire Cochin- Port Royal, 27 Rue du Faubourg St Jacques, 75014, Paris, France.
authors.forename: Camille
authors.initials: C
authors.lastname: Rodaix
authors.affiliation: Clinical Orthopaedic Research Centre, Department of Reconstructive and Orthopaedic Surgery, Université René Descartes, Hôpital Cochin (AP-HP), Paris, France.|Clinique Mutualiste de la Porte de Lorient, 3, rue Robert de La Croix, 56324, Lorient Cedex, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Musset
authors.affiliation: Clinical Orthopaedic Research Centre, Department of Reconstructive and Orthopaedic Surgery, Université René Descartes, Hôpital Cochin (AP-HP), Paris, France.|Hotel Dieu, 29120, Pont Labbé, France.
authors.forename: François
authors.initials: F
authors.lastname: Gaucher
authors.affiliation: Clinical Orthopaedic Research Centre, Department of Reconstructive and Orthopaedic Surgery, Université René Descartes, Hôpital Cochin (AP-HP), Paris, France.|Clinical Orthopaedic Research Center, Department of Orthopaedic and Reconstructive Surgery, Service A, Centre Hospitalo-Universitaire Cochin- Port Royal, 27 Rue du Faubourg St Jacques, 75014, Paris, France.
authors.forename: David
authors.initials: D
authors.lastname: Biau
authors.affiliation: Clinical Orthopaedic Research Centre, Department of Reconstructive and Orthopaedic Surgery, Université René Descartes, Hôpital Cochin (AP-HP), Paris, France.|Clinical Orthopaedic Research Center, Department of Orthopaedic and Reconstructive Surgery, Service A, Centre Hospitalo-Universitaire Cochin- Port Royal, 27 Rue du Faubourg St Jacques, 75014, Paris, France.
authors.forename: Jean Pierre
authors.initials: JP
authors.lastname: Courpied
authors.affiliation: Clinical Orthopaedic Research Centre, Department of Reconstructive and Orthopaedic Surgery, Université René Descartes, Hôpital Cochin (AP-HP), Paris, France.|Department of Orthopaedic Surgery and Traumatology, Pontchaillou University Hospital, 2 Avenue Henri Le Guilloux, 35203, Rennes, France.
authors.forename: Denis
authors.initials: D
authors.lastname: Huten
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D001843:Bone Cements / Q000009:adverse effects / Q000627:therapeutic use; D005260:Female; D005500:Follow-Up Studies; D006617:Hip Dislocation / Q000209:etiology / Q000601:surgery*; D006621:Hip Joint / Q000601:surgery; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design / Q000379:methods*; D012086:Reoperation; D012189:Retrospective Studies; D016019:Survival Analysis
chemical_list: D001843:Bone Cements
keywords: Cemented; Dislocation; Dual mobility; Survival; Total hip arthroplasty