Revision of Metal-on-metal Hip Arthroplasty with Well Fixed and Positioned Acetabular Component Using a Dual-mobility Head and Review of Literature

Abstract

Background:As a consequence of use of metal-on-metal hip arthroplasties some patients have precised revision for pain or metal hipersensivity reactions among other causes. We propose to salvage monoblock acetabular component and femoral component using a dual-mobility head and perform a lower morbidity operation in young patients preserving host bone stock in cases with well fixed and positioned components.Objective:(1) What clinical problems have been reported in patients with Metal-on-metal hip arthroplasties? (2) Could the tribocorrosion potentially cause a fracture of neck femoral component? (3) Can be the dual-mobility head a recourse in metal-on-metal hip revision?Methods:Ten patients were revised for pain or/and raised Cobalt/Chromium levels between August 2012 and December 2015. In three cases femoral neck component was fractured and femoral revision was necessary. In four hips, acetabular and femoral components could be maintained. Age, body index mass, ion levels, acetabular position, size of acetabular component and femoral head, approach, blood transfunsion and time of hospitalization were analized. Results:At a mean follow-up of 25,6 months (6 to 45) the mean postoperative HHS was 92. It was not statistically significant because several patients were low sintomatic before surgery, but had raised Cobalt/Chromium levels in the blood. All patients had near-normal levels of Cobalt/Chromium during the first 6 months after revision surgery. No relevant complications were reported. Conclusion:The use of dual-mobility head can be an acceptable option to revise metal-on-metal arthroplasties correctly oriented with abscence of loosening or infection signs and keeping bone stock in young patients.

Revision of a Monoblock Metal-on-Metal Cup Using a Dual Mobility Component: Is It a Reasonable Option?

“…The rationale of leaving the well-fixed acetabular component in situ and converting the implant to a dual mobility is certainly correct and starts from the assumption to reduce intra-and post-operative morbidity and to preserve bone stock, as documented by several reports [12,20,22,25,26]. Nevertheless, the incidence of so many cases of complications for a total of 10.77%, of which 10 (7.6%) of true dislocations and intra-prosthetic dislocations in a such short period of time, requires proper debate and consideration, especially considering that the majority of procedures are off-label practices, therefore unsupported by the Food and Drug Administration, the European International Medical Devices Regulators Forum and manufacturers.…”

“…Some authors reported that cup revision in MoM can be technically difficult [13], it is often associated with loss of bone stock and could increase the risk of dislocation when small heads are used for revision surgery [14]. Therefore, it has been proposed to leave in place the acetabular component and to convert the implant into a dual mobility system [13,[15][16][17][18][19][20][21][22][23][24][25][26]. Although dual mobility (DM) bearings offer an easy solution avoiding the intraoperative and time-associated complications related to the removal of a well-fixed and well-positioned acetabular shell, other considerations should be evaluated before this new solution is considered as reliable and reproducible.…”

Cotilos de doble movilidad. Uso para la revisión femoral aislada de prótesis de cadera con fricción metal/metal con cabezas grandes. [Use of dual mobility acetabular cups for isolated femoral revision of metal on metal hip resurfacing arthroplasty using larger femoral heads]

“…Se han publicado casos similares, con buenos resultados. [12][13][14][15][16] Pritchet, cirujano de los EE.UU., presentó 14 casos con 41 meses de seguimiento. No describe revisiones ni ningún tipo de complicaciones.…”

“…Destacan la preservación del stock óseo y la ausencia de complicaciones. 15 Estas copas, como bien se ha descrito en esta revista, poseen una doble articulación. 17 Se usan en Europa desde hace décadas, pero recién, en 2009, fueron aprobadas por la Food and Drug Administration.…”