Dual poly liner mobility optimizes wear and stability in THA: opposes.
Orthopedics
; 34(9): e449-51, 2011 Sep 09.
Article
en En
| MEDLINE
| ID: mdl-21902127
ABSTRACT
Total hip arthroplasty (THA) is an effective intervention for the treatment of arthrosis with excellent survivorship. Nonetheless, dislocation and osteolysis remain significant complications. A dual-mobility acetabular component has been advocated to improve stability and wear. Stability is imparted by increasing the effective femoral head size, which allows a larger range of motion (ROM) before neck-socket impingement occurs. Increasing ROM, however, introduces an additional problem of bony impingement of the trochanter against the pelvis. Consequently, there is little improvement in ROM for heads >36 to 40 mm. A 0.4% incidence of instability at the larger articulation has been reported in primary THA using the dual-mobility liner, which is equivalent to reports for conventional THA. The dual-mobility liner has introduced the unique complication of intraprosthetic dislocation, where the femoral head dissociates at the smaller articulation as a result of polyethylene wear. An incidence of intraprosthetic dislocation of 3.6% has been reported, which far exceeds dislocation of conventional arthroplasty. The dual-mobility liner is a monoblock acetabular component without the capacity for augmented bony fixation. Inability to achieve primary stability has been reported as high as 18% and therefore its usefulness in revision THA is questionable. Proponents of the dual-mobility liner cite improved wear characteristics over conventional THA; however, few studies support this proposition. Retrieval studies have reported that the dual-mobility liner does not avoid wear or osteolysis. Theoretically, it is inconceivable that wear would be diminished with an additional articulation with a huge surface area, where the differential hardness has been reversed to a soft-on-hard bearing.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Artroplastia de Reemplazo de Cadera
/
Luxación de la Cadera
/
Prótesis de Cadera
/
Inestabilidad de la Articulación
Idioma:
En
Revista:
Orthopedics
Año:
2011
Tipo del documento:
Article
País de afiliación:
Canadá