DURALOC® Acetabular Cup System

The DURALOC® Acetabular Cup is a cementless cup that was introduced in 1990 and has a 13A* ODEP rating1. The DURALOC Cup is a dome loaded cup, which helps ensure improved liner/shell congruency, a minimum polyethylene thickness of 6mm and a secure locking mechanism. These features, combined with POROCOAT® Porous Coating, are designed to help enhance the long-term fixation of the shell.

DURALOC® Acetabular Cup System

Features & Benefits

  • Optimum polyethylene thickness

    Polyethylene liner thickness has been shown to affect the performance of the acetabular cup. Thin liners (below 4mm) are reported to have contributed to failure through wear, fatigue fracture and osteolysis2, 3, 4, 5. The DURALOC Acetabular Cup has a minimum thickness of 6mm for the polyethylene liner (sizes 48- 74mm), comfortably above the thicknesses at which some types of failures have been shown to occur.

  • A machined inner diameter

    The DURALOC Acetabular Cup employs a machined inner diameter to improve the fit of the polyethylene liner to the inner surface of the metal shell. By avoiding a polished inner surface, the inner diameter form (roundness) is held to precise tolerances, thereby improving the congruency of the liner/shell interface. 

  • Secure liner location

    The sensor-ring locking mechanism in the metal shell secures the polyethylene liner. It conforms to dimensional variances with the polyethylene liner caused by creep deformation and helps eliminate the risk of liner dissociation. In addition, six anti-rotation devices (ARDs) located within the shell maintain liner/cup orientation, control rotation and allow the liner to be placed in any position (as required to achieve joint stability). Together, these two features work to help potentially reduce micromotion at the liner/shell interface.

  • Total congruency

    The DURALOC Acetabular Cup was designed to achieve total congruency between the polyethylene liner and the metal shell. Loading from the femoral head is spread evenly across the load bearing area of the liner/shell interface, avoiding loads at the rim of the metal shell/polyethylene liner. The DURALOC shell is spherical and highly conforming to the polyethylene. There are no isolated stresses found around the rim, where excessive cyclic loading may produce cracks and failure of the polyethylene.

Supporting Documentation

Resources

References

1. Orthopaedic Data Evaluation Panel. ODEP product ratings. Latest ODEP ratings can be found at www.odep.org.uk [Accessed 16/01/2019].
2. Berry, D.J.; Barnes, C.L.; Scott, R.D.; Cabanela, M.E. and Poss, R.: Catastrophic Failure of the Polyethylene Liner of Uncemented Acetabular Components. Journal of Bone and Joint Surgery, 76-B, No 4, 1994. 
3. Collier, J.P.; Mayor, M.B.; Jensen, R.E.; Surprenant, V.A.; Surprenant, H.P.; McNamara, J.L. and Belec, L.: Mechanisms of Failure of Modular Prostheses. Clinical Orthopaedics and Related Research, 285, 1992. 
4. Astion, D.J.; Saluan, P.; Stulberg, B.N.; Rimnac, C.M. and Li, S.: The Porous-Coated Anatomic Total Hip Prosthesis: Failure of the Metal-Backed Acetabular Component. Journal of Bone and Joint Surgery, 77-A, No.5, 1992. 
5. Ries, M.D.; Collis, D.K. and Lynch, F.: Separation of the Polyethylene Liner from Acetabular Cup Metal Backing. Clinical Orthopaedics and Related Research, 282, 1992. 

Indication Statement

For product details such as indications, contraindications, warnings and precautions please consult the IFU.
 

111568-190410