A cohort of 35 explanted acetabular sockets was examined to ascertain the direction of penetration. The penetration relative to the open face of the socket was measured using the shadowgraph method and the corresponding anatomical direction was then deduced using anterior-posterior radiographs. A median anatomical penetration direction of 17.5° lateral to the sagittal plane was found (range 27° medial to 44° lateral). These observations confound explanation through analysis of the motion and loading of the hip joint.
ElfickA.P.D., HallR.M., PinderI.M., UnsworthA.. The effect of socket design, materials and liner thickness on the wear of the PCA total hip replacement. Proc Instn Mech Engrs: Part H2001; 215: 447–57.
2.
HeekinR.D., CallaghanJ.J., HopkinsonW.J., SavoryC.G., XenosJ.S.. The porous-coated anatomic total hip prosthesis, inserted without cement. J Bone Joint Surg (Am)1993; 75-A: 77–91.
HallR.M., SineyP., UnsworthA., WroblewskiB.M.. Observations on the direction of wear in Charnley sockets retrieved at revision surgery. J Bone Joint Surg (Br)1998; 80-B: 1067–72.
5.
ElsonR.A., CharnleyJ.. The direction of the resultant force in total prosthetic replacement of the hip joint. Med Biol Eng1968; 6: 19–27.
6.
BergmannG., GraichenF., RohlmannA.. Hip joint loading during walking and running, measured in two patients. J Biomech1993; 26: 969–90.
7.
MurrayD.W., O'ConnorJ.J.. Superolateral wear of the acetabulum. J Bone Joint Surg (Br)1998; 80-B: 197–200.
8.
McLeishR.D., SkoreckiJ.. Analysis of wear in a spherical joint. Proc Instn Mech Engrs1968; 183: 389–94.
