The study was designed to evaluate the effect of different loading configurations on stem and bone stresses in simulated total hip arthroplasty. The traditional experiment design of loading the model through the head of the prosthesis by the resultant joint force was compared with a more realistic model which included an abductor strap to simulate the abductor muscle force. In addition, an alternative experiment design was evaluated in which a loading arm was clamped directly on to the head of the prosthesis. The results show that loading the model by the resultant joint force not only changes the magnitude of the stresses but also the stress distribution compared to the abductor muscle model. The new experiment design closely approximates stresses seen in the abductor muscle model below the lesser trochanter. In the proximal region, the stresses are increased on the medial side and decreased on the lateral side. The advantages of the proposed loading model are: (a) easy and reproducible set-up and alignment is facilitated, (b) different positions of the femur (flexion, extension) can be simulated and (c) a more realistic stress distribution and magnitude is achieved.
Get full access to this article
View all access options for this article.
References
1.
CharnleyJ.Fracture of femoral prostheses in total hip replacement. Clin. Orthop. Related Res., 1975, 111, 105–120.
2.
KavanaghB. F.FitzgeraldR. H.Clinical and roentgenographic assessment of total hip arthroplasty. Clin. Orthop. Related Res., 1987, 193, 113–140.
3.
DallD. M.LearmonthI. D.MilesA.A comparison of first and second generation Charnley femoral stems in total hip replacement. Fifty-fifth Annual Meeting of the American Academy of Orthopaedic Surgeons, Atlanta, Georgia, 1988, paper 189.
4.
MilesA. W.DallD. M.RivarolaM.A study of anteroposterior load transfer in total hip replacement using a modelling technique. Engng Med., 1983, 12, 113–115.
5.
InmanV. T.Functional aspects of the abductor muscles of the hip. J. Bone Jt Surg., 1947, 29, 607–619.
6.
McLeishR. D.CharnleyJ.Abduction forces in the one-legged stance. J. Biomechanics, 1970, 3, 191–209.
7.
PaulJ. P.PoulsonJ.The analysis of forces transmitted by joints in the human body. Proceedings of the Fifth International Conference on Experimental stress analysis, Udine, 1974, pp. 3. 34–3.42.
8.
PauwelsF. R.Der Schenkelhalsbruch, ein mechanisches Problem. Z. Orthop. Chir., 1935, 63 (Suppl.), 1935.
9.
WilliamsJ. F.SvenssonN. L.A force analysis of the hip joint. Biomed. Engng, 1968, 3, 365–370.
10.
ElsonR. A.CharnleyJ.The direction of the resultant force in total prosthetic replacement of the hip joint. Med. and Biol. Engng, 1968, 6, 19–27.
11.
AndriacchiT. P.GalanteJ. O.BelytschkoT. B.HamptonS.A stress analysis of the femoral stem in total hip prostheses. J. Bone Jt Surg., 1976, 58A, 618–624.
12.
HuiskesR.Biomechanics of bone—implant interactions. In Frontiers of biomechanics (Eds Schmid-SchoenbeinG. W.WooS. L.-Y.ZweifachB. W.), 1986, pp. 245–262 (Springer-Verlag, New York, Berlin, Heidelberg, Tokyo).
13.
LanyonL. E.PaulI. L.RubinC. T.ThrasherE. L.DeLauraR.RoseR. M.RadinE. I.In vivo measurements from bone and prosthesis following total hip replacement. An experimental study in sheep. J. Bone Jt Surg., 1981, 63A, 989–1001.
14.
RubinC. T.LanyonL. E.Regulation of bone formation by applied dynamic loads. J. Bone Jt Surg., 1984, 66A, 397–402.
15.
TurnerT. M.SummerD. R.UrbanR. M.RiveroD. P.GalanteJ. O.A comparative study of porous coatings in a weight-bearing total hip-arthroplasty model. J. Bone Jt Surg., 1986, 68A, 1396–1409.
16.
OhI.HarrisW. H.Proximal strain distribution in the loaded femur. J Bone Jt Surg., 1978, 60A, 75–85.
17.
ZhouX. M.WalkerP. S.RobertsonD. D.Effect of press-fit femoral stems on strains in the femur. J. Arthroplasty, 1990, 5, 71–82.
18.
WeinansH.HuiskesR.GrootenboerH.The mechanical effects of fibrous tissue interposition at the cement-bone interface in THA. In Transactions of the Thirty-fourth Annual Meeting of the Orthopaedic Research Society, Atlanta, Georgia, 1988, p. 224.
19.
CrowninshieldR. D.BrandR. A.JohnstonR. C.MilroyJ. C.An analysis of femoral component stem design in total hip arthroplasty. J. Bone Jt Surg., 1980, 62A, 68–78.
20.
RohlmannA.MössnerU.BergmannG.KölbelR.Finite-element-analysis and experimental investigation of stresses in a femur. J. Biomed. Engng, 1982, 4, 241–246.
21.
PageA.JastyM.BragdonC.ItoK.HarrisW. H.Alterations in femoral and acetabular bone strains immediately following cementless total hip arthroplasty—an in vitro canine study. J. Orthop. Res., 1991, 9, 738–748.
22.
FinlayJ. B.RorabeckC. H.BourneR. B.TewW. M.In vitro analysis of proximal femoral strains using PCA femoral implants and a hip-abductor muscle simulator. J. Arthroplasty, 1989, 4, 335–345.
23.
FinlayJ. B.ChessD. G.HardieW. R.RorabeckC. H.BourneR. B.An evaluation of three loading configurations for the in vitro testing of femoral strains in total hip arthroplasty. J. Orthop. Res., 1991, 9, 749–759.
24.
Transactions of the Thirty-third Annual Meeting of the Orthopaedic Research Society, San Francisco, California, 1987.
25.
Transactions of the Thirty-fourth Annual Meeting of the Orthopaedic Research Society, Atlanta, Georgia, 1988.
26.
Transactions of the Thirty-fifth Annual Meeting of the Orthopaedic Research Society, Las Vagas, Nevada, 1989.
27.
Transactions of the Thirty-sixth Annual Meeting of the Orthopaedic Research Society, New Orleans Louisiana, 1990.
28.
Transactions of the Thirty-seventh Annual Meeting of the Orthopaedic Research Society, Anaheim, California, 1991.
29.
BursteinA. H.ReillyD. M.MartensM.Ageing of bone tissue: Mechanical properties. J. Bone Jt Surg., 1976, 58A, 82.
30.
GibbonsD. F.Biomedical materials. In Handbook of engineering in medicine and biology (Eds FlemingD. G.FeinbergB. N.), 1976, p. 254 (CRC Press, Boca Raton, Florida).
31.
EvansF. G.VincentelliA.Relation of the compressive properties of human cortical bone to histological structure and calcification. J. Biomechanics, 1974, 7, 1.
32.
SchmotzerH.FitzpatrickJ.MooreT.DallD. M.GendlerE.Compressive properties of various human allograft bone preparations. In Transactions of the Fourth World Bio-materials Congress, Berlin, 1992.
33.
SchmotzerH.MittlmeierTh.PlitzW.Surface stress analysis of polyethylene total hip replacement acetabular cups under quasistatic loading. VDI Berichte, 1985, 181–193.
34.
HumphreysP. K.OrrJ. F.BahraniA. S.Testing of total hip replacements: Endurance tests and stress measurements. Part 2: Stress measurements. Proc. Instn Mech. Engrs, Part H, 1990, 204(H1), 35–41.
