We report a study of 85 Symax femoral stems that were followed at regular intervals with radiographs at 6, 12, 24 and 36 months. The radiological migration of each stem was measured using the computer-assisted EBRA-FCA method. In 30 cases in which the EBRA method did not provide a complete measurement another computer-assisted method (Roman version 1.7) was employed. In all cases the distal migration of the stems was minimal, The threshold migration value used to define the stability of a stem was 1.5 mm at 24 months. The mean migration within the first two years was -0.17 mm (+/- 0.3) at 6 months, -0.31 mm (+/- 0.4) at 12 months and -0.45 mm (+/- 0.5) at 24 months. Only two cases exceeded the threshold limit of 1.5 mm at the two-year follow-up, but both values were lower than 2 mm. In the 25 cases which reached three-year follow-up the mean distal migration was -0.84 (+/-0.7). In four of them the subsidence exceeded 1.5 mm, but only one exceeded 2 mm. These data represent a positive predictive factor for the minimal risk of future aseptic loosening.
WitvoetJ.. Critiques des methods d'évaluation de la chirurgie prothétique de la hanche.Conferences d'enseignement de la S.O.F.C.O.T.1995; 52: 11–22.
2.
FreemanM.A., Plante-BordeneuveP.. Early migration and late aseptic failure of proximal femoral prostheses.Bone Joint Surg Br1994; 76: 432–8.
3.
WalkerP.S., MaiS.F., CobbA.G., BentleyG., HuaJ.. Prediction of clinical outcome of THR from migration measurements on standard radiographs. A study of cemented Charnley and Stanmore femoral stems.J Bone Joint Surg Br1995; 77: 705–14.
4.
SelvikG.. Roentgen stereophotogrammetry: A method for the study of the kinematics of the skeletal system.Acta Orthop Scand Suppl1989; 232: 1–51.
5.
KarrholmJ., BorssenB., LowenhielmG., SnorrasonF.. Does early micromotion of femoral stem prostheses matter? 4-7-year stereoradiographic follow-up of 84 cemented prostheses.J Bone Joint Surg Br1994; 76: 912–7.
6.
MalchauH., KarrholmJ., WangY.X., HerbertsP.. Accuracy of migration analysis in hip arthroplasty. Digitized and conventional radiography, compared to radiostereometry in 51 patients.J Bone Joint Surg Br1996; 78: 1–3.
7.
NistorL., BlahaJ.D., KjellstromU., SelvikG.. In vivo measurements of relative motion between an uncemented femoral total hip component and the femur by roentgen stereophotogrammetric analysis.Clin Orthop Relat Res1991; 269: 220–7.
8.
OrnsteinE., FranzenH., JohnssonR., SandquistP., StefansdottirA., SundbergM.. Migration of the acetabular component after revision with impacted morselized allografts: a radiostereometric two-year follow-up analysis of 21 cases.Acta Orthop Scand1999; 70: 338–42.
9.
CianciR., BaruffaldiF., FabbriF., AffatatoS., ToniA., GiuntiA.. A computerized system for radiographical evaluation in total hip arthroplasty.Comput Methods Programs Biomed1995; 46: 233–43.
10.
KrismerM., StöcklB., FischerM., BauerR., MayrhoferP., OgonM.. Early migration predicts late aseptic failure of hip socket.J.Bone Joint Surg Br1996; 78-B: 422–6.
11.
IlchmannT., FranzenH., MjobergB., WingstrandH.. Measure ment accuracy in acetabular cup migration. A comparison of four radiological methods versus roentgen sterophotogrammetric analysis.J Arthroplasty1992; 7: 121–7.
12.
IlchmannT.. Radiographic assessment of cup migration and wear after hip replacement.Acta Orthop Scand Suppl1997276: 1–26.
13.
BiedermannR., KrismerM., StocklB., MayrhoferP., OrnsteinE., FranzenH.. Accuracy of EBRA-FCA in the measurement of migration of femoral components of total hip replacement. Einzel-Bild-Roentgen-Analyse-femoral component analysis.J Bone Joint Surg Br1999; 81: 266–72.
14.
KrismerM., BiedermanR., StöckelB., FischerM., BauerR., HaidC.. The prediction of failure of the stem in THR by measurement of early migration using EBRA-FCA.J Bone Joint Surg Br1999; 81-B: 273–80.
15.
EingartnerC., HeigeleT., DieterJ., WinterE., WeiseK.. Long-term results with the BiCONTACT system–aspects to investigate and to learn from.Int Orthop2003; 27 Suppl 1: S11–5.
16.
Van GoethemC., PflugerD.H.. Assessment of early migration and clinical evaluation of a cemented femoral stem.Acta Ortho Belg2005; 71: 555–64.
17.
RadlR., HungerfordM., MaternaW., RehakP., WindhagerR.. Higher failure rate and stem migration of an uncemented femoral component in patients with femoral head osteonecrosis than in patients with osteoarthrosis.Acta Orthop2005; 76: 49–55.
18.
KlestilT., BiedermannR., KrugerA., GfollerP., SchoelzW., RanggerC., KrismerM., BlauthM.. Cementless hemiarthroplasty in femoral neck fractures: Evaluation of clinical results and measurement of migration by EBRA-FCA.Arch Orthop Trauma Surg2006; 24: 380–6.
19.
IlchmannT., EingartnerC., HegerK., WeiseK.. Femoral subsidence assessment after hip replacement: An experimental study.Ups J Med Sci2006; 111: 361–9.
20.
InceA., LermannJ., GöbelS., WollmerstedtN., HendrichC.. no increased stem subsidence after arthroplasty in young patients with femoral head osteonecrosis: 41 patients followed for 1–9 years.Acta Orthop2006; 77: 866–70.
21.
KarrholmJ., SnorrasonF.. Subsidence, tip, and hump micro-movements of noncoated ribbed femoral prostheses.Clin Orthop Relat Res1993; 287: 50–60.
22.
BeauleP.E., KrismerM., MayrhoferP., WannerS., Le DuffM., MattesichM., StoecklB., AmstutzH.C., BiedermannR.. EBRA-FCA for measurement of migration of the femoral component in surface arthroplasty of the hip.J Bone Joint Surg Br2005; 87: 741–4.
23.
EinsiedelT., GebhardF., BregolatoI., HiemeierA., KinzlL., SchultheissM.. Proximal cement fixation in total hip arthroplasty: first results with a new stem design.Int Orthop2008; 32: 295–306.
24.
GeerdinkC.H., GrimmB., VenckenW., HeyligersI.C., ToninoA.J.. The determination of linear and angular penetration of the femoral head into the acetabular component as an assessment of wear in total hip replacement. A comparison of four computer-assisted methods.J bone Joint Surg Br2008; 90-B: 839–46.
