EBRA Migration Patterns of the Plasmacup with Ceramic or Polyethylene Inserts: A Randomised Study

Abstract

Aim: In this prospective randomised study, the influence of different bearing materials on migration and wear was measured and their effect on the function of the artificial joint and the patient outcome was investigated. Mid-term results were recorded so that recommendations can be made on the use of certain bearings, which minimise wear and thus the danger of subsequent aseptic loosening. Method: Sixty-six patients met the inclusion criteria and were willing to take part in the study. These patients were randomised to 2 groups. All of them had total hip arthroplasty with implantation of a cementless Bicontact stem and Plasmacup using a cementless press-fit technique. Thirty-five of these patients were given a ceramic-ceramic bearing and 31 patients a ceramic-polyethylene bearing (gamma sterilised/nitrogen environment). At the most recent follow-up, they underwent detailed clinical and radiological examination and evaluation by means of the Harris Hip Score, Hannover function questionnaire and single-film X‐ray analysis (EBRA). Results: The overall follow-up rate was 65.2 % (43 of 66) and the mean follow-up period was 8.1 (7.1 - 9.2) years. The median Harris Hip Score at the time of follow-up was 90.1 (58.7 - 99.9) points. The average Hannover function score was 87.14 % (63.9 - 100). In 4 of 66 cases (6.1 %) there was a tendency for the Plasmacup to subsidence in the first postoperative months that was slight but detectable by EBRA; however, this stopped subsequently. This primary subsidence was independent of the chosen bearing material. No significant difference in the clinical and radiological parameters was found between the two groups. Conclusion: The very good results with regard to the rate of loosening confirm the press-fit cup fixation concept. The study shows a similar medium-term result for the ceramic-ceramic and ceramic-polyethylene bearing so that use of both bearings can continue to be recommended. Only long-term studies with sufficiently large numbers of patients will be able to show whether significant differences can be detected between the two slide bearings with regard to wear and migration behaviour and so that a recommendation can be given to the surgeon.

Key words

total hip arthroplasty - press‐fit cup - EBRA - ceramic on ceramic - ceramic on polyethylene bearing

References

• 1 Amstutz H, Campbell P, Kossovsky N, Clarke I. Mechanism and clinical significance of wear debris-induced osteolysis.  Clin Orthop. 1992;  276 7-18
• 2 Borlin N, Rohrl S, Bragdon C. RSA wear measurements with or without markers in total hip arthroplasty.  J Biomech. 2006;  39 1641-1650
• 3 Dowd J, Sychterz C, Young A, Engh C. Characterization of long-term femoral-head-penetration rates.  J Bone Joint Surg [Am]. 2000;  82 1102-1107
• 4 Dumbleton J, Manley M, Edidin A. A literature review of the association between wear rate and osteolysis in total hip arthroplasty.  J Arthroplasty. 2002;  17 649-661
• 5 Harris W. Traumatic arthritis of the hip after dislocation and acetabular fractures: treatment by arthroplasty. An end-result study using a new method of result-evaluation.  J Bone Joint Surg [Am]. 1969;  51 737-755
• 6 Hendrich C, Blanke M, Sauer U, Rader C, Eulert J. Klinische Erfahrungen und Migrationsanalyse - Plasmacup. Stuttgart; Thieme Verlag 2000: 26-34
• 7 Ilchmann T. Radiographic assessment of cup migration and wear after hip replacement.  Acta Orthop Scand Suppl. 1997;  276 1-26
• 8 Ilchmann T, Franzen H, Mjoberg B, Wingstrand H. Measurement accuracy in acetabular cup migration, a comparison of four radiologic methods versus roentgen stereophotogrammetric analysis.  J Arthroplasty. 1995;  10 636-642
• 9 Ilchmann T, Neher S, Maurer F, Weise K. Modes of failure of a threaded acetabular cup: a radiographic study with EBRA of 42 revised cups.  Int Orthop. 2006;  8 18-25
• 10 Kadoya Y, Kobayashi A, Ohashi H. Wear and osteolysis in total joint replacements.  Acta Orthop Scand Suppl. 1998;  278 1-16
• 11 Knahr K, Kryspin-Exner I, Jagsch R, Freilinger W, Kasparek M. [Evaluating the quality of life before and after implantation of a total hip endoprosthesis] Beurteilung der Lebensqualität vor und nach Implantation einer Hüfttotalendoprothese.  Z Orthop Ihre Grenzgeb. 1998;  136 321-329
• 12 Krismer M, Bauer R, Tchupik J, Mayrhofer P. EBRA: a method to measure migration of acetabular components.  J Biomechanics. 1995;  27 1225-1236
• 13 Krismer M, Stöckl B, Fischer M, Baur R, Mayrhofer P, Ogon M. Early migration predicts late aseptic failure of hip sockets.  J Bone Joint Surg [Br]. 1996;  78 422-426
• 14 Marchetti P, Binazzi R, Vaccari V, Girolami M, Morici F, Silvello L. Long-term results with cementless Fitek (or Fitmore) cups.  J Arthroplasty. 2005;  20 730-737
• 15 Mochida Y, Boehler M, Salzer M, Bauer T. Debris from failed ceramic-on-ceramic and ceramic-on-polyethylene hip prostheses.  Clin Orthop. 2001;  389 113-125
• 16 Morscher E, Widmer K, Bereiter H, Elke R, Schenk R. [Cementless socket fixation based on the “press-fit” concept in total hip joint arthroplasty] Zementfreie Pfannenverankerung nach dem „Press-Fit-Konzept“ bei der Totalprothesen-Arthroplastik der Hüfte.  Acta Chir Orthop Trauma. 2002;  69 8-15
• 17 Roth A, Winzer T, Sander K, Anders J, Venbrocks R. Press fit fixation of cementless cups: how much stability do we need indeed?.  Arch Orthop Trauma Surg. 2006;  126 77-81
• 18 Schmalzried T, Shepherd E, Dorey F, Jackson W, de la Rosa M, Martell J. Wear is a function of use, not time.  Clin Orthop. 2000;  381 36-46
• 19 Sychterz C, Engh C, Yang A. Analysis of temporal wear patterns of porous-coated acetabular components: distinguishing between true wear and so-called bedding-in.  J Bone Joint Surg [Am]. 1999;  81 821-830
• 20 Wilkinson J, Gordon A, Stockley I. Experiences with the Plasmacup - early stability, wear, remodeling and outcome.  Int Orthop. 2003;  27 (Suppl 1) 16-19
• 21 Zhou Z K, Li M G, Borlin N, Wood D J, Nivbrant B. No increased migration in cups with ceramic-on-ceramic bearing: an RSA study.  Clin Orthop Relat Res. 2006;  448 39-45