The Ganz acetabular reinforcement ring shows excellent long-term results when used as a primary implant: a retrospective analysis of two hundred and forty primary total hip arthroplasties with a minimum follow-up of twenty years
- 183 Downloads
The acetabular reinforcement ring with a hook (ARRH) has been designed for acetabular total hip arthroplasty (THA) revision. Additionally, the ARRH offers several advantages when used as a primary implant especially in cases with altered acetabular morphology. The implant facilitates anatomic positioning by placing the hook around the teardrop and provides a homogenous base for cementing the polyethylene cup. Therefore, the implant has been widely used in primary total hip arthroplasty at our institution. The present study reports the long-term outcome of the ARRH after a minimum follow-up of 20 years.
Two hundred and ten patients with 240 primary THAs performed between April 1987 and December 1991 using the ARRH were retrospectively reviewed after a minimum follow-up of 20 years. Twenty-three of 240 hips were lost to follow-up, 110 patients with 124 THAs had deceased without having a revision surgery performed. This left 93 hips for final evaluation. Of those, 75 hips were assessed clinically and radiographically after a mean follow-up of 23.1 years (range 21.1–26.1 years). In 18 cases, clinical and radiographic assessment was omitted because implant revision had been performed prior to the follow-up investigation. The primary endpoint was defined as revision for aseptic loosening.
Out of the 93 hips available for final evaluation, 14 hips were revised for aseptic loosening; another four were revised for other reasons (deep infection n = 2, recurrent dislocation n = 2). The survival probability of the cup was 0.96 (95% confidence interval 0.93–0.99) after 20 years with aseptic loosening as endpoint. Radiographic analysis of the surviving 75 hips showed at least one sign of radiographic loosening in 24 hips. The mean Merle d’Aubigne score increased from 8 points pre-operatively to 15 points at final follow-up (7.5 ± 1.8 vs 15.0 ± 2.3, p < 0.001). The mean HHS was 85 ± 14 at final follow-up. Radiographic loosening did not correlate with the clinical outcome.
The long-term results of the ARRH in primary THA are comparable to results with standard cemented cups and modern cementless cups. We believe that the ARRH is a versatile implant for primary THA, especially in cases with limited acetabular coverage and altered acetabular bone stock where the ARRH provides sufficient structural support for a cemented cup.
KeywordsGanz ring Acetabular reinforcement ring THA Aseptic loosening Revision
Compliance with ethical standards
The ethical committee of the canton of Bern, Switzerland approved the study (Ref.-No. KEK-BE: 265/2014).
Conflict of interest statement
The authors declare that they have no conflicts of interest.
- 2.Uchiyama K, Takahira N, Fukushima K, Yamamoto T, Moriya M, Itoman M (2010) Radiological evaluation of allograft reconstruction in acetabulum with Ganz reinforcement ring in revision total hip replacement. J Orthop Sci 15(6):764–771. https://doi.org/10.1007/s00776-010-1549-y CrossRefPubMedGoogle Scholar
- 7.Sirka A, Clauss M, Tarasevicius S, Wingstrand H, Stucinskas J, Robertsson O, Ochsner PE, Ilchmann T (2016) Excellent long-term results of the Muller acetabular reinforcement ring in primary total hip arthroplasty: a prospective study on radiology and survival of 321 hips with a mean follow-up of 11 years. Acta Orthop 87(2):100–105. https://doi.org/10.3109/17453674.2015.1103607 CrossRefPubMedGoogle Scholar
- 9.Siebenrock KA, Tannast M, Kim S, Morgenstern W, Ganz R (2005) Acetabular reconstruction using a roof reinforcement ring with hook for total hip arthroplasty in developmental dysplasia of the hip-osteoarthritis minimum 10-year follow-up results. J Arthroplast 20(4):492–498. https://doi.org/10.1016/j.arth.2004.09.045 CrossRefGoogle Scholar
- 18.Goodman SB, Adler SJ, Fyhrie DP, Schurman DJ (1988) The acetabular teardrop and its relevance to acetabular migration. Clin Orthop Relat Res (236):199–204Google Scholar
- 22.Müller MEJH (1989) Total hip reconstruction. In: Evarts CM (ed) Surgery of the musculoskeletal system, 2nd edn. Churchill Livingstone, New YorkGoogle Scholar
- 25.Cox DR (1972) Regression models and life-tables. J R Stat Soc Ser B Methodol 34(2):187–220Google Scholar
- 29.Eskelinen A, Remes V, Helenius I, Pulkkinen P, Nevalainen J, Paavolainen P (2005) Total hip arthroplasty for primary osteoarthrosis in younger patients in the Finnish arthroplasty register. 4,661 primary replacements followed for 0-22 years. Acta Orthop 76(1):28–41. https://doi.org/10.1080/00016470510030292 CrossRefPubMedGoogle Scholar
- 30.Corten K, Bourne RB, Charron KD, Au K, Rorabeck CH (2011) What works best, a cemented or cementless primary total hip arthroplasty?: minimum 17-year followup of a randomized controlled trial. Clin Orthop Relat Res 469(1):209–217. https://doi.org/10.1007/s11999-010-1459-5 CrossRefPubMedGoogle Scholar
- 35.Tarasevicius S, Kesteris U, Robertsson O, Wingstrand H (2006) Femoral head diameter affects the revision rate in total hip arthroplasty: an analysis of 1,720 hip replacements with 9-21 years of follow-up. Acta Orthop 77(5):706–709. https://doi.org/10.1080/17453670610012872 CrossRefPubMedGoogle Scholar
- 37.Zijlstra WP, De Hartog B, Van Steenbergen LN, Scheurs BW, Nelissen R (2017) Effect of femoral head size and surgical approach on risk of revision for dislocation after total hip arthroplasty. Acta Orthop 88(4):395–401. https://doi.org/10.1080/17453674.2017.1317515 CrossRefPubMedPubMedCentralGoogle Scholar