Cup positioning and its effect on polyethylene wear of vitamin E- and non-vitamin E-supplemented liners in total hip arthroplasty: radiographic outcome at 5-year follow-up

Autor: Baghdadi, Josef, Alkhateeb, Shareef, Roth, Alexander, Jäger, Marcus, Busch, A., Landgraeber, Stefan, Serong, S., Haversath, Marcel, von Wasen, A., Windhagen, H., Flörkemeier, T., Budde, S., Kubilay, J., Noll, Y., Delank, K.S., Willburger, R., Dücker, M., Wilke, A., Hütter, F.
Rok vydání: 2022
Předmět:
Zdroj: Archives of Orthopaedic and Trauma Surgery. 143:1679-1688
ISSN: 1434-3916
DOI: 10.1007/s00402-022-04424-2
Popis: Background Aseptic loosening remains a challenging problem after total hip arthroplasty. Accurate cup placement and supplementation of antioxidants in acetabular liners might reduce material failure rates. The aim of this study is to assess the effect of the cup position on the wear behaviour of UHMWPE-XE and UHMWPE-X liners in vivo using virtual radiographs. Methods We conducted a prospective, randomized, controlled, multicenter trial. Clinical data of 372 probands were analyzed. Anteroposterior pelvic X-rays of 324 patients immediately postoperatively and after 1 and 5 years were evaluated by the RayMatch® analysis software regarding cup position and wear behaviour. Results Mean cup anteversion was 20.3° (± 7.4) and inclination was 41.9° (± 7.0) postoperatively. 62.3% of all patients had an anteversion and inclination within the Lewinnek safe zone. Anterior and anterolateral approaches led to significantly higher cup anteversion compared to lateral approaches (27.3° ± 5.5; 20.9° ± 7.2; 17.5° ± 6.6; p p = 0.001, respectively). Mean anteversion increased to 24.6° (± 8.0) after 1 year (p p = 0.012) and this was amplified when inclination angles were ≥ 50° (23.6 µm/year ± 12.8 vs. 38.0 µm/year ± 22.7, p = 0.062). Conclusion Anterior approaches lead to the highest inaccuracy of cup placement, but cup positioning outside the Lewinnek safe zone does not necessarily cause higher dislocation rates. Moreover, mean anteversion increased by approximately four degrees within the first year after operation, which is expected to be functional due to a regularization of pelvic tilt after intervention. Mid-term wear rates of UHMWPE-X and UHMWPE-XE liners are comparable, but steep cup positions lead to significantly increased polyethylene wear. In summary, a re-evaluation of target zones for intraoperative cup positioning might be considered. In the long-term reduced oxidative embrittlement could lead to superior wear behaviour of vitamin E-blended liners.
Databáze: OpenAIRE
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