Wolff, R. (Ricarda) (2019) Radiological evaluation of risk factors for early subsidence of cementless hip endoprosthesis stems of type Excia T®. thesis, Medicine.
Full text available on request.Abstract
Background: In end-staged coxarthrosis a surgical intervention in the form of total hip arthroplasty (THA) constitutes the most effective treatment (1). Implant component loosening after THA is reported to be a rare complication with a prevalence of less than 10 % after 10 years (2). Yet, prosthesis stem subsidence, in particular, after cementless implantation is investigated within several studies. The Excia T® stem design is used for cementless THA in the University Hospital for Orthopaedics and Trauma Surgery Medical Campus Pius Hospital. A notable patient number suffered from early stem subsidence after surgery subsequently necessitating revision surgery in many cases. A correlation between the bony implant site configuration and this early Excia T® stem subsidence is assumed. Objective: This study aimed to get more insight into the Excia T® stem subsidence. By evaluating the femoral bone configuration on preoperative radiographs, it was investigated if it was possible to predict preoperatively whether a certain femoral bone configuration may constitute a risk factor for early Excia T® stem subsidence. Methods: A retrospective evaluation was conducted by analysing preoperative radiographs from 443 patients undergoing primary THA using the cementless Excia T® stem between January 2016 and April 2018 in Pius Hospital. Defined radiographic parameters, including the Dorr classification, Bombelli classification, Singh index, Cortical thickness index, Canal-tocalcar ratio, Medial cortex ratio and Centrum-collum-diaphyseal angle, were determined and the results were correlated with early stem subsidence occurrence. Differences in the femoral bone configuration of hips with subsidence in comparison to those with stable implants were investigated. Non-parametric tests, including the Mann-Whitney U test, Fisher’s exact test, Chisquare test and Kruskal-Wallis H test, were used for the statistical analysis. Results: Early stem subsidence occurred in 22 of 443 investigated hips (4.97 %), requiring revision surgery in 59.09 % of the subsided hips (n = 13). Hips with stem subsidence were significantly more often classified as Dorr type A femurs with a proportion of 68.2 % compared to 43.5 % in patients with stable implants (p = .028). Conversely, Dorr type B was significantly higher in the non-subsidence group (p = .047). Further, significant differences among the three Dorr types concerning the Cortical thickness index, Canal-to-calcar ratio and Medial cortex ratio were assessed (all p < .001). For the remaining radiographic parameters no significant differences were found. Conclusion: The subsidence incidence for the Excia T® stem with revision surgery necessity is remarkably high in Pius Hospital. The concerned hips were significantly more often classified to Dorr type A. This is consistent with the assumption that a narrowing medullary canal restricts the stable prosthesis fit due to the special stem geometry with proximal anchoring technique. Thus, a proximal femoral configuration of Dorr type A may constitute a hint on an increased early subsidence risk for the Excia T® stem, but further investigations are required.
| Item Type: | Thesis (Thesis) |
|---|---|
| Supervisor name: | Faculty supervisor and Stevens, Dr. M. and Orthopaedic Department University Medical Center Groningen ( |
| Supervisor name: | Second supervisor: and Maus, Prof. Dr. U. and Klinik für Orthopädie und Unfallchirurgie Pius Hospital Olde |
| Faculty: | Medical Sciences |
| Date Deposited: | 25 Jun 2020 10:47 |
| Last Modified: | 25 Jun 2020 10:47 |
| URI: | https://umcg.studenttheses.ub.rug.nl/id/eprint/808 |
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