In 2006 the standard prosthesis for hip hemiarthroplasty in our unit was changed from the traditional Thompson prosthesis used for over 20 years to the monobloc Exeter Trauma Stem (ETS). The principle anticipated advantages were ease of stem implantation, improvement of orientation positioning and a consistency with modern proven femoral THR stem design.
All patients selected for hemiarthroplasty replacement for a displaced subcapital fracture of the hip were eligible for inclusion. Failed previous surgical cases were excluded.
The last 100 Thompson’s prostheses used before and the first 100 Exeter Trauma Stems undertaken after the changeover date were studied. Outcomes measured included surgical complications including infection, dislocation, fracture, necessity to ream etc. and technical adequacy of implant positioning based upon post-operative radiographs. Surgeon grade was recorded. There were no changes in surgical personnel.
206 consecutive patients were included in the study (age range 76–96); 67 men and 139 women. Data were collected prospectively as part of a comprehensive hip fracture audit.
Initial results show that the rate of surgical complications is similar in both prosthesis groups. Radiographs demonstrate the presence of a learning curve in the use of the new prosthesis. On six occasions after December 2006 the Thompson prosthesis was used – this was due to unavailability of ETS prosthesis or where a very large femoral head (56mm) was required.
The introduction of the ETS for hip hemiarthroplasty was successful. Initial conversion problems involved maintaining sufficient stock of the most commonly used size of prosthesis. Advantages were a low dislocation rate despite the greater potential for erroneous implant version and a reduction in the amount of femoral preparation required including reaming. Limitations of this study are the lack functional outcome and long term survivorship analysis.
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