Cementless femoral hip stems crucially depend on the initial stability to ensure a long survival of the prosthesis. There is only a small margin between obtaining the optimal press fit and a femoral fracture. The incidence of an intraoperative fracture is reported to be as high as 30% for revision surgery. The aim of this study is to assess what information is contained in the acoustic sound produced by the insertion hammer blows and explore whether this information can be used to assess optimal seating and warn for impeding fractures. Acoustic measurements of the stem insertion hammer blows were taken intra-operatively during 7 cementless primary (Wright Profemur Primary) and 2 cementless revision surgeries (Wright Profemur R Revision). All surgeries were carried out by the same experienced surgeon. The sound was recorded using 6 microphones (PCB 130E2), mounted at a distance of approximately 1 meter from the surgical theater. The 7 primary implants were inserted without complication, 1 revision stem induced a fracture distally during the insertion process. Two surgeons were asked to listen independently to the acoustic sounds post-surgery and to label the hits in the signal they would associate with either a fully fixated implant or with a fracture sound. For 3 out of 7 primary measurements the data was labeled the same by the two surgeons, 4 were labeled differently or undecided and both indicated several hits that would be associated with fracture for the fractured revision case. The acquired time signals were processed using a number of time and frequency domain processing techniques.Introduction
Materials and Methods
The aim of our review was to assess (health related) quality of life ((HR)QoL) after one-stage or two-stage revision for prosthetic joint infection (PJI). Although it is generally accepted that staged revisions are very strenuous for patients, little is known about the (HR)QoL after these procedures. We compared (HR)QoL scores with normative population scores to assess the magnitude of this problem. Two authors performed a computerized systematic search in Embase, Cochrane and Pubmed. We included articles that reported: validated (HR)QoL questionnaires, one-stage or two-stage revision for PJI after total hip arthroplasty (THA), a minimum follow-up of 24 months and a minimum of ten patients. Methodological quality of all papers was assessed using the MINORS score. The systematic review was conducted according to the PRISMA statement. The search produced 11195 hits. After selection, based on title and abstract, 18 full text papers were reviewed. Six articles were excluded. Twelve papers were selected for final assessment. All papers described two-stage revisions. The mean MINORS score for these studies was 9.8, indicating moderate study quality. Seven articles reported WOMAC scores, with a total of 185 patients (74% response rate) having a mean general score of 73, with a mean follow-up of 65 months. The normative total WOMAC score for the general population (age 60–64) is 82.9, with a score of 100 being the best possible outcome. Four articles described Short Form 36 (SF-36) results on a total of 159 patients (71.9% response rate). In these studies the physical component score (PCS) of the SF-36 was on average 39.6 and the mental component score (MCS) was on average 50.9, with a mean follow-up of 41 months. Normative data for the US population (age 55–64) are a PCS of 47.2 and an MCS of 51.8. Four articles reported Short Form 12 (SF-12) scores on a total of 138 patients, with a mean PCS of 33.6 and a mean MCS of 51.7, with a mean follow up of 72.5 months. Normative data for the Dutch population (age 55–65) are a PCS of 48.3 and an MCS of 52.8. A score of 100 represents best possible health for both SF questionnaires. Patients that underwent two-stage revision for hip PJI have substantially lower (physical component) (HR)QoL scores, when compared to the general population.
Treatment of Paprosky type 3A and 3B defects in revision surgery of a hip arthroplasty is challenging. In previous cases such acetabular defects were treated with massive structural allograft bone reconstructions using cemented all-polyethylene cups. In our department we started using custom made triflanged cups to restore the articulation of the hip. The triflanged cups were designed on the basis of CT-image analysis. We are using a new type of implant construction technique with additive technology. This is a production process consisting of ion beam sintering joining metal powder particles layer upon layer on the basis of a 3D model data. The production technique is similar to rapid prototyping manufacturing. 7 Patients have been treated with this new technique. The case studies will be presented with their clinical and radiographic follow-up. We think that additive technology is a breakthrough in treating this kind of severe acetabular defects.
