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Figure 1: 45-year old patient complaining of increasing pain located in the right hip. The patient had a history of trauma in his adolescence suffering from a fracture of his right acetabulum. After initial open reduction and plate osteosynthesis he developed a posttraumatic osteoarthritis. A THA was performed in 1987 with a postoperative uneventful course. The overweighted patient (BMI: 30.9 kg/m2) had a history of arterial hypertension and he smoked heavily. Additionally he had a history of prostate carcinoma and alcohol abuse. His preoperative ASA-score was 3. The clinical and radiological (a,b,c) examination raised a strong suspicion of a loosening of the acetabular component. The stem showed no signs of loosening. The initiated surgical procedure confirmed the suspicion and an exchange of the acetabular component was performed (d,e,f). The intra-operative smear identified MRSE. Postoperatively the signs of infection persisted despite initiation of intravenous antibiotics according to the test criteria. Subsequently, we included the patient in our bacterial eradication program, including implant removal and implantation of a gentamicin-impregnated cement spacer (g). An instable proximal femoral fracture was set while removing the stem component. An osteosynthesis by a cerclage was applied limiting the alloplastic material in situ (g). After an uneventful period of 12 weeks without any signs of fracture, normal wound healing, no systemic inflammatory signs, and negative intra-operative smears, the re-implantation was performed (h) as a two stage hip replacement therapy. New signs of infections developed during the postoperative in-ward course. The operative revision including intra-operative smears identified the above mentioned MRSE. Thus a resection arthroplasty was performed (i,j). The further wound healing was uneventful. The patient was dismissed from the clinic 2 weeks after the operation. The patient is now mobile with crutches. The pain situation is tolerable.
Figure 2: Box plot comparing the body mass indices (BMI) between both patient groups.
Figure 3: The state of health of the patients, classified by the ASA-score. The upper bar chart contains the patients receiving a prosthetic re-implantation without infectious recurrence (group I). The lower diagram sums up the patients suffering from a failed infectious salvage (group II). The height of the bars represents the number of patients.
Figure 4: Percental level of resistance of the isolated pathogens of the patients of group I (upper chart). The lower chart accounts the percental level of resistance of the patient collective of group II. The classification of the level of resistance is specified in table 1.
Figure 5: Spectrum of pathogens of the patients of group I (upper chart) and group II (lower chart. Koagulase negative Staphylocci included Staphyloccuscapitis isolated in three patients and each of the following pathogens detected in one case: Staphylococcus warneri, Staphylococcus chromogenes, and Staphylococcus lugdunensis.