Purpose: The purpose of this study was to determine the usefulness of systematic bacteriological culture of drainage fluid after aseptic orthopaedic surgery in identifying infection early. There is much controversy over this point in the literature. In addition, the public health cost (approximately 30 euros per culture) must be considered in terms of effectivenes.

Material and methods: A prospective study was conducted in a single orthopaedic surgery department over a one-year period (1999) including all patients undergoing class I surgery (aseptic orthopaedic and traumatologic surgery). The population included 843 patients (52% men, 48% women, mean age 49 years, age range 15–98 years) who underwent 880 aseptic orthopaedic surgery procedures (osteosynthesis 60%, arthroplasty 30%, others 10%). One or several bacteriological cultures on early drainage fluid were performed (n=2434). The results of these cultures were analysed to determine their contribution to early detection of infection and rapid institution of adapted treatment (medical treatment with antibiotics or medical and surgical (revision) treatment).

Results: The bacteriological cultures were negative in 830 patients (98.5%) and positive in 13 (1.5%). A deep infection developed in 21 patients including 3 patients who had a positive drainage fluid culture and 18 who had a negative culture. In addition, ten patients had false positive cultures subsequent to extraneous contamination. The sensitivity, specificity and positive and negative predictive values were 14%, 98%, 23% and 98% respectively.

Discussion, conclusion: Drainage is a common procedure after orthopaedic surgery. The objective is to limit the risk of haematoma formation, but paradoxically with an increased risk of infection by retrograde contamination. The observed sensitivity and predictive values of drainage fluid cultures would suggest this is not a reliable method for detecting infection early, especially since the presence of a drain increases the risk of infection. In the final analysis, we do not recommend systematic culture of drainage fluid after aseptic orthopaedic surgery.

Purpose: The diagnosis of chronic bone and joint infections, particularly in patients with implants, can be a difficult task. Among the clinical and laboratory tests proposed for the diagnosis of infection, 99mTc HMPOA labelled leukocyte scintigraphy is one of the least invasive examinations available. We evaluated its efficacy in terms of reliability.

Material and methods: Ninety patients with suspected bone and joint infections were included in this study: 53% men and 47% women. Mean age was 56.6 years and 80% had osteosynthesis implants. Mean duration of clinical signs before scintigraphy was 6.5 months. The suspected site was the hip in 49%, the knee in 28% and another in 23%. Physical examination (local aspect, temperature) and laboratory tests (differential count, platelets, CRP, ESR) as well as standard radiographs were performed in addition to labelled scintigraphy. These patients were operated and bone samples were taken for bacteriology studies to confirm or infirm the presence of infection. In this series, 73% of the patients were found to have a real infection (73% staphylococcal, 17% multiple germs, 20% other).

Results: The following variables were included in the multivariate analysis: fever, standard radiographs, polynuclear neutrophil count, CRP, ESR, leukocyte-labelled scintigraphy. Sensitivity (Se), specificity (Sp), and odds ratio (OR) were determined. The multivariate analysis showed: fever (Se=0.48; Sp=0.59; OR=1.3); abnormal radiograph (Se=0.71; Sp=0.62; OR=4; p=0.02); polynuclear neutrophil count (OR=1; p=0.19); CRP (OR=1.02; p=0.06); ESR (OR=1.03; p=0.04); leukocyte-labelled scintigraphy (Se=0.71; Sp=0.82; OR=11.6; p< 0.001).

Discussion and conclusion: These findings demonstrate the efficacy of 99mTc HMPOA-labelled leukocyte scintigraphy in terms of reliability for the diagnosis of chronic bone infection compared with other clinical (fever), laboratory (ESR, CRP), and radiographic indicators.

Purpose: Patients hospitalized for osteomyelitis due to multi-resistant strains are often given prolonged parenteral antibiotics. Ambulatory parenteral antibiotic therapy is an alternative allowing outpatient care. The purpose of this study is to assess tolerance, cost and efficacy of this type of treatment.

Material and methods: Thirty-nine patients followed for osteomyelitis were included in this study. These patients were given antibiotics in a continuous infusion using a portable diffuser connected to an implanted chamber. Mean duration of treatment was four months, range 1.5–12 months. The follow-up team included the primary care physician, an infectious diseases specialist, and a nurse with special training in prolonged ambulatory antibiotic treatments. Results of weekly blood tests were transmitted to the referral hospital physician. Adverse effects and cost of prolonged ambulatory antibiotic therapy were recorded. Cost included costs for nurses, physical therapists, and physicians as well as drugs, supplies and laboratory tests. The cost of hospitalisation was determined on the basis of the standard cost for one day of hospitalisation in France.

Results: There were three cases of thrombophlebitis and one case of allergic reaction, both required re-hospitalisation. Cure was achieved in 93% of the patients. Mean follow-up since cure with discontinuation of the antibiotics was 18 months (14–22). Home care was possible in 100% of the patients and 23% of the patients were able to resume their occupational activity; 25% resumed their schooling. Self-administered schemes were possible in 23% of the patients. Compared with conventional hospitalisation, ambulatory parenteral antibiotic therapy enabled a cost savings of 1352 euros per patient.

Discussion: These results demonstrate that ambulatory antibiotic therapy is a very good alternative to classical hospitalisation enabling low morbidity, early resumption of social activities without loss of efficacy.