Introduction: Deep infection continues to be the first most important early complication in knee arthroplasty. It is usual to apply standard prophylaxis to all patients, but it is not usual to use special measures in those of them who present a higher risk. Moreover, sometimes these patients are even not identified.

Purpose: To analyse statistically significant risk factors for deep infection in patients with a knee arthroplasty.

Patients and Methods:

Design: Case-control study.

Observational and retrospective comparison of incidence or prevalence of all risk factors described in the literature. These factors have been classified according to the period of risk in: epidemiologic; pre, intra and postoperative; and distant infections.

Case series: 32 consecutive patients with a deeply infected knee arthroplasty operated in the same Department of a University General Hospital.

Control series: 100 randomly selected patients, operated in the same hospital and period of time, with no deep infection in their knee arthroplasty along follow-up.

Pearson was used for comparison of qualitative variables and ANOVA for quantitative ones.

Results: The following risk factors were significantly more frequent (p< 0.05) in the patients with an infected knee arthroplasty:

Preoperative conditions: previous surgery in the same knee (25% vs 9%), chronic therapy with glucocorticoids (19% vs 4%), immunosuppressive treatments (16% vs 3%), and non-rheumatoid inflammatory arthritis (13% vs 0%). Patients in this case-control did not present a significant difference in the prevalence of rheumatoid arthritis, diabetes, obesity (BMI> 30), chronic liver diseases, or alcohol addiction.

Conclusion: To identify significative risk factors for deep infection in knee arthroplasty is important:

to control and minimize these risk factors when present

Introduction and Objectives: The medical literature describes asymptomatic urinary tract infections (UTI) in up to 30% of postmenopausal women. Our aim was to analyze the prevalence of asymptomatic UTI in patients waiting to undergo programmed hip/knee arthroplasty and also the risk of dissemination of the infection through the blood stream.

Materials and Methods: We included 200 patients that had undergone hip/knee arthroplasties in our study (15.1.07–22.10.07). 69.97+/−10.28 years of age, 130 women/70 men. Urine and sediment analysis on entry (12 hours before surgery). Abnormal values: density< 1.006/> 1.030; pH< 4.6/> 7.0; leucocytes and/or positive nitrites; sediment with bacteriuria, piuria and/or > 5 leucocytes/field. If the urine or sediment analysis gave abnormal values: Preoperative quantitative urine culture. If < 10.000 CFUs/ml, no UTI; > 10.000 but < 100.000 urine culture is repeated; > 100.000 CFUs, diagnosis of UTI, specific antibiotics orally for 7 days during the postoperative period. None of the patients underwent urethra catheterization. All received cefazoline 1g i.v/8 hours for 48 hours postoperatively.

Results: Loss to follow-up: 0 patients. If the urine or sediment analysis gave abnormal values: 82/200 patients of 72.59+/−7.32 years of age, 72 women/10 men. In 11/82 patients: no valid uroculture. In 8/82 patients (8/200, 4% of the total series): Pathological urine culture, 4 E. coli, 1 P. aeruginosa, 1 P. putida, 1 K. oxytoca, 1 K. pneumoniae. Treatment: quinolones/amoxicillin-clavulanic acid (not carried out in 3 cases). Up to the now there are no signs of infection in the arthroplasties.

Discussion and Conclusions:

Patients undergoing programmed hip/knee arthroplasties frequently have abnormal preoperative urine analysis.

Introduction: There are descriptions in the medical literature of asymptomatic bacteriurias in 30% of post-menopausal women.

Purpose: To analyze the prevalence of asymptomatic bacteriuria and the risk of blood-route dissemination in patients undergoing elective hip arthroplasty.

Patients and Methods: All asymptomatic patients undergoing surgical hip arthroplasty between January 15, 2007 and March 30, 2007 were included. There was a total of 45 patients of 65.9 +/−12.9 (range: 33–85) years of age, out of which 23 (51.1%) were male. A urine test was administered on admission (12 hours before surgery). Normal analysis: density< 1.006/> 1.030; pH< 4.6/> 7.0; leucocytes and/or positive nitrites; sediment with bacteriuria, piouria and/or > 5 leucocytes/field. If the urine analysis was abnormal, a preoperative quantitative uroculture was carried out. If < 10000 CFUs/ml, no UTI (urinary tract infection); if > 10000 but < 100000, a new urine culture was performed; if > 100000 CFUs, diagnosis of UTI, specific oral antibiotics were administered for 7 days postoperatively. None of the patients underwent urethra catheterization. All received cefazoline 1g i.v/8 hours for 48 hours postoperatively.

Results: Loss to follow-up: 0 patients. Normal analysis: 12/45(26.7%) patients of 73.8+/−8.5 (55–85) years of age, 12 females (100.0%). In 1 of these 12 patients (8.3%) (1/45 or 2.2% of the total series) the urine culture was positive for Pseudomona aeruginosa. Up to the current time none of these 45 patients has developed signs of infection in their arthroplasty.

Conclusions:

(1) Women undergoing elective hip arthroplasty frequently have abnormal preoperative urine analysis.