Humidity a potential risk factor for prosthetic joint infection in a tropical Australian hospital.

BACKGROUND: Many pathogens of importance, including the staphylococcal species of concern in orthopaedics, demonstrate seasonal variations influenced by environmental factors. The aim of this study was to investigate the role of humidity as a risk factor for deep prosthetic joint infection following total knee arthroplasty (TKA) in a tropical Australian hospital. METHODS: A retrospective cohort study of all TKAs performed over a 13-year period was conducted at the author's institution. Univariate analysis was used to individually assess for a range of risk factors including humidity >60% and apparent temperature >30°C (86°F). Odds ratios (ORs) were reported. P-values <0.25 were considered as potentially important risk factors and P-values <0.05 were considered statistically significant. RESULTS: A total of 1058 primary TKAs were performed with a deep prosthetic joint infection incidence of 2.7%. Four potential risk factors were identified with P-values <0.25: (i) humidity >60% (OR 1.4; 95% confidence interval (CI) 0.68-3.04; P = 0.221); (ii) apparent temperature >30°C (86°F) (OR 2.4; 95% CI 0.56-10.1; P = 0.174); (iii) male gender (OR 2.2; 95% CI 1.02-4.81; P = 0.057); and (iv) American Society of Anesthesiologists score of III or IV (OR 2.1; 95% CI 1.00-4.49; P = 0.064). CONCLUSION: Humidity and apparent temperature may be potentially important risk factors for infection following TKA.

An Unusual Cause of Dysphagia: A Large Expectorated Arteriovenous Malformation.

BACKGROUND: Vascular malformations are generally detected in childhood or adolescence with first presentations in adulthood being rare. CASE REPORT: We report the case of a 52-year-old female with threatened compromise of her airway after expectorating a massive arteriovenous malformation anchored at the supraglottis. The only preceding symptom was dysphagia. The lesion was resected, the patient had a quick recovery, and she has shown no evidence of recurrence. CONCLUSION: Although uncommon, vascular malformations of the supraglottis or hypopharynx should be considered in the differential diagnosis of a patient presenting with dysphagia because of the potential to cause disastrous airway compromise. Although a lesion presenting acutely mandates a definitive airway plan, when clinically possible, computed tomography scan and indirect laryngoscopy can provide useful information for the airway and operative teams.