Allograft bone chips used in complex bone reconstruction procedures are associated with an increased infection risk. The perioperative use of systemic cefazolin is standard to prevent infection, but is less effective in the presence of avascular bone grafts. Bone chips have been described as a carrier for local delivery of antibiotics, but impregnation with cefazolin in a prophylactic setting has not been described. We aimed to obtain a prolonged cefazolin release from bone chips to maximize the prophylactic effect. Three types of bone chips were evaluated: fresh frozen, decellularized frozen and decellularized lyophilized. Bone chips were incubated with 20 mg/ml cefazolin or treated with liquid hydrogel containing either 1 mg/ml fibrin or 1 mg/ml collagen and 20 mg/ml cefazolin. The cefazolin hydrogel was distributed in the porous structure by short vacuum treatment. Bone chips with cefazolin but without hydrogel were incubated for 20 min- 4h under atmospheric pressure or under vacuum. Cefazolin elution of bone chips was carried out in fetal bovine serum and analyzed by Ultra Performance Liquid Chromatography – Diode Array Detection.Aim
Method
Smoking is negatively implicated in healing and may increase the risk of surgical complications in orthopaedic patients. Carbon monoxide (CO) breath testing provides a rapid way of measuring recent smoking activity, but so far, to our knowledge, this has not been studied in elective orthopaedic patients. We studied whether CO-testing can be performed preoperatively in elective orthopaedic patients and whether testing accurately correlates with self-reported smoking status? CO breath testing was performed on and a brief smoking history was obtained from 154 elective orthopaedic patients on the day of surgery. All patients admitted over 6 weeks for elective orthopaedic intervention were enrolled. 16.2% patients admitted to smoking. The mean CO levels were 15.2 ppm for self-reported smokers and 3.1 ppm for self-reporting non-smokers. One self-reporting non-smoker admitted to smoking after testing. 5 non-smoking patients had a CO breath of >=7, 1 had a CO level of >= 10 ppm. Using a cutoff of 7 ppm gave a sensitivity of 65.4% and a specificity of 96.1%, whilst a cutoff of 10 ppm gave a sensitivity of 57.6% and specificity of 99.2%. Whilst most patients are honest about smoking, CO testing can identify non-disclosing smokers undergoing elective orthopaedic procedures. Due to the high specificity, speed and cost-effectiveness, CO breath testing could be performed routinely to identify patients at risk from smoking-related complications in pre-assessment clinics. Smoking cessation services may reduce the risk of harm. CO testing on admission may demonstrate the efficacy of smoking cessation services.
