Efficacy of single dose versus multiple dose injectable antibiotics in hip joint surgery

Objective: To compare the efficacy of two prophylactic antibiotic regimens in preventing surgical site infection. Setting: Tertiary level hospital in India. Methods: We enrolled 104 consecutive patients undergoing elective implant surgery around the hip and randomized them into two groups. Group A (53) received a single dose of injectable cefazolin prior to skin incision, while group B (51) received additional 5 doses of injection cefazolin 12 hourly after the procedure. They were followed up for a minimum duration of 12 months and observed for the evidence of surgical site infection. Results: None of the patients from group A had surgical site infection, while 3 patients of group B (5.8%) developed infection. However, difference in infection rate was not significant statistically (p=0.114). Staphylococcus was isolated from 2 of the 3 infected surgical sites and Klebsiella from the third. Conclusion: Additional postoperative doses of cefazolin offer no advantage over its single pre-operative dose.