Summary

Graft contamination during ACL reconstruction is a common occurrence that must be considered. In the present study no correlation between graft contamination and postoperative septic arthritis.

Abstract

Introduction

Positive cultures ranging from 2 to 23% in the hamstring tendons graft among the studies. In only one out of 21 cases of positive graft culture and postoperative septic arthritis in the same patient was observed but the contaminating organism, was different from the organism isolated from the infection. Numerous studies, have demonstrated the effectiveness of the ‘vancomycin wrap’ in reducing infection rates compared to the use of preoperative prophylactic antibiotics alone, but the cost and the possible effect on the grafts properties remain controversial.

Purpose

Effects of harvesting, suture preparation and manipulation on hamstrings graft contamination, has not been well-explained in anterior cruciate ligament reconstruction (ACLR). This study aimed to evaluate the incidence of hamstring autograft contamination at different time points of graft harvesting and preparation and investigate differences in contamination between the phases of ACL reconstruction. Also, the association between intraoperative contamination and the development of clinical infection was evaluated.

Methods

Between 10/2021 to 7/20022, from 33 hamstring tendon (HT) graft specimen culture were obtained (79% male, 21% female). All patients received standard antibiotic prophylaxis before and after surgery. Number one sample was obtained immediately after harvesting and number two after preparation and stabilization of the graft in the end of the procedure. The graft size was measured and was kept moist in the operating room environment after the initiation of preparation. The time was recorded simultaneously. Any bacterial growth and the number of colonies forming units were reported. Culture results were classified as positive or negative.

Results

The average time between the harvesting to the final fixation of the graft was 36.36 minutes (30-45 min). Graft size was between 7-9mm. The specimens had a positive culture sample at a rate of 12/33 (36,36%). In Sample 1 was detected a higher contamination rate with positivity of 11/33. Sample 2 was positive at a rate if 8/33. The contamination rate was higher pre-suturing 11/33, (33,33%) than after manipulation 8/33 (24,24%). Of the 9 positive cultures of sample 1 the isolated bacterial species were CNS at 10/11 (91%). On sample 2 CNS at 7/8 (87,5%). One culture was positive for both samples for acinetobacter baumannii, klebsiella, pneumoniae (9%). No statistically significant differences were found between the graft size and the time of preparation/manipulation. No case of postoperative septic arthritis was observed.

Conclusion

Graft contamination during ACL reconstruction is a common occurrence that must be considered. In the present study no correlation between graft contamination and postoperative septic arthritis. Nonetheless, standard prophylaxis (sterile operating room environment, appropriate patient preparation, including pre-washing with chlorhexidine, ventilation, antibiotics) remain key to preventing sepsis.