Antibiotics are an integral part of infection prophylaxis in orthopaedic surgery, and tourniquets are widely used during many of those same surgeries. The timing of antibiotic administration in relation to tourniquet use has long been debated. Hanberg et al. explore this “balancing act” in the November 4, 2020 issue of The Journal in a carefully performed animal study.
The researchers anesthetized 24 female pigs and surgically exposed both of their hind calcanei. They then placed microdialysis catheters through drill holes in each calcaneus and also into the subcutaneous adipose tissue in the hind feet. Tourniquets were applied to one hind leg on each animal, and each pig was then randomized into 1 of 3 groups, based on when the animal received 1.5 gm of cefuroxime intravenously:
- Group A –15 minutes prior to tourniquet inflation
- Group B – 45 minutes prior to tourniquet inflation
- Group C – At the time of tourniquet release
Hanberg et al. inflated the tourniquets for 90 minutes in all 3 groups, and then they measured the concentrations of cefuroxime and ischemic markers at regular intervals between the time of tourniquet inflation and up to 480 minutes afterward.
The authors found that in both Groups A and B, cefuroxime concentrations were maintained above the minimum inhibitory concentration (MIC) for Staphylococcus aureus in cancellous bone and adipose tissue throughout the 90 minutes of tourniquet inflation. In addition, injecting cefuroxime at the time of tourniquet deflation (Group C) kept the tissue-antibiotic levels above the MIC on the tourniquet side for 3.5 hours after tourniquet release.
There were no differences in the time above MIC in bone or adipose tissue between the 3 groups, but the researchers noted a trend toward shorter time above MIC in bone in Group A vs. Group C (p=0.08). There was also a tendency toward higher time above MIC in bone on the tourniquet side compared to no-tourniquet side in Group B (p=0.08) and Group C (p=0.06). The researchers also found that, in all the animals, tissue ischemia persisted for 2.5 hours after tourniquet deflation in bone, while the adipose tissue recovered immediately.
This animal study provides useful data and prompts us to ponder ideas for further investigation regarding the interplay between tourniquets and antibiotic perfusion. For example, I think the prolonged ischemia in cancellous bone is a topic that warrants further investigation, and I am also curious whether adding antibiotics at the time of tourniquet release might help combat the potentially negative effects of that ischemia.
Matthew R. Schmitz, MD
JBJS Deputy Editor for Social Media
Previously this month, Chad A. Krueger, MD, JBJS Deputy Editor for Social Media, selected what he deemed to be the most clinically compelling findings from among the more than 150 studies cited in the January 17, 2018 Specialty Update on Adult Reconstructive Knee Surgery. In this OrthoBuzz post, Gwo-Chin Lee, MD, author of the Specialty Update on Adult Reconstructive Knee Surgery, selects his “top five.”
Nonoperative Knee OA Treatment
—Atukorala et al. found a significant dose-response relationship between all KOOS subscales and percentage of weight change across all weight-change categories. Participants required ≥7.7% of weight loss to achieve a minimal clinically important improvement in function.1
—A prospective cohort study showed that patients undergoing arthroscopic procedures for degenerative meniscal tears did not have clinically meaningful differences in outcomes compared with patients with traumatic meniscal tears.2
Postoperative Pain Management
—Authors of a Cochrane Systematic Review ascertained that liposomal bupivacaine at the surgical site appears to reduce postoperative pain compared with placebo. However, because of the low quality and volume of evidence, it is not possible to determine its effect compared with conventional agents.3
Avoiding Post-TKA Complications
—In a randomized trial, the use of a tourniquet resulted in upregulation of peptidase activity within the vastus medialis but did not result in an increase in muscular degradation products. The authors concluded that the relationship between tourniquet-induced ischemia and muscle atrophy is complex and poorly understood.4
—The authors of a registry study found no evidence that fondaparinux, enoxaparin, or warfarin are superior to aspirin in the prevention of PE, DVT, or VTE—or that aspirin is safer than these alternatives. However, enoxaparin is as safe as aspirin with respect to bleeding, and fondaparinux is as safe as aspirin with respect to risk of wound complications.5
- Atukorala I, Makovey J, Lawler L, Messier SP, Bennell K, Hunter DJ. Is there a dose-response relationship between weight loss and symptom improvement in persons with knee osteoarthritis? Arthritis Care Res (Hoboken). 2016 Aug;68 (8):1106-14.
- Thorlund JB, Englund M, Christensen R, Nissen N, Pihl K, Jørgensen U, Schjerning J, Lohmander LS. Patient reported outcomes in patients undergoing arthroscopic partial meniscectomy for traumatic or degenerative meniscal tears: comparative prospective cohort study. BMJ. 2017 Feb 2;356:j356.
- Hamilton TW, Athanassoglou V, Mellon S, Strickland LH, Trivella M, Murray D, Pandit HG. Liposomal bupivacaine infiltration at the surgical site for the management of postoperative pain. Cochrane Database Syst Rev. 2017 Feb 1;2:CD011419.
- Jawhar A, Hermanns S, Ponelies N, Obertacke U, Roehl H. Tourniquet-induced ischaemia during total knee arthroplasty results in higher proteolytic activities within vastus medialis cells: a randomized clinical trial. Knee Surg Sports Traumatol Arthrosc. 2016 Oct;24(10):3313-21. Epub 2015 Nov 14.
- Cafri G, Paxton EW, Chen Y, Cheetham CT, Gould MK, Sluggett J, Bini SA, Khatod M. Comparative effectiveness and safety of drug prophylaxis for prevention of venous thromboembolism after total knee arthroplasty. J Arthroplasty. 2017 Nov;32(11):3524-28.e1. Epub 2017 May 31.