Serum amyloid A and fibrinogen as markers for early detection of surgical site infection associated with internal fixation in the horse.

Authors: Thurston Catherine C, Stefanovski Darko, MacKinnon Melissa C, Chapman Hannah-Sophie, Richardson Dean W, Levine David G

Journal: Frontiers in veterinary science

DOI: 10.3389/fvets.2022.960865 PubMed: 36299628Log in to save

Summary

# Editorial Summary Surgical site infection (SSI) remains a significant complication following equine internal fixation procedures, yet early detection remains challenging when clinical signs are subtle. Thurston and colleagues investigated whether two acute phase proteins—serum amyloid A (SAA) and fibrinogen—could reliably identify horses developing SSI by measuring these markers preoperatively and serially through day 14 post-surgery in horses undergoing fracture fixation, arthrodesis, or correction of limb deformities. SAA proved substantially more diagnostically useful than fibrinogen, with an area under the ROC curve of 0.8 (excellent discrimination) compared to fibrinogen's 0.7 (acceptable discrimination), and SAA's predictive value strengthened as the postoperative period progressed, suggesting that *persistent* elevation rather than immediate postoperative increases carries clinical significance. The practical implication is straightforward: serial SAA monitoring in the postoperative period offers veterinary surgeons an objective tool to heighten suspicion for developing SSI before overt clinical deterioration, potentially enabling earlier intervention with antimicrobial therapy, drainage, or surgical exploration. Whilst fibrinogen retains value as a supportive marker, SAA should be prioritised in postoperative monitoring protocols for equine internal fixation cases, particularly when clinical assessment remains equivocal.

Read the full abstract on PubMed

Practical Takeaways

•Use serial SAA measurements (days 1-14 post-op) as an early warning system for surgical site infections in horses with internal fixation—persistent elevations warrant investigation before clinical signs appear
•SAA outperforms fibrinogen as a predictor, so prioritize SAA monitoring if you can only run one test
•Enables earlier recognition and treatment of SSI, potentially improving outcomes and reducing complications in fracture repair cases

Key Findings

•Serum amyloid A (SAA) is an excellent diagnostic marker for surgical site infection with area under ROC curve of 0.8, superior to fibrinogen (0.7)
•Persistent SAA elevations postoperatively are associated with development of SSI
•SAA diagnostic utility increases with time postoperatively for detecting SSI
•Serial monitoring of SAA can help predict SSI development in horses undergoing internal fixation

Conditions Studied

surgical site infection (ssi)fracture with internal fixationarthrodesisosteotomy with internal fixationlimb deformity

Related References

Serum amyloid A and plasma fibrinogen concentrations in horses following emergency exploratory celiotomy.

De Cozar M, Sherlock C, Knowles E, Mair T(2020)Equine veterinary journal

Use of serum amyloid A and other acute phase reactants to monitor the inflammatory response after castration in horses: a field study.

Jacobsen S, Jensen J C, Frei S, Jensen A L, Thoefner M B(2005)Equine veterinary journal

Systemic serum amyloid A in early (<24 h) diagnosis of acute synovial structure involvement in horses with penetrating limb injuries.

Müller A C, Büttner K, Röcken M(2021)Veterinary journal (London, England : 1997)

Course of serum amyloid A (SAA) plasma concentrations in horses undergoing surgery for injuries penetrating synovial structures, an observational clinical study.

Haltmayer Eva, Schwendenwein Ilse, Licka Theresia F(2017)BMC veterinary research

Serum amyloid A concentration in postoperative colic horses and its association with postoperative complications.

Aitken Maia R, Stefanovski Darko, Southwood Louise L(2019)Veterinary surgery : VS