SLR - November 2018 - Allie P. Cohen

The Value of Quantitative Histology in the Diagnosis of Fracture-Related Infection

Reference: M. Morgenstern, N.A. Athanasou, J.Y. Ferguson, W-J. Metsemakers, B.L. Atkins, M.A. McNally. The Value of Quantitative Histology in the Diagnosis of Fracture-Related Infection. The Bone and Joint Journal. 28 June 2018; 100-B966-72.

Scientific Literature Review

Reviewed By:
Allie P. Cohen, DPM
Residency Program: New York Presbyterian Queens, Flushing, NY

Podiatric Relevance: Along with clinical and radiographic findings, there is a role for histology when diagnosing an infected nonunion after a fracture. The presence of infection during fracture management affects the treatment protocol and overall prognosis of the patient. It is crucial to detect and recognized an infected nonunion. Fracture-related infections and nonunions are the most challenging complications in orthopaedic surgery, especially in trauma cases. Multiple factors are to be considered when evaluating a fracture-related infection, including initial bone and soft-tissue damage at the time of injury, anatomic location, hardware and fixation methods and patient-related health. This study aimed to interpret the role of quantitative histological analysis in the diagnosis of fracture-related infection. Histopathology studies are limited in regards to fracture-related infection, and there is no agreement on a cut-off value for neutrophil polymorphs infiltration as a criterion for diagnosis. A rather noninvasive histopathological bone biopsy can be sent for evaluation during any podiatric surgery when there is suspicion for an infected nonunion after fracture repair.

Methods: All skeletally mature patients receiving surgical treatment for nonunion of a long bone fracture were included at one institution. A total of 156 nonunions were eligible. The 156 nonunions were stratified into three diagnosis groups prior to surgery; confirmed infected nonunions, aseptic nonunions and possibly infected nonunions. During nonunion surgery, three to five clean, deep-tissue biopsies were sent for microanalysis and at least one sent for histology. All antibiotics were held at least two weeks prior to surgery. The histological inflammatory response was assessed by average neutrophil polymorph counts per high-power field and compared with the established diagnosis.

Results: The presence of more than five neutrophil polymorphs seen on histological exam only occurs when infection is present, while the complete absence of any neutrophil polymorphs is almost always indicative of an aseptic nonunion. These results show that histology can be used in a bimodal fashion as a diagnostic test.  

Conclusions: This article aims to help the surgeon diagnose infected nonunions with an increased degree of certainty and can perhaps help expedite the treatment plan. The results show that histopathological analysis has a role where there is a degree of suspicion for an infected nonunion when no definitive clinical or microbiological criteria exist. The podiatric surgeon has great use for histopathological analysis of possibly infected nonunions after fracture management. It can be used not only for traumatic orthopaedic injuries, but for cases where hardware and joint prosthesis are used for fracture management. The use of this quantitative histology of neutrophil polymorphs and clinical diagnosis can be used as protocol in diagnosing infected nonunions in fracture-related injuries. 

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