Bioburden Study

Principal Investigator: ThomasHiggins
Keywords: wound closure , Deep wound infection Department: Orthopedic Surgery
IRB Number: 00052654 Co Investigator:
Specialty: Orthopaedic Surgery
Sub Specialties: Orthopaedic Trauma

Contact Information


Brief Summary

The primary objective of this study is to characterize the contemporary extremity wound “bioburden” at the time of definitive wound coverage/closure of severe extremity military and civilian wounds. We will analyze routine tissue samples collected as part of standard of care employing both standard tissue culture microbiology and modern polymerase chain reaction (PCR) technologies. 

Secondary objectives of the study are to determine: (a) the correlation of the identified wound pathogens at the time of wound closure/coverage with subsequent deep wound infections; (b) the correlation of the PCR results with those obtained from standard hospital microbiology; and (c) the efficacy, if any, of antibiotics used in the care of the wound.

Detailed Description

Infection remains the most common and significant complication following high energy fractures, with rates ranging from 25 – 40%. Up to 15% of recent combat casualties develop osteomyelitis.The large traumatic wounds are inoculated with environmental bacteria at the time of injury and are exposed to host and hospital flora colonization during the initial treatment course. In contrast to significant advances made in related extremity trauma care disciplines, the strategies that address the prevention of deep infection following severe open fracture wounds have remained constant for the past 20 years. Few surgeons sample the wound bioburden at the time of closure, typically related to the unreliable results from the routine microbiology at predicting subsequent failure due to infection. Evidence supports the initial administration of systemic antibiotics as effective in reducing the infection rate in open fracture care. Many patients with severe extremity wounds are multiple trauma patients, faced with recovery from head, chest and abdominal injuries associated with the extremity injury. These patients are at risk for the development of nosocomial infections and for infection with resistant pathogens. Prolonged or repeated systemic antibiotic exposure is avoided, if possible, in this cohort. The long term impact of systemic antibiotic therapy on severe extremity wounds is currently unknown and may be counter-productive. When antibiotics are administered, a directed therapy approach is preferred. Tissues in the zone of injury are often hypoperfused and the antibiotic concentration in the critical injured tissues is less than the desired therapeutic level. The wound bacteria and fungi can attach to soft tissues, bone or metal implants and initiate biofilm production. Biofilm colonies are increasingly recognized as the likely source of chronic and implant related infections. Traditional antibiotics are unable to penetrate the biofilm meaning multi-component therapies that prevent biofilm development are needed. Over the next decade, the treatment of the severe wound is expected to dramatically change. Local wound anti-microbial therapies employing bio-degradable micro or nanospheres, ceramics or chitosan sponges may likely replace systemic therapy. These local antibiotic treatments might be potentiated by combining them with biofilm disbursing agents (bismuth thiols).

Inclusion Criteria

1.All open Grade III tibia fractures (plateau, shaft and pilon) requiring a second procedure following fixation, or traumatic transtibial amputations requiring delayed primary closure, skin grafting and/ or flap coverage.
2.Ages 18 – 64 years inclusive
3.Patients may have risk factors for infection including diabetes, immunosuppression from steroids or other medications, HIV, or other infections.
4.Patients may have a traumatic brain injury.
5.Patients may have other fractures including spine, upper extremity fractures, contralateral lower extremity injuries, ipsilateral pelvis, hip, femur or foot injuries.
6.Patients may be treated initially at an outside institution prior to transfer to the study institution, as long as the definitive fixation was not performed prior to entrance into the study.
7.Patients with bilateral injuries that meet inclusion criteria may be included, but only the limb rated as “more severe” by the treating surgeon will be enrolled in the study.
8.Patients may have co-existing non-tibial infection, with or without antibiotic treatment.
9.Patients may have an existing infection of the surgical wound under treatment at the time of wound closure.
10.Patients may be definitively fixed using any method (nail, plate, ex fix)
11.Patients may have a fasciotomy

Exclusion Criteria

1.Patient speaks neither English nor Spanish
2.Patient is a prisoner
3.Patient has been diagnosed with a severe psychiatric condition
4.Patient is intellectually challenged without adequate family support
5.Patient lives outside the hospital’s catchment area
6. Patients with planned follow-up at another medical center