Infection after Internal fixation of fractures— challenges

Implants are used In Orthopaedic surgery for two purposes. They are used either in fractures as a fixator tool to guide the path of osteosynthesis or in severely traumatized or diseased joints, to replace it.

Infection after such surgeries is of grave concern and is to be taken seriously. Attempts have been made but fight to combat infection is yet to be won.There are several challenges pertaining to it.

There is no clear definition of surgical site infection.The CDC guidelines are used by many but it fails to include either the complexity of the fracture or the condition of the implant1 .Furthermore, osteomyelitis is separately stated2,3. The behavior of the infection and its impact on the implant is time dependent. Therefore a definition like the one given by Willinger and Roth in 1980s is very helpful. It classifies the infection as Early when it is less than 2 weeks, Delayed between 2- 10 weeks and Late more than 10 weeks4 . In case of Prosthetic joint infection such a time dependent definition already exists.

In early infection, biofilms are immature and bone shows no signs of osteolysis or osteomyelitis. Fracture is in soft callus stage.Normally, it goes to a hard callus state by 3 to 16 weeks5 . This is altered in a setting of late infection. Osteomyelitis and osteolysis compromises fate of the osteosynthesis. Sequestra and involucrum further walls off infection6 . Hence lies the importance of classifying according to time.

Aim in managing infection is eradication ; if it is not possible one should try to suppress it till the fracture unites. The mainstays towards this goal are:

1) Irrigation, debridement & retention of implant combined with antibiotic therapy

2) Debridement, implant removal or exchange supplemented with antibiotic therapy. However every case is unique and there is no standard procedure that can be applied in general.

Antibiotics play a pivotal role in a scenario of suppressing infection until the time implant is suitable for removal. However,no antibiotic can replace a manual debridement. When they are used for curative measures, duration is 6 weeks if implants are removed & 12 weeks if implants are retained7,8. For suppression, it is linked with the time fracture needs to stabilize & continued for 4-6 weeks after removal. Choice is best governed by culture and sensitivity results. Newer molecular methods are advocated nowadays to identify the organism’s.

Treating infection can cause a major burden to the socioeconomic status of both individual and the nation. Recent studies show that median costs per patient doubles when infected with reported success in 70-90% cases only 9,10,11. Hence, both preventive and treatment measures are to be improved. Such improvements may range from better defined & controlled peri-operative antibiotic prophylaxis to more rapid and specific diagnostics of even subclinical infection to increased availability of antimicrobial or functionalized medical devices.

Bibliography

1. Mangram AJ, Horan TC, Pearson ML, Silver LC, Jarvis WR. Guideline for Prevention of Surgical Site Infection . Centers for Disease Control and Prevention (CDC) Hospital Infection Control Practices Advisory Committee. Am J Infect Control 1999;96:3–4 27: 97-132

2. Lin S, Mauffrey C, Hammerberg EM, Stahel PF, Hak DJ. Surgical site infection after open reduction and internal fixation of tibial plateau fractures. Eur J OrthopSurgTraumatol 2014;24:797–803.

3. Bachoura A, Guitton TG, Smith RM, Vrahas MS, Zurakowski D, Ring D. Infirmity and injury complexity are risk factors for surgical-site infection after operative fracture care. ClinOrthopRelat Res 2011;469:2621–30.

4. Metsemakers WJ, Kuehl R, Moriarty TF, Richards RG, Verhofstad MHJ, Borens O, Kates S, Morgenstern M. Infection after fracture fixation: Current surgical and microbiological concepts.Injury. 2018 Mar;49(3):511 522. doi: 10.1016/ j.injury.2016.09.019. Epub 2016 Sep 11

5. T.P. Ruedi R.E. Buckley C.G. Moran K. Ito S.M. Perren R.G. Richards et al. AO Principles of Fracture Management – Volume 1 – Principles – Second expanded edition 2. ed: Thieme; 2007.

6. T.P. Ruedi, R.E. Buckley, C.G. Moran, K. Ito, S.M. Perren, R.G. Richards et al., AOPrinciples of Fracture Management _ Volume 2 _ Principles Second expanded, edition 2. ed: Thieme; 2007.

7. Trampuz A, Zimmerli W. Diagnosis and treatment of infections associated with fracture-fixation devices. Injury 2006;37(Suppl 2):S59–66.

8. Schmidt AH, Swiontkowski MF. Pathophysiology of infections after internal fixation of fractures. J Am AcadOrthopSurg 2000;8:285–91.

9. Thakore RV, Greenberg SE, Shi H, Foxx AM, Francois EL, Prablek MA, et al. Surgical site infection in orthopedic trauma: a case-control study evaluating risk factors and cost. J ClinOrthop Trauma 2015;6:220–6.

10. Berkes M, Obremskey WT, Scannell B, Ellington JK, Hymes RA, Bosse M, et al.Maintenance of hardware after early postoperative infection following fracture internalfixation. J Bone Joint Surg Am 2010;92:823–8.

11. Tschudin-Sutter S, Frei R, Dangel M, Jakob M, Balmelli C, Schaefer DJ, et al. Validation of a treatment algorithm for orthopedic implant-related infections with device-retention—results from a prospective observational cohort study. ClinMicrobiol Infect 2016.