1. M.Rao St Richard’s Hospital, Chichester West Sussex.
Does decolonisation of MRSA decrease the risk Of Surgical Site Infection in THA & TKA ?
M.Rao
St Richard’s Hospital, Chichester
West Sussex.

2. Introduction
Risk of developing SSI in trauma patients colonised with MRSA is 2.5 times greater than that of non-colonised patients.
Shukla et al; J Bone Joint Surg Br -2009
Few studies to assess for incidence of SSI in MRSA carriers in elective orthopaedic surgery following decolonisation Hacek et al- Clin Orthop Relat Res-2008.
Rao et al-Clin Orthop Rel Research-2008.
Decolonisation not confirmed prior to surgical intervention

3. Objectives
Study to determine the risk of SSI in elective primary hip and knee replacements who had successful preoperative decolonisation and confirmed eradication of MRSA carrier status.

4. Patients and Methods
Retrospective analysis of consecutive elective THA’S & TKA’s done between January 2008 and October 2012.
List of patients generated using OPCS codes (Audit Dept.) for Primary THA & Primary TKR (cemented/uncemented/Hybrid).
Microbiology data (sema helix).
Infection Control data from Infection control Nurse specialists. (HES data)

5. MRSA decolonisation Protocol
Standardised decolonisation protocol for MRSA+ve patients
Mupirocin (2%) nasal ointment 3 times a day for 5 days.
Daily bathing with chlorhexidine 4% / Surgical scrub for 5 days.
Chlorhexidine 4% surgical shampoo for hair on days 1 & 3.
Repeat full MRSA screens (3 sets of – ve swabs before surgery)
Negative swabs ranged from 3-5 prior to surgery
All patients in the study group had negative swabs (most within 3 weeks prior to surgery)

6. Detailed medical records of MRSA colonised patients assessed.
Methods
Detailed medical records of MRSA colonised patients assessed.
Site of colonisation.
Risk factors for colonisation.
Co-morbidities.
Eradication of colonisation status prior to surgery.
Prophylactic antibiotics used in the peri-operative period.

7. (WHO guidelines for safe surgery-2009)
Methods
Development of SSI in the subsequent year after surgery
MRSA negative patients cohort served as the control group.
Only patients identified to have “ deep SSI” as defined by WHO classification were included in the study.
(WHO guidelines for safe surgery-2009)

8. Results Over all Colonisation rate -1.3% Total No of Patients – 6613
MRSA positive - 83
Mean Age (MRSA positive) - 76 yrs
M:F ratio 1:1.2
Sites of Colonisation
Nasal-31
Multiple sites – 52 Patients
Over all Colonisation rate -1.3%

9. Additional Risk Factors & Medical Co-Morbidities
3 patients were in the “high risk” category for MRSA colonisation.
Previously colonised with MRSA - History of leg cellulitis and ulcers.
Medical Co-morbidities
Diabetes-15 patients
Rheumatoid Arthritis(on steroids/methotrexate)- 7 patients.
Stage 3 CKD-1 patient – Immunocompamised.

10. Perioperative Antibiotic prophylaxis
60% patients received Teicoplanin for antibiotic prophylaxis.

11. Results January 2008- October 2012 3347 THR’s 3266 TKR’s 6613 screened
79 positive
4 excluded
THR’s
TKR’s
6613 screened
83 MRSA + ve
5 deep SSI
6530 MRSA - ve

12. Results – MRSA Positive Patients
Age
Gender
Procedure
Site of colonisation
Prophylactic Antibiotic
Infection type 79 F
TKR
Multiple
Flucl/Gent
MRSA 80 M
Teicoplanin
MSSA 78
THR 84
5 of 79 patients had deep SSI
4 deep MRSA and 1 deep MSSA.
3 out of 5 patients who developed SSI had Teicoplanin.
Overall infection rate of 6.32%

13. Analysis of Total Hip Replacements
Previous MRSA colonisation
Total THRs
Deep sepsis THR
Infection (%)
Chi square value
P- value
Positive 38 2
5.26%
4.858
.0275
Negative
3307 39
1.17% .

14. Analysis of Total Knee Replacements
Previous MRSA colonisation
Total TKR
Deep sepsis TKR
Infection (%)
Chi square value
P- value
Positive 41 3
7.31%
9.904
.0016
Negative
3223 42
1.3%

15. Literature In Elective Orthopaedic Surgery Rao N et al.- CORR -2008
Kim D et al.- JBJS (Am.)- 2010
‘’ Identified implementation of universal screening & selective decolonisation of MRSA carriers leads to a reduction in post op SSI ’’.
(These studies did not confirm eradication prior to surgery)
Murphy et al.(Glasgow Royal Infirmary)-JBJS(Br.)-2011
Identified a 6.7% risk of SSI in elective orthopaedic surgery following confirmed decolonisation/eradication
[ 1st study of this nature in literature]
Cefuroxime was used as perioperative antibiotic prophylaxis
(Queried if use of vancomycin/teicoplanin would make a difference)

16. Do we completely eradicate MRSA using current decolonisation protocols ????
Probably Not !
Valde’s C et al; Incidence of bacteraemia associated with tracheal intubation.- Anaesthesia-2008
Possible explanation- High rates of SSI in these patients is caused by bacteraemia ⟹ trauma to mucosa of URT during intubation ⟹ seeding of prosthetic implants ⟹ these areas not decolonised without use of oral chlorhexidine sprays.

17. Conclusions
There is a significantly increased risk of SSI in MRSA colonised patients (6.32%) undergoing elective hip and knee replacements, despite confirmed eradication/decolonisation.
Also, should infection develop, MRSA is the more often the causative organism.
Patients should be made aware of this higher risk of infection and the serious consequences of developing MRSA SSI.

18. Conclusion Best way to treat MRSA is to avoid it!
there's no app for MRSA eradication
Thank You