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JUEVES / THURSDAY
184
THE DIAGNOSIS AND
MANAGEMENT OF
PERI-PROSTHETIC
INFECTIONS
P. McLardy-Smith,
B. Atkins, H. Pandit, T. Berendt,
N. Athanasou & the Oxford
Hip and Knee Group
Nuffi eld Orthopaedic Centre, Oxford, UK
Total hip replacement is probably the most
successful operation ever devised and other
joints, particularly the knee are now being successfully
replaced. However peri-prosthetic
infection remains a potentially catastrophic
complication. Infection rates are reported at
between 1- 2% and the risk of a peri-prosthetic
infection runs over the entire life time of the
joint. Peri-prosthetic infections can usefully
categorised as early acute or chronic and late
acute or chronic. The diagnosis of chronic
infections, particularly late ones, may be diffi
cult to achieve pre-operatively. Imaging techniques
and serological testing can be useful
but are not as yet reliable or specifi c. Aspiration
or closed biopsy are similarly unreliable.
Any joint revised for any reason may have an
underlying infection. In a prospective study
of 334 consecutive hip and knee revisions
we sent multiple samples from each case for
bacteriological and histological analysis. We
used the histological appearance as the criterion
for defi ning infection. By this defi nition
15% of infected cases were culture negative
and one positive culture specimen has no
predictive value for under lying infection. Two
or more positive cultures out of 5 or 6 samples
as a useful predictive value.
In acute infections, if the components are
soundly fi xed, salvage should be attempted
with adequate debridement sampling and
lavage of the joint. Arthroscopic washout in
Staphylococcal knee infections has a very
poor outcome. We would then recommend
long term antibiotic therapy. Salvage maybe
possible in chronic infections, but usually the
components are loose within the bone and a
full revision will be required. Frozen section
histological analysis of the tissue at the time
of surgery can differentiate septic from aseptic
loosening and maybe relied upon to choose
between a one or a two stage revision.
INFECTED TOTAL HIP
ARTHROPLASTY. ONE
STAGE REVISION
B. M. Wroblewski, P. D. Siney,
P. A. Fleming
The John Charnley Research Institute,
Wrightington Hospital, Hall Lane,
Appley Bridge Near Wigan U.K.
One of the most serious complications of
THA is deep infection. Charnley realised
the problem. This led to the development
of clean air enclosure, total body exhaust
suits and the introduction of the instrument
tray system. Subsequently antibiotics were
used both systematically and also as an addition
to the acrylic cement. Occasional deep
infection requires further intervention, either
by removing the implant, or performing one
or two stage revision. It has been the senior
author’s practice to undertake one-stage
revision provided the bone stock was of suffi
ciently good quality to ensure reasonable
quality of component fi xation. The technique
is based on the accepted principle of infection
management: Removal of all foreign body
material and infected tissues, application of local
antiseptics/antibiotics, closure of cavities,
ensuring stability, drainage, rest, continuation
of antibiotics.
Between January 1974 and December 2001,
185 one-stage revisions were carried out by
the senior author: 162 had a minimum fol-