4. Practical recommendations
This in-depth review of the available literature establishes that
the diagnosis of post-arthroscopic septic arthritis is an emergency.
An early diagnosis is a prerequisite, not only to eradication
of the infection, but also to the achievement of good functional
outcomes. In some cases, however, the challenge is to rule out
post-arthroscopy infection, which may prove difficult. The clinical
manifestations, which consist chiefly in pain, are often ill-defined
and of unclear significance in postoperative patients. Thus, normal
pain due to the surgical procedure may be difficult to differentiate
from pain indicating a complication. Therefore, the possibility of
infection must always be borne in mind in patients with a troubled
postoperative course marked by unusually severe pain, delayed
range-of-motion recovery, or any other untoward event.
Many investigations are available for confirming or supporting a
diagnosis of septic arthritis. However, none can definitively rule the
diagnosis in or out. Furthermore, sophisticated tests often have long
times to results and may therefore delay the initiation of an effective
treatment strategy. Therefore, in practice, the wisest course of
action consists in performing a single investigation, namely, joint
aspiration with microbiological studies of the collected fluid. Presence
of a joint effusion is required but is the rule in this setting.
Aspiration of superficial joints (knee, ankle, shoulder, elbow, and
wrist) is easy to perform on an outpatient or inpatient basis. Aspiration
of the hip is also possible under these conditions, although
more likely to be successful when ultrasound guidance is used. Joint
aspiration is a rapid procedure that requires no special preparation
and is fairly inexpensive. It should be performed at the slightest
doubt and usually provides the diagnosis while also protecting the
physician in the event of litigation.
That joint aspiration can cause septic arthritis is a widely held
misconception. As with all invasive procedures, there is some risk,
but published estimates range from 1/10,000 to 1/100,000 aspirations.
Thus, any risk associated with joint aspiration is far lower
than the risk associated with allowing a joint infection to evolve.A positive joint aspiration, defined as purulent fluid or a positive
culture, confirms the diagnosis of infection, as false-positive results
due to sample contamination are exceedingly rare. Once the diagnosis
is confirmed and the causative organism identified, effective
treatment can be started immediately. The treatment strategy is
now well-standardised and will be described below. Effective and
early treatment provides the best chance of success and minimises
both the treatment duration and any residual abnormalities. The
expected outcome is eradication of the infection.
Although the patient may interpret the infection as indicative of
malpractice, the physician is unlikely to be found liable, except in
the tiny number of cases in which there is evidence of suboptimal
care. The liability falls on the healthcare institution. The surgeon is
usually subpoenaed to attend the expert review but can, in most
cases, prove that no mistakes were made and that the diagnosis
and treatment occurred as early as possible.
Negative joint aspirate cultures usually indicate that there is
no infection. Unfortunately, the diagnosis cannot be completely
ruled out. The patient should be monitored more closely than usual.
If the clinical manifestations are still present after a few days, a
second joint aspiration should be performed to allow further microbiological
studies. The treatment at this stage should be confined
to symptomatic measures. There is an absolute contra-indication
to probabilistic antibiotic therapy, as this course of action, far
from improving patient safety, can make the definite diagnosis
impossible to establish while failing to provide optimaltherapeutic
effectiveness.
If a definite diagnosis of infection is established, the patient may
consider malpractice litigation. However, the surgeon is unlikely
to be found liable, as the times to diagnosis and treatment were as
short as possible.
Failure to perform joint aspiration leaves the diagnosis in doubt
for several weeks. In the absence of infection,treatment delay is not
an issue and the surgeon may feel justified in not having performed
an unnecessary procedure. On the other hand, if a diagnosis of
infection is confirmed, the substantial delay in treatment initiation
will put the patient at risk for increased functional impairments.
The patient may be more likely to litigate and, more importantly,
the court will find the surgeon guilty of malpractice, consisting in
failure to investigate all possible diagnostic hypotheses.
When the diagnosis of septic arthritis is confirmed, treatment
must be started on an emergency basis. A prompt treatment
response increases the chances of a full recovery. Consequently,
a radical multipronged treatment strategy must be applied from
the outset. This strategy has three components.
Systemic antibiotics selected based on susceptibility test results
should be given routinely, as early as possible, and in sufficiently
high dosages. The intravenous route is used initially then the oral
route. Well-standardised protocols are now available, and the prescription
of antibiotics usually raises no special challenges.
Joint lavage should be performed routinely in post-arthroscopy
septic arthritis. Needle irrigation is inadequate, and surgical lavage
must be performed instead. Arthroscopic lavage is the preferred
technique, as it is less aggressive and potentially more effective for
complex joints such as the knee. However, open surgical lavage
remains an option. Large amounts of sterile saline should be used.
Adding antiseptic or antibiotic agents to the lavage fluid has not
been proven effective or, most importantly, safe.
Synovectomy is indicated in patients with marked synovial
hypertrophy and intra-synovial abscesses. The optimal extent of
the procedure is unclear, however, and is largely decided based on
subjective factors. Synovectomy should probably be as complete as
possible to maximally decrease the bacterial load. Excessive synovectomy
is lessharmfulthaninsufficient synovectomy, whichmay
delay the treatment response. Broad criteria should therefore be
used to select patients for synovectomy. Again, the arthroscopic approach is preferred, but open surgery is another option that may
allow more complete and, above all, faster removal of the synovial
membrane.
The best management of foreign material introduced into the
joints is less clear. Foreign material that is well-fixed within the
joint and continues to fulfil its function is unlikely to prevent eradication
of the infection and can be left in place. In contrast, if
the foreign material is not effective (e.g., ligament transplant that
has been destroyed or markedly weakened, ineffective sutures, or
mobile metallic material), removing it is reasonable. If appropriate,
it can be replaced by new material, depending on the situation and
potential difficulties