Diagnosis
of sports injuries
The first question that a surgeon must ask himself or herself is whether
the extent of the injury is in keeping with the description of the mechanism
of injury. In other words, was this normal tissue that was injured because of an
abnormal load applied to it, either a single high load or many cycles of low
load? In this situation successful resolution of the injury and avoidance of the
abnormal load should prevent recurrence. However, if a relatively normal load
resulted in injury then the tissue was probably abnormal and the underlying
abnormality is the main concern.
All
of these points serve to emphasise the importance of good history taking and
careful clinical examination. They still form the cornerstone of diagnosis in
all branches of medicine but especially with injuries to the soft tissues.
Arthroscopy versus imaging
The principle of using the arthroscope and specialised imaging
techniques to diagnose pathology is to be decried. The arthroscope should be
used to confirm and treat pathology identified by the surgeon from the
history and clinical examination. If the signs and symptoms elicited are not
sufficient to establish a diagnosis, then an arthroscopy will not advance
matters. For example, arthroscopic confirmation of a torn anterior cruciate
ligament is a wasted procedure: the knee is either clinically and/or
functionally unstable, or it is not; there is nothing to be gained by looking at
it.
The careful clinical assessment of the
functional stability of an injured ligament is far more valuable than expensive
imaging techniques, such as magnetic resonance imaging (MRI) or computerised
tomography (CT) scans, which can be very misleading. No one would consider
buying a second hand car from a picture as you cannot tell how well a car goes
merely by looking at it. The old rust bucket may look fit for the scrap heap hut
will drive surprisingly well, whereas the ‘top of the range’ model with all
the extras will not even start! In the same way, tissues that appear to be
damaged on scans may ‘drive’ perfectly well and normal looking tissues may
be functionally useless.
Nevertheless, in some situations when a
diagnosis is in doubt or there is an unusual presentation of pathology, then
arthroscopy and MRI have their place. Identification of meniscal and ligament
damage in the knee is 85 per cent accurate using both these techniques and is
invaluable in selected cases.