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.