Tendon Pathology or Paratenon?

Tendinitis? "Inflammation"

Tendinopathy? "Something's wrong"

Tendinosis? "Diseased tissue"

Franklyn-Miller et al recently published an editorial piece entitles "Fasciitis first before tendinopathy: does anatomy hold the key?" in the most recent issue of British Journal of Sports Medicine outlining the fact that most research articles have failed to mention the role of the enveloping fascia in tendon pathologies. Specifically, they state that in some conditions involving musculotendinous structures, inflammation of the fascia is actually present, similar to that of conditions such as plantar fasciitis 

Their argument stems from histological evidence of inflammatory infiltrates, the presence of a fascia-tendon interface, and the relatively high number of studies that make reference to the presence of a paratenon enveloping or overlying the Achilles tendon. In fact, this paratenon is actually the posterior fascia of the lower extremity! Note: this paratenon is frequently used as a landmark for guidance of therapeutic injections of the Achilles tendon. 

Therefore, this posterior fascia or paratenon, may be  a source of pain and inflammation in very early stage "tendon" pathologies and adhesion of this structure to its underlying tendon may actually lead to abnormal tendon loads and subsequent tendinopathy.

Finding the root cause of pain local to a specific area is perhaps one of the most important, yet difficult, skills of a clinician. Therefore, it may be wise to occasionally ask ourselves do we really know what we think we know?