Critical zone tear
A critical zone tear is referred to as a rotator cuff tear in the critical zone of the rotator cuff, described approximately 8-20 mm proximal of the insertion site.
Epidemiology
Common in adults and older people not so common in children and adolescents .
Clinical presentation
The clinical manifestation is wide-ranging, varying from mild distress to reduced throwing speed, chronic pain, and shoulder inability to move.
Pathology
Rotator cuff tears in the 'critical zone' are characterized by an intact insertional tendon stump. They can come in the full spectrum of possible rotator cuff tears: full-thickness, partial-thickness, intrasubstance, articular-sided, bursal-sided with or without intratendinous extensions.
Most critical zone tears are thought to be multifactorial in nature: degenerative and traumatic-related tears occur there. From its location, the zone is affected most by subacromial impingement and there is a debate about the vascularity in that specific location. Some newer theories promote a view of relative hypovascularity in the stage of tendinosis, hypervascularity in strain and smaller partial-thickness tears and again hypovascularity in full-thickness tears .
See also
