This In Brief review examines the two arthroscopic classification systems for partial-thickness rotator cuff tears. It traces their origin from Neer's impingement stages and evaluates how reliably each classifies tear location and grade. The focus is on whether these systems are trustworthy enough for clinical and research use.
The practical takeaway is a decision rule about trust: use these classifications only to answer "full or partial?" and nothing more. When you read an operative note that grades an Ellman or Snyder tear, treat the location and grade as unreliable labels, not hard data. Agreement for grading partial tears was near chance (k = -0.11 on MRI, 0.19 on arthroscopy).
The reason matters for boards: Ellman's depth cutoffs assume a uniform 10-12 mm tendon, but real tendon thickness varies, and Snyder never specified which dimension his size cutoffs measure. One clinically useful piece survives: bursal-sided tears cause functional impingement from bursal edema, which is why they are an indication for subacromial decompression while articular-sided tears are not.
Because you cannot predict the grade preoperatively, plan for all degrees of partial tear before starting the case.
This In Brief review examines the two arthroscopic classification systems for partial-thickness rotator cuff tears. It traces their origin from Neer's impingement stages and evaluates how reliably each classifies tear location and grade. The focus is on whether these systems are trustworthy enough for clinical and research use.
The practical takeaway is a decision rule about trust: use these classifications only to answer "full or partial?" and nothing more. When you read an operative note that grades an Ellman or Snyder tear, treat the location and grade as unreliable labels, not hard data. Agreement for grading partial tears was near chance (k = -0.11 on MRI, 0.19 on arthroscopy).
The reason matters for boards: Ellman's depth cutoffs assume a uniform 10-12 mm tendon, but real tendon thickness varies, and Snyder never specified which dimension his size cutoffs measure. One clinically useful piece survives: bursal-sided tears cause functional impingement from bursal edema, which is why they are an indication for subacromial decompression while articular-sided tears are not.
Because you cannot predict the grade preoperatively, plan for all degrees of partial tear before starting the case.