“…Therefore, the resulting area calculation assumes a square, 2-dimensional tear shape, while shape variations in individual tear defect configurations exist. Still, the authors felt that the arthroscopically determined square centimeter measurements of tear size were an improvement over other methods, such as nonquantitative, unidirectional, or solely derived from magnetic resonance imaging, to describe rotator cuff tear size 25 , 26 , 27 and allowed the authors to reproducibly define both the initial and residual rotator cuff tear defects that were present. Also, the arthroscopic measurements were taken to an accuracy of 1 cm, thus introducing a “rounding error” that contributes to inaccuracy within the tear area calculation.…”