Figure 23. Reproduction of page 101 from E. A. Codman's classic textbook (25) shows partial-thickness undersurface tears of the rotator cuff. Figure 1 demonstrates a subtle, undersurface lesion located at the capsular reflection. Figure 2 shows a more extensive, partial undersurface tear that involves approximately 50% of the cuff thickness ("rim-rent"). Figure 3 shows a yet more extensive partial, undersurface tear with delamination and retraction of the undersurface contribution (straight arrow). Figure 4 shows a lesion confined predominantly to the cuff substance. The secondary osseous changes are most conspicuous in Figures 2 and 3 (curved arrows).