Pain and stiffness in partial-thickness rotator cuff tears.

To evaluate the null hypothesis of no difference in degree of pain or stiffness between patients with partial- and full-thickness tears of the rotator cuff, we measured pain and stiffness in a cohort of consecutive patients who underwent arthroscopy for rotator cuff-related conditions. Pain was measured with a visual analogue scale, and range of motion was measured with a goniometer. Included in the study were 410 shoulders (410 patients), of which 214 had no tear, 66 had articular-sided partial-thickness tears, and 83 had single-tendon full-thickness tears. There was no statistical difference for measurements of pain or stiffness between patients with partial- and full-thickness tears, and hence the null hypothesis was upheld. Neither pain nor stiffness should be used as a diagnostic indicator for differentiation of partial- and full-thickness rotator cuff tears.