Predictors of pain development for contralateral asymptomatic degenerative rotator cuff tears based on features of an ipsilateral painful cuff tear: a prospective longitudinal cohort study

Abstract

Prior rotator cuff disease natural history studies have focused on tear-related factors that predict disease progression within a given shoulder. The purpose of this study is to examine both patient and tear-related characteristics of a painful rotator cuff tear that predict future pain development and functional impairment in a shoulder with a contralateral asymptomatic cuff tear. This is prospective longitudinal cohort study of subjects ≤65 years who underwent surgery for a painful degenerative rotator cuff tear and possessed an asymptomatic contralateral tear. Subjects were followed prospectively with shoulder ultrasound, physical examination and functional score assessment. Primary outcome was change in ASES score at 2 years. Secondary outcomes included WORC, PROMIS, HADS depression/anxiety, and VR-12 mental component scores. Sixty-five subjects were included with mean follow-up 37 (range 24-42) months. Seventeen (26%) developed contralateral shoulder pain at median 15.2(10.5) months. No difference in age, sex, CCI, occupational demand noted between subjects who did and did not develop pain. In the presenting painful shoulder there was no difference in baseline tear size, muscle degeneration, or biceps pathology between groups. The mean baseline tear length (8.6 vs. 3.8 mm, p=0.0008) and width (8.4 vs. 3.2 mm, p=0.0004) were larger in asymptomatic shoulders that subsequently developed pain compared to those that did not. However, there was no difference mean tear enlargement (length p=0.51, width p=0.90). There were no differences in baseline ASES, WORC, PROMIS scores or HADS depression/anxiety scores between shoulders that did and did not develop pain; however, subjects who developed pain reported lower baseline VR-12 MCS scores (53.3 vs 57.6, p=0.04). Shoulders that developed pain had higher VAS pain scores (2.9 [2.5] vs. 0.6 [1.0], p=0.016, lower ASES scores (7 [33] vs. 100[11.6], p=0.001) and significant changes in all WORC scales with pain onset compared to those that remained asymptomatic. There was no significant difference in changes of HADS anxiety/depression scores but a significant increase in VR-12 MCS scores in subjects who developed pain (7.1[12.6] vs. -1.9[8.7], p=0.036). A quarter of patients with painful cuff tear developed pain in a contralateral asymptomatic cuff tear that resulted in a measurable decline in function within 3 years. Analysis showed only baseline tear size of the asymptomatic shoulder was predictive of pain development. There were no tear-related features of the presenting painful rotator cuff tear or indices of mental health and physical function/occupational demand that were predictive of future pain development at short-term follow-up.