Long Term Non-Operative Management
Strong evidence supports that patient reported outcomes (PRO) improve with physical therapy in symptomatic patients with full thickness rotator cuff tears. However, the rotator cuff tear size, muscle atrophy, and fatty infiltration may progress over 5 to 10 years with non operative management.

Rationale

Two prospective randomized controlled trials comparing physical therapy to operative repair for treatment of small to medium rotator cuff tears have showed that physical therapy can result in clinical improvements, but the rotator cuff tears continue to enlarge with time. (Moosmayer 2014, Kukkonen 2015) In 37% of the rotator cuff tears treated with physical therapy in whom the tear size increased > 5 mm over five years; tear progression did not occur (0/60) in the repaired group (Moosmayer 2014) At 2-years, Kukkonen, et.al., reported that the tears treated with physical therapy instructed home exercise program enlarged from an average of 9.6 mm to 11.7 mm, while the repaired tendons tear size decreased from 8.4 mm to 4.2 mm (p<0.01). (Kukkonen 2015) After an average of 8.8 years, patients who were treated non-operatively showed substantial muscle atrophy in 49% (18/37) and fatty infiltration in 41% (15/37). (Moosmayer 2017)

Risks and Harms of Implementing this Recommendation
Patients treated non-operatively are at risk for reduced strength with rotator cuff tear progression. Moosmayer, et.al., compared patients treated with physical therapy that had an increase the tear size ≤ 5mm to those that progressed to > 5mm and reported the > 5mm group showed a loss of strength (between-group difference of 4.2 kg, p=0.02). (Moosmayer 2014) In a prospective cohort study, the Constant score was 81points for patients with tear size increases < 20 mm compared to 58.5 points in those ≥ 20 mm (p=0.008). (Moosmayer 2017) Patients who select physical therapy should be informed that over a 9 year period their tear size may progress and this could lead to a substantial decline in their perceived and measurable outcome.

Future Research
Continued long term comparative studies between physical therapy and surgical repair investigating larger tear sizes with pre-and postoperative advanced imaging studies. It is still unclear what factors influence tear progression and if tear progression advances enough to preclude future repair and subsequent resolution of symptoms.