Evaluation of Survivorship of Asymptomatic Degenerative Rotator Cuff Tears in Patients 65 Years and Younger: A Prospective Analysis with Long-Term Follow Up.

Abstract

The purpose of this prospective study is to describe the mid to long-term natural history of untreated asymptomatic degenerative rotator cuff tears in patients 65 years and younger. Subjects with an asymptomatic rotator cuff tear in one shoulder and a contralateral painful cuff tear age 65 years or younger were enrolled in a previously described prospective longitudinal study. Annual physical and ultrasonographic evaluations and surveillance for pain development were performed utilizing independent examiners for the asymptomatic shoulder. Two hundred twenty-nine subjects (mean age 57.1 years) were followed for a median of 7.1 (range 0.3-13.1) years. Tear enlargement occurred in 138 (60%) shoulders. Full-thickness tears were at greater risk for enlargement compared to partial-thickness (HR=2.93, 95%CI 1.71-5.03, p<0.0001) and control shoulders (HR=18.8, 95%CI 4.63-76.1, p<0.0001). Mean survival rates from Kaplan-Meier analyses indicate that full-thickness tears enlarged earlier (mean 4.7, 95%CI 4.1-5.2 years) than partial-thickness (mean 7.4, 95%CI 6.2-8.5 years) and control shoulders (mean 9.7, 95%CI 9.0-10.4 years). Tear presence in the dominant shoulder was associated with a greater enlargement risk (HR=1.70, 95%CI 1.21-1.39, p=0.002). Patient age (p=0.37) and gender (p=0.74) were not associated with tear enlargement. The 2,5 and 8-year survivorship free of tear enlargement for full-thickness tears was 74%, 42% and 20%, respectively. Shoulder pain developed in 131 (57%) shoulders. Pain development was associated with tear enlargement (HR=1.79, 95%CI 1.24-2.58, p=0.002) and was more common in full-thickness tears compared to controls (p=0.0003) and partial tears (p=0.01). An analysis of progression of muscle degeneration was performed 138 shoulders with full-thickness tears. Tear enlargement was seen in 104 of 138 (75%) of these shoulders during follow-up (median 7.7 [6.0] years). Progression of muscle fatty degeneration was seen in the supraspinatus in 46 (33%) and the infraspinatus in 40 (29%) shoulders. Adjusting for age, both the presence of fatty muscle degeneration and the progression of muscle changes for both the supraspinatus (p<0.0001) and infraspinatus (p<0.0001) muscles were associated with tear size. For both the supraspinatus (p=0.03) and infraspinatus (p=0.03) muscles, tear enlargement was significantly associated with progression of muscle fatty degeneration. Anterior cable integrity was significantly associated with the risk of muscle degeneration progression for both the supraspinatus (p<0.0001) and the infraspinatus (p=0.005) muscles. Asymptomatic degenerative rotator cuff tears progress in patient 65 years and younger. Full-thickness rotator cuff tears have a higher risk of continued tear enlargement, progression of fatty muscle degeneration and pain development than partial-thickness tears.