The Prevalence of Tear Patterns and Their Effects on Tendon Healing After Arthroscopic Surgery in Patients With Full-Thickness Rotator Cuff Tears

Background: To achieve successful anatomic rotator cuff repair with minimal tension, both the tear pattern and tear size should be considered. However, little information is available concerning the frequency of tear patterns and their effects on tendon healing. Purpose: To evaluate the distribution of tear patterns in full-thickness rotator cuff tears and whether these patterns affect tendon healing after arthroscopic repair. Study Design: Case-control study; Level of evidence, 3. Methods: Between 2014 and 2021, patients who underwent arthroscopic surgery for symptomatic full-thickness rotator cuff tears with a minimum 2-year follow-up with postoperative magnetic resonance imaging or ultrasound were retrospectively reviewed. After the debridement of degenerative tendon tissue during arthroscopic surgery, the tear pattern was classified as crescent, U, or anterior or posterior L shaped. Intergroup differences in clinical and radiological characteristics were analyzed. In the subgroup analysis, patients were divided into 2 subgroups: small-to-medium or large-to-massive tears. Results: Among the 1037 patients with a full-thickness rotator cuff tear, the most common tear pattern was crescent shaped (39.6%), followed by posterior L, U, and anterior L shaped (26.0%, 21.4%, and 12.9%, respectively). In the subgroup analysis, 713 patients (68.8%) had small-to-medium tears, while 324 (31.2%) had large-to-massive tears. The proportion of large-to-massive tears was significantly higher for the anterior L-shaped tear pattern than for the other tear patterns (24.8%, 28.8%, 52.2%, and 32.6% for crescent, U, and anterior and posterior L shaped, respectively; P <.001). The anterior L-shaped tear pattern had a significantly higher retear rate than the other tear patterns in small-to-medium tears (7.8%, 13.0%, 28.0%, and 10.6% for crescent, U, and anterior and posterior L shaped, respectively; P <.001). The rate of revision surgery because of a symptomatic retear within 2 years after primary surgery was significantly higher for the anterior L-shaped tear pattern than for the other tear patterns (3.8%, 7.5%, 21.6%, and 0.0% for crescent, U, and anterior and posterior L shaped, respectively; P =.002). Conclusion: The prevalence of tear patterns varied depending on the tear size. In small-to-medium tears, the anterior L-shaped tear pattern had the lowest incidence among the tear patterns; however, it had a significantly higher retear rate. Furthermore, the anterior L-shaped tear pattern had a higher incidence of retears requiring early revision surgery than the other tear patterns.