Clinical differences between patients with early and late revision surgery for symptomatic failed arthroscopic rotator cuff repair

Purpose: Time ranges of revision rotator cuff surgeries after arthroscopic repair are highly variable. However, the cause and clinical relevance of the different timings of revision surgeries have not been analyzed. The purpose of this study was to evaluate the clinical manifestations of patients who required revision surgeries at early and late periods after failed arthroscopic rotator cuff repair, and to identify clinical and radiological differences related to the timing of revision surgery. Methods: Sixty patients who underwent revision surgery due to symptomatic failed rotator cuff repair after arthroscopic repair were included. Patients were divided into two groups: patients who underwent revision surgeries within 1 year postoperatively (21 patients, group I) and patients who underwent revision surgeries more than 1 year postoperatively (39 patients, group II). Clinical and radiological characteristics were compared between the two groups before primary and revision surgery. Results: VAS for pain (5.9 ± 1.9 in group I, 3.9 ± 1.4 in group II, P < 0.001) and Constant score (50.7 ± 9.9 in group I, 60.4 ± 8.9 in group II, P < 0.001) at the time of revision surgery were significantly different between the two groups. In group II, isometric muscle strength of forward flexion (74.1 ± 21.1 to 63.9 ± 15.1, P = 0.020) and external rotation (73.0 ± 23.5 to 61.2 ± 15.0, P = 0.032) were significantly deteriorated after primary surgery, even with significant improvement of pain and shoulder function (VAS: 5.7 ± 1.9 to 3.9 ± 1.4, P < 0.001; Constant score: 50.3 ± 11.0 to 60.4 ± 8.9, P < 0.001). On postoperative MRI, re-tear at the tendon–bone interface on the greater tuberosity occurred significantly more in group I (81.0%) than group II (51.3%, P = 0.024). Incidence of full-thickness tear of the subscapularis tendon was significantly different between the two groups (42.9% in group I, 12.8% in group II, P = 0.012). Conclusion: Patients who had early revision surgeries had significantly worse clinical outcomes after primary surgery than patients who had late revision surgeries. Healing failure at the tendon–bone interface on the greater tuberosity and re-tear combined with full-thickness tear of subscapularis tendon were related to early revision. Conversely, patients of the late revision group had muscle weakness that considerably impacted daily activities, even with improved pain and shoulder function. Level of evidence: III.