Paper #27 - Correlation of clinical outcomes of retear and tear progression after arthroscopic rotator cuff repair

Abstract

Background: Rotator cuff retear rate after arthroscopic cuff repair is still high despite advanced arthroscopic techniques and instrument evolution. Even if a retear occurs after rotator cuff repair, improvement in shoulder function is generally maintained, and it is known that rotator cuff integrity does not correlate with clinical outcomes. However, recent studies reported that clinical results of patients with a cuff retear are worse than those with a healed cuff. Therefore, functional outcomes of patients with rotator cuff retear are still on debate. This study evaluated factors related to clinical outcomes of rotator cuff retear after arthroscopic rotator cuff repair focusing on the importance of preoperative and postoperative changes of tear size. Materials and Methods: Four hundred and forty-two patients with full-thickness rotator cuff tear who underwent arthroscopic rotator cuff repair were included in this study. Patients who were possible to cover footprint completely, able to follow up over 2 years, and conducted postoperative MRI at 6 months for tendon integrity were included. The size of tear was measured on the oblique coronal and sagittal images of both preoperative and postoperative MRI. Intact tendon was defined as sufficient thickness of the repaired tendon showing continuity and a homogeneous low-intensity signal in the substance of cuff. Retear was defined as the repaired tendon showing complete discontinuity from footprint. Pain was measured by using VAS score, range of motion was recorded and functional outcomes were measured with ASES and Constant scores. Clinical outcomes were compared between patients with retears and intact cuff. Factors may affect clinical outcome such as preoperative tear size, changes of tear size and retear patterns were evaluated. Results: There were 233 males and 209 females with a mean age of 55 years (range; 46-75 years). Average follow-up period was 33 months (range 24-43 months). Fifty-eight patients (13.1%) had a retear confirmed by postoperative MRI. Patients with a healed cuff showed better shoulder functions than the patients with a retorn cuff (ASES; healed patients, 92.6 ± 9.5 and retear patients, 87.6 ± 12.4, P = .008). 1). Effect of preoperative rotator cuff tear size: In the patients with a preoperative large to massive size, patients with retear showed significant difference in functional outcomes (ASES: 86.5 ± 12.4 and Constant score: 88.7 ± 8.0) when compared with patients with a healed rotator cuff (ASES: 76.9 ± 9.7, P = .02 and 76.9 ± 11.7, P = .001). However, in patients with preoperative small and medium-sized tears, clinical outcomes were not significantly different irrespective of the status of healing of the cuff (ASES: healed cuff, 93.9 ± 7.8 and cuff retear, 93.8 ± 9.2 (P = .37), Constant score: healed cuff, 90.0 ± 11.7 and cuff retear, 91.5 ± 8.5 (P = .47)). 2). Comparative size of retear: Patients with smaller size of retear than the preoperative tear size (n = 28) showed significantly better functional outcomes and muscle strength recovery (Constant score: 90.5 ± 8.8) than those with equal or larger size of retear after surgery (n = 30) (Constant score: 83.7 ± 11.7, P = .025). 3). Retear pattern: Postoperative tear either at the footprint or at the musculotendinous junction did not influence the functional outcomes. 4). Risk factors for retear: Fatty degeneration more than grade 3 (odds ratio = 2.74, (CI: 1.19-6.36), P = .018) and preoperative large to massive rotator cuff tears (odds ratio = 2.2 (CI: 1.17-4.15), P = .015) were preoperatively affecting factors which were significant related to retear after surgery. Age at surgery, sex, symptom duration, arm dominance and associated pathology had no significant effect on the outcome of surgery. Conclusion: Preoperative large to massive rotator cuff tears, and fatty degeneration more than grade 3 are important contributing factors for retear after arthroscopic rotator cuff repair. Patients with preoperative small to medium sized tears had satisfactory clinical outcomes regardless of postoperative tendon integrity. However, in patients with a preoperative large to massive tear who develop retear, the functional outcomes are poorer than patients with a healed cuff. The patients with an equal or larger retorn tendon than preoperative size showed poorer Constant score and muscle strength regardless of preoperative sizes of tear. Therefore, surgeons should take more efforts and employ techniques to reduce the size of retear even if retear occurs.