Purpose: To analyze the relationship between functional outcomes and postoperative cuff integrity (anatomic outcome), and to reveal the factors affecting outcomes of rotator cuff repair.
Methods: Seventy-eight patients who had undergone repair of full-thickness rotator cuff tear received both computed tomographic arthrography (CTA) and functional evaluation a minimum of 1 year after surgery. The mean follow-up period was 19.6 months (range, 12 to 39 months). Anatomic outcome was evaluated by CTA. Functional outcomes were evaluated by visual analogue scale (VAS) for pain and satisfaction with the operation, Constant score, simple shoulder test (SST), and American Shoulder and Elbow Surgeons (ASES) score. Various clinical and structural factors were included for statistical analysis.
Results: All patients displayed significant improvement in all functional evaluations at the final visit. Functional outcome did not correlate with anatomic outcome (P > .05). A few variables did relate to functional outcome: female or old age statistically correlated with the score of SST, and the size of the tear correlated with the ASES score (P < .05). The retear was influenced by age, fatty degeneration of the cuff muscles, and the size of tear. Fatty degeneration of the infraspinatus was the most independent predictor of anatomic outcome on multivariate regression analysis.
Conclusions: Rotator cuff repair brought significant functional improvement. However, the functional outcome did not correlate with the anatomic outcome. The fatty degeneration of the infraspinatus muscle served as an independent predictor of the postoperative integrity of the rotator cuff.
Level of evidence: Level IV, prognostic case series.