67. ASSOCIATION BETWEEN THE UPWARD MIGRATION INDEX AND FUNCTIONAL AND QUALITY OF LIFE OUTCOMES IN ARTHROSCOPIC ROTATOR CUFF REPAIR

Abstract

Purpose: The upward migration index (UMI) is a useful radiographic parameter for assessment of disorders of the rotator cuff. Utility of the UMI as a prognostic indicator for outcome following cuff repair has not been previously studied. The objective of this study was to determine if an association exists between the pre-operative UMI and the improvement in clinical and quality of life outcome scores following arthroscopic rotator cuff repair.

Method: Patients with a full thickness tear of the rotator cuff who underwent an arthroscopic repair of the cuff were selected for review. Eighty-four patients were included in the series. Mean patient age was 55 (range 25–78). The UMI was measured by MRI, and patients were divided into three groups: < 1.25 (GROUP A), 1.25–1.35 (GROUP B) and > 1.35 (GROUP C). Outcome variables were the non-weighted Constant-Murley score, ASES and the WORC assessed at baseline, 6 month and 12 months post-operatively. The paired t-test was used to carry out comparisons in follow up and one-way ANOVA was used to carry out comparisons between groups.

Results: There were 9 patients in group A, 33 in group B and 42 in group C. The improvement in scores from baseline to 1 year were as follows: ASES; 21.1 (A), 32.6 (B), and 38.4 (C); Constant 21.4 (A) 19.8 (B), and 24.2 (C) and WORC 31.9 (A), 42.7 (B), and 44 (C). Statistically significant improvements were observed in all groups in all outcome measures from baseline to 6 months and from 6 months to 1 year. Although the differences were not statistically significant (p> 0.05), a trend toward greater improvement in outcomes was observed with higher upward migration indices.

Conclusion: A lower UMI was associated with less improvement in functional and quality of life outcomes following arthroscopic rotator cuff repair, although these differences were not statistically significant. Patients with a low UMI demonstrated a significant improvement in functional and quality of life scores following surgery. In isolation, a low UMI should not represent a significant contraindication to treatment by arthroscopic rotator cuff repair.