Influence of pre-operative tear size and tendon retraction on repair outcomes for isolated subscapularis tears.

PURPOSE: The purpose of this study was to investigate the influence of tendon tear size, in terms of length and retraction, on clinical and anatomic outcomes following repair for isolated subscapularis tears.

METHODS

The records of 47 consecutive repairs of isolated subscapularis lesions were studied to correlate pre-operative tear characteristics with clinical and radiographic outcomes.

RESULTS

Forty patients had complete radiographic outcomes at 3.2 ± 1.1 years, of which 36 had complete clinical outcomes at 3.5 ± 0.9 years. Re-tears were observed in five shoulders (12.5 %). Fatty infiltration increased by one grade in 20 shoulders (50 %), and by two grades in four shoulders (10 %). Pre-operative tear size was associated with the post-operative belly-press test (BPT) (p = 0.042) and fatty infiltration (p = 0.051). Pre-operative tendon retraction was associated with post-operative BPT (p < 0.001) and fatty infiltration (p = 0.023).

CONCLUSIONS

Our results do not entirely prove that prognostic factors used for superior and posterior tendon tears apply for the subscapularis. Pre-operative tendon retraction is a better predictor of outcomes than tear size. When tear size and tendon retraction are simultaneously severe, re-tears and poor outcomes are more likely.