Diagnosis of subscapularis tendon tears: are available diagnostic tests pertinent for a positive diagnosis?

Abstract

Hypothesis: Clinically, subscapularis tendon tears are suggested by the presence of increased passive external rotation compared to the opposite side, resisted internal rotation manoeuvres (Lift-Off test [LOT], Belly-Press test [BPT], Napoleon test and Bear-Hug test [BHT] and positive Internal Rotation Lag Sign and/or Belly-Off Signs). Associated bicipital involvement is frequent with subscapularis tendon tears, because it participates in the formation of the biceps pulley. The Palm-Up test (PUT) is used for the biceps, and the Jobe test for the supraspinatus.

Material and methods: In this multicenter study, we evaluated the positive diagnostic value of the clinical tests, LOT, BPT, BHT, PUT, and the Jobe test for subscapularis tears as well as their anatomical value. The relationships of the different parameters studied were compared statistically by analysis of variance (ANOVA). This prospective multicenter study was performed from January 2009 to February 2010 and included 208 cases of subscapularis tendon tears, isolated or associated with partial (Ellman 1, 2 or 3) or full thickness (SFA stage 1) supraspinatus tears.

Results: The severity of the subscapularis tear was quantified according to the SFA classification into four stages and according to the level of injury (the lower 1/3 and upper 2/3). The three tests LOT, BPT and BHT were correlated to the severity of observed tears (P<0.05). The more deficient the test results were, the more severe the anatomical damage. The LOT is the test that cannot be performed most often (18%) but when it is positive, it is predictive of very severe tears. The BHT is the most sensitive of all tests (82%). The frequency of biceps involvement was correlated to the severity of subscapularis damage. There was no significant correlation between biceps involvement and subscapularis tests, or between supraspinatus involvement and subscapularis tests. There was no correlation between the Palm-Up test and subscapularis tears with associated supraspinatus involvement however, it was significantly correlated to biceps involvement (P<0.05). The Jobe test was disappointing because it was often positive even for isolated subscapularis tears.

Conclusion: Even though all three tests were performed (LOT, BPT, BHT), 24% of the subscapularis tears were only diagnosed during surgery. The role of the Internal Rotation Lag Sign and Belly-Off Sign in improving the diagnosis of tears was not studied in this work.