Evaluation of Biceps Tenotomy or Tenodesis on Fatty Infiltration of the Biceps Muscle.

The objective of the present study was to determine whether there is fatty infiltration (FI) of the biceps brachii muscle mass after tenotomy or tenodesis for the treatment of tendon injuries in the long head of the biceps and to establish a relationship between FI with changes in the length of muscle fibers.  Clinical and imaging analysis of 2 groups of patients (biceps tenodesis [16 patients] and biceps tenotomy [15 patients]). In both groups, we compared the findings on the contralateral side of each patient (control group). All patients had undergone unilateral biceps tenodesis or tenotomy, with postoperative follow-up of > 1 year. Magnetic resonance imaging (MRI) was performed on both arms of each patient following a specific protocol. Strength of elbow flexion was measured with a manual dynamometer, and the results were subjected to statistical analysis.  The mean postoperative period before the MRI was 5 years, and no case of FI was observed in the anterior compartment of either arm of the evaluated patients. Seven patients had moderate or severe deformity in the operated arm. We found no significant relationship between arm deformity (  = 0.077), flexion strength percentage (  = 0.07) or pain on palpation of the bicipital groove (  = 0.103).  None of the evaluated patients had evidence of FI in the muscle mass of the anterior arm compartment after the procedures. It was not possible to establish a correlation between the discrepancy of the biceps muscle length measured by MRI and the presence of FI in the anterior compartment of the arm.