Radiological and clinical evaluation of long head of biceps tendon function in the glenohumeral joint.

The aim of the study was to investigate the relationship between biceps pathologies and radiological measurements in massive rotator cuff tears treated arthroscopically. Between December 2015 and December 2018, a total of 145 patients (56 males, 89 females; mean age: 62.2±9.7 years; range, 28 to 87 years) with supraspinatus and/or infraspinatus full-thickness tear larger than 3 cm and who underwent arthroscopic rotator cuff repair were retrospectively analyzed. Biceps pathologies detected during arthroscopy were divided into four groups. Group 1: biceps tendinitis or without biceps pathology; Group 2: biceps partial/degeneration tear; Group 3: biceps dislocation/instability; Group 4: complete biceps head rupture. Radiological measurements were calculated from the preoperative magnetic resonance imaging and anteroposterior X-ray images of the patients. A total of 65.5% of the lesions were on the right arm and 34.5% were on the left arm. All patients had posterior superior rotator cuff tears which could be surgically repaired. A total of 22.1% of the patients had no biceps tendinitis/biceps pathology, 20.7% had biceps instability/dislocation, 28.3% had biceps degeneration/partial rupture, and 29% of patients had biceps total rupture. Patients in Group 4 had a statistically significantly higher superior migration of the humeral head distance (p=0.012) than Group 2, and patients in Group 2 had a statistically significantly higher coracohumeral distance (p=0.042) than patients in Group 4. There was no significant difference in the other measurements among the groups. The long head of the biceps, of which function has not yet been clearly elucidated, is one of the superior and anterior stabilizing forces of the humeral head.