The Correlation between Variation of Labral Attachment and Lesions of the Long Head of the Biceps Tendon in Patients with Rotator Cuff Tears.

OBJECTIVE
There was no universally accepted classification system that describes LHBT lesions as a type of its' pathology in patients with shoulder pain. This study aimed to determine the correlation of anatomic variants of glenoid labrum attachment of long head of biceps tendon (LHBT) and to assess their association, if any, with its lesions in rotator cuff tear (RCT) patients.


METHODS
All RCT patients from January 2016 to December 2019 were assessed arthroscopically to classify the LHBT labrum attachment according to its' anatomical location. A simplified classification was created to describe the LHBT as normal, tendinitis, subluxation or dislocation, partial tear and superior labral tear from anterior to posterior (SLAP) lesion beyond type II The RCT were classified as three types as partial, small to medium and large to massive. The correlation of variants of LHBT labral attachment with type of LHBT lesions in different RCT groups was evaluated.


RESULTS
In total, 669 patients were included for evaluation. The attachment of the LHBT was entirely posterior in 23 shoulders (3.4%), posterior-dominant in 81 shoulders (12.1%), and equal in 565 shoulders (84.4%). In equal distribution LHBT attachment group, age > 60 (odds ratio: 2.928, P < 0.001) and size of RCT (P < 0.001) were significant risk factors of LHBT lesions. In the analysis of all patients, comparing with the partial thickness rotator cuff tear (PTRCT), the odds ratio of small to medium RCT and large to massive RCT was 2.398 and 6.606 respectively. In addition, age > 60 (odds ratio: 2.854, P < 0.001) and size of RCT (P < 0.001) were significant risk factors of LHBT lesions. In posterior dominant group, size of RCT was a significant risk factor of LHBT lesions but not any others (P < 0.001). In entirely posterior group, no risk factor of LHBT lesions was found. It showed that the variation of LHBT attachment was not a significant risk factor of LHBT lesions in rotator cuff repaired patients (p = 0.075).


CONCLUSIONS
There are three types of LHBT labrum attachment in RCT patients on arthroscopic observation. 84.4% were equal distribution of LHBT attachment on glenoid labrum, followed by posterior-dominant (12.1%) and entirely posterior type (3.4%) in present study. Although the variation of LHBT attachment was not a significant risk factor of LHBT lesion in rotator cuff repaired(RCR) patients, there were different risk factors among three LHBT labral attachment types. In RCR patients, age > 60 and RCT size were significant risk factors of LHBT lesions.