Anatomic factors associated with partial distal biceps tendon tears: a comparative control study.

Area of Science:

• Orthopedic Surgery
• Radiology
• Anatomy

Background:

• Limited literature exists on anatomical factors contributing to partial distal biceps tendon (DBT) tears.
• A hypothesis suggests larger radial tuberosities and reduced radioulnar space during pronation may cause mechanical impingement, predisposing to DBT tears.

Purpose of the Study:

• To investigate anatomical factors associated with partial DBT tears.
• To retrospectively review DBT anatomy in elbows with and without tears using 3-T MRI.

Main Methods:

• Retrospective review of 3-T MRI scans from 26 elbows with partial DBT tears and 30 normal elbows.
• Measurements included radial tuberosity dimensions, radioulnar space, and radial tuberosity-ulnar space.
• Analysis also noted enthesophytes and single vs. double DBT configurations.

Main Results:

• Elbows with partial DBT tears exhibited significantly larger radial tuberosity length and thickness.
• These elbows also showed significantly smaller radioulnar and radial tuberosity-ulnar spaces.
• A larger ratio of radial tuberosity thickness to radial diameter, presence of enthesophytes, and double DBTs were associated with tears.

Conclusions:

• Larger radial tuberosities and smaller intervening spaces are associated with partial DBT tears.
• These anatomical variations may lead to chronic impingement and tendon delamination, causing tears.
• Enthesophytes and specific double DBT configurations are also linked to partial DBT tears, aiding in understanding pathogenesis.