2023 ISAKOS Biennial Congress Paper
The Long Head Of the Biceps Tendon Does Not Provide A Clinically Significant Contribution To Anterior Glenohumeral Stability Even In the Setting of Glenoid Defects
Alexander Otto, MD, Neufahrn, Bavaria GERMANY
Lauren K Szolomayer, MD, Farmington, CT UNITED STATES
Joshua B. Baldino, PharmD, Newington, CT UNITED STATES
Mark P. Cote, PT, DPT, MSCTR, Farmington, CT UNITED STATES
ELIFHO OBOPILWE, ME, BSc, Farmington, Connecticut UNITED STATES
Andreas B. Imhoff, MD, Prof. Emeritus, Sauerlach / Munich, Bavaria GERMANY
Sebastian Siebenlist, MD, MHBA, Prof., Munich, Bavaria GERMANY
Augustus D. Mazzocca, MS, MD, Waltham, MA UNITED STATES
Julian Mehl, MD, Munich, Bavaria GERMANY
Department of Sports Orthopaedics, Technical University of Munich, Munich, Bavaria, GERMANY
FDA Status Cleared
Summary
This biomechanical study evaluated the stabilizing effect of the long head of the biceps tendon and observed no clinical relevant contribution to glenohumeral stability.
Abstract
Purpose
The long head of the biceps tendon (LHBT) has been implicated as a common source of pain in the shoulder, but there is no consensus as to its effect on glenohumeral stability. The purpose of this study was to investigate the stabilizing effect of the LHBT in anterior glenoid defect models to determine if it contributes to anterior glenohumeral joint stability.
Methods
Twenty-four fresh-frozen cadaveric shoulders (age 60.1 ± 8.6 years) were randomized to 3 different defect groups (isolated soft-tissue Bankart lesion, 10% anterior glenoid defect, 20% anterior glenoid defect) which were mounted in a shoulder-testing system allowing 6 degrees of freedom. Glenohumeral translation was measured in the vulnerable ABER position by a 3D-digitizer as the difference between the start and end positions in the XY-plane after an anterior force was applied. Each specimen was tested under 18 conditions: 3 glenoid states (native, defect, repair), 3 anterior loads (20 N, 30 N, 40 N), and 2 LHBT tensions (0 N, 10 N). A linear mixed-effects model was generated to determine the effect of LHBT tensioning on glenohumeral stability.
Results
LHBT load had a statistically significant, but negligible, effect on glenohumeral translation in the anterior-posterior direction, decreasing it by 0.03 mm/N (?2(1) = 5.87, p = 0.0154, 95% CI: [-0.06, -0.006]). There was no significant effect of LHBT tensioning in the superior-inferior direction.
Conclusion
In the context of soft tissue Bankart lesions and anterior glenoid bone defects up to 20%, load on the LHBT confers some anterior-posterior stability to the glenohumeral joint, although this effect is so small as to not be clinically significant. The LHBT does not contribute to superior-inferior stability. Consequently, biceps tenotomy or tenodesis is a viable treatment for biceps pain in the setting of concurrent instability with a low probability to increase adverse events as glenohumeral instability.