The Relevant Anatomy of the Biceps Tendon When Performing Tenodesis in Filipino Cadaveric Specimens

Abstract

Background: Biceps tenodesis is a technique frequently performed in shoulder surgeries. Various techniques have been described, but there is no consensus on which technique restores the length-tension relationship. Restoration of the physiologic length-tension relationship has been correlated to better functional outcomes, such as decreased incidence of residual pain or weakness of the biceps. The objective of this study was to measure the anatomic relationship of the origin of the biceps tendon with its zones in the upper extremity. This would provide an anatomic guide or an acceptable placement of the tenodesis to reestablish good biceps tension during surgery. Methods: The study used nine adult cadavers (five males, four females) from the [withheld for blinded review]. Nine shoulder specimens were dissected and markers were placed at five points along each biceps tendon: (1) Labral origin (LO) (2) Superior bicipital groove (SBG) (3) Superior border of the pectoralis tendon (SBPMT) (4) Musculotendinous junction (MTJ) and (5) Inferior border of the pectoralis tendon (IBPMT). Using the origin of the tendon as the initial point of reference, measurements were made to the four subsequent sites. The humeral length was recorded by measuring the distance between the greater tuberosity and the lateral epicondyle as well as the tendon diameter at the articular surface. Results: The intraclass correlation coefficient was excellent across all measures. A total of nine cadavers were included. Mean age of patients was 66.33 years old, ranging from 52-82 years old. These were composed of five male and four female cadavers. The mean tendon length was 24.83mm ± 4.32 from the origin to the superior border of the bicipital groove, 73.50mm ± 6.96 to the Superior Border Pectoralis Major Tendon, 100.89mm ± 6.88 to the Musculotendinous Junction, and 111.11mm ± 7.45 to the Inferior Border Pectoralis Major Tendon. The mean tendon diameter at the articular origin was 6.44mm ± 1.76. Conclusion: This study provided measurement guidelines that could restore the natural length-tension relationship during biceps tenodesis using the interference screw technique in Filipinos. A simple method of restoring a normal length-tension relationship is by doing tenodesis close to the articular origin and creating a bone socket of approximately 25mm in depth, using the superior border of the bicipital groove as a landmark.