The role of elbow positioning on arthroscopic assessment of the long head of biceps tendon in the beach chair position

BACKGROUND: Tendinopathy of the long head of biceps (LHB) tendon is a common cause of anterior shoulder pain and dysfunction. The extra‐articular portion within the bicipital groove undergoes frequent load and friction during shoulder movements and pathology within this area is frequently missed during arthroscopic assessment. METHODS: We quantified the arthroscopically assessable length of tendon within the shoulder in 14 consecutive patients undergoing subpectoral biceps tenodesis. After biceps tenotomy at the superior labrum, the tagged tendon was maximally tensioned and marked at the biceps outlet with the elbow in extension and flexion. The distance in distance between the two were measured. RESULTS: Mean distance from the superior labral insertion of the biceps to the outlet was 16.4 ± 4.1 mm (range, 11–25). With tension on the biceps with elbow extension, the mean measurable distance was 31.3 ± 6.7 mm (range, 19–45). With elbow flexion, this increased to 39.5 ± 5.9 mm (range, 25–52). Mean increase in visible tendon length was 8.2 ± 4.3 mm (range, 5–21) (p = 0.002). CONCLUSION: Elbow flexion results in an average increase of 26.2% more extra‐articular tendon visualized at arthroscopy. Therefore, we believe that elbow flexion is a useful adjunct, especially when performed in conjunction with techniques that pull the tendon into the joint, thus allowing for more complete arthroscopic assessment of the LHB, increasing detection of symptomatic biceps tendonitis. Level of evidence: Level IV.