Case Report: Absence of the Long Head of the Biceps Brachii Tendon.

BACKGROUND: Absence of the long head of the biceps brachii (LHB) tendon is rare with an unknown incidence. It can occur bilaterally in patients with or without associated congenital anomalies. Diagnostic difficulty exists with both magnetic resonance imaging and physical examination. METHODS/RESULTS: We present the case of a 24-year-old female with a three year history of progressive right shoulder pain and instability with negative magnetic resonance arthrogram who was subsequently found to have absence of the LHB tendon. CONCLUSIONS: There may be a potential relationship between absence of the LHB tendon and an increased risk of acquired shoulder pain and instability. However, the relationship between the absence of the LHB and subsequent pain and function remains unclear. LEVEL OF EVIDENCE: Level IV.