From the Guidelines
Bicep tendon rupture is indeed associated with amyloidosis, as evidenced by the presence of unexplained biceps tendon rupture as a diagnostic criterion in cardiac amyloidosis 1. Amyloidosis is a condition characterized by the abnormal deposition of amyloid proteins in tissues throughout the body, including tendons. These protein deposits can weaken tendon structure over time, making them more susceptible to tears or complete ruptures. In amyloidosis patients, spontaneous tendon ruptures may occur with minimal trauma or normal use, with the biceps tendon being one of the potential sites affected. The mechanism involves infiltration of amyloid fibrils into the tendon tissue, which disrupts the normal collagen architecture and reduces tensile strength. Some key points to consider in the association between bicep tendon rupture and amyloidosis include:
- Unexplained biceps tendon rupture, particularly in the absence of trauma, can be a diagnostic clue for cardiac amyloidosis 1
- The presence of amyloid deposits in tendon tissue can lead to structural weakening and increased risk of rupture
- Patients with amyloidosis who experience sudden shoulder or arm pain, weakness, or visible deformity (such as a "Popeye muscle") should be evaluated for possible biceps tendon rupture
- Treatment of biceps tendon rupture in the context of amyloidosis typically involves a multidisciplinary approach, including management of the underlying amyloidosis to prevent further tendon and other organ damage 1
From the Research
Association Between Bicep Tendon Rupture and Amyloidosis
- Bicep tendon rupture has been associated with amyloidosis in some studies, particularly in patients with wild-type transthyretin cardiac amyloidosis 2.
- A study found that as many as one-third of patients with heart failure secondary to systemic, wild-type transthyretin amyloidosis have an associated distal biceps tendon rupture 3.
- However, another study found that younger patients with acute traumatic distal biceps tendon ruptures do not appear to be uniquely at risk for amyloid deposition at the time of tendon repair 3.
Musculoskeletal Manifestations of Amyloidosis
- Amyloidosis can present with various musculoskeletal disorders, including carpal tunnel syndrome, trigger finger, flexor tendon contracture, spontaneous tendon rupture, and pathological fracture through amyloid bone cysts 4.
- A systematic review found that amyloid deposition was reported in several musculoskeletal pathologies, including carpal tunnel syndrome, hip and knee osteoarthritis, lumbar spinal stenosis, and rotator cuff tears 5.
- The review also found that subtyping of the amyloid can enable diagnosis of systemic light-chain or transthyretin amyloidosis prior to cardiac manifestations 5.
Prevalence of Amyloid Deposition in Bicep Tendon Rupture Patients
- A study found that only 1 out of 30 patients with acute traumatic distal biceps tendon ruptures had evidence of amyloid deposition in the tendon 3.
- The study suggests that larger registry studies may be necessary to define the risk of developing cardiac amyloidosis years after sustaining an acute distal biceps tendon rupture 3.