Amyloidosis is a disorder where pathologically misfolded endogenous precursor proteins aggregate extracellularly. Cardiac involvement can lead to heart failure. Transthyretin (TTR) deposits are associated with carpal tunnel and trigger finger. Their symptoms can anticipate cardiomyopathy. Early diagnosis of amyloidosis TTR (ATTR) can improve patient's quality of life and life expectancy. The aim of this study is to screen patients with a recent story of CTS or trigger finger using known red flags, assessing their specificity and sensitivity.

We describe the early results of a double-center prospective observational study. Red flags for ATTR are concomitant CTS and trigger finger, bilateral CTS, recurrent CTS, multiple trigger finger, known cardiomyopathy. Exclusion criteria of the study are: recent trauma, rheumatologic disorders.

Tissue confirmation of amyloidosis is performed at the time of CTS or trigger finger surgery with biopsy of the tenosynovium or of the transverse carpal ligament. Positive patients are routed to a multidisciplinary diagnostic-therapeutic pathway.

We included 8 patients who underwent carpal tunnel release and 10 patients with trigger finger.

Mean age was 64 years old, 66% were male. A positive ATTR specimen was found in 47% of cases. Seven patients who underwent CTS were affected by bilateral CTS and 71.4% of them resulted in a positive ATTR biopsy. Only 10% of patients with already known cardiomyopathy but without any other hand affection (CTS, trigger finger) other than the elective surgery have shown positivity for amyloidosis. All the patients with bilateral CTS and concomitant multiple trigger fingers were found with a positive sample.

In literature almost 50% of patients with ATTR have a history of CTS. Bilateral manifestation is the most common association with amyloidosis and it is characterized by a high rate of CTS recurrence. On average, it precedes the cardiac involvement by five to ten years. Correlation of trigger finger with ATTR is well described in literature, although it is based on limited series. Patients with amyloid deposition had a higher number of digits affected on average compared with patients with a negative sample.

Very common hand disorders such as CTS and trigger finger are the earliest manifestations of ATTR. By identifying the red flags for amyloidosis, the hand surgeon can play an active role in early diagnosis and quick onset of disease modifying therapy. In our opinion, given the safe and cost effective profile of the biopsy, tissue specimen collection at the time of routine hand surgery procedures should be considered for selected patients.