Key Information
Source
Year
2026
summary/abstract
Introduction
Transthyretin amyloidosis (ATTR) is a major type of systemic amyloidosis resulting from misfolding of transthyretin (TTR) monomers, TTR aggregation into insoluble amyloid fibrils, and extracellular fibril deposition in various tissues and organs [1], [2], [3]. TTR protein misfolding and amyloid fibril deposition in the heart lead to irreversible deterioration of myocardial function, progressing to heart failure and death. Transthyretin amyloidosis cardiomyopathy (ATTR-CM) is increasingly recognized as a cause of heart failure in older patients, with an estimated median survival of approximately 3.5 years without treatment [1]. Grade 2 or 3 myocardial uptake of radiotracer isotope during bone scintigraphy is a valuable, non-invasive tool indicating a diagnosis of ATTR-CM when monoclonal gammopathy is excluded [1]. ATTR amyloidosis exists in two distinct forms that may involve the heart: the hereditary variant (ATTRv) and the age-related wild-type (ATTRwt). Differentiation between these forms requires genotyping [1]. In both forms, the amyloidogenic process begins with the destabilization of the tetrameric structures of TTR into folded monomers, which then transform into amyloid fibrils [1], [4].
Although prognosis is largely centered on myocardial involvement, ATTR amyloidosis is a systemic disorder, also characterized by amyloid deposits in other organs, including musculoskeletal tissues, particularly ligaments, synovia, and joint cartilage [3]. Non-cardiac musculoskeletal manifestations such as carpal tunnel syndrome (CTS) typically appear years in advance of cardiac signs of ATTR amyloidosis [5], [6]. CTS is the most common manifestation, found in up to 87% of patients, and its presentation can precede diagnosis of amyloidosis by up to 12 years [7], [8]. Other musculoskeletal conditions commonly observed early in the disease course should alert rheumatologists and orthopedic surgeons to the possibility of underlying ATTR amyloidosis [3]. The implementation of screening strategies is crucial given that ATTR-CM can now be treated. Early treatment has been demonstrated to significantly improve prognosis, with better cardiac outcomes and longer survival [1], [9]. Rheumatologists and orthopedic surgeons therefore have a key role in the early detection of ATTR amyloidosis and in improving the diagnostic and therapeutic pathway, but their awareness appears suboptimal [10]. This narrative review aims to examine the various musculoskeletal disorders associated with ATTR amyloidosis, to assess the extent to which their recognition by rheumatologists and orthopedic surgeons can promote early diagnosis and treatment of ATTR heart disease, to define the indications for histologic examination in patients at risk of having ATTR-CM, and to propose appropriate follow-up measures for patients in whom amyloidosis is discovered during musculoskeletal surgery.