Amyloid in Primary Hip Arthroplasty Specimens: An Opportunity for Early Detection of Amyloidosis?

BACKGROUND: Recent advances in pharmacologic therapies to treat amyloidosis demand renewed focus on early identification of patients who will benefit from these therapies. Incidental detection of amyloid in orthopaedic specimens has been previously described, but the clinical significance of these findings remains unclear. Modern techniques for amyloid detection and subtyping may identify clinically relevant amyloid in routine orthopaedic specimens. The purpose of this study was to assess the prevalence of amyloid in a unique contemporary cohort of total hip arthroplasty (THA) specimens using recently recognized histologic patterns of amyloid deposition.

METHODS: A retrospective study was performed of specimens from all primary THAs from January to March 2025 at a single institution. The prevalence of amyloid was assessed using Congo red staining in cases with suspected amyloid deposition on hematoxylin- and eosin-stained tissues, and amyloid subtyping was performed by mass spectrometry in a subset of samples. This was compared with the historical prevalence of amyloid in THA specimens from January 2021 to December 2023 at the same institution. There were 1,744 THA specimens included in the contemporary cohort and 15,680 in the historical cohort.

RESULTS: The prevalence of amyloid was higher in the contemporary than the historical cohort, with 73 (4.2%) cases of amyloid deposition identified in the contemporary cohort and nine (0.06%) in the historical cohort. There were 29 cases subtyped with mass spectrometry, identifying 11 cases of the cardiac-associated transthyretin subtype.

CONCLUSION: Historically, making the pathological diagnosis of amyloidosis was of little clinical value, as there were no treatment options. As novel, life-saving therapeutics evolve for the treatment of amyloidosis, routine THA specimens represent an opportunity for early identification of patients who would benefit from these therapies. Further study is warranted to develop a clinical pathway from orthopedic tissue diagnosis to treatment of amyloidosis.