Amyloid deposition in osteoarthritis of the hip.

PURPOSE: The aim of this study was to examine the frequency of amyloid deposition in patients with end-stage hip osteoarthritis (OA). Further, their impact on the clinical situation and the OA severity were analyzed.
METHODS: Fifty patients with OA who consecutively underwent total hip replacement were prospectively evaluated. The X-rays of the patients were analyzed using a radiological score (Kellgren-Lawrence) to quantify the amount of radiological changes. A clinical score [Harris hip score (HHS)] was preoperatively calculated for every patient. Specimens from the femoral head of bone and cartilage, and additionally 1 cm(2) of the capsule, were obtained from every patient intraoperatively for analyzing the amyloid deposition histologically. A histological grading was also performed. On a subset of patients with amyloid deposits, the subtypes were characterized immunohistologically.
RESULTS: The only subtype of amyloid was ATTR. There was a high, significant correlation between articular amyloid deposition and the age of the patient at the time of the operation. No correlation was found for any other measured item, such as signs of inflammation in the blood samples, histological grading, radiological score or clinical score.
CONCLUSIONS: The frequency of amyloid deposits in the joint increases with age, and it can generally be considered to be of no pathologic significance, since a correlation with the radiological and histological changes was ruled out by our study. Thus, the presence of ATTR amyloid may simply be an incidental finding in aged joints.