Bone turnover markers in the early stage of rapidly progressive osteoarthritis of the hip

Abstract

Objective: Previous reports have demonstrated that patients with end-stage rapidly progressive osteoarthritis of the hip (RPOH) show significantly higher serum levels of bone turnover markers thanthose with osteoarthritis (OA). However, the characteristics of bone turnover markers in the early stageof RPOH remain unclear. This study aimed to elucidate the association of bone turnover markers withdisease progression in the early stage of RPOH.Methods: This study included 29 postmenopausal female patients with joint space narrowing >2 mmdemonstrated on a series of radiographs and computed tomography within 1 year following the onset of hip pain. The study also included 9 postmenopausal female patients with hip OA secondary todevelopmental dysplasia showing femoral head destruction. Cortical thickness index (CTI) associatedwith bone mineral density of the hip was analyzed. Serum concentrations of tartrate-resistant acidphosphatase-5b (TRACP-5b) and bone alkaline phosphatase (BAP) were evaluated.Results: RPOH was classified into two types on the basis of the absence (type 1, n=13) or presence(type 2, n=16) of subsequent destruction of the femoral head within 1 year following disease onset.TRACP-5b and BAP significantly increased in RPOH type 2 compared with type 1 and OA. Receiver operating characteristic curve analyses indicated that TRACP-5b and BAP could differentiate RPOH type2 from type 1 within 1 year following the onset. CTI showed no difference among the RPOH types 1and 2 and OA.Conclusion: High serum levels of bone turnover markers may be associated with destruction of thefemoral head in the early stage of RPOH.