Bone Abstracts

Total hip arthroplasty (THA) is the treatment for severe hip osteoarthritis. It improves the quality of life, pain and patient autonomy. However, a periprosthetic resorption may occur, in 3–5% of patients after 10 years of the primary surgery requiring implant replacement. Bisphosphonates (BP), inhibitors of bone resorption, represent a potential candidate for modulating periprosthetic bone loss. Randomized controlled trials have also suggested that BP could prevent early periprosthetic bone loss after THA.

The aim of our study was to investigate the effect of a BP, risedronate on painful periprosthetic resorption in patients with THA, mainly on pain, radiographic bone loss, and periprosthetic density.

A monocentric, longitudinal, observational study, cohort type, included patients with painful aseptic loosening of their THA. All patients received Risedronate 75 mg, twice a month, during 2 years. Patients with mobility implant were excluded.

A 22 patients were included, mean age: 68 years. The mean period of first surgery of THA was 9.9 years. At the inclusion, the mean walking pain, measured with VAS, was 5.02. A statistically significant decrease of walking pain was observed 18 months after treatment (mean VAS: 2.5). The walking distance has increase significativelly by 1.25 km after 18 months. Concerning pain at rest, risédronate appears to provide non significativelly improvements During the study, eight patients required surgical replacement of their THA.

The analysis of X-rays showed a non significative decrease of periprosthetic bone resorption, predominant peripheral acetabular area, and in proximal femoral area, like increase periprosthetic density.

In this observational study, in patients with painful periprosthetic resorption of THA, risedronate seems to have an effect on pain, with a significant decrease of walking pain, and a significant increase of walking distance. Only 36% needed replacement of prosthetic implant. A randomized study will be conducted to confirm these results.