Effect of bisphosphonate initiation at week 2 versus week 12 on short-term functional recovery after femoral neck fracture: a randomized controlled trial

SUMMARY: The appropriate time to initiate bisphosphonate treatment after a fragility fracture has not yet been established. In this study, we found no significant differences in short-term functional recovery between femoral neck fracture patients who received bisphosphonate treatment at 2 versus 12 weeks after hemiarthroplasty. INTRODUCTION: Bisphosphonate is the mainstay therapy for prevention and treatment of osteoporosis. The aim of this study was to investigate the effect of bisphosphonate initiation on short-term functional recovery in femoral neck fracture patients at 2 versus 12 weeks after hemiarthroplasty. METHODS: One hundred patients were randomly allocated into two groups in a parallel group designed, randomized, controlled trial. Both groups received risedronate 35 mg/week at either 2 or 12 weeks after hemiarthroplasty. All patients received calcium and vitamin D supplementation. Functional recovery was assessed by de Morton Mobility Index, Barthel Index, EuroQol 5D, visual analog scale, 2-min walk test, and timed get-up-and-go test at 2 weeks, 3 months, and 1 year after surgery. RESULTS: At the 3-month follow-up, all functional outcome measures showed significant improvement in both groups. There were no statistically significant differences in any of the functional outcomes between groups at both the 3-month and 1-year follow-ups. Although patients who received bisphosphonate initiation at week 2 had lower serum calcium level at 3 months and more overall adverse events than patients in the week 12 group, no patients in either group discontinued their prescribed medications. CONCLUSIONS: While underpowered, the findings of this study suggest that there were no significant differences in short-term functional recovery or significant adverse events between the two bisphosphonate groups. Thus, the initiation of bisphosphonate therapy may be considered as early as 2 weeks after femoral neck fracture. It is important that low serum calcium and vitamin D status must be corrected with calcium and vitamin D supplementation prior to or at the time of bisphosphonate initiation. CLINICAL TRIAL REGISTRATION NUMBER: This study was registered in the database via the Protocol Registration and Results System (PRS) (NCT02148848). ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11657-017-0321-8) contains supplementary material, which is available to authorized users.