Effects of teriparatide on fusion rates in patients undergoing complex foot and ankle arthrodesis

Background: Here, we determined whether teriparatide treatment would increase fusion rates after foot and ankle arthrodesis by comparing treatment results between patients with high-risk factors for nonunion who received teriparatide against those who did not. Methods: We retrospectively reviewed 66 consecutive patients who underwent foot and ankle arthrodesis. The inclusion criterion was the presence of at least one of the following risk factors for nonunion after previous foot and ankle arthrodesis: deformity, bone defects, avascular necrosis, and nonunion. Sixteen patients were finally enrolled and divided into 2 groups: 8 patients received teriparatide treatment after fusion surgery (PTH group), and 8 patients did not (control group). Results: The fusion rate was significantly greater in the PTH group than in the control group (100% vs 50%). Four patients in the control group developed nonunion, 3 of whom underwent revision fusion; however, all patients received the teriparatide treatment after revision surgery and subsequently achieved union. No significant differences in demographics, fusion sites, and complication rates were found. Conclusion: Though the sample size was small, the current study suggests that teriparatide administration may improve fusion rates in patients with high-risk factors for nonunion after foot and ankle arthrodesis.