Perioperative teriparatide for preventing proximal junctional kyphosis and failure in patients with osteoporosis after adult thoracolumbar spinal deformity surgery: a prospective randomized controlled trial

We conducted a randomized controlled trial to assess the preventive effect of perioperative teriparatide on proximal junctional kyphosis and proximal junctional failure (PJF) in osteoporosis patients undergoing adult spinal deformity surgery. Teriparatide (experimental group) and denosumab (active control) were administered. The teriparatide group demonstrated significantly better PJF incidence and VAS for back pain, EQ-5D than the control group. Purpose This randomized controlled trial is aimed at investigating and comparing the effects of perioperative teriparatide and denosumab as an active control for preventing proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) in patients with osteoporosis after adult spinal deformity (ASD) surgery. Methods A total of 64 patients with osteoporosis, who planned to undergo ASD surgery, were randomly assigned to the teriparatide and denosumab groups. Treatment with teriparatide or denosumab in both groups was conducted from 3 months preoperatively to 3 months postoperatively based on the standard regimen for each medication. The primary outcome was PJK and PJF incidence within 1 year after ASD surgery. The secondary outcomes were patient-reported outcomes (PROs), bone mineral density (BMD), and dual-energy X-ray absorptiometry (DEXA) t-score of the hip. Results The teriparatide group showed a lower incidence of PJK than the denosumab group (17.2% vs. 33.3%), although this difference was not statistically significant (p = 0.165 in a modified intention-to-treat (mITT) analysis). Furthermore, the teriparatide group exhibited a significantly lower incidence of PJF than the denosumab group (3.4% vs. 22.2%; p = 0.034 in the mITT analysis). As for the secondary outcomes, no significant differences in BMD of the hip were observed between the two groups at the 1-year follow-up. The teriparatide group showed significantly improved postoperative VAS for back pain and EQ-5D score. Conclusions Perioperative teriparatide treatment of patients with osteoporosis after ASD surgery effectively reduced PJF incidence and postoperative back pain.