Perioperative Anabolic Osteoporosis Pharmacotherapy is Associated with Lower Rates of Proximal Junctional Kyphosis After Adult Spinal Deformity Surgery

Study Design: Systematic review and meta-analysis. Objective: To determine whether perioperative anabolic osteoporosis pharmacotherapy is associated with lower rates of (1) proximal junctional kyphosis (PJK) and (2) reoperation for mechanical failure following adult spinal deformity surgery. Summary of Background Data: Mechanical complications occur in 15 to 40 percent of patients following adult spinal deformity surgery. Although poor bone quality has been associated with mechanical failure, no quantitative synthesis has tested whether perioperative pharmacotherapy alters these outcomes. Methods: PubMed, Embase, Scopus, and Cochrane CENTRAL were searched through April 30, 2026 (PROSPERO CRD420261374961). Random-effects meta-analysis was performed for the primary and prespecified secondary outcomes. The primary pool comprised anabolic-exposed studies; a class-agnostic pool that additionally included a single antiresorptive-dominant, claims-based study was retained as a sensitivity analysis. Results: Thirteen studies (one randomized controlled trial, twelve observational; 2,247 patients) met inclusion criteria. Teriparatide was the primary or sole study agent in nine of thirteen studies. Anabolic pharmacotherapy was associated with reduced odds of PJK (pooled OR 0.51, 95% CI 0.30 to 0.86, P =0.012; I2=0%, k=5) and of reoperation for mechanical failure (OR 0.36, 95% CI 0.14 to 0.88, P =0.025; I2=55%, k=4). A broadened-class sensitivity analysis including the antiresorptive-dominant study was directionally consistent (OR 0.63, 95% CI 0.42 to 0.94, P =0.024). Leave-one-out sensitivity analysis preserved the direction of the PJK effect across all iterations. Conclusions: Perioperative anabolic osteoporosis pharmacotherapy is associated with lower rates of proximal junctional kyphosis and reoperation following adult spinal deformity surgery, providing the first pooled evidence that the underlying bone-quality substrate may be pharmacologically modifiable. The certainty of this evidence is low; these findings support incorporating bone health optimization into perioperative planning as a modifiable target and prioritizing randomized trials of specific agents. Level of Evidence: II Level of Evidence: II: Systematic review of cohort studies with one randomized controlled trial