The impact of prior fragility fractures on long-term periprosthetic fracture risk following total knee arthroplasty

Summary The study found that patients undergoing total knee arthroplasty with prior fragility fracture had increased risk of subsequent fragility fracture and periprosthetic fracture within 8 years postoperatively when compared to those without a prior history. However, these patients were not at increased risk for all-cause revision within this period. Purpose The aim of this study was to characterize the association of prior FFs on long-term risk of secondary fragility fracture (FF), periprosthetic fracture (PPF), and revision TKA. Methods Patients at least 50 years of age who underwent elective TKA were identified in the PearlDiver Database. Patients were stratified based on whether they sustained a FF within 3 years prior to TKA (7410 patients) or not (712,954 patients). Demographics and comorbidities were collected. Kaplan Meier analysis was used to observe the cumulative incidence of all-cause revision, PPF, and secondary FF within 8 years of TKA. Cox Proportional hazard ratio analysis was used to statistically compare the risk. Results In total, 1.0% of patients had a FF within three years of TKA. Of these patients, only 22.6% and 10.9% had a coded diagnosis of osteoporosis and osteopenia, respectively, at time of TKA. The 8-year cumulative incidence of secondary FF and periprosthetic fracture was significantly higher in those with a prior FF (27.5% secondary FF and 1.9% PPF) when compared to those without (9.1% secondary FF and 0.7% PPF). After adjusting for covariates, patients with a recent FF had significantly higher risks of secondary FF (HR 2.73; p < 0.001) and periprosthetic fracture (HR 1.86; p < 0.001) than those without a recent FF. Conclusions Recent FF before TKA is associated with increased risk for additional FF and PPF within 8 years following TKA. Surgeons should ensure appropriate management of fragility fracture is undertaken prior to TKA to minimize fracture risk, and if not, be vigilant to identify patients with prior FF or other bone health risk factors who may have undocumented osteoporosis.