Estimating Patient Eligibility And Benefit Of Intravenous Zolendronic Acid In Hip Fracture Patients: A Service Evaluation

Abstract

Background Low trauma hip fractures are serious and carry an estimated re-fracture rate of 10.6%, leading increased morbidity, mortality and healthcare cost. Intravenous Zolendronic Acid (IVZ) administration following hip fracture reduces re-fracture risk by approximately 23% and is recommended yearly for three years by National Osteoporosis Guidelines Group (NOGG) 2021. However, a significant treatment gap remains with only one-fifth of patients receiving IVZ pre-discharge, due to implementation challenges, such as suboptimal Vitamin D levels and lack of resources for yearly infusions. Recently published consensus guidelines offer practical advice as to how to overcome these barriers. This service evaluation estimates the proportion of hip fracture patients eligible for IVZ; as well as the re-fracture rate, prior to the introduction of a local IVZ pathway. Methods Approval from local Quality and Patient Safety Department was received. Low trauma hip fracture patients were identified from the local Orthogeriatric database (October 2019 to January 2021). Hospital electronic laboratory and radiology software were used to identify renal function on discharge and evidence of further fractures (at six months, 1 year and 3 years). Subjects were deemed potentially eligible for IVZ if they had an estimated glomerular filtration rate (eGFR) of ≥50 mls/min (a proxy for calculated creatinine clearance ≥30mls/min in this patient cohort). Results Of 463 subjects, 384 (82.9%) had an eGFR ≥50. Re-fracture data was collected for 263 eligible subjects. Seventeen (6.5%) re-fractured within six months, 21 (8%) re-fractured within a year and 45 (17.1%) re-fractured at any stage post discharge. Conclusion IVZ treatment is the most efficacious secondary fracture prevention post-hip fracture, and most patients are eligible for this treatment. Implementing IVZ pathways for hip fracture patients may significantly reduce re-fracture rate, however expansion of resources allocated to Orthogeriatrics and Fracture Liaison teams is required to successfully implement inpatient pathways and ongoing care.