Safety of in Hospital Parenteral Anti Osteoporosis Therapy Following Hip Fracture: A Retrospective Cohort

Background:
Parenteral treatment with zoledronic acid (ZA) or denosumab (DB) is considered first line treatment following hip fracture. Fever, hypocalcemia and renal injury have been described following these treatments.

Aim:
To assess rates of adverse events (AE) following in-hospital treatment with ZA and DB.

Methods:
This retrospective study included patients over age 65 admitted for rehabilitation to the geriatrics department following surgery for hip fracture, who were treated by the Soroka Fracture Liaison Service between 7/2014 and 1/2020, and received in-hospital treatment with ZA or DB. Demographic, clinical and biochemical data were collected from the electronic medical records. Albumin corrected serum calcium less than 8.5 and creatinine increase of 0.5 mg/dl or more during 30 days following treatment were considered as AE. Body temperature before and after treatment was documented.

Results:
362 patients met inclusion and exclusion criteria; 134 and 228 were treated with DB and ZA respectively. Mean change in body temperature after ZA was significant (P<0.001) but below 38 and unchanged after DB, Rates of hypocalcemia were 18% and 29.1% in the ZA and DB groups respectively (p=0.009). Rates of worsening renal function were 3.9% and 4.5% in the ZA and DB groups respectively (p=0.8). In multivariable analysis pretreatment calcium was found to be associated with post treatment hypocalcemia (OR 0.294 =P=0.004). Female gender was found to be protective from renal injury (OR for 0.25 P=0.02).

Conclusion:
In hospital parenteral treatment for osteoporosis was associated with low rates of worsening renal function but not uncommonly with hypocalcemia.