Endocrine Abstracts

Calcium sulphate (CS) beads are increasingly used in orthopaedic procedures for the local delivery of antibiotics to prevent infections in the immediate post-operative period. CS beads are typically absorbed over six weeks, though there are a number of factors affecting the rate of absorption. Hypercalcemia in the days following orthopaedic surgery involving CS beads is rarely documented in the literature. A 77-year-old female was readmitted to Tallaght University Hospital from a rehabilitation site, five days after elective total hip replacement, for revision of total hip replacement. She was noted to have delirium and constipation. On readmission, corrected calcium was 4.04mmol/l (2.15 – 2.55mmol/l). Prior to the initial surgery her corrected calcium was 2.46mmo/l (2.15 – 2.55mmol/l). She had no previous history of hypercalcemia. Her renal function was stable with eGFR >90 ml/min/1.73m2. Concurrent vitamin D level was 62 nmol/l (>50 nmol/l suggests normal vitamin D status) and parathyroid hormone (PTH) level was 13 pg/mL (15-65pg/mL). CS beads had been used in her initial procedure. Given her age and PTH level, she also had a worked-up for possible occult malignancy, which was negative. The patient with given zolendronic acid and intravenous fluids. Treatment was complicated by pulmonary oedema requiring addition of furosemide. Nine days after admission, serum corrected calcium was within normal range and remained stable, with resolution of confusion. This case demonstrates the importance of checking calcium levels in confused patients post-orthopaedic procedures and considering CS beads as the cause in those patients who are hypercalcaemic.