Intravenous bisphosphonate therapy does not delay fracture healing in inter-trochanteric femur fractures – A randomised controlled study

Abstract

Hip fractures in elderly are commonly associated with osteoporosis and surgical outcome is influenced by its concurrent management. The purpose of our study is to determine the association between timing of bisphosphonate administration in inter-trochanteric (IT) fractures and fracture healing. Patients with IT fractures (aged≥50 years) and T-score ≤ -1.5 [WHO defines osteopenia as T-score between −1 and −2.5, and osteoporosis as T-score ≤ -2.5 on DEXA scan (which was obtained post-operatively in our cohort)], who underwent proximal femoral nailing were included. Patients were divided into three groups: group 1a-intravenous bisphosphonate {ivBP [zoledronic acid (ZA)]} given within one week, group 1b-ZA at six weeks and group 2-control group. Post-operative radiographs were assessed for reduction parameters [neck-shaft angle, tip-apex distance, reduction variance]. Radiological union was determined using RUSH score and functional outcome (at one year) with Modified Harris Hip Scores. 41 (23 males), 40 (15 males) and 42 (15 males) patients were included in groups 1a, 1b and 2, respectively (no statistical difference in sex distribution among the groups; p = 0.12). Mean age in groups 1a, 1b and 2 was 71.8 ± 8.1, 75.9 ± 8.5 and 72.3 ± 10.6 years (p = 0.09). There was no significant difference in the pattern of injuries (AO classification) among the groups (p = 0.72). Mean time to union in groups 1a, 1b and 2 was 13.7,13.7 and 14.2 weeks, respectively (p = 0.69). Mean time to union in AO types A1, A2 and A3 fractures was 13.2 ± 2.1, 13.7 ± 2.8 and 16.1 ± 4.9 weeks (p = 0.01). We did not observe any association between T-scores and fracture union (hip:p = 0.52, spine:p = 0.93).The functional outcome was similar among groups (p = 0.96). Early administration of ZA did not negatively influence fracture healing in patients undergoing fixation of IT fractures. Among the various other factors analyzed, there was a statistically significant association between the fracture type (AO type A3) and longer time to fracture union.