# Autogenous bone graft collection by acetabular reamers at the ilium yielded comparable volume with less blood loss and lower costs compared to the Reamer–Irrigator–Aspirator 2 system at the femur

## TL;DR

Using acetabular reamers at the ilium for bone graft collection resulted in similar graft volumes but less blood loss and lower costs compared to using the RIA2 system at the femur.

## Contribution

Demonstrates that ilium-based graft collection with acetabular reamers is a cost-effective and less blood-loss-intensive alternative to femur-based RIA2 graft collection.

## Key findings

- Mean graft volumes were similar between ARI and RIA2 (38.3 cc vs. 36.4 cc).
- ARI was associated with significantly lower blood loss, hemoglobin, and hematocrit changes compared to RIA2.
- ARI had lower equipment and sterilization costs compared to RIA2.

## Abstract

To compare autogenous bone graft volume, blood loss, transfusion rate, complications, and costs by collection using acetabular reamers at the ilium (ARI) to Reamer–Irrigator–Aspirator (RIA2) at the femur.

Adults who underwent long bone or sacral nonunion repair with autogenous bone graft collection by either unilateral ARI or RIA2 from femur from November 2020 to May 2023 at two academic trauma referral centers were retrospectively identified. Outcomes included graft volume, estimated blood less (EBL), perioperative change in hematocrit (ΔHct) and hemoglobin (ΔHgb), red blood cells (pRBC) units transfused intra- or postoperatively, infection, iatrogenic fracture, pathologic fracture, venous thromboembolism, and equipment costs per procedure.

Twenty-nine patients were included, of whom 18 received ARI was and 11 received RIA2. No differences were observed between groups regarding age, sex, body mass index, substance use, or medical comorbidities. Mean graft volumes were similar: ARI 38.3 cc (range 20–80 cc) versus RIA2 36.4 cc (range 10–60 cc), p = 0.74). ARI was associated with lower mean EBL (408.7 ± 210.0 cc vs. 750.0 ± 508.0 cc, p = 0.02), mean ΔHgb (2.1 ± 1.4 g/dL vs. 4.0 ± 1.7 g/dL, p = 0.007) and mean ΔHct (6.9 ± 4.9% vs. 11.9 ± 5.7%, p = 0.03). No differences in the incidence of pRBC transfusions (0.28 ± 0.67 vs. 0.64 ± 1.03 units, p = 0.32) or complications at the harvest site (5.6% vs. 0%, p = 1.00) were observed. ARI durable components acquisition ($11,500 vs. $12,500) and per case sterilization and disposable ($18 vs. $3,500) costs were lower.

Unilateral autogenous bone graft collection from ilium with acetabular reamers yielded similar graft volume with less blood loss at lower cost than RIA2 collection from femur.

The online version contains supplementary material available at 10.1007/s00590-025-04347-9.