Allograft Bone Dowel Incorporation to Tibial and Femoral Tunnels in Two-Stage Revision Anterior Cruciate Ligament Reconstruction.

Purpose The purpose of this study was to quantitatively evaluate the radiographic outcomes of allograft dowels used in two-stage revision ACLR and to compare the incorporation rates of dowels placed in tibial and femoral tunnels. Methods Prospective review of patients who underwent 2-stage revision-ACLR with allograft bone dowels. Inclusion criteria were tibial/femoral tunnel diameter of ≥14 mm on pre-operative computed tomography (CT) or overlapping of prior tunnels with planned tunnels. Second stage timing was determined based on qualitative dowel integration on CT obtained at ∼3 months after first stage. Quantitative analysis of incorporation rates was performed with the Union Ratio (UR) and Occupying Ratio (OR) on post-operative CT scans. Results 21 patients, aged 32.1 ± 11.4 (range, 18-50) years, were included. Second-stage procedures were performed at 6.5 ± 2.1 (range, 2.4 – 11.5) months after first-stage revision. All dowels showed no signs of degradation at the host bone/graft junction at the second-stage procedure. The average diameter of the dowels placed in tibial tunnels were greater than those placed in femoral tunnels (16.1 mm [SD, 2.3 mm] vs 12.4 mm [SD, 1.6 mm]; p = Conclusion Allograft bone dowels are a viable graft choice to replenish bone stock in the setting of a staged revision ACL reconstruction. Allograft dowels placed in femoral tunnels had a higher healing union ratio than tibial tunnel allografts and no evidence of degradation at bone/graft junction, with no difference seen in occupying ratio. Level of Evidence IV, case series