In the revision setting after primary anatomic DB ACLR, most of cases can be dealt with one-stage revision using pre-existing tunnels, and the objective laxity and clinical scores after revision ACLR were comparable to those after primary ACLR, except Tegner score.
Tunnel widening after anterior cruciate ligament reconstruction (ACLR) makes revision surgery more difficult, particularly in patients who underwent primary reconstruction with double-bundle (DB) technique. Amount of tunnel widening and corresponding surgical techniques in revision setting after primary DB ACLR is underreported, and outcomes of revision ACLR after primary DB ACLR has not been reported. The purpose of current study is to report the degree of tunnel widening at the time of revision ACLR, the methods of revision ACLR, and outcomes of revision ACLR in patients who received primary ACLR with anatomic 4-tunnel DB technique.
A total of 493 knees who underwent primary anatomic 4-tunnel DB ACLR from April 2010 to July 2016 were retrospectively reviewed and 40 knees who received revision ACLR were enrolled in the study. The cross-sectional area (CSA) of each tunnel at aperture and 1 cm from aperture was measured on computed tomography (CT) images which were taken on perioperative period of revision surgery, and was compared to the CSA measured on CT taken immediately after primary ACLR. The surgical methods were also reviewed with medical records and arthroscopic photos. For clinical assessment, range of motion (ROM), objective laxity using KT-2000 (MEDmetric, San Diego, CA), Lysholm score, Hospital for Special Surgery (HSS) score, International Knee Documentation Committee (IKDC) subjective score, Tegner score after revision ACLR were compared to those after primary ACLR.
Mean interval between primary ACLR and revision ACLR was 24 months (range, 4–82 months). Mean tunnel widenings of anteromedial and posterolateral femur tunnels at apertures were 47.4% (range, -22.8–181.9%) and 52.3% (range, -24.3–179.7%), respectively. Those calculated at 1cm from apertures were 47.0% (range, -27.8–182.9%) and 56.1% (range, -55.6–260.8%), respectively. Mean tunnel widenings of anteromedial and posterolateral tibia tunnels at apertures were 42.4% (range, -19.6–192.9%) and 24.3% (range, -44.39–78.9%), respectively. Those calculated at 1cm from apertures were 70.9% (range, 3.4–201.2%) and 48.1% (range, -1.6–171.0%), respectively. Among 40 knees, 38 knees (95%) underwent one-stage revision surgery with DB technique utilizing pre-existing tunnels without compromised anatomic positioning of grafts. The other 2 knees (5%) underwent two-stage revision consisted of bone grafting followed by single bundle reconstruction due to overly expanded tunnel which prevented anatomic positioning of grafts. The post-revision ROM, objective laxity using KT-2000, Lysholm score, HSS score, IKDC subjective score did not show statistically significant difference from those after primary ACLR, but Tegner score after revision ACLR was inferior to that after primary ACLR by 1.3 point (P=0.012).
In the revision setting after primary anatomic DB ACLR, most of the cases could be dealt with one-stage revision with DB technique using pre-existing tunnels, and the objective laxity and clinical scores after revision DB ACLR were comparable to those after primary DB ACLR, except Tegner score.
Level of Evidence: Case series, Level IV