The Effect of Tibial Tunnel Drilling Technique on Retained Intra-Articular Bone Debris Following Anterior Cruciate Ligament Reconstruction.

Purpose: To assess the effect of tibial tunnel drilling technique (retro-drilled bone socket vs full tibial tunnel) on the presence and grade of postoperative, intra-articular bone debris following primary hamstring anterior cruciate ligament (ACL) reconstruction.
Methods: This was a retrospective cohort study of primary hamstring autograft ACL reconstructions performed by 2 surgeons. Two blinded independent reviewers assessed the presence and length of retained intra-articular bone debris on the immediate postoperative lateral radiograph. Debris was graded according to a predefined 5-point ordinal grading system: grade 0 (no debris) to IV (severe debris). Results were analyzed according to the type of tibial tunnel; retro-drilled socket or full tibial tunnel using Kappa statistics and the Mann-Whitney U test.
Results: Sixty-five patients undergoing primary hamstring ACL were included (39 tibial socket: 26 full tibial tunnel). Bone debris was observed among the tibial socket technique in 29 of 39 instances (74.3%), compared with 14 of 26 (53.8%) instances for the full tibial tunnel technique ( P  = .09). Where there was measurable debris present, the tibial socket group had a mean length of bone debris of 13.7 ± 6.2 mm as compared with the full tibial tunnel, 10.0 ± 4.7 mm ( P  = .165). There were significant differences in bone debris gradings between the 2 treatment groups, with tibial sockets having an overall greater grade ( P  = .04).
Conclusions: A difference in the presence of, or length of, retained bone debris on the postoperative lateral radiograph was not demonstrated between the retro-drilled bone socket and full tibial tunnel techniques. However, when bone debris was present, greater grades of debris were seen in the retro-drilled socket group.
Level of Evidence: III, retrospective, comparative study.
(© 2023 The Authors.)