Double-bundle ACL and ALL reconstruction results in less femoral posterolateral bundle tunnel widening than outside-in double-bundle ACL reconstruction

Purpose To compare the clinical and radiological results of two double-bundle (DB) anterior cruciate ligament reconstruction (ACLR) techniques. DB ACLR and anterolateral ligament reconstruction (ALLR) with internal brace (IB), and outside-in (OI) DB ACLR. Hypothesis We hypothesized that DB ACLR and ALLR with IB wound yield less femoral tunnel, especially femoral posterolateral bundle tunnel complications, than OI DB ACLR without ALLR because of better rotational control. Both techniques could provide good postoperative clinical outcomes. Methods Patients who received DB ACLR and ALLR (ALLR group) and who received outside-in DB ACLR (non-ALLR group) were enrolled. Age, BMI, follow-up duration, meniscus repair, laterality, and knee range of motion (ROM) were collected. Lysholm, Tegner scale, and radiological results were compared. Results Thirty-four and 33 patients were enrolled in the ALLR and non-ALLR groups. Patient demographics were similar between groups. Both groups showed postoperative improvements in Lysholm (ALLR group, 62.5 ± 6.8 preoperatively and 85.1 ± 5.7 postoperatively ( p < 0.01); non-ALLR group, 63.5 ± 6.0 preoperatively and 82.9 ± 5.2 postoperatively ( p < 0.01)) and Tegner Scale (ALLR group, 4.97 ± 0.52 preoperatively and 7.79 ± 0.41 postoperatively ( p < 0.01); non-ALLR group, 4.91 ± 0.58 preoperatively and 7.7 ± 0.47 postoperatively ( p < 0.01)) at final follow-up. There were no significant differences between groups preoperatively (Lysholm, p = 0.324, Tegner, p = 0.649) and postoperatively (Lysholm, p = 0.679, Tegner, p = 0.369). The ALLR group exhibited significantly lower percentages of femoral posterolateral bundle tunnel widening ( p = 0.021) and a more femoral divergent angle ( p < 0.001) than the non-ALLR group. Furthermore, no femoral tunnel coalescence was observed in the ALLR group, while 3% of the non-ALLR group showed coalescence. Conclusions DB ACLR with ALLR yielded less femoral posterolateral bundle tunnel widening, no femoral tunnel coalescence, and more femoral divergent angle than OI DB ACLR. Both techniques provided good postoperative outcomes. Incorporating ALLR and IB may benefit patients undergoing DB ACLR. Level of evidence Level III, Retrospective comparative therapeutic trial. Clinical relevance DB ACLR with ALLR and IB provides less femoral PL tunnel widening, no femoral tunnel coalescence, and more divergent angles between the two femoral tunnels compared with traditional OI DB ACLR. DB ACLR with ALLR and IB technique provides more flexibility during femoral tunnel preparation.