Static tibiofemoral rotation remains stable after ACL reconstruction and is associated with posterior tibial slope in professional soccer players

PURPOSE: To evaluate whether static axial tibiofemoral (TF) rotational alignment, measured by the TF rotation angle and tibial tubercle-trochlear groove (TTTG) distance, is associated with posterior tibial slope (PTS) and changes over time following anterior cruciate ligament (ACL) reconstruction in professional soccer players, and whether these parameters are influenced by lateral extra-articular tenodesis (LET). METHODS: A retrospective review was conducted of professional soccer players who underwent primary ACL reconstruction between 2012 and 2024 and had preoperative and at least two postoperative magnetic resonance imaging (MRI) examinations. Players were excluded if they had previous ACL injury. Medial and lateral PTS, delta PTS (lateral-medial PTS), TTTG, static axial TF rotation and knee flexion were independently measured by two musculoskeletal radiologists, and multivariable regression and generalized linear mixed-effects models were used to assess the effects of PTS, time and LET on axial TF rotation and TTTG. RESULTS: Fifty-six professional soccer players (mean age 23.1 ± 4.4 years) were included, of whom 41 (73.2%) underwent concomitant LET. Postoperative MRIs were performed between 1 and 110 months postoperatively. Preoperative TTTG distance and axial TF rotation were 8.7 ± 3.3 mm and 6.7 ± 5.7°, respectively. In both ACL-deficient and reconstructed knees, greater medial PTS was significantly associated with less static internal axial TF rotation (B = -1.28 and -0.99, respectively; both p < 0.001), while greater lateral (B = 0.70 and 0.73; p = 0.017 and p = 0.004) and delta PTS (B = 0.97 and B = 0.85; p < 0.001) were associated with increased static internal axial TF rotation. LET had no significant effect on static TF rotation or TTTG distance over time (p > 0.05), and both variables remained stable longitudinally, independent of PTS. CONCLUSION: In professional soccer players undergoing ACL reconstruction, static axial TF rotation is associated with the medial, lateral and delta PTS but remains stable over time and is unaffected by LET. These findings support the role of bony anatomy as the primary driver of static rotational alignment, and counter the notion that the LET causes 'overconstraint' from a consequent fixed deformity. LEVEL OF EVIDENCE: Level III, retrospective case-control study.