Abstract
Objectives
To compare anatomic versus non-anatomic-posterolateral-corner (PLC) reconstructions with autografts for grade 3 posterolateral corner knee lesions combined with single bundle posterior cruciate ligament (PCL) reconstruction.
Methods
An outcome comparative study of chronic PCL lesions submitted to single bundle PCL reconstruction combined with a grade 3 PLC injury from Hughston and Fanelli classifications treated either by anatomic or non-anatomic PLC-reconstruction with autografts with at least 24 months of follow-up. Outcomes: Lysholm, IKDC, Tegner, side-to-side-difference (SSD) from posterior and varus stress radiographs, IKDC objective scores for posterior drawer, varus stress, dial test and recurvatum. Student’s t- and two-proportion Z-test were used. Power for sample size was 88.2%.
Results
Thirty-nine patients were evaluated: 18 in the Anatomic-PLC-group and 21 in the Non-anatomic-PLC-group. Mean follow-up: 28.3 months (range 24 to 59 months). Preoperatively, no significant differences were observed between the two groups in terms of age; time from injury until surgery; Lysholm; subjective IKDC; posterior, varus, external rotation or recurvatum laxity; stress radiographs; incidence of associated ligament and meniscus injuries. Postoperatively, no significant differences were observed for Lysholm (p=0.189), subjective IKDC (p=0.261), Tegner (p=0.385), mean improvement in Lysholm and IKDC scores (p=0.144, p=0.354, respectively), posterior tibial translation on stress radiographs [postoperative SSD (p=0.205) and percentage of patients with unacceptable (≥8mm) asymmetry (p=0.912)]; and complications. Significant differences favoring Anatomic-PLC-group were observed for Posterior-Drawer-Test (0.83±0.51 vs 1.1±0.43,p=0.046); Varus-Stress-Gapping at 30o (0.5±0.78 vs 1.14±0.85, p=0.01); Tibial-External-Rotation both 30o (33.3% vs 80.9%, p=0.002) and 90o (16.6% vs 47.6%, p=0.041); Asymmetrical-Recurvatum (5.5% vs 47.6%, p=0.00362); SSD-Lateral-Gapping-Varus-Stress-Radiographs (1.8±2.1 vs 3.35±2.28, p=0.028). Failure (presence of any of the following: Posterior Drawer ≥ 2+, Varus Stress ≥ 2+, SSD ≥ 8mm on Posterior-Radiograph or ≥ 4mm on Varus-Stress-Radiograph): 5% Anatomic versus 19% Non-anatomic, no statistical difference, p=0.103.
Conclusion
Anatomic posterolateral corner reconstruction with autografts provided superior stability compared to non-anatomic reconstruction in the setting of combined grade 3 posterolateral corner injuries and single bundle posterior cruciate ligament reconstruction.