Is Lateral Posterior Tibial Slope Correlated With Clinical Outcomes of Lateral Meniscus Allograft Transplantation?

Purpose: To investigate (1) the correlation between lateral posterior tibial slope (PTS) and clinical outcomes of lateral meniscus allograft transplantation (MAT) and (2) the difference of lateral PTS between the extrusion and nonextrusion groups or between the failure and nonfailure groups in lateral MAT. Methods: Between January 2001 and February 2016, we retrospectively evaluated 61 patients (mean age, 29.1 +/- 12.2 years) who underwent postoperative magnetic resonance imaging (MRI) and were followed for a minimum of 2 years after primary lateral MAT. The lateral PTS and graft extrusion in the coronal and sagittal planes were assessed by using MRI performed at 1 year postoperatively. Clinical scores and graft failure were evaluated at the last follow-up visit. The correlation between lateral PTS and clinical outcomes (clinical scores, graft extrusion) was analyzed. Lateral PTS was compared between the extrusion and nonextrusion groups and between the failure and nonfailure groups. Results: Mean lateral PTS on MRI was 6.6 degrees +/- 3.1 degrees (range, 0.8 degrees to 15.7 degrees). A significant correlation was not identified between lateral PTS and clinical outcomes (clinical scores, graft extrusion in the coronal and sagittal planes). A significant difference in lateral PTS was not identified between the extrusion and nonextrusion groups in the coronal (6.2 degrees +/- 2.5 degrees vs 7.0 degrees +/- 3.4 degrees, P = .400) and sagittal (anterior horn, 6.5 degrees +/- 2.3 degrees vs 6.7 degrees +/- 3.7 degrees, P =.988; posterior horn, 6.8 degrees +/- 3.5 degrees vs 6.5 degrees +/- 2.7 degrees, P =.771) planes. Moreover, a significant difference was not identified between the failure and nonfailure groups (7.5 degrees +/- 3.3 degrees vs 6.4 degrees +/- 3.0 degrees, P =.388). Conclusions: A significant correlation between lateral PTS and clinical or radiologic outcomes of lateral MAT was not identified.