Acute rather than insidious symptom onset is associated with better postoperative outcomes after transtibial pull-out repair for medial meniscus posterior root tears.

Purpose: To compare clinical and radiologic outcomes after transtibial pull-out repair for medial meniscus posterior root tears (MMPRTs) between patients with acute and insidious symptom onset. Methods: Patients who underwent transtibial pull-out repair for MMPRTs between March 2022 and December 2023 and had a minimum 2-year follow-up were retrospectively reviewed. Patients were classified into an acute-onset group, defined by abrupt symptom onset during or immediately after a clear inciting knee incident, or an insidious-onset group, defined by gradually progressive symptoms without a definite precipitating event. Outcomes included patient-reported outcome measures (PROMs) and radiologic parameters. PROMs comprised the International Knee Documentation Committee (IKDC) and Lysholm scores, with minimal clinically important difference (MCID) achievement also assessed. Radiologic outcomes included Kellgren-Lawrence (KL) grade progression, meniscal extrusion and magnetic resonance imaging (MRI) healing status. Results: A total of 49 patients were included (28 acute-onset, 21 insidious-onset). Both groups showed significant improvement in IKDC and Lysholm scores, with similar MCID achievement rates. At final follow-up, the Acute Group had higher median IKDC scores than the Insidious Group (73.0 [66.8-79.0] vs. 67.0 [62.0-69.0]; Conclusion: Acute-onset MMPRTs were associated with better postoperative functional outcomes and less radiologic progression than insidious-onset MMPRTs, although the clinical relevance of the small difference in meniscal extrusion remains uncertain. Therefore, symptom-onset pattern may provide potentially useful information for preoperative prognostic counselling, but this association should be interpreted cautiously and confirmed in prospective studies. Level of Evidence: Level III.