Background: Medial meniscus posterior root tears (MMPRTs) cause pain and dysfunction and are associated with poor clinical outcomes with nonoperative management at short-term follow-up. However, little is known about the long-term natural history of these tears.
Purpose: The purpose of this study was to (1) provide an update to a previous minimum 2-year study on the natural progression of these tears and (2) evaluate long-term patient-reported and radiographic outcomes.
Study design: Case series (prognosis); Level of evidence, 4.
Methods: A retrospective review was performed on a cohort of patients with untreated MMPRTs, diagnosed between 2005 and 2013, who were followed clinically using International Knee Documentation Committee (IKDC), visual analog scale for pain, and Tegner activity scores as well as radiographically at a minimum 10-year follow-up. Failure was defined as conversion to arthroplasty or a severely abnormal subjective IKDC score <75.4.
Results: Overall, 5 (10%) of the original 52 patients with minimum 2-year outcomes were subsequently lost to follow-up. The remaining 47 patients (21 male, 26 female) were followed for a mean of 14 ± 2 years (range, 11-18 years). At final follow-up, 25 patients (53%) had progressed to total knee arthroplasty, 8 (17%) were deceased, and 14 (30%) had not progressed to total knee arthroplasty. The mean IKDC and Tegner activity scores for the 14 patients with remaining MMPRTs were 51.6 ± 22.2 and 3.1 ± 1.1, respectively, and the mean visual analog scale score was 4.4 ± 3.0. Radiographically, the mean Kellgren-Lawrence grade progressed from 1.2 ± 0.7 at baseline to 2.6 ± 0.5 at final follow-up (P < .001). At a minimum 10-year follow-up, 37 of 39 living patients (95%) had failed nonoperative treatment.
Conclusion: Poor clinical and radiographic outcomes were associated with the nonoperative treatment of degenerative MMPRTs at long-term follow-up. This study provides a valuable update on the natural history and long-term prognosis of nonoperatively treated MMPRTs.
Keywords: meniscal tear; meniscus extrusion; nonoperative; posterior horn.