Does intermeniscal ligament tenodesis affect meniscal allograft extrusion? Retrospective comparative study at a minimum follow-up of 2 years.

INTRODUCTION Meniscal allograft transplantation (MAT) is indicated for the treatment of post-meniscectomy syndrome in young patients who do not have severe cartilage loss. While its clinical effectiveness is well established in the short- and mid-term, it does not appear to stop the progression of osteoarthritis. Meniscal extrusion often occurs early on and is irreversible. The aim of this study was to evaluate results of arthroscopic MAT combined with reconstruction of the intermeniscal ligament (IML). HYPOTHESIS Concurrent reconstruction of the IML decreases the incidence of early allograft extrusion when compared to conventional soft-tissue techniques. MATERIALS AND METHODS This was a retrospective single-centre comparative study of 55 patients operated between 2011 and 2018. The 34 patients who met the inclusion criteria were divided into two subgroups: the IML group (MAT with IML repair, n=14) and the non-IML group (MAT without IML repair, n=20). Clinical outcomes consisted of the KOOS at the last follow-up visit and the surgical revision rate. MRI was performed at a minimum of 12 months (mean 34±25 months) to determine absolute and relative meniscal extrusion, sagittal anterior and posterior extrusion, and cartilage coverage in the frontal and sagittal planes. RESULTS The KOOS score was not significantly different between the two groups. There were no reoperations in the IML group, but there were four in the non-IML group (13%) (p=0.13). Meniscal extrusion of the allograft occurred in 43% of patients (6/14) in the IML group versus 85% (17/20) in the non-IML group (p<0.03). Absolute meniscal extrusion was 2.9mm ([2.2-3.6] SD=1.2) in the ILM group versus 5.4 mm ([4.1-6.7] SD=2.9) (p=0.004) in the non-ILM group. DISCUSSION Adding ILM tenodesis or reconstruction can significantly limit early extrusion of the meniscal allograft. Clinical outcomes at a mean of 34 months are not different when compared to standard procedure. These patients should be re-evaluated in the long term to determine whether the incidence of osteoarthritis is lower with ILM tenodesis. LEVEL OF EVIDENCE III; case-control study.