Short-term results and surgical technique of arthroscopic centralization as an augmentation for medial meniscus extrusion caused by medial meniscus posterior root tear

IntroductionThe purpose of this study was to perform medial meniscus (MM) centralization for medial meniscus extrusion (MME) associated with medial meniscus posterior root tear (MMPRT) and to examine the short-term results. The hypothesis is that arthroscopic centralization as an augmentation of MMPRT repair improves clinical outcomes and the extrusion distance of MM in short-term results.Materials and methodsTwenty-six patients (mean age 62.16.0 years) who underwent arthroscopic centralization as an augmentation of MMPRT repair were included. Clinical evaluation was performed before and 2 years after surgery using Lysholm score and knee injury and osteoarthritis outcome score (KOOS). Image evaluation used MRI and plain X-ray images. The extrusion distance and MME ratio were compared on MRI images before and 2 years after surgery. The degree of osteoarthritis (OA) was evaluated using Kellgren-Lawrence classification. The degree of OA and hip-knee-ankle (HKA) angle were compared by plane X-ray images before and 2 years after surgery.ResultsIn clinical results, both Lysholm score and KOOS improved significantly after surgery. In image evaluation, the extrusion distance decreased significantly from 4.80.7 mm before surgery to 2.7 +/- 0.3 mm 2 years after surgery (p<0.05). The MME ratio was significantly improved from 40.2<plus/minus>7.0% before surgery to 22.6 +/- 3.6% after surgery (p<0.05). There was no significant difference in HKA angle at 2 years after surgery (p=0.13).ConclusionsThe arthroscopic centralization for medial meniscal extrusion associated with MMPRT significantly improved clinical outcomes and the extrusion distance of MM. It is also one of the surgical techniques that can suppress medial meniscus extrusion.Level of evidenceIV, therapeutic case series.