Correlation of factors affecting correction of meniscalextrusion and outcome after medial meniscus root repair.

Abstract

Meniscus extrusion in medial meniscus posterior root tears (MMPRT) is a consistent MRI finding and correction of extrusion is a primary objective of the meniscal root repair. The purpose of the study is to evaluate feasibility of correction of extrusion and correlation of various factors affecting the postoperative extrusion correction and outcomes in all degenerative medial meniscus posterior roots (MMPRTs). A retrospective study of patientswho presented with degenerative MMPRTsfollowing trivial incident (Jun 2014 and Aug 2018) andincluded isolated Laprade type 2 root tear with extrusionin MRI. Patients with ligament injuries, tricompartmental arthritis, malalignment (> 50) and irreparable meniscal tears excluded. All patients underwent arthroscopic trans-tibial tunnel suture pull-out repair. A screening MRI was taken at a 6-month follow-up and functional scores (IKDC and Lysholm's) at final follow-up. The effects of age, gender, duration of symptoms, hip-knee-ankle angle on weight-bearing X-rays, ICRS grading of cartilage status, and MRI data (extrusion distance, tunnel location and healing status of meniscus) on outcomes were analysed. MMPRT (n = 54) with a mean follow-up of 34.6months (24-48). Mean functional outcomes improved postoperatively IKDC (43.40 ± 5.16-78.65 ± 5.11, p < 0.001) and Lysholm's (65.27 ± 4.28-83.16 ± 4.83, p < 0.001) scores at final follow-up. 57.4% (31) had good correction of extrusion, 3.7% (2) no correction and 38.8% (21) showed increase in extrusion postoperatively. Of all the factors we explored, age, ICRS (low grade)and knee varus(less 2.5 degree) affected extrusion correction. Patients with healed (41 patients), partially healed (9 patients)and anatomic tunnel placement (46 patients) had better extrusion correction than those with non-healing (4 patients) and non-anatomical tunnel (8patients). Patients younger than 50years, with low grade cartilage damage (ICRS 1, 2), lower KL grade and varus alignment (< 2.50) had good correction of extrusion. Correction of extrusion/progression of extrusion did not influence the clinical outcome at the short-term. The progression of meniscal extrusion is inevitable even after successful repair in elderly and high-risk patients. Retrospective Case series, level of evidence IV.