Arthroscopic repair of horizontal cleavage meniscus tears provides good clinical outcomes in spite of poor meniscus healing

Purpose The purpose of this study was to evaluate the clinical outcomes and meniscus healing after arthroscopic repair of horizontal-cleavage meniscus tears, compared with vertical-longitudinal meniscus tears. Methods This was a retrospective review of a consecutive series of 52 meniscal repairs for horizontal-cleavage tears (n = 27) or vertical-longitudinal tears (n = 25); the groups were compared with respect to clinical symptoms and meniscal healing. Arthroscopic meniscal repair was performed using the inside-out technique with a marrow-stimulating technique. Clinical symptoms were evaluated using the Lysholm score and Knee injury and osteoarthritis outcome score (KOOS). Meniscus healing was evaluated by MRI. Results The mean follow-up periods were 35.4 +/- 8.9 months in the horizontal-cleavage tear group and 39.8 +/- 8.3 months in the vertical-longitudinal tear group. There were no significant differences in Lysholm score and KOOS, including each subscale, between the horizontal-cleavage tear- and vertical-longitudinal tear-groups at the final follow-up. At the final follow-up, MRI meniscus grades 0 and 1 were significantly more frequent in the vertical-longitudinal tear-group than in the horizontal-cleavage tear-group, while grade 3 was significantly more frequent in the horizontal-cleavage tear group than in the vertical-longitudinal tear group (p < 0.0001). Conclusions Although meniscus healing of horizontal-cleavage tears may be poor, arthroscopic repair should be considered for horizontal-cleavage tears because it does provide good clinical outcomes.