Introduction

The most common meniscal lesion associated with anterior cruciate ligament (ACL) injury is tears of medial meniscus posterior horn (MMPH). As a treatment method, arthroscopic repair of longitudinal tear of MMPH has been reported a high rate of meniscal healing. However, there is a lack of literature that has focused on extent of longitudinal tear and clinical outcomes after arthroscopic repair. The purpose of this study, therefore, was to investigate the clinical outcomes and healing status for arthroscopic repair according to the tear length of medial meniscus.

Study Design: Level IIIb retrospective cohort study.

Methods

A total of 263 patients undergoing anterior cruciate ligament reconstruction between June 2011 and January 2021 were enrolled this study. Inclusion criteria were longitudinal tears of medial meniscus of the peripheral third (red-red zone) or the middle third (red-white zone) for which arthroscopic suture repair was performed with minimum 1 year-follow-up. Exclusion criteria were tears located in the central third of the medial meniscus (white-white zone) for which partial meniscectomy was performed only. Patients were assessed pre- and postoperatively with Tegner activity scale, Lysholm knee score, Hospital for Special Surgery knee (HSS) score. Healing status of the medial meniscal tears was evaluated on postoperative magnetic resonance imaging (MRI) scans or second-look arthroscopy. Additionally, according to the length of longitudinal tears, patients were classified into 2 groups: tears that located at the posterior compartment (Group 1); tears that extended to the midbody of the meniscus (Group 2). Clinical outcomes were compared between the two groups. The Arthroscopic suturing techniques performed vertically oriented suturing using a suture hook in both the modified all-inside and inside-out techniques according to tear extent.

Results

Eighty-three patients met the inclusion criteria. There were 73 (88%) men and 10 (12%) women with a mean age of 28 years (range, 14–56 years) at the time of surgery. The mean follow-up period was 24.7 months (range, 12–91 months). The average Lysholm knee score increased from 61.1±21 preoperatively to 90.4±9.7 at last follow-up (p<0.001). The average HSS score rose from 72.3±17.8 preoperatively to 91.1±7.5 at last follow-up (p<0.001). All patients underwent postoperative MRI scans, while second-look arthroscopy was performed for 41 patients (49.4%). The average period from surgery to postoperative MRI scans was 7.8 months, and second-look was 22.2 months. On the basis of postoperative MRI scans and second-look arthroscopic findings, 67 patients (80.7%), 10 patients (12.0%), 3 patients (3.6%), and 3 patients (3.6%) were categorized as complete healed, partial healed, failed, and additional tears, respectively. However, there was no significant difference in clinical outcomes and healing status between groups 1 (n = 52) and 2 (n = 31) classified according to the tear length. Three patients (3.6%) had failure of the meniscal repair and 3 patients (3.6%) had additional tear located more anteriorly to the initial tear.

Conclusion

Arthroscopic repair of longitudinal tear of medial meniscus posterior horn during ACL reconstruction yielded satisfactory clinical and radiographic outcomes, even if tear is extended to midbody of the medial meniscus. There was no significant difference in clinical outcomes and meniscus healing rates between groups classified according to the tear extent.