Summary

Gold-standard inside-out meniscus repair technique results in overall 10% failure for lateral and 15% for medial meniscus. This finding, in addition to regaining closely preinjury activity levels and landing kinematics in the majority of the patients support the concept "Save the meniscus".

Abstract

Objective

To identify prognostic factors and improve decision-making for meniscus repair.

Methods

During a decade (2013-2022), a gold-standard inside-out meniscus suture technique with posteromedial and posterolateral protective windows was adopted for all meniscus tears involving the peripheral half-width and requiring 3 or more sutures (i.e. tear length > 10mm). Short tears requiring 1-2 sutures and repair of radial tears were excluded from this analysis. Data collected included patient and injury characteristics and intraoperative findings and procedures. Outcomes at minimum 2 year follow-up included activity level scores, IKDC-subjective, KOOS, and knee motion and laxity. In men with healthy contralateral limb, motion-analysis laboratory setup was used to measure hopping, drop jump kinematics, and knee muscle torque.

Results

Between 2013 and 2020, 81 menisci (59 medial and 22 lateral) in 79 patients (69 male and 12 female) underwent inside-out repair using 3-13 sutures, of which 34 had concomitant ACL reconstruction (ACLR). Seven patients (7 menisci repair, 2 lateral and 5 medial) were not available for follow-up examination. Delay injury-surgery ranged 2 weeks - 36 months. Age at operation ranged 14 - 55 years. Follow-up was 2 - 8 years. Ten patients (10 menisci) of which 8 were medial and 2 lateral underwent re-arthroscopy for resection of the repaired fragment (accounting for 15% of the medial and 10% of the lateral menisci repaired), and these cases did not differ in patient age or tear chronicity compared to patients who did not undergo repeated arthroscopy for meniscus resection. In cases of concomitant ACLR, failure of the meniscus repair was dramatically lower compared to isolated meniscus repair (3% vs. 27%, p=0.03). Smoking and articular cartilage lesions (Grade II-III) did not affect the repair. At follow-up, Tegner was median 6 (range 4-10) compared to 7 (range 5-10) at preinjury. IKDC-subjective was 92±7 and slightly lower in females than males (88±9 vs. 93±6, p=0.05). KOOS-ADL, KOOS-Pain, and KOOS-Sports were inversely associated with chronicity of the tear (r=-0.3, p=0.05) but not with number of sutures. Motion analysis showed closely symmetric landing kinematics and knee muscle torques.
*Comment: Minimum 2 year follow-up in this study will eventually evaluate over a hundred patients and menisci operated between 2013 and 2022.

Conclusions

Gold-standard inside-out meniscus repair technique results in overall 10% re-arthroscopy to meniscectomize unhealed repaired fragment for lateral and 15% for medial meniscus. Lower failure rates are observed in concomitant ACLR, while isolated long meniscus repair can result in over 20% failure rates, particularly for medial meniscus. These findings in addition to regaining closely preinjury activity levels, functional scores, and objective landing kinematics after this operation in the majority of the patients can justify the concept "Save the meniscus", and this principle is applicable also to populations over 40 and 50 years of age when handling long peripheral meniscus tears with repairable meniscus tissue of good quality, particularly with concomitant ACLR. Regression analyses or machine-learning algorithms at the completion of this study may enable elaborating patient-specific decision-making protocol which can be presented not only to recreational but also to professional athletes where "Time is money" concept should as well be accounted for.