The clinical and radiographic outcomes of type 2 medial meniscus posterior root tears following transtibial pullout repair

Purpose The aim of this study was to compare the clinical outcomes of different subtypes of type 2 medial meniscus posterior root tears following transtibial pullout repair.
Methods In total, 147 patients (mean age: 66.2 +/- 8.3 years) who were diagnosed with type 2 medial meniscus posterior root tears and underwent transtibial pullout repair were included. Patients were divided into 2A (n = 31), 2B (n = 90), and 2C (n = 26) groups according to tear type. Clinical outcomes were assessed pre-operatively and at second-look arthroscopy using the Knee injury and Osteoarthritis Outcome Score. The meniscal healing status was evaluated at second-look arthroscopy. Medial meniscus extrusion was calculated using magnetic resonance imaging pre-operatively and at second-look arthroscopy.
Results No significant differences in pre-operative or post-operative clinical scores were observed between each subtype, although clinical scores improved post-operatively for each subtype. Significant differences were noted in the anteroposterior width of the bridging tissues at second-look arthroscopy (2A, 7.1 +/- 1.2; 2B, 6.2 +/- 1.7; and 2C, 6.2 +/- 1.7 mm; p = 0.045); type 2A tears were the widest. There was a significant difference in post-operative medial meniscus extrusion (2A, 3.2 +/- 0.9; 2B, 4.0 +/- 1.2; and 2C, 4.0 +/- 1.4 mm; p = 0.004) and its progression (2A, 0.7 +/- 0.6; 2B, 1.2 +/- 0.8; and 2C, 1.2 +/- 0.8 mm; p= 0.008), and type 2A tears were the shortest.
Conclusion Although there was no significant difference in the post-operative clinical scores among different type 2 tears in the short term, type 2A tears showed better healing and medial meniscus extrusion progression prevention, thus indicating the usefulness of classifying tear type in estimating post-operative outcomes.

This version of the article has been accepted for publication, after peer review (when applicable) and is subject to Springer Nature’s AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: http://dx.doi.org/10.1007/s00167-022-07293-9