Background: Previous studies have reported various healing rates (0%-100%) as evaluated by second-look arthroscopy after repair of medial meniscal root tears (MMRTs). Such variable results might provoke suspicion of the necessity for repair. Furthermore, the effect of meniscal healing on the clinical outcomes has not been reported.
Purpose: To more precisely determine the healing rate of MMRTs repaired through the transseptal portal, which could provide objective visualization of the healed meniscus, and to identify the effect of meniscal healing on the clinical and radiological outcomes.
Study design: Case series; Level of evidence, 4.
Methods: Between June 2010 and April 2015, 56 patients underwent pullout suture for MMRT. Lysholm score, Hospital for Special Surgery score, International Knee Documentation Committee subjective score, medial joint space height, and Kellgren-Lawrence (K-L) grade were evaluated. Thirty-three patients underwent second-look arthroscopy and were divided into a "stable healed group" and "unhealed group" according to their healing status, as evaluated through the transseptal portal. The intraoperative, clinical, and radiological outcomes of the 2 groups were compared.
Results: All other clinical outcomes improved. However, medial joint space became significantly narrower ( P < .001), and 23 patients (41%) showed K-L grade progression. On the basis of second-look arthroscopy, 23 patients (69.7%) were classified into a stable healed group and 10 (30.3%) into a unhealed group. The stable healed group showed a higher Hospital for Special Surgery score ( P = .023), International Knee Documentation Committee subjective score ( P = .031), and successful microfracture rate ( P = .023), with less progression of medial joint space narrowing ( P < .001) and K-L grade ( P < .001).
Conclusion: Despite degenerative change progression, clinical outcomes were improved. The successful healing rate was 69.7% after repair of MMRTs. Compared with the unhealed group, the stable healed group showed better clinical outcomes and less degenerative change progression.
Keywords: knee; meniscus; posterior root tear; pullout suture; second-look examination.