Effect of Additional Centralization Procedure on Intraoperative Ultrasound-Assessed Medial Meniscal Extrusion Compared With Medial Meniscal Posterior Root Repair Alone

Abstract

Background:

Medial meniscal extrusion (MME) contributes to knee osteoarthritis and is often caused by a medial meniscal posterior root tear (MMPRT). Although early surgical repair of MMPRT improves outcomes, MME often persists. Centralization techniques aim to reduce meniscal extrusion by anchoring the capsule to the tibial plateau; however, their clinical effectiveness when combined with MMPRT repair remains uncertain.

Purpose:

To evaluate the efficacy of centralization combined with MMPRT repair in reducing MME using intraoperative ultrasound.

Study Design:

Case series; Level of evidence, 4.

Methods:

The study included 26 patients who underwent MMPRT repair with a pullout technique and centralization with three knotless anchors. Of these, 22 patients also underwent additional high tibial osteotomy. Initial tensions of 0 to 40 N were applied to the pullout repair sutures at 60° of knee flexion, and MME was measured by intraoperative ultrasound. MME was also measured at 0°, 30°, 60°, 90°, and 120° of knee flexion, as well as at internally and externally rotated positions (IR and ER) at 30° and 90° of knee flexion, before MMPRT repair, after repair, and after centralization. A total of 22 patients underwent additional high tibial osteotomy after MMPRT repair and centralization.

Results:

When tension of 0 to 40 N was applied to the pullout repair sutures at 60°, the median MME decreased with increasing tension, with a significant reduction observed at 30 and 40 N compared with lower tension levels. Moreover, at tensions ≥30 N, the median MME remained <3 mm after centralization. MME was subsequently measured with 30 N tension applied to the pullout repair sutures. The median MME (mm) before MMPRT repair, after repair, and after centralization ranged from 7.6, 3.9, and 3 at 0° to 4.4, 3.5, and 2.6 at 120°, respectively. At 0°, MME was significantly smaller after centralization than before repair (P < .001) and also smaller than after repair (P < .006). At 120°, MME after centralization was significantly smaller than before repair (P < .001), and the difference among the 3 conditions was also significant (P = .03). Centralization resulted in the smallest MME at both flexion angles. The median MME before MMPRT repair, after repair, and after centralization at 30° were all smaller in the MME in the ER position. Conversely, the ER-IR differences were slight at 90°.

Conclusion:

Intraoperative ultrasound demonstrated that MMPRT repair reduced MME compared with the preoperative condition, and the addition of centralization further enhanced this reduction, yielding greater improvement than MMPRT repair alone.