Surgical Management of Discoid Lateral Meniscus With Anterior Peripheral Instability: Retaining an Adequate Residual Meniscus Volume

Video 1In this video, we demonstrate the surgical management for anterior instability of the discoid lateral meniscus (DLM) in which we highlight the surgical procedure to repair the anterior horn of the DLM, reassess the stability around the hiatus after the anterior horn is repaired, and the posterior horn of the DLM is surgically stabilized if necessary. This case involved the left knee of a 16-year-old boy who had anterior instability of his DLM. The DLM was confirmed by arthroscopic inspection from the anterolateral portal in the figure-four position. No widening of the hiatus was observed, and abnormal movement of the DLM from the flexion to extension position of the knee was confirmed from the lateral gutter view through the anterolateral portal. From the anteromedial portal view with the knee in extension, the DLM is shifted posteriorly, and connective tissue is observed between the meniscus and the capsule-like ramp lesion. The DLM is reduced to the anterior position, and redundant connective tissue is observed as the knee is ranged from extension to flexion. The connective tissue is easily removed with an arthroscopic shaver, and the tear becomes more apparent. Saucerization technique starts from the border between the anterior horn and central area of the DLM with a 45° punch introduced from the anteromedial portal parallel to the circumferential fibers of the anterior horn of the DLM while viewing from the anterolateral portal. Measurement of the resection length is performed with a ruler from the anteromedial portal. After a 1-cm resection length is confirmed by viewing from the anterolateral portal, saucerization with removal of the central area is performed with a punch using the anteromedial portal. After the width of the remaining anterior, body and posterior horn of the lateral meniscus is confirmed to be 10 mm, sutures with 2-0 FiberWire are then passed through the anterior horn using a Scorpion suture passer through the anterolateral portal. Subsequently, a NanoPass is introduced through the anterolateral portal and penetrates the lower side of the capsule to reach the tibial side of the DLM and retrieve the lower side of the suture. Next, the same procedure is performed to penetrate the upper side of the capsule to reach the femoral side of the DLM and retrieve the upper side of the suture. After the suture is tied using a sliding knot technique and secured with a knot pusher, the entire process is then repeated. The ultimate number of sutures is determined based on the length of the tear and number needed for stabilization. The distance between individual sutures is 3 mm. After stabilization of the anterior meniscus, the posterior meniscus is often pulled anteriorly. After resection, the length is remeasured, and the posterior portion is resected until reaching a point 10 mm from the hiatus. Meniscal instability is again evaluated with a probe, and if instability persists in the posterior aspect, an arthroscopic rasp can be used to freshen the sites around the hiatus. The dual meniscal repair needles loaded with 2-0 braided polyester sutures are inserted into the unstable portion of the meniscus, including the horizontal tear through the cannula positioned in the anteromedial portal. The suture needles are retrieved under direct visualization through a previously prepared lateral incision. The sutures are tied over the capsule after every four sutures had been passed. Stitches are placed at 3-mm intervals. After repairing the posterior portion, the width of the repaired meniscus was confirmed to be 10 mm from the hiatus, and stability of the meniscus is confirmed by viewing from the anterolateral portal and with a McMurray test from the anteromedial portal view.