Concomitant Medial Meniscal Root Repair with Extrusion Repair (Centralization Technique).

Background: Meniscal extrusion is a phenomenon in which a degenerative posterior horn tear, radial tear, or root tear results in displacement of the body of the meniscus medial to the tibial rim. The paramount function of the meniscus is to provide load distribution across the knee joint. Meniscal extrusion will prevent the meniscus from properly fulfilling this function and eventually leads to progression of osteoarthritis Description: Place the patient in the supine position with the knee supported in 90° of flexion and the feet at the edge of the operating table with foot-positioner support. First, meniscal root repair is performed with use of the suture pull-out technique, utilizing a cinch suture configuration to hold the root in place, and the suture tapes are fixed over the anterior cortex of the tibia with a suture button. Next, the meniscal body is arthroscopically assessed for residual extrusion from the medial tibial rim. Extrusion repair is indicated in cases with >3 mm of extrusion Alternatives: Alternatives include surgical procedures in which the root repair is performed with use of suture-anchor fixation Rationale: Root repair performed with the most common fixation techniques does not always reduce meniscal extrusion or restore meniscal function Expected Outcomes: Several surgical techniques have been described for the operative treatment of extrusion repair with use of centralization sutures Important Tips: A tight medial compartment is one of the most common problems encountered during a medial meniscal root repair. "Pie-crusting" of the superficial medial collateral ligament at the tibial insertion aids in improving the space, thereby reducing chondral damage during the root repair.It is challenging to achieve the correct inclination of insertion when inserting the suture anchor through a mid-medial portal. This limitation can be mitigated by utilizing a 16G or 18G needle before making the portal, as the needle direction, trajectory, and extent of accessibility within the joint will aid in proper portal placement and anchor insertion.Suture management is another technical challenge. Suture tape is first cinched to the root of the meniscus and then shuttled into the transtibial tunnel in order to discern the reducibility of the meniscus and the extent of possible extrusion correction. Then, extrusion repair is performed. This sequence allows the surgeon to avoid mixing of root-repair sutures and extrusion-repair sutures. Following insertion of the all-suture anchor, each suture limb is brought out through the anteromedial portal, passed through the nitinol loop from the lasso, and shuttled back through the mid-medial portal. Knot tying is performed through the mid-medial portal. Acronyms and Abbreviations: ACL = anterior cruciate ligamentPCL = posterior cruciate ligamentICRS grading = International Cartilage Research Society system for classification of cartilage lesionsKL grade = Kellgren-Lawrence system for classification of osteoarthritisMRI = magnetic resonance imagingMC = medial femoral condyleMPTA = medial proximal tibial angleLC = lateral femoral condyleHTO = high tibial osteotomyMCL = medial collateral ligamentAM = anteromedialKOOS = Knee injury and Osteoarthritis Outcome ScoreMME = medial meniscus extrusion.