Top Ten Pearls for a Successful Transtibial Pull-Out Repair of Medial Meniscal Posterior Root Tears With a Concomitant Centralization Stitch

Abstract

Although historically overlooked, medial meniscus posterior root (MMPR) tears are now increasingly recognized as a substantial cause of biomechanical impairment and morbidity. MMPR tears, when left untreated, are strongly correlated to meniscal extrusion and ultimately lead to altered kinematics and loading functionally equivalent to a total meniscectomy. To prevent progressive joint degeneration and alleviate pain while re-establishing native joint kinematics, MMPR repair is generally recommended in appropriately selected patients. In this Technical Note, the authors describe a detailed checklist with 10 crucial points of emphasis when performing the gold-standard transtibial pull-out repair of the MMPR, with an additional centralization stitch, providing technical pearls backed up by previous literature and ample experience treating this condition.

Fig 1

Magnetic resonance imaging of medial meniscal root tear of right knee. (A) Coronal T2 view of the medial meniscal root tearing with associated tibial subchondral bone edema, (B) evidence in the sagittal T2 view of the presence of the “ghost sign,” and (C) evidence in the coronal T2 view of medial meniscal extrusion with femoral subchondral bone edema.

Fig 2

Routine arthroscopic probing of the meniscal root of the right knee. With a high anterolateral viewing portal and working anteromedial portal just proximal to the medial meniscus, a probe is inserted. Probing of the root should be considered a procedural step during arthroscopic articular inventory and will reveal insufficiency of the meniscus root whenever a tear is present. (MFC, medial femoral condyle; MM, medial meniscus; TP, tibial plateau.)

Fig 3

Cadaveric depiction of LaPrade’s classification of meniscal root tears in a right knee. (A) Type I is defined as a partial tear but with stable pattern; (B) type II, which is a complete radial tear near the root attachment, with 3 subcategories (<3 mm, 3-<6 mm, and 6-9 mm from the center of the attachment)—this is the most common root tear pattern; (C) type III tears are considered “disaster tears” and consist of a complete root detachment combined with a bucket-handle tear; (D) type IV, where an oblique tear propagates into the root attachment site; and (E) type V tears, which are bony avulsions from the attachment site, often found as meniscal ossicle chronically during arthroscopy.

Fig 4

Effect of medial collateral ligament pie crusting while arthroscopic viewing of the medial meniscal root tear from the anterolateral portal of the right knee. (A) Evidence of a LaPrade type II tear in a tight medial tibiofemoral compartment prior to medial collateral ligament pie-crusting procedure of a right knee. (B) Increased visualization and access to the posterior horn and root attachment of the medial meniscus after medial collateral ligament pie crusting. (MFC, medial femoral condyle; MMPH, medial meniscus posterior horn; TP, tibial plateau.)

Fig 5

Anatomic tibial tunnel placement with arthroscopic viewing of the medial meniscal root tear from the anterolateral portal and a working anteromedial portal of the right knee. (A) The anatomic footprint of the meniscal root is decorticated using a curved curette and the area is then further prepared with an arthroscopic shaver. (B) A curved aimer guide is positioned at the desired site of the posterior tunnel. (C, D) A 2.7-mm cannulated sheath with a guide pin is then positioned in the aimer guide set at 55° and drilled to create the first tunnel. (E) After the first tunnel is drilled, a second tunnel is placed 5 mm anterior to the first using an offset guide.

Fig 6

Suture passage with arthroscopic viewing of the medial meniscal root tear from the anterolateral portal and a working anteromedial portal of the right knee. Using a self-retrieving all-inside suture-passing device, the first suture (upper arthroscopic view image) is inserted into the posterior aspect of the detached medial meniscal posterior root approximately 5 mm medial from the lateral meniscal edge going from the tibial to the femoral side and pulled back through the cannula on the anteromedial portal. After passage of the first suture (as demonstrated in Fig 7), the steps are repeated with the second suture (lower arthroscopic view image), positioning it through the midportion of the root, anterior to the placement of the first suture, in order to avoid eversion of the central free end of the meniscus.

Fig 7

Suture shuttling in a 2-tunnel transtibial repair with arthroscopic viewing from the anterolateral portal and a working anteromedial portal of the right knee. A monofilament nitinol wire is inserted into the posterior transtibial tunnel and retrieved with a grasper through the anteromedial cannula to allow for the first suture (upper arthroscopic view image) to be shuttled through the posterior tunnel without tangling. The nitinol wire is pulled out of the tibial tunnel, which shuttles the repair suture down and out of the tunnel. The shuttling steps are then repeated with the second repair suture (lower arthroscopic view image), as similarly noted in Figure 6, through the more anterior transtibial tunnel.

Fig 8

Centralization stich with arthroscopic viewing from the anteromedial portal and a working anterolateral portal of the right knee. (A) A transtibial tunnel is drilled just lateral to the medial rim of the tibial articular surface with a cannulated sheath through the same aiming guide used earlier, now placed through the anterolateral portal. (B-D) A horizontal mattress suture is passed from bottom to top on the periphery of the meniscus, and then from top to bottom, incorporating the meniscocapsular junction. (E, F) Both ends of the suture tape are then retrieved with a grasper and shuttled through the cannulated sheath with the aid of the monofilament nitinol wire.

Fig 9

Tensioning of the sutures and anchor fixation of the medial meniscal root repair construct under arthroscopic visualization from the anterolateral portal of the right knee. All sutures are manually tensioned under direct arthroscopic visualization, ensuring optimal reduction and tension of the repair construct.