Introduction: Meniscal Allograft Transplantation

The preoperative planning for this procedure should include the identification of the meniscal pathology and obtaining sizing radiographs;^1,2 confirming the sizing, site, and side of the tissue match from the tissue bank; and assessing ligamentous stability, alignment, and articular cartilage status. Any ligamentous abnormalities, malalignment, or articular cartilage pathology should be corrected either concomitantly or staged. At the time of surgery, before the initiation of anesthesia, confirm that the meniscus allograft is in the operating room (OR) and that it is the appropriate patient, size, side, and site. Three techniques will be reviewed: the double bone plug,³ the dovetail technique,⁴ and the slot technique.⁵

General Tibial Preparation

FIGURE 14-1

FIGURE 14-2

FIGURE 14-3

FIGURE 14-4

Double Bone Plug Technique

Graft Preparation

1. The bone plugs can either be prepared freehand or by using a coring reamer.

2. The anterior bone plug should be 8 mm in diameter and 10 mm long. The posterior plugs should be 6 to 7 mm in diameter and 8 mm in length. (Fig. 14-5)

3. The freehand technique is performed using rongeurs and high-speed burr.

4. If using a coring reamer, place a 2.4-mm guide pin through the center of the anterior and posterior horn attachment sites, extending through the bone block. (Fig. 14-6)

5. Insert a collared pin into the bottom of the bone bridge.

6. Place a coring reamer of appropriate size over the collared pin and create a bone dowel. (Fig. 14-7)

7. Trim the dowels to the appropriate length.

8. Pass a nonabsorbable size 0 or 1 suture up through the posterior plug. Place a horizontal mattress suture through the meniscal tissue at the attachment site. Pass the suture down through the bone plug. (Fig. 14-8)

FIGURE 14-5

FIGURE 14-6

FIGURE 14-7

FIGURE 14-8

Posterior Tibial Tunnel Preparation

1. Using an anterior cruciate ligament (ACL) tibial guide, place the tip of the guide on the posterior horn attachment such that the 2.4-mm guide wire will be centered. (Fig. 14-9)

2. Select a cannulated reamer 1 mm larger than the posterior plug diameter, and drill a tunnel from the anterior tibia exiting at the posterior horn attachment. (Fig. 14-10)

3. Debride and smooth the intraarticular portions of the tunnel using rasps and a shaver.

FIGURE 14-9

FIGURE 14-10

Placement of the Meniscus Allograft

1. Create a limited or miniarthrotomy. (Fig. 14-11)

2. Pass the suture attached to the posterior horn through the previously created posterior tunnel utilizing a suture retriever. (Fig. 14-12)

3. Place a pull-through suture guide into the body of the meniscus at the junction of the posterior and middle thirds. It is often helpful to use two separate pull-through sutures. (Fig. 14-13)

4. Create a small posteromedial skin incision, and dissect the subcutaneous tissue to the capsule.

5. Pass the pull-through guide suture through the knee at the corresponding position in the remnant meniscus such that it exits the knee through the posteromedial incision.

6. Pass the posterior bone plug through the notch, guiding it into the posterior tunnel using the posterior tunnel suture and a blunt instrument to help position it. (Fig. 14-14)

7. Use the pull-through guide suture and blunt instrumentation to reduce the remainder of the body of the meniscus. (Fig. 14-15)

8. Secure the posterior bone plug by tying the sutures attached to the bone plug over a button on the anterior tibia.

FIGURE 14-11

FIGURE 14-12

FIGURE 14-13

FIGURE 14-14

FIGURE 14-15

Placement of Anterior Plug

1. After securing the posterior plug and reducing the body of the graft, seat the meniscus by placing it through a range of motion. This will also facilitate the selection of the attachment site for the anterior horn.

2. Utilizing a 2.4-mm guide pin, place it into the center of the area of anterior attachment, keeping it as perpendicular to the tibial joint surface as possible. (Fig. 14-16)

3. Place an 8-mm cannulated reamer over the guide wire, and create a bone tunnel 10 mm deep.

4. Reduce the anterior plug into the tunnel. Although this allows for press fit fixation, additional stabilization may be required with nonabsorbable size 0 or 1 sutures. (Fig. 14-17)

FIGURE 14-16

FIGURE 14-17

Securing the Meniscal Allograft

1. Secure the meniscus utilizing either an inside-out technique, an all-inside technique, or a combination of both.

2. If using the inside-out technique, use 2-0 absorbable sutures and pass them through the previously created posteromedial or posterolateral incision. (Fig. 14-18)

3. An all-inside technique is often used in the posterior body. This technique can be difficult if there isn’t adequate meniscal rim to pass the fixation device into.

4. The anterior horn and body sutures can often be passed under direct visualization. (Fig. 14-19)

FIGURE 14-18

FIGURE 14-19

Dovetail Technique