Assess the location of the meniscal tear and determine the repairability of the lesion. Determine optimum medial portal placement using an 18-gauge spinal needle and direct arthroscopic visualization to create medial working portal. Optimum position is achieved when the needle enters just above the anterior medial meniscus parallel to the tibial joint surface (Figure 1).
Avoid placing the portal too superior. Ensure the medial portal is large enough to readily pass the inserter and suture cutter. Measure the distance from the back side of the meniscus to the desired needle penetration point at the repair site using a meniscal depth gauge (Figure 2).
Position the MaxFire™ MarXmen™ Inserter
Insert the disposable MaxFire™ MarXmen™ inserter into the joint. Both straight and curved-up cannulas are available to optimize implant positioning for repair. Use of a probe through the medial portal can help determine whether a straight or curved cannula would be optimal. To maximize safety, all posterior horn tears whether medial or lateral, should be approached from the medial portal.
Mid-body tears can be approached from the contralateral portal. Anterior horn tears can be approached from the ipsilateral portal (Figure 3). Under direct arthroscopic visualization, maneuver the cannula tip against, or adjacent to, the desired portion of the meniscus (Figure 4).
Note: Avoid excessive torque of the cannula upon insertion into the joint.
Inserting Needle Sled
Place the long finger in the space between the trigger and the body of the inserter (Figure 5). Retract the cannula and expose the needle sled by pushing the thumb wheel and rolling it upwards (Figure 6). This will set the initial deployment length setting. Note: Do not squeeze the trigger until the needle sled is in position to deploy the first anchor. The needle deployment length is adjusted by rolling the thumb wheel.
Laser markings on the needle sled and a dial on the body of the inserter can be used to verify deployment depth. Each laser marking on the needle sled represents a 2mm increment. Insert the needle sled into the desired location in the meniscus with the depth indicator set at 10mm (Figure 7). Once the sled has been inserted into the meniscus, set the depth to the pre-determined setting (Figure 8) and advance the cannula until it is flush with the meniscus (Figure 9).
Deploy the First Anchor
Once the needle sled is advanced completely into the meniscus at the desired length, hold gentle but firm pressure against the meniscus. Position the middle finger over the outside of the trigger. Squeeze the trigger and maintain pressure to deploy the implant (Figures 10 A, B & C). A gentle click will be felt once the implant has been completely advanced to the desired length. Release the trigger and pull the needle sled gently from the meniscus (Figures 11A & B).
Note: Squeeze the trigger completely once for each anchor. Multiple trigger pulls (particularly with the insertion of the first anchor) will deploy both anchors at the same location.
Deploy the Second Anchor
Re-position the needle sled to a new desired location on the meniscus 5 – 10mm from the first anchor (Figure 12). Note: the needle sled may be retracted into cannula while moving to new position if desired to prevent inadvertent chondral injury. Adjust depth of needle penetration to 10mm. Advance the needle sled into the meniscus in the desired location taking care not to impale the suture or damage the articular cartilage. This is particularly important when creating a vertical mattress stitches.
Set depth to desired setting and advance needle sled into meniscus. Once the needle sled is advanced completely into the meniscus at the desired length, hold gentle but firm pressure against the meniscus. Squeeze the trigger and maintain pressure to deploy the implant (Figure 13). A gentle click will be felt once the implant has been completely advanced to the desired length.
Release the trigger and pull the needle sled gently from the meniscus. Remove the MaxFire™ MarXmen™ inserter from joint (Figure 14).
Vertical Mattress Technique: Insert the first anchor on the superior meniscal rim or surface. Implants in this superior meniscal location will require shorter distances of deployment since the depth of meniscus will be less compared to the inferior meniscus. Insert the second anchor in the inferior meniscus. Needle depth penetration will need to be increased to ensure deployment of the anchor through the meniscus and capsule. (Figure 15).
Tension the Suture
A large loop and a free strand of suture will remain outside the portal site (Figure 16). Grab each of the loop strands leaving the single strand free. Pull on the strands to determine which strand tightens the inner short loop at the meniscus. Note: Pulling the appropriate strand should NOT result in shortening of the single strand outside of the joint. With the appropriate loop strand identified, alternately pull the appropriate loop strand and the single strand (Figure 17). Visualize tightening the suture at the meniscal repair site. Once a small loop remains outside of the joint, simply pull the single strand until the second large loop is seated against the meniscal tissue (Figure 18).
Cut the Suture
Slide the suture into the opening of the disposable MaxCutter™ Suture Cutter. Insert the cutter through the portal and to the level of the meniscus. Advance the cutter lever to sever the suture (Figure 19). Assess fixation with a probe. Fixation is now complete (Figure 20)
Note: It is recommended that suture anchors from a given pair (single MaxFire™ construct) be spaced 5 – 10mm apart. Each MaxFire™ anchor construct should also be spaced 5 – 10mm apart to ensure subsequent anchors are not inserted into, or too close, to previously placed anchors.