Meniscus regeneration with biologic or synthetic scaffolds

Efforts should be made to preserve the meniscus, but if this is not possible, meniscus regeneration with biologic or synthetic scaffolds may be an option. Multicenter clinical trials and reports have demonstrated new tissue formation and fewer reoperations after collagen scaffold implantation compared with partial meniscectomy alone for greater than 10 years. A synthetic scaffold showed biocompatibility and successful early tissue ingrowth at 2 and 5 years. Research continues to develop and refine novel acellular scaffolds to support regeneration and regrowth of lost or damaged meniscus tissue.

Meniscus scaffolds are indicated for partial meniscus loss, whereas meniscus allografts are indicated in the face of total or near total meniscus loss.

Two meniscus scaffolds, one biologic and one synthetic, are available for human clinical use in the United States and much of the world.

Intact anterior and posterior horn attachments and an intact rim of the involved meniscus are required for suture fixation of the scaffold.

Knee ligamentous stability and proper axial alignment are necessary before scaffold implantation.

Meniscus scaffolds are contraindicated in knees with advanced osteoarthritis.

Successful scaffold implantation is technique specific and dependent.

Proper postoperative rehabilitation must be followed to avoid early damage to the scaffold.

Preparation of the implant site results in a full-thickness meniscus defect with no residual flaps or loose or degenerative tissue.

The defect size must be measured accurately, and then the implant should be trimmed by oversizing by about 10%.

The implant can be delivered into the joint with an atraumatic clamp through an extended portal.

The scaffold must be sutured to the meniscus rim, preferably with all-inside or inside-out sutures.

Do not overtighten the sutures, as this could damage the implant.

If the medial compartment is tight, partial release of the medial collateral ligament should be considered (using the so-called “pie crusting” technique).

If there are comorbidities (e.g., axial malalignment, full-thickness chondral injuries, ligament instability), consider staging the procedures to correct comorbidities first in order to protect the scaffold.

Inadequate lesion preparation may result in the implant not making uniform contact with the host meniscus rim.

Improper measuring of the defect or cutting the implant too short leaves the defect incompletely filled.

Excessive tension on the fixation sutures can damage the scaffold implant.

Damage to the articular cartilage with the implant delivery device or with the suture devices can occur, especially in a tight knee.

Placing the implant in a knee with untreated comorbidities can result in excessive biomechanical forces on the scaffold and lead to its damage or prevent adequate cell ingrowth and new tissue formation.