Anterior cruciate ligament insufficiency is a major consideration in meniscal repair. The rate of successful repair is much higher in a reconstructed knee and should be performed at the same time.

Medial versus lateral is also a factor. Lateral repairs tend to be more vascular, tend to heal better, and tend to do more poorly if a total meniscectomy is performed. Therefore, all attempts should be made to preserve the lateral meniscus. With a total lateral meniscectomy, it’s been reported that there is up to a 90% chance of early degenerative changes.

Contraindications

Meniscal tears that are irreparable or can be best left alone are certainly contraindications to repair. Horizontal cleavage tears have minimal benefit with repair and are best done with a partial meniscectomy. Flap tears also should be best treated with partial meniscectomies. Meniscal tears that can be left alone include partial-thickness tears and stable tears of less than 7 mm.

Preoperative Planning and Timing of Surgery

Several authors have documented an improved outcome with meniscal repair earlier than 8 weeks after injury. The residual meniscus is deformed less, and the chance of a stable repair is improved. This is certainly not an emergency but should be done after the appropriate evaluation and imaging has been performed.

Patient and Equipment Positions

The leg should be prepped and draped to allow adequate circumferential exposure around the posteromedial and posterolateral joint line to allow easy exposure and needle passage. A formal leg-holder has advantages to help stabilize the knee and allow a varus or valgus force to be applied.

Special Instruments

Zone-specific single cannulas (Concept, Largo, FL) have been designed specifically for an inside-out technique. They work well in all zones of the meniscus, allowing passage or sutures in a horizontal or vertical mattress fashion. Vertical mattress sutures have been shown to have stronger pull-out strength and are currently the recommended suture of choice. Specific suture-retrieval instruments have also been designed to prevent inadvertent neurovascular injury with needle passage. A sterile spoon can also be used in their absence to protect the posterior structures. No. 2-0 Ethibond sutures specifically designed for meniscal repair are used.

Surgical Procedure

For a medial meniscus repair, a 4- to 6-cm longitudinal incision is made in the soft spot between the posterior border of the medial collateral ligament and the posterior

oblique ligament. While the knee is flexed, the pes anserine and sartorial branch of the saphenous nerve lie posterior to the joint line. Care must be taken throughout the entire procedure to prevent excessive retraction or entrapment of the nerve with sutures. This dissection is carried down to the posterior capsule, and the direct attachment of the semimembranosus to the posterior tibial tubercle should be palpated. The semimembranosus attachment is carefully released off the capsule, avoiding a capsular incision and arthrotomy. If this occurs, it should be repaired. The popliteal retractor is then inserted through the incision, behind the posterior capsule and medial head of the gastrocnemius. The meniscal rim and meniscal synovial junction are prepared with a meniscal rasp and shaver. This removes debris and increases a local vascular response. Visualization of the tear through the inter-condylar notch with a 70-degree scope and debriding the tear through a posteromedial portal are sometimes necessary. With the arthroscope back in the lateral portal, the zone-specific cannula is brought through the medial portal. The meniscal tear is reduced and held in place with the cannula. The 2-0 Ethibond sutures are then carefully placed under arthroscopic visualization, through the meniscus and into the stable rim, and brought out posteriorly under direct vision through the open incision protecting neurovascular structures. Ideally, vertical mattress sutures both on the superior and inferior surface are placed 4 mm apart. The arthroscope is switched to the medial portal to place the most anterior sutures through the lateral portal. The sutures are tagged individually and tied after all sutures have been placed.

For a lateral meniscus repair, a similar 4- to 6-cm vertical incision is made at the posterolateral corner of the knee. A longitudinal incision is made in the deep fascia, along the distal posterior margin of the iliotibial band with the knee flexed to 90 degrees. The lateral collateral ligament is kept anterior to the dissection. The biceps is retracted posteriorly. Using blunt and digital dissection, progress is made toward the midline of the knee. The popliteal retractor is placed beneath the lateral head of the gastrocnemius, protecting the posterior neurovascular structures. The meniscal rim and synovium must be properly prepared and debrided. Once again, sutures are placed under direct vision in a vertical or horizontal mattress fashion and brought out through the lateral incision. The knee is held in at least 45 degrees of flexion during suture passage. Most sutures can be placed safely through the medial portal. Care must be taken to visualize each needle as it penetrates the joint. These are tagged until final repair.

Dressings and Braces

A soft sterile dressing is applied, followed by a hinged post-up knee brace. Range of motion (ROM) is limited for 6 weeks to minimize stress on the repair. Full weight bearing and progressive ROM are started after 6 weeks.

Proper instrumentation, arthroscopic skill, and good assistance make this a simple and reproducible procedure. A properly placed skin incision and dissection prevent a struggle in needle retrieval.

Pitfalls and Complications

Neurovascular injury from poorly placed sutures is the most feared complication. Saphenous neuropathy is the most common nerve injury. Careful dissection and visualization prevent this from occurring.

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