Arthroscopic Meniscus Repair

Inside-Out Technique

• The inside-out meniscus repair technique remains the gold standard against which other repair modalities are compared. This is ideal for posterior meniscus tears, allowing for capture of multiple, longitudinally oriented collagen cables when a vertical suture technique is used. Patient selection remains critical to acceptable outcomes.

Important Points

• Tear location and knee ligamentous stability are the most important factors that determine successful meniscus repair outcome.

• The anteromedial working portal should be made based on meniscus repair location.

Clinical and Surgical Pearls

• The use of double-loaded 2-0 or 0 nonabsorbable sutures with long flexible needles is recommended.

• The posterior capsular incision should be made such that the length of the incision starts at the level of the joint line. Placement of the incision here facilitates capture of the flexible needles during suture passage.

Clinical and Surgical Pitfalls

• Beware of the infrapatellar branch of the saphenous nerve during medial meniscal repairs. Entrapment of this nerve is possible during tying of the passed sutures. Such nerve entrapment is a possible cause of acute postoperative pain and formation of a neuroma.

• Beware of the peroneal nerve during lateral repairs. This nerve can be entrapped by meniscal sutures if the deep retractor is not placed deep to the gastrocnemius. Confirm that the retractor sits directly behind the capsule before suture passage. The posterior capsule should be directly visualized before sutures are tied laterally.

• Once the sutures have been passed, each suture should be sequentially tied (central to peripheral) with the leg in extension. This prevents tethering of the posterior capsule by the meniscal sutures and decreases the likelihood of a postoperative flexion contracture.

Numerous studies have confirmed the biomechanical importance of the meniscus and its relation to the development of early degenerative changes in the knee with its incompetency.1–5 Thus meniscal repair is preferable to meniscectomy whenever feasible. Since the introduction of meniscus repair in 1885 by Annandale,⁶ multiple repair techniques have been developed, both open and arthroscopic. The development of inside-out repair techniques and devices revolutionized the management of repairable meniscus tears, and use of such techniques and devices is currently the gold standard for meniscus repair. Such repair techniques are ideal for posterior meniscus tears and allow for the capture of multiple, longitudinally oriented collagen cables when a vertical suture technique is used. This chapter discusses the inside-out meniscus repair technique in detail.

Preoperative Considerations

History

A detailed history remains critical to the accurate diagnosis of a meniscus tear. The timing of injury and the exact mechanism, associated injuries, duration of symptoms, previous treatments, and exacerbating and alleviating factors are important points of discussion at the time of the initial visit.

Indications and Contraindications

Indications for meniscus repair have remained constant throughout the evolution of repair techniques. The vascularity of the meniscus has been well described and remains critical to the treatment algorithm. Only the peripheral 10% to 30% of the meniscus is vascularized, supplied by the medial and lateral genicular arteries.⁸ DeHaven classified tears in the peripheral 3 mm as vascular (referred to as the red-red zone), those more than 5 mm from the meniscocapsular junction as avascular (white-white zone), and those in between as variable (red-white zone).⁹ Meniscus tears in the red-red zone have the best ability to heal because of the vascularity of the meniscus and thus are often repairable. However, reports have documented successful repair of tears in the avascular zone in young patients.^10,11 In addition, orientation of the tear must be considered. Typically, longitudinal vertical tears and bucket-handle tears are most amenable to repair. Degenerative tears or those with multiple horizontal cleavage planes are indications for partial meniscectomy.¹² Often, undersurface tears that are oblique in orientation extend from a vascular to an avascular zone and are problematic with regard to complete healing after repair. Patient compliance with the required rehabilitation course and initial limited weight-bearing status remain important for a successful outcome after meniscus repair. Finally, an intact ACL, whether reconstructed or native, has been shown to be critical to the success of the meniscus repair.¹³