Complete radial meniscus tears constitute a unique subset of meniscus injuries, resulting in disruption of the circumferential fibers and compromising their ability to with-stand hoop stresses. This results in decreased contact area and increased tibiofemoral contact pressure, which can lead to the onset of an accelerated joint degenerative process. The proportion of radial tears has been recently reported to be 10% to 23% of meniscus tear pat- terns in the adult population, greater than previously reported. Radial meniscus tears are common in active patients and are frequently associated with anterior cruciate ligament (ACL) and multiligament knee injuries.
Traditionally, radial tears were addressed by means of partial or total meniscectomy because they were considered to be unrepairable. However, meniscectomy for a complete radial meniscus tear is associated with long-term biomechanical consequences and an accelerated degenerative process of the knee. Importantly, a subset of these patients may ultimately undergo meniscus transplantation to improve symptoms and to attempt to preserve the joint. With an increased emphasis on the detrimental long-term effects of meniscectomy, meniscus preservation is paramount whenever possible. This concept was reinforced by a recent systematic review that reported improved patient outcomes with the repair of radial meniscus tears when compared with meniscectomy at longer term follow-up.
Existing techniques to address radial meniscus tears include all-inside horizontal mattress repair, transtibial pullout repair, and inside-out repair with either single, double, or crossed horizontal mattress sutures. Repair strength is an important factor because of the effects on healing potential and postoperative rehabilitation protocols. A recent biomechanical study compared a 2-tunnel transtibial pullout repair technique to a standard horizontal repair technique and reported improved performance with cyclic loading with the former. In this regard, this technique has been reported to produce durable results in a case report at early follow-up.
While there is debate over whether the repair of complete radial tears will result in adequate biomechanical performance and healing, few debate the benefits of repair- ing vertical meniscus tears because of the reported excellent outcomes for this tear pattern. Patients undergoing vertical tear repair therefore represent a relevant comparison group for those undergoing radial tear repair. Given the paucity of reported outcomes of radial meniscus tear repair techniques, the purpose of this study was to com- pare the outcomes for patients who underwent 2-tunnel transtibial pullout repair of a radial meniscus tear versus patients who underwent inside-out repair of a vertical meniscus tear at a minimum 2 years of follow-up. The hypothesis was that outcomes for radial tear repair were comparable with those for vertical tear repair.