Meniscal root tears: from basic science to ultimate surgery.

BACKGROUND: In meniscal root tears (MRTs), the disruption of collagen fibers that provide hoop strength results in extrusion of the menisci, altering their biomechanical properties. Clinical diagnosis is difficult, but magnetic resonance imaging usually allows to identify the lesion. Located into the vascularized zone of the meniscus, management is preferentially arthroscopic, aimed at repairing the lesions with arthroscopic transosseous sutures or suture anchors. SOURCES OF DATA: PubMed, Cochrane Library, Google Scholar and Ovid Medline were searched in July 2012 to find literature on MRT tears. We reviewed the literature on biomechanics, imaging features and current treatments of these tears. Twenty-seven appropriate articles were identified and included in the study: 6 biomechanical studies, 11 imaging-based investigations for diagnosis, 1 study on clinical diagnosis and 9 studies about treatment. AREAS OF AGREEMENT: MRTs are infrequent, accounting for 10.1% of all arthroscopic meniscectomies. When the damage occurs to the roots, the transmission of the circumferential hoop tension is impaired and, consequently, the menisci tend to be displaced anteriorly and posteriorly, altering the biomechanics and possibly the kinematics of the knee. AREAS OF CONTROVERSY: Although the importance of the integrity of the meniscal roots is well established, their diagnosis and treatment are still controversial. GROWING POINTS: Biomechanical and clinical studies demonstrate that surgical repair of acute, traumatic meniscal root injuries fully restores the biomechanical features of the menisci, leading to pain relief and functional improvement. The current available surgical techniques for the meniscal root repair (suture anchors and pullout repair) are comparable. Level of evidence IV.