Meniscal Root Tears: A State of the Art

Meniscal root tears - defined as complete radial tears within one cm of the bony insertion or direct avulsion of the root attachment - represent a biomechanically distinct injury pattern with a high and likely underestimated prevalence. By abolishing hoop stress transmission, root tears produce tibiofemoral contact mechanics equivalent to total meniscectomy, with attendant risks of meniscal extrusion, cartilage degeneration, and early osteoarthritis. Despite their mechanically important consequences, root tears are frequently underdiagnosed due to atypical clinical presentation and limited physician awareness, earning the designation of a "silent epidemic." Two epidemiologically distinct populations exist. Posterior medial root tears predominantly affect older (mean age 57 years), obese patients with varus alignment through a degenerative mechanism, while lateral posterior root tears disproportionately affect younger, active patients and are closely associated with an anterior cruciate ligament (ACL) injury. Physical examination findings are in many patients nonspecific, and diagnosis depends on a high index of suspicion combined with magnetic resonance imaging (MRI) evaluation. Treatment decision-making is guided by articular cartilage status, limb alignment, time elapsed from injury, and tear characteristics. Surgical repair - predominantly via transtibial pullout fixation - is most commonly considered the treatment of choice in symptomatic patients with preserved joint space, demonstrating superior functional outcomes and significantly lower rates of osteoarthritis progression and arthroplasty conversion compared with partial meniscectomy and non-operative management. Emerging suture anchor techniques have been introduced, but clinical evidence supporting their routine adoption still remains limited. Meniscal centralization addresses persistent postoperative extrusion; however, a level-2 randomized controlled trial demonstrated that meniscal extrusion increased in 96.2% of knees at 6 months regardless of centralization, underscoring the limitations of current techniques in achieving durable extrusion correction. Optimal management of concomitant deformities - including varus malalignment and high posterior tibial slope - remains an area of active investigation. Geographic variation in root tear epidemiology, particularly the higher degenerative medial root tear burden in East Asian populations attributable to floor-based activity patterns, underscores the global relevance of this injury. Future directions include standardization of patient selection criteria, development of biologics to enhance repair healing, further investigation of tibial slope correction, and establishment of consensus rehabilitation protocols. This state-of-the-art review provides a comprehensive synthesis of root anatomy, biomechanics, epidemiology, classification, clinical evaluation, surgical technique, and outcomes to guide evidence-based management and future directions.