Meniscus Root Injuries: More Questions than Answers?

Lika Dzidzishvili, MD, PhD, SPAIN Jorge Chahla, MD, PhD, UNITED STATES

ISAKOS eNewsletters   Current Perspective 2026   rating

Introduction

It is no longer a matter of debate that the natural history of meniscal root injuries is characterized by accelerated chondral degeneration and diminished joint survival^1,2. Even following technically successful root repair, joint degeneration frequently persists, and a substantial proportion of patients undergo joint replacement within the first 5 years of follow-up².

Despite meaningful advances in the field of meniscal root preservation, significant gaps in our understanding remain. What has often been referred to as a “silent pandemic” in knee preservation surgery continues to demand our attention, driving sustained scientific and clinical efforts aimed at improving patient outcomes and prolonging joint longevity.

Clinical Presentation

The clinical presentation of meniscal root injuries is heterogeneous. Lateral meniscal root tears typically are associated with acute traumatic events in young, physically active individuals. In contrast, medial meniscus posterior root (MMPR) tears often occur in middle-aged patients, predominantly women, and frequently are associated with minimal or no trauma, superimposed on pre-existing degenerative joint changes². These distinct patient profiles make medial-sided root tears particularly challenging to manage.

Surgical Considerations

Surgical technique remains a cornerstone of successful treatment. Anatomic repair of MMPR tears has been widely adopted and has been associated with a reduction in the rate of osteoarthritis (OA) progression (Fig. 1). However, radiographic progression of OA is still observed in a considerable number of patients, even at relatively short-term follow-up². From a biological perspective, second-look arthroscopy studies have demonstrated that a substantial proportion of repaired medial roots exhibit incomplete healing or residual laxity³. One of the key factors implicated in suboptimal postoperative outcomes and continued OA progression is persistent meniscal extrusion (ME). Consequently, mitigating postoperative ME has emerged as one of the most clinically relevant and actively debated topics in contemporary literature.

Fig 1. Arthroscopic anteromedial portal view of the left knee, demonstrating a complete medial meniscus root tear (A) and subsequent anatomic root repair using two transtibial tunnels (B).

Current evidence suggests that isolated root repair may not be sufficient to adequately address postoperative ME or to halt progressive joint degeneration. In carefully selected patients, the addition of concomitant procedures may provide meaningful benefit.

In recent years, considerable effort has been devoted to developing augmentation techniques aimed at improving the biomechanical environment of the repaired meniscus. Among these, meniscal centralization has gained increasing attention and is supported by emerging evidence (Fig. 2). Although surgical techniques vary, meniscal centralization is increasingly regarded as a promising strategy to restore meniscal position and potentially reduce postoperative extrusion.

Fig 2. Arthroscopic centralization procedure of the right knee, viewed from the anteromedial portal with a working anterolateral portal. A transtibial tunnel is created just lateral to the medial rim of the tibial articular surface (A). A horizontal mattress suture is then passed through the peripheral meniscus from inferior to superior and subsequently from superior to inferior, incorporating the meniscocapsular junction (B-D). Both ends of the suture tape are retrieved with a grasper and are shuttled through the cannulated sheath using a monofilament nitinol wire (E and F).

Clinical Outcomes

While early clinical outcomes following meniscal centralization generally have been favorable, the long-term effects of centralization on reducing ME and preserving joint integrity have yet to be fully established. A recent randomized study in which isolated MMPR repair was compared with MMPR plus meniscal centralization demonstrated that, although ME increased postoperatively in both groups, the increase was significantly less pronounced in the centralization group. Notably, magnetic resonance imaging (MRI) demonstrated no repair failures MRI at 6 months⁴. From a biomechanical standpoint, centralization has been shown to improve joint-contact mechanics and limit extrusion more effectively than isolated repair, potentially creating a more favorable environment for healing and enhanced chondroprotection⁵.

Nevertheless, several critical questions remain unresolved, including the optimal number and placement of centralization sutures. Furthermore, the current body of evidence is limited by small sample sizes, heterogeneity in surgical techniques, and a lack of long-term, high-quality comparative studies. These limitations underscore the need for cautious interpretation of early findings. Nevertheless, the initial results are encouraging and reflect meaningful progress in the field of meniscal root preservation.

Another key consideration in root-repair surgery is lower-limb alignment, particularly in medial-sided injuries. Varus malalignment has been identified as an important factor that may compromise root healing and accelerate medial compartment degeneration. Although the detrimental effect of varus alignment on postoperative outcomes is well recognized, the decision to perform a concomitant osteotomy--and the appropriate threshold for correction--remains complex. Surgeons must carefully balance the potential benefits of realignment against the risks associated with a more invasive procedure, especially in middle-aged and older patients.

Importantly, the relationship between alignment, ME, root healing, and OA progression is multifactorial. Many patients with MMPR tears present with pre-existing cartilage degeneration, which may substantially influence postoperative outcomes. In addition to anatomical factors, patient-specific variables such as sex, body-mass index, and baseline cartilage status likely play a critical role in determining prognosis. These considerations highlight the importance of individualized treatment strategies and realistic patient counseling.

Summary and Future Perspectives

While numerous questions related to meniscal root preservation surgery remain unanswered, ongoing research continues to refine our understanding and expand our therapeutic options. The field is steadily progressing toward more comprehensive, patient-specific approaches that may ultimately translate short-term improvements into durable joint preservation.

References

1. L. Dzidzishvili, E. Calvo, I.I. López-Torres, Medial Meniscus Posterior Root Repair Reduces but Does Not Avoid Histologic Progression of Osteoarthritis: Randomized In Vivo Experimental Study in a Rabbit Model, Am J Sports Med 51 (2023) 2964–2974. https://doi.org/10.1177/03635465231188527.
2. L.M. Krivicich, K.N. Kunze, K.C. Parvaresh, K. Jan, A. DeVinney, A. Vadhera, R.F. LaPrade, J. Chahla, Comparison of Long-term Radiographic Outcomes and Rate and Time for Conversion to Total Knee Arthroplasty Between Repair and Meniscectomy for Medial Meniscus Posterior Root Tears: A Systematic Review and Meta-analysis, Am J Sports Med 50 (2022) 2023–2031. https://doi.org/10.1177/03635465211017514.
3. L. Dzidzishvili, G. Pedemonte‐Parramón, E. Garcia‐Oltra, V. López, J.A. Hernández‐Hermoso, Lateral meniscus posterior root repairs show superior healing, reduced meniscal extrusion and improved clinical outcomes compared to medial meniscus posterior root repairs: A systematic review, Knee Surg. Sports Traumatol. Arthrosc. (2024) ksa.12478. https://doi.org/10.1002/ksa.12478.
4. L.V. Tollefson, A.W. Kajabi, E. Hedayati, K. Knutsen, T. Takahashi, J. Ellermann, R.F. LaPrade, Medial Meniscal Extrusion Increased on 6-Month Magnetic Resonance Imaging, Despite Successful Posterior Root Repair With or Without a Centralization Suture: A Randomized Controlled Clinical Trial, Am J Sports Med 53 (2025) 2808–2816. https://doi.org/10.1177/03635465251366443.
5. A. Deichsel, C. Peez, M.J. Raschke, R.G. Richards, B. Gueorguiev, I. Zderic, E. Herbst, C. Kittl, Arthroscopic Centralization of the Medial Meniscus Reduces Load on a Posterior Root Repair Under Dynamic Varus Loading: A Biomechanical Investigation, Am J Sports Med 52 (2024) 3030–3038. https://doi.org/10.1177/03635465241274791.

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