The post-traumatic meniscal extrusion, sign of meniscotibial ligament injury. A case series

Effectiveness of capsulodesis in ganglion cysts caused by a medial meniscotibial ligament tear and medial meniscus extrusion

INTRODUCTION AND IMPORTANCE

Meniscotibial ligament (MTL) has received attention as a major meniscus stabilizer. An MTL injury results in instability and extrusion of the meniscus. Cases of knee ganglion cyst formation due to an MTL tear and medial meniscus extrusion (ME) are extremely rare.

CASE PRESENTATION

A 42-year-old female Japanese childcare worker presented painful ganglion cysts on the proximal medial side of her left tibia. An MTL tear and medial ME were thought to be involved in the ganglion formation. Joint fluid flowed through the meniscotibial side of the extruded meniscus into the space between the medial collateral ligament and tibia, where the MTL tear acted as a check valve, forming ganglion cysts. Ultrasonography-guided aspiration of the ganglion was attempted, but ganglion cysts recurred within 1 month. We used an open excision for the ganglion cysts, and arthroscopic capsulodesis was performed to repair the MTL and internalize the medial meniscus to block the inflow route from the intra-articular space.

CLINICAL DISCUSSION

We performed capsulodesis, which repaired the MTL and internalized the medial meniscus to prevent the recurrence of the ganglion cyst. Three months have passed since the surgery, with no recurrence of knee pain or ganglion cysts, indicating good short-term results.

CONCLUSIONS

We encountered a rare case of ganglion cyst formation in the knee joint due to MTL tear and medial ME. Arthroscopic MTL repair and internalization of the meniscus by capsulodesis were effective in treating the ganglion cysts.

Extrusion and meniscal mobility evaluation in case of ramp lesion injury: a biomechanical feasibility study by 7T magnetic resonance imaging and digital volume correlation

Introduction: The existing body of literature on the biomechanical implications of ramp lesions is limited, leaving a significant gap in our understanding of how these lesions impact joint kinematics and loading in the medial compartment. This cadaveric biomechanical study aims to address this gap by employing an innovative Digital Volume Correlation (DVC) method, utilizing 7 Tesla Magnetic Resonance Imaging (MRI) images under various loading conditions. The primary objective is to conduct a comprehensive comparison of medial meniscal mobility between native knees and knees affected by grade 4 ramp lesions. By focusing on the intricate dynamics of meniscal mobility and extrusion, this work seeks to contribute valuable insights into the biomechanical consequences of medial meniscus ramp lesions. Materials and methods: An initial set of 7T MRI imaging sessions was conducted on two intact native knees, applying load values up to 1500N. Subsequently, a second series of images was captured on these identical knees, with the same loads applied, following the creation through arthroscopy of medial meniscus ramp lesions. The application of DVC enabled the precise determination of the three components of displacement and spatial variations in the medial menisci, both with and without ramp lesions. Results: The measured directional displacements between native knees and injured knees indicate that, following the application of axial compression load, menisci exhibit increased extrusion and posterior mobility as observed through DVC. Discussion: Injuries associated with Subtype 4 medial meniscus ramp lesions appear to elevate meniscal extrusion and posterior mobility during axial compression in the anterior cruciate ligament of intact knees. Following these preliminary results, we plan to expand our experimental approach to encompass individuals undergoing weight-bearing MRI. This expansion aims to identify meniscocapsular and/or meniscotibial insufficiency or rupture in patients, enabling us to proactively reduce the risk of osteoarthritic progression.

Relationship between medial meniscus extrusion and damage to medial stabilizers: Should extrusion be considered significant only when more than 3 mm?

BACKGROUND

This study was conducted with patients with anterior and medial extrusion of the medial meniscus (MM-AE, MM-ME) to investigate the relationship of the amount of extrusion with damage to the meniscus, meniscofemoral ligament (MFL), meniscotibial ligament (MTL), presence of effusion, osteoarthritis (OA) grade and other medial stablizers. A cut-off value for significant MM-ME was also suggested.

METHODS

All patients aged 18 and above who had measurable MM extrusion on knee MRI were included. Patients with acute injury detected on knee MRI and any disease that could disrupt the anatomy were not included. The relationship between the amount of MM-AE, MM-ME and the investigated comorbidities were evaluated. The patients were divided into two: those with and without positive findings for each comorbidities. The amount of MM-AE, MM-ME were evaluated. ROC analysis was undertaken for significant differences, and cut-off values were determined.

RESULTS

There was a correlation between MM-ME and age, weight, and BMI (p < 0.001, p = 0.027, p = 0.025, respectively). The amount of MM-ME was higher in the groups with OA (p = 0.007), MTL damage (p < 0.001), MFL damage (p < 0.001), meniscus damage (p < 0.001), effusion (p < 0.001), and the amount of MM-AE was higher in the groups with OA (p = 0.042), effusion (p = 0.002). The cut-off values of MM-ME were determined to be 2.69 mm (MTL), 2.65 mm (MFL), 2.49 mm (meniscus), and 2.85 mm (OA).

CONCLUSION

OA grade, effusion, and meniscus, MTL, and MFL damage were all found to be related to the amount of MM-ME. MM-ME values 2.49-2.85 mm may indicate meniscus, MFL, MTL damage and OA.

The meniscotibial ligament role in meniscal extrusion: a systematic review and meta-analysis

INTRODUCTION

The meniscotibial ligament (MTL) limits extrusion of the medial meniscus (MM). While meniscal extrusion may be detrimental to knee joint biomechanics, the role of the MTL in meniscal extrusion is debatable. We sought to perform a systematic review and meta-analysis to evaluate the role of the MTL and surgical techniques for MTL repair.

MATERIALS AND METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines we searched PubMed, Cochrane Library, and Embase for: (("Meniscotibial") OR ("Coronary") OR ("Ramp")) AND ("Extrusion"). After screening and applying eligibility criteria, data were extracted for MTL pathology types ("traumatic" ruptures or "induced" injuries) and meniscal extrusion. A meta-analysis evaluated the mean difference of extrusion between "intact" MTLs (native or repaired) and "injured" MTLs (induced or traumatic). We further performed a subgroup analysis between traumatic and induced MTL lesions.

RESULTS

This systematic review included six studies, which all evaluated MM extrusion. There were 74 knees with induced MTL injuries and 19 knees with traumatic MTL ruptures. Study designs were heterogenic and utilized three types of MTL repair procedures. The meta-analysis included 18 human knees and revealed that sectioning the MTL created a 2.92 mm [- 0.18 to 6.03] MM extrusion, while MTL repair decreased MM extrusion by - 2.11 mm [- 3.03 to - 1.21].

CONCLUSIONS

MTL injury may result in approximately 3 mm of MM extrusion, while repair of the MTL can decrease extrusion by 2 mm. Several novel surgical techniques exist to repair the MTL. However, studies reporting clinical outcomes of these various procedures are scarce.

Meniscus tears treatment: The good, the bad and the ugly-patterns classification and practical guide

Over the years, several studies demonstrated the crucial role of knee menisci in joint biomechanics. As a result, save the meniscus has become the new imperative nowadays, and more and more studies addressed this topic. The huge amount of data on this topic may create confusion in those who want to approach this surgery. The aim of this review is to provide a practical guide for treatment of meniscus tears, including an overview of technical aspects, outcomes in the literature and personal tips. Taking inspiration from a famous movie directed by Sergio Leone in 1966, the authors classified meniscus tears in three categories: The good, the bad and the ugly lesions. The inclusion in each group was determined by the lesion pattern, its biomechanical effects on knee joint, the technical challenge, and prognosis. This classification is not intended to substitute the currently proposed classifications on meniscus tears but aims at offering a reader-friendly narrative review of an otherwise difficult topic. Furthermore, the authors provide a concise premise to deal with some aspects of menisci phylogeny, anatomy and biomechanics.