Role of the Meniscofemoral Ligaments in the Stability of the Posterior Lateral Meniscus Root After Injury in the ACL-Deficient Knee

Predicting incident radiographic knee osteoarthritis through quantitative meniscal lesion parameters: data from the osteoarthritis initiative

BACKGROUND

This study investigates the potential of novel meniscal parameters as predictive factors for incident radiographic knee osteoarthritis (ROA) over a span of four years, as part of the Osteoarthritis Initiative (OAI) study.

OBJECTIVES

Quantitative measurements of meniscal parameters alteration could serve as predictors of OA's occurrence and progression.

METHODS AND MATERIALS

A nested matched case-control study design was used to select participants from OAI study. Case knees (n = 178) were defined as those with incident ROA (Kellgren Lawrence Grade (KLG) 0 or 1 at baseline (BL), evolving into KLG 2 or above by year 4). Control knees were matched one-to-one by sex, age and radiographic status with case knees. The mean distance from medial-to-lateral meniscal lesions [Mean(MLD)], mean value of tibial plateau width [Mean(TPW)] and the mean of the relative percentage of the medial-to-lateral meniscal lesions distance [Mean(RMLD)] were evaluated through coronal T2-weighted turbo spin echo (TSE) MRI at P-0 (visit when incident ROA was found on radiograph), P-1(one year prior to P-0) and baseline, respectively. Using the imaging data of one patient, the mechanism was investigated by finite element analysis.

RESULTS

Participants were on average 60.22 years old, predominantly female (66.7%) and overweight (mean BMI: 28.15). Mean(MLD) and Mean(RMLD) were significantly greater for incident knees compared to no incident knees at baseline, P-1 and P-0. [Mean(MLD), Mean(RMLD); (42.56-49.73) mean ± (7.70-9.52) mm SD vs. (38.14-40.78) mean ± (5.51-7.05)mm SD; (58.61-68.95) mean ± (8.52-11.40) mm SD vs. (52.52-56.35) mean ± (6.53-7.85)mm SD, respectively]. Baseline Mean(MLD) and Mean(RMLD), [Adjusted OR, 95%CI: 1.11(1.07 to 1.16) and 1.13(1.09 to 1.17), respectively], were associated with incident ROA during 4 years, However, Mean(TPW) [Adjusted OR, 95%CI: 0.98(0.94 to 1.02)] was not associated with incident ROA during 4 years. While Mean(TPW) at P-1 and P-0 was not associated with the risk of incident ROA, Mean(MLD) and Mean(RMLD) at P-1 and P-0 were significantly positively associated with the risk of incident ROA.

CONCLUSIONS

The meniscal parameters alteration could be an important imaging biomarker to predict the occurrence of ROA.

A Modified Suture Hook Technique for Lateral Meniscus Tears: Chinese Union Suture Procedure (CUSP)

Tears in the lateral meniscus, especially the body and posterior horn, are a common sports medicine injury, and severe cases require arthroscopic treatment. However, the narrow space in the posterolateral compartment of the knee joint makes the surgeon's operation inconvenient. Here we have proposed a suture technique suitable for lateral meniscus posterior horn/body injuries known as the Chinese Union Suture Procedure. The introduction of the posteromedial-transseptal portal allows for a suitable angle of operation for suture hooks in case of injuries to the posterior horn of the lateral meniscus or the popliteal hiatus area of the lateral meniscus. The use of the continuous sewing machine-like suture technique allows surgeons to more quickly and flexibly address meniscus tears. We have also introduced a retractor as an auxiliary tool for portal establishment. In conclusion, our improved technique enables vertical mattress suturing for meniscus tears, and it allows for tying knots on the tibial surface of the meniscus, which is challenging to achieve with traditional all-inside suture hook techniques. Our technique combines flexibility, speed, and cost-effectiveness, making it valuable for clinical applications.

Anterior Cruciate Ligament Rupture Combined with Complete Radial Tear of the Posterior Horn of the Lateral Meniscus: Suture or Resection?

Anterior cruciate ligament (ACL) rupture often presents with a tear of the posterior horn of the lateral meniscus. There is no clear preference between ACL reconstruction with suture and resection of the meniscus. We aimed to compare the clinical efficacy of ACL reconstruction with suture versus resection in patients presenting with arthroscopic ACL rupture and radial complete tear of the posterior corner of the lateral meniscus. We retrospectively analyzed 157 patients with ACL rupture and complete radial tear of the posterior horn of the lateral meniscus. Between May 2010 and April 2015, 86 of 157 patients underwent ACL reconstruction and meniscus suture (study group, 54.78%) and 71 of 157 patients underwent ACL reconstruction and meniscus resection (control group, 45.22%) in our department. All patients were monitored over the 12 to 72-month follow-up period. The primary evaluation indices were the Lysholm scores, the International Knee Documentation Committee (IKDC) scores, pivot shift test, the Barret criteria, and magnetic resonance imaging (MRI) findings of meniscal healing. The majority of 157 patients were relatively young men (29.64 ± 7.79 years) with low body mass index (BMI) (23.79 ± 2.74). The postoperative Lysholm and IKDC scores of the two groups were significantly improved over the corresponding preoperative scores (p < 0.05). The clinical results and excellent and good rates were significantly better for the study group than for the control group (both, p < 0.05). MRI showed that the meniscal healed rate of the study group was 96.51%. There was no significant difference in BMI between subgroups for any functional outcome. For patients with ACL rupture and complete radial tear of the posterior horn of the lateral meniscus, ACL reconstruction and both simultaneous suture and resection of the posterior horn of the lateral meniscus were found to be safe and effective. There was no association between outcomes and BMI. However, the former was associated with a superior long-term clinical effect and may restore the integrity of the meniscus and is particularly recommended for young patients.

The "Bankart knee": high-grade impression fractures of the posterolateral tibial plateau lead to increased translational and anterolateral rotational instability of the ACL-deficient knee

PURPOSE

The aim of this biomechanical cadaver study was to evaluate the effects of high-grade posterolateral tibia plateau fractures on the kinematics of anterior cruciate ligament (ACL)-deficient joints; it was hypothesized that, owing to the loss of the integrity of the osseous support of the posterior horn of the lateral meniscus (PHLM), these fractures would influence the biomechanical function of the lateral meniscus (LM) and consequently lead to an increase in anterior translational and anterolateral rotational (ALR) instability.

METHODS

Eight fresh-frozen cadaveric knees were tested using a six-degree-of-freedom robotic setup (KR 125, KUKA Robotics, Germany) with an attached optical tracking system (Optotrack Certus Motion Capture, Northern Digital, Canada). After the passive path from 0 to 90° was established, a simulated Lachman test and pivot-shift test as well as external rotation (ER) and internal rotation (IR) were applied at 0°, 30°, 60° and 90° of flexion under constant 200 N axial loading. All of the parameters were initially tested in the intact and ACL-deficient states, followed by two different types of posterolateral impression fractures. The dislocation height was 10 mm, and the width was 15 mm in both groups. The intraarticular depth of the fracture corresponded to half of the width of the posterior horn of the lateral meniscus in the first group (Bankart 1) and 100% of the meniscus width in the second group (Bankart 2).

RESULTS

There was a significant decrease in knee stability after both types of posterolateral tibial plateau fractures in the ACL-deficient specimens, with increased anterior translation in the simulated Lachman test at 0° and 30° of knee flexion (p = 0.012). The same effect was seen with regard to the simulated pivot-shift test and IR of the tibia (p = 0.0002). In the ER and posterior drawer tests, ACL deficiency and concomitant fractures did not influence knee kinematics (n.s.).

CONCLUSION

This study demonstrates that high-grade impression fractures of the posterolateral aspect of the tibial plateau increase the instability of ACL-deficient knees and result in an increase in translational and anterolateral rotational instability.

In situ repair of segmental loss posterior lateral meniscal root tears outperforms meniscofemoral ligament imbrication in the ACL reconstructed knee

PURPOSE

The purpose of this study was to compare the biomechanical effect of in-situ repair of posterior lateral meniscal root (PLMR) tear with segmental meniscal loss, with and without meniscofemoral ligament (MFL) imbrication, on anterior cruciate ligament (ACL) graft force and knee joint kinematics.

METHODS

Ten fresh-frozen cadaveric knee specimens underwent kinematic evaluation in five states: 1) Native, 2) ACLR, 3) Segmental PLMR loss, 4) In-situ PLMR repair, and 5) MFL augmentation. Kinematic evaluation consisted of five tests, each performed at full extension and at 30° of flexion: 1) Anterior drawer, 2) Internal Rotation, 3) External Rotation, 4) Varus, and 5) Valgus. Additionally, a simulated pivot shift test was performed. Knee kinematics and ACL graft force were measured.

RESULTS

PLMR tear did not significantly increase ACL graft force in any test. However, PLMR repair significantly reduced ACL graft force compared to the ACLR alone (over constraint -26.6 N, p = 0.001). PLMR tear significantly increased ATT during the pivot shift test (+ 2.7 mm, p = 0.0001), and PLMR repair restored native laxity. MFL augmentation did not improve the mechanics.

CONCLUSIONS

In-situ PLMR repair eliminated pivot shift laxity through ATT and reduced force on the ACL graft, indicating that this procedure may be ACL graft-protective. MFL augmentation was not shown to have any effect on graft force or knee kinematics and untreated PLMR tears may place an ACL graft at higher risk. This study suggests concomitant repair to minimize additional forces on the ACL graft.

Consensus statement on data to be entered in the ACL tear registry: SFA-DataLake

INTRODUCTION

Anterior cruciate ligament (ACL) reconstruction is a frequent procedure, with room for improvement by rehabilitation measures and associated peripheral and meniscal surgeries that are currently under assessment, requiring follow-up. Outside France, there have been ACL registries for 20 years now. The French Arthroscopy Society (SFA) decided to set up an ACL tear registry within its SFA DataLake registry platform.

MATERIAL AND METHOD

This article presents the methodology underlying the ACL Tear Registry: i.e., identification, definition and coding of essential and relevant data. A test phase comprised an initial assessment to improve data quality and overall coherence, to optimize data-entry time for patients and practitioners, who are the guarantors of the registry's use and efficacy.

RESULTS

The SFA DataLake ACL Tear Registry was made available to SFA members in December 2021. It aims to enable a review of practices for surgeons, early detection of failure of procedures and implants, with rates of failure and abnormal complications, and identification of prognostic factors for outcome, especially regarding original items that do not figure in previous registries.

CONCLUSION

SFA DataLake strikes a balance between "indispensable" and "original" items. The choice of contents and data quality is founded on a robust methodology with overall coherence, enabling analysis of large cohorts and comparisons with the literature and other registries. However, it remains to assess rates of data entry and item relevance as the Registry progresses.

LEVEL OF EVIDENCE

IV.

Anterior Tibial Subluxation of Lateral Compartment Is Associated With High-Grade Rotatory Instability for Acute But Not Chronic Anterior Cruciate Ligament Injuries: An Magnetic Resonance Imaging Case-Control Study

PURPOSE

To investigate whether anterior tibial subluxation obtained from magnetic resonance imaging (MRI) could be a predictor of high-grade rotatory instability for anterior cruciate ligament (ACL) injuries, including acute and chronic cases.

METHODS

From September 2016 to August 2018, we retrospectively investigated 163 patients with ACL injuries who subsequently underwent primary ACL reconstruction. Among them, 30 patients with high-grade rotatory instability (grade II/III pivot shift) were included in the high-grade group, and their age and sex were matched 1:2 to low-grade cases (<grade II pivot shift). On preoperative MRI, we measured anterior tibial subluxation, posterior tibial slope, as well as the time from injury to surgery. Meniscal lesions were documented from arthroscopy. Multivariable logistic regression was used to determine predictors of high-grade rotatory instability. Furthermore, subgroup comparisons between 2 groups were divided into acute (≤3 months) and chronic (>3 months) phases.

RESULTS

The high-grade group had a larger anterior tibial subluxation of lateral compartment (8.1 mm vs 5.9 mm; P =.004) than the low-grade group, whereas no significant difference was found in anterior tibial subluxation of medial compartment (P > .05). Moreover, high-grade anterior tibial subluxation of lateral compartment (≥6 mm) was found to be an independent predictor (odds ratio, 12.992; P = .011) associated with concomitant meniscal tears after ACL injuries. Anterior tibial subluxation of lateral compartment demonstrated statistical significance between the two groups when comparing subgroups within 3 months but not beyond 3 months.

CONCLUSION

In ACL-injured patients, high-grade anterior tibial subluxation of lateral compartment (≥6 mm) could be a unique predictor of high-grade knee rotatory instability for acute but not chronic injuries. Prolonged time from injury to surgery and lateral meniscus tears were risk factors for high-grade rotatory laxity in chronic patients.

LEVEL OF EVIDENCE

Level III, retrospective prognostic trial.

Intrameniscal degeneration and meniscotibial ligament loosening are associated factors with meniscal extrusion of symptomatic discoid lateral meniscus

PURPOSE

This study aimed to compare the amount of extrusion of the discoid lateral meniscus (DLM), which was symptomatic and required surgery, with normal meniscuses and asymptomatic DLMs and examine factors associated with the extrusion of symptomatic DLM.

METHODS

Medical records of participants with DLM or normal lateral meniscus (LM) were retrospectively reviewed using magnetic resonance imaging (MRI). DLM cases were divided into symptomatic and asymptomatic groups. The midbody meniscal extrusion was measured using mid-coronal MRI. The association between meniscal extrusion and MRI findings, including the meniscofemoral ligament, meniscotibial ligament (MTL), intrameniscal signal intensity of the peripheral rim, meniscal shift, and skeletal maturity, was evaluated.

RESULTS

Eighty-six knees with DLM (63 symptomatic) were included. The control group included 31 patients. The symptomatic group showed significantly greater meniscal extrusion (mean ± standard deviation symptomatic DLM: 1.0 ± 1.1 mm, asymptomatic DLM: 0.1 ± 0.4 mm, and normal LM: 0.3 ± 0.6 mm, P < 0.001) and had a significantly higher incidence of MTL loosening (P = 0.02) and intrameniscal signal (P < 0.001) than the other two groups. In the symptomatic group, multivariable linear regression analysis showed that MTL loosening [β = 1.45, 95% confidence interval (CI) 1.03-1.86, P < 0.001] and intrameniscal signal (β = 0.49, 95% CI 0.09-0.90, P = 0.002) were independent associated factors.

CONCLUSIONS

LM extrusion was significantly more common in patients with symptomatic DLM than in those with asymptomatic DLM or a normal LM. MTL loosening and intrameniscal high-signal intensity on MRI were independently associated with meniscal extrusion. These findings help explain the pathogenesis and diagnosis of symptomatic DLM.

LEVEL OF EVIDENCE

III.

Meniscal Extrusion: A Critical Analysis Review

➢

Pathologic meniscal extrusion can compromise meniscal function, leading to increased contact forces in the tibiofemoral compartment and the acceleration of osteoarthritic changes.

➢

Extrusion is typically defined as radial displacement of ≥3 mm outside the tibial border and is best diagnosed via magnetic resonance imaging, although ultrasonography has also demonstrated encouraging diagnostic utility.

➢

Surgical management of meniscal extrusion is based on the underlying etiology, the patient's symptom profile, the preexisting health of the articular surface, and the risk of future chondral injury and osteoarthritis.

Prevalence, Biomechanics, and Pathologies of the Meniscofemoral Ligaments: A Systematic Review

Purpose

To systematically review the literature to examine current understanding of the meniscofemoral ligaments (MFLs), their function, their importance in clinical management, and known anatomical variants.

Methods

A systematic review was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines using PubMed, EMBASE, and Cochrane databases. Studies were included if they reported on the biomechanical, radiographic, or arthroscopic evaluation of human MFLs, or if they reported on an anatomical variant. These were then categorized as cadaveric, radiographic, or clinical. Biomechanical, radiographic, patient-reported, and functional outcomes data were recorded.

Results

Forty-seven studies were included in the qualitative analysis, and 26 of them were included in the quantitative analysis. Of these, there were 15 cadaveric, 3 arthroscopic, and 9 radiographic studies that reported on the prevalence of MFLs. Overall, when looking at all modalities, the presence of either the anterior or posterior MFL (aMFL, pMFL) has been noted to be 70.8%, with it being the aMFL 17.4% and the pMFL 40.6%. The presence of both ligaments occurs in approximately 17.6% of individuals. Eleven reported on mean MFL length and thickness. When evaluating mean length in both men and women, the aMFL has been reported between 21.6 and 28.3 mm and the pMFL length in this population is between 23.4 and 31.2 mm. Five reported on cross-sectional area. Nine additional papers report anatomical variants.

Conclusions

This review shows that there continues to be a variable incidence of MFLs reported in the literature, but our understanding of their function continues to broaden. A growing number of anatomic and biomechanical studies have demonstrated the importance of the MFLs in supporting knee stability. Specifically, the MFLs serve an important role in protecting the lateral meniscus and augmenting the function of the posterior cruciate ligament.

Clinical Relevance

Our findings will aid the clinician in both identifying and treating pathologies of the meniscofemoral ligaments.

High prevalence of a deep lateral femoral notch sign in patients with anterior cruciate ligament (ACL) and concomitant posterior root tears of the lateral meniscus

PURPOSE

To determine the prevalence of a deep lateral femoral notch sign (LFNS) in magnetic resonance imaging (MRI) in patients with anterior cruciate ligament (ACL) and concomitant posterior root tears of the lateral meniscus (PLRT).

METHODS

A retrospective chart review was conducted to identify all patients undergoing ACL reconstruction between 2016 and 2018. Based on the arthroscopic appearance of the lateral meniscus, patients were assorted to one of three groups: isolated ACL tear (ACL-Group), ACL tear with concomitant lateral meniscus tear not involving the posterolateral root (Meniscus-Group), and ACL tear with concomitant PLRT (PLRT-Group). Incidence and depth of a LFNS on preoperative MRI was compared between the three cohorts.

RESULTS

115 patients (mean age: 29.5 ± 11.3 years) were included in the study, with 58 patients (50.4%) assorted to the ACL-Group, 24 patients (20.9%) to the Meniscus-Group, and 33 patients (28.7%) to the PLRT-Group. The prevalence of a LFNS was significantly higher in the PLRT-Group (39.4%), when compared to the ACL- (5.2%) or Meniscus-Groups (25.0%; p < 0.001, respectively). Additionally, logistic regression analysis demonstrated that patients with PLRT were 5.3 times more likely to have a LFNS as compared to those without a lateral root tear (p < 0.001).

CONCLUSION

In patients with ACL tears, the presence of a LFNS on preoperative MRI may be predictive for a PLRT. As the LFNS occurs in almost 40% of the patients with combined ACL tears and PLRT, the LFNS may be a useful secondary diagnostic finding in early MRI diagnostic. Identifying PLRT on MRI is clinically relevant, as it prevents misdiagnosis and facilitates surgical decision-making, thus avoiding subsequent delayed treatment.

LEVEL OF EVIDENCE

Level IV.

The aspiration test: an arthroscopic sign of lateral meniscus posterior horn instability

The suspensory mechanism of the posterior horn of the lateral meniscus (PHLM) is an anatomically complex structure including the popliteomeniscal fascicles, the meniscotibial posterior root attachment and the meniscofemoral ligaments. Damage to one or several of these structures – either through knee trauma or congenital abnormalities—can result in an instability of the PHLM that may lead to lateral knee pain, locking sensations or lack of rotational control of the knee (e.g. after anterior cruciate ligament injuries). The diagnosis of PHLM instability is complex due to the lack of reliable clinical tests and imaging signs. Direct visual dynamic inspection via arthroscopy thus remains the gold standard. However, arthroscopic probing of the PHLM is not always reliable and the precise quantification of the amount of subluxation of the PHLM can be difficult. Therefore, the main objective of this report was to describe a quick and easy arthroscopic screening test called “the aspiration test” in order to help surgeons to detect PHLM instability. During the exploration of the lateral tibiofemoral compartment with the knee kept in the figure of 4 position, the arthroscope is placed in the antero-lateral portal and directed towards the lateral tibiofemoral compartment. The aspiration test is then performed by activating the aspiration of the 4-mm shaver when located in the intercondylar notch. In case of a PHLM instability, an excessive displacement of the PHLM is observed. After repair, a second aspiration test allows to verify that the PHLM has been stabilized.