Tears of the Popliteomeniscal Fascicles of the Lateral Meniscus: An Arthroscopic Classification

Hypermobile lateral meniscus: A systematic review of current treatment options

PURPOSE

The reliable data on the incidence of hypermobile lateral meniscus (HLM) and its clinical manifestations, diagnostic methods and therapeutic approaches are limited. This systematic study aimed to review available treatment options for HLM and the outcomes of each approach.

METHODS

A systematic search was performed in four electronic databases (PubMed, EMBASE, Scopus, Web of Science) to identify studies in which arthroscopically confirmed cases of HLM were treated surgically or nonsurgically, and the required data comprising study characteristics, patient data, treatment approaches and outcome measures were extracted from eligible studies.

RESULTS

Twenty studies with a total of 212 patients (138 males and 74 females) and 219 knees were included. The most frequently reported symptoms were locking sensations, knee pain, giving way and snapping. Treatments used by the studies were: radiofrequency energy in two studies; arthroscopic partial meniscectomy in one study; open surgery in two studies; and arthroscopic meniscal repair in 17 studies. Eleven studies used an all-inside repair method and an inside-out meniscal repair was reported in eight studies. Three studies reported the usage of posterior arthroscopy for therapeutic or diagnostic approaches. Evaluation of symptom resolution was the main outcome measurement for which almost all of the studies stated relief of symptoms after intervention.

CONCLUSION

Despite the lack of definite consensus about the most appropriate intervention for HLM, therapeutic preference was directed towards arthroscopic all-inside and inside-out repair techniques. Although the surgeon's decision remains the key factor in choosing the most suitable treatment option for each individual, posterior arthroscopic meniscal repair may be considered as a better option for HLM treatment according to the findings of this review.

LEVEL OF EVIDENCE

Level IV.

[Application of anterior region suture of popliteal hiatus in treatment of discoid lateral meniscus injury with instability in popliteal tendon region]

Objective

To discuss the application of anterior region suture of the popliteal hiatus (PH) under arthroscopy in the treatment of discoid lateral meniscus (DLM) injury with instability in the popliteal tendon region.

Methods

The clinical data of 53 patients (56 knees) with DLM injury who met the selection criteria between March 2014 and November 2022 were retrospectively analyzed. There were 15 males and 38 females, aged 8-55 years with an average age of 36.5 years. Fourteen cases had a history of trauma, while the remaining 39 cases had no clear history of trauma. The disease duration ranged from 1 day to 6 years, with an average duration of 15.6 months. According to the Watanabe classification, there were 40 knees of complete type and 16 knees of incomplete type. The preoperative International Knee Documentation Committee (IKDC) knee joint score was 51.2±8.3, the Lysholm score was 59.6±11.2, and the visual analogue scale (VAS) score was 4.7±1.3. After the arthroscopic meniscal plasty, the instability of the popliteal tendon region meniscus was checked by probing traction. Subsequently, the Out-inside technique or a combination of Out-inside and All-inside techniques was used to suture the anterior region of the PH. The stability of the meniscus after suturing was assessed, and if necessary, further suturing using the All-inside technique at the posterior region of the PH, the posterior horn of the meniscus, and using the Out-inside technique at the anterior horn of the meniscus was performed. Postoperative complications were recorded. The effectiveness was evaluated using pre- and post-operative IKDC scores, Lysholm scores, and VAS scores.

Results

After operation, knee joint pain, crepitus, and locking disappeared, with McMurray and grinding tests turning negative. All patients were followed up 12-93 months with an average of 57.5 months. There was no complication such as common peroneal nerve injury, deep vein thrombosis of the lower limbs, joint infection, or joint stiffness. At last follow-up, the IKDC knee joint score was 76.7±5.5, the Lysholm score was 94.0±4.1, and the VAS score was 1.1±0.8. The differences compared with preoperative scores were significant ( t=-22.090, P<0.001; t=-23.704, P<0.001; t=19.767, P<0.001).

Conclusion

Suturing of the anterior region of the PH is crucial in the treatment of DLM injury with instability in the popliteal tendon region.

Surgical treatment of popliteomeniscal fascicles tears is associated with better patient-reported outcome measures. A systematic review and meta-analysis

PURPOSE

Popliteomeniscal fascicles (PMFs) are a component of the popliteal hiatus complex in the knee, and their injury primarily affects young athletes participating in sports activities involving twisting movements. The identification of PMFs tears presents a challenge, often accompanied by lateral pain and a locking sensation. The objective of this systematic review (SR) and meta-analysis is to enhance the suspicion and recognition of PMFs tears, aiming to facilitate the treatment of this condition, particularly in symptomatic young patients.

METHODS

A comprehensive search, focused on studies examining PMFs injuries and their treatment, was conducted in four databases, PubMed, Scopus, Embase, and Web of Science. The ROBINS-I tool was used to evaluate the risks of bias. The PRISMA flow diagram was used to conduct the research and select the included studies. A meta-analysis was conducted for the Lysholm score, the Tegner Activity Scale, and the subjective IKDC score. The present SR and meta-analysis was registered on PROSPERO.

RESULTS

Five clinical studies were included in the final analysis, comprising 96 patients. All the patients underwent a preoperative MRI assessment and a diagnostic arthroscopy to detect the PMFs tears, with a subsequent surgical procedure either open or arthroscopically performed. Surgery was associated with the resolution of symptoms. A statistically significant improvement in the Lysholm score (p: 0.0005) and the subjective IKDC score (p: 0.003) after the surgical procedure with respect to the preoperative evaluation was found.

CONCLUSION

This SR and meta-analysis showed a significant improvement in the Lysholm score and subjective IKDC score following surgery for PMFs tears. However, controversy persists regarding the optimal surgical approach, with current literature favoring arthroscopic procedures.

LEVEL OF EVIDENCE

IV.

Clinical presentation and arthroscopic treatment of hypermobile Type III Wrisberg variant of lateral discoid meniscus: Report of nine cases

BACKGROUND

The aim of the present study was to document a series of patients with meniscal hypermobility due to a Type III Wrisberg variant lateral discoid meniscus, describing their clinical presentation, analyzing their magnetic resonance imaging (MRI) and arthroscopic characteristics, and reporting the outcomes of an all-inside stabilization.

METHOD

Nine cases of Wrisberg variant Type III discoid lateral menisci were identified based on patient's history and clinical examination. Knee MRIs were reviewed to exclude the presence of Type I-II discoid meniscus (complete or incomplete) or bucket handle tears and general arthroscopic criteria. For the Wrisberg variant discoid lateral meniscus were applied for the final diagnosis.

RESULTS

All nine cases presented similar peculiar clinical, radiological, and arthroscopic features, which led to the diagnosis of hypermobile Wrisberg variant of lateral discoid meniscus. This rareclinical entity is responsible for suggestive symptoms such as pain, popping and knee locking; moreover, subtle but peculiar MRI and arthroscopic characteristics can be observed.

CONCLUSION

Considering the possibility of repeated dislocation and relocation, diagnosis can be challenging, and a high degree of suspicion should be used, especially in young patients, bilateral symptoms, and absence of trauma.

The Posteromedial-Transseptal Portal for Arthroscopic Suture Hook Repair of Posterior Horn Tears and Popliteomeniscal Fascicles Tears of the Lateral Meniscus

We present a convenient and safe arthroscopic technique for suturing the lateral meniscus. In this technique, the clinician establishes a conventional posteromedial approach in the figure-of-four position of the knee by using the anterolateral and anteromedial observation approaches. Behind the posterior cruciate ligament, an operational approach is formed through the posterior mediastinum of the knee joint. Through this approach, suture hook can be brought to the posterior horn and body of the lateral meniscus, thus simplifying the suture of the lateral meniscus. We have used this technique to finish all-inside suture using suture hooks in a variety of types of lateral meniscal injuries, including longitudinal posterior horn tears, bucket handle meniscus tears, and tears around the popliteal hiatus area. Compared with traditional lateral meniscal all-inside suture technology through anteromedial or anterolateral approaches, this technology can suture more accurately, safely, and conveniently, avoid the involvement of the popliteal tendon suture, and the lower risk of complications such as popliteal vascular and nerve injury occur.

[A study on repair method of type c injury in lateral meniscus popliteal tendon area of porcine knee]

Objective

To investigate the repair method of type Ⅱc injury in the lateral meniscus popliteal tendon area based on the porcine knee joint.

Methods

Eighteen commercially available fresh porcine knee joints were randomly divided into 3 groups ( n=6). After preparing a type Ⅱc injury in the lateral meniscus popliteal tendon area, and the anterior (group A), posterior (group B), or anterior and posterior (group C) of the popliteal hiatus (PH) was sutured by vertical mattress. The tension meter was used to apply gradient tensions of 2, 4, 6, 8, and 10 N along the tibial plateau horizontally, respectively, to pull the midpoint of the lateral meniscus popliteal tendon area. The displacement values before modeling, after modeling, and after suture were recorded. The reduction value of lateral meniscus displacement and reduction rate after suture were calculated and compared between groups.

Results

There was no significant difference between groups ( P>0.05) in the displacement values before modeling, after modeling, and after suture under different tensions. There was no significant difference between groups A and C ( P>0.05) in the reduction value of lateral meniscus displacement and reduction rate after suture under different tensions. The reduction value of lateral meniscus displacement and reduction rate after suture in group B were lower than those in groups A and C. The reduction value of lateral meniscus displacement under tension of 2 N and the reduction rates under tensions of 2, 4, and 6 N between groups A and B showed significant differences ( P<0.05). The reduction value of lateral meniscus displacement and the reduction rate under tensions of 2, 4, and 6 N between groups B and C showed significant differences ( P<0.05).

Conclusion

Suturing the anterior area of PH is the key to repairing type Ⅱc injury of lateral meniscus popliteal tendon area.

Lateral Meniscal Root Displacement into the Popliteal Hiatus in a Multiligamentous Knee Injury: A Case Report

CASE

A 45-year-old female patient presented with left knee pain after a ski accident. Magnetic Resonance Imaging (MRI) showed complete rupture of the anterior cruciate ligament, posterior cruciate ligament, proximal Medial Collateral Ligament (MCL), and medial patellofemoral ligament. The lateral meniscal root was torn with the posterior horn incarcerated superiorly into the popliteal hiatus, rendering high risk of plastic deformation. An unconventional 2-staged surgical approach was performed.

CONCLUSION

Where risk of meniscal plastic deformation is high in the setting of multiligamentous knee injury (MLKI), diagnosis and careful surgical planning are central to a successful outcome. Treatment of intra-articular structures in operative stage 1 in MLKI is possible and was necessary in this case.

Single Needle All-Inside Technique for Lateral Meniscus Repair at Popliteal Hiatus Area: Safe, Effective, and Time-Saving

The lateral meniscus tear at the popliteal hiatus area is a tricky problem in clinical treatment due to the difficulty of preoperative diagnosis, narrow space for operation, lack of capsular attachments, and risk of vascular injuries. This article introduces an arthroscopic single-needle, all-inside technique suitable for repairing longitudinal and horizontal lateral meniscus tears at the popliteus tendon hiatus area. We believe this technique is safe, effective, economical and reproducible.

The hypermobile and unstable lateral meniscus: a narrative review of the anatomy, biomechanics, diagnosis and treatment options

Objective

The purpose of this review is to improve the awareness of lateral meniscal hypermobility by describing its relevant anatomy, biomechanics, pathophysiology, imaging and arthroscopic findings as well as the treatment options.

Background

The lateral meniscus is less stable than the medial meniscus. Its important posterior stabilizers are the popliteomeniscal fascicles, the posterior capsule, the meniscofemoral ligaments and the posterior meniscotibial ligament, which are divided by a bare area, the popliteal hiatus. Atraumatic insufficiency or rupture of one of these key structures may impact the mobility of the lateral meniscus and can lead to an unstable, hypermobile lateral meniscus. Lateral meniscus hypermobility can cause lateral knee pain and mechanical symptoms as locking. Ruptures of the popliteomeniscal fascicles are frequently associated with anterior cruciate ligament and posterolateral corner injuries. Their repair may be important to fully restore knee stability.

Methods

This is a narrative overview of the literature synthesizing current knowledge about the hypermobile lateral meniscus. Anatomy, biomechanics, diagnosis and treatment of this entity was of particular interest for this review. Literature was retrieved from PubMed database, hand searches and cross-reference checking.

Conclusions

Diagnosing lateral meniscus hypermobility is challenging since the magnetic resonance imaging are often unspecific and may show no structural alterations of the meniscus and its attachments. The only hint can be the patient's history and clinical symptoms (e.g., locking). Ultimately, the diagnosis is confirmed during knee arthroscopy, when the lateral meniscus can be mobilized over 50% of the lateral tibial plateau or lateral femoral condyle while anterior probing or by using the aspiration function during arthroscopy. Treatment includes stabilizing the posterior lateral meniscus by repairing the injured structures. Therefore, a systematic arthroscopic evaluation of the lateral compartment is important to fully recognize the problem. Repair can be achieved arthroscopically with various suturing techniques used for meniscal repair with satisfactory results and low recurrence rates.

Preoperative Magnetic Resonance Imaging as a Diagnostic Aid for Hypermobile Lateral Meniscus

Background: Hypermobile lateral meniscus is difficult to diagnose with imaging due to its absence of tears or anomalies. We aimed to clarify the accuracy of the preoperative diagnosis using magnetic resonance imaging (MRI). Methods: The preoperative MRI status of the posterosuperior popliteomeniscal fascicle (sPMF), anteroinferior popliteomeniscal fascicle (iPMF), and popliteal hiatus were examined retrospectively on sagittal images in the hypermobile lateral meniscus group (n = 22) and an age- and gender-matched control group (n = 44). These statuses were evaluated by a logistic regression analysis to assess their degree of diagnostic accuracy. Results: The area under the curve (AUC) of the sPMF, iPMF, popliteal hiatus, and all three criteria combined was 0.66, 0.74, 0.64, and 0.77, respectively (low, moderate, low, and moderate accuracy, respectively). The odds ratios of the most severe type 3 forms of the sPMF, iPMF, and popliteal hiatus for hypermobile lateral meniscus were significantly high (5.50, 12.20, and 5.00, respectively). Although the diagnostic accuracy was not high enough, the significantly higher odds ratio for type 3 may indicate a hypermobile lateral meniscus. Conclusion: a definitive diagnosis of hypermobile lateral meniscus is difficult with MRI findings alone; however, MRI evaluations of the iPMF, sPMF, and the widening of popliteal hiatus can be used as an adjunct to diagnosis.