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Journal of ISAKOS : Joint Disorders &... Jan 2021The discoid meniscus is a congenital morphological abnormality encountered far more commonly on the lateral than the medial side. The discoid lateral meniscus (DLM) is... (Review)
Review
The discoid meniscus is a congenital morphological abnormality encountered far more commonly on the lateral than the medial side. The discoid lateral meniscus (DLM) is more prevalent in Asia with an incidence of 10%-13%, than in the Western world with an incidence of 3%-5%. DLM can be bilateral in more than 80% cases. Due to its abnormal shape and size, the discoid meniscus is prone to tearing and has an impact on gait mechanics. The discoid meniscus has deranged collagen arrangement and vascularity which can have implications for healing after a repair. Patients with a DLM may or may not be symptomatic with mechanical complaints of locking, clicking, snapping or pain. Symptoms often arise due to a tear in the body of the meniscus or a peripheral detachment. Asymptomatic patients usually do not require any treatment, while symptomatic patients who do not have locking are managed conservatively. When a peripheral detachment is present, it must be stabilised while preserving the meniscus rim to allow transmission of hoop stresses. Rehabilitation after surgery is highly individualised and return to sports is possible after more than 4 months in those undergoing a repair. The functional outcomes and onset of radiographic arthritis after saucerisation and repairing a discoid meniscus are better in the long term, compared with a subtotal meniscectomy. However, there is no compelling evidence currently favouring a repair as results deteriorate with increasing follow-up. Poor prognosis is reported in patients undergoing a total meniscectomy, a higher age at presentation and valgus malalignment.
Topics: Arthroscopy; Cartilage Diseases; Female; Humans; Joint Diseases; Knee Joint; Male; Meniscectomy; Menisci, Tibial; Pain; Return to Sport; Rupture; Tibial Meniscus Injuries
PubMed: 33833041
DOI: 10.1136/jisakos-2017-000162 -
The Journal of Knee Surgery Nov 2017Partial and total meniscectomies are the most common treatments for patients with discoid lateral meniscus (DLM). We conducted this study to quantitatively assess and... (Meta-Analysis)
Meta-Analysis Review
Partial and total meniscectomies are the most common treatments for patients with discoid lateral meniscus (DLM). We conducted this study to quantitatively assess and compare the outcomes of partial and total meniscectomies for DLM. We also assessed whether the outcomes differed by the type of DLM, duration of follow-up, and age of patients. We searched PubMed, Embase, and the Cochrane database to identify relevant studies that reported outcomes, including Ikeuchi grade, the International Knee Documentation Committee (IKDC) Subjective Knee score, Lysholm score, or failure rate, in patients who underwent partial and total meniscectomies. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for dichotomous outcomes, whereas mean difference and 95% CIs were calculated for continuous outcomes. Fifteen studies met the inclusion criteria. The overall rate of excellent (E) or good (G) postoperatively was 85.5% (95% CI: 79.5-91.5%). The E or G rate of partial meniscectomy was significantly higher than that of total meniscectomy (OR= 1.97, 95% CI: 1.03-3.75, = 0.038). Besides, patients younger than 20 years had a significantly higher E or G rate than those older than 20 years. (OR = 3.12, 95% CI: 1.18-8.23, = 0.022). We also found the E or G rate tended to decrease from short- to long-term follow-up. Our systematic review and meta-analysis showed that that partial meniscectomy could achieve better outcomes compared with total meniscectomy for DLM patients.
Topics: Humans; Meniscectomy; Menisci, Tibial
PubMed: 28114702
DOI: 10.1055/s-0036-1598021 -
Clinics in Sports Medicine Jan 2020The menisci are 2 fibrocartilaginous crescents anchored via bony and ligamentous attachments to surrounding structures. Their biochemical composition and multilayered... (Review)
Review
The menisci are 2 fibrocartilaginous crescents anchored via bony and ligamentous attachments to surrounding structures. Their biochemical composition and multilayered structure make them ideal for converting compressive forces to tensile forces in addition to improving joint congruity and providing shock absorption to weight bearing. The medial meniscus maintains more attachments at both the horns and the midbody than the lateral meniscus, making it more susceptible to injury. Understanding of the gross anatomy, vascular anatomy, biochemical composition, and microstructure is key to understanding causes of meniscal pathology as well as treatment options for restoring its primary functions.
Topics: Body Water; Collagen Type I; Collagen Type II; Glycosaminoglycans; Humans; Knee Joint; Menisci, Tibial; Proprioception; Proteoglycans; Synovial Fluid; Tibial Meniscus Injuries; Weight-Bearing
PubMed: 31767101
DOI: 10.1016/j.csm.2019.08.007 -
The American Journal of Knee Surgery 1999
Review
Topics: Child; Humans; Magnetic Resonance Imaging; Menisci, Tibial; Radiography; Treatment Outcome
PubMed: 10323506
DOI: No ID Found -
Journal of ISAKOS : Joint Disorders &... Dec 2022The purpose of the current study was to measure extrusion of the intact lateral meniscus as a function of knee flexion angle and loading condition and to compare the...
PURPOSE
The purpose of the current study was to measure extrusion of the intact lateral meniscus as a function of knee flexion angle and loading condition and to compare the changes in extrusion with a posterior root tear using a robotic testing system and ultrasound.
STUDY DESIGN
Controlled laboratory study.
METHODS
Eight fresh-frozen cadaveric knees were subjected to external loading conditions (passive path position (no external load), 200 axial compression, 5-N-m internal tibial torque, 5-N-m valgus torque) at full extension, 30°, 60° and 90° of flexion using a robotic testing system. A linear array transducer was placed in the longitudinal orientation. Extrusion and kinematics data were recorded for two meniscus states: intact and posterior lateral root deficiency. Therefore, a complete radial root tear in the lateral meniscus at 10 mm from the tibial insertion was made in all 8 cadaveric knees using arthroscopy. The resultant forces in the lateral meniscus were also quantified by reproducing recorded paths after the removal of the lateral meniscus.
RESULTS
A lateral meniscus root tear resulted in a statistically significant increase (up to 250%) of extrusion for the lateral meniscus (p < 0.05) in comparison to the intact lateral meniscus for all externally applied loads. Without external load (passive path position), significant differences were also found between the intact and posterior lateral root deficient meniscus except at full extension (1.0 ± 0.7 mm vs. 1.9 ± 0.4 mm) and 30° of flexion (1.4 ± 0.5 mm vs. 1.8 ± 0.5 mm). Overall, with increasing flexion angle, lateral meniscus extrusion decreased for the intact as well as for the posterior lateral root deficient meniscus, with the lowest measurements in response to internal tibial torque at 90° of flexion (-3.3 ± 1.1 mm). Knee kinematics were similar whether intact or posterior lateral root tear (n.s.). Ultrasound measurement of lateral meniscus extrusion showed good inter-rater (0.65 [0.30-0.97]-0.71 [0.34-0.94]) and excellent intra-rater reliability (0.81 [0.43-0.99]).
CONCLUSION
Dynamic Ultrasound is a reliable diagnostic modality to measure the lateral meniscus extrusion which can be helpful in the diagnosis and quantification of lateral meniscal root tears.
LEVEL OF EVIDENCE
III.
Topics: Humans; Menisci, Tibial; Tibial Meniscus Injuries; Knee Injuries; Reproducibility of Results; Rupture; Lacerations; Cadaver
PubMed: 36182072
DOI: 10.1016/j.jisako.2022.08.001 -
The Knee Aug 2022This study aimed to explore the changes in lower limb axial alignment and knee joint function after arthroscopic partial resection of the discoid lateral meniscus. (Review)
Review
AIM
This study aimed to explore the changes in lower limb axial alignment and knee joint function after arthroscopic partial resection of the discoid lateral meniscus.
METHODS
Preoperative and postoperative full-length weight-bearing radiographs of the lower limb were obtained from a total of 161 patients with lateral menisci tears from September 2018 to September 2020 who underwent partial meniscal resection. The patients were divided into discoid meniscus group (DMG) and ordinary meniscus group (OMG). The measured mechanical axis deviation (MAD), proximal tibia angle (PTA), and distal femoral angle (DFA) in the axial alignment of the lower limb were determined before and after surgery. Knee joint function on the affected side was determined using the International Knee Documentation Committee (IKDC) subjective scale and the Lysholm knee scoring scale before surgery and at one, six, 12, and 24 months after surgery.
RESULTS
For MAD and DFA, there were statistically significant differences between the preoperative and postoperative findings within each group (P < 0.01); the MAD and DFA were smaller after surgery. The difference in preoperative and postoperative PTA of the DMG was statistically significant (P < 0.01), meaning that the PTA becomes larger after surgery. The differences in preoperative and postoperative PTA of the OMG, preoperative PTA between the two groups, and postoperative PTA between the two groups were not statistically significant (P > 0.05). Intragroup comparisons of the IKDC subjective scale and the Lysholm knee scoring scale before and after surgery revealed significant differences (P < 0.05).
CONCLUSION
Arthroscopic partial resection of the discoid lateral meniscus is a safe and effective surgical method that can significantly improve knee joint function. Although the axial arrangement of the lower limbs will be slightly changed in the early stage, it will still be within the normal range after surgery in patients with normal lower limb axial alignment. For patients with varus or valgus before surgery, this procedure should be applied with caution.
Topics: Arthroscopy; Humans; Knee Joint; Lower Extremity; Menisci, Tibial; Meniscus; Retrospective Studies; Tibial Meniscus Injuries
PubMed: 35809449
DOI: 10.1016/j.knee.2022.06.010 -
Archives of Orthopaedic and Trauma... Dec 2023The Wrisberg variant of the discoid lateral meniscus is a very rare disorder and is characterized by the hypermobility and instability of the meniscus caused by the... (Review)
Review
INTRODUCTION
The Wrisberg variant of the discoid lateral meniscus is a very rare disorder and is characterized by the hypermobility and instability of the meniscus caused by the absence of its posterior tibial attachment, with only its meniscofemoral junction (Wrisberg's ligament) maintained, and inserted in the posterior horn of the meniscus. As a result, the posterior horn of the lateral meniscus is mobile; often subluxing into the joint.
MATERIALS AND METHODS
A total of eight skeletally immature patients with symptomatic Wrisberg variant of the discoid lateral meniscus were included in this study. Each knee was evaluated with MRI and arthroscopy. We graded unstable discoid menisci according to their discoid morphology (complete vs. incomplete), meniscal intra-substance degeneration, and the presence or absence of meniscal tears. All eight menisci were evaluated as degenerated with no meniscal tears. Five of them were evaluated as complete. Due to the severely degenerated meniscus, we considered it unnecessary to repair the detached posterior tibial ligament, so we performed a reshaping of the discoid meniscus, restoring a C-shape, excising the hypertrophied central part of the meniscus, and creating a posterior horn with a remaining rim of 6-8 mm. For evaluation of the knee function preoperatively and postoperatively we used the online International Knee Documentation Committee (IKDC) system. The purpose of this study is to emphasize the importance of MRI in identifying and revealing the unstable (Wrisberg variant) type of discoid meniscus in children.
RESULTS
The mean patient age at the time of surgery was 8.25 ± 2.91 years (range 5-13 years). The average follow-up was 3.75 ± 0.46 years (range 3-4) years. The mean preoperative IKDC score was 22.37 ± 1.50 (range 21-25) points. The mean postoperative IKDC score was 80.50 ± 1.77 (range 79-84) points.
CONCLUSIONS
MRI is a valuable tool in the evaluation of the shape, stability, and consistency of symptomatic discoid menisci. It is helpful for the detection of the unstable Wrisberg variant.
Topics: Humans; Child; Child, Preschool; Adolescent; Knee Joint; Menisci, Tibial; Joint Diseases; Cartilage Diseases; Knee Injuries; Magnetic Resonance Imaging; Arthroscopy; Retrospective Studies
PubMed: 37646798
DOI: 10.1007/s00402-023-05021-7 -
Knee Surgery, Sports Traumatology,... Jan 2015To summarize and discuss the current knowledge on posterior lateral meniscus root tears. (Review)
Review
PURPOSE
To summarize and discuss the current knowledge on posterior lateral meniscus root tears.
METHODS
A comprehensive review of the MEDLINE database was carried out to identify relevant articles using different keywords (e.g. "meniscus root", "root tear", "meniscus avulsion", "radial tear" and "lateral meniscus"). The reference lists of the reviewed articles were searched for additional relevant articles.
RESULTS
Posterior lateral meniscus root tears are found in 7-12% of patients with a tear of the anterior cruciate ligament (ACL). Biomechanical studies have found an increase in lateral compartment contact pressure of approximately 50% after creation of a posterior lateral meniscus root tear. There is some evidence that the biomechanical consequences of these injuries are significantly influenced by the presence and integrity of the meniscofemoral ligaments. Clinical studies have found encouraging results after repair of posterior lateral meniscus root tears. Whether root repair can prevent the development of osteoarthritis is currently unknown.
CONCLUSION
A posterior lateral meniscus root tear is a clinical relevant but most likely underrecognized concomitant injury in patients with a tear of the ACL. This article may support clinicians in diagnosing and treating this unique type of meniscus tear.
LEVEL OF EVIDENCE
V.
Topics: Anterior Cruciate Ligament; Anterior Cruciate Ligament Injuries; Biomechanical Phenomena; Humans; Knee Injuries; Menisci, Tibial; Pressure; Rupture; Tibial Meniscus Injuries
PubMed: 24531361
DOI: 10.1007/s00167-014-2904-x -
Journal of Orthopaedic Surgery (Hong... 2023Complete meniscus root tear is associated with meniscus extrusion; this causes a loss of meniscus function and accelerated osteoarthritis of the knee. Existing... (Meta-Analysis)
Meta-Analysis Review
PURPOSE
Complete meniscus root tear is associated with meniscus extrusion; this causes a loss of meniscus function and accelerated osteoarthritis of the knee. Existing small-scale retrospective case-control studies suggested that the outcomes were different between medial and lateral meniscus root repair. This meta-analysis aims to study whether such discrepancies exist via a systematic review of the available evidence in the literature.
METHODS
Studies evaluating the outcomes of surgical repair of posterior meniscus root tears, with reassessment MRI or second-look arthroscopy, were identified through a systematic search of PubMed, Embase, and Cochrane Library. The degree of meniscus extrusion, healing status of the repaired meniscus root, and functional outcome scores after repair were the outcomes of interest.
RESULTS
Among the 732 studies identified, 20 studies were included in this systematic review. 624 knees and 122 knees underwent MMPRT and LMPRT repair, respectively. The amount of meniscus extrusion following MMPRT repair was 3.8 ± 1.7 mm, which was significantly larger than the 0.9 ± 1.2 mm observed after LMPRT repair ( < 0.001). Significantly better healing outcomes were observed on reassessment MRI after LMPRT repair ( < 0.001). The postoperative Lysholm score and IKDC score was also significantly better after LMPRT than MMPRT repair ( < 0.001).
CONCLUSIONS
LMPRT repairs resulted in significantly less meniscus extrusion, substantially better healing outcomes on MRI, and superior Lysholm/IKDC scores, when compared to MMPRT repair. This is the first meta-analysis we are aware of that systematically reviews the differences in the clinical, radiographic, and arthroscopic results of MMPRT and LMPRT repair.
Topics: Humans; Menisci, Tibial; Retrospective Studies; Knee Joint; Osteoarthritis; Magnetic Resonance Imaging; Arthroscopy; Rupture
PubMed: 37173149
DOI: 10.1177/10225536231175233 -
Current Opinion in Pediatrics Feb 2002The discoid meniscus is the most common abnormal meniscal variant in children. It is most likely a congenital deviation and usually occurs laterally. The discoid shape... (Review)
Review
The discoid meniscus is the most common abnormal meniscal variant in children. It is most likely a congenital deviation and usually occurs laterally. The discoid shape results in greater coverage of the tibia and usually is associated with increased thickness of the meniscus that may lead to abnormal shearing forces across the knee joint. The Watanabe classification divides this anomaly into three distinct types: complete, incomplete, and Wrisberg ligament. The complete and incomplete types are often asymptomatic; unless symptomatic, they generally should be left alone. Tears should be treated with resection back to a stable rim. The Wrisberg ligament type is a hypermobile meniscus secondary to a lack of posterior tibial attachment. This type may or may not be associated with an abnormal shape and may appear in childhood as a classic snapping knee syndrome. These children complain of intermittent popping and snapping within the knee that clinically manifests as a dramatic audible and visible adjustment of the knee with each flexion and extension. Treatment of a symptomatic Wrisberg ligament type requires surgical repair of the posterior disruption. Saucerization of the remaining meniscus may be required to protect the repair from abnormal shear forces.
Topics: Child; Humans; Magnetic Resonance Imaging; Menisci, Tibial; Musculoskeletal Abnormalities
PubMed: 11880735
DOI: 10.1097/00008480-200202000-00010