Symptomatic Discoid Lateral Meniscus Research Articles

Arthroscopic Partial Meniscectomy in Adult Patient with Symptomatic Discoid Lateral Meniscus: A Case Report

Introduction: For many years, the discoid meniscus was synonymous with snapping knee syndrome. incidence of discoid lateral meniscus is estimated to be 0.4% to 17%, whereas the discoid medial meniscus is extremely rare (0.1% to 0.3%). It has been reported that about 20% of cases are bilateral. Patients with discoid lateral meniscus (DLM) often show normal plain radiography findings but may also show subtle indirect signs. Case Presentation: Female, 59 years old, complained of pain on her left knee after walking and climbing stairs for the last two months. On examination, the range of motion of knee joint was limited due to the pain for flexion more than 90°. Patient had medial joint line tenderness, and a McMurray test elicited pain on the lateral joint line. Radiographs of the left knee showed lateral joint space widening and high fibular head. Arthroscopic examination of the left knee confirmed the presence of discoid lateral menisci (DLM). Discussion: Discoid lateral meniscus (DLM), often referred to as "popping knee syndrome," is an abnormal variation of the meniscus, primarily affecting the lateral side and more common in young individuals. This condition increases the risk of knee injury, especially if the ligament attachment to the tibia is absent. In our case, radiographic findings and a positive McMurray test led to the diagnosis, confirmed by arthroscopy showing a complete DLM. While some recommend for total meniscectomy, studies suggest that partial meniscectomy can offer good initial results, though long-term outcomes may vary. Conclusion: In symptomatic DLM, surgical treatment is necessary to treat the patient. Arthroscopic partial meniscectomy is the preferred surgical procedure to treat symptomatic DLM. Keywords: Discoid lateral meniscus, arthroscopic menisectomy, WOMAC score

Characteristics and Outcomes of Operatively Treated Discoid Lateral Meniscus in Pediatric and Young Adult Patients: A Multicenter Study.

Discoid lateral meniscus (DLM) is the most common congenital abnormality of the meniscus. Tears are common; treatment is frequently not definitive, often requiring reoperation. To report the clinical manifestations, physical characteristics, operative treatments and findings, complications, and reoperations of DLM in pediatric patients from multiple centers across North America. Case series; Level of evidence, 4. Consecutive patients who underwent treatment for symptomatic DLM at 9 institutions between 2000 and 2020 were included. Patient data, presenting symptoms and signs, surgical findings, treatments rendered, and postoperative complications, including reoperation rates, were collected. Means with ranges and counts with proportions are reported for continuous and categorical variables, respectively, and comparisons were made using either the chi-square or Fisher exact test. In total, 784 patients (867 knees) were included with a mean age at diagnosis of 12 years (range, 1-22 years) and a mean follow-up of 22.6 months (range, 0-154 months). Common preoperative symptoms were locking (33%) and snapping (30%). At surgery, tears in the DLM were present in 647 knees (594 patients [76%]); 95 knees (11%) had multiple tears; and in 140 knees, tears extended into >1 zone. Tears, when present, were more common within the posterior horn (41%) or body (34%) than the anterior horn (25%). Peripheral rim instability was reported in 241 knees (28%). Significantly more knees had instability posteriorly (15%; P = .0004) and anteriorly (9%; P = .0013) than along the body (3%). Tear type was most commonly complex (38%) or horizontal (34%). A total of 358 knees in 333 patients with tears (42% of all patients) underwent repair (55% of knees with tears). A total of 175 complications were reported, occurring in 139 knees in 134 patients (17%); 116 of these knees with complications (83%) had a single complication, while 23 (17%) had >1. Of the 784 patients, 105 (13%) underwent reoperation, undergoing 135 additional procedures related to their DLM. Of those, 60 (44%) were repeat arthroscopy and meniscal trim; 40 (30%), arthroscopy and meniscal repair; and 17 (13%), an articular cartilage procedure. Locking and snapping were common presenting symptoms. Over three-quarters of patients had meniscal tears, which were most often complex and located posteriorly. Seventeen percent of patients experienced complications, and a sixth of patients with complications had >1. Reoperation was typically for persistent symptoms or meniscal retear.

Younger age is a risk factor for developing recurrent or postoperative osteochondritis dissecans after surgery for discoid lateral meniscus with/without preoperative osteochondritis dissecans.

To evaluate the efficacy of surgical treatment of the discoid lateral meniscus with osteochondritis dissecans (OCD) through clinical and radiological evaluations, focusing on recurrent or postoperative OCD occurrence. This retrospective study included patients with symptomatic discoid lateral meniscus with OCD (pre-OCD group) and without OCD (non-OCD group) who had undergone arthroscopic surgery with >5 years of follow-up. Age, sex, Lysholm score, Tegner activity scale, surgical procedure, and recurrent or postoperative OCD lesions were compared. The association between patient variables and postoperative OCD was determined using multivariate logistic regression analysis. Of the 95 knees, 15 (15%) were in the pre-OCD group. Healing was observed in 14/15 (93%) knees. Recurrent and postoperative OCDs were reported in 4/15 (28.5%) knees in the pre-OCD and 7/80 (8.8%) knees in the non-OCD groups at a mean of 3.2 ± 1.1 and 3.7 ± 1.2 years, respectively. Pre- and postoperative Tegner activity scale and Lysholm scores were higher in the pre-OCD group but similar to those in the non-OCD group. The incidence of recurrent OCD in the pre-OCD group was significantly higher than that of postoperative OCD in the non-OCD group. Younger patients (odds ratio, 0.49; p = 0.003) had an increased risk of experiencing recurrent or postoperative OCD in multivariate analysis. The optimal cutoff age for distinguishing recurrent or postoperative OCD was 9 years. Surgical procedures for OCD lesions in the pre-OCD group were successful. Multivariate analysis identified age as a risk factor for recurrent or postoperative OCD; therefore, conservative treatment is recommended for patients with discoid lateral meniscus before preadolescence to prevent postoperative OCD occurrence. Level III.

Clinical efficacy and pain follow-up after arthroscopic discoid meniscoplasty of the knee: a retrospective study

BackgroundTo assess the viability and efficiency of performing arthroscopic meniscoplasty in treating discoid meniscus (DM) in the knee joint.MethodsA total of 29 patients diagnosed with symptomatic lateral DM between October 2014 and December 2019 were included in the study. Among them, 7 patients with intact DM underwent arthroscopic discoid meniscoplasty (group A), while 22 patients with torn DM received arthroscopic DM plasty along with repair and suturing (group B). Both Visual Analog Scale (VAS) score and Lysholm score assessments were conducted preoperatively and postoperatively.ResultThe favorable and acceptable outcome rate was 85.71% in group A and 95.45% in group B (P > 0.05). The VAS scores post-operatively at each follow-up time point were consistently lower compared to pre-operative values, while the Lysholm knee function scores showed improvement. There were no significant differences in VAS score and Lysholm score between group A and group B at different stages (P > 0.05). Both surgical techniques (discoid meniscoplasty and discoid meniscoplasty combined with repair and suture) showed significant improvement in postoperative VAS score and Lysholm score, but there was no difference in outcomes between the two groups.ConclusionOverall, the two surgical techniques studied in this study (discoid meniscoplasty and discoid meniscoplasty combined with repair and suture) produced similar results in terms of pain reduction and improved knee function.

Discoid Meniscus – A Review of Literature and Our Case Series

Abstract Aim: The current study aims at the surgical outcome of the lateral discoid meniscus which is treated with knee arthroscopy, meniscal refashioning, and meniscal repair in various age groups. Materials and Methods: The study includes 7 patients (3 females and 4 males) with a mean age of 26.6 (Range 10 to 50 years). This is a retrospective type of study with a study period ranging from June 2018 to January 2024. Results: Patient satisfaction was excellent in all cases regarding pain, locking of the knee, Range of motion, and return to sports/daily activities. Diagnostic Arthroscopy confirmed the discoid meniscus abnormality in all the cases. Bucket handle type tear of the lateral menisci in 2 cases. Anterior horn tear in 1 case. Horizontal tear in 1 case. Unstable discoid meniscus in 3 cases. Meniscoplasty, removal of central part of meniscus, and sparing its periphery was done for all cases. Stabilization of the meniscus was done with meniscal repair in 4 patients with inside-out and all inside techniques. Visual analog score (VAS score) has significantly reduced from moderate pain (45-74)and mild pain (5-44 mm)to no pain (0-4 mm). Conclusion: Arthroscopic sauscerization, meniscoplasty alone, or additional stabilization with meniscal repair can provide excellent clinical outcomes in patients with symptomatic lateral discoid meniscus.

Age and medial compartmental OA were important predictors of the lateral compartmental OA in the discoid lateral meniscus: Analysis using machine learning approach.

The objective of this study was to develop a machine learning model that would predict lateral compartment osteoarthritis (OA) in the discoid lateral meniscus (DLM), from which to then identify factors contributing to lateral compartment OA, with a key focus on the patient's age. Data were collected from 611 patients with symptomatic DLM diagnosed using magnetic resonance imaging between April 2003 and May 2022. Twenty features, including demographic, clinicaland radiological dataand six algorithms were used to develop the predictive machine learning models. Shapley additive explanation (SHAP) analysis was performed on the best model, in addition to subgroup analyses according to age. Extreme gradient boosting classifierwas identified as the best prediction model, with an area under the receiver operating characteristic curve (AUROC) of 0.968, the highest among all the models, regardless of age (AUROC of 0.977 in young age and AUROC of 0.937 in old age). In the SHAP analysis, the most predictive feature was age, followed by the presence of medial compartment OA. In the subgroup analysis, the most predictive feature was age in young age, whereas the most predictive feature was the presence of medial compartment OA in old age. The machine learning model developed in this study showed a high predictive performance with regard to predicting lateral compartment OA of the DLM. Age was identified as the most important factor, followed by medial compartment OA. In subgroup analysis, medial compartmental OA was found to be the most important factor in the older age group, whereas age remained the most important factor in the younger age group. These findings provide insights that may prove useful for the establishment of strategies for the treatment of patients with symptomatic DLM. Level III.

Asymmetric Deficit of Knee Flexion: An Occasional Symptom of Discoid Lateral Meniscus in Children.

A knee flexion deficit can be the unique symptom and sign of discoid lateral meniscus (DLM) in children. The aim of this study was to investigate the accuracy of this clinical sign. The hypothesis was that deficit of knee flexion was associated with anterior rim disinsertion and posteriorly fixed DLM. A retrospective, single-center study was conducted in a larger series of 114 operated knees for symptomatic DLM from 2007 to 2018. A focus was done on 9 knees with a deficit of knee flexion without snapping. History and clinical examination with grading of instability, preoperative magnetic resonance imaging, and arthroscopic findings were studied. Among 35 knees with DLM grade 3 of instability, 26 had an isolated extension deficit. Nine knees in 5 boys and 4 girls with a mean age of 9 years (range 6 to 12) had a flexion deficit. It was the only symptom of DLM in 6, and it was associated to extension deficit in 3. In the history, 8 knees were grade 2 (snapping knee) before evolving toward a flexion deficit. All had a complete DLM with posterocentral (n=7) or central (n=2) shift at magnetic resonance imaging analysis. All had DLM with posterior shift fixed during arthroscopic evaluation. Moreover, looking at the entire series, 1 knee was a false negative and had a full flexion despite a posterior and fixed DLM during arthroscopic evaluation. The sensitivity of asymmetrical knee flexion to predict posterior fixed DLM was 90%. An asymmetric deficit in knee flexion is highly suggestive of DLM with anterior detachment and fixed posterior meniscal shift (specificity and positive predictive value of 100%). Given this could be the only clinical sign of DLM, specific attention therefore must be paid in the assessment of knee flexion by measuring the distance between heel and bottom on both sides, especially in a knee without snapping currently but with a history of snapping (grade 3). Level III.

Comparative analysis of discoid lateral meniscus size: a distinction between symptomatic and asymptomatic cases.

This study evaluated the differences in meniscal sizes and occupancy between symptomatic and asymptomatic patients diagnosed with discoid lateral meniscus (DLM) using magnetic resonance imaging (MRI) to understand how these variations relate to the presence of symptoms and the patients' age. A retrospective review of 98 patients with DLM was conducted, excluding those with meniscal displacement. Both the width and extrusion of DLM and the percentage of the meniscus to the tibia were measured using mid-coronal and mid-sagittal MRI and compared between symptomatic and asymptomatic DLM groups. The relationships among each parameter, meniscal size, and patient age were evaluated. Symptomatic cases were divided into those with and without horizontal tears on MRI to compare the differences in meniscal morphology. A total of 92 knees from 74 patients were included. Sixty-one knees required surgical intervention for symptomatic DLM, while 31 were asymptomatic and included the contralateral side of symptomatic knees. The symptomatic group exhibited larger morphological variations than the asymptomatic group. Moreover, the sagittal meniscal ratio reduced with age in the asymptomatic group (r = - 0.54, p = 0.002) but remained constant in the symptomatic group. The symptomatic cases with horizontal tears demonstrated larger meniscal dimensions and smaller posterior capsule distances than those without tears. Symptomatic patients with DLM had larger knee morphological changes than asymptomatic ones. Age affected the meniscal occupancy in the sagittal plane only in asymptomatic patients. III.

Older age and the presence of intrameniscal signs are risk factors for nonsurgical treatment failure of symptomatic intact discoid lateral meniscus.

The treatment for symptomatic intact discoid lateral meniscus (DLM) is controversial and the long-term clinical outcome remains unknown. The purpose of this study was to analyze the overall failure rate of nonsurgical treatment for symptomatic intact DLM and identify the risk factors for nonoperative management failure. Consecutive patients who underwent nonsurgical treatment for symptomatic intact DLM at our hospital from 2014 to 2017 were retrospectively reviewed. Patients were divided into Group A (failure group) and Group B (nonfailure group) based on overall failure criteria: conversion to surgery, progression of a tear on MRI re-examination, or severely abnormal International Knee Documentation Committee (IKDC) scores. Statistical analyses between the two groups were performed for demographic and radiographic characteristics. Multivariate regression analysis was used to determine the risk factors associated with worse outcomes. One-hundred and four knees in 96 patients were included in this study. After a mean follow-up of 76.9 ± 11.1months, 25 knees (24.0%) met the overall failure criteria. Multivariate regression analysis demonstrated that age and the presence of intrameniscus signals increased the risk of nonoperative management failure. The clinical criterion of age > 37.5years combined with the imaging criterion of the presence of intrameniscal signals predicted conservative treatment failure of symptomatic intact DLM with a sensitivity of 0.87 and a specificity of 0.91. Twenty-five (24.0%) knees that underwent nonsurgical treatment met the overall failure criteria after a mean follow-up of 76.9months. With increased age and the presence of intrameniscal signals, the nonoperative results become worse. III.

Discoid lateral meniscus instability in children: partII.: Repair first to minimise the saucerisation.

Despite an improved understanding of discoid lateral meniscus (DLM), the treatment of symptomatic discoid lateral meniscus remains controversial. The aim of this retrospective, single-centred, consecutive-case study was to evaluate the clinical outcome of 60 DLM treated arthroscopically by the "meniscoplasty or saucerisation-suture" technique in children and adolescents [median (range) age 11 (4-17) years], and to investigate surgical failures. The instability was assessed before any saucerisation. The hypotheses were that: (i) the management of instability with suture first was effective and that (ii) a combined classification with clinical and MRI data had a prognostic value. In 57 knees (95%), the DLM was unstable, and a suture fixation was performed. After a median follow-up of 41.5months, the median (range) IKDC score was improved from 55 (10-70) preoperatively to 90 (37.5-100) postoperatively. The median (range) Lysholm score at last follow-up was 93.5 (45-100). The procedure was effective in 49 knees (81.6%) after a single procedure. Eleven patients had a failure with a new meniscal tear after a median (range) delay of 42months (24-60) after the initial procedure. The patterns of discoid lateral meniscus instability were not found to have a prognostic value for surgical failure since they mainly occurred after sport-related injuries. All the patients with initial repair failures but one achieved a good clinical outcome after revision repair without any further meniscectomy. In contrast to adult knees, symptomatic discoid lateral meniscus is rarely stable in children (5%). Meniscal repair is effective to preserve the meniscus tissue, but revision repair became necessary in 18% of the cases and was finally successful. Level of evidence Level III.

Arthroscopic treatment of the symptomatic discoid lateral meniscus improves the knee function in the long-term: a ten-year follow-up study.

Discoid lateral meniscus (DLM) is a common meniscal anatomic disorder and can cause irreversible knee consequences. The long-term clinical outcomes of DLM management remain unclear. Moreover, several potential factors would influence the long-term functional outcomes. The factors also remain unclear. This study aims to evaluate the long-term clinical outcomes of the arthroscopic management of the DLM and to identify the patients' factors affecting the long-term results. Medical records were retrospectively examined for patients with symptomatic unilateral DLM who underwent arthroscopic procedures between January 2004 and August 2011. The characteristics of DLM, the preoperative and the long-term postoperative visual analog scale (VAS), the International Knee Documentation Committee (IKDC) score, Lysholm, and Yulish scores were evaluated. Data were collected, processed, and analyzed using SAS software version 9.2. Univariate and multivariate analyses were performed to identify the factors influencing the long-term outcomes of the DLM arthroscopy. A total of 128 patients were included, most of whom were females (68.7%). The median age of the included participants was 24 (16-31) years old. The median duration of symptoms was 23.3 (10, 31) months, and the median follow-up duration was 126.2 (113, 140) months. The functional scores significantly improved postoperatively compared to the preoperative scores; VAS (1.65 ± 1.17 vs. 6.08 ± 1.31), Lysholm (91.39 ± 5.05 vs. 77.51 ± 10.19), and IKDC (84.63 ± 7.69 vs. 67.89 ± 9.56), respectively; p<0.05. Multivariate analysis revealed that gender, the status of self-reported instability, preoperative VAS, Yulish MR cartilage grade, and Lysholm score had a significant correlation with the worsening of the final follow-up IKDC scores. Arthroscopic procedure significantly improved the long-term joint function of the DLM patients, as evidenced by the sustained improvement of the VAS, Lysholm, and IKDC scores. These clinical outcomes were greatly influenced by gender, the status of self-reported instability, preoperative Yulish MR cartilage grade, VAS, and Lysholm score.

Saucerization of complete discoid lateral meniscus is associated with change of morphology of the lateral femoral condyle and tibial plateau.

To determine the effect of saucerization surgery on knee joint morphology associated with a complete discoid lateral meniscus (DLM) using magnetic resonance (MR) imaging. This retrospective study included cases had undergone saucerization surgery for symptomatic DLM between 2007 and 2022. All cases were divided into two by age group: < 12 (U13) and > 13 (O13). The cases in the match group were randomly selected from preoperative cases in the O13 group matched with the age at the final follow-up (F/U) of cases in the U13 group. The following morphological parameters were evaluated using MR images preoperatively and at the final postoperative F/U in each group: anterior obliquity of the lateral tibial plateau (AOLTP), posterior obliquity of the lateral tibial plateau (POLTP), and the lowest point of the lateral femoral condyle (LPLFC). Each parameter was compared between the U13 preoperative (pre-OP) group and the O13 pre-OP group, the preoperative and final follow-up in the U13, and the U13 group at the final F/U and the match group preoperatively. A total of 77 cases were evaluated. 31 cases were in the U13 pre-OP group and 46 were in the O13 pre-OP group. With a minimal F/U of 2years, 27 cases in the U13 group and 36 in the O13 group were included. The mean F/U period was 4.6years in the U13 group and 3.2years in the O13 group. 32 cases were included in the match group. In the match group, the inclination of the POLTP was significantly larger (P = 0.042) and the LPLFC was more lateral (P = 0.0034) than at the final F/U in the U13 group. Saucerization surgery for DLM in juvenile patients can prevent progression to the characteristic bone morphology DLM. These results could help the surgeon making the decision when the surgery would be performed for symptomatic DLM patients. Retrospective comparative study; level of evidence, 3.

Meniscal rim instability has a high prevalence and a variable location

IntroductionMost classification systems for lateral discoid meniscus do not evaluate instability of the meniscal peripheral rim. Considerable variability in the prevalence of peripheral rim instability has been published, and it appears that instability is underestimated. The purpose of this study was: first, to evaluate the prevalence of peripheral rim instability and its location in the symptomatic lateral discoid meniscus, and second, to investigate if patient age or type of discoid meniscus are possible risk factors for instability.MethodsA cohort of 78 knees that underwent operative treatment due to symptomatic discoid lateral meniscus was analyzed retrospectively for the rate and location of peripheral rim instability.ResultsOut of the 78 knees, 57.7% (45) had a complete and 42.3% (33) had an incomplete lateral meniscus. The prevalence of peripheral rim instability in symptomatic lateral discoid menisci was 51.3%, and with 32.5%, the anterior attachment was most commonly affected, followed by the posterior (30%) and central (10%) attachment. 27.5% of the tested menisci were unstable anteriorly and posteriorly. There was no significant difference in the prevalence of rim instability between the type of discoid menisci (complete vs. incomplete), nor was there a significant correlation for age as a risk factor for instability.ConclusionThe discoid lateral meniscus has a high prevalence and variable location of peripheral rim instability. Meniscal rim stability must be tested and addressed cautiously in all parts and in all types of discoid lateral menisci during operative treatment.

Medial Discoid Meniscus in Children: A Multicenter Case Series of Clinical Features and Operative Results

Background: The discoid medial meniscus is a rare congenital anomaly of the knee. The literature is limited to small case series. Purpose/Hypothesis: Our purpose is to report the clinical manifestations and operative treatments of discoid medial menisci in children from multiple centers in North America. We hypothesized that symptoms and signs, arthroscopic findings, surgical treatments, and outcomes are similar to those for symptomatic discoid lateral menisci. Study Design: Case series; Level of evidence, 4. Methods: A retrospective review identified patients with a diagnosed discoid medial meniscus confirmed at surgery across 8 children’s hospitals between January 2000 and June 2021. The literature on discoid lateral menisci was reviewed and summarized for comparison. Results: A total of 21 patients (9 female, 12 male) with 22 discoid medial menisci were identified. The mean ± SD age at the time of diagnosis was 12.8 ± 3.8 years. The most common symptoms and signs were locking and/or clunking, present in 12 of 22 knees (55%), similar to that reported in patients with discoid lateral menisci. Twelve discoid medial menisci were complete (55%); 8, incomplete (36%); and 2, indeterminate (9%). Tears were present in 13 knees, most commonly horizontal cleavage (54%). Five discoid medial menisci were unstable (23%): 3 for posterior tears and 2 for rim insufficiency. All 22 knees underwent arthroscopic saucerization, and of the 13 torn menisci, 7 (54%) were repaired. The median follow-up was 24 months (range, 2-82 months). Four knees underwent reoperation. All knees that required reoperation had undergone repair for a posteriorly located tear. There was a significant association between operative repair and need for reoperation (P = .0048). High rates of peripheral instability were also noted in case series of patients with discoid lateral menisci. Conclusion: Patient presentations and treatments for those with discoid medial menisci were similar to those reported for patients with discoid lateral menisci. Knees with discoid medial menisci also demonstrated instability attributed to peripheral insufficiency and posterior tears. Tears were present in over half of knees with discoid medial menisci, and reoperation was more common in knees that underwent repair of tears than those without repair.

Arthroscopic surgery for symptomatic discoid lateral meniscus improves meniscal status assessed by magnetic resonance imaging T2 mapping.

Discoid lateral meniscus (DLM) is an anatomic knee variant associated with increased tears and degeneration. This study aimed to quantify meniscal status with magnetic resonance imaging (MRI) T2 mapping before and after arthroscopic reshaping surgery for DLM. We retrospectively reviewed the records of patients undergoing arthroscopic reshaping surgery for symptomatic DLM with ≥ 2-year follow-up. MRI T2 mapping was performed preoperatively and at 12 and 24months postoperatively. T2 relaxation times of the anterior and posterior horns of both menisci and of the adjacent cartilage were assessed. Thirty-six knees from 32 patients were included. The mean age at surgery was 13.7years (range 7-24), and the mean follow-up duration was 31.0months. Saucerization alone was performed on five knees and saucerization with repair on 31 knees. Preoperatively, the T2 relaxation time of the anterior horn of the lateral meniscus was significantly longer than that of the medial meniscus (P < 0.01). T2 relaxation time significantly decreased at 12 and 24months postoperatively (P < 0.01). Assessments of the posterior horn were comparable. The T2 relaxation time was significantly longer in the tear versus non-tear side at each time point (P < 0.01). There were significant correlations between the T2 relaxation time of the meniscus and that of the corresponding area of the lateral femoral condyle cartilage (anterior horn: r = 0.504, P = 0.002; posterior horn: r = 0.365, P = 0.029). The T2 relaxation time of symptomatic DLM was significantly longer than that of the medial meniscus preoperatively, and it decreased 24months after arthroscopic reshaping surgery. The meniscal T2 relaxation time of the tear side was significantly longer than that of the non-tear side. There were significant correlations between the cartilage and meniscal T2 relaxation times at 24months after surgery.

Mid-term effectiveness of arthroscopy and conservative treatment for symptomatic discoid lateral meniscus in middle-aged and elderly patients

To compare the mid-term effectiveness of arthroscopy versus conservative treatment on symptomatic discoid lateral meniscus (SDLM) in middle-aged and elderly patients. The clinical data of 118 middle-aged and elderly patients (154 knees) with SDLM who received arthroscopy or conservative treatment between June 2014 and May 2016 were retrospectively analyzed, including 76 patients (96 knees) in the arthroscopy group (group A) and 42 patients (58 knees) in the conservative treatment group (group B). There was no significant difference in age, gender, and body mass index between the two groups (P>0.05). Compared with group B, the symptoms duration in group A was longer, the incidences of discoid lateral meniscus injury and mechanical symptoms were higher, and the visual analogue scale (VAS) score and Lysholm score before treatment were worse, with significant differences (P<0.05). VAS score and Lysholm score before and after treatment were recorded and compared. The patients in both groups were followed up 60-74 months, with an average of 66.3 months. The follow-up time of group A and group B was (65.9±3.5) months and (67.0±4.0) months respectively, with no significant difference (t=-1.615, P=0.109). At last follow-up, in either group A or group B, the VAS score and Lysholm score significantly improved when compared with those before treatment (P<0.05). The differences of VAS score and Lysholm score in group A before and after treatment were significantly better than those in group B (P<0.05). Arthroscopy and conservative treatment have a satisfactory mid-term effectiveness on SDLM in middle-aged and elderly patients. However, the improvement of symptoms and function of arthroscopy was significantly better than that of conservative treatment. For middle-aged and elderly SDLM patients with invalidated conventional treatment for 6 months, severe clinical symptoms, long duration of symptoms, and combined with mechanical symptoms, arthroscopy should be given priority even if they are complicated with early osteoarthritis.

Arthroscopic Treatment of Symptomatic Discoid Lateral Meniscus and Nondiscoid Meniscus in Adolescent Patients

Background: Discoid lateral meniscus (DLM) is a rare condition. Patient-reported outcomes using validated instruments are underreported in the literature. DLM outcomes have not been directly compared with nondiscoid meniscus (non-DLM) in adolescent patients. Purpose/Hypothesis: This study sought to analyze the difference in patient characteristics, surgical treatment, and patient-reported outcomes for adolescent patients arthroscopically treated for symptomatic DLM and non-DLM pathology. We hypothesized that DLM and non-DLM patient-reported outcomes would be similar. Study Design: Cohort study; Level of evidence, 3. Methods: A retrospective review of patients aged <18 years with symptomatic DLM and non-DLM pathology was completed between 2015 and 2021 at a single academic institution. Chart reviews for patient characteristics and surgical operative indications and technique were completed. Patient-reported outcome scores were prospectively collected preoperatively and at 6 months, 1 year, and 2 years after surgery. Results: Patients in the DLM group (n = 48), when compared with the non-DLM group (n = 45), were younger (12.71 vs 15.78 years, respectively; P < .001) and had lower body mass index (24.53 vs 28.91, respectively; P < .02). Both groups were majority Hispanic and more commonly male (DLM 65% vs non-DLM 60%). All of the DLM patients had surgery on the lateral discoid meniscus (n = 48), whereas the non-DLM group had surgery on the lateral meniscus (n = 37), medial meniscus (n = 7), or both (n = 1). A majority of patients in both groups underwent meniscal repair (DLM 73% and non-DLM 62%), and there was no difference in surgical treatment between groups (P > .05). A statistically significant improvement was seen in International Knee Documentation Committee (IKDC) and Physical Activity Questionnaire (PAQ) scores from the preoperative assessment to 6 months, 1 year, and 2 years after surgery for both DLM and non-DLM groups (P < .05). No difference was found in scores between DLM and non-DLM groups, between sexes, or between age groups (<13 years or ≥13 years) (P > .05). Conclusion: Although patients with DLM were younger and had lower body mass index, the IKDC and PAQ scores were not significantly different between the DLM and non-DLM groups. Both groups showed a significant improvement in scores relative to their preoperative scores. Sex and age did not affect IKDC or PAQ scores.

The discoid lateral meniscus in children: a narrative review of pathology, diagnosis and treatment.

The discoid lateral meniscus (DLM) is a congenital abnormality of the meniscal shape, characterized by a typical central hypertrophy and a diameter larger than a regular meniscus, potentially leading to knee pain and symptoms, especially in children. The present study provides an update and a general review of this uncommon meniscal pathology. The incidence of discoid meniscus is about 0.4-17% for the lateral and 0.1-0.3% for the medial, although, being often asymptomatic, the true prevalence is unknown. We aim to enhance awareness on this subject to medical care provider. A literature search was performed on PubMed, including articles written in English until October 2021. The articles regarding etiology, diagnosis and management of DLM in children or in patients younger than 18 years were reviewed using the narrative approach. Recent literature has shown that DLM is one of the most frequent congenital anomalies of the knee encountered during childhood. While asymptomatic children with incidental finding can be managed nonoperatively, symptomatic painful DLM should be addressed surgically, restoring typical anatomy using saucerization, tear repair, and stable fixation of the meniscus. The risk of osteoarthritis progression seems to be higher in children with operated DLM, imposing prolonged follow-up and cartilage preserving strategies for these patients.

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

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. 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. 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 ± 1.1mm, asymptomatic DLM: 0.1 ± 0.4mm, and normal LM: 0.3 ± 0.6mm, 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. 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. III.

Risk factors for the postoperative effect of symptomatic discoid lateral meniscus after arthroscopy

To explore the influencing factors of the postoperative effect of arthroscopic treatment of symptomatic discoid lateral meniscus (DLM). From September 2008 to September 2015, patients with symptomatic DLM treated by arthroscopic surgery were retrospectively analyzed. The knee function was evaluated by Lysholm scoring system. According to the scoring results, it was divided into excellent (≥90 points), good (80 to 89 points), fair (70 to 79 points) and poor (<70 points). Sixteen research factors were collected, namely gender, operation age, body mass index, work intensity, symptom duration, history of knee injury, involved knee side, DLM classification, DLM injury type, DLM injury site, medial meniscus injury, knee cartilage injury site and degree, Kellgren-Lawrence (K-L) classification, operation method, and latest follow-up time. According to the data type, Kruskall-Wallis rank sum test or χ2 test was used for univariate analysis, and ordinal Logistic regression model was used for multivariate analysis. Univariate analysis showed that the statistically significant factors were included in the multivariate analysis model, and the independent risk factors influencing the curative effect of symptomatic DLM were obtained. According to the inclusion and exclusion criteria, 502 patients were included. Lysholm functional grade at the latest follow-up was higher than that before operation (P<0.001). Univariate analysis showed that there were significant differences in gender, body mass index, work intensity, history of knee injury, age of operation, duration of symptoms, medial meniscus injury, K-L grade, operation method, location and degree of knee cartilage injury among Lysholm functional grades(P<0.05). Ordinal logistic regression analysis showed that female was an independent risk factor for postoperative efficacy (P=0.002, OR=0.370);body mass index (P=0.007, OR=0.894), work intensity(P=0.004, OR=0.525), age of operation(P<0.001, OR=0.953), duration of symptoms(P<0.001, OR=0.989), degree of cartilage damage (P=0.016, OR=0.631) were negatively correlated with Lysholm knee function classification. Arthroscopy is a safe and effective method for the treatment of symptomatic DLM. The gender, body mass index, work intensity, age of operation, duration of symptoms and degree of knee cartilage injury are independent influencing factors for the postoperative efficacy of symptomatic DLM.