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

BACKGROUND: Discoid lateral meniscus (DLM) is the most common congenital abnormality of the meniscus. Tears are common; treatment is frequently not definitive, often requiring reoperation. PURPOSE: 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. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

[Arthroscopic surgery for injuries to the popliteal tendon area of the lateral meniscus].

OBJECTIVE: To investigate the mid-term effect and complications of arthroscopic popliteal tendon suture in the treatment of lateral meniscus injury. METHODS: From January 2016 to December 2020, the data of 57 patients with lateral meniscus popliteal tendon injury treated by arthroscopic popliteal tendon suture fixation were retrospectively analyzed, including 35 males and 22 females, aged from 18 to 47 years old with an average of (32.9±7.9) years old. Knee function was evaluated using the International Knee Documentation Committee (IKDC) and Lysholm scores both before the operation and at the final follow-up. Meniscus healing was evaluated according to the postoperative Barrett standard. Wound healing complications, such as vascular injury, nerve injury, and lower extremity venous thrombosis, were recorded. RESULTS: All 57 patients were followed up for 12 to 58 months with an average of (38.1±14.9) months.The incisions of the patients after the operation were all Grade A healing without infection, popliteal tendon injury, blood vessel injury, nerve injury and lower extremity venous thrombosis.The IKDC score increased from (49.7±3.6) points preoperatively to (88.5±4.4) points in the final follow-up (P<0.05). The Lysholm score increased from (48.8±4.9) points preoperatively to (91.9±3.9) points at the final follow-up (P<0.05). At 3, 6 months and 1 year after operation, according to Barrett's criteria, 54 cases were clinically healed, the healing rate was 94.7% (54/57). CONCLUSION: This study preliminarily confirmed that arthroscopic suture technique can result in clinical stability through suture and fixation of the meniscus in the injured lateral popliteal tendon area. No adverse effects on knee joint function were found in the mid-term follow-up after the operation.

Single-bundle ACL combined with ALL reconstruction yields comparable outcomes in patients with varied anatomical risk factors for ACL graft failure.

BACKGROUND: Anterior cruciate ligament (ACL) graft failure is influenced by factors such as meniscal tears and tibial plateau slope. Combined anterior cruciate ligament (ACL) and anterolateral ligament (ALL) reconstruction has reduced failure rates; however, its efficacy in high-risk patients remains unclear. This study hypothesized that combined ACL and ALL reconstruction would yield similar clinical outcomes in patients with varying risks of ACL failure. PATIENTS AND METHODS: A total of 76 patients who underwent primary single-bundle ACL reconstruction combined with ALL reconstruction between June 2018 and June 2021 were included. The medial tibial slope (MTS), lateral tibial slope (LTS), and anterior tibial translation (ATT) were measured using magnetic resonance imaging and plain radiography of the knee joint. The meniscal lesions were assessed during surgery. Preoperative clinical assessments and final follow-up were conducted using patient-reported outcome measurements (PROMs), including the International Knee Documentation Committee (IKDC) evaluation, Lysholm knee scoring scale, and Tegner Activity scale. PROMs were collected at least two years postoperatively. RESULTS: The average follow-up was 32.5 ± 7.4 months. There were no significant differences in postoperative IKDC score, Lysholm score, or Tegner activity score between patients with or without medial meniscus injury (p = 0.155, 0.914, and 0.042, respectively), with or without lateral meniscus injury (p = 0.737, 0.569, and 0.942, respectively), medial tibial slope > 12° or ≤ 12° (p = 0.290, 0.496, and 0.988, respectively), or lateral tibial slope > 7.4° or ≤ 7.4° (p = 0.213, 0.625, and 0.922, respectively). No significant correlations were found between anterior tibial translation and postoperative IKDC (R = -0.058, p = 0.365), Lysholm (R = -0.017, p = 0.459), or Tegner activity scores (R = -0.147, p = 0.189). CONCLUSION: Our study demonstrates that single-bundle ACL reconstruction combined with ALL reconstruction provides reliable and comparable clinical outcomes in patients with high-risk factors for ACL graft failure, such as increased tibial slope or meniscal injury. Our results suggest that the indications for ALL reconstruction may be expanded to include patients with a high tibial slope or meniscal injury, because these factors have been shown to contribute to increased rotational instability and high rates of ACL graft failure. Future prospective randomized controlled trials with large patient cohorts and long follow-up periods are needed to validate these findings and establish clear guidelines for patient selection and surgical decision-making. LEVEL OF EVIDENCE: Level 3.

Novel Meniscus Transfer Technique: A Case Report.

The meniscus is an essential component of the knee joint, acting as a shock absorber as well as assisting in the transmission of forces. Due to the meniscus importance of the knee, much of the current literature focuses on treatment techniques that can spare and repair the meniscus when it is torn. The unique vasculature of the meniscus often makes repair difficult or, in many cases, impossible. A current focus within orthopedics has been on meniscal allograft transplantation to fill this gap. The lack of a universal surgical technique for graft fixation, along with the current failure rates, demonstrates the need for further improvements. The senior author proposes a novel technique for meniscal allograft transplantation that has shown decreased blood loss and surgical time, while also reducing intra-operative trauma to the knee. This case reports a 16-year-old patient who underwent a right lateral meniscal allograft transplant following a large segmental defect tear of the lateral meniscus. The patient initially underwent arthroscopy and meniscectomy with screw fixation of the lateral femoral condyle lesion. After physical therapy, the patient experienced increased pain and swelling, with magnetic resonance imaging (MRI) demonstrating a meniscal defect unamenable to repair. The patient met indications for meniscal allograft transplantation given the failed meniscectomy, absence of cartilage loss and significant osteoarthritis, and the patient's age of less than 50 years old.

Load Distribution After Serial Resection of the Posterior Horn of the Lateral Meniscus and Subsequent Meniscal Allograft Transplant: A Biomechanical Study.

BACKGROUND: Data are lacking as to when a meniscal allograft transplant (MAT) may be biomechanically superior to a partially resected lateral meniscus. HYPOTHESIS: Lateral MAT using a bone bridge technique would restore load distribution and contact pressures in the tibiofemoral joint to levels superior to those of a partial lateral meniscectomy. STUDY DESIGN: Controlled laboratory study. METHODS: Eleven fresh-frozen human cadaveric knees were evaluated in 5 lateral meniscal testing conditions (native, one-third posterior horn meniscectomy, two-thirds posterior horn meniscectomy, total meniscectomy, MAT) at 3 flexion angles (0°, 30°, and 60°) under a 1600-N axial load. Pressure sensors were used to acquire contact pressure, contact area, and peak contact pressure within the tibiofemoral joint. RESULTS: Limited (one-third and two-thirds) partial lateral posterior horn meniscectomy showed no significant increase in mean and peak contact pressures as well as no significant decrease in contact area compared with the intact state. Total meniscectomy significantly increased mean contact pressure at 0° and 30° (P = .008 and P < .001, respectively), increased peak contact pressure at 30° (P = .04), and decreased mean contact area in all flexion angles compared with the native condition (P < .01). Lateral MAT significantly improved mean contact pressure compared with total meniscectomy at 0° and 30° (P = .002 and P = .003, respectively) and increased contact area at 30° and 60° (P = .003 and P = .009, respectively), although contact area was still significantly smaller (24.1%) after MAT relative to the native meniscus (P = 0.015). However, allograft transplant did not result in better tibiofemoral contact biomechanics compared with limited partial meniscectomy (P > .05). CONCLUSION: The peripheral portion of the lateral meniscus provided the most important contribution to the distribution of contact pressure across the tibiofemoral joint in the cadaveric model. Total meniscectomy significantly increased mean and peak contact pressure in the cadaveric model and decreased contact area. Lateral MAT restored contact biomechanics close to normal but was not superior to the partially meniscectomized status. CLINICAL RELEVANCE: Surgeons should attempt to preserve a peripheral rim of the posterior lateral meniscus. Meniscal allograft transplant appears to improve but not normalize mean contact pressure and contact area relative to total lateral meniscectomy.

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

PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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 OF EVIDENCE: Level III.

Congenital absence of the lateral meniscus: A case report.

BACKGROUND: Congenital absence of the menisci is a rare anatomical variation characterized by the absence or underdevelopment of one or both menisci in the knee joint. The menisci are crucial in load distribution, joint stability, and shock absorption. Understanding the clinical presentation, diagnosis, and management of this condition is important for optimal patient care. CASE SUMMARY: A 27-year-old male with a long-standing history of knee pain underwent diagnostic arthroscopy, revealing a congenital absence of the meniscus. The patient's clinical findings, imaging results, surgical procedures, and pertinent images are detailed. This case presents a unique aspect with the congenital absence of the meniscus, contributing valuable insights to the literature on rare anatomical anomalies. CONCLUSION: This case of congenital absence of the menisci highlights the diagnostic challenges posed by rare anomalies. The diagnostic arthroscopy played a crucial role in identifying the absence of the meniscus and providing an explanation for the patient's persistent knee pain. The case underscores the importance of individualized treatment approaches, including physical therapy, for optimal management of rare meniscal anomalies. Further research is warranted to explore effective management strategies for the aforementioned cases and to expand our knowledge of these rare conditions.

Long Term Surgical and Radiological Outcome of Discoid Lateral Meniscus: An Updated Systematic Review.

Purpose of the study: This study aimed to reach a consensus for ideal surgical treatment of discoid lateral meniscus (DLM) and to evaluate its long term surgical and radiological outcome. Methods: All authors independently searched for peer reviewed publications with keywords like discoid lateral meniscus, tibial menisci abnormalities, tibial menisci surgery and clinical outcome and their representative Medical Subjects Headings (MeSH) in databases of PubMed, EBSCO, Cochrane Central Register of Controlled Trials, from inception to December 2022. Original articles in English language on discoid lateral meniscus reporting clinical, surgical, or radiological outcomes with five or more years of follow-up were included in this systematic review. Study details and outcome data were analysed according to the age, follow-up period, kind of surgery, DLM type, and alignment. Results: Our search strategy yielded 654 articles in PubMed, 222 articles in EBSCO and 5 articles in CENTRAL i.e. a total of 881 articles. After detailed assessment and screening, 12 articles were included in the final analysis, which included 444 DLM cases. The mean patient age at surgery ranged from 9.9 to 35.9 years, and the mean follow-up period ranged from 5.2 to 16 years. Partial meniscectomy and meniscoplasty are the recommended treatment because of the concerns of degenerative arthritis development after the total and subtotal meniscectomies. Two studies have documented better results with meniscal allograft transplantation. Conclusion: Satisfactory clinico-radiological outcome can be obtained after surgical treatment of discoid lateral meniscus with meniscus reshaping and repair of peripheral unstable part. Meniscal allograft transplantation (MAT) is gaining popularity in patients with total meniscectomy with satisfactory long term functional outcome.

Decay-Accelerating Factor Differentially Associates With Complement-Mediated Damage in Synovium After Meniscus Tear as Compared to Anterior Cruciate Ligament Injury.

We have reported that anterior cruciate ligament (ACL) injury leads to the differential dysregulation of the complement system in the synovium as compared to meniscus tear (MT) and proposed this as a mechanism for a greater post-injury prevalence of post traumatic osteoarthritis (PTOA). To explore additional roles of complement proteins and regulators, we determined the presence of decay-accelerating factor (DAF), C5b, and membrane attack complexes (MACs, C5b-9) in discarded surgical synovial tissue (DSST) collected during arthroscopic ACL reconstructive surgery, MT-related meniscectomy, osteoarthritis (OA)-related knee replacement surgery and normal controls. Multiplexed immunohistochemistry was used to detect and quantify complement proteins. To explore the involvement of body mass index (BMI), after these 2 injuries, we examined correlations among DAF, C5b, MAC and BMI. Using these approaches, we found that synovial cells after ACL injury expressed a significantly lower level of DAF as compared to MT (p<0.049). In contrast, C5b staining synovial cells were significantly higher after ACL injury (p<0.0009) and in OA DSST (p<0.039) compared to MT. Interestingly, there were significantly positive correlations between DAF & C5b (r=0.75, p<0.018) and DAF & C5b (r=0.64 p<0.022) after ACL injury and MT, respectively. The data support that DAF, which should normally dampen C5b deposition due to its regulatory activities on C3/C5 convertases, does not appear to exhibit that function in inflamed synovia following either ACL injury or MT. Ineffective DAF regulation may be an additional mechanism by which relatively uncontrolled complement activation damages tissue in these injury states.

Arthroscopic inferior leaf meniscectomy of the involved anterior horn in the lateral meniscus horizontal tear via an accessary extreme far anteromedial portal.

BACKGROUND: An accessory extreme far anteromedial portal can improve visualisation and ease inferior leaf meniscectomy in patients with lateral meniscal anterior horn horizontal tears. However, the therapeutic outcomes of adding an accessory extreme far anteromedial portal remain unclear. This study aimed to evaluate the clinical efficacy of adding an accessory extreme far anteromedial portal for treating lateral meniscal horizontal tears involving the anterior horns. METHODS: This retrospective study included 101 patients with anterior horn involvement in lateral meniscal horizontal tears who underwent arthroscopic unstable inferior leaf meniscectomy between January 2016 and December 2020. The pathologies were diagnosed using physical examinations and magnetic resonance imaging. The anterior horn involved in the lateral meniscal horizontal tears was treated using inferior leaf meniscectomy. The primary endpoints were changes in the visual analogue scale, Lysholm, International Knee Documentation Committee, and Tegner scores at the final follow-up. The secondary endpoint was meniscal cure rate at 3 months postoperatively. The preoperative and postoperative functional scores were compared. The occurrence of complications was recorded. RESULTS: All patients were followed up for an average of 4.9 ± 1.2 years (range 2.3-7.5 years). After 4 months, none of the patients experienced pain, weakness, instability, or tenderness in the lateral joint line, achieving an imaging cure rate of 98%. At the final follow-up, significant postoperative improvements were observed in the average values of the visual analogue scale score (3.5 ± 0.7 vs. 0.7 ± 0.6), Lysholm score (62.7 ± 4.4 vs. 91.8 ± 3.1), International Knee Documentation Committee score (61.9 ± 3.7 vs. 91.7 ± 9.5), and Tegner score (2.0 ± 0.7 vs. 6.1 ± 0.7). Excellent Lysholm scores were obtained in 81 patients, and good outcomes were obtained in 18 patients, with an excellent-to-good rate of 98.0%. CONCLUSIONS: Inferior leaf resection via the accessory far anteromedial portal is a safe treatment option for the involved anterior horn in lateral meniscal horizontal tears. This approach enhances visibility and facilitates surgical procedures, with minimal complications.

Utility of Adult-Based Discoid Lateral Meniscus Diagnostic Criteria in a Pediatric Population.

Background: Commonly cited discoid lateral meniscus (DLM) imaging definitions are based on adult magnetic resonance imaging (MRI) measurements. This pathology commonly presents in pediatric populations; however, whether accepted adult measurements reliably apply to children and adolescents is unknown. Purpose/Hypothesis: This purposes of the study were to determine (1) the utility of applying adult-accepted MRI definitions of DLM to pediatric patients, (2) whether sex differences affect the applicability of the criteria, and (3) whether MRI magnet strength and/or tear presence affect MRI measurements for diagnosing DLM in pediatric patients. It was hypothesized that MRI criteria for DLM would be similar in adults and pediatric patients. Study Design: Case series; Level of evidence, 4. Methods: A total of 100 consecutive MRIs from pediatric patients with DLM were evaluated, with 91 scans included. Two study authors independently reviewed the MRIs, evaluating meniscal height and width on sagittal and coronal images, "bow tie signs" on sagittal images, tibial sagittal and coronal width, and tear presence. For analysis, MRI magnet strength was dichotomized into high (>1.5 T) and low (<1.5 T) groups. Results: The mean age of the patients at MRI evaluation was 12.3 ± 3.4 years; 51% of the patients were male, and 56% of the scans were of left knees. Included patients with DLM showed a mean of 3.68 bow tie signs, a sagittal total anterior to posterior meniscal width/tibial width ratio of 73%, a coronal meniscal width/tibial width ratio of 30%, and a coronal, transverse width of the lateral meniscus at the midportion of the meniscal body of 20.6 ± 7.7 mm. The MRI tesla strength of the images included in this study ranged from 0.3 to 3. It was determined that high- versus low-resolution MRI scans did not affect the inter- or intraobserver reliability of the MRI measurments (P > .05). However, several measurements showed improved intraclass correlation coefficients with increased tesla strength. Conclusion: This study confirms that pediatric patients with DLM, diagnosed by board-certified pediatric sports medicine orthopaedic surgeons, have measurements on MRI consistent with adult DLM diagnostic criteria. This finding held true regardless of sex or MRI tesla strength. Pediatric patients with DLM had >3 bow tie signs, >70% sagittal tibial plateau coverage, >14 mm coronal width, and >20% coronal tibial plateau coverage on MRI.

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

PURPOSE: 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. METHODS: Data were collected from 611 patients with symptomatic DLM diagnosed using magnetic resonance imaging between April 2003 and May 2022. Twenty features, including demographic, clinical and radiological data and 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. RESULTS: Extreme gradient boosting classifier was 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. CONCLUSION: 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 OF EVIDENCE: Level III.

Discoid Double-layered Lateral Meniscus: A Case Report.

Introduction: Abnormalities of the double-layered meniscus are rare and can be difficult to diagnose. The main pathology in this abnormality, which is predominantly seen in the lateral compartment, is an accessory meniscus lying over the normal meniscus. Anatomically, this structure can appear in different forms. Although other meniscal abnormalities associated with a double-layered meniscus have been reported, this case presents a previously undescribed type in the literature. Case Report: A 12-year-old girl presented to our clinic with complaints of knee locking and pain. When the patient underwent arthroscopy, an accessory incomplete discoid meniscus was found overlying the normal lateral meniscus. We performed an excision of the upper accessory meniscus and the patient had no problems during 3 years of follow-up after surgery. Conclusion: Abnormalities of the lateral meniscus are rare and can be difficult to diagnose. In cases where we suspect a meniscal abnormality, a proper arthroscopic examination should be performed and if a discoid meniscus is seen, it should be considered that this may be a double-layered meniscus.

Posterior cruciate ligament tibial attachment sacrifice percentage is higher in cruciate-retaining total knee arthroplasty in patients with discoid lateral meniscus.

BACKGROUND: The posterior cruciate ligament (PCL) attachment may be damaged in cruciate-retaining total knee arthroplasty (CR-TKA) using the complete resection for tibial preparation, and resection amount varies greatly among individuals. Discoid lateral meniscus (DLM) is one of the most common anatomic knee variants. This study aimed to evaluate the difference in PCL attachment sacrifice in CR-TKA between patients with and without DLM. METHODS: Fifty-one knees in the study group (DLM group) were matched 1:1 to 51 control knees (non-DLM group) by age, sex, and maximum width of the tibial plateau. The percentage of the sacrificed PCL attachment and the morphological parameters of the tibial plateau were evaluated using magnetic resonance imaging (MRI) in a blind manner. RESULTS: With a tibial cut simulated at a 0°, 3°, and 7° osteotomy slope, the mean PCL attachment resection percentages in the non-DLM group were 40.5%, 53.6%, and 72.6%, respectively. The corresponding resection percentages in the DLM group were 61.0% (P < 0.001), 73.3% (P < 0.001), and 85.7% (P < 0.001), respectively. The percentage of the minimum meniscus width to the maximum tibia width showed a weak positive correlation with the percentage of PCL attachment sacrifice. CONCLUSIONS: A significantly greater portion of PCL attachment was sacrificed in DLM patients undergoing CR-TKA using the complete proximal tibia resection. Attention should be paid to PCL attachment resection during CR-TKA in patients with DLM, and alternative techniques or prosthesis types should be considered.

Ramp-like lateral meniscus tear. Description of an infrequent lesion.

Numerous studies on meniscal tears have been published, a pathology that continues to evolve in terms of treatment and patient outcomes. As our understanding of anatomy and biomechanics improves, new entities have emerged. The lateral meniscus, especially its posterior attachment, tends to be overlooked due to its greater mobility compared to the medial meniscus. Evaluating the instability of the posterior horn poses a challenge, even during arthroscopy, therefore, it is crucial to understand the posterior menisco-synovial detachment lesions, which are indeed real and, to date, haven't received enough attention in the existing literature. The aim is to describe a new entity affecting the posterior synovial attachment of the lateral meniscus, without injury to the posterior horn of the lateral meniscus (PHLM). We also aim to present a case report detailing the intraoperative diagnosis and management of a 20-year-old patient with a sports trauma that led to a combined anterior cruciate ligament (ACL) and lateral meniscus tear managed with arthroscopic ACL reconstruction and all-inside meniscal suture. Through conventional arthroscopic evaluation of the posterior capsule anatomy and dissections, we have identified a distinct lesion of the PHLM at the menisco-synovial junction. Further research is necessary in this field to understand the biomechanical repercussions and determine the ideal surgical management.

Repair of radial tears of the lateral meniscus on a stable knee: Results at a minimum follow-up of 2 years.

INTRODUCTION: In younger patients, meniscal repair is recommended for isolated lateral meniscus tears that are most often due to acute trauma. But there is little published data on the outcomes of repairing this specific type of lesion. The goal of this study was to evaluate the clinical outcomes, report the failure rate of repairing radial tears of the lateral meniscus in stable knees and determine the risk factors for failure. MATERIALS AND METHODS: All patients who had a stable knee and underwent arthroscopic repair of a radial lateral meniscus tear between April 2013 and December 2019 were reviewed retrospectively. Failure was defined as revision surgery for recurrence of symptoms (pain, locking) with intraoperative confirmation that the meniscus did not heal. The following data were collected: demographics (age, sex, BMI), time to surgery, clinical outcome scores (Tegner, Lysholm, IKDC), surgical details (repair technique, lesion zone, number of sutures). RESULTS: Thirty patients were included having a mean age of 20.1years (14-31). The follow-up ranged from 24 to 110months (mean 66.8±25.2). An all-inside repair was done in 6 patients (20%); an outside-in technique was done in 17 patients (57%) and a combination of all-inside and outside-in was done in 7 patients (23%). Four patients (13%) had a recurrence of their symptoms later on, while participating in sports. All the recurrences were at the initial tear site. The time to revision surgery was 16, 19, 24 and 37months in these four patients (mean 24±9). All the other patients were able to resume sports at their pre-injury level. Significant improvement in the IKDC, Lysholm and Tegner functional scores were found between the preoperative and postoperative assessments. No statistically significant risk factors for failure were identified. DISCUSSION: The functional healing rate after repair of a radial lateral meniscus tear in a stable knee was 86% at a mean follow-up of 5years, with the surgical technique having no impact on the long-term result. Most of the failures occurred within 2years of the repair procedure. We recommend repairing these tears as they have considerable healing potential. LEVEL OF EVIDENCE: IV; retrospective observational cohort study.

Association Between MRI Signal Intensity of the Repaired Lateral Meniscus and Residual Anterolateral Knee Laxity After ACL Reconstruction.

Background: Anterolateral knee laxity (ALLx) has been linked to tears of the lateral meniscus (LM) and anterior cruciate ligament (ACL) injury. Purpose: To investigate the longitudinal relationship between the signal intensity (SI) of the repaired LM on magnetic resonance imaging (MRI) and residual ALLx after ACL reconstruction (ACLR). Study Design: Cohort study; Level of evidence, 3. Methods: Included were 87 patients who underwent double-bundle ACLR and lateral meniscal repair (mean age, 23.5 years; body mass index, 23.7 kg/m2; 56 women) at a single institution between 2010 and 2019. Proton density-weighted (PDW) and T2-weighted (T2W) MRI was performed at 3, 6, and 12 months postoperatively, and the SI ratio (SIR) was calculated as (SI of the repaired LM)/(SI of the posterior cruciate ligament). At the 12-month follow-up, ALLx was evaluated using the pivot-shift test; an International Knee Documentation Committee grade ≥1 indicated residual ALLx. Results: Overall, 12 patients (13.8%) exhibited ALLx at 12 months postoperatively. At 3 months postoperatively, the SIR on PDW images (SIR-PDW) was significantly higher in patients with ALLx versus those without ALLx (1.98 ± 0.77 vs 1.49 ± 0.52, respectively; P = .007); there was no difference in the SIR on T2W images between the groups. SIR-PDW at 3 months postoperatively was correlated negatively with patient age (r = -0.308, P = .004). When patients were stratified into a younger (≤22 years; n = 53; ALLx = 7 [13.2%]) and an older (>22 years; n = 34; ALLx = 5 [14.7%]) group, the area under the receiver operating characteristic curves (AUCs) for SIR-PDW in the younger group were statistically significant for predicting the prevalence of ALLx at all follow-up times (AUCs, 0.733-0.788) with optimal cutoff values of 2.00 at 3 months, 1.50 at 6 months, and 1.50 at 12 months. Logistic regression analysis revealed that if younger patients consistently had higher SIR-PDW values than the cutoff values, they were more likely to have residual ALLx (odds ratios, 10.24-23.57). Conclusion: For younger patients who underwent both ACLR and lateral meniscal repair, higher MRI SI of the repaired LM was associated with a higher prevalence of residual ALLx.

Incidence and Characteristics of Knee Ligament and Meniscal Injuries in Patients With Posterolateral Tibial Plateau Fractures.

Background: Anterior cruciate ligament (ACL) tears are commonly seen with concomitant injuries to the posterolateral tibial plateau, while the occurrence of ACL injuries in posterolateral tibial plateau fractures (PTPFs) remains unclear. Purpose: To (1) explore the incidence of knee ligament (anterior or posterior cruciate ligament, medial or lateral collateral ligament) and medial or lateral meniscus injuries in patients with PTPF and (2) find reliable PTPF-related parameters to predict the risk of knee ligament and meniscal injuries. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Patients diagnosed with PTPF who had computed tomography and magnetic resonance imaging (MRI) data were identified. Morphological parameters of the PTPF were measured on sagittal computed tomography images. Knee ligament and meniscal injuries were assessed using MRI. The association of ACL injuries with meniscal injuries was analyzed. Receiver operating characteristic (ROC) analysis was used to determine the value and cutoff point of the PTPF morphological parameters for diagnosing complete in-substance ACL tears. Results: Overall, 113 patients with PTPF were included. ACL injuries were present in 94 (83.2%) patients, including 43 (38.1%) avulsion fractures and 28 (24.8%) complete in-substance tears. Patients with in-substance ACL tears had a higher incidence of lateral meniscus posterior horn tears compared with the other patients (PBonferroni < .001). ROC analysis revealed that both the fracture depression angle (cutoff point, 25.5°) and the posterior articular surface loss percentage (cutoff point, 37.5%) had a sensitivity >90% and a specificity >80% for the diagnosis of complete in-substance ACL tears. Conclusion: ACL injuries were seen in 83.2% of the study patients. Complete in-substance ACL tears were associated with an increased incidence of lateral meniscus posterior horn tears. Among PTPF parameters, fracture depression angle and posterior articular surface loss percentage showed a high predictive value for the presence of complete in-substance ACL tears, thereby reducing delays in diagnosis and treatment.

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.