Inhibition of Phlpp1 preserves the mechanical integrity of articular cartilage in a murine model of post-traumatic osteoarthritis.

OBJECTIVE: Phlpp1 inhibition is a potential therapeutic strategy for cartilage regeneration and prevention of post-traumatic osteoarthritis (PTOA). To understand how Phlpp1 loss affects cartilage structure, cartilage elastic modulus was measured with atomic force microscopy (AFM) in male and female mice after injury. METHODS: Osteoarthritis was induced in male and female Wildtype (WT) and Phlpp1-/- mice by destabilization of the medial meniscus (DMM). At various timepoints post-injury, activity was measured, and knee joints examined with AFM and histology. In another cohort of WT mice, the PHLPP inhibitor NSC117079 was intra-articularly injected 4 weeks after injury. RESULTS: Male WT mice showed decreased activity and histological signs of cartilage damage at 12 but not 6-weeks post-DMM. Female mice showed a less severe response to DMM by comparison, with no histological changes seen at any time point. In both sexes the elastic modulus of medial condylar cartilage was decreased in WT mice but not Phlpp1-/- mice after DMM as measured by AFM. By 6-weeks, cartilage modulus had decreased from 2 MPa to 1 MPa in WT mice. Phlpp1-/- mice showed no change in modulus at 6-weeks and only a 25% decrease at 12-weeks. The PHLPP inhibitor NSC117079 protected cartilage structure and prevented signs of OA 6-weeks post-injury. CONCLUSIONS: AFM is a sensitive method for detecting early changes in articular cartilage post-injury. Phlpp1 suppression, either through genetic deletion or pharmacological inhibition, protects cartilage degradation in a model of PTOA, validating Phlpp1 as a therapeutic target for PTOA.

Clinical outcome of iterative meniscal suture after ACL reconstruction at a minimum of 2 years' follow-up.

INTRODUCTION: Failure rates in meniscal suture associated to ACL reconstruction range from 10 to 26.9%, often leading to meniscectomy. In young patients, the wish to conserve the meniscus may lead to iterative suture, if the lesion allows. There are no data available for clinical results of repeat meniscal suture at the same site as the primary lesion in a stabilized knee. The immediate socioeconomic cost, compared to meniscectomy, needs to be taken into account, and benefit needs to be demonstrated. The main aim of the present study was to assess the rate of secondary meniscectomy after iterative meniscal suture in stabilized knees. The study hypothesis was that failure rates are higher in iterative isolated meniscal suture after ligament reconstruction than in primary repair. MATERIAL AND METHODS: This single-center retrospective study analyzed patients receiving iterative meniscal suture on stable knee, between 2009 and 2019, with a minimum 26 months' follow-up. Twenty-three patients were analyzed: 15 male, 8 female; mean age at iterative suture, 28.1±7.9 years (range, 14-49 years); mean BMI, 24.2±2.9kg/m2 (range, 19-31). Mean time to recurrence was 38.9±25.1 months (range, 6-93 months). Initial ACL graft used the patellar ligament in 69.6% of cases (n=16) and the hamstrings in 30.4% (n=7). Mean differential laximetry before iterative suture was 1.7±0.3mm (range, 1.2-2.3mm). Iterative suture was in the medial meniscus in 69.6% of cases (16/23) and in the lateral meniscus in 30.4% (7/23). Risk factors for failure, defined by requirement for meniscectomy, were assessed. Functional results were assessed on Knee injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee (IKDC) score and Tegner score. RESULTS: The failure rate was 48% (11/23), incorporating all lesions together. Bucket-handle tear was most frequently associated with failure (91%; p<0.01). There was significant improvement after iterative suture in subjective IKDC score (51.6±15.2 vs. 81.3±15.6; p<0.001) and KOOS scores: symptoms and stiffness, 66.6±13.7 vs. 91.1±7.53 (p<0.001); pain, 79.2±12.7 vs. 93.4±7.4 (p<0.01); function, 91.3±11.2 vs. 97.9±4.44 (p<0.001); quality of life, 38.1±23.2 vs. 62.3±30.1 (p<0.001). CONCLUSION: The failure rate for iterative meniscal suture on stabilized knee was 48%. Bucket-handle tear was a major risk factor for failure (91%). Despite these high failure rates, functional results systematically improved. LEVEL OF EVIDENCE: IV.

Diagnostic Accuracy of MRI in Knee Meniscus Tear and ACL Injury.

Objective: Knee injuries are very common and may lead to other secondary injuries if effective treatment is lacking. In addition to standardized physical examination, magnetic resonance imaging (MRI) is sometimes considered an aid in the diagnosis of knee trauma. In order to have a more accurate diagnosis of knee injuries, we compared MRI with arthroscopic findings in this study to evaluate the diagnostic accuracy of MRI for meniscal tears and anterior cruciate ligament injuries of the knee. Methods: One hundred and ten patients with suspected meniscal tears and anterior cruciate ligament injuries of the knee who were admitted to our hospital from June 2020 to June 2022 were selected as study subjects, and the clinical data of the patients were retrospectively analyzed. All patients underwent MRI for preoperative diagnosis, and the sensitivity, specificity, MRI findings, and confirmation of diagnosis were compared and analyzed, and the accuracy of MRI in diagnosing meniscal tears and ACL injuries of the knee was analyzed. Results: The mean ACL angle was (98.0 ± 5.4) in the MRI group and (118.0 ± 6.8) in the arthroscopic group, the difference between the two groups was statistically significant P < .05. The mean L/H value of the ACL was (2.12 ± 0.38) in the MRI group and (1.81 ± 0.19) in the arthroscopic group, which was statistically different between the two groups (P < .05). Among the patients, 68 meniscal injuries were found in the MRI examination, including 45 cases of knee meniscal tears and 23 cases of anterior cruciate ligament injuries. The sensitivity, specificity, positive and negative predictive values, agreement rate, kappa value, and Youden index of MRI in diagnosing meniscal tears and ACL injuries were all high. Conclusions: In terms of sensitivity and accuracy, MRI is an excellent imaging technique for the diagnosis of meniscal tears and anterior cruciate ligament injuries of the knee.

A Systematic Review of Adverse Events and Complications After Isolated Posterior Medial Meniscus Root Repairs.

BACKGROUND: Medial meniscus posterior root (MMPR) tears are recognized as a substantial cause of disability and morbidity. However, meniscus root repair, regardless of technique, is not without potential complications. PURPOSE: To evaluate the reported incidence of complications and adverse events after isolated MMPR repair. STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: A systematic review was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using Embase, PubMed, and Scopus databases with the following search terms combined with Boolean operators: "meniscus,""root," and "repair." Inclusion criteria consisted of level 1 to 4 human clinical studies in English or English-language translation reporting complications and adverse events after isolated posterior medial meniscus root repairs. The overall incidence of specific complications was estimated from the pooled sample of the included studies. RESULTS: Eleven studies with a total pooled sample of 442 patients were identified. The mean patient age was 58.1 years, while the mean final follow-up time was 37.2 months (range, 12-84.8 months). The overall incidence of complications was 9.7% (n = 43/442), with the most commonly reported complication being progressive degenerative changes within the knee (10.4%; n = 25/240; n = 5 studies). A total of 1.25% (n = 3/240) of patients who experienced degenerative changes required conversion to total knee arthroplasty. Repair failures were reported in 3.1% (n = 10/327; n = 8 studies) of patients. CONCLUSION: Repairing MMPR tears is critical in preventing accelerated progression of knee osteoarthritis in patients without significant knee osteoarthritis preoperatively. While this repair is still recommended and necessary in appropriate patients, this review found that the incidence of complications after isolated posterior medial meniscus root repair was 9.7%, primarily involving the presence of progressive degeneration, while repair failure was reported in 3% of patients.

Posterolateral tibial plateau bone bruises in anterior cruciate ligament (ACL) injuries and its association with lateral meniscal injuries.

INTRODUCTION: This study examined the prevalence of posterolateral tibial bone bruising in isolated anterior cruciate ligament (ACL) injuries, prevalence of meniscal injuries in ACL injuries, as well as the association between posterolateral tibial bone bruising and lateral meniscal tears among those with ACL injury undergoing Primary ACL Reconstruction. MATERIALS AND METHODS: Retrospective data on 130 patients who underwent primary ACL reconstructions was analysed. Their preoperative magnetic resonance images (MRI) were reviewed for the presence of posterolateral tibial bone bruise. The presence of meniscal injuries was recorded based on the arthroscopic findings from the operative records. RESULTS: 95 patients were recruited into the study. The prevalence of posterolateral bone bruise in this study was 41%. There was a statistically significant difference when comparing the prevalence of bone bruising to the time of injury to MRI (p<0.001). The prevalence of an injury to at least one meniscus at the time of ACLR surgery was 83.2%. The prevalence of lateral meniscus injuries in patients with bone bruise was found to be 53.9%. The crude odds ratio of a patient having a lateral meniscal tear in the presence of bone bruising was 1.56 (0.68, 3.54). This figure was even higher when it was adjusted for time to MRI and was 2.06 (0.77, 5.46). CONCLUSION: Prevalence of posterolateral tibial bone bruising in our study was 41%, and the prevalence of meniscal injury to either meniscus at the point of surgery was 83.2%, out of which the lateral meniscus tears were identified during ACLR surgery in 47.3% of the patients. We found there was no association between posterolateral tibial bone bruising to sex, age and mode of injury, but was sensitive to the interval between time of injury and MRI. The overall prevalence of lateral meniscal tears was higher in patients with posterolateral bone bruising but was not statistically significant with a P value of 0.31; however, the Crude odd ratio was 1.56 (0.68, 3.54) and was higher when adjusted to time of injury to MRI 2.06 (0.77, 5.46). We suggest for MRI to be done as soon as possible after injury in regard to bone bruising identification. We should be vigilant to look for lateral meniscal tears and anticipate for its repair in ACL injuries, especially so when we identify posterolateral tibial bruising on the preoperative MRI.

Combined Medial And Lateral Bucket Handle Meniscus Tears With Associated Complete Anterior Cruciate Ligament Tear: A Case Report.

The majority of meniscal tears in bucket handles are associated with anterior cruciate ligament (ACL) impairment. Its a rare condition which is rarely encountered when the meniscus has a bucket handle on both sides of the compartment. Here we present the case of a 28-year- old male cricket player with a total ACL rupture, a double Posterior Cruciate ligament (PCL) sign on MRI (Magnetic Resonance Imaging), an uncommon occurrence of a complex bucket handle rupture of the medial meniscus with a double PCL sign. It was a complete ACL tear and displaced bucket handle medial meniscus that was also visible on the magnetic resonance imaging. In this report, double PCL sign was shown on MRI and that was confirmed during the arthroscopic procedure.

Evaluation and Treatment of Knee Pain: A Review.

Importance: Approximately 5% of all primary care visits in adults are related to knee pain. Osteoarthritis (OA), patellofemoral pain, and meniscal tears are among the most common causes of knee pain. Observations: Knee OA, affecting an estimated 654 million people worldwide, is the most likely diagnosis of knee pain in patients aged 45 years or older who present with activity-related knee joint pain with no or less than 30 minutes of morning stiffness (95% sensitivity; 69% specificity). Patellofemoral pain typically affects people younger than 40 years who are physically active and has a lifetime prevalence of approximately 25%. The presence of anterior knee pain during a squat is approximately 91% sensitive and 50% specific for patellofemoral pain. Meniscal tears affect an estimated 12% of the adult population and can occur following acute trauma (eg, twisting injury) in people younger than 40 years. Alternatively, a meniscal tear may be a degenerative condition present in patients with knee OA who are aged 40 years or older. The McMurray test, consisting of concurrent knee rotation (internal or external to test lateral or medial meniscus, respectively) and extension (61% sensitivity; 84% specificity), and joint line tenderness (83% sensitivity; 83% specificity) assist diagnosis of meniscal tears. Radiographic imaging of all patients with possible knee OA is not recommended. First-line management of OA comprises exercise therapy, weight loss (if overweight), education, and self-management programs to empower patients to better manage their condition. Surgical referral for knee joint replacement can be considered for patients with end-stage OA (ie, no or minimal joint space with inability to cope with pain) after using all appropriate conservative options. For patellofemoral pain, hip and knee strengthening exercises in combination with foot orthoses or patellar taping are recommended, with no indication for surgery. Conservative management (exercise therapy for 4-6 weeks) is also appropriate for most meniscal tears. For severe traumatic (eg, bucket-handle) tears, consisting of displaced meniscal tissue, surgery is likely required. For degenerative meniscal tears, exercise therapy is first-line treatment; surgery is not indicated even in the presence of mechanical symptoms (eg, locking, catching). Conclusions and Relevance: Knee OA, patellofemoral pain, and meniscal tears are common causes of knee pain, can be diagnosed clinically, and can be associated with significant disability. First-line treatment for each condition consists of conservative management, with a focus on exercise, education, and self-management.

Medial meniscal repair in stable knees: Survival rate and risk factors for failure at a minimum of 5 years.

INTRODUCTION: The menisci play a major role in the protection of the knee against osteoarthritis. A medial meniscus (MM) tear occurring in a stable knee is more at risk of repair failure than a suture concomitant with reconstruction of the anterior cruciate ligament. HYPOTHESIS: The survival of MM sutures in stable knees depends on the type of lesion. MATERIALS AND METHODS: This retrospective study was carried out as part of the 2022 Francophone Arthroscopy Society's symposium, across 10 centers (Bordeaux-Mérignac, Caen, Lille, Lille Louvière, Lyon, Marseille, Toulouse, Saint-Étienne, Strasbourg and Versailles) including medial meniscus sutures in stable knees performed before the end of 2017 (minimum 5 years of follow-up) with a collection of demographic, imaging, suture and postoperative protocol data, and a functional evaluation using the Knee injury and Osteoarthritis Outcome score (KOOS). The aim of this study was to analyze the medial meniscus sutures in stable knees and to evaluate their survival and their risk factors for failure according to the type of lesion; failure being defined by the use of a meniscectomy. RESULTS: Three-hundred and sixty-seven MM sutures, including 122 bucket-handle tears, were included. The KOOS score was improved by the meniscal suture by an average of 22.2 points for each sub-score (p<0.05), with an improvement, which was more marked for the bucket-handle tears. The failure rate, defined by revision surgery by meniscectomy, was 33% on average (42% for bucket-handles tears, 26% for others). The probability of survival was reduced for bucket-handle tears (62% at 5 years versus 77% for the other types). For all lesions, the main risk factor identified for failure was immediate weight-bearing [OR=3.6 (1.62; 7.98), p=0.0016]. Smoking was a failure risk factor for bucket-handle tears [OR=5.76 (1.81; 18.35), p=0.003]. CONCLUSION: MM sutures in stable knees improve knee function but present a different risk of failure depending on the type of lesion treated with a higher risk of failure for bucket-handle tears with the need for caution to be applied with regards to weight-bearing and smoking. LEVEL OF EVIDENCE: IV; retrospective series.

Delaying ACL reconstruction is associated with increased rates of medial meniscal tear.

PURPOSE: The aim of this study was to evaluate the relationship between the time from injury to ACL reconstruction (ACLR) and the rate as well as repairability of meniscal tears. Secondary aims were to evaluate the relationship between meniscal injury and Tegner Activity Scale, age, BMI, and gender. METHODS: Between 2012 and 2022, 1,840 consecutive ACLRs were performed. A total of 1,317 ACLRs were included with a mean patient age of 31.2 years ± 10.5 [16-60]. Meniscal tear was assessed during arthroscopy using the ISAKOS classification. Time from injury to ACLR, Tegner Activity Scale, age, BMI and gender were analysed in uni- and then in multivariate analyses. Patients were divided into four groups according to the time from injury to surgery: < 3 months (427; 32%), 3-6 months (388; 29%), 6-12 months (248; 19%) and > 12 months (254; 19%). RESULTS: Delaying ACLR > 12 months significantly increased the rate of medial meniscal (MM) injury (OR 1.14; p < 0.001). No correlation was found between a 3- or 6-month time from injury to surgery and MM tear. Performing ACLR > 3, 6, or 12 months after injury did not significantly increase the rate of lateral meniscal (LM) injury. Increasing Tegner activity scale was significantly associated with a lower rate of MM injury (OR 0.90; p = 0.020). An age > 30 years (OR 1.07; p = 0.025) and male gender (OR 1.13; p < 0.0001) was also associated with an increased rate of MM injury. Age > 30 years decreased the rate of MM repair (OR 0.85; p < 0.001). Male gender increased the rate of LM tear (OR 1.10; p = 0.001). CONCLUSION: Performing ACLR more than 12 months after injury was associated with increased rates of MM injury but not with lower rates of repairable lesions. An increased pre-injury Tegner activity score was associated with a decreased rate of MM tear. Age > 30 years was associated with an increased rate of MM tear with concomitant ACL injury and a decreased rate of repairability of MM tear. ACLR should be performed within 12 months from injury to prevent from the risk of MM injury. LEVEL OF EVIDENCE: Level III.

Factors Associated With Meniscal and Articular Cartilage Injury in the PLUTO Cohort.

BACKGROUND: Anterior cruciate ligament (ACL) injuries in adults are frequently accompanied by meniscal and articular cartilage damage. However, little is known regarding the association, if any, between physical maturity, hypermobility, or bone bruising and these associated injuries in skeletally immature patients with ACL tears. PURPOSE: To determine if physical maturity, hypermobility, and/or bone bruising is associated with concomitant meniscal and articular cartilage injury in skeletally immature patients with ACL tears. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: At 10 institutions in the United States, consecutive skeletally immature patients with complete ACL tears were enrolled between January 2016 and June 2020. Univariable and multivariable logistic regression analysis was used to assess the effect of variables on the likelihood of articular cartilage and meniscal injury. RESULTS: A total of 748 patients were analyzed. Of these, 85 patients (11.4%) had articular cartilage injuries. These patients had a higher bone age (13.9 vs 13.1 years; P = .001), a higher Tanner stage (P = .009), and increased height (162.9 vs 159.9 cm; P = .03) and were heavier (57.8 vs 54.0 kg; P = .02). For each additional Tanner stage, the odds of articular cartilage injury increased approximately 1.6 times (P < .001). Of the total patients, 423 (56.6%) had meniscal tears. Those with meniscal tears were older (12.6 vs 12.0 years; P < .001), had a higher bone age (13.5 vs 12.8 years; P < .001), had a higher Tanner stage (P = .002), had increased height (162.2 vs 157.6 cm; P < .001), and were heavier (56.6 vs 51.6 kg; P < .001). For each additional Tanner stage, the odds of a meniscal tear increased approximately 1.3 times (P < .001). No association was detected between hypermobility or bone bruising and the likelihood of articular cartilage or meniscal injury. Multivariable regression revealed that increasing Tanner stage was associated with an increasing risk of articular cartilage injury, while weight was associated with an increasing risk of meniscal injury. CONCLUSION: Increasing physical maturity is associated with increased risks of concomitant articular cartilage and meniscal injury in skeletally immature patients with ACL tears. Hypermobility and bone bruising are not associated with articular cartilage or meniscal injury, suggesting that physical maturity, rather than ligamentous laxity, is the primary risk factor for associated injuries in skeletally immature patients with an ACL tear.

Isolated Posterior Lateral Meniscofemoral Ligament Tears Show Greater Meniscal Extrusion in Knee Extension, and Isolated Posterior Lateral Meniscal Root Tears Show Greater Meniscal Extrusion at 30° Using Ultrasound: A Cadaveric Study.

PURPOSE: To quantify the effects that posterior meniscofemoral ligament (pMFL) lesions have on lateral meniscal extrusion (ME) both with and without concomitant posterior lateral meniscal root (PLMR) tears and describe how lateral ME varied along the length of the lateral meniscus. METHODS: Ultrasonography was used to measure ME of human cadaveric knees (n = 10) under the following conditions: control, isolated pMFL sectioning, isolated PLMR sectioning, pMFL+PLMR sectioning, and PLMR repair. ME was measured anterior to the fibular collateral ligament (FCL), at the FCL, and posterior to the FCL in both unloaded and axially loaded states at 0° and 30° of flexion. RESULTS: Isolated and combined pMFL and PLMR sectioning consistently demonstrated significantly greater ME when measured posterior to the FCL compared with other image locations. Isolated pMFL tears demonstrated greater ME at 0° compared with 30° of flexion (P < .05), whereas isolated PLMR tears demonstrated greater ME at 30° compared with 0° of flexion (P < .001). All specimens with isolated PLMR deficiencies demonstrated greater than 2 mm of ME at 30° flexion, whereas only 20% of specimens did so at 0°. When the pMFL was sectioned following an isolated PLMR tear, there was a significant increase in ME at 0° (P < .001). PLMR repair after combined sectioning restored ME to levels similar to that of controls in all specimens when measured at and posterior to the FCL (P < .001). CONCLUSIONS: The pMFL protects against ME primarily in full extension, whereas the presence of ME in the setting of PLMR injuries may be better appreciated in knee flexion. With combined tears, isolated repair of the PLMR can restore near-native meniscus position. CLINICAL RELEVANCE: The stabilizing properties of intact pMFL may mask the presentation of PLMR tears and delay appropriate management. Additionally, the MFL is not routinely assessed during arthroscopy due to difficult visualization and access. Understanding the ME pattern of these pathologies in isolation and combination may improve detection rates so that the source of patients' symptoms can be addressed to satisfaction.

Meniscal Ramp Lesions in Adolescent Patients Undergoing Primary Anterior Cruciate Ligament Reconstruction: Significance of Imaging and Arthroscopic Findings.

BACKGROUND: Meniscal ramp lesions are associated with anterior cruciate ligament (ACL) injuries and may affect knee stability when left untreated. The diagnostic accuracy of magnetic resonance imaging (MRI) to identify this meniscocapsular injury of the posterior horn of the medial meniscus remains poor, and the arthroscopic findings require vigilance. PURPOSE: To determine the concordance of arthroscopic and MRI findings to better identify the presence of a ramp lesion in children and adolescent patients undergoing primary ACL reconstruction. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: Patients aged <19 years who underwent primary ACL reconstruction at a single institution between 2020 and 2021 were included. Two cohorts were developed by the presence of a ramp lesion arthroscopically. Basic patient descriptive data, preoperative imaging (radiologist assessment and independent reviewer assessment), and concomitant arthroscopic findings at the time of ACL reconstruction were recorded. RESULTS: An overall 201 adolescents met criteria with a mean age of 15.7 years (range, 6.9-18.2) at the time of injury. A ramp lesion was identified in 14% of patients (28 children). No differences were detected between cohorts with regard to age, sex, body mass index, weeks from injury to MRI, or weeks from injury to surgery (P > .15). The primary predictor of an intraoperative ramp lesion was the presence of medial femoral condylar striations, with an adjusted odds ratio of 722.2 (95% CI, 59.5-8768.2; P < .001); the presence of a ramp lesion on MRI had an adjusted odds ratio of 11.1 (95% CI, 2.2-54.8; P = .003). Patients with neither a ramp lesion on MRI nor medial femoral condylar striations had a 2% rate (2/131) of ramp lesion; those with either of the significant risk factors had a 24% rate (14/54). All patients with both risk factors (100%; n = 12) had a ramp lesion noted on intraoperative examination. CONCLUSION: The concordance of medial femoral condylar chondromalacia, particularly striations, noted during arthroscopy and posteromedial tibial marrow edema on MRI with or without direct evidence of posterior meniscocapsular pathology should increase suspicion for the presence of a ramp lesion in adolescents undergoing ACL reconstruction.

Bucket-Handle Meniscus Tear Management With Meniscectomy Versus Repair Correlates With Patient, Socioeconomic, and Hospital Factors.

INTRODUCTION: Bucket-handle meniscus tears are common knee injuries that are often treated surgically with meniscectomy or meniscal repair. Although clinical factors may influence the choice of one treatment approach over the other, the influence of patient, socioeconomic, and hospital factors remains poorly characterized. This study aimed to estimate the relative nationwide utilization of these two procedures and delineate a variety of factors that are associated with the selection of one treatment approach over the other. METHODS: Meniscal repair and meniscectomy procedures conducted for isolated bucket-handle meniscus tears in 2016 and 2017 were identified in the Nationwide Ambulatory Surgery Sample database. Cases were weighted using nationally representative discharge weights. Univariate analyses and a multivariable logistic regression model were used to compare patient, socioeconomic, and hospital factors associated with meniscal repair versus meniscectomy. RESULTS: In total, 12,239 cases were identified, which represented 17,236 cases after weighting. Of these, meniscal repair was conducted for 4,138 (24.0%). Based on the logistic regression model, meniscal repair was less likely for older and sicker patients. By contrast, several factors were associated with markedly higher odds of undergoing meniscal repair compared with meniscectomy. These included urban teaching hospitals; geographic location in the midwest, south, and west; and higher median household income. DISCUSSION: Using a large nationally representative cohort, the current data revealed that only 24.0% of surgically treated bucket-handle meniscus tears were treated using repair. Identification of patient, socioeconomic, and hospital factors differentially associated with meniscal repair suggest that other factors may systematically influence surgical decision-making for this patient population. Surgeons should be conscious of these potential healthcare disparities when determining the optimal treatment for their patients. LEVEL OF EVIDENCE: Level III.

Higher Grit Scores Are Associated With Earlier Increases in Knee Flexion Following Anterior Cruciate Ligament Reconstruction With Meniscus Repair in Pediatric Patients.

BACKGROUND: The Grit Scale is used to measure grit, defined by Duckworth and colleagues as the disposition to show perseverance and passion for long-term goals. It has been shown that psychological factors like motivation, coachability, and coping with adversity are correlated with faster readiness for return to sport (RTS) in patients undergoing anterior cruciate ligament reconstruction (ACLR). This study investigates the association between pediatric patients' baseline grit scores and; preoperative Patient-reported Outcomes Measurement Information System (PROMIS) Pain scores and the recovery of range of motion (ROM) after ACLR. The investigators hypothesized that higher preoperative grit scores would predict lower preoperative pain scores and earlier return of knee ROM in patients undergoing ACLR. METHODS: This is a retrospective cohort study. Pediatric patients who underwent primary ACLR were assigned the pediatric Grit Scale. Patients were subdivided by meniscal procedures due to differences in postoperative protocols. ACLR alone or with meniscectomy (ACLR ± meniscectomy) were grouped together and ACLR with meniscal repair (ACLR + meniscus repair) represented the other cohort. Patients above the 50th grit percentile were considered "high grit". Patients below the 50th percentile were considered "low grit". Baseline PROMIS pain intensity and interference were collected. ROM was compared by grit cohort using the Mann-Whitney U test with a significance threshold of P ≤ 0.05. RESULTS: A total of 58 patients undergoing ACLR were analyzed: 20 ACLR ± meniscectomy and 38 ACLR + meniscus repair. The mean age was 15.0 ± 2.1 years with 41.4% of participants identifying as females. No significant difference was noted between baseline PROMIS pain intensity and interference and grit score ( P = 0.82, P = 0.91, respectively). Three months postoperatively, for those in the ACLR + meniscus repair cohort, low grit ROM was 130 degrees (interquartile range = 10 degrees), whereas high grit ROM was 135 degrees (interquartile range = 8 degrees) ( P = 0.006). CONCLUSIONS: This study found no differences in pain scores at presentation between grit cohorts but found that patients with grit scores below the 50th percentile undergoing ACLR + meniscus repair have 5 degrees less total ROM at 3 months compared with those with high grit scores. Quicker ROM recovery in patients with high grit may be a leading indicator of these patients' likelihood to achieve other postoperative milestones and meet criteria for RTS more quickly; the relationship between grit and readiness for RTS should be further investigated. LEVEL OF EVIDENCE: Level IV; retrospective cohort study.

Lateral-medial asymmetry of posterior tibial slope and small lateral tibial plateau articular surface depth are morphological factors of lateral meniscus posterior root tears in ACL-injured patients.

PURPOSE: To investigate whether knee morphological features, patient characteristics, and intraoperative findings are associated with a lateral meniscus (LM) posterior root tear (LMPRT) in anterior cruciate ligament (ACL) injuries with the integrated data from two academic centres. METHODS: This retrospective study used registry data acquired prospectively at two academic centres. Patients with ACL reconstruction (ACLR) with LMPRT and no other LM injury were selected (LMPRT group) from each database. The control group included patients who underwent ACLR without LM tears. Patients were matched to the LMPRT group according to age and gender (1:1). Morphological factors evaluated on preoperative magnetic resonance image scans included lateral femoral condyle (LFC) anterior-posterior diameter, height, and depth; lateral tibial plateau (LTP) articular surface (AS) depth and sagittal plane depth; and lateral and medial posterior tibial slopes (PTSs). LFC height and depth ratios, LTP AS depth and sagittal plane depth ratios, and lateral-to-medial slope asymmetry were computed from previous measurements. Patient characteristics and intraoperative findings were extracted and compared between both groups. RESULTS: The study included 252 patients (126 in each group). The lateral-medial asymmetry of PTS was greater in the LMPRT group (1.2° vs 0.3°, p < 0.05), and the LTP AS depth was smaller in the LMPRT group (31.4 mm vs 33.2 mm, p < 0.01). There were no differences in LFC morphology between the control and LMPRT groups. Pivot shift grade (p < 0.05), percentage of complete ACL tears (p < 0.05), and medial meniscus ramp lesions (p < 0.05) were significantly higher in the LMPRT group. CONCLUSION: LMPRT was associated with significantly increased lateral-medial asymmetry of PTS and significantly smaller LTP AS depth. LMPRT was also associated with an increase in the preoperative pivot shift grade and the presence of a medial meniscus ramp lesion. These morphological characteristics are rather simple to measure and would serve as helpful indicators to preoperatively detect LMPRT, which is frequently challenging to diagnose preoperatively. LEVEL OF EVIDENCE: Level III.

Development and Analysis of Mouse Medial Meniscus Posterior Root Tear Model.

Medial meniscus posterior root tears (MMPRT) are often associated with osteoarthritis (OA) progression and subchondral bone insufficiency fractures. This study aimed to develop the first MMPRT mouse model. The MMPRT model was created by sectioning the medial meniscus posterior root of 12-week-old CL57BL/6J male mice under stereomicroscopic observation. The sham operation and the destabilization of the medial meniscus (DMM) model groups were also created. OA progression and subchondral bone changes were evaluated histologically using the Osteoarthritis Research Society International (OARSI) subchondral bone scoring system at 2, 4, 8, and 12 weeks after surgery. Microcomputed tomography (µCT) was performed to evaluate the presence of insufficient fractures. OA progression and medial meniscus extrusion were observed in the MMPRT and DMM models 12 weeks after surgery. OA progressed in both models during the time course, without a significant difference in the OARSI score between the two groups. The subchondral bone score was significantly higher at 12 weeks than at 2 and 4 weeks in the MMPRT group, while no significant difference was found between the two groups. In the µCT analysis, destruction of the medial tibial plateau was observed in 4/40 knees, while none were observed in the DMM group. Of the four knees, destruction of the medial femoral condyle was also observed in three knees. Characteristic pathological changes were observed in the mouse MMPRT model. The mouse MMPRT model may be useful for investigating pathological changes after MMPRT.

Increased Time to Surgery After Anterior Cruciate Ligament Tear in Female Patients Results in Greater Risk of Medial Meniscus Tear: A Study of 489 Female Patients.

PURPOSE: This study assessed the incidence of meniscal tears in anterior cruciate ligament (ACL)-deficient knees, considering the time between injury and reconstruction in a large sample of female patients. Furthermore, we evaluated whether the rate of meniscal repair or meniscectomy was affected by age and body mass index (BMI). METHODS: The medical records of 489 patients who underwent ACL-reconstructive surgery between January 2011 and April 2021 were analyzed to collect data on the prevalence of meniscal tears, surgical timing, patient age, and BMI. Logistic regression was performed to estimate the association between the prevalence of meniscal tears and the independent variables of surgical timing, age, and BMI. RESULTS: Between 24 and 60 months after their injury, female patients showed a statistically significant increase in the presence of associated meniscal lesions when compared with ACL reconstruction performed earlier (odds ratio [OR] of 3.11; 95% 1.06-9.10 confidence interval [CI]), especially for medial meniscal tears, with an OR of 1.94 (95% CI 1.23-3.05, P = .004) between 12 and 24 months. There is a statistically significant difference after 12 months in the rate of meniscal suturing for medial meniscus tears (OR 3.30; CI 1.37-7.91 P = .007). Increasing age was associated with a greater prevalence of meniscal tears up to 30-50 years, but there was no clear association between BMI and associated lesions other than a greater rate of meniscectomies. CONCLUSIONS: In female patients who experienced an ACL injury, a delay in surgery greater than 12 months is associated with a gradual increase in the risk of nonrepairable medial meniscal tear; this risk becomes statistically significant after 24 months. A high BMI does not seem to have relevance in the onset of associated lesions in women but results in a greater rate of meniscectomies compared with meniscal sutures, whereas age between 30 and 50 years is associated with a greater risk of associated injuries. LEVEL OF EVIDENCE: III, retrospective comparative prognostic trial.

Posteromedial tibial plateau bone bruises are associated with medial meniscal ramp lesions in patients with concomitant anterior cruciate ligament ruptures: a systematic review & meta-analysis.

OBJECTIVE: To determine if posteromedial tibial plateau (PMTP) bone bruising on pre-operative MRI is significantly associated with a ramp lesion identified during arthroscopy in patients with concomitant ACL ruptures. METHODS: PubMed, CINAHL, Scopus, Web of Sciences, EMBASE, and Cochrane Library were searched systematically for studies that investigated the association between PMTP bone bruises on preoperative MRI and ramp lesions confirmed during arthroscopy. Eight studies met inclusion criteria. The Methodological Index for Nonrandomized Studies (MINORS) checklist was used to assess quality. A meta-analysis was performed to analyze odds of a ramp lesion after PMTP bone bruising identified on magnetic resonance imaging (MRI). Publication bias was assessed by funnel plot and Egger's linear regression test. RESULTS: There are 2.05 greater odds of medial meniscal ramp lesions in patients with an ACL rupture when PMTP bone bruising is found on preoperative MRI (95% CI, 1.29-3.25; p = 0.002). Heterogeneity of the pooled studies may be substantial (I2 = 65%; p = 0.006). Funnel plot analysis and Egger's linear regression test (p > 0.5) determined no publication bias among the studies included in the meta-analysis. CONCLUSION: Patients with acute ACL injuries and PMTP bone bruising on MRI have 2.05 times greater odds of a concomitant medial meniscal ramp lesion than those without this bone bruise pattern.

Steep posterior slope of the medial tibial plateau and anterior cruciate ligament degeneration contribute to medial meniscus posterior root tears in young patients.

PURPOSE: Medial meniscus posterior root tears (MMPRTs) occur most frequently in middle-aged and older adults. However, this serious condition can also occur in younger patients. The purpose of this study was to compare anterior cruciate ligament (ACL) degeneration and sagittal medial tibial slope in young adults with and without MMPRT. METHODS: Eighteen healthy volunteers, 18 young patients (20-49 years of age), and 30 middle-aged and older patients (50-70 years of age) with MMPRT repair were included in the study. Sex, body mass index (BMI), femorotibial angle, ACL degeneration, and medial tibial slope angle were compared among the groups. ACL degeneration and medial tibial slope angle were assessed using magnetic resonance imaging. RESULTS: In the healthy volunteer group, the young patient group, and the older patient group, the medial tibial slopes were 3.5° ± 1.4°, 6.1° ± 2.7°, and 7.2° ± 1.9°, respectively, and the ACL degeneration rates were 5.6%, 38.9%, and 43.3%, respectively. Young patients with MMPRT had significantly steeper medial tibial slopes and ACL degeneration compared to those of the healthy volunteers (P < 0.05). The parameters of young patients were similar to those of older patients with MMPRT. In the multivariate logistic regression analysis, BMI, medial tibial slope, and ACL degeneration were significantly associated with MMPRT in young patients. CONCLUSION: BMI, steep medial tibial slope, and ACL degeneration contribute to MMPRT development in younger patients. LEVEL OF EVIDENCE: Level III.

High prevalence of meniscal ramp lesions in anterior cruciate ligament injuries.

PURPOSE: To evaluate the prevalence of and factors associated with meniscal ramp lesions on magnetic resonance imaging (MRI) in patients with anterior cruciate ligament (ACL) injuries. METHODS: Data from the Natural Corollaries and Recovery after ACL injury multicentre longitudinal cohort study (NACOX) were analysed. Only patients who underwent MRI were included in this study. All MRI scans were reviewed by an orthopaedic knee surgeon and a musculoskeletal radiologist. The patients were divided into two groups, those with and without ramp lesions according to MRI findings. Univariable and stepwise forward multiple logistic regression analyses were used to evaluate patient characteristics (age, gender, body mass index, pre-injury Tegner activity level, activity at injury) and concomitant injuries on MRI (lateral meniscus, medial collateral ligament [MCL], isolated deep MCL, lateral collateral ligament, pivot-shift-type bone bruising, posteromedial tibial [PMT] bone bruising, medial femoral condyle bone bruising, lateral femoral condyle [LFC] impaction and a Segond fracture) associated with the presence of meniscal ramp lesions. RESULTS: A total of 253 patients (52.2% males) with a mean age of 25.4 ± 7.1 years were included. The overall prevalence of meniscal ramp lesions was 39.5% (100/253). Univariate analyses showed that contact sports at ACL injury, pivot-shift-type bone bruising, PMT bone bruising, LFC impaction and the presence of a Segond fracture increased the odds of having a meniscal ramp lesion. Stepwise forward multiple logistic regression analysis revealed that the presence of a meniscal ramp lesion was associated with contact sports at ACL injury [odds ratio (OR) 2.50; 95% confidence intervals (CI) 1.32-4.72; P = 0.005], pivot-shift-type bone bruising (OR 1.29; 95% CI 1.01-1.67; P = 0.04), PMT bone bruising (OR 4.62; 95% CI 2.61-8.19; P < 0.001) and the presence of a Segond fracture (OR 4.38; 95% CI 1.40-13.68; P = 0.001). CONCLUSION: The overall prevalence of meniscal ramp lesions in patients with ACL injuries was high (39.5%). Contact sports at ACL injury, pivot-shift-type bone bruising, PMT bone bruising and the presence of a Segond fracture on MRI were associated with meniscal ramp lesions. Given their high prevalence, meniscal ramp lesions should be systematically searched for on MRI in patients with ACL injuries. Knowledge of the factors associated with meniscal ramp lesions may facilitate their diagnosis, raising surgeons' and radiologists' suspicion of these tears. LEVEL OF EVIDENCE: III.