Early Surgery Versus Exercise Therapy and Patient Education for Traumatic and Nontraumatic Meniscal Tears in Young Adults-An Exploratory Analysis From the DREAM Trial.

OBJECTIVE: To compare the effect of early meniscal surgery versus exercise and education with the option of later surgery on pain, function, and quality of life in young patients with a meniscal tear, taking symptom onset into account. DESIGN: Randomized controlled trial. METHODS: In a randomized controlled trial (the "Danish RCT on Exercise versus Arthroscopic Meniscal surgery for young adults" [DREAM] trial), 121 patients aged 18-40 years with a magnetic resonance imaging-verified meniscal tear were randomized to surgery or 12 weeks of supervised exercise and patient education. For this exploratory study, the analyses were stratified by symptom onset (traumatic/nontraumatic). The main outcome was the difference in change after 12 months in the mean score of 4 Knee injury and Osteoarthritis Outcome Score subscales (KOOS4) covering pain, symptoms, function in sport and recreation, and quality of life. RESULTS: Forty-two patients (69%) in the exercise therapy group and 47 (78%) in the surgery group were categorized as having a traumatic tear. We observed no difference in change in the KOOS4 after 12 months between the 2 treatment groups for either traumatic tears (18.8 versus 16.0 in the surgery versus exercise therapy groups; adjusted mean difference, 4.8 [95% confidence interval, -1.7 to 11.2]) or nontraumatic tears (20.6 versus 17.3 in the surgery versus exercise therapy groups; adjusted mean difference, 7.0 [95% confidence interval, -3.7 to 17.7]). CONCLUSION: In patients with traumatic and nontraumatic meniscus tears, early meniscal surgery did not appear superior to exercise and education in improving pain, function, and quality of life after 12 months. Further research is needed to confirm the clinical applicability of these findings. J Orthop Sports Phys Ther 2024;54(5):1-10. Epub 22 February 2024. doi:10.2519/jospt.2024.12245.

Physical Therapist Interventions Versus or Combined With Surgical Treatment in Nontraumatic Degenerative Meniscal Pathology: A Systematic Review and Network Meta-Analysis.

OBJECTIVE: This study aimed to synthesize the evidence from randomized clinical trials in people with nontraumatic degenerative meniscal pathology by comparing physical therapist interventions versus or combined with arthroscopic partial meniscectomy (APM). METHODS: Seven electronic databases were searched. Methodological quality was evaluated using the Physiotherapy Evidence Database scale. Data synthesis was performed with random-effects network meta-analysis, and results were summarized using the standardized mean differences. RESULTS: From 2103 studies, 10 randomized clinical trials comprising 1411 individuals were included. Ninety percent of the selected randomized clinical trials were classified as good quality according to the Physiotherapy Evidence Database scale. All interventions (physical therapist interventions, APM, and APM plus physical therapist interventions) showed reduced pain and physical impairments at 3-month follow-up. However, when a physical therapist intervention was included, greater reductions in pain at rest (APM vs physical therapist interventions: 0.73 [95% CI = 0.20 to 1.26]; APM vs APM plus physical therapist interventions: 0.59 [95% CI = 0.15 to 1.03]) and greater increases in the strength of knee extensor muscles (APM vs physical therapist interventions: 0.44 [95% CI = 0.07 to 0.80]; APM vs APM plus physical therapist interventions: 0.73 [95% CI = 0.29 to 1.16]) were observed at 3 months. By contrast, no differences were found between treatments beyond 3 months. CONCLUSION: Physical therapist interventions based on exercise programs demonstrate superior short-term outcomes in pain reduction and knee extensor strength compared to surgical treatment. IMPACT: For nontraumatic degenerative meniscal pathology, conservative treatment utilizing a physical therapist intervention approach should be prioritized as the first choice over surgical treatment. It offers comparable or superior short-term pain reduction and strength improvements, with a lower risk of side effects. In cases where surgery is deemed necessary, including postsurgical, physical therapist interventions are highly recommended to enhance muscle strength and alleviate pain.

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.

Treatment strategies for meniscal lesions: from past to prospective therapeutics.

Menisci play an important role in the biomechanics of knee joint function, including loading transmission, joint lubrication, prevention of soft tissue impingement during motion and joint stability. Meniscal repair presents a challenge due to a lack of vascularization that limits the healing capacity of meniscal tissue. In this review, the authors aimed to untangle the available treatment options for repairing meniscal tears. Various surgical procedures have been developed to treat meniscal tears; however, clinical outcomes are limited. Consequently, numerous researchers have focused on different treatments such as the application of exogenous and/or autologous growth factors, scaffolds including tissue-derived matrix, cell-based therapy and miRNA-210. The authors present current and prospective treatment strategies for meniscal lesions.

One of the most common knee injuries, especially in athletes, is a meniscal tear. There are two wedge-shaped pieces of fibrocartilage that act as shock absorbers between the thighbone and shinbone (menisci). The menisci help to transmit weight from one bone to another and play an important role in knee stability. The challenge for researchers and clinicians is to repair meniscal injuries, despite the lack of vascularization. The authors discuss the available approaches for repairing meniscal tears. Non surgical and surgical procedures are reviewed, clarifying their clinical outcomes. Other approaches to tissue engineering are also discussed. Using the patient's cells may be a potential strategy to repair meniscal injuries and improve the durability of the knee joint.

Meniscus Root Tears: A Clinical Review.

ABSTRACT: Meniscus root tears are important to recognize early given their potentially devastating consequences on joint health. This injury results in the lost ability of the meniscus to transfer axial loads into hoop stress; therefore, it is functionally equivalent to a complete meniscectomy. This causes rapid progression of osteoarthritis and increased need to total knee arthroplasty in a previously healthy joint. Despite these consequences, root tears have only been discussed in the orthopedic literature in the last 10 to 15 years and have not been routinely integrated into nonoperative sports medicine education. It is important for all nonoperative sports medicine providers to properly diagnose and triage this injury early in its course to maximize joint preservation efforts. The goal of this manuscript is to review the anatomy, presentation, natural history, imaging, and treatment options for meniscal root tears.

Comparative clinical outcomes of different therapies for traumatic meniscal tears in adults: A protocol for systematic review and network meta-analysis.

BACKGROUND: Meniscus tears are usually classified as degenerative or traumatic tears according to their pathogenesis. At present, traumatic meniscal tears are generally believed to have high healing potential. In recent years, multiple treatments have been described for traumatic meniscal tears, such as the inside-out technique, outside-in technique, all-inside technique, biological augmentation of meniscal repair, meniscectomy, and non-surgical treatment. However, the functional recovery of the knee joint and healing of the meniscus after treatment are quite different from the results reported in the literature, which requires more reliable evidence-based medical findings. This study will evaluate evidence from multiple types of research comparing different therapies for traumatic meniscal tears in adults. METHODS: We will search the EMBASE, Cochrane Library (the Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials [CENTRAL], Cochrane Methodology Register), PubMed, Web of Science (Science and Social Science Citation Index), China Knowledge Network, CBM, Wanfang data, and VIP electronic databases from their inception to August 10, 2021, with no language restrictions. We will also manually search Baidu and Google Scholar to identify randomized controlled studies, non-randomized controlled studies, and cohort studies on the treatment of traumatic meniscal tears. Two researchers will independently screen the literature, extract the data, and evaluate the quality of the studies. Software programs, including Microsoft Access, Excel, Stata (Version 15), WinBUGS (Version 1.4.3), and ADDIS (Version 1.16.8), were used to analyze and manipulate the data. RESULTS: In this study, the main outcomes were physical function and healing rate, based on the Western Ontario and McMaster Universities Osteoarthritis Index, Lysholm Knee Scoring Scale, Knee Injury and Osteoarthritis Outcome Score, Functional Recovery Scale, and clinical healing rate. The secondary indexes included total cost, cost-effectiveness ratio, incremental cost-effectiveness ratio, Tegner activity scale score, visual analogue scale, numerical rating scale, and meniscal tear complications. CONCLUSIONS: This systematic review will provide reliable evidence-based findings for the clinical application of different therapies for traumatic meniscal tears in adults.

Artropatía enteropática y fractura de platillos tibiales. Reporte de un caso / Enteropathic Arthropathy and tibial plateau fracture. Report of a case

Introducción: la artropatía enteropática representa una manifestación derivada de complicaciones inflamatorias intestinales. Presentación del caso: paciente de 53 años de edad, de piel blanca, femenina, que sufrió caída de sus pies, con trauma en rodilla izquierda que le ocasionó fractura de meseta tibial izquierda. Discusión: los estudios radiológicos fueron positivos y confirman el diagnóstico de la artropatía enteropática y fractura de platillos tibiales, se aplicaron pautas de tratamientos integradores funcionales. Conclusiones: con los tratamientos el paciente reportó efectos beneficiosos, se lograron los objetivos propuestos en la rehabilitación, así como la incorporación de la paciente a la sociedad con un mínimo de discapacidad e independencia(AU)

Introduction: enteropathic arthropathy represents a manifestation derived from intestinal inflammatory complications. Case presentation: 53-year-old white-skinned female patient who suffered a fall from her feet, with trauma to the left knee that caused a fracture of the left tibial plateau. Discussion: the radiological studies were positive and confirm the diagnosis of enteropathic arthropathy and tibial plateau fractures, functional integrative treatment guidelines were applied. Conclusions: with the treatments the patient reported beneficial effects, the objectives proposed in the rehabilitation were achieved, as well as the incorporation of the patient into society with a minimum of disability and independence(EU)

Arthroscopic Partial Meniscectomy versus Physical Therapy for Degenerative Meniscal Tear: a Systematic Review.

BACKGROUND: Meniscal tears are commonly observed in patients with knee osteoarthritis (OA), however, clinical significance of such lesions detected by magnetic resonance imaging is in many cases unclear. This study aimed to determine the clinical effectiveness of arthroscopic partial meniscectomy (APM) compared with non-operative care in patients with knee OA. METHOD: We used existing systematic reviews with updates of latest studies. Three randomized controlled studies were selected, where two studies compared the effects of APM plus physical therapy (PT) with PT alone and one compared APM alone and PT alone. While 1 study exclusively included OA patients, 2 studies included 21.1 and 12% of patients with no radiographic OA. Patients with knee locking were unanimously excluded. RESULTS: Upon comparison of APM plus PT and PT alone, there was no significant difference observed in knee function, physical activity, or adverse events. Knee pain was observed to be significantly lower in the APM plus PT group at 6 months, but there was no difference between the two groups at 12 and 24 months. With respect to the comparison between APM alone and PT alone, PT was non-inferior based on the criteria for knee function during 24 months; however, knee pain was significantly reduced in the APM alone group. CONCLUSIONS: Our study showed that knee pain was significantly improved in the APM group compared to non-operative care group at 6 months and over 24 months. Our result was based on only 3 randomized controlled trials (RCTs) revealing a significant knowledge gap, hence demanding more high-quality RCTs in OA patients. TRIAL REGISTRATION: PROSPERO Identifier: CRD42020215965.

Effects of Platelet-Rich Plasma and Bone Marrow Mesenchymal Stem Cells on Meniscal Repair in the White-White Zone of the Meniscus.

OBJECTIVE: To investigate the role of autologous platelet-rich plasma (PRP) on the repair of meniscal white-white zone injury through promoting the proliferation of canine bone marrow-derived mesenchymal stem cells (BMSCs). METHODS: A total of 24 beagle dogs were selected to construct meniscal white-white zone injury models in both lateral knee joints. All subjects were divided into four groups: control, BMSCs, PRP, and PRP + BMSCs. Immunohistochemistry was applied in the expression detection of type I and type II collagens. HE staining and methylene blue staining were performed to observe the injury of cartilage of lateral femoral condyle in each group. ELISA was used to detect the osteopontin (OPN) content in cartilage of lateral femoral condyle. HE staining and magnetic resonance imaging (MRI) were used to observe the healing of meniscus in each group. Outcome measures include the expression of OPN in the synovial fluid of knee joint, the expression of type I collagen and type II collagen, the healing of meniscus injury, and the damage degree of lateral femoral condyle cartilage. RESULTS: Compared with the control group, the expressions of type I and type II collagens were enhanced in the PRP group and the PRP + BMSCs group. Compared with 1 week before modeling, the expression of OPN was elevated in the control group and the BMSCs group at 3 weeks after modeling. There were no significant differences in the above indicators between the PRP group and the PRP + BMSCs group. According to MRI and pathological section after HE staining, meniscal healing in the PRP group and the PRP + BMSCs group was significantly improved as compared to that of the control group and the BMSCs group (all P < 0.05), and there was no significant difference between the PRP group and the PRP + BMSCs group (P > 0.05). All subjects were divided into the non-healing group and the healing group in accordance with the HE staining results in previous experiment. The injury of cartilage of lateral femoral condyle was significantly heavier in the non-healing group than that in the healing group. CONCLUSION: The application of PRP alone or in combination with BMSCs could promote the clinical healing rate of meniscal white-white zone injury.

In Vivo Studies of Mesenchymal Stem Cells in the Treatment of Meniscus Injury.

This review summarizes the literature of preclinical studies and clinical trials on the use of mesenchymal stem cells (MSCs) to treat meniscus injury and promote its repair and regeneration and provide guidance for future clinical research. Due to the special anatomical features of the meniscus, conservative or surgical treatment can hardly achieve complete physiological and histological repair. As a new method, stem cells promote meniscus regeneration in preclinical research and human preliminary research. We expect that, in the near future, in vivo injection of stem cells to promote meniscus repair can be used as a new treatment model in clinical treatment. The treatment of animal meniscus injury, and the clinical trial of human meniscus injury has begun preliminary exploration. As for the animal experiments, most models of meniscus injury are too simple, which can hardly simulate the complexity of actual meniscal tears, and since the follow-up often lasts for only 4-12 weeks, long-term results could not be observed. Lastly, animal models failed to simulate the actual stress environment faced by the meniscus, so it needs to be further studied if regenerated meniscus has similar anti-stress or anti-twist features. Despite these limitations, repair of the meniscus by MSCs has great potential in clinics. MSCs can differentiate into fibrous chondrocytes, which can possibly repair the meniscus and provide a new strategy for repairing meniscus injury.

Ultrasound-Guided Meniscal Injection of Autologous Growth Factors: A Brief Report.

Meniscal degeneration is a common finding even in young patients' knees, and it is regarded as a predictor for the onset of early osteoarthritis (OA). When symptomatic, it represents a challenge since arthroscopic surgery provides unpredictable results: recent evidence has shown that partial meniscectomy is not better than conservative management up to 2 years of follow-up, and the removal of meniscal tissue may accelerate OA progression toward OA. Intra-articular injection of corticosteroids or hyaluronic acid may help in providing temporary symptomatic relief, but no influence should be expected on the quality of the meniscal tissue. Biologic agents have been adopted to treat a variety of degenerative musculoskeletal pathologies, and the use of platelet-derived growth factors (GFs) has become routine. Preclinical studies have documented that platelet-derived GFs may play a beneficial role in stimulating meniscal repair and regeneration by triggering anabolic pathways and stimulating local mesenchymal stem cells from synovium. Furthermore, also mechanical stimulation (e.g., arthroscopic trephination or percutaneous needling) in the red-red or red-white zone may further promote tissue healing. The purpose of the present brief report is to describe the clinical outcomes at 18 months' follow-up in a cohort of patients affected by symptomatic medial meniscus degeneration and treated by percutaneous needling plus intra- and perimeniscal injection of autologous conditioned plasma (ACP). The procedure was shown to be safe and provided significant pain reduction and improvement in subjective scores. This treatment option deserves further investigation in a comparative setting, to establish whether it could offer advantage over isolated intra-articular injections.

Meniscal Injuries: Mechanism and Classification.

Meniscal tears may be managed through conservative physical therapy and nonsteroidal anti-inflammatory medications or operative intervention. Meniscal repair is superior to partial meniscectomy with better functional outcomes and less severe degenerative changes over time. Surgical advances in operative techniques, modern instrumentation and biological enhancements collectively improve healing rates of meniscal repair. However, failed repair is not without consequences and can negative impact patient outcomes. Therefore, it is imperative for surgeons to have a thorough understanding of the vascular zones and biomechanical classifications of meniscal tears in order to best determine the most appropriate treatment.

The Epidemiology of Meniscus Injury.

Meniscus surgery is one of the most commonly performed orthopedic procedures worldwide. Modifiable risk factors for meniscus injury include body mass index, participation in athletics and occupation. Nonmodifiable risk factors include age, sex, lower extremity alignment, discoid meniscus, ligamentous laxity, and biconcave tibial plateau. Conditions commonly associated with meniscal injury are osteoarthritis, anterior cruciate ligament injury, and tibial plateau fractures. Tear type and location vary by patient age and functional status. Surgical management of meniscus injury is typically cost-effective in terms of quality-adjusted life years. The purpose of this review is to provide an overview of meniscal injury epidemiology by summarizing tear types and locations, associated conditions, and factors that increase the risk for meniscal injury. The economic burden of meniscus injury and strategies to prevent injury to the meniscus are also reviewed.

Meniscus Repair Techniques.

The menisci play a vital role in maintaining knee function and protecting the chondral surfaces. Acute and chronic tears are common injuries among both young athletes and older patients with early degenerative changes. The progression of physiological derangement and chondral injury after meniscus injury and meniscectomy have prompted interest in expanding meniscus repair techniques. Recent literature encourages an attempt at repair in tear patterns previously declared irreparable if the tissue quality allows. The orthopedic surgeon should understand the multitude of techniques available to them and be prepared to combine techniques to optimize the quality of their repair construct. While biological augmentation may show some promising early results, the quality of the current data precludes strong recommendations in their favor.

On a Trajectory for Success-9 in Every 10 People With a Degenerative Meniscus Tear Have Improved Knee Function Within 2 Years After Treatment: A Secondary Exploratory Analysis of a Randomized Controlled Trial.

OBJECTIVE: To identify trajectories of patient-reported knee function over 5 years in patients with degenerative meniscal tears, and to explore whether baseline characteristics were associated with trajectories of sport and recreational function. DESIGN: Prospective cohort study. METHODS: We conducted a secondary exploratory analysis of the Odense-Oslo Meniscectomy Versus Exercise randomized controlled trial. Patient-reported knee function was assessed with the Knee injury and Osteoarthritis Outcome Score (KOOS) at baseline, 3 months, 1 year, 2 years, and 5 years. We used group-based trajectory modeling to identify subgroups of patients who followed distinctive patterns of change. Multinomial logistic regression was used to examine the associations of patient demographics, knee function, and disease-related factors with KOOS sport and recreational function subscale trajectories. RESULTS: The analysis of data from a sample of 140 participants identified 3 trajectories for all KOOS subscales: (1) low, minimal improvement (10%-12% of the participants), (2) moderate, gradual improvement (20%-36%), and (3) high, early improvement (53%-70%). Baseline prognostic factors for deteriorating function in sport and recreational activities were higher body mass index, poorer mental health, greater knee pain, lower perceived knee function, poorer quadriceps and hamstrings muscle strength, poorer functional performance, more meniscal extrusion, and radiographic signs of knee osteoarthritis. CONCLUSION: We found 3 distinct trajectories of patient-reported knee function over 5 years: (1) low, minimal improvement, (2) moderate, gradual improvement, and (3) high, early improvement. Nine in every 10 participants improved at least gradually over 2 years after diagnosis of a degenerative meniscal tear. J Orthop Sports Phys Ther 2021;51(6):289-297. Epub 10 May 2021. doi:10.2519/jospt.2021.10025.

Age, activity level and meniscus injury, but not tear location, tibial slope or anterolateral ligament injury predict coping with anterior cruciate ligament injury.

INTRODUCTION: Early recognition of potential predictors on the success of conservative treatment of anterior cruciate ligament (ACL) is important, as appropriate treatment can be applied to each individual patient. The goal of this study is to assess the patient demographic and radiological parameters that predict coping with ACL injuries. METHODS: All patients presenting with a complete ACL injury between 2014 and 2018 at our clinic were included. The role of patient demographics (age, gender, activity level, meniscus injury and time from injury to clinic), and ACL tear location, bone bruises, tibial slope, and anterolateral ligament (ALL) injury were assessed on the success of conservative treatment using univariate and multivariate analyses. RESULTS: Sixty-five patients (32%) were copers and 141 (68%) were non-copers. Univariate analysis showed that copers were significantly older (40 vs. 27 years, P < 0.001), had lower preinjury activity level (Tegner 5.7 vs. 6.5, P < 0.001) and less often lateral meniscus tears (16% vs. 5%, P = 0.019) but not medial meniscus tears (17% vs. 14%, P = 0.609) than non-copers. Multivariate analysis revealed that increasing age (P < 0.001), Tegner level ≤ 6 (P = 0.003) and no meniscus injury (P = 0.045) were independent predictors of coping with ACL deficiency. CONCLUSIONS: Older age, participation in lower activity sports levels and absence of meniscus injury were predictive of coping with ACL deficiency, whereas there was no such role for tear location, tibial slope, lateral bone bruise presence, ALL injury or gender. These findings might help to identify potential copers and guide surgeons early in the optimal treatment for patients with ACL injury.

Stem cells application in meniscal tears: a systematic review of pre-clinical and clinical evidence.

OBJECTIVE: Conservative and surgical treatments for meniscal lesions are various and this field of orthopedic surgery is in continuous development. Stem cells represent one of the current options to stimulate meniscal healing. The present systematic review aimed at summarizing the state of art in the application of stem cells for the treatment of meniscal damage both at pre-clinical and clinical level. MATERIALS AND METHODS: The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed to perform this systematic review. A systematic search was performed using the PubMed (MEDLINE), EMBASE and Cochrane Library databases. All the studies dealing with the application of stem cells as a treatment for meniscal tears were pooled, data were extracted and analyzed. The studies were divided into two groups (pre-clinical and clinical), and then, discussed independently. RESULTS: A total of 18 studies were included. Thirteen were classified as "pre-clinical" and five as "clinical". The most commonly used cells were mesenchymal stem cells (MSC), derived from bone marrow (BMMSC), synovial tissue (SMSC), or adipose tissue (ADSC). Follow-ups ranged from 2 to 16 weeks for the pre-clinical studies and from 3 to 24 months for the clinical studies. All studies documented good results in terms of laboratory markers/scores, clinical and radiologic evaluation. CONCLUSIONS: Based on the currently available data, it is not possible to establish the best cell source or delivery method for the treatment of meniscal injuries. Bone Marrow derived stem cells delivered through injection represent the most studied approach, with the most promising results. However, the full impact of these therapies through their different sub-type of stem cells and implantation techniques still needs to be critically analyzed through larger randomized controlled trials with longer follow-up.

First Clinical Application of Polyurethane Meniscal Scaffolds with Mesenchymal Stem Cells and Assessment of Cartilage Quality with T2 Mapping at 12 Months.

BACKGROUND: Complex meniscal lesions often require meniscectomy with favorable results in the short term but a high risk of early osteoarthritis subsequently. Partial meniscectomy treated with meniscal substitutes may delay articular cartilage degeneration. PURPOSE: To evaluate the status of articular cartilage by T2 mapping after meniscal substitution with polyurethane scaffolds enriched with mesenchymal stem cells (MSC) and comparison with acellular scaffolds at 12 months. METHODS: Seventeen patients (18-50 years) with past meniscectomies were enrolled in 2 groups: (1) acellular polyurethane scaffold (APS) or (2) polyurethane scaffold enriched with MSC (MPS). Patients in the MPS group received filgrastim to stimulate MSC production, and CD90+ cells were obtained and cultured in the polyurethane scaffold. The scaffolds were implanted arthroscopically into partial meniscus defects. Concomitant injuries (articular cartilage lesions or cartilage lesions) were treated during the same procedure. Changes in the quality of articular cartilage were evaluated with T2 mapping in femur and tibia at 12 months. RESULTS: In tibial T2 mapping, values for the MPS group increased slightly at 9 months but returned to initial values at 12 months (P > 0.05). In the APS group, a clear decrease from 3 months to 12 months was observed (P > 0.05). This difference tended to be significantly lower in the APS group compared with the MPS group at the final time point (P = 0.18). In the femur, a slight increase in the MPS group (47.8 ± 3.4) compared with the APS group (45.3 ± 4.9) was observed (P > 0.05). CONCLUSION: Meniscal substitution with polyurethane scaffold maintains normal T2 mapping values in adjacent cartilage at 12 months. The addition of MSC did not show any advantage in the protection of articular cartilage over acellular scaffolds (P > 0.05).

Understanding the Implications of the Meniscal Ossicle: Patient Presentation, Treatment, and Outcomes.

The meniscal ossicle is observed in clinical practice, yet there currently is limited information on its potential clinical significance. The purpose of this study was to assess the clinical presentation, imaging findings, and clinical treatment and outcomes of a series of patients identified as having a meniscal ossicle. An institutional database was reviewed to identify knees with a meniscal ossicle. Clinical presentation, magnetic resonance imaging (MRI), treatment, and outcomes were analyzed. Radiographs were graded using Kellgren-Lawrence (KL) scores. MRIs were reviewed for the presence and location of meniscal ossicles and additional knee pathology. Knee arthroplasty rates were recorded with the remaining patients contacted to obtain final International Knee Documentation Committee (IKDC) and Tegner's scores. Failure was defined as conversion to arthroplasty or failing IKDC score (< 75.4). Forty-five meniscal ossicles in 45 patients (26 males and 19 females) with a mean age of 51 years (standard deviation [SD] = 19.0) were included. Pain was the most common presenting symptom (89%). Forty-two patients (93%) had an associated meniscus root tear on MRI. Eighteen percent of patients that did not have an ossicle on initial imaging subsequently developed an ossicle. Mean KL grades progressed significantly from baseline of 1.84 (SD = 1.0) to 2.55 (SD = 0.93 p < 0.01) on final follow-up. Thirty-nine percent of baseline radiographs showed KL grades of less than 2 compared with only 15% of follow-up radiographs (p = 0.04). Mean IKDC score obtained for patients ≤ 60 at an average follow-up of 3.1 years (SD = 3.2) was 65.2 (SD = 19.0). Eight out of 45 patients (18%) had progressed to total knee arthroplasty (TKA) by latest available follow-up. Sixty-two percent of patients met failure criteria at latest available follow-up. The meniscal ossicle is most commonly found in the posterior horn or root of the medial meniscus and is highly suggestive to be sequelae of a posterior root tear. Therefore, the presence of a meniscal ossicle should alert the orthopaedic surgeon to the high likelihood of the patient having a meniscus root tear. These patients have shown to have poor clinical outcomes and worsening arthritis.

Synovial mesenchymal stem cells promote the meniscus repair in a novel pig meniscus injury model.

Stem cell therapy has potential for the treatment of degenerative meniscus injuries; however, an optimal animal model has not been established. Basic and clinical research show that synovial mesenchymal stem cells (MSCs) promote meniscus repair. The purposes of this study were to create a novel meniscus injury model in microminipigs and to investigate the effectiveness of synovial MSCs on meniscus healing in this model. The posterior portion of the medial meniscus in microminipigs was punctuated 200 times with a 23G needle. Allogenic synovial MSC suspension was placed on the injury site for 10 min for transplantation. The meniscus was evaluated histologically and via sagittal magnetic resonance imaging (MRI), radial MRI reconstructed in three dimensional, and T2 mapping at 1 and 8 weeks. Proteoglycan content stained with safranin-o disappeared 1 week after treatment in both the MSC and control groups but increased at 8 weeks only in the MSC group. Histological scores at 8 weeks were significantly higher in the MSC group than in the control group (n = 6). At 8 weeks, the T2 values of the MSC group were significantly closer to those of a normal meniscus than were those of the control group. High signal intensity areas of the MRIs and positive areas stained with picrosirius red coincided with meniscal lesions. In conclusion, we created a novel meniscus injury model in microminipigs. Evaluation via histology, MRIs, and polarized microscopy showed that transplantation of synovial MSCs improved meniscus healing.