Neovascularization in Meniscus and Tendon Pathology as a Potential Mechanism in Regenerative Therapies: Special Reference to Platelet-Rich Plasma Treatment

Neovascularization is a complex, multistep process that includes the activation of endothelial cells, degradation of the basement membrane surrounding the blood vessel, formation of tip cells, the sprouting, migration and proliferation of endothelial cells into the interstitial space, and then the generation of space in the matrix to allow for the formation of a new, proper lumen of a newly formed blood vessel. Abundant neovascularization can be found in tendinous tissue obtained from asymptomatic athletes or the meniscus early after the injury. The concept of neovascularization in musculoskeletal system disorders seems to be mainly associated with pain and poor clinical outcomes. On the one hand, this phenomenon allows for tissue regeneration, but on the other, it is present during the degeneration process in connective tissue. Establishing the current concept on neovascularization is also needed. A narrative review of the current literature was conducted using databases including Embase, PubMed and Cochrane. This review aims to investigate the exact role of the neovascularization process in tendon and meniscus lesions and its role as a potential target in clinics, specifically in platelet-rich plasma (PRP) therapy. The stabilization of the neovessels required to achieve the healed tissue, together with the standardization of the PRP injections, can offer an alternative future therapeutic approach for the treatment of tendinopathy and meniscal injuries.

Varus and Steep Medial Posterior Tibial Slope Are Risk Factors for Degenerative Medial Meniscus Lesions

Purpose: Degenerative medial meniscus lesions(DMMLs) is different from other meniscus injuries, which have a high incidence and easy to miss diagnosis in the middle-aged and elderly. The present study was designed to identify the risk factors for DMMLs among an Asian sample.Methods: The experimental group included 121 patients（ones partly confirmed during arthroscopic surgery) with DMMLs and the control group included 51 patients with no pathological changes identified by using 3.0-T magnetic resonance imaging (MRI) from January 2017 to January 2021 were analyzed retrospectively. By full-length anteroposterior radiographs of lower limbs in weight-bearing position of the two groups, the Hip-Knee-Ankle (HKA) angle in the coronal plane and the Medial Posterior Tibial Slope(MPTS) in the sagittal plane were measured by the MRI T1 sequence of the knee. The potential risk factors of DMMLs were analyzed by multivariate logistic regression. The independent variables included gender, age, body mass index (BMI), occupational kneeling, Kellgren-Lawrence (K-L) grade, HKA, and MPTS.Results: T-test analysis between the Experimental Group and the Control Group showed statistically significant differences in age (t=10.718, p<0.001), BMI (t=7.300, p<0.001), HKA (t=8.677, p<0.001), and MPTS (t=5.025, p<0.001). Chi-square test analysis between the two groups showed no statistically significant differences in gender (t=0.183, p=0.669) and occupational kneeling (t=0.339, p=0.560). Non-parametric analysis showed statistically significant differences in K-L (z=5.857, p<0.001) between the two groups. Logistic regression analysis showed that age, BMI, HKA, and MPTS were risk factors for DMMLs among the above-mentioned variables with statistically significant differences.Conclusions: varus, steep MPTS, advancing age and obesity were risk factors for DMMLs.

Evaluation of associated meniscal and chondral injuries in patients undergoing arthroscopic anterior cruciate ligament reconstruction

Objectives: Anterior cruciate ligament (ACL) injury of the knee is commonly associated with meniscal and chondral lesions. This study was performed to assess the relative risk factors as well as the extent of the meniscal and chondral pathology at the time of arthroscopic ACL reconstruction. Materials and Methods: In this prospective study, patients undergoing ACL reconstruction were enrolled. Association of meniscal and chondral lesions was analyzed with age, sex, body mass index (BMI), mechanism of injury (sports-related or not), time gap between injury and surgery (<3 month and >3 months), and instability episodes. Logistic regression and Pearson Chi-square test were applied for evaluating the association. Results: A total of 55 patients (mean age 30 years [19–50 years]; 45 male:10 female) underwent arthroscopic ACL reconstruction, out of which 20 (36.3%) had isolated lateral meniscus tear, 14 (25.4%) had isolated medial meniscus tear, and 3 (5.4%) had both lateral and medial meniscus tear. BMI (P = 0.031) and instability episodes (P = 0.033) were predictor for meniscal lesions. Male sex was associated with significantly higher medial (P = 0.049) and lateral meniscal (P = 0.008) lesions. The older age group (>30 years) was associated with medial meniscus lesions (P = 0.047), while the younger age group (<30 years) had significantly higher lateral meniscal lesions (P = 0.008). Chronic ACL injuries (>3 months) had a significantly higher risk of medial meniscus lesions (P = 0.006). Age (>30 years) (P = 0.002) and obesity (BMI >30 kg/m2) (P = 0.043) were predictors of chondral lesions. Conclusion: Significant association is observed between age (>30 years), male gender, obesity, and chronicity with medial meniscal injuries in patients with an ACL injury, while younger patients (<30 years) and patient operated within 3 months had a higher incidence of lateral meniscus lesions. Age and BMI (>30 kg/m2) were predictors of chondral lesions in ACL injury.

Single isotropic 3D fast spin echo sequence compared with conventional 2D sequences for detecting meniscal and cruciate ligament tears in the knee

Background This work was conducted to assess the diagnostic efficiency of isotropic three-dimensional VISTA-fast spin echo versus standard two-dimensional fast spin echo at 1.5 T MRI, in the assessment of internal knee derangement in symptomatic patients, aiming to obtain similar diagnostic accuracy in a shorter time span, with reduction of partial volume artifacts by thin continuous sections. Results This was a non-randomized control study including 39 patients (32 male and 7 females, mean age 37 years old). A correlative study was done utilizing MRI standard 2D FSE (protocol A) versus 3D-VISTA-FSE (protocol B) for medial meniscus (MM) and lateral meniscus (LM), as well as anterior cruciate ligament ACL lesions, comparing the MRI results with the findings of arthroscopy as the gold standard. Both protocols depicted medial meniscus lesions with accuracy, specificity, and sensitivity (97.44%, 96.30%, and 100% respectively), lateral meniscus lesions with accuracy, specificity, and sensitivity (97.44%, 100%, and 50% respectively), and ACL lesions with accuracy, specificity, and sensitivity (100%, 100%, and 100% respectively), while there were no PCL lesions depicted through the study population. Comparing the time factor between both protocols revealed protocol A to consume 13.7 min, while protocol B consumed 6.6 min. Conclusion Three-dimensional isotropic VISTA-FSE sequence, although having similar accuracy in diagnosing cruciate and meniscal lesions as the standard sequences, facilitates thin-section data acquisition and multi-planar image reformation in standard and non-standard planes, without intersection gaps that are crucial for the detection and dissection of compound structures; also, it allows a shorter time span, which is more advantageous for patients, particularly the traumatized and emergency patients.

The menisci and articular cartilage: a life-long fascination

The menisci and articular cartilage of the knee have a close embryological, anatomical and functional relationship, which explains why often a pathology of one also affects the other. Traumatic meniscus tears should be repaired, when possible, to protect the articular cartilage. Traumatic articular cartilage lesions can be treated with success using biological treatment options such as microfracture or microdrilling, autologous chondrocyte transplantation (ACT), or osteochondral transplantation (OCT) depending on the depth and area of the lesion. Degenerative cartilage and meniscus lesions often occur together, and osteoarthritis is already present or impending. Most degenerative meniscus lesions should be treated first conservatively and, after failed conservative treatment, should undergo arthroscopic partial meniscus resection. Degenerative cartilage lesions should also be treated conservatively initially and then surgically; thereby treating the cartilage defect itself and also maintaining the axis of the leg if necessary. Tears of the meniscus roots are devastating injuries to the knee and should be repaired e.g. by transtibial re-fixation. The clinical role of ‘ramp’ lesions of the meniscus is still under investigation. Cite this article: EFORT Open Rev 2020;5:652-662. DOI: 10.1302/2058-5241.5.200016

Determination of the classification-based tactics for treating meniscus lesions in children

New approaches to the treatment of meniscus lesions is currently a hot topic in traumatology and orthopedics. Meniscus resection and suture issues are widely discussed and studied in modern literature. Current trends in the care of meniscus pathologies are aimed to restore the structure of the damaged segment by stitching it using various techniques. A classification scale plays an important role in the treatment of any disease because it allows to uniformly describe the main criteria of pathology and to define a treatment tactics. The given review describes modern classifications of meniscus lesions with their advantages and disadvantages.

Quantitative Evaluation of Meniscal Healing Process of Degenerative Meniscus Lesions Treated with Hyaluronic Acid: A Clinical and MRI Study

Purpose: We aimed to evaluate clinical efficacy and healing effects of conservative management of degenerative meniscus lesions (DMLs) with a hyaluronic acid (HA) hydrogel. Methods: Patients were subjected to two HA injections two weeks apart. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Patient’s Global Assessment (PtGA) and Clinical Observer Global Assessment (CoGA) of the disease were assessed at baseline, 30, and 60 days after treatment. Short Form (36) Health Survey (SF-36) was assessed at baseline and 60 days after treatment. One year after treatment, patients were called to know whether any of them had undergone arthroscopic partial meniscectomy (APM). All patients underwent magnetic resonance imaging using a 1.5-T Magnetic Resonance Imaging (MRI) scanner (Siemens Aera), which included a T2 mapping pulse sequence with multiple echoes at baseline and 60 days after treatment. Results: 40 patients were enrolled. WOMAC score, physical function subscale, PtGA and CoGA, and SF-36 showed a statistically significant difference between baseline and follow-up. One year after treatment, only one patient had undergone APM. A decrease in the T2 measurement was detected in the posterior horn medial meniscus in 39% of cases in both the red and red–white zone, and in 60% of cases in the white zone; in the posterior horn lateral meniscus in 55% of cases in both the red and white zones, and in 65% of cases in the red–white zone. Only for the latter, there was a statistically significant difference between baseline and posttreatment T2 measurements. Conclusion: This study supports the use of HA in the conservative management of DML as it is clinically effective and enhances meniscus healing as demonstrated by T2 measurements. Moreover, it reduces the need for APM at 1-year follow-up.

Arthroscopic meniscectomy versus non-surgical or sham treatment in patients with MRI confirmed degenerative meniscus lesions: a protocol for an individual participant data meta-analysis

IntroductionArthroscopic partial meniscectomy (APM) after degenerative meniscus tears is one of the most frequently performed surgeries in orthopaedics. Although several randomised controlled trials (RCTs) have been published that showed no clear benefit compared with sham treatment or non-surgical treatment, the incidence of APM remains high. The common perception by most orthopaedic surgeons is that there are subgroups of patients thatdoneed APM to improve, and they argue that each study sample of the existing trials is not representative for the day-to-day patients in the clinic. Therefore, the objective of this individual participant data meta-analysis (IPDMA) is to assess whether there are subgroups of patients with degenerative meniscus lesions who benefit from APM in comparison with non-surgical or sham treatment.Methods and analysisAn existing systematic review will be updated to identify all RCTs worldwide that evaluated APM compared with sham treatment or non-surgical treatment in patients with knee symptoms and degenerative meniscus tears. Time and effort will be spent in contacting principal investigators of the original trials and encourage them to collaborate in this project by sharing their trial data. All individual participant data will be validated for missing data, internal data consistency, randomisation integrity and censoring patterns. After validation, all datasets will be combined and analysed using a one-staged and two-staged approach. The RCTs’ characteristics will be used for the assessment of clinical homogeneity and generalisability of the findings. The most important outcome will be the difference between APM and control groups in knee pain, function and quality of life 2 years after the intervention. Other outcomes of interest will include the difference in adverse events and mental health.Ethics and disseminationAll trial data will be anonymised before it is shared with the authors. The data will be encrypted and stored on a secure server located in the Netherlands. No major ethical concerns remain. This IPDMA will provide the evidence base to update and tailor diagnostic and treatment protocols as well as (international) guidelines for patients for whom orthopaedic surgeons consider APM. The results will be submitted for publication in a peer-reviewed journal.PROSPERO registration numberCRD42017067240.