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The American Journal of Sports Medicine Nov 2023Unlike the adult meniscus, the fetal meniscus possesses robust healing capacity. The dense and stiff matrix of the adult meniscus provides a biophysical barrier for cell...
BACKGROUND
Unlike the adult meniscus, the fetal meniscus possesses robust healing capacity. The dense and stiff matrix of the adult meniscus provides a biophysical barrier for cell migration, which is not present in the fetal meniscus. Inspired by developmental characteristics, modifying the matrix of the adult meniscus into a fetal-like, loose and soft microenvironment holds opportunity to facilitate repair, especially in the avascular zone.
HYPOTHESIS
Modifying the dense and stiff matrix of the adult meniscus into a fetal-like, loose and soft microenvironment could enhance cell migration to the tear interface and subsequent robust healing capacity.
STUDY DESIGN
Controlled laboratory study.
METHODS
Fresh porcine menisci were treated with hyaluronidase or collagenase. The density and arrangement of collagen fibers were assessed. The degradation of proteoglycans and collagen was evaluated histologically. Cell migration within the meniscus or the infiltration of exogenous cells into the meniscus was examined. Dendritic silica nanoparticles with relatively large pores were used to encapsulate hyaluronidase for rapid release. Mesoporous silica nanoparticles with relatively small pores were used to encapsulate transforming growth factor-beta 3 (TGF-β3) for slow release. A total of 24 mature male rabbits were included. A longitudinal vertical tear (0.5 cm in length) was prepared in the avascular zone of the medial meniscus. The tear was repaired with suture, repaired with suture in addition to blank silica nanoparticles, or repaired with suture in addition to silica nanoparticles releasing hyaluronidase and TGF-β3. Animals were sacrificed at 12 months postoperatively. Meniscal repair was evaluated macroscopically and histologically.
RESULTS
The gaps between collagen bundles increased after hyaluronidase treatment, while collagenase treatment resulted in collagen disruption. Proteoglycans degraded after hyaluronidase treatment in a dose-dependent manner, but collagen integrity was maintained. Hyaluronidase treatment enhanced the migration and infiltration of cells within meniscal tissue. Last, the application of fibrin gel and the delivery system of silica nanoparticles encapsulating hyaluronidase and TGF-β3 enhanced meniscal repair responses in an orthotopic longitudinal vertical tear model.
CONCLUSION
The gradient release of hyaluronidase and TGF-β3 removed biophysical barriers for cell migration, creating a fetal-like, loose and soft microenvironment, and enhanced the fibrochondrogenic phenotype of reparative cells, facilitating the synthesis of matrix and tissue integration.
CLINICAL RELEVANCE
Modifying the adult matrix into a fetal-like, loose and soft microenvironment via the local gradient release of hyaluronidase and TGF-β3 enhanced the healing capacity of the meniscus.
Topics: Animals; Male; Rabbits; Transforming Growth Factor beta3; Hyaluronoglucosaminidase; Fibrocartilage; Menisci, Tibial; Rupture; Collagen; Proteoglycans; Collagenases; Silicon Dioxide
PubMed: 37743771
DOI: 10.1177/03635465231194028 -
European Journal of Radiology Aug 2016Meniscus allograft transplantation has been performed over the past 25 years to relieve knee pain and improve knee function in patients with an irreparable meniscus... (Review)
Review
Meniscus allograft transplantation has been performed over the past 25 years to relieve knee pain and improve knee function in patients with an irreparable meniscus injury. The efficacy and safety of meniscus allograft transplantation have been established in numerous experimental and clinical researches. However, there is a lack of reviews to aid radiologists who are routinely interpreting images and evaluating the outcome of the procedures, and also meniscus allograft transplantation is not widely performed in most hospitals. This review focuses on the indications of the procedure, the different surgical techniques used for meniscus allograft transplantation according to the involvement of the lateral and medial meniscus, and the associated procedures. The postoperative radiological findings and surgical complications of the meniscus allograft transplantation are also described in detail.
Topics: Allografts; Humans; Knee Joint; Magnetic Resonance Imaging; Menisci, Tibial; Postoperative Care; Postoperative Complications; Plastic Surgery Procedures
PubMed: 27423673
DOI: 10.1016/j.ejrad.2016.05.006 -
Journal of Pediatric Orthopedics Oct 2021Medial discoid meniscus (MDM) is an exceedingly rare anatomic abnormality that presents similarly to other meniscal pathologies. Symptomatic MDM is typically managed...
BACKGROUND
Medial discoid meniscus (MDM) is an exceedingly rare anatomic abnormality that presents similarly to other meniscal pathologies. Symptomatic MDM is typically managed arthroscopically with mixed short-term and long-term outcomes, although the existing knowledge about MDM is limited. The purpose of this study was to describe the presentation and surgical treatment of MDM in pediatric and adolescent patients.
METHODS
Medical records of 12 knees with MDM in 8 pediatric and adolescent patients treated between 1991 and 2016 were reviewed retrospectively for patient characteristics, clinical manifestations, radiographic findings, operative techniques, and surgical outcomes.
RESULTS
Of the 446 knees diagnosed arthroscopically with discoid menisci, lateral discoid meniscus was noted in 434 knees (97.3%) and MDM was present in 12 knees (2.7%). The MDM series included 8 patients of mean age 13.8 years (range: 7.8 to 19.8), of which 5 were males (63%), and 4 (50%) had bilateral involvement. Of the 11 knees with available clinical records, all cases presented symptomatically (pain, mechanical symptoms); 10 (91%) had concurrent physical exam findings. On intraoperative examination, discoid morphologies were described as complete in 4/8 knees (50%) or incomplete in 4/8 (50%), with associated instability in 6/12 (50%). Meniscal tears were reported in 9 cases (75%)-primarily, horizontal cleavage tears. Saucerization was performed in 11 knees (92%), with medial meniscal repair in 7 (58%), when indicated. Retear of the medial meniscus occurred in 4/11 knees (36%) at a mean of 25.8 months postoperation; 2 knees required revisions. One knee developed arthrofibrosis and underwent arthroscopic lysis of adhesions.
CONCLUSIONS
MDM is a rare diagnosis, representing 3% of all discoid menisci, with a nonspecific clinical manifestation. Operative management of symptomatic MDM typically involves saucerization and meniscal repair, when indicated, for concurrent tears. Symptom resolution is common short-term, but long-term outcomes include recurrent meniscal tears. Subsequent observational studies are important to evaluate long-term outcomes, such as arthritic changes, with the advancement of arthroscopic techniques for meniscal preservation.
LEVEL OF EVIDENCE
Level IV-retrospective case series.
Topics: Adolescent; Arthroscopy; Child; Female; Humans; Knee Joint; Male; Menisci, Tibial; Retrospective Studies; Treatment Outcome; Young Adult
PubMed: 34369475
DOI: 10.1097/BPO.0000000000001906 -
Journal of Ultrasound in Medicine :... Apr 2020Medial knee pain is commonplace in clinical practice and can be related to several pathologic conditions: ie, medial plica syndrome, saphenous nerve entrapment, pes... (Review)
Review
Medial knee pain is commonplace in clinical practice and can be related to several pathologic conditions: ie, medial plica syndrome, saphenous nerve entrapment, pes anserine syndrome, medial collateral ligament injury, and medial meniscus disorders. Ultrasound (US) imaging represents a valuable first-line diagnostic approach to adequately visualize the superficial structures in the medial compartment of the knee to easily plan for prompt treatment. Currently, the management of chronic degenerative diseases involving the menisci, and causing their extrusion, consists of surgery (arthroscopic partial meniscectomy). This procedure often allows only a partial resolution of pain and functional impairment. In the pertinent literature, US-guided interventions for the medial meniscus are proposed, mainly to decrease pain and inflammation or to induce regeneration. Likewise, this Technical Innovation describes in detail the US findings of medial extrusive meniscopathy and also illustrates a novel US-guided technique to treat the bursa of the medial collateral ligament, the extruded fragment of the medial meniscus, and the synovial parameniscal recesses simultaneously.
Topics: Clinical Protocols; Humans; Joint Diseases; Menisci, Tibial; Tibial Meniscus Injuries; Ultrasonography, Interventional
PubMed: 31617613
DOI: 10.1002/jum.15142 -
The Journal of Knee Surgery Mar 2020RAMP lesion, defined as peripheral detachment lesion of posterior horn of medial meniscus, has been shown to accompany anterior cruciate ligament (ACL) ruptures and is...
RAMP lesion, defined as peripheral detachment lesion of posterior horn of medial meniscus, has been shown to accompany anterior cruciate ligament (ACL) ruptures and is thought to play an important role in the knee joint stability. In this study, we aimed to present results of postoperative knee function scores and patient satisfaction after surgical repair of RAMP lesion. We included 15 patients who had undergone knee arthroscopy due to RAMP lesion in 2017. We recorded demographic data, diagnosis, pre- and postoperative International Knee Documentation Committee and Tegner-Lysholm scores of all patients. In this study, we included 15 patients: the number of male and female patients was eight and seven, respectively. The mean age of patients was 26.8 (18-35). Associated injuries included ACL rupture in 12 patients, additional medial meniscus lesion in 3 patients, lateral meniscus lesion in 3 patients, and superomedial patellar plicae syndrome in 2 patients. All patients had the same postoperative rehabilitation protocol. Mean preoperative Tegner-Lysholm knee score was 64.4 (53-75), while it was 82.5 (75-89) postoperatively, and mean preoperative and postoperative Visual Analogue Scale score at last postoperative follow-up were 5.26 (2-8) and 1.06 (0-2), respectively. All differences were found to be statistically significant. Meniscal RAMP lesions are commonly associated with ACL ruptures. RAMP repair significantly increases postoperative knee function scores and patient satisfaction following ACL reconstruction.
Topics: Adolescent; Adult; Anterior Cruciate Ligament Injuries; Arthroscopy; Female; Humans; Lysholm Knee Score; Male; Menisci, Tibial; Patient Satisfaction; Recovery of Function; Tibial Meniscus Injuries; Young Adult
PubMed: 30849785
DOI: 10.1055/s-0039-1677887 -
Arthroscopy : the Journal of... Oct 2023Medial meniscus posterior root tears (MMPRTs) occur frequently in middle-aged and older individuals. Female sex, increased body mass index, lower sports activity level,...
Medial meniscus posterior root tears (MMPRTs) occur frequently in middle-aged and older individuals. Female sex, increased body mass index, lower sports activity level, chondral lesions of the far posterior femoral condyles, anterior cruciate ligament degeneration, greater varus mechanical axis angle, steeper posterior slope of the medial tibial plateau, shallow concave shape of the medial tibial plateau, narrower intercondylar distance and notch width, bony spur formation, and medial meniscus posterior root impingement have been reported as significant risk factors for MMPRT development. Orthopaedic surgeons should recognize that the anatomic morphologies of the femur and tibia and the femorotibial interactions can affect the development of MMPRTs by increasing pathologic mechanical stresses on the medial meniscus posterior root.
Topics: Middle Aged; Female; Humans; Aged; Tibia; Menisci, Tibial; Lower Extremity; Femur; Lacerations
PubMed: 37716790
DOI: 10.1016/j.arthro.2023.03.013 -
Der Orthopade Dec 2021Meniscus root tears are radial tears in the region of the posterior insertion zones. Medial root injuries usually occur in individuals > 50 years of age without...
Meniscus root tears are radial tears in the region of the posterior insertion zones. Medial root injuries usually occur in individuals > 50 years of age without adequate trauma and are associated with obesity and varus deformities. The root lesion leads to a loss of ring tension, which results in extrusion of the meniscus and a strong increase in joint pressure that is biomechanically equivalent to a complete meniscectomy. When indicating arthroscopic transosseous refixation of the medial root lesion, factors such as accompanying cartilage damage, osteoarthritis, obesity and varus deformity must be taken into account. Injuries to the root of the lateral meniscus are mostly observed in younger patients in combination with a rupture of the anterior cruciate ligament. Arthroscopic transosseous refixation in combination with cruciate ligament surgery is therefore also recommended for type I and type II lesions. In summary, both the medial and the lateral root lesions of the menisci are injuries with high biomechanical relevance.
Topics: Anterior Cruciate Ligament Injuries; Arthroscopy; Humans; Knee Injuries; Menisci, Tibial; Meniscus; Tibial Meniscus Injuries
PubMed: 34767042
DOI: 10.1007/s00132-021-04192-8 -
Arthroscopy : the Journal of... Dec 2021Meniscus tears seen at the time of anterior cruciate ligament reconstruction are usually asymptomatic, and treatment varies greatly between surgeons, with meniscus...
Meniscus tears seen at the time of anterior cruciate ligament reconstruction are usually asymptomatic, and treatment varies greatly between surgeons, with meniscus repair being used for tears that could be left in situ. Recent outcome studies of most types of lateral meniscus tears show that leaving the tears in situ can give equal or superior results. Meniscus repair being performed for degenerative medial meniscus tears does not give better results than removing the tears. As an alternative to repair, trephination through the meniscus into the peripheral capsule can create many bloody channels to promote healing. Long-term follow-up of meniscus treatment with anterior cruciate ligament reconstruction can help us understand outcomes and prevent us from overtreating tears.
Topics: Anterior Cruciate Ligament Injuries; Anterior Cruciate Ligament Reconstruction; Humans; Knee Injuries; Menisci, Tibial; Tibial Meniscus Injuries
PubMed: 34863385
DOI: 10.1016/j.arthro.2021.06.016 -
Academic Radiology Apr 2022Meniscal ramp lesions are a special type of injury that affects the periphery of the posterior horn of the medial meniscus (PHMM) and/or its meniscocapsular attachments.... (Review)
Review
Meniscal ramp lesions are a special type of injury that affects the periphery of the posterior horn of the medial meniscus (PHMM) and/or its meniscocapsular attachments. They are strongly associated with acute and chronic anterior cruciate ligament (ACL) tears. These lesions have gained much prominence in recent years, due to a significant increase in their diagnosis and their important biomechanical involvement in the knee. It is known that their presence in ACL-deficient knees is related to instability and if they are not repaired during ACL reconstruction, they can ultimately cause the failure of the graft. Since this type of injury is often underdiagnosed due to its localization at the "blind" point of arthroscopic vision, it is crucial to make an accurate preoperative diagnosis of them with MRI. The objective of this article is to review the recent literature regarding meniscal ramp lesions and to summarize the anatomical, biomechanical and fundamentally diagnostic aspects, emphasizing the radiological findings described until now.
Topics: Anterior Cruciate Ligament Injuries; Anterior Cruciate Ligament Reconstruction; Humans; Knee Joint; Menisci, Tibial; Radiologists
PubMed: 33663972
DOI: 10.1016/j.acra.2021.02.005 -
Journal of Orthopaedic Research :... Jun 2018The dog has been used extensively as an experimental model to study meniscal treatments such as meniscectomy, meniscal repair, transplantation, and regeneration....
The dog has been used extensively as an experimental model to study meniscal treatments such as meniscectomy, meniscal repair, transplantation, and regeneration. However, there is very little information on meniscal kinematics in the dog. This study used MR imaging to quantify in vitro meniscal kinematics in loaded dog knees in four distinct poses: extension, flexion, internal, and external rotation. A new method was used to track the meniscal poses along the convex and posteriorly tilted tibial plateau. Meniscal displacements were large, displacing 13.5 and 13.7 mm posteriorly on average for the lateral and medial menisci during flexion (p = 0.90). The medial anterior horn and lateral posterior horns were the most mobile structures, showing average translations of 15.9 and 15.1 mm, respectively. Canine menisci are highly mobile and exhibit movements that correlate closely with the relative tibiofemoral positions. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1710-1716, 2018.
Topics: Animals; Biomechanical Phenomena; Dogs; Magnetic Resonance Imaging; Menisci, Tibial; Movement
PubMed: 29106743
DOI: 10.1002/jor.23800