Vertical Tears Research Articles

All-Inside Repair of a Radial Lateral Meniscal Root Tear With an Anterior Cruciate Ligament Injury

Background: Root tears are functionally compromising injuries that require an anatomic repair for functional restoration of native joint mechanics. Posterior root tears of the lateral meniscus are commonly associated with anterior cruciate ligament (ACL) ruptures as lateral root tears contribute to anterolateral rotational instability. Two-tunnel transtibial root repair allows for root repair with superior pullout strength and can be combined with ACL reconstruction to treat this injury pattern. Indications: Two-tunnel transtibial root repair is indicated in active patients with meniscal root tears that have low-grade chondromalacia (grade II or less). It is contraindicated in patients with advanced degenerative changes (grade III-IV), severe mal-alignment, and extrusion related to advanced degenerative changes; those who cannot complete postoperative rehabilitation; and patients with significant medical comorbidities. Technique Description: After repairing a vertical horn tear of the posterior medial meniscus, a vertical tear of the posterior root of the lateral meniscus was observed. Following preparation of the anatomic footprint, 2 transtibial tunnels were drilled and sutures were passed and secured using a surgical button over the anterior tibial cortex. Horizontal repair of the tear was then performed using 2 all-inside devices. Subsequently, an ACL reconstruction was performed. Results: At 11 months postoperative, the patient has continued to progress as expected. She was able to ambulate without pain, had a symmetric and balanced gait, and was able to return to running. Discussion/Conclusion: Lateral meniscal root repairs using 2 transtibial tunnels and concomitant ACL reconstruction have yielded good and reliable clinical outcomes with low failure rates and low rates of revision surgery.

The natural long-term course of unrepaired ramp lesion: a retrospective analysis of 28 patients followed for at least 20 years

Objectives:Ramp lesion is a specific type of injury, located in the posterior horn of the medial meniscus. The purpose of the study was to evaluate the complications for meniscal ramp lesions left in situ during ACL reconstruction, after more than 20 months of follow up.Methods:All patients who underwent arthroscopic ACLR between January 1998 and December 2000 were evaluated retrospectively. Surgery was performed by the same surgeon. In case of a stable vertical tear, i.e. without instability, the lesion was left in situ, without suture or debridement. The following parameters were examined: demographics; history and clinical findings including time between injury and surgery, side-to-side laxity, pivot shift; knee function and activity by Lysholm score, subjective IKDC, KOOS and Tegner activity scale; and progression to bucket handle. We established two groups: the bucket handle group versus the no bucket handle group.Results:A total of 716 patients underwent a primary ACLR during this period. The overall incidence of ramp lesions in the study population was 5.4% (39 ramp lesions in 716 patients). Mean follow-up time was 262.1 (± 10.5) months. Bucket handle tear of the medial meniscus occurs in 21.4% of our population, with an average lead time of 99 (± 50) months, and a concentration of injuries between 96 and 156 months. The postoperative scores significantly improved for the entire population at more than 20 years of follow-up (p <0.0001), except for the Tegner score (p = 0.3424). Functional scores and side-to-side laxity were the same for the two groups. No risk factors were identified.Conclusion:There is a high incidence of bucket-handle injury after ACL surgery with a residual ramp lesion (21.4%). This high rate is only found in series with a long follow-up, since these lesions appear between 8 and 12 years after the first surgery.

Évolution naturelle à long terme d’une lésion de la rampe non réparée : analyse rétrospective de 28 patients suivis pendant au moins 20 ans

Ramp lesion is a specific type of injury, located in the posterior horn of the medial meniscus. The purpose of the study was to evaluate the complications for meniscal ramp lesions left in situ during ACL reconstruction, after more than 20 of follow-up. All patients who underwent arthroscopic ACLRs between January 1998 and December 2000 were evaluated retrospectively. Surgery was performed by the same surgeon. In case of a stable vertical tear, i.e. without instability, lesion was left in situ, without suture or debridement. The following parameters were studied: demographics; history and clinical findings including time from injury to surgery, side-to-side laxity, pivot shift; knee and activity function by Lysholm score, subjective IKDC, KOOS and Tegner activity scale; and evolution to bucket handle. We defined two groups: bucket handle group versus no bucket handle group. A total of 716 patients underwent a primary ACLR during this period. The overall incidence of ramp lesions in the study population was 5.4% (39 ramp lesions in 716 patients). Mean follow-up time was 262.1 (± 10.5) months. The occurrence of medial meniscus bucket handle represented 21.4% of our population, with an average delay of 99 (± 50) months, and a concentration of this injury between 96 and 156 months. The postoperative scores were significantly improved for the whole population at more than 20 years of follow-up ( P < 0.0001), except for the Tegner score ( P = 0.3424). Functional scores and side-to-side laxity was the same for the two groups. No risk factors were identified. There is a high incidence of bucket-handle injury after ACL surgery with a ramp lesion left in place (21.4%). This high rate is only found in series with a long follow-up, since these lesions appear between 8 and 12 years after the first surgery.

Use of an Accessory Anteromedial Portal to Facilitate Repair of Mid-Body Radial Tears of the Lateral Meniscus in Children and Adolescents

Meniscal tears in adolescent patients are commonly treated with repair to preserve meniscal tissue and prevent future degenerative changes. Historically, meniscal tears best suited for repair are acute vertical tears in patients aged <40 years with a normal mechanical axis, >1 cm and <4 cm in size, within the red–red zone, and concurrent with anterior cruciate ligament reconstruction. However, with continued advancements in technology and the development of new techniques, the possibilities and indications for meniscal repair have broadened. This paper presents the use of an accessory medial portal to facilitate the repair of radial tears of the mid-body of the lateral meniscus. Previous techniques described include all-inside, outside-in, and inside-out repairs, but these techniques can be challenging to achieve optimal simultaneous meniscus reduction, visualization, and suture trajectory. In this Technical Note, we describe the use of an inside-out technique, with emphasis on an accessory anteromedial portal to improve visualization and suture trajectory.

Six-Month Outcomes of Clinically Relevant Meniscal Injury in a Large-Animal Model.

Background:The corrective procedures for meniscal injury are dependent on tear type, severity, and location. Vertical longitudinal tears are common in young and active individuals, but their natural progression and impact on osteoarthritis (OA) development are not known. Root tears are challenging and they often indicate poor outcomes, although the timing and mechanisms of initiation of joint dysfunction are poorly understood, particularly in large-animal and human models.Purpose/Hypothesis:In this study, vertical longitudinal and root tears were made in a large-animal model to determine the progression of joint-wide dysfunction. We hypothesized that OA onset and progression would depend on the extent of injury-based load disruption in the tissue, such that root tears would cause earlier and more severe changes to the joint.Study Design:Controlled laboratory study.Methods:Sham surgeries and procedures to create either vertical longitudinal or root tears were performed in juvenile Yucatan mini pigs through randomized and bilateral arthroscopic procedures. Animals were sacrificed at 1, 3, or 6 months after injury and assessed at the joint and tissue level for evidence of OA. Functional measures of joint load transfer, cartilage indentation mechanics, and meniscal tensile properties were performed, as well as histological evaluation of the cartilage, meniscus, and synovium.Results:Outcomes suggested a progressive and sustained degeneration of the knee joint and meniscus after root tear, as evidenced by histological analysis of the cartilage and meniscus. This occurred in spite of spontaneous reattachment of the root, suggesting that this reattachment did not fully restore the function of the native attachment. In contrast, the vertical longitudinal tear did not cause significant changes to the joint, with only mild differences compared with sham surgery at the 6-month time point.Conclusion:Given that the root tear, which severs circumferential connectivity and load transfer, caused more intense OA compared with the circumferentially stable vertical longitudinal tear, our findings suggest that without timely and mechanically competent fixation, root tears may cause irreversible joint damage.Clinical Relevance:More generally, this new model can serve as a test bed for experimental surgical, scaffold-based, and small molecule–driven interventions after injury to prevent OA progression.

Second-Look Arthroscopic Evaluation of Healing Rates After Arthroscopic Repair of Meniscal Tears: A Systematic Review and Meta-analysis.

Background:Evaluation of meniscal healing status after repair is important, as it allows the surgeon to inform patients whether they can increase their activities or return to sports.Purpose:To identify the healing rates after arthroscopic repair of meniscal tears via second-look arthroscopic evaluation.Study Design:Systematic review; Level of evidence, 4.Methods:Searches of PubMed, Embase, Scopus, and the Cochrane databases were conducted to identify relevant studies published before June 1, 2020. Studies were eligible for this meta-analysis if they provided data regarding healing status of the meniscus at second-look arthroscopy. Random-effects meta-analyses were generated to provide pooled meniscal healing estimates. We further performed subgroup analysis to investigate the healing rates of the meniscus under different situations.Results:A total of 41 studies with 1908 individuals were included in the study. The pooled analysis showed the complete healing rate was 74% (95% confidence interval [CI], 67%-80%), the partial healing rate was 10% (95% CI, 6%-16%), and the failure rate was 12% (95% CI, 10%-15%) for arthroscopic repair of meniscal tears via second-look arthroscopic evaluation. Sensitivity analysis demonstrated that no individual study affected the overall healing rate by >1%. Subgroup analysis found higher meniscal healing rates in patients with the following characteristics: age <40 years, male, body mass index <26, red-red tear location, tear in posterior horn, vertical tear, outside-in technique, repair concomitant with anterior cruciate ligament reconstruction, weight-restricted rehabilitation, and time interval from meniscal repair to second-look arthroscopy >12 months.Conclusion:In this systematic review, the complete healing rate was 74%, the partial healing rate was 10%, and the failure rate was 12% for arthroscopic repair of meniscal tears via second-look arthroscopic evaluation.

All-Inside Double-Sided Suture Repair for Longitudinal Meniscal Tears

The current consensus in the literature is that the meniscus must be saved. Even though inside-out sutures are still considered as the gold standard, the need to alternate between intra- and extra-articular structures for every stitch makes it laborious. New generations of all-inside systems are now routinely used in operating rooms and enable easier, quicker, and safer techniques. However traditional all-inside repair with limited upper fixation does not provide uniform compression from top to down, essential precondition for satisfactory meniscal healing. This Technical Note describes a simple and accessible alternative technique that provides stable fixation and overall compression of vertical meniscal tears from top to down with standard all-inside instrumentation.

Surgical Outcomes after Bucket Handle Meniscus Repairs: analysis of a large contained cohort study

Objectives:Comprising approximately 10% of all mensiscus tears, bucket-handle meniscus tears are large longitudinal vertical meniscus tears that have an attached fragment flipped into the intercondylar notch. Meniscectomy would often result in significant meniscal loss and increased joint loading. Alternatively, meniscus repair attempts to restore the function of the meniscus and aims to preserve joint mechanics. The objective of this observational data-only study is to evaluate the long-term risk of subsequent ipsilateral knee surgery in patients who underwent a bucket handle meniscus repair and assess risk factors associated with subsequent knee surgical intervention.Methods:We performed an electronic health records search for all patients who underwent arthroscopic knee meniscal repairs from 2011 to 2018. Natural language processing was used to search for terms of interest in the long operative notes to determine if these surgeries were performed for bucket handle meniscus tears. These patients comprised our initial cohort. Study subjects were followed for at least one year and up to five years with censoring at death, membership disenrollment, or 12/31/2019. Baseline patient characteristics and outcomes (i.e., subsequent operative procedures, deep surgical site infections, and deep venous thrombosis) were evaluated via a database review. Descriptive statistics were employed.Results:The median follow-up time was 4.2 years (interquartile range [IQR] 2.7-5.0 years). A total of 1353 patients underwent meniscus repair surgery for a bucket-handle meniscus tear. The median age was 24 years (IQR 17-34). During the follow-up period, 492 subsequent ipsilateral procedures were performed in 272 (20.1%) patients. 59 (4.3%) patients underwent a subsequent repeat meniscus repair and 164 (12.1%) patients underwent a subsequent meniscectomy. The median time to first procedure was 41.1 months (IQR 23.3-60 months). Younger age and lower BMI were significant risk factors for having subsequent surgery (adjusted odds ratio [aOR] 1.04, 95% Confidence Interval [95%CI] 1.02-1.05, and aOR 1.60, 95%CI 1.09-2.35, respectively). Patients undergoing concomitant ACL reconstruction had a lower risk of undergoing subsequent surgery (aOR 0.66, 95%CI 0.50-0.88).Conclusions:This is the largest reported contained patient cohort study on outcomes after bucket-handle meniscus repair. 20% of patients underwent repeat surgery during the follow-up time period with 4.3% experiencing a subsequent repeat meniscus repair and 12% experiencing a subsequent meniscectomy. Risk factors for subsequent surgery include younger age and lower BMI. Concomitant ACL reconstruction at time of bucket-handle meniscus repair reduced the risk of subsequent reoperation.

Surgical meniscal lesions in stable knee: Topographic description in a prospective series of 1424 cases

BackgroundThe epidemiology of meniscal lesions in stable knee has been a focus of study, but exact topography is not clearly known. Tear patterns are thought to differ between pathologies and the difference between a traumatic and a degenerative pattern is not always easy to draw. In 2010, ISAKOS designed a questionnaire to standardize assessment. The main objective of present study was to detail the precise topography and type of surgical meniscal patterns (i.e., that were operated on) in stable knee. Secondary objectives were to assess the relationship of tear pattern and cartilage lesions in the tibiofemoral compartment, and to analyze age at onset. HypothesesThe study hypotheses were that tear pattern correlates with cartilage lesions, and that mean age differs according to tear pattern, with younger onset of vertical tears, in surgery@ patients. Patients & methodsData collection for this descriptive epidemiological study was prospective, on systematic ISAKOS questionnaire. 1424 isolated meniscal tears in stable knee, operated on between 2010 and 2017, were included: 253 lateral meniscus (LM), and 1171 medial meniscus (MM). Mean age at surgery was respectively 36 and 47 years. ResultsThe most frequent tear pattern was vertical (39% in LM, 38% in MM). The more frequent locations were posterior+midpart and midpart (22% each) in LM, and posterior in MM (56%). Tears were mainly peripheral (zone 1) in LM (46%), and zone 2 in MM (46%). Mean age in medial vertical tears was 43±14 years, significantly lower (p<0.001) than in other types. Meniscal tear pattern correlated significantly with medial tibiofemoral cartilage lesion (p<0.001). DiscussionThe present study described the precise topography of isolated meniscal tears in stable knee in a large sample, using the ISAKOS questionnaire. The study hypotheses were confirmed for the medial but not the lateral meniscus. Level of evidenceIII; well-conducted non-randomized prospective comparative study.

MRI evaluation of internal derangement in traumatic knee

The knee is one of the most commonly injured joint. Knee injury is the second most common problem in the musculoskeletal system for which patients consult their general physician. In acute situations, radiographs can be very useful to diagnose or rule out fractures. A second category of patients’ have sub-acute or even chronic symptoms that may be related to trauma, overuse, degeneration, etc. The study population includes all the patients presenting with history of and /or clinical findings suggestive of knee trauma and use MRI for evaluation. The MRI is done on the advice of the referring doctor and no patient is made to undergo MRI knee for the sole purpose of this study. Posterior horn of medial meniscus was observed to be the most commonly injured. Vertical tear of medial meniscus was identified as the most common type of injury.

Forearc Crustal Structure of Ecuador Revealed by Gravity and Aeromagnetic Anomalies and Their Geodynamic Implications

AbstractAlong the Western Cordillera of Ecuador, fault-bounded ophiolites derived from the Late Cretaceous Caribbean Large Igneous Province (CLIP) have provided key petrotectonic indicators that outline the nature and the mechanism of continental growth in this region. However, most of the forearc basement across Western Ecuador is buried under sediments impairing its crustal structure understanding. Here, we propose a first crustal model throughout the spectral analysis of gravity and aeromagnetic data, constrained by observations made both at the surface and at the subsurface. Three main geophysical domains, within the North Andean Sliver in Western Ecuador, have been defined based on spectral analysis and augmented by 2D forward models. An outer domain, characterized by magnetic anomalies associated with mafic rocks, coincides with evidence of a split intraoceanic arc system. An inner domain is governed by long-wavelength mid to deep crust-sourced gravity and magnetic anomalies possibly evidencing the root of a paleoisland arc and the residuum of a partial melting event with subsequent associated serpentinization, the latest possibly associated with an obduction process during the middle Eocene-Oligocene. In addition, our model supports the presence of a lithospheric vertical tear fault, herein the southern suture domain, inherited from an oblique arc-continent interaction. Our interpretation also brings new insights and constraints on the early geodynamic evolution of the Ecuadorian forearc and provides evidence on the structural style and preservation potential of the forearc basement, most likely the roots of a mature island arc built within an oceanic plateau.

Updates and Advances in the Management of Lateral Meniscal Radial Tears: A Critical Analysis Review.

Because of their increased mobility, lack of resistance to hoop stresses, and decreased blood supply, radial tears of the lateral meniscus are more troublesome to heal than vertical longitudinal tears. Given the success of meniscal root repairs, radial tears of the lateral meniscal body should be given strong consideration for repair because of a more reproducible ability to heal such lesions in young, active patients. Technique options that should be considered for the less common anterior radial tears of the lateral meniscus include outside-in repair, self-capturing suture-passing devices, and orthobiologic treatments to stimulate healing. Although a variety of suture techniques, including the double horizontal mattress and horizontal butterfly patterns, have demonstrated improvements in patient outcomes, evidence is still limited with regard to the ideal suture pattern for radial tears.

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Influence of Upper Mantle Anisotropy on Isotropic P‐Wave Tomography Images Obtained in the Eastern Mediterranean Region

AbstractSeismic body‐wave tomography studies typically assume an isotropic upper mantle, possibly mapping anisotropy into artificial isotropic velocity anomalies in the resulting images. The Eastern Mediterranean with its oceanic, continental, and extinct subduction systems, as well as dense station coverage, provides an ideal setting to explore this issue. To examine the influence of seismic anisotropy, our study deals with both synthetic and real data inversions in which realistic seismic anisotropy models derived from 3D mantle convection simulations and shear wave splitting measurements are taken as a priori constraints. Spatial large‐scale velocity perturbations are mostly consistent between models derived with and without considering anisotropy. Small differences in the magnitude (up to 2%) and shape of velocity perturbations occur, and some structures are less diffuse when including anisotropy. Additionally, good backazimuthal coverage of teleseismic events and a larger data set improve the resolution of our model with respect to previous tomography studies and allow us to better interpret first‐order isotropic velocity anomalies. Key features, such as the half‐arc subducting oceanic plate in the southern Aegean and a wide and deep tear in the slab beneath southwestern Turkey, are clearly visible in all models. Our final tomography images also provide evidence for a shallow horizontal tear in the northern Hellenides and a vertical tear between two parts of the Cyprian slab. In eastern Anatolia, slab‐related high‐velocity anomalies are absent due to the continental collision and break‐off.

Alternative All-Inside Technique of Repairing a Vertical Meniscus Tear

Lateral meniscus vertical tears are often seen with acute anterior cruciate ligament injuries. The inside-out technique of repairing the meniscal tear is currently the gold standard treatment. However, every technique has its own drawbacks. The inside-out technique has possible risk of infection and neurovascular complications. All-inside techniques are becoming increasingly popular. A novel all-inside technique and a variation of it for meniscus repair using an antegrade suture passer like a Knee Scorpion are described. These are cost effective using a 2-0 FiberWire for repair of vertical meniscal tears. This technique also provides a better control of reduction at tear site through tensioning the 2 suture limbs. It is cost effective, easy to use, and has less neurovascular complications as compared with the inside -out technique.

A short term functional outcome of bucket handle medial meniscus tears treated with arthroscopic repair: All-inside technique in a rural tertiary care hospital

Bucket-handle meniscal tears are defined as vertical longitudinal tears of the meniscus with displacement of the torn inner fragment toward the intercondylar notch region. It is most commonly encountered in medial meniscus. Management of bucket handle tears is important to preserve knee function & preserving the meniscus will limit future osteoarthrosis. A series of 20 cases of bucket handle medial meniscus tears were treated by Arthroscopic repair: All-inside technique and were followed up regularly till 6months and evaluated using Lysholm Knee Scoring Scale. Most patients had Excellent score at 6th month follow-up. Our study suggests Arthroscopic repair: All-inside technique is an effective management of medial meniscus bucket handle tears.

Structural Controls on Aftershock Distribution in Subduction Zones

The trench-parallel distribution of aftershocks generated after a major subduction-related earthquake does not conform to a fractal or normal distribution as expected but does appear to be spatially constrained by fractures on the subducting oceanic crust. Newly developed and very detailed 3D models of subducting plates (slabs) are combined with high-resolution topographic and bathymetric models of the crustal upper-plate and subducting lower-plate respectively to show how irregularities such as transform faults, spreading centers, fossil subduction zones and vertical tears form structural barriers to the spatial distribution of subduction zone aftershocks. When correctly constructed, slab models can now be used to better forecast the lateral (along-arc) extent of damaging aftershock swarms following large magnitude subduction-related earthquakes. Two earthquakes, (magnitude MW 7.8 in Vanuatu, 7th October 2009 (UTC) and magnitude MW 8.8 in southern Chile, 27th February 2010 (UTC)) were followed by hundreds of aftershocks, with many recording magnitudes over MW 6.5. Closer examination of these aftershocks and their spatial distribution indicate that they were unexpectedly confined to discrete sections of the subducting plate. It is revealed here that lithospheric-scale structures including fossil oceanic transform faults represent crustal and lithosphere-scale fractures in the crust that terminates the lateral spread of aftershocks. This contrasts with the predicted decrease in aftershock size and number with increasing distance from the epicenter referred to as the Omori (power law) distribution. This hypothesis addresses the paradigm that oceanic crust is a single, semi-continuous and uniform section of crust where the lateral distribution of earthquakes is described in terms of uniform rock mechanics. Additional research on the MW 9.0 earthquake in Japan (11th March 2011 (UTC)) and the MW 8.0 earthquake in the eastern Solomon Islands (6th February 2013 (UTC)) supports the aforementioned hypothesis. Using new techniques to help define the location of sub-plate boundaries, it is now possible to generate aftershock probability maps for some of the most seismically active subduction margins around the world.

The Kefalonia Transform Fault: A STEP fault in the making

Vertical edges along subducted slabs have been recognized in the majority of subduction zones. Surprisingly, slab edges evolved into Subduction-Transform-Edge-Propagator (STEP) faults in only a few regions; the conditions under which STEPs form are special. It is relevant to constrain the conditions that facilitate STEP fault initiation because they leave a clear geological footprint in the overriding plate, whereas vertical tears generally do not. We therefore study a candidate region for STEP fault initiation in the western Hellenic Subduction Zone.We investigate the structure and seismicity of the shallow western Hellenic Subduction Zone using a recent full-waveform inversion model which both captures details of crustal and upper-mantle structure, yielding constraints in the depth interval from 10 to 200 km where lithosphere-mantle interactions have tectonic expressions. The western end of the Hellenic Subduction Zone is fragmented near the Kefalonia Transform Fault. We identify a separate Epirus lithospheric fragment that is roughly vertical below the southern Albanides. We also identify a new and major contrast within the lithospheric mantle of the Ionian ocean basin, which aligns with a gradient in free-air anomalies.In the overriding plate, the Kefalonia Transform Fault zone accommodates right lateral strike-slip deformation. We interpret this fault zone as a proto-STEP fault that formed simultaneously with Pliocene fragmentation of the Epirus fragment.Comparing the recent evolution of the NW Hellenic slab edge with currently active STEPs indicates that along-trench variations in convergence velocity are a prerequisite for STEP fault initiation. Such velocity variations may result from subduction of continental crust along part of the trench. Resistance to sea ward tear propagation by a mechanically strong subducting plate may prevent variations in convergence velocity to occur, and thus STEP fault initiation. The amount of time over which a velocity contrast persists will also be relevant for STEP fault initiation. Mechanical coupling between upper- and lower-plate, and the deformability of the upper-plate appear to also play a role in the initiation of the STEP fault once a slab is fragmented.

Contact mechanics after mattress suture repair of medial meniscus vertical longitudinal tear: an in vitro study.

Most studies have concentrated on the changes in contact pressure and area on the tibiofemoral joint. This study compared the contact mechanics underneath the medial meniscus of a repaired vertical longitudinal tear with that of the intact or the torn ones. In this controlled laboratory study, a 1000 N compressive axial load was applied to eight fresh-frozen cadaveric knees at four flexion angles and four loading conditions using a custom testing apparatus attached to a material testing machine. Intact knees, knees with a medial meniscus vertical longitudinal tear, and knees after meniscal repair were tested. The peak contact pressure and area underneath the meniscus were measured using Fuji pressure-sensitive film. A medial meniscus vertical longitudinal tear significantly increased the contact pressure and decreased contact area underneath the meniscus compared with those at the intact meniscus under all tested biomechanical conditions, and repair of the tear can restore the contact pressure and area in most conditions. While the repaired group showed a significantly higher or similar contact pressure compared with the tear group at 90° neutral knee position and at 60°, 90° 5 N·m-external rotation and 134 N-anterior tibial translation, and 5 N·m-internal rotation at all flexion angles. The contact area corresponding to the aberrant result of the contact pressure in the repaired group was lower than in the intact meniscus group. The contact mechanics underneath the meniscus of the repaired medial meniscus vertical longitudinal tear were significantly improved compared with the corresponding tear conditions in most cases, while the contact pressure and area at some certain status after repair were not significantly different from those of the corresponding tear conditions.

Effect of platelet-rich plasma and platelet-rich fibrin matrix on healing of vertical meniscal tears in a rabbit model.

This study aimed to investigate the effect of platelet-rich plasma (PRP) and platelet-rich fibrin matrix (PRFM) on the healing of vertical medial meniscal tears in a rabbit model. The study was conducted on 72 New Zealand mature rabbits aged more than 6 months. Rabbits were randomly assigned to six groups: control (C) group, meniscal repair (MR) group, PRP group, PRFM group, MR+PRP group, and MR+PRFM group, with 12 rabbits in each group. A 5-mm full-thickness vertical tear was created in the avascular zone of the medial meniscus corpus in the right knee of all rabbits. The respective treatment for each group was given to the meniscal tear in each rabbit. Histological evaluation of healing was performed 6 and 12 weeks after surgery. Defect filling and collagen formation remained low in the C group. However, in all other groups, there was no significant difference in the 6th week. In the 12th week, similar results as those obtained in the 6th week were obtained. In the C group, there was a difference in defect filling and cell type. This difference was that the defect filling and collagen formation remained low in the 12th week. No significant difference was observed between MR, MR + PRP and MR + PRFM groups. The MR group significantly differed from the other groups in the defect-filling rate and cell type; however, the use of PRP and PRFM did not provide an obvious benefit. The contradictory results obtained in previous studies emphasize the need for further research on the use of PRP in meniscal recovery and repair. We believe that if surgery is indicated, repair is absolutely necessary to improve the healing of the tissue in meniscal tears. Studies using human meniscal tissue for meniscal injury and those that evaluate clinical applications of PRP are warranted.