Radial Meniscal Tears Research Articles

Suture Tying Force for Cut-Out during Radial Meniscus Tear Repair: A Biomechanical Evaluation of Failure Loads during the Knot-Tying Process.

The purpose of the study was to determine average tensile forces resulting in suture failure while tying a knot during repair of complete radial meniscus tears and to compare the failure tensile force based on meniscus tissue location: the peripheral (red-red) versus inner (white-white). This study was designed as a cadaveric biomechanical study using 24 menisci harvested from fresh frozen cadaveric knees with midbody radial tears. Tears were repaired using 2-0 nonabsorbable suture in both the inner meniscus and the peripheral meniscus. A force gauge was used to measure the tension of a surgeon's knot until failure of either the suture or the meniscus tissue. Statistical analysis was performed comparing suture failure tensile forces between inner and peripheral sutures using 2-sample t test. Suture repairs primarily failed due to meniscal tissue cut-out after suture tensioning (96%). There was no statistical difference in failure mode between medial and lateral meniscus for both the inner (100% cut-out) and the peripheral (92% cut-out; P = 0.703) sutures. The peripheral sutures failed as significantly higher loads (54 ± 26 N) than the inner sutures (36 ± 11 N, P = 0.006). The peripheral meniscus tissue tolerated significantly higher tension at failure (36 ± 7 N) than the inner meniscus (26 ± 7 N, P < 0.001). When tying parallel sutures to repair a radial meniscus tear, suture tensile forces above 30 N may tear through meniscus tissue. Surgeons should not use suture tying forces above 30 N when repairing radial meniscus tears with parallel sutures. The peripheral meniscus can withstand higher knot-tying forces than the inner meniscus, so surgeons should consider tying the peripheral suture before the inner suture.

Meniscus Ripstop Stitches: A Useful Technique for Arthroscopic Repair of Challenging Radial Tears of the Meniscus

Radial meniscal tears can be challenging to address and require advanced arthroscopic techniques for satisfactory repair. When radial tears occur in older patients, the surgeon often encounters suboptimal tissue integrity that presents its own challenges. Incorporating ripstop sutures in tie-grip repair constructs for radial tears has been documented in the literature with favorable biomechanical properties. This Technical Note and accompanying video present a reproducible method for incorporating tie-grip and mobile ripstop stitches to fortify traditional meniscal repair configurations for radial tears. This technique augments the biomechanical strength of repair and may prove useful in poor tissue quality and areas of small focal deficiency, especially in scenarios with repairable but degenerative meniscal tissue. This is particularly relevant considering many repairs fail due to pull-through of sutures within the meniscal tissue.

Poster 303: Outcomes Following Repair of Radial Meniscus Tears Compared to Bucket Handle Meniscus Tears

Objectives: Preserving the meniscus has become a priority in managing meniscal tears with advancement of meniscus repair techniques. Meniscal repair, as opposed to partial meniscectomy, reduces risk of development and progression of knee osteoarthritis. Radial meniscus tears have traditionally been associated with a poor prognosis because they occur perpendicular to circumferential meniscal fibers, compromising hoop tension. Advances in surgical technique and biologic augmentation have facilitated repair of these complex injuries. The purpose of this study was to compare post-operative complication and surgical revision rates in patients who underwent repair of a radial meniscus tear versus bucket-handle meniscus tear. We hypothesized the outcomes of repair of radial meniscus tear would be similar to a matched group of patients who underwent repair of a bucket handle meniscus tear. Methods: A retrospective study was performed to identify patients who underwent repair of radial meniscus tear. Chart review was performed for 1506 patients who underwent meniscus repair from 2012 to 2019, and demographic information, type of meniscus tear, concomitant ACL reconstruction, post-operative complications, repeat surgeries, and failure at the repair site were detailed in a database. Patients who underwent repair of a radial tear were matched with patients who underwent repair of a bucket-handle tear based on sex, age (within 5 years), BMI (within 5 kg/m2), meniscus laterality, and concomitant ACL reconstruction. Isolated meniscus repairs were augmented with platelet rich plasma (PRP). Results: Fifty patients (age, 31.8 ± 15.2 years; BMI, 30.2 ± 6.4 kg/m2) were identified who underwent a radial meniscus tear repair. Of these patients, 16 (32.0%) were female and 23 (46.0%) underwent concomitant ACL reconstruction. Complications including recurrent swelling, stiffness, persistent pain, and repeat injury were reported in 15 patients (30.0%). Six patients underwent repeat surgery (12.0%). Four repeat surgical patients, who had previously undergone meniscus repair and concomitant ACL reconstruction, were found to have an intact radial repair at the time of second surgery, and underwent repeat surgery for a reason unrelated to the radial tear repair (e.g. cyclops lesion, synovectomy, new meniscus tear). Two patients had a radial tear repair failure that required surgical revision (4.0%). Radial tear repair patients who underwent concomitant ACL reconstruction differed significantly from those who did not only in age (ACL group, 26.0 ± 10.9 y; non-ACL group, 36.6 ± 16.7 y; p = 0.03). There were no significant differences in post-operative complications, repeat surgeries, or failures between the radial and bucket-handle tear repair patients. Conclusions: Repair of radial meniscus tears with contemporary techniques and biological enhancement with either ACL reconstruction or PRP can be expected to have similar outcomes to repairs of bucket handle meniscus tears.

Arthroscopic Repair of radial meniscal tear by Double Vertical cross sutures through Inside-Out technique

Arthroscopic Repair of radial meniscal tear by Double Vertical cross sutures through Inside-Out technique

Arthroscopic Repair of a Lateral Meniscus Oblique Radial Tear

Background: Lateral meniscal oblique radial tears (LMORTs) are the most common type of lateral meniscal tears and occur concomitantly with anterior cruciate ligament (ACL) tears in up to 12% of cases. Four types of LMORTs have been classified in the literature based on proximity to the meniscal root and extent of the tear. Type 1 and 2 LMORTs represent partial and complete posterior root tears less than 10 mm from the root insertion. Type 3 and 4 LMORTs are partial and complete posterior radial meniscus tears greater than 10 mm from the root insertion. Indications: Type 3 and 4 LMORTs can and should be addressed with an all-inside side-to-side repair at the time of ACL reconstruction. LMORTs that are not repaired at the time of ACL reconstruction can contribute to persistent instability and meniscal extrusion. Technique Description: Diagnostic arthroscopy is performed to evaluate the posterior aspects of both the medial and lateral meniscus. The medial leaflet is commonly flipped into the notch and scarred to ACL remnant. After identifying and isolating the medial leaflet, an arthroscopic suture passer is used to pass a suture from inferior to superior through the medial leaflet. A second suture is passed from inferior to superior through the lateral leaflet. This is used to shuttle the suture pass through the medial leaflet to the bottom of the meniscus, where it can be tied in a horizontal mattress fashion. The sutures are tied down with aide of an arthroscopic knot pusher. A second set of sutures is passed and used to shuttle a second suture that would be tied posterior to the first suture, again in a horizontal mattress fashion. This allows reduction of the fragments in apposition across the tear. Postoperatively, patients are allowed range of motion from 0° to 90° and to toe touch weightbearing for the first 4 weeks. Patients are advanced to weightbearing as tolerated at 5 weeks. Typical return to sport ranges from 6 to 9 months postoperatively. Results: Results have been published for 2-year outcomes of type 3 and 4 LMORT repairs and have demonstrated persistent improved patient-reported outcomes as well as healing rates that are greater than 80% and in some series approach nearly 100%. Discussion/Conclusion: Arthroscopic all-inside side-to-side surgical repair is a durable and reliable treatment option for patients presenting for ACL reconstruction with concomitant type 3 or 4 LMORT. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Meniscal Radial Tears: A Classification System Based on Tear Morphology

Appropriate management of radial meniscal tears is complex, with continued efforts focused on optimizing diagnostic methods for identification to help dictate treatment, especially as surgical indications for repair have expanded, coupled with improvements in surgical techniques and instrumentation. Currently, no standardized classification system for radial meniscal tears exists, limiting the ability to accurately characterize injury patterns and guide surgical decision-making.

Augmentation with Bone Marrow Aspirate Harvested from the Iliac Crest for Horizontal or Radial Meniscal Tears Yields Favorable Healing Rates in Magnetic Resonance Imaging and Clinical Outcomes

Augmentation with Bone Marrow Aspirate Harvested from the Iliac Crest for Horizontal or Radial Meniscal Tears Yields Favorable Healing Rates in Magnetic Resonance Imaging and Clinical Outcomes

Repair of a Radial Tear of the Meniscus Augmented With a Biocomposite Scaffold

Meniscal tears are a common musculoskeletal pathology in the United States, affecting 61 in every 100,000 people. Surgical repair is indicated for certain tear patterns to reduce the risk of joint degeneration, normalize contact forces in the knee, and help restore normal knee kinematics. However, radial meniscus tear repairs fail to completely heal 38% of the time due to tear characteristics, biology, surgical technique, and inadequate rehabilitation. Recent efforts have incorporated biological augmentation to enhance the healing potential of the meniscus. The BioBrace is a biocomposite scaffold designed to mechanically reinforce tissue and biologically enhance healing. The purpose of this article is to describe an all-inside, meniscal radial tear repair augmented with BioBrace.

Hybrid Repair of a Medial Meniscus Mid-Body Radial Tear

Background: Meniscal radial tears are associated with altered contact mechanics, as they have the potential to disrupt the meniscal hoop stress mechanism. In prior studies, radial tears are associated with higher grade of cartilage damage, as well as higher rate and severity of meniscal extrusion in knees with a radial tear relative to other types of tears. Improved understanding of the meniscus biological potential together with modern developments in surgical technique has paved the way for the current emphasis on repairing even radial tears. Indication: Large or complete radial tears of the meniscus without prohibitive joint space narrowing or severe cartilage damage. Technique Description: A hybrid technique of meniscal radial repair is described, combining (1) 2 transtibial pullout cinch-loop sutures, (2) 2 inside-out vertical rip-stop sutures and 2 oblique sutures in a “cross-tag” configuration, and (3) 1 horizontal mattress all-inside suture. The repair is biologically augmented with a notch marrow-venting procedure. Results: Recent evidence has demonstrated significant biomechanical benefit in terms of increased load to failure and construct strength when adding transtibial tunnel augmentation to radial repairs. In addition, rip-stop sutures decrease the chance of cut-out relative to nonreinforced repairs. Those biomechanical advancements are reflected in excellent patient-reported outcomes as well as healing rates following radial repair. Discussion/Conclusion: We present a hybrid technique encompassing the most biomechanically effective novel radial repair techniques, backed by excellent clinical outcomes following radial repair in the current literature. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Meniscal Circumferential Fiber Augmentation: A Biomechanical Arthroscopic Meniscal Repair Technique

Radial tears of the human knee meniscus result in the loss of circumferential hoop stress and are highly correlated with knee degeneration. Although a variety of surgical techniques are available to repair radial meniscal tears, including inside-out, outside-in, and all-inside techniques, conventional repair techniques focus only on stabilizing the damaged portion. This Technical Note describes a biomechanical meniscus repair technique of meniscal circumferential fiber augmentation, concomitant with conventional repair, to promote meniscal healing from a biomechanical perspective.

COLLAGEN MATRIX MENISCAL WRAPPING REDUCES CONTACT PRESSURES IN MENISCAL REPAIR: A FINITE ELEMENT ANALYSIS STUDY

AbstractINTRODUCTIONTo preserve knee function and reduce degenerative, meniscal tears should be repaired where possible. Meniscal wrapping with collagen matrices has shown promising clinical outcome (AAOS meniscal algorithm), however there is limited basic science to support this.AIMto model the contact pressures on the human tibial plateau beneath a (1) a repaired radial meniscal tear and (2) a wrapped and repaired radial meniscal tear.METHODOLOGYComplete anterolateral radial tears were formed across 4 lateral human menisci, before repairing with ‘rip-stop’ H sutures using 2mm Arthrex Meniscal Suture tape. This was then repeated with the addition of a ChondroGide collagen matrix wrapping. From this experimental setup a finite element (FE) analysis model was construted.FE models of the two techniques (i) suture alone and (ii) suture and collagen-matrix wrap, were then modelled; bone was linear elastic, articular cartilage was a hyperelastic Yeoh model, and a linear elastic and transversely isotropic material model for the meniscus.The contact areas of the articulating surfaces, meniscus kinematics, and stress distribution around the repair were compared between the two systems.RESULTSMeniscal suture-tape repair had higher local stresses and strains (σ_max=51 MPa ε_max=25%) around the repair compared to with Collagen wrapping (σ_max=36.6MPa ε_max=15%). Radial displacement and pressure on the meniscal contact surfaces were higher in the suture only repair.CONCLUSIONCollagen-matrix wrapping strengthens the repair, reducing local peak stresses and strains around the suture-tape. This could reduce the chance of suture-tape pull-out and subsequent repair failure.

Anterolateral Radial Meniscus Tear Repair using Traction Suture and Super-Hashtag Technique

Radial meniscus tears occur commonly as traumatic tears in younger patients, as well as in association with concomitant degenerative changes. Traditional management of these tears has centered around partial meniscectomy; however, there has been a more recent trend toward preserving the meniscus and attempting repair. Because of the gapping and displacement that frequently occurs with these tears, repair is often challenging and is done under high amounts of tension. The following article describes a technique using a traction suture to aid in maintaining reduction throughout repair. This is followed by the use of a combination of techniques to form a “super-hashtag” configuration of both vertical and horizontal mattress sutures, leading to a secure repair under little tension.

Poster 123: Biomechanical Comparison of Four All-inside Meniscus-Based Repairs to Radial Tears of Human Cadaveric Lateral Menisci

Objectives: Meniscal injuries are among the most common orthopedic injuries in the United States. Radial meniscus tears were historically treated with partial meniscectomy, often leading to poor outcomes. Radial tear repair preserves meniscal tissue, may delay knee degeneration, and leads to better long-term outcomes. Repair techniques for radial tears vary and should be evaluated for differences in biomechanical properties and failure mechanisms. All-inside, meniscus-based suture repairs have shorter operating times, minimize risk of nerve injury, and are increasingly possible with novel devices. Our objective was to evaluate the strength based on load-to-failure of four all-inside meniscus-based repair techniques for radial tears in human cadaveric lateral menisci. We chose two techniques that bridged the tear directly – the Double Vertical (DV, Figure 1) and Double Vertical Cross (DVX, Figure 2). We chose two other techniques that added horizontal reinforcing stitches to engage the bridging stitches – the All-inside Rebar (AR, Figure 3) and our novel Oblique Box (OB, Figure 4). We hypothesized that AR and OB would have higher load to failure than DV and DVX. Methods: 36 fresh-frozen human adult lateral menisci were randomized into four groups of nine. Dissection, repair, and testing were completed one meniscus at a time to minimize the time period from thawing to testing. Each meniscus was dissected from its tibial bone block, and a complete radial tear was created at the midbody of the meniscus. Suture repairs were performed using 2-0 braided suture and a straight needle. Menisci were repaired using the DV, DVX, AR, and OB techniques with meniscus- based suturing to simulate the all-inside, meniscus-based approach. All suture dimensions were standardized as indicated on Figures 1-4, and all knots were tied on the superior surface of the menisci. The suture patterns for all repair types used loops that passed above the superior and below the inferior surfaces of the meniscus. The DV repair used two sutures in loops perpendicular to the tear. DVX used two sutures in loops that crossed over the tear. AR used two sutures in loops parallel to the tear acting as reinforcing rebar and two bridging sutures perpendicular to the tear and outside the rebar sutures. OB used two sutures to create a trapezoidal reinforcing box on either side of the tear and two bridging sutures in loops perpendicular to the tear and inside the box. The repaired menisci were loaded on an Instron 5944 test frame with 2 kN load cell using custom clamps. They underwent cyclic loading of 5-30 N for 500 cycles at 10 mm/min, a 30-minute resting period, and a single trial of load-to-failure at 10 mm/min. The ultimate load at failure was analyzed via one-way ANOVA with Tukey’s test for pairwise comparisons and significance set at p&lt;0.05. Results: Failure occurred due to suture cutout in all specimens. Repair constructs that lacked a reinforcing-type suture (DV and DVX) cut through or “cheese-wired” at lower loads than repairs with reinforcing sutures (AR and OB). Mean ± standard deviation ultimate load values for each repair group were 60 N ± 24.5 for DV, 58 N ± 17.4 for DVX, 168 N ± 33.9 for AR, and 105 N ± 9.0 for OB. The ultimate load for all repair techniques were significantly different from each other by Tukey’s test with the exception of the DV and DVX comparison. These results show that reinforcing vertical suture meniscus repairs with some type of horizontal suture (e.g. AR or OB) significantly increases ultimate load at failure for all-inside, meniscus-based techniques. Conclusions: In a cadaveric lateral meniscus model, all-inside radial repairs using rebar suture, or horizontal suture reinforcing techniques, had higher ultimate load at failure and reduced risk of “cheese wiring”. The AR repair sustained the highest ultimate load at failure, nearly 3x stronger than the two non-reinforcing type repair constructs. These data may provide useful information for surgeons during repair to radial meniscus tears. Future biomechanical study should compare all-inside vs. inside-out repairs to maximize patient outcomes. Cross reference of repair patterns with clinical outcomes using the prospective registry data may support optimal surgical techniques to improve meniscus repair outcomes.

Improved Outcomes After Reinforced Radial Meniscus Repair Augmented With Bone Marrow Aspirate Concentrate

To assess clinical outcomes of patients who have undergone surgical repair of radial meniscal tears with reinforced suture bar (rebar) technique augmented with bone marrow aspirate concentrate. This is a retrospective study of a single fellowship-trained sports medicine surgeon's experience on all patients who underwent a reinforced repair (rebar) of a radial meniscus tear from November 2016 to 2018, with a minimum of 12-month follow-up. Lysholm scores, IKDC (International Knee Documentation Committee) Subjective Knee Form scores, and Tegner scalewere collected postoperatively at periods for at least 1 year and retrospectively studied. Patients were followed for an average of 36.3 ± 25.0 months [range: 12.0-69.0 months]. Pain scores improved from 6.1 ± 2.1 to 0.4 ± 1.4 at 1 year (P < .001). IKDC Subjective Knee Form scores improved from 63 ± 26 to 90 ± 13 (P= .021). Lysholm scores improved from 64 ± 28 to 94 ± 9 (P= .025). Based on a calculated minimal clinical important difference (MCID) of 1.5, 100% of patients had improvement above the MCID. In addition, 88% of patients had a 1-year IKDC Subjective Knee Form score above the patient acceptable symptomatic state. Preoperative Tegner activity scale improved from 3 ± 1.5 to 8 ± 2.6 (P= .007). Patients returned to their preinjury activity with little difference in the Tegner activity scale when we compared preinjury and 1-year postoperative (8.1 ± 1.3 vs 8.0 ± 2.6 respectively, P= .317). The rebar repair technique for radial meniscus tears, with bone marrow aspirate concentrate augmentation, showed improved outcomes in both pain and function at minimum follow-up of 12 months. Patients were able to return to a high preinjury activity level by 1 year, and 100% of patients had improvement above the MCID and 88% met patient acceptable symptomatic state. Level IV, therapeutic case series.

Meniscal Extrusion: Diagnosis, Etiology, and Treatment Options.

The concept of meniscal extrusion has recently been recognized as a hallmark of meniscus dysfunction. This review examines contemporary literature regarding the pathophysiology, classification, diagnosis, treatment, and future directions for investigation regarding meniscus extrusion. Meniscus extrusion, defined as >3 mm of radial displacement of the meniscus, leads to altered knee biomechanics and accelerated knee joint degeneration. Meniscus extrusion has been associated with degenerative joint disease, posterior root and radial meniscal tears, and acute trauma. Meniscus centralization and meniscotibial ligament repair have been proposed as techniques to address meniscal extrusion with promising biomechanical, animal model, and early clinical reports. Further studies on the epidemiology of meniscus extrusion and associated long-term nonoperative outcomes will help to elucidate its role in meniscus dysfunction and resultant arthritic development. Understanding and appreciation for the anatomic attachments of the meniscus will help to inform future repair techniques. Long-term reporting on the clinical outcomes of meniscus centralization techniques will yield insights into the clinical significance of meniscus extrusion correction.

Biomechanical effects of medial meniscus radial tears on the knee joint during gait: A concurrent finite element musculoskeletal framework investigation.

The biomechanical variation in the knee during walking that accompanies medial meniscal radial tears stemming from knee osteoarthritis (OA) has not been explored. This study introduced a finite element musculoskeletal model using concurrent lower limb musculoskeletal dynamics and knee joint finite element analysis in a single framework and expanded the models to include knees with medial meniscal radial tears and total medial meniscectomy. The radial tears involved three locations: anterior horn, midbody, and posterior horn with grades of 33%, 50%, and 83% of the meniscus width. The shear and hoop stresses of the tear meniscus and tibial cartilage contact load, accompanying tears, and postmeniscectomy were evaluated during the stance phase of the gait cycle using the models. In the 83% width midbody tear group, shear stress at the end of the tear was significantly greater than in the intact meniscus and other tear groups, and the maximum shear stress was increased by 310% compared to the intact meniscus. A medial meniscus radial tear has a much smaller effect on the tibial cartilage load (even though in the 83% width tear, the cartilage/total load ratio increased by only 9%). However, the contact force on the tibial cartilage with total postmeniscectomy was increased by 178.93% compared with a healthy intact meniscus, and the peak contact pressure after meniscectomy increased from 11.94 to 12.45 MPa to 17.64 and 13.76 MPa, at the maximum weight acceptance and push-off, respectively. Our study shows that radial tears with larger medial meniscus widths are prone to high stress concentrations at the end of the tears, leading to the potential risk of complete meniscal rupture. Furthermore, although the tears did not change the cartilage load distribution, they disrupted the circumferential stress-transmitting function of the meniscus, thus greatly increasing the likelihood of the onset of knee OA. The significant increase in the tibial cartilage load with total postmeniscectomy indicates a potential risk of OA flare-ups. This study contributes to a better understanding of meniscal tear-induced OA biomechanical changes during human activities and offers some potential directions for surgical guidance of meniscectomies and the prophylaxis and treatment of OA.

Combined Meniscus Repair and Anterior Cruciate Ligament Reconstruction

AbstractMeniscal tear patterns associated with anterior cruciate ligament (ACL) tears, such as root tears and ramp lesions are common but less easily recognized on magnetic resonance imaging (MRI) compared with a complete radial tear or a locked bucket-handle tear. Timely treatment of these tears improves outcomes in the setting of ACL reconstruction. While physical examination does not enable a definitive diagnosis of meniscal root tears and ramp lesions, high-grade laxity, including a 3+ Lachman and 3+ pivot shift, should raise suspicions for these tear patterns. MRI allows visualization of both root tears and ramp lesions, although the gold standard for diagnosis is probing at the time of arthroscopy due to a high false-negative rate on MRI. Up to 17% of patients with an ACL tear have a lateral meniscal root tear; a contact mechanism and increased posterior slope are both associated with a greater incidence of lateral meniscal root tears and these are repaired with a tunnel technique. Meniscal ramp lesions occur in up to 41% of patients with ACL tears due to a contact mechanism, and we prefer repair with an inside-out technique. More than 60% of complete radial meniscal tears occur in the setting of ACL tears and are preferentially repaired with a hashtag technique for minimally separated tears and a 2-tunnel technique combined with an inside-out repair for more severe tears. Bucket-handle tears are more common in the setting of chronic ACL deficiency; concurrent with ACL reconstruction urgent meniscal repair with an inside-out technique is the gold standard, which allows for precise approximation of the tear with multiple points of fixation for improved biomechanical performance. It is critical to identify and treat these tears during ACL reconstruction because of their role as secondary stabilizers and for long-term chondral protection.

Biomechanics of the medial meniscus in the osteoarthritic knee joint.

BackgroundIncreased mechanical loading and pathological response of joint tissue to the abnormal mechanical stress can cause degradation of cartilage characteristic of knee osteoarthritis (OA). Despite osteoarthritis is risk factor for the development of meniscal lesions the mechanism of degenerative meniscal lesions is still unclear. Therefore, the aim of the study is to investigate the influence of medial compartment knee OA on the stress state and deformation of the medial meniscus.MethodsThe finite element method was used to simulate the stance phase of the gait cycle. An intact knee model was prepared based on magnetic resonance scans of the left knee joint of a healthy volunteer. Degenerative changes in the medial knee OA model were simulated by nonuniform reduction in articular cartilage thickness in specific areas and by a decrease in the material parameters of cartilage and menisci. Two additional models were created to separately evaluate the effect of alterations in articular cartilage geometry and material parameters of the soft tissues on the results. A nonlinear dynamic analysis was performed for standardized knee loads applied to the tibia bone.ResultsThe maximum von Mises stress of 26.8 MPa was observed in the posterior part of the medial meniscus body in the OA model. The maximal hoop stress for the first peak of total force was 83% greater in the posterior horn and only 11% greater in the anterior horn of the medial meniscus in the OA model than in the intact model. The reduction in cartilage thickness caused an increase of 57% in medial translation of the medial meniscus body. A decrease in the compressive modulus of menisci resulted in a 2.5-fold greater reduction in the meniscal body width compared to the intact model.ConclusionsHigher hoop stress levels on the inner edge of the posterior part of the medial meniscus in the OA model than in the intact model are associated with a greater medial translation of the meniscus body and a greater reduction in its width. The considerable increase in hoop stresses shows that medial knee OA may contribute to the initiation of meniscal radial tears.

An Arthroscopic-Assisted Radial Meniscal Tear Repair Using Reinforced Suture Tape Rebars and Suture Tapes

A radial tear of the meniscus can lead to significant loss of meniscus function, resulting in deleterious cartilage changes. Repair of radial meniscus tears has several challenges, including suture pull-out, which can reduce healing success. We present an arthroscopic repair technique in a complete radial lateral meniscus tear using vertical reinforced bars (rebar) of suture tapes to reduce suture pull-out and approximate the radial tear.

Tibiofemoral Contact Mechanics After Horizontal or Ripstop Suture in Inside-Out and Transtibial Repair for Meniscus Radial Tears in a Porcine Model

To compare tibiofemoral contact mechanics after horizontal or ripstop (horizontal plus vertical) sutures in inside-out and transtibial repair for meniscal radial tears with 10 porcine knees in each group. Ten matched pairs of porcine knees were tested under a 1500-N axial compressive load at 0°, 30°, 60°, and 90° of knee flexion. Each knee underwent 4 testing conditions consecutively: (1) intact, (2) medial meniscal radial tear, (3) horizontal suture repair configuration, and (4) ripstop suture repair configuration. Tekscan sensors measured tibiofemoral contact pressure and contact area in the medial and lateral compartments. All repair groups improved their contact mechanics when compared with the tear state among all flexion angles analyzed (all P < .05). Furthermore, ripstop sutures with both inside-out and transtibial repairs restored intact knee contact area and pressures (peak and mean) in the medial compartment at all flexion angles, whereas the horizontal sutures alone failed to do so for contact pressures at 60° and 90° and for contact surface areas at all flexion angles. However, the aforementioned parameters were not significantly different between inside-out sutures and transtibial sutures, regardless of horizontal or ripstop configuration (P > .05). Radial tears of the meniscus in a porcine model significantly decreased medial contact area and increased mean and peak contact pressure. Both inside-out and transtibial ripstop repairs for radial tears aid in restoring intact tibiofemoral contact mechanics at all assessed knee flexion angles. Our results suggest that both inside-out and transtibial ripstop repairs for radial tears can restore tibiofemoral contact mechanics to the intact state. Since the study were performed in an open fashion porcine model, the results should be carefully used in clinical practices, and the efficacy of the techniques through arthroscopic method should be further explored.