Nonanatomic Location of the Posterior Horn of a Medial Meniscal Autograft Implanted in a Cadaveric Knee Adversely Affects the Pressure Distribution on the Tibial Plateau

Background: Some authors have suggested that the semimembranosus tendon is involved in the pathophysiology of ramp lesions. This led us to conduct a gross and microscopic analysis of the posterior horn of the medial meniscus and the structures inserted on it. Hypothesis: (1) The semimembranosus tendon has a tendinous branch inserting into the posterior horn of the medial meniscus, and (2) the meniscotibial ligament is inserted on the posteroinferior edge of the medial meniscus. Study Design: Descriptive laboratory study. Methods: In total, 14 fresh cadaveric knees were dissected. From each cadaveric donor, a stable anatomic specimen was harvested en bloc, including the medial femoral condyle, medial tibial plateau, whole medial meniscus, cruciate ligaments, joint capsule, and distal insertion of the semimembranosus tendon. The harvested blocks were cut along the sagittal plane to isolate the distal insertion of the semimembranosus tendon on the posterior joint capsule and the posterior horn of the medial meniscus in a single slice. Histological slides were made from these samples and analyzed under a microscope. Results: In all knees, gross examination revealed a direct branch of the semimembranosus and a tendinous capsular branch ending behind the posterior horn of the medial meniscus. This capsular branch protruded over the joint capsule, over the meniscotibial ligament below and the meniscocapsular ligament above, but never ended directly in the meniscal tissue. The capsular branch was 14.3 ± 4.4 mm long (mean ± SD). The direct tendon inserted 11 ± 2.8 mm below the articular surface of the tibial plateau. The meniscotibial ligament inserted on the posteroinferior edge of the medial meniscus, and the meniscocapsular ligament insertion was on its posterosuperior edge. Highly vascularized adipose tissue was found, delimited by the posterior horn of the medial meniscus, meniscotibial ligament, meniscocapsular ligament, and capsular branch of the semimembranosus tendon. Conclusion: In all knees, our study found a capsular branch of the semimembranosus tendon inserted behind the medial meniscus. The meniscotibial ligament was inserted on the posteroinferior edge of the medial meniscus. Histological analysis of this area revealed that this ligament inserted differently from the insertion previously described in the literature. Clinical Relevance: This laboratory study provides insight into the pathophysiology of ramp lesions frequently associated with anterior cruciate ligament injury. To restore anatomy, it is mandatory to reestablish meniscotibial ligament continuity in ramp repairs.

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Pressure distributions on the medial tibial plateau after medial meniscal surgery and tibial plateau levelling osteotomy in dogs

Veterinary and Comparative Orthopaedics and Traumatology ◽

10.3415/vcot-06-12-0099 ◽

2008 ◽

Vol 21 (01) ◽

pp. 8-14 ◽

Cited By ~ 38

Author(s):

A. Pozzi ◽

A. S. Litsky ◽

J. Field ◽

D. Apelt ◽

C. Meadows ◽

...

Keyword(s):

Pressure Distribution ◽

Tibial Plateau ◽

Cruciate Ligament ◽

Testing Machine ◽

Axial Loading ◽

Fold Increase ◽

Cranial Cruciate Ligament ◽

Pressure Distributions ◽

Before And After ◽

Meniscal Surgery

Summary Objective: To evaluate the effect of medial meniscal release (MMR) and medial, caudal pole hemimeniscectomy (MCH) on pressure distribution in the cranial cruciate ligament (CCL) deficient canine stifle, and with tibial plateau levelling osteotomy (TPLO). Animals: Twelve adult dogs. Methods: In experiment one, six pairs of cadaveric canine stifles with an intact CCL were axially loaded with a servo-hydraulic material testing machine and pressure distributions were mapped and quantified using pressure sensitive films. Axial loading of each joint was then repeated following MMR, and again after MCH. In experiment two, six pairs of cadaveric canine stifles with or without TPLO were tested before and after CCL transection, and each MMR and MCH procedure using the same methods of experiment 1. Results: In experiment one, MMR and MCH had significant effects on the pressure distribution resulting in a 2.5-fold increase in the percentage of surface area with pressure higher than 10 MPa. In experiment two, CCL transection resulted in a significant change in pressure distribution only in the stifle without TPLO (P<0.05). Both MMR and MCH resulted in a 1.7-fold increase in the percentage of area with peak pressure in the stifle with TPLO (P<0.05). Conclusions: Meniscal surgery results in a change in pressure distribution and magnitude within the medial compartment of the stifle. Clinical relevance: Compromised function of the meniscus by either MMR or MCH result in stress concentration which may predispose to osteoarthritis.

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Correlation Between CT Images of Lateral Plateau and Lateral Meniscus Injuries in Patients With Schatzker II Tibial Plateau Fractures：A Retrospective Study

10.21203/rs.3.rs-543373/v1 ◽

2021 ◽

Author(s):

Pu Ying ◽

Lei Zhu ◽

Wenge Ding ◽

Yue Xu ◽

Xiaowei Jiang ◽

...

Keyword(s):

Tibial Plateau ◽

Lateral Meniscus ◽

Ct Images ◽

Tibial Plateau Fractures ◽

Posterior Horn ◽

Operating Point ◽

Optimal Operating ◽

Meniscus Injury ◽

Lateral Plateau ◽

Meniscus Injuries

Abstract Background: There is a great deal of controversy on whether routine MRI examination is needed for fresh fractures while the vast majority of patients with tibial plateau fractures receive preoperative X-ray and CT examinations. The purpose of the study was to analyze the exact correlation between CT images of lateral plateau and lateral meniscus injuries in Schatzker II tibial plateau fractures. Methods: Two hundred and ninety-six Schatzker II tibial plateau fracture patients from August 2012 to January 2021 in two trauma centers were enrolled for the analysis. According to the actual situation during open reduction internal fixation (ORIF) and knee arthroscopic surgery, patients were divided into meniscus injury (including rupture, incarceration, etc.) and non-meniscus injury groups. By measuring the value of both lateral plateau depression (LPD) and lateral plateau widening (LPW) of lateral tibial plateau on the coronary CT images, the correlation of which and lateral meniscus injury was analyzed. Meanwhile, the relevant receiver operating characteristic (ROC) curve was drawn to evaluate the optimal operating point of these two indicators which could predict meniscus injury. Results: Meniscus injury group mainly showed injuries involving the mid-body and posterior horn of the meniscus (98.1%, 157/160). The average LPD was 13.2 ± 3.2 mm, while the average value of the group without meniscus injury was 9.4 ± 3.2 mm. The difference was statistically significant (P < 0.05). The average LPW was 8.0 ± 1.4 mm and 6.8 ± 1.6 mm in two groups with a significant difference (P < 0.05). The optimal operating point of LPD and LPW was 7.9 mm (sensitivity-95.0%, specificity-58.8%, area under the curve (AUC-0.818) and 7.5 mm (sensitivity-70.0%, specificity-70.6%, AUC-0.724), respectively. Conclusions: The mid-body and posterior horn of lateral meniscus injury is more likely to occur in patients who had Schatzker II tibial plateau fractures when LPD > 7.9 mm and/or LPW > 7.5 mm on CT manifestations and these findings will definitely provide guidance for orthopedic surgeons in treating such injuries. During the operation, more attention should be paid to the treatment of the meniscus and full consideration is needed be taken to situations such as meniscus rupture, incarceration and other possible fracture reduction difficulties, poor vertical line, etc., in order to achieve better surgical results.

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Tibial Plateau Cysts at the Meniscal Root Insertions: Incidence and Association

The Duke Orthopaedic Journal ◽

10.5005/jp-journals-10017-1007 ◽

2011 ◽

Vol 1 (1) ◽

pp. 45-49 ◽

Cited By ~ 3

Author(s):

Manjiri M Didolkar ◽

Emily N Vinson

Keyword(s):

Retrospective Study ◽

Tibial Plateau ◽

Posterior Horn ◽

Anterior Horn ◽

Level Of Evidence ◽

Meniscal Root ◽

Knee Mri ◽

Institutional Review ◽

Level Ii ◽

Meniscal Pathology

ABSTRACT Background The purpose of this study is to identify a possible relationship between high T2-signal cyst-like foci in the tibial plateau at the meniscal root insertions and meniscal pathology. Methods Institutional review board approval was obtained for this retrospective study. HIPAA compliance was maintained throughout this study. Two radiologists reviewed 200 knee MRI examinations for tibial plateau cysts at the meniscal root insertion sites; meniscal tears and intrameniscal cysts were also noted. The knee MRI examinations were also evaluated for articular cartilage abnormalities of the medial and lateral tibial plateaus. Results Of the 200 knee examinations, 83(41.5%) demonstrated medial meniscal pathology and 47(23.5%) demonstrated lateral meniscal pathology. Twenty (10%) demonstrated cysts in at least one of the described locations; two knees had cysts in two separate locations. four (2%) examinations had cysts at the anterior horn medial meniscal insertion, and all four (100%) had medial meniscal pathology (p = 0.028). Eleven (5.5%) examinations demonstrated cysts at the posterior horn medial meniscal insertion, and eight (72.7%) had medial meniscal pathology (p = 0.031). five (2.5%) examinations demonstrated cysts at the anterior horn lateral meniscal insertion, and one (20%) had lateral meniscal pathology (p = 0.374). Two (1%) examinations demonstrated cysts at the posterior horn lateral meniscal insertion, and one (50%) had lateral meniscal pathology (p = 0.852). Conclusions Cysts at the meniscal insertions are often seen on knee MRI. Cysts located at the insertions of the medial meniscus have a statistically significant association with meniscal pathology. Level of evidence Level II, retrospective study with development of diagnostic criteria on the basis of consecutive patients.

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Correlation of Biomechanical Alterations under Gonarthritis between Overlying Menisci and Articular Cartilage

Applied Sciences ◽

10.3390/app10238673 ◽

2020 ◽

Vol 10 (23) ◽

pp. 8673 ◽

Cited By ~ 1

Author(s):

Johannes Pordzik ◽

Anke Bernstein ◽

Julius Watrinet ◽

Hermann O. Mayr ◽

Sergio H. Latorre ◽

...

Keyword(s):

Articular Cartilage ◽

Applied Load ◽

Structural Changes ◽

Tibial Plateau ◽

Biomechanical Properties ◽

Posterior Horn ◽

Joint Surfaces ◽

Significant Difference ◽

Instantaneous Modulus ◽

Biomechanical Changes

Just like menisci, articular cartilage is exposed to constant and varying stresses. Injuries to the meniscus are associated with the development of gonarthritis. Both the articular cartilage and the menisci are subject to structural changes under gonarthritis. The aim of this study was to investigate biomechanical alterations in articular cartilage and the menisci under gonarthritis by applying an indentation method. The study assessed 11 menisci from body donors as controls and 21 menisci from patients with severe gonarthritis. For the simultaneous examination of the articular cartilage and the menisci, we only tested the joint surfaces of the tibial plateau covered by the corresponding menisci. Over the posterior horn of the meniscus, the maximum applied load—the highest load registered by the load cell—of the arthritic samples of 0.02 ± 0.02 N was significantly greater (p = 0.04) than the maximum applied load of the arthritis-free samples of 0.01 ± 0.01 N. The instantaneous modulus (IM) at the center of the arthritic cartilage covered by the meniscus with 3.5 ± 2.02 MPa was significantly smaller than the IM of the arthritis-free samples with 5.17 ± 1.88 MPa (p = 0.04). No significant difference was found in the thickness of the meniscus-covered articular cartilage between the arthritic and arthritis-free samples. Significant correlations between the articular cartilage and the corresponding menisci were not observed at any point. In this study, the biomechanical changes associated with gonarthritis affected the posterior horn of the meniscus and the mid region of the meniscus-covered articular cartilage. The assessment of cartilage thickness as a structural characteristic of osteoarthritis may be misleading with regard to the interpretation of articular cartilage’s biomechanical properties.

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Outcomes More Than 2 Years After Meniscal Repair for Radial/Flap Tears of the Posterior Lateral Meniscus Combined With Anterior Cruciate Ligament Reconstruction

The American Journal of Sports Medicine ◽

10.1177/0363546519869955 ◽

2019 ◽

Vol 47 (12) ◽

pp. 2888-2894 ◽

Cited By ~ 1

Author(s):

Akira Tsujii ◽

Yasukazu Yonetani ◽

Kazutaka Kinugasa ◽

Tomohiko Matsuo ◽

Kenji Yoneda ◽

...

Keyword(s):

Tibial Plateau ◽

Cruciate Ligament ◽

Lateral Meniscus ◽

Posterior Horn ◽

Control Group ◽

Study Group ◽

Radiographic Outcomes ◽

Second Look ◽

Anterior Cruciate

Background: Meniscal function after repair of radial/flap tears of the posterior horn of the lateral meniscus (LM) with anterior cruciate ligament reconstruction (ACLR) has not been comprehensively investigated. Purpose: To evaluate not only the clinical and radiographic outcomes of patients with repair of radial/flap tears of the posterior LM with ACLR but also the healing status of the repaired meniscus and changes of chondral status with second-look arthroscopy. Study Design: Case series; Level of evidence, 4. Methods: From January 2008 to April 2016, 41 patients of a consecutive series of 505 primary anatomic ACLR cases had a concomitant radial/flap tear of the posterior horn of the LM and underwent side-to-side repair with an inside-out or all-inside technique. All patients were followed for >2 years, evaluated clinically and radiologically (radiograph and magnetic resonance imaging [MRI]), and compared with a control group without any concomitant injuries that underwent ACLR. Of the 41 patients, 30 were assessed by second-look arthroscopy 2 years postoperatively. Results: The mean follow-up times of the study and control groups were 3.4 and 3.9 years, respectively. The study group showed no significant differences in clinical findings, lateral joint space narrowing on radiograph, and coronal extrusion on MRI as compared with the control group, whereas sagittal extrusion on MRI progressed significantly in the study group (1.2 ± 1.5 mm vs 0.32 ± 1.0 mm, P < .001). Eighteen patients (60%) obtained complete healing; 9 (30%) showed partial healing; and 3 (10%) failed to heal on second-look arthroscopy. Changes of chondral status in the femoral condyle showed no significant difference between the groups ( P = .29). However, chondral status of the lateral tibial plateau worsened significantly in the study group ( P = .0011). Conclusion: The clinical and radiographic outcomes after repair of radial/flap tears of the posterior horn of the LM as combined with anatomic ACLR were successful and comparable with those after isolated ACLR without any other injuries at a mean postoperative follow-up of 3.4 years, except for sagittal extrusion on MRI. Chondral lesions of the lateral tibial plateau deteriorated regardless of meniscal healing at 2 years postoperatively. Surgeons should keep in mind that chondral injuries might progress over the midterm.

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Design of a Free-Floating Polycarbonate-Urethane Meniscal Implant Using Finite Element Modeling and Experimental Validation

Journal of Biomechanical Engineering ◽

10.1115/1.4001892 ◽

2010 ◽

Vol 132 (9) ◽

Cited By ~ 48

Author(s):

Jonathan J. Elsner ◽

Sigal Portnoy ◽

Gal Zur ◽

Farshid Guilak ◽

Avi Shterling ◽

...

Keyword(s):

Finite Element ◽

Pressure Distribution ◽

Implant Design ◽

Polycarbonate Urethane ◽

Joint Loads ◽

Contact Pressures ◽

Circumferential Reinforcement ◽

Cadaveric Knee

The development of a synthetic meniscal implant that does not require surgical attachment but still provides the biomechanical function necessary for joint preservation would have important advantages. We present a computational-experimental approach for the design optimization of a free-floating polycarbonate-urethane (PCU) meniscal implant. Validated 3D finite element (FE) models of the knee and PCU-based implant were analyzed under physiological loads. The model was validated by comparing calculated pressures, determined from FE analysis to tibial plateau contact pressures measured in a cadaveric knee in vitro. Several models of the implant, some including embedded reinforcement fibers, were tested. An optimal implant configuration was then selected based on the ability to restore pressure distribution in the knee, manufacturability, and long-term safety. The optimal implant design entailed a PCU meniscus embedded with circumferential reinforcement made of polyethylene fibers. This selected design can be manufactured in various sizes, without risking its integrity under joint loads. Importantly, it produces an optimal pressure distribution, similar in shape and values to that of natural meniscus. We have shown that a fiber-reinforced, free-floating PCU meniscal implant can redistribute joint loads in a similar pattern to natural meniscus, without risking the integrity of the implant materials.

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ACL Injury Mechanism is Related to Articular Pressure Distribution: A Cadaveric and Finite Element Investigation

ASME 2012 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2012-80659 ◽

2012 ◽

Author(s):

Ata M. Kiapour ◽

Constantine K. Demetropoulos ◽

Ali Kiapour ◽

Carmen E. Quatman ◽

Jason W. Levine ◽

...

Keyword(s):

Finite Element ◽

Pressure Distribution ◽

Tibial Plateau ◽

Cruciate Ligament ◽

Acl Injury ◽

High Rate ◽

Bone Bruise ◽

Acl Injuries ◽

Injury Mechanisms ◽

Anterior Cruciate

Acute anterior cruciate ligament (ACL) injury can be devastating, and often results in clinical sequelae that include meniscal tears, chondral lesions and osteoarthritis. Various bone bruise patterns of the femur or tibia, and bone contusions of the lateral tibial plateau have been associated in more than 80% of partial or complete ACL ruptures [1]. As quantification of articular cartilage pressure distribution under high-rate loading conditions remains challenging, validated finite element (FE) models of the knee can be used to characterize the effects of different loading parameters on tibiofemoral (TF) joint pressure distribution. This study combines high-rate cadaveric experiments with FE analysis to simulate ACL injuries and associated bone bruise patterns following landing from a jump. We hypothesized that a potential relationship exists between ACL injury mechanisms and resultant tibial plateau bone bruise patterns. This relationship may enhance our understanding of ACL injury mechanisms, which may provide insight to improve current prevention strategies that aim to decrease the risk of ACL injury and damage to secondary anatomical structures. All of this may in turn minimize associated posttraumatic knee osteoarthritis.

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Impact of posttraumatic steps on the intra-articular pressure of the lateral tibial plateau after fracture reconstruction: A biomechanical human cadaver study

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967117s00152 ◽

2017 ◽

Vol 5 (4_suppl4) ◽

pp. 2325967117S0015

Author(s):

Simon Oeckenpöhl ◽

Marcus Müller ◽

Dirk Wähnert ◽

Benedikt Schliemann ◽

Clemens Kösters

Keyword(s):

Pressure Distribution ◽

Tibial Plateau ◽

Soft Tissues ◽

Testing Machine ◽

Pressure Sensors ◽

Anatomical Reconstruction ◽

Lateral Tibial Plateau ◽

Anatomical Position ◽

Tibial Head ◽

Lateral Plateau

Aims and Objectives: The aim of reconstructing a tibial head fracture is the anatomical reconstruction. Which deviations from the anatomical position are tolerable and which misalignments could be treated conservatively, is currently not investigated. It is known that after tibial plateau fractures up to 7.3% of even treated patients develop a posttraumatic osteoarthritis requiring a prosthesis after 10 years. A rate of osteoarthritis after 5 1/2 years up to 40% is known after tibial head fractures. The aim of this study is to investigate the effects of the reduction on the intra-articular pressure distribution within the lateral tibial plateau in various degrees of flexion. Materials and Methods: In a human lateral tibial plateau fracture model (AO 41 B1, n = 8), the intra-articular pressure distribution was measured depending on misalignment after reposition (0-8 mm step in 1.0 mm steps) in various angles of flexion (0°, 15, 30°, 60°, 90°). Preserving the relevant ligamental structures, the soft tissues was removed and the knees wer embedded in PMMA cement (Technovit 3400, Heraeus). A standardized osteotomy, dividing the lateral articular surface in the middle of the primary-load zone has been performed. The lateral fragment was fixed by a self-constructed sled with an angular-stable plate (LCP TomoFix, Fa. Synthes) and moved in 1 mm steps from the anatomical position distal. The intra-articular pressure distribution was measured by pressure sensors (S2015 Double kneepad sensor, Fa. Novel) under axial compression on a servo-hydraulic testing machine (Instron 8874, Fa. Instron). Taking the mean of the averaged pressure distribution in the medial and lateral plateau, data was measured for 20 sec with a reading rate of 10 frames per second. Results: Increasing the misalignment-step, there is an increasing mean pressure in both plateaus in every angle of flexion. For example at 90° of flexion relative growth in pressure (means) in 1 mm increments steps: In the lateral plateau -5.6%; -2.1%; + 9.3%; + 11.8%; + 13.3%; + 15.9%; + 20.6%; + 23%. In the medial plateau, the pressure change is as follows: + 4.8%; + 8.0%; + 8.3%; + 8.8%; + 9.0%; + 9.3%; + 9.4%; + 9.5%. The data is similar in the other investigated degrees of flexion. The turning point of the pressure increase is lateral always at the 1-2 mm step. Conclusion: Small steps of only 2 mm lead to a significant increase in pressure - initially in the intact and later also in the fractured plateau. Referring to these findings, the indication for primary operative or conservative care and revision operations should be made. Intraoperative reposition should be performed as precise as possible - preferably controlled f.e. arthroscopically. The influence of the menisci on the pressure distribution is seen in the lateral plateau as it compensates the loss of area in smaller joint-steps. This mechanism will be content of further studies.

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