A Novel Quantitative Approach for Evaluating Contact Mechanics of Meniscal Replacements

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
E. Linder-Ganz ◽  
J. J. Elsner ◽  
A. Danino ◽  
F. Guilak ◽  
A. Shterling
Keyword(s):  
Contact Area ◽  
Peak Pressure ◽  
Contact Forces ◽  
Articular Surfaces ◽  
Joint Contact ◽  
Bench Testing ◽  
Contact Pressures ◽  
Implant Dislocation ◽  
Total Contact Area

One of the functions of the meniscus is to distribute contact forces over the articular surfaces by increasing the joint contact areas. It is widely accepted that total/partial loss of the meniscus increases the risk of joint degeneration. A short-term method for evaluating whether degenerative arthritis can be prevented or not would be to determine if the peak pressure and contact area coverage of the tibial plateau (TP) in the knee are restored at the time of implantation. Although several published studies already utilized TP contact pressure measurements as an indicator for biomechanical performance of allograft menisci, there is a paucity of a quantitative method for evaluation of these parameters in situ with a single effective parameter. In the present study, we developed such a method and used it to assess the load distribution ability of various meniscal implant configurations in human cadaveric knees (n=3). Contact pressures under the intact meniscus were measured under compression (1200 N, 0 deg flexion). Next, total meniscectomy was performed and the protocol was repeated with meniscal implants. Resultant pressure maps were evaluated for the peak pressure value, total contact area, and its distribution pattern, all with respect to the natural meniscus output. Two other measures—implant-dislocation and implant-impingement on the ligaments—were also considered. If any of these occurred, the score was zeroed. The total implant score was based on an adjusted calculation of the aforementioned measures, where the natural meniscus score was always 100. Laboratory experiments demonstrated a good correlation between qualitative and quantitative evaluations of the same pressure map outputs, especially in cases where there were contradicting indications between different parameters. Overall, the proposed approach provides a novel, validated method for quantitative assessment of the biomechanical performance of meniscal implants, which can be used in various applications ranging from bench testing of design (geometry and material of an implant) to correct implant sizing.

Meniscal Implant Biomechanical Performance: A Novel Quantitative Approach

2009 ◽  
Author(s):  
Jonathan J. Elsner ◽  
Eran Linder-Ganz ◽  
Amir Danino ◽  
Farshid Guilak ◽  
Avi Shterling
Keyword(s):  
Peak Pressure ◽  
Articular Surface ◽  
Contact Forces ◽  
Joint Degeneration ◽  
Partial Loss ◽  
Short Term ◽  
Degenerative Arthritis ◽  
Articular Surfaces ◽  
Joint Contact

One of the functions of the meniscus is to distribute contact forces over the articular surfaces by increasing joint contact areas [1]. It is widely accepted that total/partial loss of the meniscus increases the risk of joint degeneration. A short-term method for evaluating whether degenerative arthritis can be prevented would be to determine if peak pressure and contact area coverage of the tibialis plateau (TP) articular surface in the knee are restored at the time of implantation. Although several published studies already utilized TP contact pressure measurements as an indicator for biomechanical performance of allograft menisci [2,3], there is a paucity of a quantitative method for evaluation of these parameters in situ with a single effective parameter. In the present study, we developed such a method and employed it on sheep and human cadaveric knees.

scholarly journals Effect of Distal Tibial Varus and Valgus Deformity on Tibiotalar Joint Contact

2020 ◽  
Vol 5 (4) ◽  
pp. 2473011420S0025
Author(s):  
Zhao Hong-Mou
Keyword(s):  
Contact Pressure ◽  
Ankle Joint ◽  
Contact Area ◽  
Peak Pressure ◽  
Tibiotalar Joint ◽  
Force Center ◽  
Fibular Osteotomy ◽  
Group I ◽  
Joint Contact ◽  
Group A

Category: Ankle; Basic Sciences/Biologics Introduction/Purpose: To study the effect of different degrees of distal tibial varus and valgus deformities on the tibiotalar joint contact, and to understand the role of fibular osteotomy. Methods: Eight cadaveric lower legs were used for biomechanical study. Nine conditions were included: normal ankle joint (group A), 10° varus (group B), 5° varus (group C), 5° valgus (group D), 10° valgus (group E) with fibular preserved, and 10° varus (group F), 5° varus (group G), 5° valgus (group H), and 10° valgus (group I) after fibular osteotomy. The joint contact area, contact pressure, and peak pressure were tested; and the translation of contact force center was observed. Results: The joint contact area, contact pressure, and peak pressure had no significant difference between group A and groups B to E (P>0.05). After fibular osteotomy, the contact area decreased significantly in groups F and I when compared with group A (P<0.05); the contact pressure increased significantly in groups F, H, and I when compared with group A (P<0.05); the peak pressure increased significantly in groups F and I when compared with group A (P<0.05). There were two main anterior-lateral and anterior-medial contact centers in normal tibiotalar joint, respectively; and the force center was in anterior-lateral part, just near the center of tibiotalar joint. While the fibula was preserved, the force center transferred laterally with increased varus angles; and the force center transferred medially with increased valgus angles. However, the force center transferred oppositely to the medial part with increased varus angles, and laterally with increased valgus angles after fibular osteotomy. Conclusion: Fibular osteotomy facilitates the tibiotalar contact pressure translation, and is helpful for ankle joint realignment in suitable cases.

scholarly journals Ankle Joint Pressure in Supination-External Rotation Injuries: A Dynamic Biomechanic Cadaveric Study

2020 ◽  
Vol 5 (4) ◽  
pp. 2473011420S0030
Author(s):  
Fabian Krause ◽  
Ivan Zderic ◽  
Angela Seidel ◽  
Boyko Gueorguiev ◽  
Marc C. Attinger ◽  
...  
Keyword(s):  
Operative Treatment ◽  
Contact Area ◽  
Peak Pressure ◽  
External Rotation ◽  
Clinical Results ◽  
Deltoid Ligament ◽  
Type Ii ◽  
Type Iv ◽  
Joint Contact ◽  
Supination External Rotation

Category: Ankle; Basic Sciences/Biologics; Trauma Introduction/Purpose: In isolated lateral malleolar fractures of the supination-external rotation (SER) type and competent medial stabilizers (type II and III), non-operative treatment has yielded excellent outcome. With complete rupture of the deltoid ligament (SER type IV) fracture instability increases substantially. The rationale for operative treatment of SER type IV fractures is based upon good clinical results and previous biomechanical studies. A significant reduction of the ankle contact area that however is caused by an artificially forced lateralization of the talus in the ankle mortise has been demonstrated. Presumed resultant elevated joint contact stresses are thought to lead to ankle arthritis in the longterm. Methods: In 12 lower leg specimen SER type injuries were simulated by gradual bony and ligamentous destabilization of the ankle from lateral to medial according to the mechanism of injury as described by Lauge and Hansen. High-resolution pressure sensors placed in the ankle joint recorded tibio-talar pressure changes at physiologic weightbearing (700N) in three positions (plantigrade, 10° dorsiflexion and 20° plantarflexion). Results: With increasing instability changes of the ankle kinematics were seen in SER II and III fractures with the same trend also in SER IV lesions. In the plantigrade position, the medial clear space (MCS) increased significantly from an average of 2.5+-0.4mm (no fracture) to 3.9+-1.1mm (SER type IV fracture). However, the corresponding peak pressure increased only slightly from 2.6+- 0.5 mPa to 3.0+-1.4 mPa on average, and the contact area decreased slightly from 810+-42 mm2 to 735+-27mm2 on average representing a non-significant reduction of only 9% of the contact area (p=0.08) after the deep deltoid ligament was completely dissected.The comparison of the results in plantigrade and plantarflexed position revealed substantial differences for MCS, contact area and center of force. Conclusion: Under physiologic load SER type IV isolated lateral malleolar fracture with completely disrupted deep deltoid ligament led to a significant increase of the MCS, but neither to a significant decrease of the of the joint contact area nor significant increase of peak pressure. Clinical Relevance: The findings of this biomechanical study support the recently reported good clinical results of non-operative treatment of SER type II to IV fractures.

EXPERIMENTAL DETERMINATION OF IN VIVO PRESSURE DISTRIBUTION IN BIOLOGIC JOINTS

2000 ◽  
Vol 04 (01) ◽  
pp. 1-7 ◽  
Author(s):  
W. Herzog ◽  
E. M. Hasler ◽  
T. R. Leonard
Keyword(s):  
Muscle Force ◽  
Experimental Approach ◽  
Pressure Distributions ◽  
Joint Contact ◽  
Hindlimb Movement ◽  
Joint Contact Pressure ◽  
Contact Pressures

The purpose of this communication is to present an idea, and its technical implementation, on how to estimate experimentally in vivo joint contact pressure distributions. The idea is illustrated for the cat patellofemoral joint. For this particular joint, the approach requires muscle force and hindlimb movement measurements during unrestrained locomotion, and the quantification of the joint contact pressures in situ for conditions approximating the in vivo conditions as closely as possible. Although the approach is time-consuming and has its limitations, it is, as far as we know, the first purely experimental approach to determine the in vivo joint contact pressures during normal movement. "Purely experimental" refers to the idea that the required movements, muscle forces and contact pressures are all measured rather than estimated theoretically.

Radiocarpal Contact Pressures Are Not Altered after Scapholunate Ligament Tears

2021 ◽  
Author(s):  
Hailey P. Huddleston ◽  
Joey S. Kurtzman ◽  
Kenneth H. Levy ◽  
Katherine M. Connors ◽  
Westley T. Hayes ◽  
...  
Keyword(s):  
Contact Pressure ◽  
Contact Area ◽  
Axial Load ◽  
Peak Pressure ◽  
Scapholunate Ligament ◽  
Interosseous Ligament ◽  
Radiocarpal Joint ◽  
Peak Pressures ◽  
Contact Pressures ◽  
Lunate Fossa

Abstract Background The scapholunate interosseous ligament (SLIL) couples the scaphoid and lunate, preventing motion and instability. Prior studies suggest that damage to the SLIL may significantly alter contact pressures of the radiocarpal joint. Questions/Purposes The purpose of this study was to investigate the contact pressure and contact area in the scaphoid and lunate fossae of the radius prior to and after sectioning the SLIL. Methods Ten cadaveric forearms were dissected distal to 1-cm proximal to the radiocarpal joint and a Tekscan sensor was placed in the radiocarpal joint. The potted specimen was mounted and an axial load of 200 N was applied over 60 seconds. Results Sectioning of the SLIL did neither significantly alter mean contact pressure at the lunate fossa (p = 0.842) nor scaphoid fossa (p = 0.760). Peak pressures were similar between both states at the lunate and scaphoid fossae (p = 0.301–0.959). Contact areas were similar at the lunate fossa (p = 0.508) but trended toward an increase in the SLIL sectioned state in the scaphoid fossa (p = 0.055). No significant differences in the distribution of contact pressure (p = 0.799), peak pressure (p = 0.445), and contact area (p = 0.203) between the scaphoid and lunate fossae after sectioning were observed. Conclusion Complete sectioning of the SLIL in isolation may not be sufficient to alter the contact pressures of the wrist. Clinical Relevance Injury to the secondary stabilizers of the SL joint, in addition to complete sectioning of the SLIL, may be needed to induce altered biomechanics and ultimately degenerative changes of the radiocarpal joint.

scholarly journals The Effect of Achilles Tendon Loading on Ankle Joint Contact Area and Peak Pressure

2018 ◽  
Vol 3 (3) ◽  
pp. 2473011418S0030
Author(s):  
L. Daniel Latt ◽  
Alfonso Ayala ◽  
Samuel Kim ◽  
Jesus Lopez
Keyword(s):  
Achilles Tendon ◽  
Ankle Joint ◽  
Contact Area ◽  
Axial Load ◽  
Peak Pressure ◽  
The Body ◽  
Neutral Position ◽  
Joint Contact ◽  
Axially Loaded ◽  
The Impact

Category: Ankle Introduction/Purpose: Increased tibiotalar peak pressure (PP) and decreased contact area (CA) following ankle fracture are associated with the development of post-traumatic osteoarthtritis. Lateral talar translation of just 1 mm has been shown to decrease CA by 42%. The impact of talar malalignment in other directions on ankle joint contact pressures (AJCP) are not well understood. The majority of research on AJCP has utilized cadaveric models in which body weight is simulated with an axial load applied through the tibia. This model does not account for Achilles tendon - which transmits the largest tendon force in the body during weight bearing. This study aimed to determine the effects of Achilles tendon loading on tibiotalar CA and PP in an axially loaded cadaver model at different ankle flexion angles. Methods: Ten fresh frozen cadaveric lower extremity specimens transected mid-tibia were dissected free of soft tissues surrounding the ankle, sparing the ligaments. The proximal tibia and fibula were potted in quick drying cement for rigid mounting on a MTS machine. A pressure sensing element (TekScan KScan model 5033) was inserted into the tibiotalar joint and used to measure CA (cm2) and PP (MPa). An axial load of 686 N was applied through the tibia and fibula, followed by a 350 N load via the Achilles tendon to simulate mid-stance conditions. Measurements were taken at neutral position, 15 degrees of dorsiflexion and 15 degrees of plantarflexion, with and without Achilles load. The effects of Achilles load and ankle flexion angle on CA and PP were analyzed using a 2x3 ANOVA. Bonferroni post-hoc adjustments were used for multiple comparisons. Level of statistical significance was set at p < 0.05. Results: ANOVA revealed significant main effects of ankle flexion on contact area and peak pressures (Table 1). Contact area was significantly lower for 15 degrees of plantarflexion than neutral and 15 degrees of dorsiflexion (p < 0.001). In addition, peak pressure was significantly higher for 15 degrees of plantarflexion than neutral and 15 degrees of dorsiflexion. ANOVA also indicated that contact area and peak pressure were significantly higher with Achilles load than without (p < 0.001). No interaction effects were found. Conclusion: The applied Achilles tendon load significantly altered tibiotalar PP in an axially loaded cadaver model. On the other hand, changes in CA with Achilles load were found to be minimal (~1.8%). We also found that the greatest PP and smallest CA occured during plantar flexion. This observation can be explained by a difference in width between the anterior and posterior talus. While the results of this study demonstrate the importance of Achilles tendon load on tibiotalar measurements, further studies investigating the effects of additional factors such as loading techniques are warranted to improve the physiological accuracy of cadaver models.

Trochlear Contact Pressures after Straight Anteriorization of the Tibial Tuberosity

2008 ◽  
Vol 36 (10) ◽  
pp. 1953-1959 ◽  
Author(s):  
John-Paul H. Rue ◽  
Anne Colton ◽  
Stephanie M. Zare ◽  
Elizabeth Shewman ◽  
Jack Farr ◽  
...  
Keyword(s):  
Contact Area ◽  
Clinical Relevance ◽  
Knee Flexion ◽  
Patellofemoral Joint ◽  
Pressure Sensors ◽  
Contact Forces ◽  
Tibial Tuberosity ◽  
Before And After ◽  
The Mean ◽  
Contact Pressures

Background Anteromedialization of the tibial tuberosity has been shown to decrease mean total contact pressures of the lateral trochlea and to shift contact pressures to the medial trochlea. Hypothesis Modifying the anteromedialization osteotomy to a straight anteriorization osteotomy of the tibial tuberosity can decrease trochlear contact pressures without a resultant medial shift of forces to the medial trochlear contact area. Study Design Controlled laboratory study. Methods Ten cadavers were tested before and after straight anteriorization tibial tuberosity osteotomy by loading the extensor mechanism with 89.1 and 178.2 N at 0°, 30°, 60°, and 90° of flexion following a validated patellofemoral joint loading protocol. Contact pressures were measured with electroresistive pressure sensors placed directly on the trochlea. Results The mean trochlear contact pressures after osteotomy decreased significantly ( P < .05) for loads of 89.1 and 178.2 N at both 30° (23% and 20%, respectively) and 60° (18.7% and 31.9%, respectively) of knee flexion. The peak contact pressures decreased significantly ( P < .05) for loads of 89.1 and 178.2 N at 30° (24.3% and 27.0%, respectively) and 60° (31.9% and 24.5%, respectively) and for loads of 89.1 N at 90° (13.4%) of knee flexion. Conclusion The authors demonstrated significantly decreased trochlear contact forces after straight anteriorization osteotomy of the tibial tuberosity, without a significant resultant medial shift of the center of force. Clinical Relevance Straight anteriorization of the tibial tuberosity may be a useful adjunct for patients with medial articular defects of the patellar or trochlea in whom anteromedialization would be otherwise contraindicated.

Elevated Joint Contact Forces in ACL-Reconstructed Knees: A Finite Element Analysis Driven by In Vivo Kinematic Data

2003 ◽  
Author(s):  
George Papaioannou ◽  
William Anderst ◽  
Scott Tashman
Keyword(s):  
Finite Element ◽  
High Speed ◽  
Knee Kinematics ◽  
Poor Quality ◽  
Contact Forces ◽  
Element Analysis ◽  
Human Cartilage ◽  
Joint Contact ◽  
Contact Pressures

Assessment of in vivo human cartilage loading generally requires computer modeling, since loads usually cannot be directly measured. The utility of these models for assessing knee behavior during complex activities has been limited by the relatively poor quality of experimental data on in vivo knee function. We have developed a method combining high-accuracy knee kinematics (from high-speed stereo-radiography) with subject-specific finite-element models to estimate in vivo cartilage contact pressures during stressful tasks. When applied to ACL reconstruction, significantly higher contact pressures were found in reconstructed knees as compared to the contralateral (uninjured) knees of the same individuals.

Tibiofemoral Joint Contact Force in Deep Knee Flexion and Its Consideration in Knee Osteoarthritis and Joint Replacement

2006 ◽  
Vol 22 (4) ◽  
pp. 305-313 ◽  
Author(s):  
Takeo Nagura ◽  
Hideo Matsumoto ◽  
Yoshimori Kiriyama ◽  
Ajit Chaudhari ◽  
Thomas P. Andriacchi
Keyword(s):  
Contact Stress ◽  
Contact Area ◽  
Knee Prosthesis ◽  
Contact Forces ◽  
Normal Contact ◽  
Tibiofemoral Joint ◽  
Deep Flexion ◽  
Joint Force ◽  
Joint Contact ◽  
Stress Simulation

The aim of the study was to estimate the tibiofemoral joint force in deep flexion to consider how the mechanical load affects the knee. We hypothesize that the joint force should not become sufficiently large to damage the joint under normal contact area, but should become deleterious to the joint under the limited contact area. Sixteen healthy knees were analyzed using a motion capture system, a force plate, a surface electromyography, and a knee model, and then tibiofemoral joint contact forces were calculated. Also, a contact stress simulation using the contact areas from the literature was performed. The peak joint contact forces (M±SD) were 4566 ± 1932 N at 140 degrees in rising from full squat and 4479 ± 1478 N at 90 degrees in rising from kneeling. Under normal contact area, the tibiofemoral contact stresses in deep flexion were less than 5 MPa and did not exceed the stress to damage the cartilage. The contact stress simulation suggests that knee prosthesis having the contact area smaller than 200 mm2may be problematic since the contact stress in deep flexion would become larger than 21 MPa, and it would lead damage or wear of the polyethylene.

scholarly journals The Effects of Fibular Malrotation on Tibiotalar Contact Area and Peak Pressure Distributions in Weber B Ankle Fractures

2020 ◽  
Vol 5 (4) ◽  
pp. 2473011420S0028
Author(s):  
Ansab M. Khwaja ◽  
Alfonso E. Ayala ◽  
Brianna Goodison ◽  
Jared Irwin ◽  
L. Daniel Latt
Keyword(s):  
Contact Area ◽  
Soft Tissues ◽  
Peak Pressure ◽  
Ankle Fractures ◽  
Sensing Element ◽  
Tibiotalar Joint ◽  
Pressure Distributions ◽  
Joint Contact ◽  
Fresh Frozen ◽  
Fixed State

Category: Basic Sciences/Biologics; Ankle; Hindfoot; Trauma Introduction/Purpose: Decreased tibiotalar joint contact area (CA) and increased peak pressure (PP) following rotational ankle fractures may predispose the development of post-traumatic osteoarthritis. Previous studies have highlighted the effects of lateral talar translation on tibiotalar joint congruity. However, debate remains regarding surgical indications in minimally displaced (< 2mm of clear space widening), but potentially malrotated ankle fractures. Malrotation of the talus and fibula are poorly visualized on plain radiographs, thus their impact on ankle joint contact mechanics has not been determined. The aim of this project is to understand the effects of fibular malrotation on tibiotalar joint CA and PP distributions using an axially loaded cadaveric model. We hypothesized that fibular malrotation would result in decreased contact area and increased peak pressures within the tibiotalar joint. Methods: Ten fresh frozen cadaveric lower extremity specimens transected mid-tibia were dissected free of soft tissues surrounding the ankle, sparing the ligaments. The proximal tibia and fibula were potted in quick drying cement for rigid mounting on a MTS machine. A pressure sensing element (TekScan model 5033) was inserted into the tibiotalar joint and used to measure CA (cm2) and PP (MPa). An axial load of 686 N was applied through the tibia and fibula, followed by a 147 N load via the Achillies tendon at mid-stance position, 15o dorsiflexion and 15o plantarflexion. The samples were first tested in the native condition, a Weber B ankle fracture was simulated and then re-tested in an anatomically fixed state, and a malrotated state. Malrotation was achieved by externally rotating the talus and shortening the fibula along the fracture by the maximal amount that would allow bony apposition along the fracture line (usually 5-10mm). Results: In the six ankles tested thus far (Figure 1), we have observed small but statistically insignificant (P>0.05) increases in tibiotalar CA at all stance phases following malreduction. Significant (p>0.05) increases in tibiotalar PP were seen mid-stance following a simulated Weber B fracture, and these changes were shown to be greatest in the malreduced state versus the anatomically fixed state (7.21 MPa vs. 6.35 MPa respectively, p = 0.004). Interestingly, similar (p=0.84) decreases tibiotalar PP were shown during plantarflexion following a simulated Weber B fracture fixed in both the anatomically fixed and malreduced state. Conclusion: Our preliminary data supports the notion that significant changes in tibiotalar PP occur following ankle fractures even in an anatomically fixed state. Increases in tibiotalar PP seem to be further amplified following malreduction at specific stance phases. Further data collection is needed to validate these findings, and to determine the role of malrotation as a potential surgical indication for minimally laterally displaced ankle fractures.

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