Effects of Proud Large Osteochondral Plugs on Contact Forces and Knee Kinematics: A Robotic Study

2018 ◽  
Vol 46 (9) ◽  
pp. 2122-2127 ◽  
Author(s):  
Peter Z. Du ◽  
Keith L. Markolf ◽  
Daniel V. Boguszewski ◽  
Kent T. Yamaguchi ◽  
Christopher J. Lama ◽  
...  
Keyword(s):  
Lateral Meniscus ◽  
Knee Kinematics ◽  
Contact Forces ◽  
Osteochondral Allograft ◽  
Cartilage Defects ◽  
Tibial Rotation ◽  
Native Bone ◽  
Rotational Kinematics ◽  
Internal Tibial Rotation ◽  
Articular Cartilage Defects

Background: Osteochondral allograft (OCA) transplantation is used to treat large focal femoral condylar articular cartilage defects. A proud plug could affect graft survival by altering contact forces (CFs) and knee kinematics. Hypothesis: A proud OCA plug will significantly increase CF and significantly alter knee kinematics throughout controlled knee flexion. Study Design: Controlled laboratory study. Methods: Human cadaver knees had miniature load cells, each with a 20-mm-diameter cylinder of native bone/cartilage attached at its exact anatomic position, installed in both femoral condyles at standardized locations representative of clinical defects. Spacers were inserted to create proud plug conditions of +0.5, +1.0, and +1.5 mm. CFs and knee kinematics were recorded as a robot flexed the knee continuously from 0° to 50° under 1000 N of tibiofemoral compression. Results: CFs were increased significantly (vs flush) for all proudness conditions between 0° and 45° of flexion (medial) and 0° to 50° of flexion (lateral). At 20°, the average increases in medial CF for +0.5-mm, +1-mm, and +1.5-mm proudness were +80 N (+36%), +155 N (+70%), and +193 N (+87%), respectively. Corresponding increases with proud lateral plugs were +44 N (+14%), +90 N (+29%), and +118 N (+38%). CF increases for medial plugs at 20° of flexion were significantly greater than those for lateral plugs at all proudness conditions. At 50°, a 1-mm proud lateral plug significantly decreased internal tibial rotation by 15.4° and decreased valgus rotation by 2.5°. Conclusion: A proud medial or lateral plug significantly increased CF between 0° and 45° of flexion. Our results suggest that a medial plug at 20° may be more sensitive to graft incongruity than a lateral plug. The changes in rotational kinematics with proud lateral plugs were attributed to earlier contact between the proud plug’s surface and the lateral meniscus, leading to rim impingement with decreased tibial rotation. Clinical Relevance: Increased CF and altered knee kinematics from a proud femoral plug could affect graft viability. Plug proudness of only 0.5 mm produced significant changes in CF and knee kinematics, and the clinically accepted 1-mm tolerance may need to be reexamined in view of our findings.

Muscle and Contact Contributions to Inverse Dynamic Knee Loads During Gait

2009 ◽  
Author(s):  
Benjamin J. Fregly ◽  
Yi-Chung Lin ◽  
Jonathan P. Walter ◽  
Marcus G. Pandy ◽  
Scott A. Banks ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Degrees Of Freedom ◽  
Muscle Force ◽  
Human Movement ◽  
Contact Forces ◽  
Cartilage Defects ◽  
Inverse Dynamic ◽  
Joint Replacements ◽  
Joint Contact ◽  
Articular Cartilage Defects

Musculoskeletal computer models capable of predicting muscle and joint contact forces accurately during human movement could facilitate the design of improved joint replacements and new clinical treatments for articular cartilage defects or movement-related disorders [1]. A primary challenge to developing such predictions is the non-uniqueness of the calculated muscle forces, often referred to as the “muscle redundancy problem” [2]. Since more muscles act on the skeleton than the number of degrees of freedom in the skeleton, an infinite number of possible muscle force solutions exist.

Effect of Slope and Varus Correction High Tibial Osteotomy in the ACL-Deficient and ACL-Reconstructed Knee on Kinematics and ACL Graft Force: A Biomechanical Analysis

2020 ◽  
pp. 036354652097614
Author(s):  
Florian B. Imhoff ◽  
Brendan Comer ◽  
Elifho Obopilwe ◽  
Knut Beitzel ◽  
Robert A. Arciero ◽  
...  
Keyword(s):  
High Tibial Osteotomy ◽  
Knee Kinematics ◽  
Tibial Rotation ◽  
Tibial Osteotomy ◽  
Correction Osteotomy ◽  
Acl Graft ◽  
Slope Correction ◽  
Internal Tibial Rotation ◽  
Reconstructed Knee ◽  
Acl Deficient

Background: Correction of high posterior tibial slope is an important treatment option for revision of anterior cruciate ligament (ACL) failure as seen in clinical and biomechanical studies. In cases with moderate to severe medial compartment arthritis, an additional varus correction osteotomy may be added to improve alignment. Purpose: To investigate the influence of coronal and sagittal correction high tibial osteotomy in ACL-deficient and ACL-reconstructed knees on knee kinematics and ACL graft load. Study Design: Controlled laboratory study. Methods: Ten cadaveric knees were selected according to previous computed tomography measurements with increased native slope and slight varus tibial alignment (mean ± SD): slope, 9.9°± 1.4°; medial proximal tibia angle, 86.5°± 2.1°; age, 47.7 ± 5.8 years. A 10° anterior closing-wedge osteotomy, as well as an additional 5° of simulated varus correction osteotomy, were created and fixed using an external fixator. Four alignment conditions—native, varus correction, slope correction, and combined varus and slope correction—were randomly tested in 2 states: ACL-deficient and ACL-reconstructed. Compressive axial loads were applied to the tibia while mounted on a free-moving X-Y table and free-rotating tibia in a knee testing fixture. Three-dimensional motion tracking captured anterior tibial translation (ATT) and internal tibial rotation. Change of tensile forces on the reconstructed ACL graft were recorded. Results: In the ACL-deficient knee, an isolated varus correction led to a significant increase of ATT by 4.3 ± 4.0 mm ( P = .04). Isolated slope reduction resulted in the greatest decrease of ATT by 6.2 ± 4.3 mm ( P < .001). In the ACL-reconstructed knee, ATT showed comparable changes, while combined varus and slope correction led to lower ATT by 3.7 ± 2.6 mm ( P = .01) than ATT in the native alignment. Internal tibial rotation was not significantly altered by varus correction but significantly increased after isolated slope correction by 4.0°± 4.1° ( P < .01). Each isolated or combined osteotomy showed decreased forces on the graft as compared with the native state. The combined varus and slope osteotomy led to a mean decrease of ACL graft force by 33% at 200 N and by 58% at 400 N as compared with the native condition ( P < .001). Conclusion: A combined varus and slope correction led to a relevant decrease of ATT in the ACL-deficient and ACL-reconstructed cadaveric knee. ACL graft forces were significantly decreased after combined varus and slope correction. Thus, our biomechanical findings support the treatment goal of a perpendicular-aligned tibial plateau for ACL insufficiencies, especially in cases of revision surgery. Clinical Relevance: This study shows the beneficial knee kinematics and reduced forces on the ACL graft after combined varus and slope correction.

Contact Forces Acting on Large Femoral Osteochondral Allografts During Forced Knee Extension

2017 ◽  
Vol 45 (12) ◽  
pp. 2804-2811 ◽  
Author(s):  
Peter Z. Du ◽  
Keith L. Markolf ◽  
Christopher J. Lama ◽  
David R. McAllister ◽  
Kristofer J. Jones
Keyword(s):  
Clinical Relevance ◽  
Knee Extension ◽  
Load Cell ◽  
Contact Forces ◽  
Osteochondral Allograft ◽  
Human Knee ◽  
Native Bone ◽  
Load Cells ◽  
The Mean ◽  
Femoral Condyles

Background: A single cylindrical graft plug is commonly used for large focal femoral defects during osteochondral allograft (OCA) transplantation. Excessive contact force (CF) on a proud plug could compromise initial healing. CFs during forced knee extension are of particular interest because this maneuver is used by therapists to restore early postoperative range of motion. Hypothesis: A proud OCA plug will significantly increase the CF and significantly decrease the knee extension angle (KEA). Study Design: Controlled laboratory study. Methods: Eleven human knee specimens had miniature load cells installed in both femoral condyles at standardized locations representative of clinical defects. Each load cell had a 20-mm–diameter cylinder of native bone/cartilage attached at its precise anatomic location. Four spacers, 0.5 mm in thickness, were inserted sequentially between each load cell and its mounting bracket to create proud plug conditions of 0.5 to 2 mm. Measurements of the CF and KEA were recorded at extension moment levels up to 8 N·m. Results: At 8 N·m, the mean CFs for flush plugs were 149 ± 18 N (lateral) and 34 ± 13 N (medial). The mean increases in the medial CF (compared with flush) for 0.5-mm, 1-mm, 1.5-mm, and 2-mm proud conditions were 31 N (+91%), 64 N (+188%), 111 N (+325%), and 154 N (+451%), respectively. Corresponding increases for lateral proud plugs were 55 N (+37%), 120 N (+81%), 162 N (+109%), and 210 N (+141%), respectively. The CFs (and CF increases) for lateral grafts were significantly ( P < .05) higher than corresponding values for medial grafts at each proudness condition. Medial plug proudness had no consistent effect on the KEA. A 1-mm proud lateral plug significantly reduced the KEA by −1.6° (0 N·m) and −0.9° (2 N·m). Conclusion: Graft proudness of only 0.5 mm significantly increased CFs during forced knee extension, emphasizing the surgical precision necessary to achieve normal CF levels. Clinical Relevance: It is believed that some amount of CF is beneficial in the early stages of graft healing, and our findings suggest that forced knee extension may be well suited for this purpose. However, the surgeon should be aware that large extension moments can also generate relatively high CFs, especially if the plug is proud.

scholarly journals Current solutions for the treatment of chronic articular cartilage defects in the knee

2020 ◽  
Vol 5 (3) ◽  
pp. 156-163 ◽  
Author(s):  
Mukai Chimutengwende-Gordon ◽  
James Donaldson ◽  
George Bentley
Keyword(s):  
Donor Site ◽  
Donor Site Morbidity ◽  
Degenerative Joint Disease ◽  
Joint Disease ◽  
Osteochondral Allograft ◽  
Cartilage Defects ◽  
Rehabilitation Period ◽  
Chondrocyte Implantation ◽  
Osteochondral Autograft Transfer ◽  
Articular Cartilage Defects

Chondral and osteochondral defects in the knee are common and may lead to degenerative joint disease if treated inappropriately. Conventional treatments such as microfracture often result in fibrocartilage formation and are associated with inferior results. Additionally, microfracture is generally unsuitable for the treatment of defects larger than 2–4 cm2. The osteochondral autograft transfer system (OATS) has been shown to produce superior clinical outcomes to microfracture but is technically difficult and may be associated with donor-site morbidity. Osteochondral allograft use is limited by graft availability and failure of cartilage incorporation is an issue. Autologous chondrocyte implantation (ACI) has been shown to result in repair with hyaline-like cartilage but involves a two-stage procedure and is relatively expensive. Rehabilitation after ACI takes 12 months, which is inconvenient and not feasible for athletic patients. Newer methods to regenerate cartilage include autologous stem cell transplantation, which may be performed as a single-stage procedure, can have a shorter rehabilitation period and is less expensive than ACI. Longer-term studies of these methods are needed. Cite this article: EFORT Open Rev 2020;5:156-163. DOI: 10.1302/2058-5241.5.190031

scholarly journals Small Lateral Meniscus Tears Propagate and are Detrimental to Knee Kinematics and Contact Forces

2019 ◽  
Vol 7 (6_suppl4) ◽  
pp. 2325967119S0023
Author(s):  
Joao Novaretti ◽  
Elmar Herbst ◽  
Calvin Chan ◽  
Richard Debski ◽  
Volker Musahl
Keyword(s):  
Lateral Meniscus ◽  
Knee Kinematics ◽  
Contact Forces ◽  
Posterior Horn ◽  
Meniscus Tear ◽  
Tibiofemoral Joint ◽  
Meniscus Tears ◽  
Tear Propagation ◽  
Resultant Forces ◽  
Acl Deficient

Aims and Objectives: To quantify propagation of small vertical lateral meniscus tears located in the posterior horn during simulated cyclic cutting maneuvers on a robotic testing system and the resulting changes in knee kinematics and forces. Materials and Methods: 14 fresh-frozen human cadaveric knees (mean age: 74.8 ± 14.4) were mounted onto a 6-DOF robotic testing system. Knees with osteoarthritis greater than grade II were excluded. A small vertical tear in the posterior horn of the lateral meniscus medial to the popliteus tendon was created via a posterior arthrotomy. Tear length was measured with a custom-made device (accuracy 0.2 mm, inter-rater reliability 0.914). In 6 specimens, the ACL was resected arthroscopically, whereas in 8 knees the ACL was left intact. 10Nm valgus and 5Nm external rotation moment combined with 250N of axial compression were applied while the knees were continuously flexed from full extension to 90° of flexion for 500 cycles. Meniscus tear length was measured after each 100 cycles. After the measurements, the posterior capsule and skin were closed in a standardized fashion. Knee kinematics, the in situ force in the ACL, the resultant force in the lateral meniscus, and bony contact forces at the tibiofemoral joint were calculated at 30°, 60°, and 90° of knee flexion. A repeated measures ANOVA was used to compared the outcome parameters between knee states (p < 0.05). Results: In intact knees, small vertical lateral meniscus tears propagated significantly from baseline to 100, 200, 300, 400, and 500 cycles (all p < 0.001). This corresponds to a tear propagation of 28.7% ± 5.4%. Similarly, in ACL deficient knees meniscus tear propagation was significant throughout all sets of cycles (p = 0.001). This corresponds to a tear propagation of 26.1% ± 8.3%. While in intact knees, external tibial rotation was significantly increased by up to 45.5% after meniscus tear propagation, knee kinematics were not significantly affected in ACL deficient knees (NS). The resultant forces in the lateral meniscus increased with tear propagation in the intact knees by up to 54.1%. Likewise, the resultant forces in the lateral meniscus increased in the ACL deficient knees by up to 116.5% (p < 0.05). In intact knees, bony contact forces at the tibiofemoral joint increased with meniscus tear propagation by up to 91.9% (p < 0.05), which was comparable to ACL deficient knees. Conclusion: The data of this study suggest, that small vertical lateral meniscus tears propagate significantly regardless of the integrity of the ACL and after only 100 cycles of knee loading. The findings of the current robotic study are in contrast to recent clinical studies that found that small, vertical and stable tears in the posterior horn of the lateral meniscus could be left in situ. However, based on the current data, such tears do propagate over time regardless of the integrity of the ACL, which might alter knee kinematics and resultant forces in the lateral meniscus as well as bony contact forces at the tibiofemoral joint.

scholarly journals An insert with less than spherical medial conformity causes a loss of passive internal rotation after calipered kinematically aligned TKA

2021 ◽  
Author(s):  
Alexander J. Nedopil ◽  
Adithya Shekhar ◽  
Stephen M. Howell ◽  
Maury L. Hull
Keyword(s):  
Internal Rotation ◽  
Flat Surface ◽  
Cruciate Ligament ◽  
Knee Kinematics ◽  
Kinematic Alignment ◽  
Tibial Rotation ◽  
Mean Values ◽  
Healthy Knee ◽  
Internal Tibial Rotation ◽  
Lift Off

Abstract Introduction In total knee arthroplasty (TKA), the level of conformity, a medial stabilized (MS) implant, needs to restore native (i.e., healthy) knee kinematics without over-tensioning the flexion space when the surgeon chooses to retain the posterior cruciate ligament (PCL) is unknown. Whether an insert with a medial ball-in-socket conformity and lateral flat surface like the native knee or a less than spherical medial conformity restores higher and closer to native internal tibial rotation without anterior lift-off, an over-tension indicator, when implanted with calipered kinematic alignment (KA), is unknown. Methods and materials Two surgeons treated 21 patients with calipered KA and a PCL retaining MS implant. Validated verification checks that restore native tibial compartment forces in passive flexion without release of healthy ligaments were used to select the optimal insert thickness. A goniometer etched onto trial inserts with the ball-in-socket and the less than spherical medial conformity measured the tibial rotation relative to the femoral component at extension and 90° and 120° flexion. The surgeon recorded the incidence of anterior lift-off of the insert. Results The insert with the medial ball-in-socket and lateral flat surface restored more internal tibial rotation than the one with less than spherical medial conformity, with mean values of 19° vs. 17° from extension to 90° flexion (p < 0.01), and 23° vs. 20°–120° flexion (p < 0.002), respectively. There was no anterior lift-off of the insert at 90° and 120° flexion. Conclusion An MS insert with a medial ball-in-socket and lateral flat surface that matches the native knee’s spherical conformity restores native tibial internal rotation when implanted with calipered KA and PCL retention without over-tensioning the flexion space.

scholarly journals Engineering large, anatomically shaped osteochondral constructs with robust interfacial shear properties

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Wendy E. Brown ◽  
Brian J. Huang ◽  
Jerry C. Hu ◽  
Kyriacos A. Athanasiou
Keyword(s):  
Mechanical Properties ◽  
Interfacial Shear Strength ◽  
Femoral Condyle ◽  
Interfacial Shear ◽  
Cartilage Defects ◽  
Porous Hydroxyapatite ◽  
Cartilage Lesions ◽  
Large Cartilage Lesions ◽  
Articular Cartilage Defects ◽  
Shape And Size

AbstractDespite the prevalence of large (>5 cm2) articular cartilage defects involving underlying bone, current tissue-engineered therapies only address small defects. Tissue-engineered, anatomically shaped, native-like implants may address the need for off-the-shelf, tissue-repairing therapies for large cartilage lesions. This study fabricated an osteochondral construct of translationally relevant geometry with robust functional properties. Scaffold-free, self-assembled neocartilage served as the chondral phase, and porous hydroxyapatite served as the osseous phase of the osteochondral constructs. Constructs in the shape and size of an ovine femoral condyle (31 × 14 mm) were assembled at day 4 (early) or day 10 (late) of neocartilage maturation. Early osteochondral assembly increased the interfacial interdigitation depth by 244%, interdigitation frequency by 438%, interfacial shear modulus by 243-fold, and ultimate interfacial shear strength by 4.9-fold, compared to late assembly. Toward the development of a bioprosthesis for the repair of cartilage lesions encompassing up to an entire condylar surface, this study generated a large, anatomically shaped osteochondral construct with robust interfacial mechanical properties and native-like neocartilage interdigitation.

Sign in / Sign up

Export Citation Format

Share Document