Autologous Osteochondral Transplantation of the Talus Partially Restores Contact Mechanics of the Ankle Joint

2011 ◽  
Vol 39 (11) ◽  
pp. 2457-2465 ◽  
Author(s):  
Ashraf M. Fansa ◽  
Christopher D. Murawski ◽  
Carl W. Imhauser ◽  
Joseph T. Nguyen ◽  
John G. Kennedy
Keyword(s):  
Contact Mechanics ◽  
Ankle Joint ◽  
Osteochondral Defect ◽  
Peak Pressure ◽  
Osteochondral Graft ◽  
Osteochondral Transplantation ◽  
Talar Dome ◽  
Autologous Osteochondral Transplantation ◽  
Medial Region ◽  
Mean Pressure

Background: Autologous osteochondral transplantation procedures provide hyaline cartilage to the site of cartilage repair. It remains unknown whether these procedures restore native contact mechanics of the ankle joint. Purpose: This study was undertaken to characterize the regional and local contact mechanics after autologous osteochondral transplantation of the talus. Study Design: Controlled laboratory study. Methods: Ten fresh-frozen cadaveric lower limb specimens were used for this study. Specimens were loaded using a 6 degrees of freedom robotic arm with 4.5 N·m of inversion and a 300-N axial compressive load in a neutral plantar/dorsiflexion. An osteochondral defect was created at the centromedial aspect of the talar dome and an autologous osteochondral graft from the ipsilateral knee was subsequently transplanted to the defect site. Regional contact mechanics were analyzed across the talar dome as a function of the defect and repair conditions and compared with those in the intact ankle. Local contact mechanics at the peripheral rim of the defect and at the graft site were also analyzed and compared with the intact condition. A 3-dimensional laser scanning system was used to determine the graft height differences relative to the native talus. Results: The creation of an osteochondral defect caused a significant decrease in force, mean pressure, and peak pressure on the medial region of the talus ( P = .037). Implanting an osteochondral graft restored the force, mean pressure, and peak pressure on the medial region of the talus to intact levels ( P = .05). The anterior portion of the graft carried less force, while mean and peak pressures were decreased relative to intact ( P = .05). The mean difference in graft height relative to the surrounding host cartilage for the overall population was −0.2 ± 0.3 mm (range, −1.00 to 0.40 mm). Under these conditions, there was no correlation between height and pressure when the graft was sunken, flush, or proud. Conclusion/Clinical Relevance: Placement of the osteochondral graft in the most congruent position possible partially restored contact mechanics of the ankle joint. Persistent deficits in contact mechanics may be due to additional factors besides graft congruence, including structural differences in the donor cartilage when compared with the native tissue.

scholarly journals Osteochondral Lesions of the Talus – A Biomechanical Explanation for Larger OLT Shoulder Lesions Leading to Increased Patient Risk

2019 ◽  
Vol 4 (4) ◽  
pp. 2473011419S0004
Author(s):  
Peter Lawson ◽  
Pam Kumparatana ◽  
Todd Baldini ◽  
Shanthan Challa ◽  
Daniel Moon ◽  
...  
Keyword(s):  
Surface Area ◽  
Ankle Joint ◽  
Contact Area ◽  
Peak Pressure ◽  
Defect Size ◽  
Cartilage Tissue ◽  
Osteochondral Lesions ◽  
Talar Dome ◽  
Increased Risk ◽  
Donor Characteristics

Category: Ankle, Trauma Introduction/Purpose: Osteochondral lesions of the talus (OLT) are a common injury that can result in pain, disability, and risk ankle degeneration, with poor outcomes when not managed properly. Unconstrained ‘shoulder’ lesions on the medial edge of the talar dome present a particular challenge. The objective of this study was to assess the effect of increasing size of a medial OLT shoulder lesion on ankle joint contact mechanics and to determine a threshold size that would warrant bulk grafting of the defect. Our hypothesis is that larger defects will demonstrate increased pressure applied over a lesser surface area, with peak pressure progressing towards the rim of the defect, resulting in an increased risk for tissue damage and need for treatment. Methods: Nine cadaver ankle joints were dissected without disrupting the medial and lateral stabilizing ligaments. A Tekscan pressure sensor was inserted into the ankle joint. Intact specimens were axially compressed up to 800 N with the foot in neutral and again at 20° inversion, simulating ankle position during inversion injury. The specimens were then tested with progressively larger semicircular osteochondral lesions at diameters of 8, 10, 12, 14, and 16 mm that were centered on the edge of the medial talar dome, followed by a final ovoid lesion of 16x20 mm. After each lesion was created the specimens were retested. Linear mixed models adjusted for donor characteristics and assessed changes in peak pressure (MPa), contact area (mm2), peak pressure location (mm), and distance from peak pressure location to the lateral rim of the defect (mm) by defect size and ankle position. Results: For all defect sizes, mean peak pressures were significantly higher in inversion compared to neutral. Mean peak pressure magnitude progressively increased with defect size in both ankle positions. Donor characteristics did not significantly affect mean peak pressure. Contact area decreased in both positions as defect size increased, but inversion led to significantly lower contact areas than in neutral. In neutral positions, the location of peak pressure moved laterally on the talar dome but also moved closer to the defect rim as the size of the defect increased. The rim-peak pressure distance stabilized for defect sizes of 10 mm and above. In inversion, however, the rim-peak pressure distance remained unchanged at about 8 mm for all defect sizes. Conclusion: As OLT defect sizes increased, we observed an increase in peak pressure, a decrease in contact surface area, and a lateral translation of peak pressure location relative to the defect rim. Distance between location of peak pressure and defect rim decreased with neutral loading until a 10 mm defect but remained consistent in inversion loading. These findings suggest a biomechanical explanation for secondary injuries and treatment failures in larger OLT shoulder lesions due to maladaptive cartilage tissue on the dome of the talus. Larger defects (=10 mm) remain a critical point of interest with predictive clinical value for OLT outcomes.

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.

Arthroscopic Talar Dome Access Using a Standard Versus Wire-Based Traction Method for Ankle Joint Distraction

2016 ◽  
Vol 32 (7) ◽  
pp. 1367-1374 ◽  
Author(s):  
Alexej Barg ◽  
Charles L. Saltzman ◽  
Timothy C. Beals ◽  
Kent N. Bachus ◽  
Brad D. Blankenhorn ◽  
...  
Keyword(s):  
Ankle Joint ◽  
Talar Dome ◽  
Traction Method ◽  
Joint Distraction
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