scholarly journals Influence of Different Patellofemoral Design Variations Based on Genesis II Total Knee Endoprosthesis on Patellofemoral Pressure and Kinematics

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Ulf G. Leichtle ◽  
Barbara Lange ◽  
Yvonne Herzog ◽  
Peter Schnauffer ◽  
Carmen I. Leichtle ◽  
...  
Keyword(s):  
Original Design ◽  
Interindividual Differences ◽  
Knee Simulator ◽  
Custom Made ◽  
Total Knee ◽  
Genesis Ii ◽  
Design Options ◽  
Patellofemoral Kinematics ◽  
Patellofemoral Pressure ◽  
Knee Endoprosthesis

In total knee arthroplasty (TKA), patellofemoral groove design varies greatly and likely has a distinct influence on patellofemoral biomechanics. To analyse the selective influence, five patellofemoral design variations were developed based on Genesis II total knee endoprosthesis (original design, being completely flat, being laterally elevated, being medially elevated, and both sides elevated) and made from polyamide using rapid prototyping. Muscle-loaded knee flexion was simulated on 10 human knee specimens using a custom-made knee simulator, measuring the patellofemoral pressure distribution and tibiofemoral and patellofemoral kinematics. The measurements were carried out in the native knee as well as after TKA with the 5 design prototypes. The overall influence of the different designs on the patellofemoral kinematics was small, but we found detectable effects for mediolateral tilt (p<0.05 for 35°–80° flexion) and translation of the patella (p<0.045 for 20°–65° and 75°–90°), especially for the completely flat design. Considering patellofemoral pressures, major interindividual differences were seen between the designs, which, on average, largely cancelled each other out. These results suggest that the elevation of the lateral margin of the patellofemoral groove is essential for providing mediolateral guidance, but smooth contouring as with original Genesis II design seems to be sufficient. The pronounced interindividual differences identify a need for more patellofemoral design options in TKA.

scholarly journals Influence of Patella thickness on Patellofemoral pressure in total knee Arthroplasty

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Hidenori Tanikawa ◽  
Mitsunori Tada ◽  
Ryo Ogawa ◽  
Kengo Harato ◽  
Yasuo Niki ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Joint ◽  
Knee Arthroplasty ◽  
Knee Flexion ◽  
Patellofemoral Joint ◽  
Joint Function ◽  
Custom Made ◽  
Total Knee ◽  
Patellar Thickness ◽  
Patellofemoral Pressure

Abstract Background Patellofemoral complications are one of the major issues after total knee arthroplasty (TKA). Excessive patellofemoral joint pressure is associated with complications after TKA surgery, and the amount of patellar osteotomy has a direct effect on patellofemoral joint pressure. The purpose of this study was to evaluate the influence of patella thickness on patellofemoral pressure in TKA. Methods Five freshly frozen cadavers were operated with a custom-made Stryker posterior stabilizing type knee joint prosthesis. Patellofemoral joint pressure was measured using a pressure sensor, with the knee joint flexed from 90 to 110 degrees, and with patellar thickness of − 2 mm to + 4 mm. Results Increasing or decreasing patellar thickness significantly increased or decreased patellofemoral pressure. Regarding knee flexion angle, patellofemoral pressure increased with increasing patellar thickness at all flexion angles, but the pressure increase was greatest at 90 degrees of knee flexion and smallest at 110 degrees. Conclusions The amount of patellar osteotomy influences the patellofemoral pressure. Surgeons should avoid increasing patella thickness, since the resulting increased patellofemoral pressure may reduce knee joint function.

scholarly journals Influence of Patella Thickness on Patellofemoral Pressure in Total Knee Arthroplasty

2020 ◽  
Author(s):  
Hidenori Tanikawa ◽  
Mitsunori Tada ◽  
Ryo Ogawa ◽  
Kengo Harato ◽  
Yasuo Niki ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Joint ◽  
Knee Arthroplasty ◽  
Knee Flexion ◽  
Patellofemoral Joint ◽  
Joint Function ◽  
Custom Made ◽  
Total Knee ◽  
Patellar Thickness ◽  
Patellofemoral Pressure

Abstract Background: Patellofemoral complications are one of the major issues after total knee arthroplasty (TKA). Excessive patellofemoral joint pressure is associated with complications after TKA surgery, and the amount of patellar osteotomy has a direct effect on patellofemoral joint pressure. The purpose of this study was to evaluate the influence of patella thickness on patellofemoral pressure in TKA.Methods. Five freshly frozen cadavers were operated with a custom-made Stryker posterior stabilizing type knee joint prosthesis. Patellofemoral joint pressure was measured using a pressure sensor, with the knee joint flexed from 90 to 110 degrees, and with patellar thickness of -2mm to +4mm.Results: Increasing or decreasing patellar thickness significantly increased or decreased patellofemoral pressure. Regarding knee flexion angle, patellofemoral pressure increased with increasing patellar thickness at all flexion angles, but the pressure increase was greatest at 90 degrees of knee flexion and smallest at 110 degrees.Conclusions: The amount of patellar osteotomy influences the patellofemoral pressure. Surgeons should avoid increasing patella thickness, since the resulting increased patellofemoral pressure may reduce knee joint function.

Aortic Remodeling After Custom-Made Candy-Plug for Distal False Lumen Occlusion in Aortic Dissection

2021 ◽  
pp. 152660282199672
Author(s):  
Ahmed Eleshra ◽  
Fiona Rohlffs ◽  
Konstantinos Spanos ◽  
Giuseppe Panuccio ◽  
Franziska Heidemann ◽  
...  
Keyword(s):  
Aortic Dissection ◽  
Clinical Success ◽  
False Lumen ◽  
High Rate ◽  
Single Center ◽  
Original Design ◽  
Mortality And Morbidity ◽  
Custom Made ◽  
Aortic Remodeling

Purpose: To report a single-center experience with the use of a custom-made Candy-Plug (CP) for distal false-lumen (FL) occlusion in subacute and chronic aortic dissection (AD). Materials and Methods: A retrospective single-center analysis was conducted on consecutive patients with subacute and chronic AD who were treated with a custom-made CP for distal FL occlusion using 3 design generations (CP I to CP III) from October 2013 to September 2019. Results: A custom-made CP was used in 57 patients. Of these, 34 patients (29 males, mean age 62±10 years) were treated with a CP I vs 23 patients (16 males, mean age 59±17 years) with CP II/III. Technical success was achieved in 57 (100%) patients. Clinical success was achieved in 54 (95%) patients; 33 (97%) in CP I group vs 21 (91%) patients in CP II/III group, p=0.116. The mean hospital stay was 10±8 days (9±5 days in CP I group vs 13±9 days in CP II/III, p=0.102). The 30-day computed tomography angiography (CTA) confirmed successful CP placement at the intended level in all patients within both groups. Early complete FL occlusion was achieved in 50 (88%) patients; 30 (88%) patients in CP I group vs 20 (87%) in CP II/III group, p=0.894. Follow up CTA was available in 44 (77%) patients. Of these; 30/34 (88%) patients in CP I group with mean follow-up 29±17 months) vs. 14/23 (61%) patients with mean follow-up 14±5 months in CP II/III group. Thoracic aortic remodeling was achieved in 34/44 (77%) patients; 25/30 (83%) patients in CP I group vs 9/14 (64%) patients in CP II/III group, p=0.197. The aneurysm size remained stable in 9/44 (20%) patients; 5/30 (17%) patients in CP I group vs 4/14 (29%) patients in CP II/III group, p=0.741. The thoracic aneurysm increased size was seen in 1/44 (2%) patient. This patient was in CPII/III group. Conclusion: CP technique using custom-made devices is technically feasible with a low mortality and morbidity, and a high rate of aortic remodeling. Both, the original design (CP I) and newer designs with a self-closing central sleeve (CP II and CP III) showed similar excellent outcomes.

Custom-made rotating hinge total knee replacement in a patient with congenital tibial deficiency avoids the need for amputation

2012 ◽  
Vol 20 (12) ◽  
pp. 2476-2479 ◽  
Author(s):  
A. McGrath ◽  
M. D. Sewell ◽  
G. Datta ◽  
G. W. Blunn ◽  
T. W. R. Briggs ◽  
...  
Keyword(s):  
Total Knee Replacement ◽  
Knee Replacement ◽  
Custom Made ◽  
Rotating Hinge ◽  
Total Knee

Simulating Dynamic Activities Using a Five-Axis Knee Simulator

2005 ◽  
Vol 127 (1) ◽  
pp. 123-133 ◽  
Author(s):  
Lorin P. Maletsky ◽  
Ben M. Hillberry
Keyword(s):  
Sagittal Plane ◽  
Compressive Force ◽  
Knee Prostheses ◽  
Plane Model ◽  
Knee Simulator ◽  
Specific Loading ◽  
Total Knee ◽  
Five Axis ◽  
Cadaveric Knee ◽  
Good Agreement

This work describes the design and capabilities of the Purdue Knee Simulator: Mark II and a sagittal-plane model of the machine. This five-axis simulator was designed and constructed to simulate dynamic loading activities on either cadaveric knee specimens or total knee prostheses mounted on fixtures. The purpose of the machine was to provide a consistent, realistic loading of the knee joint, allowing the kinematics and specific loading of the structures of the knee to be determined based on condition, articular geometry, and simulated activity. The sagittal-plane model of the knee simulator was developed both to predict the loading at the knee from arbitrary inputs and to generate the necessary inputs required to duplicate specified joint loading. Measured tibio-femoral compressive force and quadriceps tension were shown to be in good agreement with the predicted loads from the model. A controlled moment about the ankle-flexion axis was also shown to change the loading on the quadriceps.

Sign in / Sign up

Export Citation Format

Share Document