Comparision of Cup Anteversion and Tilt Effects on Dislocation Propensity for Small-Head-Size Total Hip Replacements

2000 ◽  
Author(s):  
Mark E. Nadzadi ◽  
Douglas R. Pedersen ◽  
John J. Callaghan ◽  
Thomas D. Brown
Keyword(s):  
Range Of Motion ◽  
Three Dimensional ◽  
Element Model ◽  
Head Size ◽  
Modular System ◽  
Total Hip ◽  
Total Hip Replacements ◽  
Apparent Stiffness ◽  
Hip Replacements ◽  
Laboratory Examinations

Abstract While dislocation is a leading cause of total hip replacement failure, empirical observations far outnumber systematic laboratory examinations of this phenomenon. A previously validated three-dimensional, non-linear, contact finite element model was used to study how surgical placement affects dislocation propensity. The computational model employed a widely used 22mm modular system, and examined range of motion prior to impingement as well as peak moment developed to resist dislocation under a typical leg-crossing maneuver. Results were compared to a previous study of an otherwise similar 26mm modular head system, using the same formulation. Similar trends occurred. Increasing tilt and/or anteversion increased both the range of motion and the peak resisting moment, while apparent stiffness seemed to be unaffected. Further, impingement range of motion was independent of head size, but peak resisting moment was nearly 25% less for the 22mm head sizes.

scholarly journals An MRI-Based Patient-Specific Computational Framework for the Calculation of Range of Motion of Total Hip Replacements

2021 ◽  
Vol 11 (6) ◽  
pp. 2852
Author(s):  
Maeruan Kebbach ◽  
Christian Schulze ◽  
Christian Meyenburg ◽  
Daniel Kluess ◽  
Mevluet Sungu ◽  
...  
Keyword(s):  
Range Of Motion ◽  
Internal Rotation ◽  
Computer Aided Design ◽  
External Rotation ◽  
Patient Specific ◽  
Computational Framework ◽  
Total Hip ◽  
Total Hip Replacements ◽  
Significant Difference ◽  
Hip Replacements

The calculation of range of motion (ROM) is a key factor during preoperative planning of total hip replacements (THR), to reduce the risk of impingement and dislocation of the artificial hip joint. To support the preoperative assessment of THR, a magnetic resonance imaging (MRI)-based computational framework was generated; this enabled the estimation of patient-specific ROM and type of impingement (bone-to-bone, implant-to-bone, and implant-to-implant) postoperatively, using a three-dimensional computer-aided design (CAD) to visualize typical clinical joint movements. Hence, patient-specific CAD models from 19 patients were generated from MRI scans and a conventional total hip system (Bicontact® hip stem and Plasmacup® SC acetabular cup with a ceramic-on-ceramic bearing) was implanted virtually. As a verification of the framework, the ROM was compared between preoperatively planned and the postoperatively reconstructed situations; this was derived based on postoperative radiographs (n = 6 patients) during different clinically relevant movements. The data analysis revealed there was no significant difference between preoperatively planned and postoperatively reconstructed ROM (∆ROM) of maximum flexion (∆ROM = 0°, p = 0.854) and internal rotation (∆ROM = 1.8°, p = 0.917). Contrarily, minor differences were observed for the ROM during maximum external rotation (∆ROM = 9°, p = 0.046). Impingement, of all three types, was in good agreement with the preoperatively planned and postoperatively reconstructed scenarios during all movements. The calculated ROM reached physiological levels during flexion and internal rotation movement; however, it exceeded physiological levels during external rotation. Patients, where implant-to-implant impingement was detected, reached higher ROMs than patients with bone-to-bone impingement. The proposed framework provides the capability to predict postoperative ROM of THRs.

THREE-DIMENSIONAL MORPHOMETRY OF NATIVE ACETABULUM IN RELATION TO DESIGN AND IMPLANTATION OF CANINE TOTAL HIP REPLACEMENTS

2012 ◽  
Vol 24 (06) ◽  
pp. 549-555 ◽  
Author(s):  
Ching-Ho Wu ◽  
Cheng-Chung Lin ◽  
Tung-Wu Lu ◽  
Lih-Seng Yeh
Keyword(s):  
Total Hip Replacement ◽  
Hip Replacement ◽  
Quantitative Data ◽  
Three Dimensional ◽  
Morphological Parameters ◽  
3D Ct ◽  
Total Hip ◽  
Acetabular Orientation ◽  
Total Hip Replacements ◽  
Hip Replacements

Total hip replacement (THR) has been one of the main choices in treating dysplasia and other disabling conditions of the coxofemoral joint of large-breed dogs. Quantitative data of the three-dimensional (3D) morphology of the native normal acetabulum will be helpful for better design and implantation of prosthetic components. However, 3D orientation and morphological parameters of the native acetabulum in large-breed dogs are rarely reported. The purposes of the study were to measure the values of the 3D morphological parameters of the native acetabulum in Labrador Retriever dogs, namely acetabular orientation in relation to the pelvis, as well as the radius, angle between ventral and dorsal rims, and the distance from the center to the dorsal rim of the acetabulum using a 3D CT-derived model. The data will be useful for developing a more accurate guideline for improving current THR designs and for more accurate placement of the acetabulum component during THR surgery.

scholarly journals Design Study on Customised Piezoelectric Elements for Energy Harvesting in Total Hip Replacements

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3480
Author(s):  
Hans-E. Lange ◽  
Rainer Bader ◽  
Daniel Kluess
Keyword(s):  
Energy Harvesting ◽  
Power Output ◽  
Piezoelectric Element ◽  
Element Model ◽  
Design Study ◽  
Total Hip ◽  
Total Hip Replacements ◽  
Hip Replacements ◽  
Therapeutic Measures

Energy harvesting is a promising approach to power novel instrumented implants that have passive sensory functions or actuators for therapeutic measures. We recently proposed a new piezoelectric concept for energy harvesting in total hip replacements. The mechanical implant safety and the feasibility of power generation were numerically demonstrated. However, the power output for the chosen piezoelectric element was low. Therefore, we investigated in the present study different geometry variants for an increased power output for in vivo applications. Using the same finite element model, we focused on new, customised piezoelectric element geometries to optimally exploit the available space for integration of the energy harvesting system, while maintaining the mechanical safety of the implant. The result of our iterative design study was an increased power output from 29.8 to 729.9 µW. This amount is sufficient for low-power electronics.

Range of Motion Studies for Total Hip Replacements

1975 ◽  
Vol 111 ◽  
pp. 124-130 ◽  
Author(s):  
Harlan C. Amstutz ◽  
R M Lodwig ◽  
D J Schurman ◽  
A G Hodgson
Keyword(s):  
Range Of Motion ◽  
Total Hip ◽  
Total Hip Replacements ◽  
Hip Replacements ◽  
Motion Studies
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