Inducible displacements of the cup and the femoral head during active range of motion: Dynamic RSA studies of cemented total hip replacements

2013 ◽  
Vol 31 (11) ◽  
pp. 1686-1693 ◽  
Author(s):  
Georgios Digas ◽  
Per-Erik Johansson ◽  
Johan Kärrholm
2021 ◽  
Vol 11 (6) ◽  
pp. 2852
Author(s):  
Maeruan Kebbach ◽  
Christian Schulze ◽  
Christian Meyenburg ◽  
Daniel Kluess ◽  
Mevluet Sungu ◽  
...  

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.


2000 ◽  
Author(s):  
Mark E. Nadzadi ◽  
Douglas R. Pedersen ◽  
John J. Callaghan ◽  
Thomas D. Brown

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.


Author(s):  
Douglas M. Doud ◽  
Preston R. Beck ◽  
Donald R. Petersen ◽  
Jack E. Lemons ◽  
Alan W. Eberhardt

Postoperative dislocation of total hip replacements has been documented to occur at a rate of approximately 2.4–3.9% [1–3]. Such events may result in the transfer of titanium from the acetabular cup to the femoral head, both during the dislocation and surgical reduction of the dislocated joint [3,4]. If the head is reduced with this transfer present, the joint life expectancy, which depends on articulating surfaces remaining smooth, is reduced [4]. Although the presence of metal transfer on retrieved femoral heads after dislocation is documented, no previous studies have attempted to quantify the forces or contact stresses at which metal transfer occurs.


1975 ◽  
Vol 111 ◽  
pp. 124-130 ◽  
Author(s):  
Harlan C. Amstutz ◽  
R M Lodwig ◽  
D J Schurman ◽  
A G Hodgson

2017 ◽  
Vol 7 (2) ◽  
Author(s):  
Richard Barker Cook ◽  
Jeremy M. Latham ◽  
Robert J.K. Wood

Using a femoral head from one manufacturer on the stem of another manufacturer poses the risk that the taper interface between the components may not contact correctly and the performance of the joint will be impaired. The cohorts in this study are a combination of modular Birmingham Hip Resurfacing (BHR) and Adept femoral heads on CPT stems. The study reviews the geometry of the taper interfaces to establish if the taper clearance angles was outside of the normal range for other taper interfaces. In addition the rates of material loss from the bearings and taper and a ranking of the stem damage were reviewed to determine if the levels of loss were above that seen for other similar joints. The material loss analysis demonstrated that the rates or levels of loss from the bearings, taper and stem were no different to levels published for manufacturer matched joints and in many cases were lower. The results demonstrate that the taper clearance angles for the mixed manufacturer joints (BHR-CPT: 0.067 to -0.116, Adept-CPT: 0.101 to -0.056) were within the range of other studies and manufacturer matched clearances (0.134 to -0.149).Using components from different manufacturers has not in this instance increased the level of material loss from the joints, when compared to other similar manufacturer matched joints.


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