High Cup Angle and Microseparation Increase the Wear of Hip Surface Replacements

Leslie, Ian; Williams, Sophie; Isaac, Graham; Ingham, Eileen; Fisher, John

doi:10.1007/s11999-009-0830-x

Cited by 178 publications

(186 citation statements)

References 22 publications

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“…This is consistent with the results of our multivariate model, showing no significant association between radiographic signs of impingement and high CoS or CrS levels after adjusting for contact patch to rim distance and activity level. These results are in agreement with those of Leslie et al [18] who showed increased wear rates in vitro in metal-on-metal bearings combining microseparation (a condition that could result from impingement) with outof-range cup positioning.…”

Section: Discussionsupporting

confidence: 93%

Does Femoral Neck to Cup Impingement Affect Metal Ion Levels in Hip Resurfacing?

Duff

Johnson

Wassef

et al. 2013

Clin Orthop Relat Res

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Background Impingement of the femoral neck with the acetabular component after metal-on-metal hip resurfacing arthroplasty (HRA) is a possible cause of edge loading and accelerated bearing wear. No attempt has been made to correlate radiographic impingement signs and blood metal ion levels. Questions/purposes We (1) compared serum cobalt (CoS) and chromium (CrS) concentrations between patients with and without radiographic impingement signs treated with unilateral HRA, (2) determined whether divot depth on the femoral neck correlated with CoS and CrS, and (3) assessed the predictive value of radiographic impingement signs for high levels of CoS and CrS. Methods A retrospective radiographic review of 141 patients with CoS and CrS analyses yielded 21 patients with and 120 without radiographic impingement signs (controls). Radiographic measurements included divot depth and orientation of the acetabular component to compute the contact patch to rim distance, a measure of functional head coverage. We defined a patient as having radiographic impingement signs if a remodeling of the femoral neck cortex showed a depression matching the predicted path of an impinging acetabular component. CoS and CrS were analyzed by inductively coupled plasma mass spectrometry and the radiographs were taken within 12 months of the last blood draw. Results Median CoS and CrS were greater in the impingement group than in controls in patients with less than 10-mm contact patch to rim distances. Divot depth did not correlate with CoS or CrS. In predicting elevated ion levels (C 7 lg/L), the presence of a radiographic impingement sign showed a sensitivity of 50% for CoS and 33% for CrS and a specificity of 87% for both CoS and CrS. Conclusions Radiographic impingement signs influenced CoS and CrS only when the functional head coverage was insufficient due to poor socket positioning. Radiographic impingement signs alone were not a good predictor of elevated metal ion levels. Level of Evidence Level III, diagnostic study. See Instructions for Authors for a complete description of levels of evidence.

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Section: Discussionsupporting

confidence: 93%

Does Femoral Neck to Cup Impingement Affect Metal Ion Levels in Hip Resurfacing?

Duff

Johnson

Wassef

et al. 2013

Clin Orthop Relat Res

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“…All measurements used in the study were completed by a single reader (MC). Acceptable angle ranges were set at 30°to 45°for abduction and 5°to 25°for version based on surgeon consensus and standards from previous studies [12,25,26,54].…”

Section: Methodsmentioning

confidence: 99%

“…Increased wear debris from the bearing surface can lead to osteolysis and aseptic loosening of the joint [6,16,21]. This increased wear can be seen in both hard-on-soft and hard-on-hard bearing surfaces [11,14,25,38]. Importantly, recent reports on metal-on-metal bearings describe an increased risk of tissue reactions around these bearings related to metal debris from edge loading of cups [29,41].…”

Section: Introductionmentioning

confidence: 99%

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The John Charnley Award: Risk Factors for Cup Malpositioning: Quality Improvement Through a Joint Registry at a Tertiary Hospital

Callanan

Jarrett

Bragdon

et al. 2011

Clinical Orthopaedics &Amp; Related Research

500

406

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Background Few studies have examined factors that affect acetabular cup positioning. Since cup positioning has been linked to dislocation and increased bearing surface wear, these factors affecting cup position are important considerations. Question/purposes We determined the percent of optimally positioned acetabular cups and whether patient and surgical factors affected acetabular component position. Methods We obtained postoperative AP pelvis and crosstable lateral radiographs on 2061 consecutive patients who received a THA or hip resurfacing from 2004 to 2008. One thousand nine hundred and fifty-two hips had AP pelvic radiographs with correct position of the hip center, and 1823 had both version and abduction angles measured. The AP radiograph was measured using Hip Analysis Suite TM to calculate the cup inclination and version angles, using the lateral film to determine version direction. Acceptable ranges were defined for abduction (30°-45°) and version (5°-25°).Results From the 1823 hips, 1144 (63%) acetabular cups were within the abduction range, 1441 (79%) were within the version range, and 917 (50%) were within the range for both. Surgical approach, surgeon volume, and obesity (body mass index [ 30) independently predicted malpositioned cups.

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“…Laboratory simulator studies have shown that microseparation produces stripe wear at the bearing surfaces (Figure 1) and dramatically elevated wear rates20 in MoM bearings. Simulator tests have also been carried out in an attempt to investigate the effects of head sizes and cup inclination on elevated wear20, 21 under microseparation conditions; these tests have been generally focused on a fixed translation level of 0.5 mm. A full range of parametric studies which can incorporate a wide range of variations in microseparation displacement, cup orientation and cup rim radius are currently not available with simulator tests.…”

Section: Introductionmentioning

confidence: 99%

Effect of microseparation on contact mechanics in metal‐on‐metal hip replacements—A finite element analysis

2014

Self Cite

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Some early failures of metal‐on‐metal (MoM) hip replacements associated with elevated wear have caused concerns for the use of this bearing combination. Simulator studies have shown that microseparation and its associated rim contact and edge loading may produce the most severe wear in MoM bearings. It is generally recognized that this high wear can be attributed to the high contact stress of the head on the rim of the cup. In this study, an improved finite element contact model that incorporates an elastic‐perfectly plastic material property for cobalt‐chrome alloy of the metal bearing was developed in an attempt to provide an accurate prediction of the stress and strain for the rim contact. The effects of the microseparation displacement (0.1−2 mm), cup inclination angle (25−65°) and cup rim radius (0.5−4 mm) on the contact stress/strain were investigated. The results show that a translational displacement >0.1 mm under a load >0.5 kN can produce a highly concentrated contact stress at the surface of the cup rim which can lead to plastic deformation. This study also suggests that the magnitude of translational displacement was the major factor that determined the severity of the contact conditions and level of stress and strain under microseparation conditions. Future studies will address the effect of surgical translational and rotational malposition and component design on the magnitude of microseparation, contact stress and strain and severity of wear. © 2014 The Authors. Journal of Biomedical Materials Research Part B: Applied Biomaterials Published by Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 103B: 1312–1319, 2015.

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High Cup Angle and Microseparation Increase the Wear of Hip Surface Replacements

Cited by 178 publications

References 22 publications

Does Femoral Neck to Cup Impingement Affect Metal Ion Levels in Hip Resurfacing?

Does Femoral Neck to Cup Impingement Affect Metal Ion Levels in Hip Resurfacing?

The John Charnley Award: Risk Factors for Cup Malpositioning: Quality Improvement Through a Joint Registry at a Tertiary Hospital

Effect of microseparation on contact mechanics in metal‐on‐metal hip replacements—A finite element analysis

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