The incidence of noise generation arising from the large-diameter Delta Motion ceramic total hip bearing
Nuffield Orthopaedic Centre, Oxford, Windmill Road, Headington, Oxford OX3 7LD, UK.Bone and Joint Journal (Impact Factor: 1.96). 02/2013; 95-B(2):160-5. DOI: 10.1302/0301-620X.95B2.30450
Noise generation has been reported with ceramic-on-ceramic articulations in total hip replacement (THR). This study evaluated 208 consecutive Delta Motion THRs at a mean follow-up of 21 months (12 to 35). There were 141 women and 67 men with a mean age of 59 years (22 to 84). Patients were reviewed clinically and radiologically, and the incidence of noise was determined using a newly described assessment method. Noise production was examined against range of movement, ligamentous laxity, patient-reported outcome scores, activity level and orientation of the acetabular component. There were 143 silent hips (69%), 22 (11%) with noises other than squeaking, 17 (8%) with unreproducible squeaking and 26 (13%) with reproducible squeaking. Hips with reproducible squeaking had a greater mean range of movement (p < 0.001) and mean ligament laxity (p = 0.004), smaller median head size (p = 0.01) and decreased mean acetabular component inclination (p = 0.02) and anteversion angle (p = 0.02) compared with the other groups. There was no relationship between squeaking and age (p = 0.13), height (p = 0.263), weight (p = 0.333), body mass index (p = 0.643), gender (p = 0.07) or patient outcome score (p = 0.422). There were no revisions during follow-up. Despite the surprisingly high incidence of squeaking, all patients remain satisfied with their hip replacement. Cite this article: Bone Joint J 2013;95-B:160-5.
- "Some designs have an offset of the cup, which lateralized the head center related . This last issue might have serious but currently unrecognized drawbacks: • a high risk of squeaking  . For Tai et al. , this rate is independent of factors such as anteversion or inclination of the cup or demographic data but is secondary to thin insert concept for large head diameter; • an increased risk of edge loading  and also greater subluxation effect (with the risk of insert delamination ); • a risk of interruption of the lubrication film (also explaining the former complications ); • an increase in bearing friction coefficient  (even higher than in 48 mm diameter for a metal-on-metal bearing); • an increase in torsion stresses on the Morse taper that may produce a trunion wear on ceramic head  . "
Article: Response to the letter by B. Masson
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- "Indeed recent MoM resurfacing research using AP X-rays suggests that low inclination is beneficial, particularly for small bearings.26 However, in both established8 and contemporary27 CoC bearings, a combination of low inclination and low anteversion led to high incidences of posterior edge loading wear and squeaking. This is the cup orientation at greatest risk of posterior edge loading from muscle action (Fig. 6), and so low inclination should be combined with higher anteversion to provide better coverage of the head throughout the range of motion. "
ABSTRACT: Edge loading causes clinical problems for hard-on-hard hip replacements, and edge loading wear scars are present on the majority of retrieved components. We asked the question: are the lines of action of hip joint muscles such that edge loading can occur in a well-designed, well-positioned acetabular cup? A musculoskeletal model, based on cadaveric lower limb geometry, was used to calculate for each muscle, in every position within the complete range of motion, whether its contraction would safely pull the femoral head into the cup or contribute to edge loading. The results show that all the muscles that insert into the distal femur, patella, or tibia could cause edge loading of a well-positioned cup when the hip is in deep flexion. Patients frequently use distally inserting muscles for movements requiring deep hip flexion, such as sit-to-stand. Importantly, the results, which are supported by in vivo data and clinical findings, also show that risk of edge loading is dramatically reduced by combining deep hip flexion with hip abduction. Patients, including those with sub-optimally positioned cups, may be able to reduce the prevalence of edge loading by rising from chairs or stooping with the hip abducted. © 2013 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res.
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ABSTRACT: The reintroduction of metal-on-metal (M-M) bearing components in total hip arthroplasty (THA) occurred with small-diameter heads (28–32 mm) in the late 1980s and gave excellent results up to 15 years of follow-up (Dastane et al. 2011; Grübl et al. 2007; Migaud et al. 2011). Shortly thereafter, M-M hip resurfacing (SRA) resurged, and favorable outcomes are currently reported at follow-up exceeding 12 years (Amstutz et al. 2010; Coulter et al. 2012; Treacy et al. 2011). From this rapid overview of the literature on metallic articulations, one may erroneously conclude that bearing diameter has no influence on survival of M-M articulations. Currently, there is growing controversy regarding M-M bearings considering adverse reactions to metallic debris (ARMD) and concerns about blood ion elevation (Engh et al. 2010; Glyn-Jones et al. 2009; Hart et al. 2012; Heneghan et al. 2012). In fact, these side effects were rare at the time small M-M bearings were reintroduced: Rising metallic ion levels in blood were low (Grübl et al. 2007), and aseptic lymphocytic vasculitis-associated lesions (ALVAL) were extremely uncommon (
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