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Detection of incorrect manufacturer labelling of hip components

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ABSTRACT

We describe the case of a 53-year-old man who underwent a left metal-on-metal hip resurfacing in 2015. Component size mismatch (CSM) was suspected because of the patient’s immediate post-operative mechanical symptoms and high metal ion levels. Surgical notes indicated the appropriate combinations of implants were used. However, we detected a mismatch using computed tomography. Revision was performed and subsequent measurements of explanted components confirmed the mismatch. To our knowledge, this case is the first report of a CT method being used in a patient to pre-operatively identify CSM.

Electronic supplementary material: The online version of this article (doi:10.1007/s00256-016-2478-4) contains supplementary material, which is available to authorized users

No MeSH data available.


Photo of the revised Adept hip resurfacing removed from the 53-year-old gentleman. Manufacturer labels in the surgical notes record the components as being a 56-mm cup designed for a 48-mm head and a 48-mm head. Engravings (red arrows) and coordinate measuring machine measurements confirm the CSM, as the cup is actually a 56-mm cup designed for a 50-mm head
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Fig6: Photo of the revised Adept hip resurfacing removed from the 53-year-old gentleman. Manufacturer labels in the surgical notes record the components as being a 56-mm cup designed for a 48-mm head and a 48-mm head. Engravings (red arrows) and coordinate measuring machine measurements confirm the CSM, as the cup is actually a 56-mm cup designed for a 50-mm head

Mentions: The resurfacing was revised 10 weeks post-primary surgery, with the Adept hip resurfacing (MatOrtho, Surrey, UK) exchanged for a Trinity Metafix (Corin, Cirencester, UK). The explanted Adept hip resurfacing components, both acetabular and femoral components, were sent to the London Implant Retrieval Centre for analysis. On visual inspection, implant labelling pointed to a bearing size mismatch (Fig. 6). These measurements were confirmed using a coordinate measuring machine (internal diameter of the cup = 49.98 mm, outer diameter of the head = 47.84 mm). Wear analysis of both components was also performed. The volume of wear in the acetabular component was 20.59 mm3. This gives a predicted 1-year wear of 107 mm3. The volume of wear of the femoral head component was 10.14 mm3. This gives a predicted 1-year wear of 47.84 mm3. Under standard walking conditions, with correctly positioned components, assuming 1.9 million cycles per annum [6], the expected wear rate should be less than 2 mm3/year [7].Fig. 6


Detection of incorrect manufacturer labelling of hip components
Photo of the revised Adept hip resurfacing removed from the 53-year-old gentleman. Manufacturer labels in the surgical notes record the components as being a 56-mm cup designed for a 48-mm head and a 48-mm head. Engravings (red arrows) and coordinate measuring machine measurements confirm the CSM, as the cup is actually a 56-mm cup designed for a 50-mm head
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC5121176&req=5

Fig6: Photo of the revised Adept hip resurfacing removed from the 53-year-old gentleman. Manufacturer labels in the surgical notes record the components as being a 56-mm cup designed for a 48-mm head and a 48-mm head. Engravings (red arrows) and coordinate measuring machine measurements confirm the CSM, as the cup is actually a 56-mm cup designed for a 50-mm head
Mentions: The resurfacing was revised 10 weeks post-primary surgery, with the Adept hip resurfacing (MatOrtho, Surrey, UK) exchanged for a Trinity Metafix (Corin, Cirencester, UK). The explanted Adept hip resurfacing components, both acetabular and femoral components, were sent to the London Implant Retrieval Centre for analysis. On visual inspection, implant labelling pointed to a bearing size mismatch (Fig. 6). These measurements were confirmed using a coordinate measuring machine (internal diameter of the cup = 49.98 mm, outer diameter of the head = 47.84 mm). Wear analysis of both components was also performed. The volume of wear in the acetabular component was 20.59 mm3. This gives a predicted 1-year wear of 107 mm3. The volume of wear of the femoral head component was 10.14 mm3. This gives a predicted 1-year wear of 47.84 mm3. Under standard walking conditions, with correctly positioned components, assuming 1.9 million cycles per annum [6], the expected wear rate should be less than 2 mm3/year [7].Fig. 6

View Article: PubMed Central - PubMed

ABSTRACT

We describe the case of a 53-year-old man who underwent a left metal-on-metal hip resurfacing in 2015. Component size mismatch (CSM) was suspected because of the patient’s immediate post-operative mechanical symptoms and high metal ion levels. Surgical notes indicated the appropriate combinations of implants were used. However, we detected a mismatch using computed tomography. Revision was performed and subsequent measurements of explanted components confirmed the mismatch. To our knowledge, this case is the first report of a CT method being used in a patient to pre-operatively identify CSM.

Electronic supplementary material: The online version of this article (doi:10.1007/s00256-016-2478-4) contains supplementary material, which is available to authorized users

No MeSH data available.