Literature article entitled, ¿metal-on-metal total hip arthroplasty adverse local tissue reaction¿ by charles a.Engh jr, md, et al, published by seminars in arthroplasty (2010), vol.21, pp.19-23 was reviewed for mdr reportability.The purpose of this article is to report the author¿s experience with mom bearings with large femoral heads (diameter: 36 mm) from a single manufacturer.Beginning in 2001, the authors started using the pinnacle acetabular cup, ultamet liner and head, and the asr acetabular system on 1164 patients with 1327 hips.The primary diagnosis was osteoarthritis (82.0%), followed by avascular necrosis (6.8%), developmental dysplasia (6.6%), fracture (2.7%), and rheumatoid arthritis (1.9%).In the acetabular side, the 36 mm modular component accounts for 77.5% (1029 thas), the 40 or 44 mm modular component accounts for 19.0% (258 thas), and the nonmodular asr has been placed in 3.5% (40 thas).On the femoral side, 56.7% (752 thas) are prodigy stem (depuy inc, warsaw, in), 26.8% (355 thas) are aml stem (depuy inc, warsaw, in), 11.5% (153 thas) are summit stem (depuy inc, warsaw, in), and the rest 5.0% (67 thas) are other stem designs.The current follow-up is such that 12.5% of these hips have greater than a 5-year follow-up and 22.3% have between 2- and 5-year follow-up.The mean follow-up for all available cases is 2.6 ( 1.87, 0-8) years.The authors report all known component revisions in the cohort of 1327 hips and the percentage of those revisions that were known to have a possible tissue reaction to the mom bearing.The latter diagnosis was based on the gross inspection of the wound at the time of revision, intraoperative finding of biopsies, and a light microscopic analysis of h&e stained periarticular tissue performed by a single independent pathologist with expertise in mom bearing surface pathology.There have been 17 reoperations on these 1164 patients or 1327 hips.Twelve reoperations were not associated with either gross or microscopic evidence of an adverse reaction to the metal bearing included 4 cases revised for infection, 5 revised for stem loosening, 1 for stem fracture, 1 revised for a periprosthetic fracture, and 1 for cup loosening (table 1).Five other reoperations are believed to be related to a local reaction to the mom bearing and have been confirmed with histology (table 2).Three of the 5 reactions presented with a milky-appearing fluid and a thickened joint capsule (fig.1).Two of the 5 cases had a secondary diagnosis of infection.Both of those cases were patients in which the severity of the reaction had progressed to the appearance of a pseudotumor seen at surgery with associated tissue necrosis.The first patient had a pseudotumor with a necrotic posterior portion of the gluteus medius and a small portion of necrosis in the greater trochanter.The second patient had a large pseudotumor that completely destroyed the hip abductors (fig.2).These 5 cases represent 29% (5/17) of the reoperations done in our series of mom thas.Histology has been performed on 9 of the 17 revisions.The remaining 8 cases that do not have histology either occurred before we were aware of this type of tissue reaction or there were no sign of metal reaction or infection diagnosed intraoperatively and therefore tissue was not obtained.Of the 9 cases that have had a histology consultation, 5 were positive for a histologic appearance consistent with the reaction occurring in a mom bearing.These five are listed as cases 13-17 within the attached guidance document.Please link all 17 pcs with the parent (b)(4).Each case has the impacted products and associated patient harms listed in each individual case tab within the guidance document.Case 17 of 17.Link to parent (b)(4).(b)(6) year old with bmi 32.Index tha: 06/2003.Implanted with 36-mm pinnacle cup, ultament liner, ultamet head, and large prodigy stem.Prop dx: stem fracture.Intraoperative findings: elevated blood metal ions, metallosis, light brown milky fluid in the joint capsule, broken stem, negative for infection, hypersensitivity.Complete two-stage revision 1.7 years after index tha.
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Depuy synthes is submitting this report pursuant to the provisions of 21 cfr, part 803.This report may be based on information which depuy synthes has not been able to investigate or verify prior to the required reporting date.This report does not reflect a conclusion by fda, depuy synthes or its employees that the report constitutes an admission that the device, depuy synthes, or its employees caused or contributed to the potential event described in this report.Product complaint # (b)(4).No device associated with this report was received for examination.A worldwide lot specific complaint database search, or device history record (dhr) review, was not possible because the required lot number was not provided.The information received will be retained for potential series investigations if triggered by trend analysis, post market surveillance, or other events within the quality system.Device history lot : null.Device history batch : null.Device history review : null.If information is obtained that was not available for the initial medwatch, a follow-up medwatch, a follow-up medwatch will be filed as appropriate.
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