Objectives. Mechanical wear and corrosion at the head-stem junction of total hip arthroplasties (THAs) (trunnionosis) have been implicated in their early revision, most commonly in metal-on-metal (MOM) hips. We can isolate the role of the head-stem junction as the predominant source of metal release by investigating non-MOM hips; this can help to identify clinically significant volumes of material loss and corrosion from these surfaces. Methods. In this study we examined a series of 94 retrieved metal-on-polyethylene (MOP) hips for evidence of corrosion and material loss at the
Objectives.
The Attune total knee arthroplasty (TKA) has been used in over 600 000 patients worldwide. Registry data show good clinical outcome; however, concerns over the cement-tibial interface have been reported. We used retrieval analysis to give further insight into this controversial topic. We examined 12 titanium (Ti) PFC Sigma implants, eight cobalt-chromium (CoCr) PFC Sigma implants, eight cobalt-chromium PFC Sigma rotating platform (RP) implants, and 11 Attune implants. We used a peer-reviewed digital imaging method to quantify the amount of cement attached to the backside of each tibial tray. We then measured: 1) the size of tibial tray thickness, tray projections, peripheral lips, and undercuts; and 2) surface roughness (Ra) on the backside and keel of the trays. Statistical analyses were performed to investigate differences between the two designs.Objectives
Methods
We investigated the effects on fracture healing of two up-regulators of inducible nitric oxide synthase (iNOS) in a rat model of an open femoral osteotomy: tadalafil, a phosphodiesterase inhibitor, and the recently reported nutraceutical, COMB-4 (consisting of L-citrulline, Paullinia cupana, ginger and muira puama), given orally for either 14 or 42 days. Unilateral femoral osteotomies were created in 58 male rats and fixed with an intramedullary compression nail. Rats were treated daily either with vehicle, tadalafil or COMB-4. Biomechanical testing of the healed fracture was performed on day 42. The volume, mineral content and bone density of the callus were measured by quantitative CT on days 14 and 42. Expression of iNOS was measured by immunohistochemistry.Objectives
Materials and Methods
Third-body wear is believed to be one trigger for adverse results
with metal-on-metal (MOM) bearings. Impingement and subluxation
may release metal particles from MOM replacements. We therefore
challenged MOM bearings with relevant debris types of cobalt–chrome
alloy (CoCr), titanium alloy (Ti6Al4V) and polymethylmethacrylate
bone cement (PMMA). Cement flakes (PMMA), CoCr and Ti6Al4V particles (size range
5 µm to 400 µm) were run in a MOM wear simulation. Debris allotments
(5 mg) were inserted at ten intervals during the five million cycle
(5 Mc) test. Objectives
Methods