Total knee arthroplasty (TKA) systems are designed to maximize the longevity of the implant. However, an unusually high rate of aseptic tibial tray loosening was observed in the DePuy ATTUNE ® total knee arthroplasty system (DePuy Synthes, Warsaw, USA). Affected patients noted symptoms of instability and reproducible pain at the bone-implant interface. However, there was no radiographic evidence of lucency or implant failure. Intra-operatively, the tibial component was grossly loose and lacked adhered cement. We hypothesize that the loosening is due to the smooth architecture of the undersurface of the tibial component, lacking either grit blasting or porous coating.

This report presents a previously undescribed case and treatment of bilateral four-part proximal humerus (PH) fracture-dislocations presented in a 61-year-old Caucasian male patient following a first-time seizure episode. The patient was treated with bilateral reverse total shoulder arthroplasty due to pre-existing glenohumeral arthritis and rotator cuff atrophy. The surgery was successful, and the patient's postoperative recovery was uneventful. Fractures of the proximal humerus are a relatively common adult osteoporotic fracture; however, posterior fracture-dislocations of the PH, frequently related to motor vehicle accidents, seizures, or electrical shock, are remarkably scarce. A treatment algorithm for these injuries is lacking.