Introduction: Fast-setting high viscosity cement was introduced in the last decade, offering arthroplasty surgeons the benefit of shortened setting time. This could reduce the operating time, which may reduce the risk of infection and improve theatre efficiency. PALACOS® Fast R+G high viscosity cement has an average setting time of less than 6 minutes (30% faster than regular PALACOS® R+G) due to the lack of a waiting phase. The aim of this study was to investigate the safety of total knee arthroplasty performed using this fast-setting, high viscosity cement and short-term radiological outcomes. Materials and methods: This single surgeon case series looked at 344 primary TKAs performed using PALACOS® fast R+G cement from January 2016 to March 2020. Data were collected on patient demographics, perioperative events, and complications. Radiographs taken immediately post-operatively and at the one-year follow-up were analysed using the Knee Society Roentgenographic Evaluation and Scoring System (KSRESS). Results: This case series included 313 consecutive patients (31 bilateral) with a mean age of 70 years (range 44-93). A total of 237 patients (76%, 262 TKA patients) had a minimum one-year follow-up. No adverse events were noted perioperatively; ten patients had superficial wound issues and were managed successfully with wound care and/or oral antibiotics. Six (1.7%) patients underwent re-operation in the study period. These included one DAIR, one staged revision for deep infection, two revisions for instability, one manipulation under anaesthetic for stiffness, and one patella internal fixation for fracture. The mean combined valgus angle for the prosthesis was 183.1° (range 177.7° to 187.8°), indicating adequate alignment. At one-year follow-up, no radiographs demonstrated any new loosening or worsening of any previously noted radiolucent lines. Conclusion: This study reports the largest case series that looks at the use of fast-setting bone cement in primary TKA. It demonstrates good safety, as evidenced by a low reoperation rate, deep infection rate, and no adverse events during implantation. Fast-setting cement offers the promise of improving theatre efficiency and decreasing total running costs. Further studies are needed to provide data on improved theatre efficiency, cost savings and the longevity of implanted knees utilising this cement.

This study was conducted to define the molecular mechanism of fasting-induced down-regulation of neuronal nitric oxide synthase (nNOS) expression in the hypothalamic paraventricular nucleus (PVN). Rats were adrenalectomized (ADX), and then either underwent food deprivation or received varying doses of dexamethasone for 48 h. The brain tissues were processed for NADPH-diaphorase (NADPH-d) staining, a histochemical marker of nNOS enzyme activity. Both the ADX and the sham operated rats showed a significant weight loss after 48 h of food deprivation. Food deprivation decreased the number of NADPH-d containing cells in the PVN of sham rats, however, not in the ADX rats. Dexamethasone dose- dependently decreased NADPH-d cells in the PVN of ADX rats. The effect of ADX or dexamethasone was limited to the parvocellular subdivision of PVN. These results suggest that the adrenal glucocorticoids may down-regulate nNOS expression in the PVN during food deprivation.
*Adrenalectomy ; Animals ; Biological Markers ; Dexamethasone/blood/pharmacology ; Down-Regulation/physiology ; Fasting/*physiology ; Food Deprivation/physiology ; Glucocorticoids/blood/pharmacology ; Male ; NADPH Dehydrogenase/*metabolism ; Nitric-Oxide Synthase/*metabolism ; Paraventricular Hypothalamic Nucleus/*enzymology ; Rats ; Rats, Sprague-Dawley ; Support, Non-U.S. Gov't