Increasing efficiency by optimizing table position for elective primary THA and TKA: a prospective monocentric pilot study
Authors: Zajonz Dirk , Höhn Celina , Neumann Juliane , Angrick Christine , Möbius Robert , Huschak Gerald , Neumuth Thomas , Ghanem Mohamed , Roth Andreas 
Published: October 2020

Abstract
Introduction
Hip and knee arthroplasties are very frequently performed surgeries with high quality standards and continuous optimization potential. Intraoperative processes can be standardized and simplified by optimization of table setups in the operating room to improve the quality and to increase efficiency.

Patients and methods
The existing surgical setups for primary hip and knee arthroplasties in a university maximum care hospital with endoprosthesis center were simulated and analysed with a computer program and optimized setup suggestions were worked out, based on handover times, walking distance and ergonomic aspects determined in the program. In a prospective monocentric analysis, primary hip arthroplasties and knee arthroplasties were examined in currently used and in the new optimized setups (standard procedure according to in-house SOP, senior and main surgeons, no assistants). The surgeries were externally and independently supervised and analysed, whereby the time between incision and suture beginning, handovers per minute and handover times were documented, amongst other things. In addition, an evaluation sheet, which showed the satisfaction with the new setup, was filled by the surgical team.

Results
In the period from April 2016 to December 2018, 19 hip arthroplasties in currently used and 15 in the new optimized setup as well as 9 knee arthroplasties in currently used and 13 in the new setup were performed. Attention was paid to constant conditions in the compared groups and disruptive factors (assisted surgeries, complex surgeries, different cementings, etc.) were excluded. In the group of hip arthroplasties, the handover times were significantly different (old 1.82 +/− 1.43 s.; new 1.08 +/− 0.78 s.; p <0.001), as well as the handovers per minute (old 1.62 +/− 0.45 handovers/min.; new 2.10 +/− 0.32 handovers/min.; p = 0,001). The time between incision and suture beginning indicated no significant difference (old 53.89 +/− 18.92 min.; new 49.73 +/− 12.18 min; p = 0.466): During the knee arthroplasties, handovers per minute were significantly different (old 1.83 +/− 0.38 handovers/min.; new 2.40 +/− 0.35 handovers/min.; p = 0.002). The time between incision and suture beginning (old 71.11 +/− 20.72 min.; new 70.69 +/− 17.12 min.; p = 0.959) and the handover times (old 1.06 +/− 0.64 s.; new 0.91 +/− 0.59 s.; p = 0.152) indicated no significant difference. The evaluation of the questionnaires showed a significant difference (p < 0.001) in the group of hip arthroplasties in the category “visibility”. For the knee arthroplasties, all items except “visibility” (p = 0.261) differed significantly. Overall, a high level of staff satisfaction with the new setup was achieved.

Conclusions
In both groups, more handovers per minute could be achieved in the optimized setup and in the group of the hip arthroplasties, the handover times were significantly faster. The evaluation sheet showed a high satisfaction of the surgical staff with the new setup. No reduction of the time between incision and suture beginning could be determined. This can be attributed to a certain training effect, the adjustment to the setup modification and the low number of cases. The new setup offers a practical alternative for hip arthroplasties as well as for knee arthroplasties as it optimizes the events in the operating room in many ways. For example, there were more handovers per minute possible and passing of the surgical instruments free from interferences. Moreover, it increases the efficiency and achieves a high satisfaction of the staff.