The optimization of the OR setups is very important for increasing the efficiency as well as for quality assurance. Especially, in the case of very frequently performed surgeries, such as hip and knee arthroplasties, the quality in the operating room should be checked repeatedly and potential for improvement should be optimally exploited [7].
The results for the total hip arthroplasties showed an increase in efficiency by optimizing the operating room setups. A highly significant (p < 0.001) difference in handover times, a significant (p = 0.001) difference in the handovers per minute as well as a tendency towards a reduction in the time between incision and suture beginning could be determined, even if this was not statistically significant (p = 0.466).
This study showed that the work steps that are directly related to the table position, such as handing over surgical instruments, can be performed much more quickly and uncomplicatedly, thus optimizing the entire surgical procedure. Although the time between incision and suture beginning did not differ significantly, we assume that the reason for this is the training period with a training curve into the new setup and low number of cases. To reduce distortion due to interindividual deviations (different operators and scrub nurses), it was determined how many handovers were made per minute, since this value is more valid than the pure time between incision and suture beginning, which is influenced by many other factors. The significant difference in the number of handovers per minute (p = 0.001) shows the notable increase of efficiency. This was also demonstrated by the highly significantly (p < 0.001) faster handover times in the new setup.
In the new setup, there are more handovers per minute, but generally also more handovers in total than in the old setup. We noticed this aspect when evaluating the data and the higher number of handovers could cause an increase in handovers per minute. Unfortunately, we couldn’t find an exact reason for this phenomenon even after consultation with the different surgeons. We could imagine interindividual differences between the surgeons or that the new setup invites more handovers due to the easier passing of the instruments and the ergonomics.
To ensure that the surgical procedure for hip arthroplasties functions as optimally as possible, it is important to ensure that the table position is changed according to the description in the Materials and methods part when the surgeon and the first assistant change positions for inserting the shaft. The scrub nurse moves the front and side tables behind the first assistant, with the rasps and instruments used for shaft insertion lying on the outer table on the side of the leg to be operated on. But if the rasps for the insertion of the shaft are on the table, which is directly behind the operating table and does not have to be moved, the way for the scrub nurse becomes too long, why it is important to ensure at the beginning of the surgery that the instrument table for the shaft is on the side to be operated on.
Looking at the results for total knee arthroplasties, the increase of efficiency was initially not as visible as for hip surgeries.
The handover times per minute differed significantly (p = 0.002), the handover times did not differ significantly (p = 0.152) and the time between incision and suture beginning did not differ significantly (p = 0.959). As with the hip arthroplasties, we assume that this was due to the training period with a training curve in the new setup and the low number of cases. On the other hand, the surgical procedure for knee operations is very complex. The insertion of a knee endoprosthesis requires very large surgical steps during which there are hardly any handovers, but there are again phases with very many handovers [13]. These phases with large surgical steps are independent of the table position, more susceptible to interindividual differences between the surgeons and constitute a large part of the surgery time. They are, to a great extent, influenced by the surgeon’s performance, complications and other factors. Nevertheless, there were also significant differences in the handovers per minute (p = 0.002), which could be assumed to be a valid measure of efficiency.
A review by Pokrywka and Byers on airflow and contamination of surgical wounds described that unnecessary movement during the surgery, as well as entering and leaving the room, interrupts the sterile airflow and contaminants are not sufficiently removed from the sterile area. With a high level of activity in the operating room, the bacterial count of microorganisms in the air increases [14]. Contamination of the air in the immediate surgical area can also result in contamination of the surgical field, since the air plays a major role in the transmission of pathogens during the surgery [15]. In the new surgical setup, special attention was therefore paid to optimizing hygiene standards. Observation of the operating activities showed that the personnel, especially the surgeon and the scrub nurse need to carry out considerably fewer rotational movements in order to hand over the instruments. Unfortunately, this could not be measured validly and therefore referred to pure observation. Theoretically, the nurse only has to rotate 90 degrees to the instrument table on her right and left side to reach the instruments. However, the observations showed that the nurse needed to rotate considerably less by using the freedom of movement of the arms. The surgeon, as well, has a theoretical rotational movement range of 90 degrees to the scrub nurse, which he also reduces by using the arms. In the currently-used setup, significantly more rotational movements are necessary [9], so that air turbulence could be reduced with the new setup. In addition, it is not necessary to hand over the instruments from behind via the surgeon’s back, as was often the case with the currently-used setup. If the instruments were handed over via the back, the surgeon could not ensure that all instruments were visibly clean [16] and the risk for contamination would therefore increase.
In the new setup, the instrument tables are hypothetically closer to the operating table and thus more in the protected area, which is characterized by a stable flow of air filtered from suspended matter, which is virtually sterile and separates the area of operating table and instrument table from the rest of the surroundings [15].
The results of the questionnaire showed a very high level of staff satisfaction with the new setup for both hip and knee arthroplasties.
In the setup for hip arthroplasties, only the item “visibility” differed significantly between the four occupational groups. In the case of knee arthroplasties, all items except “visibility” differed significantly. This could be due to the fact that everyone involved in knee surgery was close to the joint to be operated on than during hip replacement surgery and therefore all had a very good view. The setup for the knee enabled the scrub nurse to stand directly at the end of the table and thus gave a very good overview. In the case of hip arthroplasties, however, the nurse was positioned laterally offset from the operating table to be able to reach the surgeon easily, but thus lost some visibility, because in the case of the large surgical steps, one of the surgeons often stood between the nurse and thereby clear view of the operating field. The surgeon also stood directly at the hip and had an optimal view. Since the instrument tables for knee arthroplasties were located behind the operating table, they took up more space in the room and thus had a very strong influence on the walking distance, the available space for each individual as well as compliance with hygiene standards and overall satisfaction. As a result, although everyone could see well, all the other categories differed significantly between occupational groups. The setup for the hip arthroplasties was more at the side of the operating table and this tood up less space in the room, or rather fit better into the operating room. Therefore, all categories except “visibility” were assessed similarly by all occupational groups and did not differ significantly.
The questionnaire showed a very high level of satisfaction, which is particularly important because the satisfaction of the individual team members and performance are positively correlated [17]. This shows that it is important to look at the staff satisfaction during every intervention, because only satisfied team members can achieve full performance. The publication discussed the performance-caused satisfaction theory, but ultimately assumed a circular relationship [17].
Further possibilities for increasing efficiency were discussed in Fong’s publication. Among other things, it mentioned cooperation always with the same team, less use of instruments by the surgeon and increased familiarity within the team. It is also emphasized that communication controls the operating room and teamwork is the foundation for a successful surgery. Every team member should be heard [1]. From these points of view, the importance of the questionnaire for the good execution of the new setups becomes apparent. If all team members are involved and are satisfied with the new setup, it can be implemented even better. Therefore, it is even more important that the results of the survey are so positive and that all team members report a high level of satisfaction with the setup for both hip and knee arthroplasties.
Limitations
Due to the small and inconsistent number of cases, no change in surgery time could be detected. Even assuming a learning curve with the new setup, larger case numbers would be necessary to confirm this assumption. Therefore, no conclusive statement on the reduction of surgery time was possible in this study. Individual procedures of each surgeon contributed to the contamination of the data. This was corrected as all surgeons performed operations in both the old and the new setup.