Reducing costly falls after total knee arthroplasty

ARTICLE HIGHLIGHTS

Research background

There have been multiple recent studies indicating that adductor canal block (ACB) might be a safer option for patients undergoing total knee arthroplasty (TKA) procedure when compared to femoral nerve block (FNB) because of its potential ability to reduce patient falls, as it preserves quadriceps function while still effectively alleviating postoperative pain. Most studies, including a randomized control trial and a couple meta-analysis studies, have shown that patients who ACB have faster pain relief, greater quadriceps strength, and decreased hospital length of stay. There have been several studies comparing the fall rate between the two regional block techniques (FNB vs ACB), and all findings thus far have been equivocal. A lot of institutions have switched to ACB as their preferred regional analgesia simply based on preservation of quadriceps strength and early mobilization. Our institution made the switch to ACB as the primary regional analgesia after the occurrence of several patient falls following a TKA procedure using FNB. This study is significant and was done to evaluate the effectiveness of ACB at preventing falls at our institution and compare our fall rates to those reported in the literature.

Research motivation

The motivation behind this research is to evaluate and compare the fall rate after TKA procedure between ACB and FNB at our institution. This research is significant because it allows us to evaluate how effective ACB is at reducing patient falls after TKA when compared to FNB. Results from this study can be applied at various institutions to help decrease patient falls. Results from this study could also be a source of data points for future meta-analysis.

Research objectives

The main objective of this study was to evaluate and compare the fall rate after TKA procedure between ACB and FNB at our institution. Our results indicated that there was significant reduction in patient falls after TKA procedure after switching to ACB. This is important because our institution will continue to use ACB as the preferred regional analgesia for TKA procedure.

Research methods

In this study, we analyzed the fall data at our institution using our institutional quality improvement reporting database, Be-Safe from January 2013 to September 2016. We then accessed the electronic medical records for each patient that fell to confirm the procedure that was performed on the patient, the type of regional anesthesia received prior to the fall and the patient’s past medical history. We only included patients with the diagnosis of primary knee osteoarthritis who underwent primary unilateral TKA with either a FNB or ACB regional block and sustained a fall during their hospitalization. We excluded patients who had revision TKA, unicondylar knee replacements, history of total hip arthroplasty and extensor mechanism reconstruction. We then compared the fall rates in patients after receiving ACB vs FNB after a TKA procedure. We used the Fisher’s exact test to compare differences between the two groups, and there was a statistical significant difference between the groups (P < 0.006).

Research results

A total of 11 (1.3%) experienced a fall during their hospital stay after receiving FNB for a TKA procedure while one patient (0.13%) fell after receiving ACB for a TKA procedure. Results from this study indicated a significant drop in the fall rate at our institution after switching from FNB to the ACB. Our data indicate that patient and staff education on fall prevention and the use of ACB for patients undergoing TKA is effective at reducing falls.

Research conclusions

New findings in this study highlighted that there was an increased rate of patient falls after right TKA compared to left TKA. We also found that more female patients fell after TKA compared to male patients. We propose a new theory that due to extremity dominance, patients are more likely to fall after having a TKA procedure on their dominant lower extremity due to instability and weakness in their dominant/lead extremity. For unknown reasons, we also think that female patients are more likely to fall after TKA procedure when compared to male patients. We summarize that switching to ACB helped contribute to reducing the fall rate after TKA at our institution. We believe that the reduction in the fall rate is related to the preservation of the quadriceps strength with ACB as demonstrated by multiple prior studies[5]. We hypothesize that a systematic review or a case control study will help confirm our theory that female patients and patients that have TKA on their dominant extremity are more likely to fall when compared to male patients and patients that have TKA on their non-dominant extremity. There were no new methods proposed by this study. Our hypothesis that ACB reduces patient falls was confirmed in this study. Based on this study, our institution will continue to use ACB as the regional anesthesia for a TKA procedure. We will also continue to educate and take special precautions with patients that are high fall risk.

Research perspectives

This study helped highlight the importance of developing and maintaining patient safety initiatives in healthcare. It also helped in displaying the importance of patient and staff education and awareness to difficult safety issues in the hospital. The direction of future research will be to do a meta-analysis or retrospective study to further investigate if there is truly an increased risk in patient falls in females and after TKA on the dominant extremity. The best method for future research will be to perform a prospective study looking at the degree of quadriceps weakness, ambulatory distance, earlier or late ambulation, distance of ambulation during physical therapy, timed up and going test, and hospital length of stay post-operatively in male vs female patients and in dominant vs non-dominant extremity.