Effect of enhanced recovery after surgery in the managements of ankle fracture patients: a single-center retrospective cohort study

Background Ankle fracture is common and the treatment is embarrassed. Enhanced Recovery After Surgery (ERAS) has been successfully adopted for the improvement of ecacy and quality. However, application of ERAS in ankle fracture patients especially at the early stage is variable and remains to be claried. We intent to explore the effect of ERAS among ankle fracture patients. There were 29 male and 51 female patients aged 41.71 ± 14. 51 years who were consecutively grouped into non-ERAS group (n = 40) and ERAS group (n = 40). Univariate analysis and multiple linear regression analysis were applied to assess the association in outcomes and variables. the perioperative management, which is good for accelerate rehabilitation. Multiple linear regression analysis reveals that PO3M and PO6M AOFAS were veried between the two groups (p<0.05). ERAS protocol can improve the outcomes in terms of short-term rehabilitation and we believe that patients will have favorable outcomes when treated by all of these subspecialty providers. but more evidence is needed to demonstrate during clinical practice. Patients would be evaluated after surgery and opioids will be prescribed if VAS ≥ 6. The overall consumption of opioids are similar between two groups in univariate analysis (OR: 0.603, p>0.05, 95% CI, 0.223 to1.630). Moreover, we notice that the number of patients is smaller in ERAS group. Multi-modal analgesia strategies were adopted in ERAS group which may help to improve positive outcomes with better experience and satisfaction. With the direction of ERAS in perioperative plan, we believe ankle fracture patients would benet more.


Introduction
The ankle joint is the largest weight-bearing joint in human body and the fracture is the most common intra-articular fracture [1]. The rate of ankle fracture increased with the development of aging society, sports activities, or even widely use of cell phones, which often causes a high disabled rate and increases the economic burden of the family and society [2,3]. The managements of ankle fracture at the time of operation remains one of the most challenging tasks for orthopedists because of special anatomic. ERAS was rstly proposed by Kehlet, which can decrease complications, shorten the LOS, and improve patients' satisfaction [4]. ERAS has been successfully adopted across a range of diseases, which was performed well in the improvement of outcomes at the early stage [5,6]. There lacks high-quality literature investigating the managements of ankle fracture patients with the application of ERAS in the early post-operative stage. Diagnosis-related groups (DRGs) payment have a signi cant impact on the hospital market. The indicator LOS is used to gain insight into quality and safety of medical care, which is one of the most crucial manifestations of DRGs [7]. Patient socioeconomic status appears to be associated with LOS and costs, which suggests ankle fracture patients may require reform to improve quality and e cacy.
Previous study implies that ERAS application for trauma injury is effective but without standard process, moreover, the assumed advantages of ERAS for ankle fracture patients have not been su ciently studied. Ankle fracture treatment may be complicated by postoperative pain, increased LOS, higher costs, and decreased patient satisfaction. Studies are needed to investigate effect of ERAS protocol on its short-term clinical outcomes, and therefore, we launched this study to explore the impact of the ERAS at the early stage in ankle fracture patients based on preliminary experience and evidence-based medicine (EBM).

Patients
The study was carried out in our hospital located in south of China between January and May in 2018 . Patients who refuse to be   admitted into the study, caught open fractures, with sever comorbidities, undergone previous surgery on the injured ankle, younger  than 14-year old, loss of follow-up, or information missed were excluded. During the study period, 114 ankle fracture patients were   treated and 34 cases were excluded, 6 cases for not meeting inclusion criteria, 9 cases for not giving consent, and 19 cases for loss of follow-up or information missed. We included ankle fracture patients who met inclusion and exclusion criteria (Fig. 1). All enrolled patients were invited for a clinical and radiological follow-up and the mean period was 24 months. All of the surgeries were conducted by the same experienced and skilled surgeon.

Variables
We reviewed discharged abstract that involved a multitude of variables and data was obtained from medical electronic records system retrospectively. Patient characteristics including age, gender, diagnosis, Lauge-Hansen (LH) classi cation, Danis-Weber (DW) classi cation, ankle joint dislocation or not, medial malleolar injury (fracture or ligment rupture), operative date, and comorbidities (hypertension; diabetes metabolism (DM); coronary heart disease (CHD), stroke, and others).
To con rm outcomes reported noted in the literatures, we identi ed patient-reported outcome measures (PROMs). The outcomes including AOFAS at PO3M, PO6M, PO12M, and PO24M. we also included costs, total LOS, pre-operative LOS, post-operative LOS, the occurrence of post-operative complications, and opioids consumption in the rst 24-hour. LOS (in days) were de ned as the number of days from admission to discharge. The investigation of the outcomes was performed carefully to ensure the validity of the study.

Application of ERAS
ERAS would take account into the patients' conditions and individual differences, which require the multi-disciplinary team (MDT) work. Our group developed the relevant pathway for patients according to the consensus guideline by means of improving the knowledge, popularizing the proper understanding effect, and standardizing the process (Fig. 2).

Discharge criteria
Previous studies emphasize the discharge criteria for ankle fracture patients varies worldwide [8]. The discharge criteria for ankle fracture patients in our department are the followings when clinically appropriate. (1) Patients who are willing to be discharged, (2) patient signs such as appetite and sleep are normal and stable, (3) incision heals well without any symptoms of infection, (4) hematological results are normal, (5) visual analogue scale (VAS) ≤ 3.

Statistics analysis
Outcomes are respectively summarized by descriptive statistics. Continuous variables were summarized using mean ± standard deviation (SD) while categorical variables were summarized using number and percentage. Univariate analysis was used to analyze the relationships of the variables and multiple linear regression analysis was performed to examine the effects of signi cant variables on the outcomes. Paired two-sided t test if samples conformed to the normal distribution while Mann-Whitney U test for no normality of distribution of the continuous variables. We used the Chi-square test in cases with all expected values greater than ve, otherwise we used the two-sided Fisher's exact test for category variables. All statistical analysis was performed on SPSS Statistics (IBM version 25.0) and R (version 4.0.2). p < 0.05 were considered statistically signi cant and p < 0.001 were considered statistically highly signi cant. We also reported 95% con dence interval (CI) for each parameter estimate.

Results
The patients who were diagnosed ankle fracture underwent open reduction and internal xation (ORIF) were consecutively grouped into the Non-ERAS (n = 40) and ERAS (n = 40) care pathway. 80 patients were ultimately included in the present study. There were 29 males and 51 females with an average of 41.71 ± 14. 51 years. All participants were followed up around 24 months (22.6 months ~ 27.2 months) and we evaluate patients' rehabilitation by AOFAS at PO3M, PO6M, PO12M, and PO24M. With the numbers available, no signi cant (p>0.05) difference was observed among patient demographic variables (Table 1). were veri ed between the two groups (p<0.05). With the numbers available, no signi cant differences were observed for PO12M AOFAS (95% CI, -0.931 to 0.682), PO24M AOFAS (95% CI, -1.132 to 0.332), complications, and opioids consumption between the two groups (p>0.05) ( Table 2).   (Table 3).

Discussion
Represented in the medical literature, Ankle fractures are one of the most common skeletal injuries and accounting for approximately 7-10% of emergency department (ED) visits [9]. Traumatic injury of the ankle constitute almost 40% of all sports injuries, which can result in long-term disability and cause substantial negative implication on patient's functional recovery [10]. The appropriate diagnosis and managements of the challenging injuries still remains controversial. Moreover, rapid and large-scale implementation of ERAS program is feasible and effective [11]. Patient-center approach to optimize patients care and experience during the perioperative period, which has been shown to be effective in improving outcomes [12,13].
Present studies con rmed that standardized ERAS protocols can optimize the outcome of ankle fracture patients. As the major principle of treatment remains to achieve an anatomic reduction and a stable xation, precise preoperative diagnostics and treatment planning are of great importance. Available literature revealed that combined injuries are common among ankle fracture patients which can result in signi cant adverse effect. Stenquist et al suggest that patients with any medial tenderness were at signi cantly higher risk of unstable ankle fracture with instability [14]. Casting or orthosis application non-inferior to cast immobilization is recommended for stable ankle fractures [15][16][17][18]. Naumann et al suggested that 6 days would be a safe window for operation that can be used to plan and perform the nal operation [19]. While ORIF is an optional strategy for unstable ankle fractures, syndesmosis and deltoid ligament repair may promote fracture union and allows patients to start earlier weight-bearing [20,21]. Some of the patients accompanied with several combined injuries or dislocation, fortunately, all of them were treated properly and gain satis ed outcomes of rehabilitation.
AOFAS is a powerful tool to evaluate ankle disorders' function and rehabilitation [22]. We evaluated PROMs by AOFAS at different point after operation at PO3M, PO6M, PO12M, and PO24M. Signi cant difference of outcomes at PO3M and PO6M were veri ed.
With the numbers available, no signi cant differences were observed (p>0.05) at PO12M and PO24M were veri ed between the two groups. However, we notice that better prognosis and tendency in ERAS group in the PO12M. Orthopedic surgeons and rehabilitation physicians often in conjunction together to manage patients with fractures [23]. Some of the researchers believed that special designed devices shown advantages to reduce adverse events and accelerate rehabilitation [24,25]. One of the signi cant methods in ERAS is to make proper procedure that including reduction and temporary xation under emergency anesthesia after the careful evaluation in ED. Patients would obtain early mobility and pain relief through the perioperative management, which is good for accelerate rehabilitation. Multiple linear regression analysis reveals that PO3M and PO6M AOFAS were veri ed between the two groups (p<0.05). ERAS protocol can improve the outcomes in terms of short-term rehabilitation and we believe that patients will have favorable outcomes when treated by all of these subspecialty providers.
Previous analysis demonstrated that demographic characteristics and procedures may affect the coats and LOS of ankle fracture patients, which has important clinical and economic implications, providing a target for improving patient outcomes [26,27]. Signi cant different outcomes were veri ed (p<0.05) including costs and LOS are associated with ERAS in both univariate analysis and multiple linear regression analysis, which are in line with previous study and con rm the advantages of the ERAS. The nding application of ERAS can reduce the costs and LOS may assist staff and patients pay more attention to the application of ERAS during clinical practice. DRGs payment system was introduced and mandated worldwide for its potential to curbing unnecessary resource and cost-saving implications by decreasing costs and LOS [28,29]. Relevant literatures re ected that healthcare system assess satisfaction and quality of the inpatients, which highlights the speci cation of ERAS [30,31]. Efforts to improve the healthcare should be focused on implementation and enlargement of the DRGs and ERAS.
Traumatic injuries are particularly challenging when they associate skin and soft tissue frail. Perioperative complications are challenges and unsolved problems, underlining the need for further research. In view of frequent recommendations and reports, ERAS protocol has been applicated for many diseases without increasing rate of adverse outcomes [32,33]. Among all of the patients, no complication was observed in ERAS group. No case caught complication in ERAS group. Two cases in non-ERAS group developed into super cial incision infection and urinary tract infection but were cured with proper procedure. The characteristic of the old, comorbidity, and obesity are more likely to caught complications [34,35]. Bene t of ERAS application prevent complication is not statistic signi cant but there exists a tendency in univariate analysis (OR: 0.950, p>0.05, 95% CI, 0.885 to 1.020), which may be limited for small sample.
Ankle fracture can cause post-operative pain but literature is scarce in evaluating opioids consumption in the rst 24-hour. Previous study suggested that patients with opioid-related adverse events have greater higher risk of costs and ED visits [36,37]. By understanding the impact of potential side effect of opioids, we intend to introduce perioperative pain managements but more evidence is needed to demonstrate during clinical practice. Patients would be evaluated after surgery and opioids will be prescribed if VAS ≥ 6. The overall consumption of opioids are similar between two groups in univariate analysis (OR: 0.603, p>0.05, 95% CI, 0.223 to1.630). Moreover, we notice that the number of patients is smaller in ERAS group. Multi-modal analgesia strategies were adopted in ERAS group which may help to improve positive outcomes with better experience and satisfaction. With the direction of ERAS in perioperative plan, we believe ankle fracture patients would bene t more.
Our study has some strengths. To our knowledge, it is the rst investigation to con rm the advantages of EARS application among the proper ankle fracture patients at different point after operation. The comprehensive data allowed us to examine the bene ts of the ERAS protocol which can improve rehabilitation, quality and e ciency at the early stage. Furthermore, some limitations of the present study should be addressed before making a conclusion. First, the investigation was a retrospective cohort study which is associated with inherent selection bias. Second, we conducted the study with a single-center small database, multiply center giant samples and prospective protocols are needed for further study. Third, the standard of discharge may not be in consistent, which require standard discharge criteria among hospitals. Last but not least, the database did not include information on long-term follow-up outcomes. We believe that prospective studies with long-term follow-up are essential to de ne the machination clearly and more robust experimental designs are needed to validate the conclusions over time.

Conclusion
To make a conclusion, our study explores and illustrates the effect of ERAS can enhance the short-term rehabilitation especially at the early stage. We found ERAS can also improve quality and e ciency of health care by reducing costs and LOS among proper ankle fracture patients. ERAS has a promising future and worth promoting.