Lots of relevant research has consistently identified THA as a successful treatment for patients’ end-stage hip diseases [11]. Over time, the implementation process of DRGs-based payment has developed rapidly and LOS has become one of the most critical manifestations of health policies [12, 13]. Even though there has been rapid progress in THA surgery, there is little literature concerning factors that may affect LOS of THA patients. Peters et al believed that factors could be classified into two categories: patient characteristics and medical provider factors [14]. The concept of LOS was investigated quite intensively in recent years, but the reasons for extending LOS are currently unknown.
Although former researchers have spent much effort on shortening LOS and improving outcomes of THA. Unfortunately, most of the findings are varied and uncertain and they have not developed an efficient and effective method yet. Accurate data, regarding risk factors for prolonging LOS after THA, are critical for improving health outcomes. Efforts to reduce LOS and minimize adverse outcomes are necessary. Therefore, it is significant to explore the influence of the factors.
Reports from international registries revealed that extended LOS was independently associated with a history of comorbidities such as diabetes, heart disease, and hypertension, which were correlated with improved selected outcomes [15, 16]. Our findings are in consistent with earlier reports that comorbidity is one of the risk factors. For future patient care, multiple disciplinary discussions and more specifically perioperative evaluation are necessary for patients who were caught comorbidity if possible.
Previous papers demonstrated that several pre-operative variables were independently associated with extended LOS. Lower pre-operative Alb is one of the independent risk factors for predicting adverse outcomes following primary THA [17–19]. Our findings are in line with earlier reports and confirm the strong association between LOS and hypoalbuminemia (Alb < 30 g/L). Pre-operative Alb could promote incision healing and reflect the nutrition status, while hypoalbuminemia would lead to a variety of complications or even death. Malnutrition is a modifiable risk factor for poor outcomes and surgeons should pay close attention to patients’ nutrition status. Accurate identification of patients’ malnutrition will allow pre-operative nutrition interventions, which can help to improved post-operative outcomes.
Besides hypoalbuminemia, researchers demonstrated that abnormal pre-operative hematological tests are associated with prolonged LOS [20]. Lower pre-operative health status was associated with less satisfaction [21]. Our findings are in consistent with earlier reports and confirm the strong association between pre-operation CRP and LOS. CRP is a sensitive indicator predicting the probability of infection and inflammation. Laboratory evaluation could help surgeons identify and take appropriate preventive measures for high-risk patients. They can also help guide preparation pre-operatively and determine the intervention of routine follow-up post-operatively.
For patient characteristics, comorbidity is a non-modifiable risk factor but the status of nutrition and hematological results are modifiable. Devoting more attention to selected patients emphasizes the importance of considering comorbidities and preparing positive interventions in the context of the specific procedure.
Previous studies reported that surgical techniques could reduce adverse outcomes [22]. Acute nerve injury is rare but potentially devastating following THA due to the schedule of surgery[23]. Our results are consistent with earlier reports and confirm the strong associations linking LOS to date of surgery. These associations imply that schedule of operation is significant and crucial variables in improving outcomes. Surgical techniques and proper schedule are needed to be improved in order to perform surgery accurately.
Routine use of urinary catheterization in fast-track THA may increase the risk of postoperative urinary retention and infection, which are potential sources of infection [24]. These findings conflict against the routine use of perioperative indwelling catheterization [25, 26]. However, our results imply that catheterization is a risk factor and confirm the strong association between catheterization and LOS. Former research findings are debatable and further study may be needed. Patients treated with indwelling catheterization, history of urinary retention, and high volumes of fluid volume were significantly more likely to experience urinary retention and infection postoperatively. Intermittent catheterization, or removing it in the early stage, would be better choices for selected patients to prevent adverse outcomes if necessary.
Several papers have used administrative databases to evaluate drainage, which was associated with a prolonged LOS [27, 28]. Drainage could result into heterotopic ossification, which may result in more complications due to restriction of early postoperative mobilization and exercise [29, 30]. All of these findings are in line with our results and we indicate that drainage is a risk factor of prolonged LOS. Furthermore, no-drainage for easy THA may be a better choice for surgeons but complicated THA should be evaluated in details.
Based on the current finding, we can draw the conclusion that schedule of surgery, urinary catheter, and drainage can extend LOS for THA patients for parts of medical care providers. This knowledge not only can help physicians guide patients' expectations before THA but also direct surgeons devoting more attention to these factors in case of bringing negative effect.
Additionally, previous analysis demonstrated that extended LOS was independently associated with gender and age, and obesity [31, 32]. Some research believes that understanding current practice patterns in anesthesia may serve as a platform for future work aimed at maximizing effective postoperative pain control and minimizing the risks [33, 34]. The former research findings are not in line with ours but our data revealed the tendency about this, which may be due to the limitation of our dataset and the patient characteristics of our registration. We will consider increasing our sample size and performing a follow-up investigation in a future study.
Previous studies have emphasized potential advantages in reducing LOS. Evaluation of risk factors is beneficial in discussion of the perioperative risks of THA and patients' education in the different patient populations, and future studies should try to identify more precise factors. In order to shorten the LOS and improve THA outcomes, surgeons should pay more attention to selected patients during the perioperative management. Individualized treatment schedules and proper methods are needed to strengthen the intervention, which would be highly beneficial in shortening the LOS.
Furthermore, there are several limitations in our research study. First, we conducted this retrospective cohort study by using a database in our department several years ago, particularly with new generation constructs. Prospective studies are needed to validate these calculators and to refine them over time. Moreover, the standard of discharge may not be consistent according to the surgeon. Last but not least, the database did not include information on long-term follow-up outcomes. We believe that future studies are necessary to define the risk factors clearly and use more robust experimental designs to confirm the results.