Abstract

Introduction
The volume of total joint arthroplasty (TJA) performed in the outpatient setting has substantially increased; indeed, ambulatory surgery center (ASC) arthroplasty volume is predicted to increase substantially in the next 10 years [12,15]. Advantages to outpatient TJA include increased patient satisfaction, reduced complication rates, reduced risk for nosocomial infection, and avoidance of unnecessary tests. Outpatient TJA also leads to improved proficiency and morale among the surgical team and reduced health care spending; it also allows for a more personalized experience between the surgeon and patient, who can interact unimpeded by hospital policy [24,35]. Multiple studies have demonstrated the safety and efficacy of same-day discharge (SDD) in both primary TJA and in select revision cases [6]. However, successful outpatient TJA requires thorough medical evaluation, risk assessment, and optimization [2,12,14,25,40,43,44,56,67]. Optimized and controlled medical comorbidities do not guarantee safe outpatient TJA. This article will discuss tools to improve patient safety in the perioperative period, beginning with preoperative education, then addressing the most common comorbidities and causes of early readmission or emergency room visits and the barriers to SDD.
The Importance of Preoperative Education
Traditional arthroplasty “joint classes” have demonstrated efficacy in improving outcomes by decreasing anxiety and pain, as well as by improving coping and reducing both readmission rates and health care spending [11,31,46,47]. In fact, this is the foundation of patient education in successful outpatient TJA, especially because providers have less time than in the inpatient setting to educate, diagnose, and treat potential perioperative events related to anesthesia, surgery, and/or host disease. Consequently, patients and caregivers must be prepared for a variable postoperative course at home, without the aid of round-the-clock medical staff for managing pain, nausea, vomiting, swelling, and other symptoms that may occur for the first time at home. These issues are not unique to patients with medical comorbidities, and by discussing them early and often, by being proactive rather than reactive, outpatient TJA can be consistently safe and successful. The 4 elements of inpatient total joint discharge are applied and augmented: preoperative education, discharge instructions, staff availability, and creation of a safety net in the case of unexpected medical events [10].
The primary goal of education is to give patients and caregivers the confidence to manage their own health care needs. This is especially important in patients with multiple comorbidities, who must understand that education will improve their expectations [48], clarify that taking an active role in their own care is a major factor in achieving desired outcomes. Preoperative education also provides patients with clear rehabilitation goals and expectations for the recovery process. Individuals undergoing arthroplasty have high expectations for their outcome, and the strongest predictor for dissatisfaction is not having expectations met [53,66]. Improving alignment of expectations and ensuring patient understanding will improve satisfaction and, importantly, prevent unnecessary readmissions postoperatively.
Many surgeons limit their outpatient arthroplasty practice to their healthiest patients. Many patients with end-stage arthritis also have multiple medical comorbidities [51], and outpatient TJA can still be achieved in patients with well-controlled medical comorbidities. This starts with patients understanding and taking responsibility for their health. It does not start with physicians not limiting their practice to healthy patients.
Outpatient TJA in the Patient With Comorbidities
Identifying comorbid medical conditions is the first step in safe outpatient TJA. Adequate outpatient surgical selection requires the identification of patients for safe SDD and have minimal risk of early readmissions or emergency room visits. It is critical to note that this differs from identifying patients who have risk factors for postoperative medical and/or surgical complications within 30 or 90 days. These later complications have been the traditional focus of study and, while still important, they are distinct from causes of SDD failure. A multidisciplinary, team-based approach has been the most effective strategy in risk assessment and stratification. Once comorbidities have been identified, perioperative optimization can take place to safely perform surgery and minimize the common and uncommon barriers to successful outpatient TJA.
Risk factors that impede SDD can be categorized as modifiable or nonmodifiable. Nonmodifiable risk factors are important to recognize but are beyond the control of the surgeon and patient. Some have suggested end-organ failure as the only true medical contraindication to elective outpatient arthroplasty [13]. While this group of surgeons has safely performed thousands of outpatient joint replacement surgeries, the reader should consider the possibility that selection bias in the studied patient population may not lead to translatable results across all patients and institutions.
Patient selection for outpatient TJA begins with a medical evaluation consisting of a complete history and physical examination—the importance of this cannot be overstated. Laboratory and cardiac testing should be obtained based upon current perioperative guidelines. Risk assessment tools can be used, but a limitation is that most of them provide data on medical risk or risk of 90-day postoperative medical complication, which do not translate directly into eligibility for outpatient TJA. The most used classification system to risk stratify surgical patients is the American Society of Anesthesiologists Physical Status (ASA-PS) classification. The ASA-PS score is based on a I-to-V scale. A score of I represents the “normal healthy patient”; II is a patient with “mild systemic disease”; III is a patient with “severe systemic disease”; IV is a patient who has a severe systemic disease which is “a constant threat to life”; and V is the “moribund patient not expected to survive without operation.” The ASA-PS classification leaves most patients with scores of I to III eligible for elective TJA. However, the lack of detail and scientific precision in this system makes it a poor outpatient selection tool for TJA [55]. The Charlson comorbidity index (CCI) is a risk calculator that predicts 10-year mortality in patients with multiple comorbidities. Accepted for general medical use, it has been used as a surrogate risk calculator for patients undergoing outpatient TJA but has not been validated in screening patients for this indication [8,54].
It is difficult to ascertain whether medical risk factors/comorbidities result in a higher likelihood of, or overt failure of, SDD. The Outpatient Arthroplasty Risk Assessment (OARA) is a proprietary risk stratification tool designed specifically for predicting a patient’s ability to safely SDD following TJA [52,72]. The OARA considers several comorbidities, allowing for validated decision-making in determining candidacy for outpatient TJA with more reliability than either the ASA-PS or the CCI. Developed at a single institution, this tool was the result of a collaboration between a perioperative internal medicine physician who has worked with more than 20,000 arthroplasty patients over the last 2 decades and a high-volume arthroplasty surgeon with over a decade of experience with rapid recovery and early discharge protocols. In addition, the OARA scoring system has been validated externally for early discharge in primary total hip arthroplasty (THA) [39]. The OARA score comprises 9 comorbidity areas, each containing specific medical conditions. The comorbidity areas include general, hematologic, cardiac, endocrine, gastrointestinal, neurologic/psychologic, renal/urologic, pulmonary, and infectious disease.
The OARA score has shown positive predictive values of 91.5 and 98.8 at a single institution for determining which patients are safe for early discharge in the ambulatory setting. It has also been externally validated outside of the original institution with a positive predictive value of 86.1 for rapid discharge in THA patients. Compared with existing medical risk stratification tools, such as ASA and CCI, the OARA score provides more scientific precision; current, conservative data have determined that scores between 0 and 79 (maximum 100) are highly effective in determining which patients can safely undergo SDD following TJA [39,52,72].
The logistics of the OARA score for outpatient arthroplasty selection begins with a general assessment of physical function and home support systems. This is generally performed by a perioperative medical specialist who asks the patients a series of questions and uploads answers into the proprietary software system. All primary TJA patients at our institution undergo this process to determine their OARA score. In determining a patient’s readiness for SDD, a few comorbid conditions are particularly important. First, preoperative narcotic use, though not prohibitive to outpatient arthroplasty, can lead to substantially increased postoperative pain. Consequently, it is important to emphasize preoperative planning with the patient’s opioid prescriber and to pay attention to multimodal pain control preoperatively, intraoperatively, and postoperatively. As well, dementia and other neurologic diseases can increase the complexity of rehabilitation and postoperative pain control. These conditions also heighten the risk of delirium from anesthetics and opioids. Consequently, patients with these conditions require a coach or family member who prepares with the patient and clearly understands what to expect in the early postoperative period. Cardiac patients with stable coronary artery disease are appropriate candidates for outpatient TJA. Patients eligible for SDD, but who remained overnight, were not found to have an elevated risk of cardiac events or interventions for cardiac monitoring, including patients with a history of preexisting cardiac conditions [42]. However, patients with more unstable cardiopulmonary disease or obstructive pathology such as aortic stenosis should have these conditions preoperatively optimized. In rare instances where the patient is deemed optimized for surgery but requires more extensive postoperative monitoring, an overnight stay may be required and should be discussed with the multidisciplinary team. Pulmonary disease can be further exacerbated by perioperative opioid administration; thus, pathologies such as obstructive sleep apnea (OSA) are important to recognize and incorporate into risk assessment. Severe chronic obstructive pulmonary disease or asthma should also be considered and optimized preoperatively. Hematologic evaluation includes assessment for preoperative anemia with the primary goal of avoiding postoperative transfusion or cardiac demand ischemia. Coagulopathic disease requires careful attention to medications to balance postoperative thromboembolic disease and an increased risk of wound complications. In these instances, the shared decision-making of the multidisciplinary team, in collaboration with the patient and their family, is important but not preclusive of safe SDD.
Uncontrolled diabetes mellitus not only increases perioperative risk but also demonstrates poor long-term patient compliance. This may translate into poor short-term patient compliance and increased risk of 48-hour readmission. Thus, patients with inadequately optimized glycemic control should be delayed until better control is demonstrated. Patients with end-stage cirrhotic liver disease are also considered high risk for acute decompensation postoperatively; in general, these patients should be comanaged in a hospital setting if elective arthroplasty is offered. Patients with chronic kidney disease frequently have concomitant electrolyte imbalance as well as high sensitivity to fluid shifts. Care should be taken perioperatively to minimize acute renal injuries and periods of significant and sustained hypotension, which can further exacerbate renal disease. Generally, appropriate fluid balance with the anesthesiologist and avoidance of nonsteroidal anti-inflammatories is required to safely allow for SDD.
Perhaps the largest unsolved hurdle in SDD TJA is postoperative urinary retention (POUR). Identifying patients with risk factors including a history of benign prostatic hyperplasia and a history of POUR can be helpful in planning. For example, the prophylactic use of alpha-adrenergic blockers, scheduling these patients early in the day to allow time to void, appropriately titrating fluids, and avoiding medications that increase POUR risk are all important [1,4,73]. Even the best laid plans may fail to result in successful urination, in which case, overnight stay, self-directed in-out catheterization, or Foley catheter placement with urology follow-up are all acceptable options.
Other modifiable risk factors including malnutrition, smoking, vitamin D deficiency, Staphylococcus aureus colonization, and inflammatory arthropathy should be optimized prior to elective TJA, whether inpatient or outpatient.
Diabetes mellitus is known to increase the risk of both surgical site infection (SSI) and prosthetic joint infection (PJI). The percentage of glycosylated hemoglobin (HbA1C) provides information regarding glycemic control over a 3-month period and can be obtained with a simple laboratory blood test. An HbA1C of less than or equal to 7.5% to 8.0% reflects adequate mid-term to long-term glucose control; for patients above this threshold, we recommend delaying elective arthroplasty, regardless of the surgical setting. Perioperative blood glucose levels reflect short-term glycemic control and can also be used as markers perioperatively. Preoperative glucose levels are especially useful because intraoperative use of dexamethasone for analgesia and nausea/vomiting may alter postoperative glucose levels. If patients demonstrate acceptable glycemic control preoperatively, the surgical setting should not be changed simply to monitor a patient’s glucose in an inpatient setting. Rather, patients at higher risk for nosocomial complications should be returned to an environment with which they are familiar to avoid unnecessary testing and interventions [21,30,37,49,64].
Similarly, obesity may increase perioperative risk. This is, in part, due to the thickness and depth of adipose tissue, which increases time for surgical exposure in arthroplasty, and therefore increases the risk of PJI. Limited vascularity to the adipose soft tissue can also contribute to higher rates of wound complications in obese patients [69,74]. Understanding the unique risks of obesity in the perioperative period is crucial, but should not restrict access to arthroplasty if otherwise indicated and the patient is fully informed of the risks, as we know patients with obesity can expect similar improvements in pain and function as do nonobese patients with TJA [70]. Oftentimes, patients with obesity have undiagnosed OSA; to ensure safety when receiving pain medications in an unobserved setting at home, OSA should be identified preoperatively and optimized prior to surgery.
Obesity occurs when caloric intake exceeds caloric expenditure, but it is important to be aware that high calorie diets can often be nutritionally poor. When evaluating the role of malnutrition in TJA patients, it was found that more than 40% of obese patients are malnourished, defined by total lymphocyte count <1500 cells/mm3, serum albumin <3.5 g/dL, or transferrin <200 mg/dL [28]. Preoperatively optimizing nutrition is crucial to improve wound healing and reduce the risk of complications. However, nutritional status should not be used to exclude patients from outpatient arthroplasty—instead, the multidisciplinary team should work to optimize these variables preoperatively to assure safe SDD.
Smokers who undergo both primary and revision TJA are known to be at higher risk for all-cause revision, faster time to revision, complications, and PJI [3,17,33,58,62,63,65]. The successful completion of a smoking cessation program may decrease these complications—even with as little time as 4 weeks preoperatively. Prior to elective TJA, we recommend smoke-free for a minimum of 4 weeks. If there is concern for patient noncompliance, multiple tests including a serum cotinine (nicotine metabolite) assay can be performed to confirm nicotine abstinence. After optimization, prior smoking history should not preclude a patient for outpatient arthroplasty, but current smoking status should delay elective surgery until abstinence is assured.
Nasal decolonization of S aureus significantly lowers postoperative SSIs. Universal decolonization via twice daily mupirocin ointment in the nares along with daily chlorhexidine bath for 5 days preoperatively has been demonstrated to reduce infection risk in arthroplasty patients [9,57]. In addition, patients who are positive via polymerase chain reaction testing for methicillin-resistant Staphylococcus aureus (MRSA) receive a preoperative dose of vancomycin as well as standard antimicrobial prophylaxis [38,59]. Preoperative colonization with S aureus should not impact the choice of the site of surgery.
The presence of inflammatory arthropathy is another modifiable risk factor for TJA patients. Studies suggest a correlation between inflammatory arthritis and PJI. Immunomodulator drugs may impair wound healing and substantially increase risk of PJI. Joint clinical practice guidelines between the American College of Rheumatology and the American Association of Hip and Knee Surgeons (AAHKS) recommend continuation of traditional disease-modifying antirheumatic drugs; however, immunomodulators should be withheld by 1 dose cycle prior to undergoing elective TJA [22,41]. If appropriately managed and stable, patients with a diagnosis of inflammatory arthritis should not be withheld from the opportunity for SDD.
It is well established that routine intravenous antimicrobial prophylaxis is effective in reducing SSIs and can help mitigate risk factors in a patient with an increased infection risk. First-line agents include weight-based dosing of a first-generation cephalosporin; non-cephalosporin prophylaxis has been shown to increase SSIs [71]. Patient-reported beta-lactam allergies can be confirmed with preoperative allergy testing. In those cases, we recommend clindamycin or vancomycin prophylaxis. In general, however, patients should receive cephalosporin antibiosis if possible. Cephalosporin and clindamycin should be administered within 1 hour of incision and vancomycin within 2 hours to achieve efficacious tissue doses. A single dose of vancomycin can be considered in addition to standard prophylaxis in patients with MRSA nares colonization [18]. Wound complications and PJI risk can be further reduced by extended oral antimicrobial prophylaxis and negative-pressure wound therapy in high-risk patients [16,26,36].
Other Important Considerations
While the best anesthesia for primary TJA has yet to be established, multiple studies demonstrate advantages of spinal anesthesia, including decreased blood loss, decreased nausea and vomiting, decreased length of stay, decreased deep vein thrombosis, increased oxygenation, and even potentially decreased infection rates [32,50]. Important factors to consider include a safe primary anesthetic in a patient with optimized physical status, multimodal pain control, rapid return to awake state, and the ability to perform physical therapy (PT) in a timely fashion. Regional nerve blockage, periarticular infiltration, and multimodal oral analgesia/antiemetic regimens facilitate safe SDD. In addition, enhanced recovery after surgery protocols aid to maximize postoperative recovery [68].
Additional factors that affect successful outpatient TJA include fluid management/resuscitation, multimodal pain control, minimizing blood loss, infection prevention, and incisional management. Fluid management emphasizes euvolemia to avoid hypertension and minimize POUR. Many protocols allow patients to drink clear fluids for up to 2 hours before surgery and administer approximately 2 L of intravenous fluids intraoperatively to maintain fluid balance/tissue perfusion [73]. Multimodal pain control incorporates both preoperative and postoperative medication administration in addition to neuraxial anesthesia, regional nerve blockage, and periarticular injections in TKA. Finally, transfusion rates have significantly decreased, even in the comorbid patient, due to preoperative optimization, less invasive soft tissue dissection, modern surgical approaches, hypotensive anesthesia, and routine use of tranexamic acid (TXA). Guidelines from the AAHKS, American Society of Regional Anesthesia and Pain Medicine, American Academy of Orthopaedic Surgeons, The Hip Society, and The Knee Society all recommended routine TXA administration to reduce blood loss and subsequent rates of transfusion [19,34]. This is a critical component of outpatient TJA, as high rates of transfusion historically had mandated inpatient admission for postoperative observation.
All of these components are part of a larger system working harmoniously to combat the established barriers that preclude patients from SDD or next-day discharge—dizziness or hypotension, pain control, POUR, nausea/vomiting, and in some instances, patient preference [5,20,27,45,61,73]. A proactive approach to prevent these barriers to discharge via preoperative optimization, stratification, education, and reassurance is by far the most critical component for success.
Medical complications may occur that are prohibitive to SDD. Multimodal care coordination with anesthesiology and internal medicine can mitigate these events and allow for discharge within 24 hours, often following overnight inpatient admission/observation. For the patients who may be at higher risk for these events, the 2 major options for performing outpatient TJA are either freestanding ASC or in the hospital outpatient department (HOPD) of a full-service hospital. Hospital outpatient departments are typically owned by the hospital and often physically attached to a full-service hospital. Retrospective studies with early data have shown no significant difference in outcomes, readmission rates, or complications, though careful preoperative patient selection is a component that undoubtedly adds selection bias to these results [35,60]. Small, randomized trials conducted in Denmark showed that in patients with planned SDD, those who underwent TJA and stayed in the ASC postoperatively were more likely to discharge home on the day of surgery compared with those who stayed in the inpatient ward postoperatively. This differs slightly from a true HOPD setting but may demonstrate a psychologic phenomenon with patients exhibiting lower comfort for SDD in the hospital setting [29]. The advantage of same-day surgery in the HOPD is that it provides a safety net for overnight admission in patients who fail to meet criteria for safe SDD [23]. Further research is required, with patient safety paramount in the consideration.
In conclusion, rapid discharge surgery is on its way to becoming a standard of care in multiple patient populations, including those with stable comorbid medical conditions who undergo prescreening and optimization [7,51]. Successful outpatient TJA in the comorbid patient requires thorough preoperative evaluation and risk assessment. Several medical risk stratification calculators are available, but only the OARA is designed specifically to screen for patients that meet criteria for rapid SDD following TJA. This evidence-based approach to patient selection along with standardized perioperative protocols, protocolized postoperative management, and a safety net in the rare instance of postoperative complications are the critical components to a successful outpatient TJA program. By using appropriate medical evaluation and validated tools to identify risks for failure, the goal is to make safe, evidence-driven, outpatient TJA a feasible option for a much larger pool of patients, including those with medical comorbidities and risk factors [52,72].
Supplemental Material
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Supplemental material, sj-docx-1-hss-10.1177_15563316231208431 for Outpatient Hip and Knee Arthroplasty Can be Safe in Patients With Multiple Medical Comorbidities via Use of Evidence-Based Perioperative Protocols by Sohum Patel and Leonard T. Buller in HSS Journal®
Supplemental Material
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Supplemental material, sj-docx-2-hss-10.1177_15563316231208431 for Outpatient Hip and Knee Arthroplasty Can be Safe in Patients With Multiple Medical Comorbidities via Use of Evidence-Based Perioperative Protocols by Sohum Patel and Leonard T. Buller in HSS Journal®
Footnotes
Declaration of Conflicting Interest
The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: Sohum Patel declared no potential conflicts of interest. Leonard T. Buller reports relationships with Enovis, Osteoremedies, and Link Biomedical.
Funding
The author(s) received no financial support for the research, authorship, and/or publication of this article.
Human/Animal Rights
All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1975, as revised in 2013.
Informed Consent
Informed consent was not required for this commentary.
Level of Evidence
Level V
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References
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