As techniques and design of total knee arthroplasty (TKA) have been refined over the years, postoperative patient care practices too have evolved dramatically. Historically, patients were admitted for 7 to 10 days after TKA.¹ The first night was spent in a mini-intensive care unit and strict bed rest was observed. Knees were immobilized and wrapped in bulky Jones dressings, and patients would finally be allowed to stand on postoperative day 2 or 3. With the advent of in-hospital skilled nursing facilities (SNFs), patients soon would spend the latter 5 to 7 days of their stay in these units. Then, as less-invasive surgical techniques began to emerge, the status quo of patient recovery began to be challenged. Rapid recovery protocols quickly took hold, and the average length of stay (LOS) has since been declining. Now, it is common for patients to stay 1 or 2 nights after a TKA procedure with full weight-bearing the day of surgery and discharge to home. The next frontier that has increasingly been adopted is outpatient TKA.

While the move to outpatient TKA is in keeping with the ultimate goal for elective surgery to provide patients with consistently excellent results and the best possible experience, it is also motivated by pressure for cost reduction, particularly in light of escalating demand for the procedure.² This drive to reduce costs by eliminating inpatient admissions has to be balanced by the potential increase in postoperative complications and readmissions. Traditionally, patients have required inpatient admission due to concerns for postoperative pain and decreased mobility. However, with improved postoperative protocols, these challenges can and have been addressed. This chapter discusses these specific challenges and the pathways that have been developed to make outpatient TKA a reality.

Outpatient TKA truly can be performed in any setting, from a large tertiary referral hospital to a stand-alone ambulatory surgery center (ASC). There are advantages and disadvantages to either setting. In the hospital setting, there is a safety net of medical consultants and intensive care unit (ICU) resources should a complication arise. Additionally, larger hospitals may have greater access to a broad inventory of implants and instrumentation that a smaller facility may not readily carry. Perhaps one of the biggest disadvantages to a larger facility is the surgeon’s lack of direct management of perioperative staff. The surgeon often must work with hospital administration to enact changes, which may prove challenging and obstructive. In an ASC or even in some specialty-specific hospitals, the surgeon is likely to have more input in making changes necessary to improve efficiency and enact outpatient protocols.

What is more important than the actual facility is the culture of the staff. To perform outpatient TKA safely requires more than the surgeon simply deciding to discharge his or her patients on same day as surgery. It requires an entire team to be on the same page and to have the vision of rapid recovery and safe, early discharge to home. The surgeon needs buy-in from nursing, anesthesiology, physical therapy, and administration in order to accomplish the goal of same-day discharge. This is not a transition done overnight. It often requires a gradual reduction of length of stay until the average stay is one overnight. Then certain patients may be selected for same-day discharge. This practice allows a gradual assimilation of perioperative staff to the culture of outpatient TKA and permits the surgeon and others to safely identify and address challenges along the way without significant disruption to the overall mission.

Our experience has mirrored the above pathway of gradual transition. The authors of this chapter developed a musculoskeletal specialty hospital where a rapid recovery pathway was implemented. With direct oversight of staff and the execution of this protocol, length of stay was gradually reduced to an average of 1.5 days. The transition was then made to same-day discharge, which influenced the development of a separate ASC following the same rapid recovery clinical pathway.

All patients presenting for TKA may be considered as candidates for outpatient surgery. As rapid recovery protocols and medical optimization improve, what was once an option only for healthy, highly motivated patients is now being offered to mainstream patients. Still, care must be exercised to ensure that patients are medically optimized and that key comorbidities are identified. This
begins with the patient’s initial visit to the surgeon’s clinic. A brief survey of the patient’s medical history may be all that is necessary to preclude a patient from outpatient surgery. The outpatient TKA candidate must have appropriate medical insurance. While age is not an independent contraindication for outpatient TKA, most patients aged 65 years and older have their insurance through Medicare, which did not support outpatient TKA in the ASC prior to January 1, 2020.

The preoperative medical evaluation is another important step in this process. This involves a comprehensive history and physical, appropriate laboratory and/or other testing, and referral to a medical specialist if needed. Meding et al observed that preoperative medical evaluations for elective total joint arthroplasty (TJA) procedures identified a substantial number of new diagnoses, and that 2.5% of patients were considered unacceptable surgical candidates as a result of these visits.³ In addition, general medical specialists can provide medication reconciliation along with instructions on which medications to discontinue prior to surgery as well as the proper dosing of other medications on the day of surgery.

There is a difference in opinion as to what if any firm selection and exclusion criteria should be established for outpatient TKA, such as restrictions on BMI, age, comorbidities, etc. Pollock et al conducted a review of the literature regarding outpatient arthroplasty and found that the mean age for those undergoing outpatient total and unicompartmental knee arthroplasty was 55 to 68 years, whereas the overall age of knee arthroplasty patients nationally averaged 66.1 years. Mean BMI also varied from 27.5 to 30.8 kg/m² with many authors not reporting their values.⁴ Interestingly, the majority of studies in this review showed a predominance of males in the outpatient cohort in spite of an annual higher proportion nationwide of females receiving TKA (61.6% in 2014). Some centers have worked in collaboration with internal medicine teams to establish outpatient selection protocols or scoring systems. Meneghini et al developed the Outpatient Arthroplasty Risk Assessment (OARA) score, which records a patient’s specific comorbidities and predicts the likelihood of that patient being safe for same-day discharge after a joint arthroplasty procedure.⁵ This would allow the internist, during the patient’s preoperative medical examination, to filter the patient into either an outpatient or inpatient pathway depending on their calculated score. Courtney et al retrospectively reviewed 1012 patients who underwent hip and knee arthroplasty to evaluate which risk factors were associated with postoperative complications.⁶ They observed that 6.9% of patients developed a complication requiring physician intervention, and of those 84% occurred more than 24 hours after surgery. They concluded that chronic obstructive pulmonary disease (COPD), congestive heart failure (CHF), coronary artery disease (CAD), and liver cirrhosis were independent risk factors for developing late (>24 hours) complications.

In a separate study, Courtney et al queried the American College of Surgeons, National Surgical Quality Improvement Program (ACS-NSQIP) database, to compare complications between outpatient and inpatient TJA and identify risk factors associated with these events.⁷ Out of 169,406 patients, 1220 were identified as outpatient (0.7%). The study found that the outpatient and inpatient groups had overall complication rates of 8% and 16%, respectively. Risk factors for readmission and complications were age older than 70 years, malnutrition, cardiac history, smoking history, or diabetes mellitus. Of note, outpatient surgery alone did not account for an increased risk of readmission or reoperation.

Whatever criteria are used to select patients, utilizing a consistent group of physicians to perform medical evaluations is essential to enhance the process and ensure that the surgeon’s and internist’s goals are aligned. Frequent feedback and collaboration between the surgeon and the medical team will fine-tune the process and maximize efficiency in patient care.

As important as it is to exclude those patients who are not safe for outpatient TKA, it is also important to identify and include those patients who are otherwise good candidates but may be anxious about a same-day discharge. This requires careful patient education from the initial clinical visit. Because TKA is a highly utilized procedure, patients come to their surgeon with certain expectations, built up from the collective experiences of their peers. The surgeon must carefully and compassionately cut through these expectations and forge his or her own prescribed experience for the patient. Keys to this pathway are ensuring adequate social support, thoroughly answering all questions regarding the procedure, and providing substantial written and/or audiovisual resources for the patient. When these expectations are firmly rooted early, the patient is more likely to have a positive experience throughout their personal TKA journey.

Even more importantly, all team members throughout the clinical pathway must be united in their communications, messaging, goals, and expectations for same-day discharge. If the surgeon sets the expectation, then each team member must be trusted to maintain that expectation throughout the patient’s journey. This includes clinical receptionists, nurses, schedulers, preoperative medical consultants, perioperative nurses, anesthesiology providers, and physical therapists. This multidisciplinary approach not only ensures a consistent expectation but also empowers other staff members to participate in the patient’s instruction and thus eases the burden on the surgeon for thoroughly educating the patient. Dowsey et al prospectively randomized 163 patients into either a clinical pathway or control group prior to TJA.⁸ They reported that the clinical pathway group had a significant reduction in hospital LOS, earlier ambulatory ability,
decreased readmission rate, and more accurate matching of the patient’s discharge destination (i.e., home versus SNF). These results support that clinical pathways are not only important in preparing a patient for same-day discharge, but they can also contribute to reducing complications and improving overall outcomes.

Even if the entire team shares the same vision for outpatient TKA, patients will still have questions and anxieties leading up to surgery. Comprehensive educational resources such as pamphlets, brochures, and DVDs can be a valuable tool in reinforcing and maintaining the patient’s expectations and answering important questions. Many centers also employ “joint camps” or multidisciplinary meetings to allow patients to get acquainted with the setting and personnel they will encounter on the day of surgery. This preoperative encounter also allows physical therapists to address medical equipment needs, teach the patient how to adapt to activities of daily living, and instruct caregivers on how they can best help the patient in the immediate postoperative period. Nurses can use this platform to educate patients and caregivers on wound management and common complications. Ideally, these instructional sessions may be arranged in conjunction with the patient’s preoperative medical assessment to reduce the patient’s travel burdens. Familiarity with these concepts will help alleviate the fears and anxieties of the patient and contribute to a smooth and efficient recovery process.⁹,¹⁰,¹¹

One of the biggest roadblocks to outpatient TKA is postoperative pain. However, heavy narcotics and deep general anesthetics can leave the patient oversedated and with disruptive side effects such as nausea and vomiting, prolonging the acute recovery period and postponing the patient’s participation in physical therapy. Rapid recovery pathways overcome this challenge in three specific ways: perioperative multimodal pain management, regional analgesia, and periarticular injections. Preoperative education yet again can be a useful tool in managing a patient’s expectations prior to surgery, this time in regard to perioperative pain, and before any pharmacologic agent is administered. Working in connection with the anesthesiology team, the surgeon, and anesthetist can play a vital role in preparing the patient for the reality of postoperative pain and reassuring him or her that pain after surgery is normal, even after adequate administration of pain medications. If the patient is adequately prepared for this reality, then it will help mitigate the anxiety and fear that may arise upon awakening in the recovery room.¹²