Introduction

When the first edition of this book was released, primary total knee arthroplasty (TKA) was a procedure that had a mean length of stay of around 7 days. Dr. Krackow was a pioneer and advanced the issues pertaining to length of stay throughout his career. Advances in operative techniques, anesthesia, and perioperative analgesia have allowed same-day TKA to become a reality. Outpatient total joint arthroplasty has become more popular, with goals to decrease costs while still providing high-value care. To ensure an efficient, effective, and safe outpatient TKA program, it is imperative to establish appropriate protocols. A multidisciplinary team, including the surgeon, anesthesiologist, nurses, operating room (OR) staff, and therapists, is required to set up a successful and safe outpatient total joint program.

Historically, TKA has been performed in the inpatient setting with a 5- to 10-day hospital stay. Patients remained in the hospital to be monitored for postoperative acute blood loss anemia, pain control, and mobilization with physical therapy. Improvements in pharmacological and surgical techniques have markedly reduced the operative blood loss, and fewer patients are requiring postoperative transfusions for anemia. Multimodal pain control has minimized postoperative pain, allowing earlier mobilization and early discharge. The many innovations in total joint arthroplasty and perioperative care have contributed to the successful transition of TKA to the ambulatory setting.

An estimated 680,000 TKAs were performed in the United States in 2014 and this number is expected to increase to 1.26 million by 2030 according to 2000 to 2014 trends. Policies have been instituted that have incentivized patients and physicians to reduce the cost of TKA. The most effective ways to reduce costs are by reducing the lengths of stay, complications, and readmissions. Outpatient total joint arthroplasty procedures, as a whole, have the potential to save up to $7000 per procedure compared with the inpatient setting. Medicare pays for approximately 55% of TKAs in the United States. In 2018 TKA was removed from the Medicare inpatient-only list. Since that time, there has been a marked increase in the number of TKAs done on an outpatient basis. According to Medicare Fee-for-Service Part A claims data, TKA claims went from 0.2% outpatient coding in 2017 to 36.4% in 2019.

It should be noted that there are major differences between performing a TKA in the hospital setting with the intent to discharge the patient on the same day and performing one at a stand-alone ambulatory surgery center (ASC). Even though TKA in a stand-alone ASC may be considered safe for most patients, this type of program requires a team approach from anesthesia, OR support staff, physical therapists, and nurses, with appropriate measures to account for the possible need for a 23-hour overnight stay, which may not be possible at all centers.

Multiple studies have concluded that there are no increased risks of adverse events or complications with a shorter length of stay with outpatient TKA. In a metaanalysis comparing complication rates between inpatient and outpatient total joint arthroplasties there was no increased risk of major complications, readmissions, deep venous thromboses (DVTs), urinary tract infections, pneumoniae, or wound complications with outpatient TKA. These studies suggest that arthroplasty surgeries can be performed safely in an ASC in appropriately selected patients without increased risks of complications. Kelly et al. found that patients who had surgery performed in the ASC had higher patient satisfaction scores in pain management, staff interaction, and preparedness for discharge. Thus reducing discharge delays and improving patient satisfaction scores are paramount considering the financial incentives provided by the Centers for Medicare and Medicaid Services.

Patient Selection

Outpatient TKA may not be feasible or safe for all patients. In the same manner as for traditional TKA patients should be evaluated by their primary care physician preoperatively to note any ongoing medical problems. The first three chapters in this book focus on understanding the comorbidities of patients and how to optimize them. This is important when deciding whether a patient is a good candidate for a same-day discharge or a procedure to be done in an ASC. Patients should be medically optimized for a total joint arthroplasty by correcting modifiable risk factors. An evaluation should be performed by both the surgeon and the anesthesiologist before surgery to determine whether the patient would be a good candidate for TKA at an ASC.

Patients who have specific comorbidities, such as coronary artery disease, diabetes, body mass index (BMI) >40, peripheral vascular disease, chronic obstructive pulmonary disease (COPD), congestive heart failure, cirrhosis, chronic kidney disease, preoperative opioid use, advanced age, higher American Society of Anesthesiologists (ASA) score, and higher Charlson Comorbidity Index, have a higher risk of failure to be discharged or a higher risk of readmission. Patients with these comorbidities may not be good candidates for TKA in an ASC.

Some common criteria used for determining eligibility of patients for outpatient total joint replacement are age <70 years, ASA score I or II, primary total joint arthroplasty, hemoglobin >10 preoperatively, assistance at home, preoperative independent ambulation, and BMI <40. Some exclusion criteria commonly used are coronary artery disease, COPD, congestive heart failure, cirrhosis, chronic kidney disease, HIV positive, preoperative opioid consumption, and chronic pain syndromes (fibromyalgia). These criteria can be used as a guide, but ultimately it should be a joint decision by the patient, surgeon, and anesthesiologist.

When it is determined that TKA in the ASC is appropriate for a patient, it is important to adequately prepare the patient for what will be involved in the preoperative, perioperative, and postoperative settings. It is imperative that appropriate patient education be relayed not just to the patient but also to family members. A video or class that educates the patient on the importance of the preoperative steps and the postoperative risks and physical therapy guidelines can be productive. The literature presents conflicting data on preoperative education with regard to patient satisfaction, but the potential benefits and minimal harm of patient education will likely improve patient expectations. DeCook suggested multiple elements to consider with regard to patient preparation ( Table 6.1 ).

Anesthesia and Preoperative Blocks

Advances in anesthetic techniques and postoperative pain control have allowed earlier mobilization and reduced opioid consumption. Controlling pain in the early postoperative period has a profound effect on postoperative recovery in patients with TKA. Reduced pain allows more aggressive therapy and range of motion exercises in the early postoperative period, which can improve recovery and facilitate an early discharge home. Combining a neuraxial anesthetic approach, an adductor canal block, and periarticular injection can be an effective approach to minimize postoperative pain.

Ambulatory Surgery Center Versus Hospital Setting

From a facility standpoint, there are numerous differences in performing outpatient TKA in the ASC versus the hospital setting. The most obvious difference is the overall limitation in space. DeCook et al. noted that the physical space of the ASC must be assessed from an instrumentation and implant standpoint. Whereas hospitals have ample space for various trays, revision instrumentation, and various sizes of implants, the ASC in general may not have the same capabilities to house the same amount of equipment found in the hospital setting. Therefore it is imperative during the surgical planning for outpatient TKA to have proper communication among the surgeon, vendors, and OR personnel to ensure that the proper instruments and implants are available on the day of surgery.

Operating Room Staff and The Team Approach

A successful TKA requires a team approach whether it is conducted in an inpatient or an outpatient setting. The surgeons, primary care physicians, anesthesiologists, nurses, OR staff, and therapists are all vital in a successful total joint arthroplasty program. For a same-day TKA program to be successful, the multidisciplinary team approach is imperative.

Surgical scrub technicians play a vital role in the efficient flow of the operation during TKA. Surgical technicians who are experienced in ASC procedures may not be well acquainted with the instruments or the typical flow of total joint arthroplasty surgery. Before starting an outpatient arthroplasty program, it is advisable to educate any surgical staff on protocol and specialized equipment in the hospital setting or conduct a walkthrough with a mock ASC setup. An experienced, well-trained surgical technician is an important factor in creating an efficient operation and should not be overlooked.

The anesthesia team, composed of an anesthesiologist and often a certified registered nurse anesthetist (CRNA), plays an important role in the success of outpatient TKA. The team has an integral effect on controlling the patient’s pain and nausea, which can be a limiting factor for discharge. The anesthesia team should be well versed in general anesthesia, spinal anesthesia, and regional blocks. Optimally, anesthesia allows quicker recovery on the day of surgery, allowing the patient to mobilize and be safely discharged home while minimizing pain, nausea, and other undesired side effects of anesthesia. Good communication between the surgeon and the anesthesia team allows adequate planning and optimal outcomes.

Physical therapy in the immediate postoperative period is a cornerstone for safe discharge in same-day surgery. Therapists should be trained for total joint arthroplasty therapy and should understand the goal of patients meeting their therapy milestones and safely being discharged home the same day. The implementation of motor-sparing regional blocks, periarticular injections, and improved surgical techniques have allowed early mobilization. Physical therapy protocols for outpatient total joint arthroplasty focus on safe transfers into and out of bed, ambulation for a specified distance, and sometimes stair walking. Inquiries should be made into the conditions present at the patient’s site of convalescence so that appropriate patient education can be provided on navigating special circumstances.

Developing Standards and Care Paths

Development of accelerated care pathways and standardized protocols has been shown to expedite discharge across many procedures, including TKA. Care pathways facilitate coordination among the patient, surgeon, anesthesiologist, nursing staff, and physical therapist. A successful care pathway for TKA is an essential tool for accelerated recovery and same-day discharge. Protocols are developed with the goals of accelerated recovery for the patient through surgical techniques and optimal control of nausea, hypotension, pain, and anxiety.

Enhanced Recovery After Surgery (ERAS) protocols have been implemented for numerous surgeries across many specialties, with pathways developed specifically for TKA. These protocols encourage patients to drink clear fluids up to 2 hours before surgery. Several studies have shown decreased lengths of stay, lower complication rates, and lower total costs but no changes in 30-day readmission rates with the implementation of accelerated recovery pathways.

The ERAS Society released consensus recommendations for total joint arthroplasty protocols. They gave these “strong” recommendations:

• 1.
  

  Patients should routinely receive preoperative education and counseling.

  
  
• 2.
  

  Controllable risk factors (e.g., smoking cessation, alcohol abuse cessation, correction of anemia) should be optimized before surgery.

  
  
• 3.
  

  Clear fluids should be allowed up to 2 hours before surgery and solids up to 6 hours before surgery.

  
  
• 4.
  

  Both general anesthesia and neuraxial techniques can be used.

  
  
• 5.
  

  Local infiltration is recommended for TKA as part of multimodal pain management.

  
  
• 6.
  

  Patients are given multimodal nausea and vomiting prophylaxis postoperatively.

  
  
• 7.
  

  Tranexamic acid is recommended to reduce perioperative blood loss.

  
  
• 8.
  

  Multimodal regimens should include acetaminophen and nonsteroidal antiinflammatory drugs for patients without contraindications.

  
  
• 9.
  

  Body temperature should be maintained both preoperatively and postoperatively.

  
  
• 10.
  

  Patients should receive systemic antimicrobial prophylaxis intraoperatively.

  
  
• 11.
  

  Patients should receive venous thromboembolism prophylaxis in line with local policy.

  
  
• 12.
  

  No recommendations for surgical approach.

  
  
• 13.
  

  Fluid balance should be maintained to avoid both overhydration or underhydration.

  
  
• 14.
  

  Patients should have an early return to normal diet postoperatively.

  
  
• 15.
  

  Patients should undergo mobilization as early as they are able.

  
  
• 16.
  

  Objective discharge criteria should be used.

  
  
• 17.
  

  There should be routine review and improvement of care pathways.

Standardized accelerated recovery protocols should be implemented at all institutions to give clear guidance to the perioperative care of TKA patients in the outpatient setting. Care pathways advise all parties to aid in the rapid recovery of patients and allow safe discharge home the same day of surgery. Implemented protocols should be routinely examined and improved.

Perioperative Care

Intravenous (IV) antibiotic prophylaxis of cefazolin should be administered within 1 hour of incision for TKA. Two grams of cefazolin should be given for patients who weigh 80 to 120 kg and 3 g should be administered for patients over 120 kg. For patients who are allergic to penicillin, 900 mg of clindamycin IV or 15 mg/kg of vancomycin IV antibiotics can be given. Modest decreases in surgical site infections have been shown with a combination of cefazolin and vancomycin in patients at high risk of methicillin-resistant Staphylococcus aureus (MRSA) infection or with a positive MRSA nasal swab. In the inpatient setting patients may receive 24 hours of antibiotic prophylaxis after TKA. Tan et al. evaluated 20,682 total joint arthroplasties and found a periprosthetic joint infection rate of 0.6% (27 of 4523) in patients receiving a single dose of prophylactic antibiotics compared with 0.88% (142 of 16,159) in patients who received the complete 24-hour regimen. This study suggests that additional antibiotics after skin closure may not be needed in primary total joint arthroplasty.

Tranexamic acid (TXA) has been shown to decrease postoperative blood loss and transfusions in TKA. The American Academy of Orthopaedic Surgeons recommends administration of TXA for all patients undergoing TKA who do not have contraindications, such as history of thromboembolic or ischemic events. TXA has been administered orally, topically, and intravenously, all showing effective decreases in blood loss compared with placebo. Fillingham et al., in a network metaanalysis on TXA use in TKA, reported a mean difference in blood loss between 225 and 331 mL with the use of TXA compared with placebo. No differences in blood loss were found between the various administration routes or the number of doses given. They found a statistically significant decrease in blood loss and postoperative transfusions when a single IV dose was administered before incision compared with a single IV dose given after incision. In the ASC TXA should be used in all TKA patients who do not have contraindications.

Discharge Criteria

Standardized discharge criteria should be established when transitioning to TKA in the ASC setting. These criteria may differ between institutions, but the same principles apply. Patients should be able to tolerate oral intake without significant nausea. Pain should be well controlled on oral pain medications. Patients should work with physical therapy for gait training, transfers, and stairs if these are present in the patient’s home. Physical therapy specific mobilization goals may include ambulating 100 feet, transferring with minimal assistance in and out of bed, and using the restroom. Some patients may be required to stair-walk the equivalent number of stairs that are required to enter the patient’s home. A single episode of controlled voiding should be demonstrated before the patient leaves the facility. A list of common discharge criteria are outlined in Table 6.2 .