Outpatient Surgery in Total Hip and Knee Athroplasty - A Review Article

Enhanced recovery after surgery, or rapid recovery after surgery, is a concept that was first described in the context of colorectal surgeries in the late 1990s, which adopted a multifaceted approach to the implementation of fast-track recovery protocols. These protocols accelerate recovery and reduce time in hospital in the hospital creating a smoother and more efficient process for the patient and hospital. [1] These protocols were recognized by orthopaedic surgeons as useful in total joint arthroplasty and have been widely and quickly assimilated. The main goals are to enhance recovery and reduce morbidity, and secondarily to reduce length of stay, convalescence, and costs. [2] Today, numerous institutions have implemented rapid recovery protocols for common elective orthopedic procedures such as hip and knee arthroplasty. A successful rapid recovery program encompasses many aspects. Firstly, a thorough standardized pre-operative assessment of risk factors and fitness for rapid recovery should be conducted well in advance for surgical optimization. Preoperative education should be provided, and the expectation of rapid recovery should be enforced with the patient as well as the healthcare team. Additionally, as per the American Society of Anesthesiologists, healthy patients undergoing elective procedures may continue oral hydration with clear fluids to 2 hours prior to the procedure [3]. Intraoperatively, considerations for rapid recovery should also be enforced, notably with regards to anesthetic techniques and nausea management. While admitted, postoperatively, proper fluid and pain management protocols should be maintained, as well as coordinated efforts of the nursing and physiotherapy teams [4]. Upon discharge, patients should have adequate pain control and a plan in place to manage pain satisfactory.


Introduction
Enhanced recovery after surgery, or rapid recovery after surgery, is a concept that was first described in the context of colorectal surgeries in the late 1990s, which adopted a multifaceted approach to the implementation of fast-track recovery protocols. These protocols accelerate recovery and reduce time in hospital in the hospital creating a smoother and more efficient process for the patient and hospital. [1] These protocols were recognized by orthopaedic surgeons as useful in total joint arthroplasty and have been widely and quickly assimilated. The main goals are to enhance recovery and reduce morbidity, and secondarily to reduce length of stay, convalescence, and costs. [2] Today, numerous institutions have implemented rapid recovery protocols for common elective orthopedic procedures such as hip and knee arthroplasty. A successful rapid recovery program encompasses many aspects. Firstly, a thorough standardized pre-operative assessment of risk factors and fitness for rapid recovery should be conducted well in advance for surgical optimization. Preoperative education should be provided, and the expectation of rapid recovery should be enforced with the patient as well as the healthcare team. Additionally, as per the American Society of Anesthesiologists, healthy patients undergoing elective procedures may continue oral hydration with clear fluids to 2 hours prior to the procedure [3]. Intraoperatively, considerations for rapid recovery should also be enforced, notably with regards to anesthetic techniques and nausea management. While admitted, postoperatively, proper fluid and pain management protocols should be maintained, as well as coordinated efforts of the nursing and physiotherapy teams [4]. Upon discharge, patients should have adequate pain control and a plan in place to manage pain satisfactory.
Several studies have investigated pre-operative, intraoperative and post-operative factors contributing to the safety and success of outpatient joint replacement procedures. This paper offers the results of a literature review with the goal of presenting the best available evidence from such studies. We conducted the search in Pubmed, Medline and Embase. We focused on the most recent literature with 81% of studies being performed within the past 5 years. We used the standard terms (Medical Subject Headings or MeSH in Medline and Emtree terms in Embase) as well as the words used by authors in their titles ,abstracts and keywords. Terms we used includes but was not limited to "total knee replacement, total hip replacement, ambulatory surgical procedures, rapid recovery, outpatient, office, fast track procedures). The search was performed using Boolean operators. Octogenarians receiving primary THA and TKA were discharged home >90% of the time with LOSs <2 days and low readmission rates. Revision THA and TKA patients aged 80 years and older were discharged home about 70% of the time with significantly longer LOSs than patients aged more than 80 years.

Is Rapid Recovery Hip and Knee Replacement Possible and Safe in the
Factors associated with hospital stay length, discharge destination, and 30-day readmission rate after primary hip or knee arthroplasty: Retrospective Cohort Study [7] Roger et al 2019 N = 938 THA, n = 725 TKA, retrospective cohort study Factors predicting discharge to rehabilitation unit were older age, female gender, chronic obstructive pulmonary disease, anxiety-depressive disorder, and a history of stroke. Risk factors for 30-day readmission were male gender, obesity, and discharge to rehabilitation unit.

Primary Total Hip Arthroplasty With
Same-Day Discharge: Who Failed and Why [8] Kim et al 2019 N =164, 143 discharges same day Women, patients younger than 40 years, and patients older than 60 years all had an increased risk of failing the program. Body mass index of 26 kg/m 2 or less was associated with a 40% greater risk of failure. Patients with an ASA score of 3 had a 3-fold risk of failure compared with patients with an ASA score of 2 or less. Age over 70 years (P = .007), greater than 2 self-reported allergies (P < .001), and preoperative narcotic use (P = .01) were associated with failure of SDD. Gender, body mass index, American Society of Anesthesiologists class, and prior TJA were not significantly associated (P > .05). In order to determine which patients may benefit from rapid recovery pathways after total hip and knee arthroplasty, we have reviewed the literature over the past 10 years. There is evolving consensus that certain characteristics are important predictors for successful outpatient surgery, such as: male sex, ASA class 1 or 2, lower BMI, highly motivated patients, patients with support at home and lack of cardiorespiratory comorbidities. [1,2,4,[8][9][10][11][12][13][14][15].

Predictors of (Un)successful Same-Day Discharge in Selected Patients
Several clinical tools have been developed to help predict patient outcomes in total joint arthroplasty. The Outpatient Arthroplasty Risk Assessment Score (OARA) is one such tool designed to identify patients medically appropriate for same-and next-day discharge after surgery, based on medical comorbidities. [16] It has been compared to the American Society of Anesthesiologists Physical Status Classification System (ASA-PS) and Charlson Comorbidity Index (CCI) scores with respect to length of stay prediction and has been shown to have a more precise predictive ability [17]. Other predictive tools, such as the Risk Assessment and Prediction Tool (RAPT) and Predicting Location after Arthroplasty Nomogram (PLAN) have been developed to predict need for extended care facilities and help in discharge planning after total joint arthroplasty, but these have not been tailored specifically to same day surgery [17].
One study demonstrated the confounding finding that body mass index of 26 kg/m 2 or less was associated with a 40% greater risk of failure of same day discharge. In addition, the current findings suggest that women, particularly those with lower body mass index, may have an even higher incidence of postoperative hypotension and nausea. This finding may be incidental or may be related to the inability of these physically smaller patients to reach osmotic homeostasis immediately after surgery [8]. Patients in this study with an ASA score of 3 had a 3-fold risk of failure compared with patients with an ASA score of 2 or less. [8] Another study showed greater than two self-reported allergies (P < .001), and preoperative narcotic use (P = .01) to be additional factors closely associated with failure of same day discharge after joint replacement. [5] Other studies identified risk factors which were associated with a longer length of stay. These factors included female gender, BMI > 30, non-white race, ASA score >2, Charlson Comorbidity index of > 0 and preoperative hemoglobin of less than 130 [18,19]. Some studies excluded patients which were dependent on a walker or cane and patients scheduled for complex primary replacements [10,20].
There is support for safely including patients from groups considered higher risk, such as for instance octogenarians or veterans, in same day arthroplasty protocols, although no agreement on this matter currently exists in the literature. [6,7] Interestingly, one study reported a Charnley class B2, meaning the contralateral side has previously undergone arthroplasty, to be predictive of successful same day discharge [4].
In conclusion: There are no concord amongst studies regarding the optimal patient for rapid discharge, but certain factors do predict a successful outcome: male sex, ASA score< 3, lower BMI, support at home for at least 24h after surgery, motivated patient and lack of cardiovascular comorbidities.

Perioperative Management
The rapid recovery protocols must encompass several aspects of perioperative care, and actually begin their implementation long before the patient enters the operating room. Additionally, optimal pre and intra operative multimodal pain management techniques have been shown to have potential benefit in decreasing length of stay in hospital. Multimodal, opiate-sparing analgesic regimens should be initiated the morning of surgery, and intraoperative anesthetic care should be tailored to facilitate nausea control and early ambulation with a goal of meeting dismissal criteria later that day.
With regard to intraoperative anesthesia (see Table 2), one study of over 5000 patients demonstrated shorter lengths of Stay (LOS) and higher likelihood of discharge home with Neuraxial (NA) vs General Anesthesia (GA) in the context of both primary total hip and knee arthroplasty. Mepivacaine patients ambulated earlier and were more likely to be discharged the same day than both hyperbaric bupivacaine and isobaric bupivacaine patients. Mepivacaine could be beneficial for outpatient total hip arthroplasty candidates if spinal is the preferred anesthesia type. Currently there is no consensus if NA or GA should be used for rapid discharge. Both techniques have been used successfully in rapid discharge and outpatient surgery protocols [9][10][11][12][13]18,22,24,27]. The use of peripheral nerve blocks has also shown some promise in accelerating recovery and improving post-operative pain scores, as well as it being associated with a decreased risk of adverse outcomes such as urinary retention and ileus.
[23] There is however no clear evidence to support the combined usage routinely [18,28]. Avoidance of anticholinergics and cholinesterase inhibitors during anesthesia, such as glycopyrrolate with neostigmine, should be carefully considered in outpatient TJA, particularly in stand-alone ambulatory surgery centers, given their association with urinary retention [25].

Conclusion:
The rapid protocol should encompass several aspects of the perioperative care. This includes adequate pain management (Paracetamol, Celecoxib +-Pregabalin) on the morning of surgery; even though there isn't a clear advantage of using GA or NA, the anesthetist should be cognizant of drug administration during anesthesia to avoid postoperative concerns (Nausea, vomiting, hypotension and urinary retention). Table 3  It is also reasonable to hypothesize that the surgical approach to the joint used by the surgeon, and consequently the degree of soft tissue disruption, may play into how quickly a patient will mobilize. Several studies have explored the relative benefits of certain surgical approaches, but their impact on same day discharge planning has not been extensively studied. One randomized study of 24 patients showed no differences in early discharged rates with 3 minimally invasive surgical approaches (two-incision, mini-posterior, and mini-anterolateral), that had patients enrolled in the same aggressive postoperative rehabilitation program [33]. In the total knee setting, one study of 54 patients with the use of contemporary rapid recovery protocols showed that the mini midvastus approach had no superiority over the medial parapatellar approach when quadriceps muscle strength, length of stay, pain, function, and quality of life were assessed [26].

Surgical Approaches (See
Additionally, the role of non-operative factors such as the recovery setting has been shown to impact the rapidity of a patient's recovery. Husted et al. demonstrated that patients who stayed in the day surgery unit postoperatively were more likely to be discharged home after fulfilling criteria than patients admitted to the arthroplasty ward. [9] Twenty four out of twenty-five patients who stayed in the Ambulatory Surgery Centre (ASC) compared with 20/25 of the patients on the arthroplasty ward were discharged on the day of surgery following fulfillment of discharge criteria (p = 0.08). All THA patients were discharged on the day of surgery and significantly more TKA patients were discharged from the ASC (15/16) vs. from the ward (9/14) (p = 0.04). Therefore, the logistical setting may facilitate achieving discharge criteria earlier, especially in TKA. Currently there are no definitive conclusions that can be made regarding the best approach for rapid discharge or outpatient surgery. Multiple studies used the direct anterior approach [10,14,18,22] while others had great success with the posterolateral approach [9,11,13]. This was also similar for knee replacements, where a subvastus approach was used [34] compared to the standard medial parapatellar approach [9,11,13,28]. Most studies did not used drains postoperatively [9,12,18,13,28].
Conclusion: There is no clear direction regarding surgical approach in total knee and total hip replacements. There is greater success in outpatient surgery with patients in an ACS due to factors that include better patient selection and environmental expectations. This pathway however can still be successful in a general hospital setting. Table 4 Postoperative management, which includes medical management, pain management and physical therapy, after surgery is crucial to the success of the outpatient program. This starts in the recovery room and extends after the patient has left the hospital and is managing at home. Most studies start with physiotherapy on the day of surgery, with emphasis on early mobilization [18,22,28]. Physiotherapy can even be started in the recovery room if resources are available. Hospitalists and anesthetists can be involved to manage patients aggressively to control nausea,vomiting ,manage pain, maintain fluid balance and addressing medical concerns if they arise [9,18]. Three key issues that need to be addressed aggressively are dizziness, nausea and vomiting. Both these issues could lead to poor mobilization and prolonged stay in hospital. Therefore, having a dedicated anesthetist or hospitalist assigned to the outpatient ward might be very useful in addressing these concerns in an urgent manner [9,18]. The most common medication administered to patients for nausea and vomiting is Ondansetron, and fluid boluses should be liberally administered to control hypotension and subsequent dizziness. Some studies demonstrated the benefit of having outpatient surgery patients in the same room, even outpatients from different specialties. By placing outpatient surgery patients in-between inpatients, they might become discouraged leaving the hospital on the same day. Logistically that might be difficult for a hospital to have a separate ward available, only for day surgery patients. They also mentioned that outpatients should be placed in recovery beds. Not only can the bed be placed in reverse trendelenburg position (which will help to overcome orthostatic hypotension), but it is less comfortable than ward beds which will in turn encourage patients to get up and about earlier [9,13]. The percentage of patients being discharged as planned on the operative day varied greatly between studies from 24.1% -100%. The most common reasons cited for staying longer than anticipated is nausea and vomiting, dizziness, hypotension, pain and patient preference. Other reasons also mentioned included female sex, age >75, BMI >35 and lack of safe mobilization [10,12,13,15,20].
Conclusion: Postoperative management is crucial for the success of an outpatient program. This includes a multidisciplinary approach (physiotherapy, nursing, anesthesia and hospitalists) to address all the issues associated with outpatient surgery. Availability of these essential resources might be a barrier in instituting an outpatient surgery program. Pain management postoperatively is a balance between adequately controlling the pain without causing too many side effects that might delay discharge.  Table 5 The length of stay after a total hip and knee replacement have decreased over the past several decades. This was achieved due to advancements in surgical techniques, pain control, and management of bleeding [35]. This was mainly driven by the goal of decreasing healthcare costs as well as the benefits seen with early mobilization, no compromise in outcome and no associated increase in complications in select patient populations [10,35]. Multiple authors attributed the success of outpatient surgery to strict criteria that were developed and applied to potential candidates for same day surgery. Certain criteria were used more commonly among studies. These include age, BMI, Charlson Comorbidity Index (CCI), support and physical home location in relation to the surgical hospital. Patients were deemed safe to undergo outpatient surgery if their age was less than 75 years of age [10,20,27,35,42]. Some authors used 80 years of age as their cutoff [41,18]. A body Mass Index (BMI) of less than 40 kg/m 2 was used as a strict criteria [10,11,15,18,27]. One study used a BMI cutoff less than 45 kg/m 2 [41]. Most studies agreed that a low CCI should be used as an uncompromising criterion [9,[12][13][14]20,27,35,[39][40][41][42]. Patients were more readily considered for outpatient surgery if they had family support at home [9,10,11,14,17,20,22,40,28,39], and if they reside close (within 60 minutes) to their surgical hospital [11,28,40,41,42]. Other factors (albeit not routinely used) also considered in certain studies important for outpatient surgery include: non-complex orthopaedic cases [10,20], opioid naive patients [10], independent functional state [41] and no walker/wheelchair for mobilization [10]. Comparing the complications (minor and major) between outpatient surgery and inpatient surgery is very controversial. The majority of studies however show comparable complication rates between outpatient and inpatient surgery [9,10,11,12,18,22,2 8,31,35,40,41,42]. These comparable complication rates between inpatients and outpatients were even seen in studies where no, or minimal criteria was used for outpatient surgery [10,20,22]. The majority of the studies however adhered to strict criteria for outpatient surgery.

Patient Satisfaction And Postoperative Complications (See
Some conclusions regarding readmissions can be made comparing the results of all the studies evaluated. Most studies did not demonstrate a difference between readmission rates at 30 days or 90 days post-surgery in both the inpatient and outpatient groups [11,20,22,27,28,31]. This was similar for emergency department visits [10,11,20,22,28]. Total knee replacements done as outpatients might have a higher readmission rate compared to total hip arthroplasties [35,42]. Generally, the readmission rates for outpatients varied between 0.34% -5.1% [15,27,37,39,41]. The most common causes for readmission included, but was not limited to gastro intestinal bleeding [18,37], deep venous thrombosis [18,36,37,38], wound complications [18,36,37,38] and stiffness in the operated joint [37,38]. Some studies identified outpatients surgery as the culprit for higher revision rates [36,38,39], due to implant loosening and/or implant malpositioning, although that has not been confirmed by the majority of the studies. In contrast, one study demonstrated a statistical difference in favour of outpatient surgery in regards to minor complications [27]. Limited studies compared pain scores and satisfaction between the outpatient and inpatient surgery group. Four out of the six studies that reported on pain, demonstrated statistically significant improvement in pain in the outpatient surgery group [12,1427,36], while one study showed no difference [40] and one study demonstrated better pain control in the inpatient group, albeit only on post-operative day 1 [10]. Satisfaction was rated as 80% very satisfied and 20% satisfied in the outpatient surgery group [14,39]. When comparing satisfaction between the inpatient and outpatient surgery group, there was no clinically significant difference [40,42-53].

Conclusion:
If surgeons embark on outpatient surgery it is imperative to use strict inclusion criteria for the best possible outcomes. The most common criteria used included ASA <3, support at home, BMI <40 and no cardiovascular disease. Outpatient surgeries do show comparable complication rates, satisfaction and pain scores compared to standard inpatient surgery.

Ten Step Protocol
• Patient selection is crucial : consider using patients younger than 75 (other studies use 80 as their cutoff)), BMI < 40kg/m2 (some studies use 45 kg/m2 as their cutoff), opoid naïve patients, not using a walker /wheelchair; elective unilateral non-complex total joint replacement, no significant medical comorbidities that might require inpatient monitoring; assistance at home, no history of prior pulmonary embolus or a history of a myocardial infarction in the past year. Patients were deemed also to be candidates if they reside within 60 minutes of the operating hospital.

•
Pre-operative care: Preoperative education and counselling is of utmost importance. Patients should meet with the surgeon and-or physical therapist and-or nurse prior to surgery to discuss all the aspects of the perioperative period and to prepare them for same day discharge. Patients can then practice walking with a walker, crutches or cane. This meeting can also be used to discuss proper pain management postoperatively and hip precautions following a total hip arthroplasty. Patients requiring social services postoperatively should be identified and preparations can be made to meet social services preoperatively should the need arises.

•
Preoperative pain management on the morning of surgery should be opoid sparing and can include multiple medication combinations with the most common listed as Celecoxib 400mg, acetaminophen 1g and Pregabalin 75mg orally.

•
Anesthesia should be involved early on in the plan to embark on outpatient surgery. Anesthetists can help with outpatient surgery patients by minimizing medications that could lead to urinary retention,nausea and-or dizziness. Preferably no epidural or intravenous narcotics should be administered during surgery. Currently the jury is not out regarding spinal or general anesthesia and either is acceptable for outpatient surgery. Patients should be adequately hydrated during the surgery to avoid postoperative dizziness. Sedation during the surgery should be in the form of Propofol (short acting agent). Additional intraoperative medications for instance Odansetron and/or Dexamethasone should be considered to avoid nausea and vomiting postoperatively.

•
Recovery room protocol should include aggressive treatment focussing on hydration, nausea and vomitting and pain management. This include judicious intravenous fluids (i.e. Ringers lactate), medications directed at nausea (i.e. Odansetron) and pain management (anti-inflammatories, Acetominophen) to prevent hypotension, nausea and vomiting and pain respectively.

•
Surgical care: The surgeon should use techniques that minimizes soft tissue damage. Currently there is no clear evidence to support the superiority of one approach over the other in both hip and knee replacements, and surgeons can safely use the approach they are the most familiar with. Some surgeons choose to use a minimally invasive approach (subvastus approach in total knee arthroplasty), in non complex joint replacements or if their BMI is less than 40kg/m 2 . Timing of surgery (first 1-2 cases of the day) is crucial to optimize pain control and allow enough time for patients to fulfill the day surgery discharge criteria (see Table 7). Even with doing outpatient surgery cases as the first two cases of the day, surgeons should anticipate that each part of the protocol do take time and essential resources (nursing, anesthesia, hospitalist and physiotherapy) should be scheduled to stay until the patients are discharged. Some surgeons preferred periarticular infiltration, limited or no-tourniquet usage without any clear evidence supporting its widespread usage.

•
Postoperative Ward care: Patients should be monitored closely, either by a dedicated anesthetist or hospitalist, to address common concerns aggressively. This includes treating nausea and vomiting with medications (i.e. Odansetron) at frequent intervals and treating hypotension with fluid boluses. Pain management is also of utmost importance, and should be aggressively treated (see Table 7). If a dedicated anesthetist or hospitalist is unavailable then nursing staff assigned to the outpatient surgery patients with clear orders can fulfill the same role. Physical therapy should be started as soon as possible in the ward. Physiotherapy can even be started in the recovery room. Patients should be assessed while on the ward to see if they will fulfill the discharge criteria (see Table 6). Patients should be placed in rooms with other patients also partaking in outpatient surgery to help with motivation to be discharged.

•
Discharge: Always plan for a small percentage of outpatients to stay longer in hospital. There should be a system in place to deal with patients that is unable to be discharged home. That involves admitting patients to the inpatient ward or having patients transported to a hospital for admission if the patient was operated on at a facility without admission privileges. In the United States of America, virtually all the third-party payers impose a major financial penalty upon the surgical facility if a transfer to an alternative site becomes necessary. Therefore, the site of the surgery should ideally possess the capability of an overnight stay if deemed necessary. A recurring problem for patients who are discharged home is a lack of knowledge about the home environment and the degree of support by suitable family members or friends. Ideally an assessment of the home prior to the surgical procedure should be undertaken but the financial and manpower resources to facilitate that are rarely available.

•
Consider instituting clinical pathways, structured programs or preventative interventions to decrease length of stay and minimize complications. This will give the new rapid discharge program the best chance to optimize outcomes.

•
Everything should be perfectly executed to do outpatient total joint arthroplasty -any error or delay from any part of the team will result in failure. Consider starting with a "fast track" program first focussing on total hip arthroplasty or unicompartmental knee replacements. Once a "fast track" program is instituted and running smoothly should one decide to embark on outpatient surgery.  • Pregabalin 50-75 mg BID P.O.
• Cryotherapy or icing Table 7: Pain management options postoperatively.