There have been multiple successful efforts to improve and shorten the recovery period after elective total joint arthroplasty. The development of rapid recovery protocols through a multidisciplinary approach has occurred in recent years to improve patient satisfaction as well as outcomes. Bundled care payment programs and the practice of outpatient total joint arthroplasty have provided additional pressure and incentives for surgeons to provide high-quality care with low cost and complications. In this review, the evidence for modern practices are reviewed regarding patient selection and education, anesthetic techniques, perioperative pain management, intraoperative factors, blood management, and postoperative rehabilitation.
Key points
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Efforts to identify and correct modifiable risk factors should be undertaken before elective total knee arthroplasty (TKA).
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There is adequate evidence to support the use of multimodal pain management protocols in TKA, although debate exists over the optimal regimen.
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The advent of tranexamic acid has reduced the transfusion rate and associated complications after TKA.
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There is no consensus regarding the type, appropriate frequency, duration, or intensity of physical therapy protocols after TKA.
Introduction
Rapid or enhanced protocols to improve recovery after total knee arthroplasty (TKA) have evolved in response to efforts to improve patient satisfaction, the advent of bundled care, and the increasing practice of “fast-track” and outpatient total joint arthroplasty (TJA). The increasing demand and volume of TKAs performed have created pressure from payer sources to provide high-quality outcomes at low cost. The sharing of costs with physicians and the opportunity to share cost savings have incentivized physicians to improve preoperative, intraoperative, and postoperative care strategies. Multiple specialties, including orthopedic surgeons, anesthesiologists, and physical therapists, have contributed to improving the standard of care in “fast-track” elective TKA to make it a safe and effective procedure, even when performed in the outpatient setting. Despite these efforts, there continues to be room for improvement in patient satisfaction after TKA. Although TKA is a successful operation for most patients, there is a significant portion of patients who remain unsatisfied. In a survey of 1712 TKA patients, only 89% reported willingness to undergo another TKA, and overall satisfaction was a modest 81%. A multicenter study examining patient satisfaction in young patients found that newer knee designs have not resulted in improved patient satisfaction in younger patients.
Introduction
Rapid or enhanced protocols to improve recovery after total knee arthroplasty (TKA) have evolved in response to efforts to improve patient satisfaction, the advent of bundled care, and the increasing practice of “fast-track” and outpatient total joint arthroplasty (TJA). The increasing demand and volume of TKAs performed have created pressure from payer sources to provide high-quality outcomes at low cost. The sharing of costs with physicians and the opportunity to share cost savings have incentivized physicians to improve preoperative, intraoperative, and postoperative care strategies. Multiple specialties, including orthopedic surgeons, anesthesiologists, and physical therapists, have contributed to improving the standard of care in “fast-track” elective TKA to make it a safe and effective procedure, even when performed in the outpatient setting. Despite these efforts, there continues to be room for improvement in patient satisfaction after TKA. Although TKA is a successful operation for most patients, there is a significant portion of patients who remain unsatisfied. In a survey of 1712 TKA patients, only 89% reported willingness to undergo another TKA, and overall satisfaction was a modest 81%. A multicenter study examining patient satisfaction in young patients found that newer knee designs have not resulted in improved patient satisfaction in younger patients.
Patient optimization
Recognizing which patients are at risk for adverse outcomes after TKA is the first step in preventing them. Optimizing modifiable risk factors is imperative for success, and surgery may need to be delayed until many are corrected. Routine preoperative medical evaluation by primary care specialists is valuable in identification of many of these risk factors. Although the following risk factors are discussed individually, many patients will present with a combination of these medical comorbidities.
Psychological
Inferior outcomes have been reported with decreased mental composite scores because of conditions such as depression and anxiety. These patients may benefit from additional efforts in preoperative education and in postoperative rehabilitation. Providing additional attention to these patients through more frequent postoperative phone calls and office visits to provide psychological support can be beneficial.
Obesity
Body mass index (BMI) greater than 30 is associated with increased length of stay (LOS) and increased likelihood of discharge to a rehabilitation facility. In a large database study of morbidly obese patients, BMI greater than 40 was associated with an increase in complications, mortality, and resource use, but with a relatively modest effect size when controlled for comorbid conditions.
Anemia
Preoperative anemia should be screened for and corrected, if possible, before elective TKA. It has been associated with increased transfusion rate, infection risk, increased LOS, and an increased risk of mortality. Perioperative allogenic transfusions have also been associated with an increased infection rate in TKA in patients with increased infection risk factors such as diabetes and obesity. A multicenter study in Europe conducted in 2015 determined that strategies to identify and treat anemic patients were still underutilized.
Diabetes Mellitus
Diabetic patients are at increased risk of infection after TJA, especially those with poor glycemic control. These subjects are at increased risk of surgical and medical complications and have a higher mortality risk and increased LOS. The investigators recommend monitoring HgbA1c as a marker of long-term glucose control, which should ideally be less than 8. Early postoperative glucose management, which was first identified as an important part of preventing infection in cardiac and general surgery, is important, even in nondiabetics. Glucose should be monitored postoperatively with a goal of 110 to 140 g/dL.
Tobacco Use
Smokers are at a higher risk of multiple complications after surgical procedures, including the need for mechanical ventilation, wound healing problems, infection, and cardiac complications. Smoking cessation 4 to 6 weeks before operative intervention is recommended to decrease complications. A 2010 Cochrane Review showed that interventions including behavioral support and nicotine replacement therapy (NRT) can be effective in reducing postoperative morbidity. Obtaining a cotinine level preoperatively is one method to monitor compliance, but for patients on NRT (who would test positive for nicotine byproducts), checking an expired carbon monoxide breathing test has been described.
Malnutrition
Malnutrition places patients at higher risk of wound complications, infection, and medical complications after TKA. Markers indicating malnutrition are total lymphocyte count less than 1500 cells/mm 3 , albumin of less than 3.5 g/dL, and transferrin levels less than 200 mg/dL. As noted by Huang and colleagues, obese patients are often paradoxically malnourished, and this should be addressed before elective TKA.
Preoperative education
There are conflicting data in the literature regarding whether preoperative education is a useful intervention for TKA patients. Noble and colleagues found that patient satisfaction was highly correlated with whether preoperative expectations had been met. Culliton and colleagues found no difference in patient satisfaction in regard to preoperative expectations, but did find that postoperative expectations were correlated to satisfaction, and recommend continuing patient education through the postoperative period. However, in a 2014 Cochrane Review , no significant differences were demonstrated in regard to outcomes (either pain, function, health-related quality of life, or complications) when preoperative education was evaluated. It was recognized that preoperative education may be useful in certain populations; those with depression or anxiety, and to correct unrealistic expectations. Given the potential benefits of preoperative education, the negligible potential for harm, low cost, and in light of the decreasing hospital LOS, the investigators think that the importance of preoperative education will increase because patients spend less time being monitored and educated in the hospital.
Intraoperative considerations
Minimally Invasive Surgery
Minimally invasive surgery (MIS) TKA techniques have been proposed to offer benefits of less blood loss, reduced pain, and faster recovery. Examples of MIS TKA exposures include the mini-subvastus, mini-medial parapatellar, mini-midvastus, and quadriceps-sparing techniques. The hypothetical benefits of MIS approaches relate primarily to preservation of quadriceps function. MIS techniques require specialized instrumentation to avoid component malposition, which was a reported complication early in the development of these techniques. Although there can be an early benefit in mobility, 2- and 6-year outcomes with MIS and standard TKA approaches were no different in a recent study by Unwin and colleagues. A prospective trial of 134 patients randomized to standard versus MIS TKA (using midvastus approach) found no difference in radiographic alignment, function, or range of motion at 1 year, although MIS TKA subjects experienced slightly less blood loss and slightly more operative time.
Tourniquet Use
Intraoperative tourniquet use is recognized to be a cause of postoperative pain and was recently demonstrated to adversely affect quadriceps strength for up to 3 months postoperatively. Although increased intraoperative blood loss without tourniquet was observed by Dennis and colleagues in a randomized trial of 56 bilateral TKA, the total (intraoperative and postoperative) blood loss was not statistically different. Use of a tourniquet may simply delay intraoperative blood loss until after surgery, which may, in fact, be exacerbated by a paradoxic increase in bleeding due to reactive hyperemia.
Blood Management
Reducing intraoperative and postoperative blood loss can enable better mobilization and help to avoid complications such as fluid overload, increased infection rate, and increased LOS. Transfusion rates (and associated complications) have been significantly reduced by the adoption of tranexamic acid (TXA). The most effective dosing strategy for TXA is debated, but oral, intravenous, and intraarticular dosing regimens have been shown to be effective and safe in reducing blood loss and transfusion rate in the perioperative period. The use of fibrin sealants have been shown to reduce blood loss, but are not as cost-effective as TXA.
Drain Use
Routine use of a drain, although commonly thought to reduce the incidence of hemarthrosis and facilitate mobilization, has been shown to increase blood loss. In small randomized prospective studies, use of a drain has been shown to increase postoperative blood loss and has not been shown to affect short-term outcomes. A meta-analysis involving 1361 TKAs conducted by Zhang and colleagues found no difference in range of motion, quadriceps strength, or outcomes with or without the use of a drain.
Perioperative pain and fluid management
Anesthetic Methods
The objectives of most rapid recovery protocols in TKA are to provide pain relief and avoid complications, especially postoperative nausea, oversedation, and prolonged motor blockade. Neuraxial anesthesia appears to be safer and more effective than general anesthesia in TJA. In a study comparing use of neuraxial and general anesthesia in 500,000 TJAs, decreases in 30-day mortality, LOS, and cost were found when neuraxial anesthesia was used. Regional anesthesia has been advocated in recent years as a method to enhance postoperative pain control. Femoral and sciatic nerve blocks have both been used but are associated with prolonged motor blockade, which interferes with early mobilization and may place patients at a risk for falls. Adductor canal blocks (ACB) and periarticular injections (PAI) are recent advancements that provide equivalent pain control when compared with femoral nerve blocks, with preservation of motor function. The use of intraoperative PAI is supported by multiple randomized controlled trials. The authors’ preferred technique is to inject multiple areas of the knee with a 22-gauge needle with small (1–2 mL) quantities, with attention to the posterior capsule, periosteum surrounding the areas of bone resection, and fat pad. It remains to be determined whether ACB, PAI, or a combination of the 2 in conjunction with spinal anesthesia provide the most optimal pain control after TKA.
Analgesia
Multimodal pain management strategies have evolved to improve patient satisfaction, improve early mobilization, and reduce complications associated with opioid monotherapy. Opioids, which have been a mainstay of surgical pain management, have multiple adverse drug effects and have been shown to be associated with increased LOS and costs across surgical subspecialties. Undertreating pain with opioid monotherapy to avoid adverse effects can lead to uncontrolled pain and slower patient mobilization. Properly addressing postoperative pain with a multimodal regimen is of the utmost importance so that participation in therapy and early discharge are possible. A typical regimen involves acetaminophen, nonsteroidal anti-inflammatory agents, opioid analgesic, with or without gabapentin or gabapentinoid medication. The use of preemptive analgesia, or medication administered before tissue injury, can dampen the inflammatory cascade in response to surgery as well as lessening pain due to neuronal hyperexcitability. This multimodal regimen is most effective when continued postoperatively because of the prolonged transmission of stimuli from afferent pain receptors. Antiemetic medications with adjuvant short-acting corticosteroids are also useful in reducing perioperative nausea and vomiting. The use of corticosteroids in the perioperative period likely has a synergist effect with regards to decreasing both inflammation and pain.
Rehabilitation
There is currently no clear consensus regarding the frequency, duration, or intensity of physical therapy protocols for TKA patients. Historical rehabilitation protocols involved an early long period of immobilization followed by delayed initiation of therapy. Early in this decade, accelerated protocols were developed that focused on early mobilization using specialized care teams. These protocols were found to reduce hospital stay and cost. There is a need to establish clear targets for rehabilitation based on functional testing. The authors’ current practice is typically a regimen of 2 to 3 outpatient physical therapy visits per week for 4 to 6 weeks postoperatively. The patient is educated not to depend on the therapist and to perform their regimen 3 times per day independently. Outpatient physical therapy, in contrast to home physical therapy visits, is preferred to encourage additional patient mobility and provide better access to specialized equipment.
Preoperative Rehabilitation
Preoperative physical therapy or “prehab” has been shown to have modest effects on pain in the first 4 weeks with modest improvements in functional scores, with no difference in hospital LOS, cost, or quality of life. These effects were considered too small and fleeting to be clinically relevant in a systematic review and meta-analysis conducted by Wang and colleagues in 2016. Considering the substantial reduction in hospital LOS that has occurred during this decade, the investigators favor a single preoperative physical therapy assessment, at least with patients demonstrating significant preoperative disability. This assessment can provide valuable preoperative education, determine specific home patient needs, and is often helpful in reducing preoperative patient anxiety, which can adversely affect postoperative rehabilitation.
Limb Elevation
Elevation of the lower extremity multiple times daily in the early postoperative period is imperative to lessen lower extremity edema. Increased edema adversely affects knee range of motion and speed of patient mobilization.
Cryotherapy
Cryotherapy is a useful nonpharmacologic analgesic method that is useful in the acute perioperative and postoperative setting. There are multiple devices available that have been marketed to improve pain and swelling for postsurgical patients. There has been no significant benefit in pain, swelling, or range of motion associated with these devices, when compared with traditional cold packs. The authors advise caution with the use of advanced cryotherapy devices use due to the risk of thermal injury ( Fig. 1 ). The authors’ recommendation is traditional ice or gel packs for 20 to 30 minutes per session to minimize the risk of thermal injury.