Department of Orthopedic Surgery, Gangneung Asan Hospital, Ulsan University College of Medicine, Gangneung, Korea.
Total knee arthroplasty (TKA) is one of the most successful and effective surgical options to reduce pain and restore function for patients with severe osteoarthritis. The purpose of this article was to review and summarize the recent literatures regarding patient satisfaction after TKA and to analyze the various factors associated with patient dissatisfaction after TKA. Patient satisfaction is one of the many patient-reported outcome measures (PROMs). Patient satisfaction can be evaluated from two categories, determinants of satisfaction and components of satisfaction. The former have been described as all of the patient-related factors including age, gender, personality, patient expectations, medical and psychiatric comorbidity, patient's diagnosis leading to TKA and severity of arthropathy. The latter are all of the processes and technical aspects of TKA, ranging from the anesthetic and surgical factors, type of implants and postoperative rehabilitations. The surgeon- and patient-reported outcomes have been shown to be disparate occasionally. Among various factors that contribute to patient satisfaction, some factors can be managed by the surgeon, which should be improved through continuous research. Furthermore, extensive discussion and explanation before surgery will reduce patient dissatisfaction after TKA.
The concept of patient satisfaction was first defined by Ware et al.7) in 1873. Patient satisfaction after TKA can be associated with patients' expectations, pain relief, and functional improvement. Lau et al.2) suggested that following two perspectives, internal determinants and external components, should be considered in the evaluation of patient satisfaction. The former refers to patient-dependent factors, such as age and expectations, whereas the latter indicates patient-independent factors, such as hospital environment and surgical technique. Patient satisfaction after TKA has been described as ranging from 75% to 92%. Based on a review of the Swedish Knee Arthroplasty Registry, Dunbar et al.8) reported that 17% of the patients were not satisfied with the outcome of TKA. Schulze and Scharf9) conducted a systematic review of studies on patient satisfaction after TKA assessed between 1990–1999 and 2000–2012, which showed patient satisfaction increased from 81.2% in the former decade to 85% in the latter 13 years. Baker et al.10) reviewed the data from the National Joint Registry for England and Wales: 71% of the patients perceived improvement of knee symptoms, but only 22% rated the results as 'excellent'. Kim et al.11) reported that in spite of the clear evidence of improvement after TKA in terms of restoration of daily living activities and pain relief, patient satisfaction level was moderate.
The Knee Society Clinical Rating System (
The most common causes of patient dissatisfaction include residual pain and limited function; however, pain relief and functional recovery have demonstrated no significant correlation in many studies. Judge et al.18) reported that postoperative pain was associated with the preoperative diagnosis, such as rheumatoid arthritis, and patient's mental status, such as anxiety and depression, whereas functional recovery was affected by age and gender. Scott et al.19) noted that a high percent of patients were not satisfied with their ability to kneel, squat, and climb stairs after TKA. According to Ghomrawi et al.20), patients with expectations of high-level activities and extreme ROM reported dissatisfaction after TKA. In a study by Parvizi et al.21), 89% of the patients were satisfied with their ability to perform daily living activities and 91% were satisfied in terms of pain relief. In the study, however, only 66% reported their knees felt normal, 33% had lingering pain, 41% suffered from stiffness, 33% complained of bothering noise, swelling, or tightness, and difficulty in getting in and out of a car, getting up and down from a chair, and climbing up and down stairs were reported in 38%, 31%, and 54%, respectively.
The possible internal determinants of patient satisfaction include age, gender, patient's personality, patient's expectations, physical and psychological comorbidities, diagnosis for TKA, and the severity of arthropathy.
There is still no consensus on the influence of age on patient satisfaction. Patients were more satisfied with the outcome of TKA when they were 60 years or younger in a study by Noble et al.22). According to Scott et al.19), younger patients tended to report their expectations were met after surgery, and thus obtained greater satisfaction with the treatment outcomes. On the other hand, Williams et al.23) reported that patient satisfaction was significantly low among patients less than 55 years of age. Parvizi et al.21) described that residual symptoms and functional deficits were more prevalent in younger patients. Von Keudell et al.24) documented that satisfaction with postoperative pain, ROM, and kneeling was higher after unicompartmental knee arthroplasty in patients less than 55 years of age, whereas TKA provided greater satisfaction in patients more than 65 years of age. Therefore, it is difficult to determine whether age is predictive of the outcome of TKA. It appears that biological age, rather than chronological age, has a greater role in functional recovery after TKA.
Residual pain and stiffness are likely to be more prevalent in female TKA patients2526). However, it has not been sufficiently established as to whether gender is a predictive factor of patient satisfaction.
Gong and Dong27) retrospectively investigated the relationship between the outcomes of TKA and patient's personality classified into 4 types: patients with extroverted personality were more satisfied than those with introverted or anxious personality after TKA. In our opinion, however, the influence of personality on the outcome of TKA is not straightforward to determine due to the difficulty of categorizing various human personalities.
The degree to which patients' expectations are met can be an important predictor of patient satisfaction. Bourne et al.28) reported that unmet expectations were the strongest predictor of dissatisfaction after TKA. Scott et al.29) also showed a close correlation between patients' expectations and their satisfaction. However, patient's expectations tend to be higher than the surgeon's420). Initially after TKA, patients are mostly concerned with pain relief. In the long-term, however, they expect to recover symptomfree functions for activities that personally matter to themselves. While surgeons relate to the patients' long-term goals, they are well aware that such expectations may not be fulfilled30). Therefore, it is an important role of the surgeon to inform the patient of the possibility of unmet expectations. Contrary to these results, recent systemic reviews by Haanstra et al.31) and Culliton et al.32) have shown that there is no notable association between patient's expectations and postoperative satisfaction, suggesting the need for more objective measures of assessment.
Comorbidities have been established as a predictor of patient dissatisfaction after TKA33) in a multitude of studies. Scott et al.29) demonstrated that preoperative back pain or pain in the other joints was significantly associated with postoperative dissatisfaction. Singh and Lewallen34) reported that postoperative pain was severer in patients with medical or psychological comorbidities. Clement and Burnett35) showed generic physical health was related to patient satisfaction. Vissers et al.36) observed patients with low preoperative mental health based on the SF-12 and SF-36 scores obtained poor outcomes in terms of pain relief and functional improvement. Wylde et al.37) reported that patients with medical comorbidities were more likely to experience pain or functional disability after TKA. Fisher et al.26) noted a higher incidence of limited mobility after TKA in patients with diabetes or pulmonary disease. Although the prevalence of anxiety and depressive symptoms that are high in patients scheduled for TKA decreases significantly after surgery38), these patients tend to have lower satisfaction after surgery than those without preoperative comorbidities183738). On the other hand, some studies have shown that preoperative depression does not affect postoperative function36). Rather, patients with preoperative depression appear to obtain higher level of satisfaction after TKA than those without39).
Rheumatoid arthritis patients have been reported to have greater satisfaction than patients with other indications for surgery18). This can be attributed either to 1) the fact that the most important expectation among rheumatoid arthritis patients is pain relief, whereas patients with other diseases are more concerned with functional improvement40) or to 2) the relatively low expectation among patients with rheumatoid arthritis41).
Bourne et al.28) reported the postoperative satisfaction was low among patients who complained of severe pain while resting, lying in a bed, or sitting on a chair before surgery. On the other hand, Maratt et al.42) described that patients with severe pain or dysfunction before surgery were more likely to be satisfied after surgery as long as the preoperative symptoms did not cause severe disruption in health-related quality of life. Kim et al.43) reported patient's dissatisfaction with TKA was associated with poor preoperative WOMAC score, indicating that end-stage arthritis patients are likely to have a low level of satisfaction. However, Schnurr et al.44) have recently shown that patients with mild or moderate osteoarthritis are at an elevated risk for dissatisfaction after TKA. In a study by Polkowski et al.45), the incidence of unexplained pain after TKA was higher in patients with early-stage osteoarthritis before surgery.
Fisher et al.26) reported high body mass index, previous history of knee surgery, and disabilities as patient factors that could contribute to poor satisfaction after TKA. Other factors that can be associated with postoperative dissatisfaction include low social support and poverty1837), living alone28), and postoperative varus knee alignment3). Mann et al.46) observed improvements in outcome scores after revision TKA when it was performed by a different surgeon from the primary TKA that was considered as failure; therefore, they concluded that dissatisfaction with a previous TKA does not predispose to continued dissatisfaction after revision.
External components that can be associated with patient satisfaction include anesthesia, postoperative pain management, surgical technique, implant type, and postoperative rehabilitation.
Some studies have associated anesthesia and postoperative pain management with patient satisfaction. In general, TKA is performed under regional or general anesthesia. According to a literature review by Fischer et al.47), regional anesthesia appears to result in greater patient satisfaction after TKA. However, in a study by Harsten et al.48) where the results of TKA were compared among patients randomly allocated to receive either general anesthesia or spinal anesthesia during surgery, the general anesthesia group obtained more favorable results than the spinal anesthesia group in terms of early recovery, pain relief, dizziness or nausea, and early ambulation. A variety of attempts have been made for initial pain relief after TKA and ultimately for improved patient satisfaction. In the past, narcotic analgesics were prescribed for pain control after TKA; however, it is used less frequently these days due to the risk of complications49). According to Andersen and Kehlet50), intraoperative periarticular injections may contribute to pain relief and reduced use of narcotic analgesics. Femoral nerve blocks that are effective for postoperative pain management may also decrease the need for narcotic analgesics51). However, consensus on the efficacy of sciatic nerve blockade still remains elusive5253).
Minimally invasive TKA performed through a small incision accelerates recovery after surgery. Thus, it has been expected to improve patient satisfaction after TKA. However, Hernandez-Vaquero et al.54) reported that minimally invasive technique and the traditional surgical technique did not demonstrate significant differences in satisfaction among TKA patients. Therefore, the influence of surgical technique on patient satisfaction should be investigated in further research.
In spite of being established as an effective surgical technique, TKA has evolved continuously to better accommodate patients' desire for functional improvement. The impact of implant design on the outcome of TKA has been studied by many researchers, and some of which have demonstrated a relationship between the type of implant and postoperative satisfaction. Hamilton et al.55) conducted a prospective, double-blind randomized control trial for comparison of Kinemax TKA and Triathlon TKA, which showed that the outcome of TKA could be influenced by the prosthesis design. Baker et al.56) carried out comparisons of 6 different TKA implants: the NexGen implant (Zimmer, Warsaw, IN, USA) resulted in greater improvement after TKA than the other 5 implant types. Contrary to these studies, a multi-center randomized controlled trial by Wylde et al.57) showed no significant difference in patient satisfaction between the Kinemax fixed- and mobile-bearing TKA.
Recently, Levine et al.58) reported that rehabilitation managed by a physical therapist did not result in difference in patient satisfaction and functioning compared to neuromuscular electrical stimulation performed at home without therapist's supervision. Kim et al.59) also reported that regular passive ROM exercises did not offer additional clinical benefits to TKA patients. However, we believe that systematic rehabilitation guided by a physical therapist would be conducive to a more rapid return to normal daily activities.
TKA has been recognized as a successful treatment for knee arthritis that delivers relatively high satisfaction compared to the other surgical treatments from the orthopedic surgeon's perspective. However, it is not uncommon to observe discrepancies in patient-surgeon satisfaction: patients are often less satisfied the outcome than the surgeons expect, suggesting the need to develop more objective patient satisfaction measures. Among various factors that contribute to patient satisfaction, some factors can be managed by the surgeon, which should be improved through continuous research. One of the factors most strongly associated with postoperative satisfaction is patient's expectations: unmet expectations result in dissatisfaction. Therefore, it is important for surgeons to reach an agreement with patients on the possible benefits and risks of TKA through extensive discussion and explanation before surgery in order to reduce the likelihood of patient dissatisfaction.