Issues related to the patients’ preoperative and postoperative physical and mental states

The general states of preoperative physical and mental health are highly correlated with patient satisfaction and outcome after surgery. Patients with preoperative health issues such as mild to moderate arthritis have a higher risk of dissatisfaction after TKA surgery. This finding does not represent an indictment but surgeons should inform those patients about the increased dissatisfaction risk. Patients who have disproportional pain to the radiographic findings may not have the same outcomes and satisfaction, mainly because of higher sensitivity to pain. Patients with other musculoskeletal issues, such as low back pain or pain in other joints, also have a higher risk of being disappointed. These patients showed less improvement after undergoing TKA with regard to perceived physical well-being. Other factors for high risk of dissatisfaction include increasing age and heart disease as well as sensitivity to pain, fibromyalgia, and patient-related factors that lead to complications and dissatisfaction, such as smoking, drug abuse, obesity, and diabetes. Patients with low back pain were more likely to be dissatisfied with their TKA, irrespective of their preoperative mental well-being. In one study, patients with no back pain had a postoperative score of 41.8 on the Medical Outcomes Study Short Form 12 (SF-12) Physical Health Composite Scale (PCS) and a score of 52.4 on the SF-12 Mental Health Composite Scale (MCS). In contrast, patients with back pain had scores of 35.5 and 48.5 on the SF-12 PCS and MCS respectively. Patients with self-reported allergies reported lower levels of satisfaction after undergoing TKA, as shown by McLawhorn and colleagues. The investigators state that patient-reported allergies are a criterion for somatoform disorders, which may explain the lower levels of satisfaction associated with those allergies.

If a patient’s general health degraded after their TKA, the patient was less likely to be satisfied with the knee procedure. In one study, out of 2350 patients who underwent primary unilateral TKA, 7.2% of patients reported no change and 2.3% of patients reported a worsening of their quality of life at 2 years postoperatively. Higher baseline levels of quality-of-life scores for pain, stiffness, and function were associated with less reported improvement after surgery, which means that a TKA performed in patients with isolated and less destabilizing knee osteoarthritis carries the risk of dissatisfaction. This finding shows how unrelated health issues can have a negative impact on patient satisfaction after a specific operation. In contrast, patients who have knee-related issues for a longer period of time, such as chronic disease, are more likely to be satisfied after undergoing knee surgery. For example, in one study in Sweden, only 14% of 3203 patients with rheumatoid arthritis were dissatisfied, whereas 30% of 191 patients with osteonecrosis were dissatisfied.

Expectations

Patient satisfaction after TKA seems to be strongly correlated with the fulfillment of the preoperative expectations. In one study, a group 4709 patients received hip and knee replacements; before the surgery they completed patient-reported outcome measurement questionnaires, Oxford Hip or Knee Scores, and SF-12s health assessments as well as follow-up questionnaires after 6 and 12 months. Final patient satisfaction and meeting expectations had an r value of .74, with a statistical significance of less than 0.001 (which means there is a high correlation). The r value, also referred to as the Pearson r , is a measure of linear correlation. The value ranges from −1 (negative linear correlation) to +1 (positive linear correlation). In contrast, a literature review that analyzed the results of 5 studies on patient satisfaction after TKA found that there was no significant relationship between expectations and satisfaction in the 2 studies that included this facet of satisfaction. Patients who had unrealistic expectations, like those who thought they could engage in strenuous activity 12 months after their surgery, were less satisfied. In this particular study, strenuous activity was calculated by multiplying the average hours of activity per week by the activity’s metabolic equivalent, and baseline activity was measured using the Historical Leisure Activity questionnaire.

Another key issue related to expectations is pain anticipated after surgery. In one study, patients who had levels of pain that were within their levels of expectation were satisfied overall. The patients were asked what their expectations were with regard to pain, and these were graded on a 4-point Likert scale. After 6 months, the patients were asked whether their expectations had been fulfilled with regard to pain, limitations of activities, and overall success of the surgery. In another study, 1 group of patients was debriefed verbally and given an information leaflet describing what they could expect from the surgery with regard to pain, pain management, physiotherapy, and the importance of taking an active role in communicating their symptoms with staff. The patients in the treatment group all stated that they were satisfied or very satisfied with their pain management, whereas the patients in the control group were more dissatisfied. Such a result emphasizes the importance of preoperative joint conferences and educational classes.

Patient age

In some studies, increased age was positively correlated with higher patient satisfaction whereas in other studies, the opposite was true. For example, in 1 study, older patients were less satisfied with their surgeries overall, possibly caused by/because of higher complication rates. In contrast, another study found that older patients were more satisfied with their TKAs. Patients 55 years old and younger, patients between the ages of 55 and 64 years, and patients more than the age of 65 years had mean satisfaction scores of 7.1, 7.7, and 8.3 respectively. Notably, satisfaction clearly increased with age, most likely because younger patients had higher expectations with regard to their recovery time and subsequent activity level. Similarly, in one study featuring 45 men and 35 women aged 41 to 89 years, younger men had higher (and perhaps unrealistic) expectations regarding the outcome of their surgery and were less satisfied than women. In this study, 71 implants were cemented posterior cruciate-retaining prostheses, 6 were cemented posterior-stabilized prosthesis, and the remaining 3 were a Press-Fit condylar system. In other studies, age had no effect on patient satisfaction. For instance, one study outlined how, in a study of 989 TKAs in 755 patients (248 male, 507 female), satisfied patients were 65.1 ± 8.9 years old, and dissatisfied patients were 64.3 ± 10 years old. Thus, there is no uniformly conclusive evidence showing that age is a factor in one way or another.

Surgical approach

Although different so-called minimally invasive surgical approaches are currently used for TKA, there is limited high-quality scientific evidence supporting improved outcome or patient satisfaction with their use. In a recent review, Costa and colleagues examined all level I and II data on surgical approach and outcome for TKA. The minimidvastus surgical approach seemed to have improved quadriceps muscle function at 1 and 3 months, and fewer complications compared with other minimally invasive and standard approaches. The minimally invasive lateral approach had the highest complication rate. In another systemic review and meta-analysis, the subvastus but not minimidvastus approach had a shorter hospital stay and decreased blood loss compared with the medial parapatellar approach. The medial parapatellar approach was also associated with a longer period to straight-leg raising. Range of motion was similar with all 3 approaches at 1 year. A prospective randomized study comparing the subvastus and midvastus approaches showed no differences in operative time, total blood loss, straight-leg-raising test, range of motion, or patient preference at 3 months and 2 years. In a prospective study of bilateral TKA comparing the medial parapatellar approach in one knee and the minimidvastus approach in the other, in a comprehensive analysis involving pain score determination, patient preference, gait analysis, and strength testing, the only significant difference was increased isokinetic and isometric extension torque at 3 weeks in the minimidvastus group. In addition, a meta-analysis of 18 randomized clinical trials comparing the minimidvastus surgical approach with the standard medial parapatellar approach showed improvements in pain and range of motion at 1 to 2 weeks with the former, but no other differences in the myriad of other outcome variables measured between 6 weeks and 1 year. However, the minimidvastus approach took longer to perform. Therefore, the surgical approach plays a minor role for long-term satisfaction after TKA.

Alignment

Most surgeons soon realize that patients are displeased with residual deformity after total knee replacement has been performed. Despite this logical observation, few studies have reported data to substantiate it. In a retrospective review of 500 TKAs in Japanese patients with a minimum follow-up of 2 years, Matsuda and colleagues found that residual postoperative varus alignment and advanced age negatively affected patient satisfaction. In another study, 23% of Canadian patients were dissatisfied with their limb alignments after TKA, and had a poorer perception of their pain and range of motion, even though their Knee Society and Oxford Knee Scores were similar to those who were satisfied with their alignment. The current clinical scores therefore have a ceiling effect and cannot accurately capture patient-relevant outcomes.

How much knee flexion is needed in daily life?

The amount of flexion needed to accomplish most activities of daily living is controversial. One study noted that patients only flexed their knees more than 90° 0.5% of the time. However, 135° of flexion seems to be needed for all daily activities in Western cultures. Perhaps even less flexion, 128° to 132°, is sufficient. In another study, range of motion was only ranked as the ninth most important factor related to patient satisfaction after TKA; other activities (such as climbing stairs) were considered to be of greater importance. In India, where squatting and other high-flexion activities are more common, one study concluded (surprisingly) that “deep knee flexion is not an essential prerequisite for patient satisfaction after total knee replacement.” Furthermore, daily activity (with regard to exercise) had no impact on patient satisfaction.

High-flexion implants

Most conventional TKAs result in flexion of approximately 100° to 115°, which is sufficient to accomplish virtually all activities of daily living (83° of flexion is needed to climb stairs, 90° to descend stairs, and 93° to rise from a chair). However, now that TKAs are being performed in younger, more active individuals, there is a desire to obtain even more flexion by some. This extra flexion may be even more important in societies in which squatting and specific methods of kneeling and sitting are everyday occurrences. High flexion (the ability to bend the knee >130°) is a recent trend both in terms of new knee replacements and general postoperative function. Several studies have shown that a single-design, high-flexion, mobile-bearing, posterior-stabilized knee resulted in less pain and higher overall satisfaction. In one study, the flexion obtained varied from 85° to 155°. However, in another study, patients who received a standard prosthesis and those who received a high-flexion prosthesis had similar satisfaction with regard to pain and clinical outcome of surgery. Higher flexion did not have any correlation with overall patient satisfaction in several other studies. Moreover, no differences were found in average knee flexion between patients with high-flexion and standard TKAs. High-flexion devices may result in less polyethylene stress and lower patellar ligament strains, which may result in better function and long-term survivorship; however, the effects on patient satisfaction are unknown. Nashi and colleagues showed that patients with posterior-stabilized implants had better functional outcomes at 2 years.

Pain protocols

Various different protocols have been described to mitigate pain during and even after discharge after TKA. Spinal or general anesthesia is often supplemented with peripheral nerve blocks, including femoral nerve or adductor canal block, and sciatic nerve block. Various different pain cocktails have been injected or infused (such as steroidal and nonsteroidal medication, narcotics, and local anesthetics), and often these are supplemented with oral medication (such as cyclooxygenase-2 inhibitors, acetaminophen, and membrane stabilizing drugs). The aim is to minimize the adverse effects from the consumption of systemic and oral narcotics. There have been few prospective randomized studies to identify which pain cocktail is best; however, patients are distinctly more satisfied when their pain is controlled adequately after surgery.

Postoperative rehabilitation

Perioperative pain control, postoperative rehabilitation, and outcome/satisfaction after TKA are clearly linked. Patients with uncontrolled pain do not participate fully in their postoperative exercises, do not obtain maximal function, and therefore become dissatisfied with their operations. A structured postoperative exercise program seems to facilitate functional recovery. There is little evidence to support the use of continuous passive motion perioperatively; however, patients frequently request its use, although its effect remains controversial.

Hospital care

Patients who rate their hospital care highly have higher scores on their health-related quality of life up to 1 year after their surgery. This finding shows that immediate postoperative satisfaction (related to all aspects of patient care, not just the surgery) influences patient satisfaction. One good example of this is how changes in policy in Ontario, Canada, negatively influenced patient satisfaction after their second joint replacements. Changes reduced wait times, lengths of hospital stay, and physio-therapy access. Even though wait times for surgery were decreased overall, perceived wait time was still high, because patients calculated their wait times from the onset of illness until final treatment, as opposed to starting after the first surgical consultation. Some studies compared clinical outcomes for TKA performed in outpatient settings versus inpatient settings. Among them, only the work of Kolisek and colleagues assessed the satisfaction criterion. The investigators found no difference for satisfaction between outpatient and inpatient settings for TKA.

Postoperative care/length of hospital stay

Postoperative care during rehabilitation is also a key factor in patient satisfaction. In one study, patient satisfaction increased when continuous passive motion units were ready for patient use. In the same study, rehabilitation staff received specialized training in how to care for patients with joint replacements, which also led to a higher level of care. Patients were discharged 1 day earlier, and received 1 day less of postoperative care. In another study, patients who remained in the hospital longer after surgery were less satisfied, although it is difficult to pinpoint the exact cause of this dissatisfaction. Furthermore, postoperative performance is not always correlated with patient satisfaction. Often, happy patients and unhappy patients had similar clinical findings, performance tests, and radiographic results. Even if there was no need for revision surgery, unhappy patients continued to show more pain on the visual analog scale and hospital anxiety and depression scale.

Even different postoperative forms have varying effects on patients’ reported self-satisfaction. Patients reported higher levels of satisfaction when a change in the reporting mechanism was instituted, and this did not in reality reflect any significant change. Furthermore, when patients were asked open-ended questions regarding their satisfaction, the responses tended to be more negative compared with closed questions.