a Departamento de Ortopedia, Santa Casa de São Paulo, São Paulo, SP, Brasil
b Serviço de Ortopedia e Traumatologia, Hospital Israelita Albert Einstein, Universidade Federal de São Paulo (Unifesp), São Paulo, SP,Brasil
c Instituto de Ortopedia, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo (USP), São Paulo, SP, Brasil
d Escola Paulista de Medicina, Universidade Federal de São Paulo (Unifesp), São Paulo, SP, Brasil
Introduction
IntroductionDegenerative joint disease, or osteoarthrosis, is generally themain cause of physical deficiencies among elderly people.1The pain and functional limitation caused by this condition,especially in the lower limbs, present a strong correlation withreduced quality of life (QOL) among these individuals.1In thecase of degenerative knee arthropathy, total knee arthroplasty(TKA) is the preferred therapeutic option for cases of greaterseverity. This surgical procedure has been documented as verysatisfactory with regard to pain relief and restoration of jointfunction. This has led to greatly increased demand for this pro-cedure to be performed, with a consequent strong economicimpact.
The current methods for assessing the results from TKA arebased mainly on clinical signs and symptoms, physical exam-ination and radiographic evaluation. This type of assessmentdoes not take into account all aspects of the treatment, giventhat it is unable to detect patients' real needs and expecta-tions, such as changes to their QOL, social relationships andenvironment.
After achieving pain relief and restoration of joint functionduring the late postoperative period, patients tend to reassesstheir priorities. From then on, the way in which the surgicalresults have had a positive impact on patients' overall healthand function and on their QOL needs to be assessed. Recentstudies have shown that subjective factors affect the way inwhich individuals internalize their symptoms and functionalcapacity. Consequently, objective medical evaluation based onclinical and radiographic examination may be less importantthan the personal and individual idea that the treatment wassuccessful in providing the results that the patient himself orherself was expecting before the procedure.3-6
6The impact on QOL and satisfaction in relation to expecta-tions are gaining attention day by day as strong indicators forevaluating the results obtained subsequent to TKA. These twoparameters are the only ones capable of presenting the resultsfrom patients' own point of view. They also enable betterunderstanding of the real effects from the surgery, includ-ing physical and psychosocial benefits, which also should betaken into account in making decisions and in therapeuticmanagement. Studies on QOL have started to be conductedand to be valued because of the fundamental importance thatthey also have within the scope of public health and publicpolicies, and within the fields of health promotion and dis-ease prevention, as indicators for assessing the efficacy andimpact of treatments, especially those that have a high cost.
Many studies have revealed improvements in QOL amongpatients who have undergone TKA, but the variety of instru-ments and measurement intervals used, different scoringalgorithms and non-standardized presentations of resultshavealso led to challenges in attempting to understand theliterature on this topic. It also needs to be emphasized that thepresence of various confounding variables such as age, gender,physical health conditions, psychological factors, schoolinglevel, socioeconomic conditions, prior expectations and pres-ence of complications, among others, reveals that there is aneed for better comprehension of the real results provided byTKA regarding patients' QOL.7
This study had the aim of reviewing the literature on QOLamong patients who undergo TKA, with a view to defining theimpact of a variety of factors on the results and also definingwhich of them require better comprehension, in order to guidefuture studies on this subject.
Materials and methods
In order to survey the literature on this subject, the Medline,Embase, Lilacs and SciELO databases were searched using thefollowing terms: TKA (total knee arthroplasty); TKR (total kneereplacement); quality of life; and outcomes. The search wasrestricted to the English language and the last ten years. Thereference lists of the studies selected were also searched forother articles that possibly could be included.
No restrictions were imposed regarding study design.Nonetheless, most of the studies selected were prospectiveand observational. Studies that, in addition to TKA cases, alsoincluded data on patients who underwent total hip arthro-plasty (THA) were also accepted if they separated the kneeand hip cases in their analyses.
Articles that aimed to validate or compare questionnaires,evaluate revision surgery or nonsurgical treatment, or com-pare different prosthesis models, were excluded. Likewise,those dealing with other subjects that did not relate directlyto the objective of the systematic review were also excluded.
The articles selected through the search were read andevaluated by at least three of the present authors and wereaccepted through reaching a consensus. After inclusion, allthese studies were classified according to their level of evi-dence, using the system of the Center for Evidence-BasedMedicine (CEBM).
8The factors evaluated in the studies selected were ofmethodological nature, such as authorship, design, year,target population, sample, data-gathering instrument usedand main clinical outcomes. A critical assessment of theinstruments used, the factors that could have acted as con-founding variables and the likely relationship between QOLand patients' expectations.
The studies selected were presented descriptively in tablesand their data were analyzed in detail to construct a meta-analysis model. However, because of the methodologicalheterogeneity and the non-standardized form of presentation
of the effect size of the outcome variables, it was not possibleto sum the effects and proceed with construction of a meta-analysis model. Thus, the results were presented in the formof a systematic review, in order to show the main qualitativefindings from each study.
Results
ResultsFrom the search, 31 articles were selected: 28 observationaland three review articles (two systematic reviews and onenarrative review). Table 1 shows the classification of the arti-cles selected according to their level of scientific evidence andtype of design. Table 2 presents the main qualitative data ofthe observational studies selected. Table 3 presents the maincharacteristics of the review studies.
The SF-36 and/or SF-12 questionnaire was found in 20of the studies evaluated, as a generic QOL instrument. TheWOMAC questionnaire was used in 13 of the studies as a spe-cific instrument for QOL in osteoarthrosis. All the evaluationinstruments used are shown in Table 4.
Discussion
All the studies evaluated reported that the patients whounderwent TKA achieved improvement of their QOL. However,many factors were evaluated and different methods and pro-tocols were used. The studies also varied greatly in relation tothe length of the assessment period, going from short-term tolong-term analyses.
Most of the studies used a generic QOL questionnaire thataddressed general aspects of patients' physical, mental, psy-chological and social wellbeing. Another questionnaire wasalmost always used to assess physical and functional issues,specifically for patients with arthrosis. Some studies usednon-traditional questionnaires or questions for evaluatingindividuals' satisfaction regarding the surgery. This multiplic-ity of methods was a limiting factor and made it impossible toconduct standardized comparisons on the results from stud-ies.
Among the various factors evaluated that were associatedwith the concept of QOL, one of the factors most frequentlyseen was function. In an observational study, Gawel et al.9found that there was a significant improvement in knee func-tion among the patients when they used the leg for walking,going up stairs, standing and turning. These positive findingswere observed as early as in the fourth week of evalua-tion. However, Fitzgerald et al.10observed that, one monthafter the surgery, despite improvements in other respects,their patients presented significantly decreased physical func-tion, which increased their dependency on family support.Papakostidou et al.11observed that, six weeks after thesurgery, despite improvement in their patients' pain and reliefof their depressive states, function remained unsatisfactory.
Only in the assessment three months after the operation wasan improvement in the functional aspect of QOL observed,both through WOMAC and through KSS.
Gains in functional factors after the initial evaluation werealso observed in other studies. Kilic et al.12showed in eval-uations made after six weeks and six months using SF-36and KSCRS that there were significant improvements on allthe scales after six weeks. However, only the physical dimen-sion continued to improve significantly up to the end ofthe evaluation. In another study, it was observed that fromsix weeks after the operation until the end of the follow-up, there was a continual improvement in the dimensionsof physical function and emotional state, both in SF-36 andin WOMAC.13Improvement in dynamic balance also corre-lated positively with increased functional capacity and betterQOL.14
14Brandes et al.15observed that TKA provided profoundimprovement and excellent clinical results for most oftheir patients. Nonetheless, despite this improvement, manypatients do not reach the level of physical activity of healthypatients. The level of activity after the treatment seems to bemore influenced by the habit of practicing physical activitybefore the surgery than by the treatment itself.15
15With regard to pain, improvements have been observedin several studies.11,12,16-19The positive effects from surgerycan be observed as early as one,10four20or six11weeks afterthe operation and have been seen to last for up to sevenyears after the surgery.19The improvement in pain has aclose correlation with achieving better QOL scores, but if paincontinues to be present in postoperative assessments, thepossibility of attaining good results becomes lower.21Further-more, generalized preoperative pain that is unrelated to theknees has been found to negatively influence postoperativeQOL scores.19Social support10and practicing physical activitybefore the operation15,19have also been strongly associatedwith improvements both in pain and in joint function.
Sociodemographic factors that influence quality of life
Sociodemographic factors that influence quality of lifeAssociations between sociodemographic data and QOL weretested in the studies that were analyzed in this review.Regarding gender, according to Papakostidou et al.,11femalepatients presented lower scores in assessments conductedboth before the operation and six weeks afterwards. However,in another study that used SF-36 and KOOS, it was observedthat gender, age, axis, presence of other implants and preop-erative contractures did not significantly influence the painscores.22According to Rissanen et al.,18advanced age limitedthe gains, in evaluating the TKA results in terms of scoring.In another study, it was observed that both advanced age andpulmonary disease reduced the possibility of reaching satis-factory QOL.21
21In relation to other demographic factors, Papakostidouet al.11found that schooling level did not interfere with theQOL of patients undergoing TKA. Moreover, housing location,education level and social support were not predictors of QOLafter the surgery. In another study, conducted by Fitzgeraldet al.,10preoperative pain, physical function, demographiccharacteristics and social support presented significant cor-relations with improvement of pain and physical function.
Other points evaluated that improved through surgery andwere positively correlated with better QOL included edema,claudication20and sleep,18along with dynamic balance, whichcorrelated with improved mobility.14
14Obesity and postoperative complications have been associ-ated with worse scores in all the dimensions of WOMAC. Bothseparately and in combinations, they negatively influencedthe results in the initial assessments and also over the longterm, and they predicted poorer QOL for the patients.19Lowpostoperative WOMAC scores have been found in the presenceof severe obesity, with significant impairment regarding pain,stiffness and functional scores.23
23Reports of complications among patients have presentedhigh correlations with low QOL scores. Higher indicators andlower levels of comorbidities in patients' health after TKAcan be achieved through reducing or preventing complicationsduring the postoperative period.24Lingard et al.25reportedthat the most significant predictors of poor pain and functionscores from WOMAC and poor function scores from SF-36 werehigh numbers of comorbidities and low preoperative mentalhealth scores from SF-36.
The length of time spent waiting for surgery and its corre-lation with QOL were studied in some of the articles selected.Desmeules et al.26observed that a long wait for surgery hada significantly negative impact on pain, function and QOL.Another observational study divided the patients into fourgroups, depending on the length of their wait for surgery:< three months; three to six months; six to nine months;and > nine months.27In cases with a wait of more than sixmonths, there was a significant difference in QOL between thegroups in relation to pain in the contralateral knee. Patientswho had to wait for more than nine months presented theworst scores.27For example, McHugh et al.28observed wors-ened pain and function on the WOMAC scale, starting from await for surgery of three months.
More than half of the participants who were waiting forjoint replacement experienced deterioration of QOL duringthewaiting period. These data provide the necessary evidenceto guide healthcare professionals and public policymakers indrawing up care programs and allocating resources for indi-viduals who require surgery to replace this joint.29
Relationship between level of expectation, postoperativesatisfaction and quality of life
The preoperative level of expectation was not significantlyassociated with satisfaction with these expectations or withthe results obtained.30However, achievement of expectationswas highly correlated with the degree of satisfaction. Patientswho reported that their expectations had been met, at an eval-uation conducted 12 months after the surgery, also presenteda significantly greater gain in QOL.31
The patients had high expectations of benefits fromsurgery, especially with regard to pain relief, ability to walkand social interaction.31Those whose expectations wereachieved consequently had large gains in QOL. Gonzalezet al.31reported that health insurers should help their patientsto develop realistic expectations regarding the impact ofknee arthroplasty, so as to avoid frustration with the surgicalresults.
Through a multicenter observational study, Scott et al.32evaluated 1217 patients who underwent TKA and observedthat their expectations had a high correlation with sat-isfaction, one year after the surgery. They reported thatmanagement of patients' expectations and mental healthmight reduce their dissatisfaction. Nevertheless, the mostimportant predictor of dissatisfaction was pain-free totalarthroplasty.32
32Patients who were satisfied with the medical informationreceived regarding the surgery had high postoperative QOLscores. Satisfaction with the immediate care after surgeryis a good predictor of achievement of patients' expectationsone year after the surgery and is an important indicator forpatients' self-reported health.
Study perspectives
Our study has revealed that there is a need to standardize QOLscales, given that the existence of various health-related QOLinstruments has turned comprehension and comparison ofthe literature into a challenge. Standardization may improvethe use of information coming from this type of survey.
It can also be suggested, for future studies on this topic, thatassessments on patients' QOL should place value on broaderparameters than symptom control, reduction of mortality orincreased life expectancy.34,35Evaluations on patients under-going TKA cannot be limited to their conditions of health butmust include their feelings, expectations and behavior, espe-cially with regard to their functional abilities for activities ofdaily living.36-41
Conclusion
TKA is a procedure that is capable of providing an over-all improvement in patients' QOL. This improvement seemsto continue, even six months after the procedure. Pain and function are among the most important predictors ofimproved QOL, even when function remains inferior to that ofhealthy patients. Other factors that were positively correlatedwith better QOL after TKA included better dynamic balance,less claudication, better quality of sleep, physical activitypracticed before the procedure, adequate social and familialsupport and fulfillment of patients' expectations regarding theresults from the surgery. The factors that were negatively asso-ciated were obesity, advanced age, comorbidities, persistenceof pain after the procedure and waiting a long time for theoperation.
