<p><strong>Background: </strong>Total joint arthroplasty (TJA) is considered the treatment of choice to alleviate pain and improve function of patients with osteoarthritis. However,recent evidence suggests that a significant proportion of patients continue to report pain, or worsening of their symptoms well after their joint replacement. We call this chronic pain “<em>phantom joint pain</em>” as it persists despite the fact hat the affected joint has been replaced.</p> <p>Chronic pain of neuropathic origin may be a consequence of surgery or in patients with osteoarthritis (OA); there may be a combination of nociceptive and neuropathic pain (NP) mechanisms. As there are no definitive physiological indicators for NP or gold standards for diagnosis, Guidelines on Neuropathic Pain Assessment advocate the use of screening tools to evaluate the patient’s pain experiences and potentially characterize various pain features.</p> <p>Despite suggestions that phantom joint pain post TJA is a common problem there is limited information about its prevalence among Canadians. To date there are no studies that have characterized neuropathic vs. non- neuropathic chronic pain features in a TJA population.</p> <p><strong>Purpose: </strong>The purpose of this work was to determine the<em> </em>prevalence of chronic pain following total hip (THA) or knee (TKA) arthroplasty, and to identify the proportion of the cohort with chronic pain whose symptoms suggested the pain was of neuropathic origin. In addition we evaluated the ability of the NP Subscale of the McGill pain questionnaire [NP-MPQ (SF-2)] to identify individuals with NP vs. Non NP in the TJA population.</p> <p><strong>Methods:</strong> A retrospective cohort study (2-4 years post joint replacement) of 148 participants with primary unilateral TJAidentified from a large joint arthroplasty database (n=1143). Chronic pain was defined as post surgical pain reported 6-12 months following surgery to be 3 or higher (out of 5) on the Oxford Hip/Knee Scores, and that pain was the same or worse than reported preoperatively. A postal survey was used to administer the NP-MPQ (SF-2)and the Self-Administered Leeds Assessment of Neuropathic Signs and Symptoms (S–LANSS) (1.5-3.5 years post TJA). S-LANSS was the “non reference standard” for classification of neuropathic pain. Human research ethics approvals from Sunnybrook Health Sciences Centre and McMaster University/Hamilton Health Sciences were obtained prior to the study.</p> <p><strong>Results</strong>: The response rate to the postal survey to identify those with chronic pain of neuropathic origin was 53%. Thirteen percent of individuals experienced chronic pain; among individuals with chronic pain, neuropathic subtype was found in 28% (S-LANSS ≥ 12) - 43% [NP-MPQ (SF-2) ≥ 0.91]. Receiver Operating Characteristic (ROC) analysis for NP-MPQ (SF-2) yielded an area under the curve of 0.89 (95% CI: 0.82, 0.97). A cut off score of 0.91 NP-MPQ (SF-2),<strong> </strong>maximized sensitivity (89.5%) and specificity (75.0%). Our results revealed moderate correlation (r=0.56; 95% CI: 0.40, 0.68) between the S-LANSS and NP-MPQ (SF-2)scores in patients with NP post TJA.</p> <p><strong>Conclusion: </strong>Based on our results, a considerable percentage of individuals (13%) experience chronic pain following TKA and THA. Moreover, among individuals with chronic pain symptoms, a significant proportion (28-43%) of those experience pain that appears to have a neuropathic component, even 1.5 to 3.5 years following surgery.Overall prevalence of NP in TJA was 3.3 to 4.5%. The NP-MPQ (SF-2)subscale demonstrated “good” discriminatory ability, thus it might be useful in identifying patients with NP following TJA. Moderate association exists between the scales and this could affect prevalence rates in studies; or diagnosis of NP of individual patients based on the criterion used.</p> / Master of Science (MSc)

Résumé : Problématique: Près de 40% des 57 718 Canadiens ayant subi une arthroplastie du genou entre 2013 et 2014 étaient des travailleurs; la majorité étant âgée entre 55 à 64 ans. Des indices démographiques et législatifs laissent entrevoir que ce nombre continuera d’augmenter dans les prochaines années. Environ 15 à 30% de ces patients éprouvent des difficultés à reprendre ou à demeurer au travail six mois après la chirurgie. Malgré l’ampleur du phénomène, la perspective des travailleurs quant à ces difficultés demeure inconnue. Objectifs : Ce projet vise à mieux comprendre, selon la perspective du travailleur, les mécanismes sous-jacents à reprendre, ou non, une vie saine et active au travail à la suite d’une arthroplastie du genou. Plus précisément, il s’agit de décrire les représentations de l’incapacité au travail de ces travailleurs. Méthode : Ce projet qualitatif est basé sur une approche narrative avec comme cadre conceptuel le modèle d’autorégulation de Leventhal. Un échantillon de convenance de huit travailleurs ayant eu une arthroplastie du genou et éprouvant des difficultés à reprendre ou à demeurer au travail a été recruté. Des entrevues individuelles semi-dirigées ont été conduites. La méthode de Landry a été suivie pour le codage. D’abord, le cadre conceptuel a permis l’élaboration du cahier de codification tout en laissant la place à des codes émergents. Une analyse thématique des verbatim a ensuite été réalisée à l’aide du logiciel AtlasTi par deux codeurs indépendants (PM et MFC) qui ont discuté des codes divergents. Une fois toutes les entrevues codées, des réunions en équipe multidisciplinaire (kinésiologue, psychologue et physiothérapeute) ont eu lieu pour discuter de chaque cas et profiter de l’expertise de chacun des membres de l’équipe pour une analyse en profondeur. Résultats : La moitié des travailleurs rencontrée était absente du travail au moment de l’entrevue. L’émergence de cinq thèmes principaux a permis d’identifier deux cas types, soient retournés au travail avec difficultés, mais présence de soutien, et non retournés. Les travailleurs de la première trajectoire rapportent une implication de l’entreprise dans les démarches de retour au travail et ont les conditions nécessaires pour prendre des moyens actifs afin d’améliorer leur condition. Pour les travailleurs de la deuxième trajectoire, différents obstacles nuisent à la reprise des activités dont des complications postopératoires, une perception d’exigences de travail élevées, un faible soutien de l’environnement de travail et peu de ressources pour les aider. Conclusion : L’identification d’une trajectoire qui est moins favorable au retour au travail permet d’identifier les travailleurs à risque d’être en situation d’incapacité au travail. Ces travailleurs pourraient bénéficier de services en réadaptation au travail pour favoriser la reprise d’une vie saine et active après l’arthroplastie du genou. / Abstract : Purpose: Nearly 40% of the 57,718 Canadians who underwent total knee arthroplasty (TKA) between 2013 and 2014 were workers; the majority of them were aged from 55 to 64 years. Demographic and legislative indications suggest that this number will increase in the coming years. Actually, 15 to 30% of these patients report limitations at work or are not able to return to work six months after the surgery. Despite this growing phenomenon, workers’ insight on what influence work disability remains unknown. Objectives: The purpose of this study is to understand the worker’s perspective on what contributes or impedes the return to an active working life after TKA. Specifically, we aimed to document workers’ representations of their disability following TKA. Method: This qualitative study was conducted based on a narrative approach using Leventhal’s Common Sense Model (CSM) as the conceptual framework. A convenience sample of eight workers experiencing limitations while at work or being fully disabled (on sick leave) after TKA was interviewed. We conducted semistructured interviews, and then we followed Landry’s method for coding. First, we used a mixed coding method whereby codes were established a priori using the CSM with the possibility for emergent codes. Second, two researchers (PM and MFC) independently coded all interviews, compared the codes, and discussed diverging results. Third, after coding all interviews and based on the coding, content analysis was performed in multidisciplinary team (psychologist, physiotherapist, kinesiologist). Each interview was discussed by the team to compare the analysis and to obtain consensus as we believe our disciplinary backgrounds might impact interpretation of the data by bringing new information to the case. Content analysis was performed with Atlas-Ti software. Results: Half of the workers were fully disabled because of TKA. We identified two typical cases: workers who returned to work with difficulties but perceived support from their environment and workers who did not returned to work. The workers that returned to work reported involvement of their work environment in the return-to-work process. They felt they had greater improvement after TKA, and this enables them to further improve their condition. Workers who did not return to work encountered various obstacles such as ostoperative complications, a more physically-demanding job, negligible support from their work environment, and few resources to help them. Conclusion: The identification of a case that is less favorable to return to work allowed us to identify workers at risk of work disability. These workers could benefit from work rehabilitation services in order to promote a better active working life after TKA.

Local infiltration analgesia (LIA) is a new technique for postoperative pain management following knee arthroplasty. LIA involves a long-acting local anesthetic (ropivacaine), a non-steroid anti-inflammatory drug (ketorolac) and epinephrine infiltrated into the knee joint during surgery and injected postoperatively via a catheter. In the first two studies, LIA was compared with placebo in unicompartmental (I) and total (II) knee arthroplasty. Postoperative pain levels, morphine consumption and the incidence of side effects were lower in the LIA groups. In addition, we found a shorter length of hospital stay in the LIA group following unicompartmental knee arthroplasty compared with placebo (I), while the time to home readiness was shorter in the LIA group following total knee arthroplasty (II). In this study, we found that the unbound venous blood concentration of ropivacaine was below systemic toxic blood concentrations in a sub-group of patients. In the third study, LIA was compared with intrathecal morphine for postoperative pain relief following total knee arthroplasty (III). Pain scores and morphine consumption were lower, length of hospital stay was shorter and patient satisfaction was higher in the LIA group. In the final study, we investigated the effect of minimally invasive surgery (MIS) compared with conventional surgery in unicompartmental knee arthroplasty (IV). Both groups received LIA. We found no statistically significant differences in postoperative pain, morphine consumption, knee function, home readiness, hospital stay or patient satisfaction. In conclusion, LIA provided better postoperative pain relief and earlier mobilization than placebo, both in unicompartmental and total knee arthroplasty. When compared to intrathecal morphine, LIA also resulted in improved postoperative pain relief and earlier mobilization. Minimally invasive surgery did not improve outcomes after unicompartmental knee arthroplasty, when both groups received LIA.

Thesis (MScEng (Mechanical and Mechatronic Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: The c2 goodness-of-fit (GOF) test was used to determine which standard femoral component would achieve the best geometrical fit for a specific patient. This was done by creating 3D models from computerized tomography scan data through computer segmentation using Materialise MIMICS. The second step was to measure the morphological dimensions of the distal femur whereof twelve were selected and compared to the dimensions of two commercial femoral prosthesis designs. Thirdly, cadaveric femurs were scanned with a 3D desktop scanner to create a database with the dimensions of healthy knees. The 3D model database of the cadaveric femurs included cartilage layer. A cartilage thickness was added to the CT knee dimensions using a self-organizing map (SOM) calculation based on the healthy knee database. The developed method calculated alignment angles with higher accuracy than presently used and determined preoperatively which size to implant. Kinematic simulations of total knee arthroplasty (TKA) knees were compared to normal knee simulations created in LifeMOD. The articulating surface was the only variable changed between the two simulations and the kinematics of different sizes were evaluated. A method was created to scale the femoral component using the standard available sizes. The completed project will be used as foundation for customization of TKA prostheses. / AFRIKAANSE OPSOMMING: Die c2 graad van passing toets metode was gebruik om te bereken watter standaard femorale komponent ’n patiënt die beste geometries pas. Dit was gedoen deur eerstens 3D modelle gemaak vanaf CT skandeer data deur rekenaar segmentasie met Materialise MIMICS. Daarna was morfologiese dimensies gemeet vanaf die distale femur, waarvan twaalf gekies en vergelyk was teen two kommersiële femorale prostesis ontwerpe. Laastens was kadawer femurs geskandeer met ‘n 3D skandeerder om ’n databasis van gesonde knieë te maak. Die 3D modelle van die kadawer bene het die kraakbeen laag bevat. Die kraakbeen dikte was by die CT knie dimensies gevoeg d.m.v. SOM en die gesonde knie databasis. Die nuwe metode bereken die belynings hoeke met hoër akkuraatheid as wat huidiglik gebruik word en bereken voor die operasie watter grote om te gebruik. Kinematiese simulasies van knie prostesis was vergelyk met ’n normale knie simulasies gemaak in LifeMOD. Die artikulêre oppervlakte was die enigste veranderlike tussen die twee simulasies en kinematika van verskillende grotes was ondersoek. ‘n Metode was geskep om die standaard femorale komponent se skaal te verander vir ’n beter passing.

Aseptic loosening of the tibial component is an important cause of failure after total knee arthroplasty. Bone destruction often claimed to be caused by the cement makes the revision difficult. In order to treat younger patients, uncemented fixation has been introduced, but the etiology to loosening is multifactorial and only partly known. Early detection of implant migration facilitates research in this field but is difficult using conventional techniques. In this study modified versions of roentgen stereophotogrammetric analysis (RSA) were developed to obtain accurate and standardized evaluations facilitating comparison between prosthetic designs. The method was used to record the efficacy of cemented and uncemented fixation of different designs of the tibial component, to determine the accuracy of scintimetry in the detection of early aseptic loosening, and to analyse the in vivo kinematics of knee arthroplasties with different design and stability between the joint surfaces. Forty-three arthroplasties with comparatively high inherent stability of the joint surfaces were randomized to cemented or uncemented fixation of the tibial component. In all groups micromovements were rather large, but with no differences between the cemented and uncemented components. The preoperative diagnosis (arthrosis OA, n=25; rheumatoid arthritis RA, n=18) did not influence the magnitude of micromotion. 20 arthroplasties with the same design as above but equipped with an intramedullary stem, were randomized to cemented or uncemented fixation in patients with RA. Cement improved the fixation. Uncemented stemmed components displayed micromovements seemingly larger than unstemmed ones. 34 arthroplasties with an unconstrained design of the joint area and fixed to the tibia with four pegs were randomized to cemented or uncemented fixation in patients with OA. When used uncemented 4 screws were added. Compared with previously investigated designs small micromotions were recorded, and especially in the cemented cases. Uncemented components with thin polyethylene inserts displayed larger initial micromotions. The preoperative deformity influenced the direction of the micromotion. 33 knees were followed prospectively with RSA and scintimetry to evaluate any correlation between these methods. Low activity under the tibial component at 2 years implied prosthetic stability, whereas high activity indicated instability or high bone remodelling caused by the preoperative malalignment. The in vivo kinematics in three different designs of knee arthroplasties were analyzed during active flexion and extension without weight-bearing. Each type of prosthesis displayed design-specific abnormalities when compared with a normal material. Pronounced posterior tibial translations were recorded during flexion regardless whether the posterior cruciate ligament had been sacrificed or not. Data from the kinematic and the fixation studies suggest that movements restricted by the design of the joint area are transmitted to the bony interface with design-specific micromotions as the result. Analysis of knee joint kinematics during extension and weight-bearing revealed small alterations compared with non-weight-bearing. Evaluation of the three-dimensional movements in terms of helical axis rotations and translations confirmed the constrained or unconstrained in vivo behaviour of the designs under study. This analysis also facilitated the interpretation of the kinematic behaviour of the prosthetic knees and may be of value in the evaluation of new designs. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 1992, härtill 7 uppsatser.</p> / digitalisering@umu

The overall aim of this thesis was to evaluate methods for urinary catheter handling in patients undergoing hip surgery. The intention was to gain knowledge in order to provide optimal and cost- effective care regarding urinary catheterisation in this group of patients. In Study I , 45 of the 86 catheterised patients (52%) contracted nosocomial urinary tract infections (UTIs). Diabetes was a risk factor for developing UTI, and cloxacillin as a perioperative antibiotic prophylaxis seemed to offer a certain protection. Study II was a randomised controlled trial on the effect of clamping (n = 55) or not (n = 58) of the indwelling urinary catheter before removal. No significant differences were found between the groups with respect to time to normal bladder function, need for recatheterisation, or length of hospital stay. Study III was a randomised controlled trial among patients with hip fracture and hip arthroplasty, in which the patients were randomised to intermittent (n = 85) or indwelling (n = 85) urinary catheterisation. No significant differences in nosocomial UTIs (9% vs. 12%) or cost-effectiveness were shown. The patients in the intermittent group regained normal bladder function significantly sooner after surgery. Fourteen percent of the patients in the intermittent group did not need any catheterisation. In Study IV , 30 patients were interviewed about their experiences of bladder emptying and urinary catheterisation. The patients’ views were described through the main category ‘An issue but of varying impact’. Both bladder emptying through micturition and bladder emptying through catheterisation were described as convenient, but also as uncomfortable and an intrusion on dignity. The patients were aware of risks and complications of urinary catheterisation. In conclusion, this thesis indicates that UTI is common in hip surgery patients. Clamping of indwelling catheters seems not necessary. There is no preference for either intermittent or indwelling urinary catheterisation according to the results of this thesis, either for the development of nosocomial UTI or, for cost-effectiveness, or from the patient perspective. Nurses should be aware that catheterisation might make the patients feel exposed, and it is essential that their practice reflect the best available evidence.

This study concerned the development and validation of a hardware and software biomeasurement system, which was designed to be used by physiotherapists, general practitioners and other healthcare professionals. The purpose of the system is to detect and assess gait deviation in the form of reduced post-operative range of movement (ROM) of the replacement hip joint in total hip arthroplasty (THA) patients. In so doing, the following original work is presented: Production of a wearable, microcontroller-equipped system which was able to wirelessly relay accelerometer sensor data of the subject’s key hip-position parameters to a host computer, which logs the data for later analysis. Development of an artificial neural network is also reported, which was produced to process the sensor data and output assessment of the subject’s hip ROM in the flexion/extension and abduction/adduction rotations (forward and backward swing and outward and inward movement of the hip respectively). The review of literature in the area of biomeasurement devices is also presented. A major data collection was carried out using twenty-one THA patients, where the device output was compared to the output of a Vicon motion analysis system which is considered the ‘gold standard’ in clinical gait analysis. The Vicon system was used to show that the device developed did not itself affect the patient’s hip, knee or ankle gait cycle parameters when in use, and produced measurement of hip flexion/extension and abduction/adduction closely approximating those of the Vicon system. In patients who had gait deviations manifesting in reduced ROM of these hip parameters, it was demonstrated that the device was able to detect and assess the severity of these excursions accurately. The results of the study substantiate that the system developed could be used as an aid for healthcare professionals in the following ways: · To objectively assess gait deviation in the form of reduced flexion/extension and abduction/adduction in the human hip, after replacement, · Monitoring of patient hip ROM post-operatively · Assist in the planning of gait rehabilitation strategies related to these hip parameters.

The number of patients electing to undergo total hip arthroplasty (THA) in the United States has been projected to double by the year 2030, with a growing number of these patients below the age of 65 years. This cohort of patients not only desires to return to pain free daily activity, but wishes to participate in recreation and sporting activities. However, many of these patients report pain, impairments, and functional limitations following THA. The number one deficit observed for patients who fail conventional post-operative rehabilitation is persistent weakness of the hip abductor muscles. In order to safely progress these patients back to their desired activity level, appropriate postoperative rehabilitation programs need to be developed. The primary objective of this dissertation was to examine the effectiveness of a hip abductor strengthening program on subjective and objective outcomes following THA. The secondary aims of this study were to document hip muscle activation and lower extremity movement patterns during functional exercises; and to compare shortterm subjective and objective clinical outcomes for subjects following THA compared to controls. Several observations were made from our results. First, the lunge, single leg squat, and step-up and over exercises may be appropriate to include in post-operative rehabilitation programs to transition THA subjects from static strengthening exercises to dynamic activities. Second, subjects at 6- and 12-weeks following THA continue to exhibit strength and functional deficits, which contributes to decreases in activity level. Third, the addition of an exercise program targeting the hip abductor muscles following THA may help to improve subjective and objective outcomes compared to conventional post-operative rehabilitation. Finally, findings from our results are summarized and we propose a model to develop patient-specific rehabilitation programs.

A disfunção da musculatura abdutora do quadril é uma preocupação entre aqueles que se utilizam da via de acesso lateral direta, descrita por Hardinge para a realização da artroplastia total do quadril (ATQ). Pouco se sabe se a sutura transóssea ou transtendínea da musculatura abdutora do quadril influenciam no resultado funcional da ATQ. Quantificar a força da musculatura abdutora, nos pacientes operados, é de grande importância, já que os resultados obtidos poderão nortear o melhor tipo de reinserção desta musculatura. Avaliamos de forma prospectiva e randomizada 32 pacientes com o objetivo de quantificar através de análise isométrica o desempenho da musculatura abdutora do quadril no pósoperatório de ATQ, comparando a reinserção da massa muscular por suturas transósseas (TO) e transtendíneas (TT) utilizando um dinamômetro Biodex System IV Pro® (Biodex Medical System, Shirley, NY, USA) no pré-operatório, no terceiro e sexto meses pós ATQ. Adicionalmente, avaliamos o efeito da sutura transóssea e transtendínea no resultado funcional da ATQ segundo o escore de quadril de Harris (HHS) e correlacionamos a medida do torque abdutor com o HHS no sexto mês de pós-operatório de ATQ. Após análise estatística não houve diferenças entre o tipo de sutura e o torque abdutor nos diferentes tempos, e tampouco entre o tipo de sutura e o resultado funcional segundo o HHS. Por fim, o valor do HHS apresentou correlação desprezível com o valor do torque da musculatura abdutora. Nossos resultados sugerem que não há superioridade de um tipo de sutura em relação ao outro quanto ao desempenho abdutor ou resultado funcional da ATQ. / Dysfunction of the hip abductor muscles is a concern among those using the direct lateral approach described by Hardinge for total hip arthroplasty (THA). It is not known whether the transosseous or the transtendineous sutures of the abductor muscles may influence the functional outcome of the THA. To quantify the strength of the abductor muscles in the operated patients is of great relevance, since these results could guide the best type of reinsertion of this musculature. We evaluated prospectively and randomly 32 patients with the purpose of quantifying the performance of hip abductor muscles after the THA using isometric analysis, comparing the reinsertion of the muscle mass by transosseous (TO) and transtendineous (TT) sutures using a Biodex System IV Pro® dynamometer (Biodex Medical System, Shirley, NY, USA) in the pre-operative period, and three and six months after THA. In addition, we evaluated the effect of transosseous and transtendineous sutures on the functional outcome of THA according to the Harris hip score (HHS) and correlated the abductor torque with the HHS in the sixth postoperative month of THA. After statistical analysis there were no differences between the type of suture and the abductor torque at different times, nor between the type of suture and the functional result according to the HHS. Finally, the HHS value presented negligible correlation with the torque value of the abductor muscles. Our results suggest that there is no superiority of one type of suture over the other in relation to abductor performance or functional outcome of the THA.

A avaliação funcional após a artroplastia total de joelho (ATJ) tem o intuito de analisar como os resultados alcançados após a cirurgia impactam na qualidade de vida e função dos pacientes. Questionários subjetivos de auto percepção da função são os instrumentos mais utilizados, porém, tendem a superestimar a função física. Os testes de desempenho físico avaliam objetivamente o que o indivíduo é capaz de executar, mas avaliam tarefas isoladas que nem sempre refletem a mobilidade nas atividades de vida diária. Portanto, o objetivo deste estudo foi analisar o quanto a avaliação funcional, que incluiu questionários subjetivos e testes de desempenho físico, permite avaliar as mudanças ocorridas longitudinalmente após a ATJ e permite estabelecer fatores pré e pós-operatórios preditivos da função após um ano de cirurgia. Foi realizado estudo longitudinal prospectivo com 87 sujeitos (62 mulheres), idade 67±7 anos, IMC 33±5 kg/m2, submetidos à ATJ primária unilateral. A avaliação ocorreu no pré-operatório e 3, 6 e 12 meses após a cirurgia. Análise da covariância analisou as mudanças ao longo do tempo e a árvore de classificação e regressão estabeleceu os fatores preditivos. O questionário subjetivo WOMAC-função e os testes de desempenho físico timed up and go (TUG) e teste de caminhada de seis minutos (TC6) aos 12 meses de pós-operatório foram as variáveis primárias. A idade, índice de massa corpórea (IMC), WOMAC-dor, função pré-operatória e força muscular do joelho operado e não operado, tanto pré quanto pós-operatoriamente, foram estabelecidas como variáveis secundárias. Os resultados mostraram que WOMAC e o TUG atingiram platô de evolução aos três meses de pós-operatório, enquanto oTC6 alcançou o platô aos seis meses de pós-operatório. Com relação aos fatores pré- operatórios preditivos da função após 12 meses de cirurgia, indivíduos com TUG <=19 s e idade entre 62 e 70 anos alcançaram melhor pontuação no WOMAC-função. Sujeitos com força dos músculos extensores do joelho não operado >=99 Nm/kg e TC6 >328 m antes da cirurgia percorreram maior distância no TC6. Sujeitos com TUG =421 m no pré-operatório obtiveram melhor desempenho no TUG. Sobre os fatores pós-operatórios preditivos da função, sujeitos com WOMAC-dor < 1,5 pontos, TC6 >=410 m e TUG < 8 s apresentaram melhor pontuação do WOMAC-função. Sujeitos com TUG <9 s e força dos músculos extensores do joelho operado >=113 Nm/kg apresentaram melhor desempenho no TC6. Sujeitos com TC6 >=421 m e força dos músculos flexores do joelho não operado >=47Nm/kg foram mais rápidos na execução do TUG. Concluímos que os questionários subjetivos e os testes de desempenho físico apresentaram diferentes comportamentos de evolução ao longo de um ano de pós-operatório de ATJ. Sujeitos com melhor desempenho físico pré e pós-operatório apresentam melhor pontuação no WOMAC-função após a cirurgia e sujeitos com pior dor pós-operatória apresentaram pior percepção da função no mesmo período. Os fatores de maior predição dos testes de desempenho físico foram a função pré-operatória e a força muscular pré e pós-operatória. / The functional evaluation after total knee arthroplasty (TKA) is intended to analyze how the results achieved by the surgery affect the quality of life and function of patients. Subjective patient-report outcomes measures are the most commonly used instruments, but tend to overestimate physical function. Physical performance tests objectively evaluate what the individual is capable to perform, but evaluate isolated tasks that do not always reflect mobility in activities of daily living. Therefore, this study was aimed to analyze how functional evaluation, which encompassed subjective questionnaires and physical performance tests, enables us to evaluate the changes occurred longitudinally after TKA and to establish pre and post-operative predictive factors of this function one year after surgery. We performed a prospective longitudinal study with 87 individuals (62 women), age 66.9±6.66 years, BMI 32.5±5 kg/m2, submitted to unilateral primary TKA. The evaluation took place in the pre-operative period and 3, 6 and 12 months after surgery. The analysis of covariance assessed the changes over time, whereas the classification and regression tree established the predictive factors by considering the WOMAC-function questionnaire and the physical performance tests Timed Up and Go (TUG) and Six-minute Walk Test (6MWT) at 12 months post-operative as primary variables. Age, body mass index (BMI), WOMACpain, pre-operative function, and knee muscle strength, both pre-operatively and postoperatively, were set up as secondary variables. The results showed that the subjective questionnaires and the TUG tests reached a plateau of evolution at three months post-operative, while the 6MWT tests reached the plateau at six months postoperative. Regarding the pre-operative predictive factors of the function at 12 months after surgery, individuals with TUG<=19.3 seconds, aged between 62 and 70 years achieved a better score in the WOMAC-function one year after surgery. Individuals with non-operated knee extensor muscle strength >=99.43 Nm/kg and 6MWT >328 meters before surgery walked a longer distance in the 6MWT test. Individuals with TUG <12.3 seconds and 6MWT>=421 meters in the pre-operative period achieved better TUG performance. As for the post-operative predictive factors of the function, individuals with WOMAC-pain<1.5 points, 6MWT>=410.2 meters and TUG <7.90 seconds showed better scores of the WOMAC-function. Individuals with TUG<9.44seconds and operated knee extensor muscle strength>=112.8 Nm/kg showed better performance in the 6MWT test. Individuals with 6MWT>=421 meters and non-operated knee flexor strength>=47 Nm/kg were faster in executing the TUG test. We concluded that the subjective questionnaires and the physical performance tests showed different evolutionary behaviors during the first year after the TKA surgery. Individuals with better pre and post-operative physical performance show better scores in the WOMAC-function after surgery, while individuals with worse post-operative pain show worse perception of the function in the same period. The most predictive factors of the physical performance tests were pre-operative function and pre and post-operative muscle strength.