Introduction: Knee osteoarthritis is one of the common causes leading to musculoskeletal disability of the elderly around the world. Total knee replacement (TKR) is an effective and common treatment for end stage knee arthritis. Most papers suggest that early rehabilitation could improve postoperative knee function. However, postoperative pain and local swelling are the complications that diminish range of motion (ROM) and inhibit patients’ recovery. A comprehensive review of the literature reveals that cryotherapy is an effective and safe method to overcome these complications. In this paper, a guideline of using cryotherapy in reducing postoperative pain and knee swelling so as to improve the ROM of patients and promote recovery after TKR has been developed. Objectives: The objectives of this translational research are: (1) to look for relevant papers that related to cryotherapy in reducing postoperative pain and knee swelling so as to improve the ROM of patients after TKR; (2) to gather and criticize the data obtained; (3) to develop a guideline of using cryotherapy in reducing pain, knee swelling and improving ROM of patients after TKR based on the evidence from the reviewed literature; (4) to assess the implementation potential of the newly developed guidelines; and (5) to establish the implementation and evaluation plans for the new innovation. Methods: An empirical literature search published from 2001 to 2011 by several searching engines regarding cryotherapy in reducing postoperative pain and knee swelling with the aim to improve the ROM of patients after TKR has been conducted. After that, the qualities of relevant studies were retrieved and criticized by using the appraisal checklist of the SIGN (2004). The derived evidences were then be summarized and synthesized. An evidence-based guideline was established with reference to the evidence from the reviewed literatures and the results of the quality assessment. Recommendations are graded by SIGN (2004). The implementation potential including transferability, feasibility and cost-benefit ratio of the innovation were assessed as well. Lastly, implementation and evaluation plans have been developed to assess and appraise the effectiveness of the new guideline. Results: Finally, seven studies were chosen as final references after methodological quality assessment. Four main types of comparison were made from these seven reviews including: (1) continuous compressive cryotherapy vs. compressive crepe bandage; (2) comparison in different temperature of cryotherapy; (3) outcome measures; and (4) complications in cryotherapy. After the summary, six main categories of recommendations were synthesized: (1) continuous compression cryotherapy; (2) effective temperature; (3) potential complications; (4) regular assessment; (5) duration; and (6) intermitted ice pack regimen. Based on these syntheses and recommendations, a guideline of using cryotherapy for patients after having TKR was developed. Conclusion: With the implementation of the newly developed evidence-based cryotherapy guidelines for patients after having TKR in local clinical settings, the improvement in the ROM of the knee joint will be anticipated as a result of the reduction in postoperative pain and knee swelling. / published_or_final_version / Nursing Studies / Master / Master of Nursing

Total knee replacement is the gold standard treatment for restoring mobility and relieving pain associated with osteoarthritis when other medical therapy has failed. Revision surgery is necessary when the replaced knee fails, which is often a result of implant damage (such as wear) or poor kinematics. Design optimization is a method for finding the best shape for a component using an optimization approach considering one or multiple performance metrics. The shape of a parametric candidate design can be manipulated by an optimization algorithm, which seeks to minimize an objective function subject to performance constraints and design space limitations. During multiobjective design optimization, multiple performance measures are minimized simultaneously, the relative importance of each determined using a weighted sum. This approach can also be used to derive a Pareto curve or frontier which graphically describes the relationships (or trade-offs) between the performance measures. It was hypothesized that a trade-off exists between wear and kinematics performance in total knee replacements. The objective of this research was to test this hypothesis by using multiobjective design optimization to describe this relationship with a Pareto curve. It was first necessary to develop and validate numerical frameworks for wear and kinematics simulations, using models constructed using a parametric modeller. The Pareto curve was then generated using a combination of single objective and multiobjective design optimizations considering these two performance measures. Single objective optimization for wear yielded a theoretical design with superior wear resistance when compared to a typical commercially available knee design. Single objective optimization for kinematics yielded a theoretical design capable of higher flexion, as well as more natural laxity characteristics. After performing multiobjective design optimization, the resulting Pareto curve showed that there is, in fact, a trade-off between wear and kinematics performance. When considering optimum designs, in order to improve the wear performance it was necessary to sacrifice kinematics performance, and vice-versa. This previously suspected but never verified nor quantified relationship can be used to improve total knee replacement designs, as well as help healthcare providers select the best implants for their patients. / Thesis (Ph.D, Mechanical and Materials Engineering) -- Queen's University, 2010-04-14 13:43:42.639

The purpose of this study was to determine the effectiveness of the Augmented Soft Tissue Mobilization (A.S.T.M.) Rehabilitation Technique on total knee replacement patients. The specific measurements assessed were stride length (SL), stride frequency (SF), walking velocity, support time (ST), total time (TT), static and walking range of motion (ROM) of the hip, knee, and ankle, ground reaction forces (GRF), and torques. Fourteen subjects (Female = 7, Male = 7) completed the study. Subjects were randomly assigned to two experimental groups, the Traditional Therapy treatment or the A.S.T.M. treatment. There were five testing sessions: pre operation, 8 weeks, 12 weeks, 16 weeks, and 24 weeks post operation. On the 12 week test, the subject had completed their assigned of treatment protocol. Static ROM was derived from gonimetric measurements before each testing session. Stride length, stride frequency, velocity, time, and walking ROM were derived from accelerometer data. Statistical analysis using ANOVA revealed a significant change in all static ROM, SL, and ST. The data indicated that both groups of the Total Knee Replacement patients did improve their functional status from their status prior to surgery. In addition, the data indicated that the Augmented Soft Tissue Mobilization program and the Traditional Therapy program are equally acceptable rehabilitation techniques. / School of Physical Education

Background: Cryotherapy is commonly used during physiotherapeutic rehabilitation of patients following total knee replacement (TKR). Evidence for treatment effectiveness within the current literature is contradictory and there are no clinical guidelines to inform cryotherapy treatment within this particular patient group. This study surveys current cryotherapy treatment efficacy in the acute post-operative management of TKR patients. Methods: In total 263 senior physiotherapists completed and returned a postal questionnaire, which, using open and closed questions investigated the use of cryotherapy following TKR. Survey results were used to inform a pragmatic randomized clinical trial (RCT) involving 133 consecutive TKR patients. The RCT investigated cryotherapy treatment efficacy in the acute post-operative management of TKR patients. Patients were randomized into three groups; no cryotherapy (NC), delayed cryotherapy (DC) and immediate cryotherapy (IC). The primary outcome measure was post-operative pain with knee swelling, active range of motion (AROM), function and levels of physiotherapy input assessed as secondary outcome measures. Observations were taken pre-operatively and at 3, 7 and 42 days post-operatively. Results: The survey reported that 33% of respondents used some form of cryotherapy routinely following TKR surgery. The two main methods of cryotherapy application were Cryocuff (59%) and crushed ice (30%). Treatments were most frequently applied between 24 hrs and 48 hrs post-surgery for 20 minutes, twice a day. Chi square analysis indicated significant differences (p<0.01) in between NHS and private sites relating to a lack of cryotherapy resources and treatment time for cryotherapy in the NHS. A lack of proven efficacy was the most cited reason for not applying cryotherapy treatment, and swelling the most common treatment indicator. There was particular uncertainty regarding the cleaning and sterilization of the Cryocuff device. The RCT indicated that patients in IC group had significantly less post-operative pain than the NC and DC groups at 3 days. Mean difference (p <0.05, 95% CI) in post-operative analogue scores (VAS, scale 0-10) was -1.6 (p <0.01, CI -2.49- to -0.707) for IC and NC; and -0.922 (p= 0.044, CI -0.183 to -0.009) for IC and DC groups. At 7 and 42 days there were significant reductions in VAS scores for both cryotherapy groups compared to the NC group. There was significant improvement in knee swelling, AROM, ability to transfer and need for additional physiotherapy in both cryotherapy treatment groups although no significant reduction in opiate requirement was found. Conclusions: In current clinical practice there was little consensus regarding treatment indicators, method of application and management of cryotherapy following TKR. However, in a RCT the use of cryotherapy combined with compression, as compared to a no cryotherapy control, led to significant reductions in patient reported pain, less post-operative swelling, greater recovery of AROM, faster return of function and less reliance on OPD physiotherapy treatment. It is concluded that cryotherapy combined with compression has an important role to play in the acute rehabilitation of TKR and should be considered as part of routine management.

A osteoartrite de joelho caracteriza-se por um processo degenerativo da cartilagem articular e do osso subcondral, com a presença de processo inflamatório, dor, rigidez, fraqueza muscular, e que leva a uma incapacidade funcional. É uma doença degenerativa e incapacitante, e que necessita de reabilitação funcional para a melhora do indivíduo. Nos casos mais avançados, pode ser realizada a substituição da articulação degenerada por uma prótese. A cirurgia de artroplastia total de joelho pode levar o indivíduo a uma melhora funcional (redução da dor, com conseqüente melhora da capacidade de ativação do quadríceps por redução da inibição muscular reflexa, e possivelmente aumento na capacidade de produção de força do músculo) e a uma melhora da qualidade de vida. Em função disso o objetivo do presente estudo foi comparar as razões de torque e de ativação muscular dos flexores e extensores do joelho e a qualidade de vida e a dor entre indivíduos com osteoartrite de joelho (n=20) e indivíduos com artroplastia total de joelho (n=13). As razões de torque e de ativação dos músculos flexores e extensores de joelho foram avaliados durante contrações isométricas voluntárias máximas no ângulo de 60º, e contrações isocinéticas concêntricas e excêntricas nas velocidades de 60º/s e 180º/s. As razões de torque foram calculas a partir da divisão do valor do pico de torque flexor pelo extensor, e as razões de ativação da mesma forma, porém pela divisão do valor RMS do sinal EMG do músculo BF pelo valor RMS (Root Mean Square) dos músculos VL, RF e VM. As razões musculares foram comparadas entre os grupos e correlacionadas com o questionário Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Os escores do WOMAC e a dor (obtida através da escala visual analógica de dor) foram comparados entre os dois grupos. O grupo artroplastia obteve menores escores no WOMAC quando comparado ao grupo osteoartrite (p=0,022), o que indica melhora da qualidade de vida após a artroplastia total de joelho. O grupo artroplastia também apresentou menor intensidade de dor que o grupo osteoartrite (p=0,014). Tanto as razões de torque quanto as de ativação foram semelhantes entre os grupos. Uma correlação positiva foi encontrada entre as razões de torque isocinético convencional e o WOMAC para o grupo osteoartrite, nas velocidades de 60º/s (r=0,501 p=0,025) e 180º/s (r=0,863 p=0,0001). Isso demonstra que indivíduos com aumento das razões de torque, ou seja, maiores desequilíbrios musculares, apresentaram piora da qualidade de vida. Os resultados deste estudo apoiam a hipótese de que a técnica cirúrgica de artroplastia total de joelho propicia uma redução da dor e uma melhora da qualidade de vida. No entanto, não produz uma melhora na funcionalidade do sistema neuromuscular conforme demonstrou a análise das razões de torque e de ativação dos músculos flexores e extensores do joelho. / The knee osteoarthritis is characterized by a degenerative process of the joint cartilage and of the subcondral bone, with an inflammatory process, pain, joint stiffness, muscular weakness, leading to functional incapacity. It is a degenerative disease, which incapacitates the individual and needs functional rehabilitation. In the most advanced cases, the replacement of the joint is accomplished by the surgical implantation of a prosthesis. The total knee replacement surgery leads the patient to functional improvement (reduction of the pain, increasing muscle force production capacity, and possibly improvement the muscle unbalance) and an improvement of the quality of life. Therefore, the purpose of this study was to compare the muscle torque ratios and the activation ratios of the knee flexor and extensor muscles, as well as the quality of life and the pain intensity amongst patients with knee osteoarthritis (n =20) and patients with total knee replacement (n =13). The torque and activation ratios of the flexor and extensor muscles were evaluated during maximal voluntary isometric contractions at a knee joint angle of 60º, and during maximal voluntary isokinetic contractions (concentric and eccentric) at the angular velocities of 60º/s and 180º/s. The torque ratios were calculated by dividing the maximal peak torque value of the knee flexor muscles by the corresponding knee extensors torque value. The activation ratios were calculated in a similar way, by dividing the RMS values of the biceps femoris muscle by the RMS (Root Mean Square) values of the knee extensor muscles (i.e. vastus lateralis, rectus femoris and vastus medialis). All ratios (torque and activation) were compared between the two groups and correlated with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire. The activation ratios showed a similar behavior as the torque ratios for all four muscles studied, and there was no difference for these ratios between the two groups. The WOMAC scores and the pain scores (obtained by the pain visual analog scale) were compared between the two groups. The total knee replacement group obtained smaller scores in WOMAC when compared to the osteoarthritis group (p =0,022). This indicates improvement in the quality of life after the total knee replacement surgery. Patients from the total knee replacement group also presented smaller pain than the osteoarthritis group (p =0,014). A positive correlation was observed between the conventional isokinetic torque ratios and the WOMAC for the osteoarthritis group at the angular velocities of 60º/s (r=0,501 p =0,025) and 180º/s (r =0,863 p =0,0001). This indicates that patients with increased torque ratios, or in other words larger muscular unbalances, also present worsening of the quality of life. The results here presented support the idea that the total knee replacement produces a reduction in pain and an improvement in the quality of life. However, it does not improve the knee functionality as the torque and activation ratios of the knee flexor and extensor muscles was similar between the two groups.

A osteoartrite é uma desordem articular comum nos idosos, sendo responsável por causar perda da funcionalidade destes indivíduos, quando comparada a outras doenças. Sua prevalência aumenta com a idade por ser uma doença irreversível. Esta condição musculoesquelética causa dor, incapacidade física e redução da qualidade de vida. A artroplastia total de joelho é o procedimento adequado para o tratamento da osteoartrite em seus graus mais avançados, e tem apresentado uma melhora funcional dos extensores do joelho (por meio da redução da inibição reflexa e possível aumento da capacidade de produção de força) e da qualidade de vida (pela redução da dor, aumento da mobilidade e retorno às atividades de vida diárias) nesses casos avançados da doença. No entanto, os efeitos da substituição do joelho osteoartrítico pela prótese não são totalmente conhecidos. Em função disso, o objetivo do presente estudo foi comparar a ativação muscular e a produção de força (torque) de indivíduos com osteoartrite (n=20) e indivíduos com artroplastia total de joelho (n=12). O pico de torque dos músculos extensores de joelho foi avaliado durante contrações isométricas voluntárias máximas nos ângulos de 30º, 60º, 75º e 90º. Nos mesmos ângulos articulares também foi avaliada a ativação elétrica dos músculos vasto lateral, vasto medial e reto femoral, através da eletromiografia de superfície. A qualidade de vida foi comparada entre os dois grupos através do questionário WOMAC. O grupo artroplastia obteve menores escores no questionário, o que indica melhora da qualidade de vida destes indivíduos ao serem comparados com o grupo osteoartrite. O comportamento dos dados tanto para a produção de torque como para a ativação muscular, apresentou-se semelhante nos dois grupos. A produção de torque não apresentou diferença significativa entre os grupos avaliados (p=0,775), sendo que a única diferença observada foi para o torque entre os ângulos testados (p=0,0001). Assim como para a produção de torque, a ativação muscular não apresentou diferença significativa entre os grupos osteoartrite e artroplastia total de joelho para os músculos VL, RF e VM (p>0,05). Somente para o menor ângulo (30º) e para o maior ângulo (90º) houve diferença significativa da ativação muscular em relação aos ângulos para os músculos vasto lateral (p=0,011) e vasto medial (p=0,014). Os resultados apresentados neste estudo suportam a hipótese de que a técnica cirúrgica de artroplastia total de joelho propicia uma redução da dor e uma melhora da qualidade de vida. No entanto, essa melhora na qualidade de vida parece não ser refletida em uma melhora funcional após a colocação da prótese, uma vez que não foi observado um aumento na ativação muscular com um correspondente aumento na capacidade de produção de força dos músculos extensores do joelho. / Osteoarthritis is a degenerative disease prevalent in the elderly population characterized by pain, disability and decrease of quality of life. Total knee replacement is indicated for the last stages of the disease, and shows a functional improvement of the knee extensor muscles (by a reduction of reflex inhibition and possibly by increasing muscle force production capacity) and improvement of quality of life (by the reduction in pain, increase in mobility and return to daily life activities) in these advanced stages of the disease. However, the functional effects of the joint replacement are not completely understood. Therefore, the purpose of this study was to compare both the muscle activation and the force production (torque) developed by patients with osteoarthritis (n=20) and patients which underwent total knee replacement (n=12). The knee extensor muscles peak torque was evaluated during maximal voluntary isometric contractions at the joint angles of 30º, 60º, 75º and 90º of knee extension. At the same joint angles the electrical activation was obtained, by surface electromyography from the vastus lateralis, the vastus medialis and the rectus femoris muscles. The WOMAC questionnaire was used to compare the quality of life between the two groups of the study. The arthroplasty group showed lower scores, indicating an improvement in the quality of life compare to the osteoarthritis group. Both groups showed a similar behavior in the torque production and in the muscle activation. Torque production was similar between the two groups (p=0,775), although there was a difference in the torque amongst the studied angles (p=0,0001). There was no difference between the osteoarthritis and the arthroplasty groups for muscle activation of the VL, RF and VM muscles (p>0,05). Nevertheless, activation was different when comparing the smallest and the largest angles studied (30º and 90º, respectively) of the vastus lateralis (p=0,011) and the vastus medialis (p=0,014) muscles in both groups. These results seem to support the hypothesis that the total knee replacement produces an improvement in the quality of life by a reduction in knee joint pain and an increase in the patients mobility and a return to the daily life activities. However, this surgical procedure did not produce a functional improvement in the knee extensor muscles, as there was no increase in muscle activation nor in the expected force produced by this muscle group.

A osteoartrite de joelho caracteriza-se por um processo degenerativo da cartilagem articular e do osso subcondral, com a presença de processo inflamatório, dor, rigidez, fraqueza muscular, e que leva a uma incapacidade funcional. É uma doença degenerativa e incapacitante, e que necessita de reabilitação funcional para a melhora do indivíduo. Nos casos mais avançados, pode ser realizada a substituição da articulação degenerada por uma prótese. A cirurgia de artroplastia total de joelho pode levar o indivíduo a uma melhora funcional (redução da dor, com conseqüente melhora da capacidade de ativação do quadríceps por redução da inibição muscular reflexa, e possivelmente aumento na capacidade de produção de força do músculo) e a uma melhora da qualidade de vida. Em função disso o objetivo do presente estudo foi comparar as razões de torque e de ativação muscular dos flexores e extensores do joelho e a qualidade de vida e a dor entre indivíduos com osteoartrite de joelho (n=20) e indivíduos com artroplastia total de joelho (n=13). As razões de torque e de ativação dos músculos flexores e extensores de joelho foram avaliados durante contrações isométricas voluntárias máximas no ângulo de 60º, e contrações isocinéticas concêntricas e excêntricas nas velocidades de 60º/s e 180º/s. As razões de torque foram calculas a partir da divisão do valor do pico de torque flexor pelo extensor, e as razões de ativação da mesma forma, porém pela divisão do valor RMS do sinal EMG do músculo BF pelo valor RMS (Root Mean Square) dos músculos VL, RF e VM. As razões musculares foram comparadas entre os grupos e correlacionadas com o questionário Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Os escores do WOMAC e a dor (obtida através da escala visual analógica de dor) foram comparados entre os dois grupos. O grupo artroplastia obteve menores escores no WOMAC quando comparado ao grupo osteoartrite (p=0,022), o que indica melhora da qualidade de vida após a artroplastia total de joelho. O grupo artroplastia também apresentou menor intensidade de dor que o grupo osteoartrite (p=0,014). Tanto as razões de torque quanto as de ativação foram semelhantes entre os grupos. Uma correlação positiva foi encontrada entre as razões de torque isocinético convencional e o WOMAC para o grupo osteoartrite, nas velocidades de 60º/s (r=0,501 p=0,025) e 180º/s (r=0,863 p=0,0001). Isso demonstra que indivíduos com aumento das razões de torque, ou seja, maiores desequilíbrios musculares, apresentaram piora da qualidade de vida. Os resultados deste estudo apoiam a hipótese de que a técnica cirúrgica de artroplastia total de joelho propicia uma redução da dor e uma melhora da qualidade de vida. No entanto, não produz uma melhora na funcionalidade do sistema neuromuscular conforme demonstrou a análise das razões de torque e de ativação dos músculos flexores e extensores do joelho. / The knee osteoarthritis is characterized by a degenerative process of the joint cartilage and of the subcondral bone, with an inflammatory process, pain, joint stiffness, muscular weakness, leading to functional incapacity. It is a degenerative disease, which incapacitates the individual and needs functional rehabilitation. In the most advanced cases, the replacement of the joint is accomplished by the surgical implantation of a prosthesis. The total knee replacement surgery leads the patient to functional improvement (reduction of the pain, increasing muscle force production capacity, and possibly improvement the muscle unbalance) and an improvement of the quality of life. Therefore, the purpose of this study was to compare the muscle torque ratios and the activation ratios of the knee flexor and extensor muscles, as well as the quality of life and the pain intensity amongst patients with knee osteoarthritis (n =20) and patients with total knee replacement (n =13). The torque and activation ratios of the flexor and extensor muscles were evaluated during maximal voluntary isometric contractions at a knee joint angle of 60º, and during maximal voluntary isokinetic contractions (concentric and eccentric) at the angular velocities of 60º/s and 180º/s. The torque ratios were calculated by dividing the maximal peak torque value of the knee flexor muscles by the corresponding knee extensors torque value. The activation ratios were calculated in a similar way, by dividing the RMS values of the biceps femoris muscle by the RMS (Root Mean Square) values of the knee extensor muscles (i.e. vastus lateralis, rectus femoris and vastus medialis). All ratios (torque and activation) were compared between the two groups and correlated with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire. The activation ratios showed a similar behavior as the torque ratios for all four muscles studied, and there was no difference for these ratios between the two groups. The WOMAC scores and the pain scores (obtained by the pain visual analog scale) were compared between the two groups. The total knee replacement group obtained smaller scores in WOMAC when compared to the osteoarthritis group (p =0,022). This indicates improvement in the quality of life after the total knee replacement surgery. Patients from the total knee replacement group also presented smaller pain than the osteoarthritis group (p =0,014). A positive correlation was observed between the conventional isokinetic torque ratios and the WOMAC for the osteoarthritis group at the angular velocities of 60º/s (r=0,501 p =0,025) and 180º/s (r =0,863 p =0,0001). This indicates that patients with increased torque ratios, or in other words larger muscular unbalances, also present worsening of the quality of life. The results here presented support the idea that the total knee replacement produces a reduction in pain and an improvement in the quality of life. However, it does not improve the knee functionality as the torque and activation ratios of the knee flexor and extensor muscles was similar between the two groups.

A osteoartrite é uma desordem articular comum nos idosos, sendo responsável por causar perda da funcionalidade destes indivíduos, quando comparada a outras doenças. Sua prevalência aumenta com a idade por ser uma doença irreversível. Esta condição musculoesquelética causa dor, incapacidade física e redução da qualidade de vida. A artroplastia total de joelho é o procedimento adequado para o tratamento da osteoartrite em seus graus mais avançados, e tem apresentado uma melhora funcional dos extensores do joelho (por meio da redução da inibição reflexa e possível aumento da capacidade de produção de força) e da qualidade de vida (pela redução da dor, aumento da mobilidade e retorno às atividades de vida diárias) nesses casos avançados da doença. No entanto, os efeitos da substituição do joelho osteoartrítico pela prótese não são totalmente conhecidos. Em função disso, o objetivo do presente estudo foi comparar a ativação muscular e a produção de força (torque) de indivíduos com osteoartrite (n=20) e indivíduos com artroplastia total de joelho (n=12). O pico de torque dos músculos extensores de joelho foi avaliado durante contrações isométricas voluntárias máximas nos ângulos de 30º, 60º, 75º e 90º. Nos mesmos ângulos articulares também foi avaliada a ativação elétrica dos músculos vasto lateral, vasto medial e reto femoral, através da eletromiografia de superfície. A qualidade de vida foi comparada entre os dois grupos através do questionário WOMAC. O grupo artroplastia obteve menores escores no questionário, o que indica melhora da qualidade de vida destes indivíduos ao serem comparados com o grupo osteoartrite. O comportamento dos dados tanto para a produção de torque como para a ativação muscular, apresentou-se semelhante nos dois grupos. A produção de torque não apresentou diferença significativa entre os grupos avaliados (p=0,775), sendo que a única diferença observada foi para o torque entre os ângulos testados (p=0,0001). Assim como para a produção de torque, a ativação muscular não apresentou diferença significativa entre os grupos osteoartrite e artroplastia total de joelho para os músculos VL, RF e VM (p>0,05). Somente para o menor ângulo (30º) e para o maior ângulo (90º) houve diferença significativa da ativação muscular em relação aos ângulos para os músculos vasto lateral (p=0,011) e vasto medial (p=0,014). Os resultados apresentados neste estudo suportam a hipótese de que a técnica cirúrgica de artroplastia total de joelho propicia uma redução da dor e uma melhora da qualidade de vida. No entanto, essa melhora na qualidade de vida parece não ser refletida em uma melhora funcional após a colocação da prótese, uma vez que não foi observado um aumento na ativação muscular com um correspondente aumento na capacidade de produção de força dos músculos extensores do joelho. / Osteoarthritis is a degenerative disease prevalent in the elderly population characterized by pain, disability and decrease of quality of life. Total knee replacement is indicated for the last stages of the disease, and shows a functional improvement of the knee extensor muscles (by a reduction of reflex inhibition and possibly by increasing muscle force production capacity) and improvement of quality of life (by the reduction in pain, increase in mobility and return to daily life activities) in these advanced stages of the disease. However, the functional effects of the joint replacement are not completely understood. Therefore, the purpose of this study was to compare both the muscle activation and the force production (torque) developed by patients with osteoarthritis (n=20) and patients which underwent total knee replacement (n=12). The knee extensor muscles peak torque was evaluated during maximal voluntary isometric contractions at the joint angles of 30º, 60º, 75º and 90º of knee extension. At the same joint angles the electrical activation was obtained, by surface electromyography from the vastus lateralis, the vastus medialis and the rectus femoris muscles. The WOMAC questionnaire was used to compare the quality of life between the two groups of the study. The arthroplasty group showed lower scores, indicating an improvement in the quality of life compare to the osteoarthritis group. Both groups showed a similar behavior in the torque production and in the muscle activation. Torque production was similar between the two groups (p=0,775), although there was a difference in the torque amongst the studied angles (p=0,0001). There was no difference between the osteoarthritis and the arthroplasty groups for muscle activation of the VL, RF and VM muscles (p>0,05). Nevertheless, activation was different when comparing the smallest and the largest angles studied (30º and 90º, respectively) of the vastus lateralis (p=0,011) and the vastus medialis (p=0,014) muscles in both groups. These results seem to support the hypothesis that the total knee replacement produces an improvement in the quality of life by a reduction in knee joint pain and an increase in the patients mobility and a return to the daily life activities. However, this surgical procedure did not produce a functional improvement in the knee extensor muscles, as there was no increase in muscle activation nor in the expected force produced by this muscle group.

A osteoartrite de joelho caracteriza-se por um processo degenerativo da cartilagem articular e do osso subcondral, com a presença de processo inflamatório, dor, rigidez, fraqueza muscular, e que leva a uma incapacidade funcional. É uma doença degenerativa e incapacitante, e que necessita de reabilitação funcional para a melhora do indivíduo. Nos casos mais avançados, pode ser realizada a substituição da articulação degenerada por uma prótese. A cirurgia de artroplastia total de joelho pode levar o indivíduo a uma melhora funcional (redução da dor, com conseqüente melhora da capacidade de ativação do quadríceps por redução da inibição muscular reflexa, e possivelmente aumento na capacidade de produção de força do músculo) e a uma melhora da qualidade de vida. Em função disso o objetivo do presente estudo foi comparar as razões de torque e de ativação muscular dos flexores e extensores do joelho e a qualidade de vida e a dor entre indivíduos com osteoartrite de joelho (n=20) e indivíduos com artroplastia total de joelho (n=13). As razões de torque e de ativação dos músculos flexores e extensores de joelho foram avaliados durante contrações isométricas voluntárias máximas no ângulo de 60º, e contrações isocinéticas concêntricas e excêntricas nas velocidades de 60º/s e 180º/s. As razões de torque foram calculas a partir da divisão do valor do pico de torque flexor pelo extensor, e as razões de ativação da mesma forma, porém pela divisão do valor RMS do sinal EMG do músculo BF pelo valor RMS (Root Mean Square) dos músculos VL, RF e VM. As razões musculares foram comparadas entre os grupos e correlacionadas com o questionário Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Os escores do WOMAC e a dor (obtida através da escala visual analógica de dor) foram comparados entre os dois grupos. O grupo artroplastia obteve menores escores no WOMAC quando comparado ao grupo osteoartrite (p=0,022), o que indica melhora da qualidade de vida após a artroplastia total de joelho. O grupo artroplastia também apresentou menor intensidade de dor que o grupo osteoartrite (p=0,014). Tanto as razões de torque quanto as de ativação foram semelhantes entre os grupos. Uma correlação positiva foi encontrada entre as razões de torque isocinético convencional e o WOMAC para o grupo osteoartrite, nas velocidades de 60º/s (r=0,501 p=0,025) e 180º/s (r=0,863 p=0,0001). Isso demonstra que indivíduos com aumento das razões de torque, ou seja, maiores desequilíbrios musculares, apresentaram piora da qualidade de vida. Os resultados deste estudo apoiam a hipótese de que a técnica cirúrgica de artroplastia total de joelho propicia uma redução da dor e uma melhora da qualidade de vida. No entanto, não produz uma melhora na funcionalidade do sistema neuromuscular conforme demonstrou a análise das razões de torque e de ativação dos músculos flexores e extensores do joelho. / The knee osteoarthritis is characterized by a degenerative process of the joint cartilage and of the subcondral bone, with an inflammatory process, pain, joint stiffness, muscular weakness, leading to functional incapacity. It is a degenerative disease, which incapacitates the individual and needs functional rehabilitation. In the most advanced cases, the replacement of the joint is accomplished by the surgical implantation of a prosthesis. The total knee replacement surgery leads the patient to functional improvement (reduction of the pain, increasing muscle force production capacity, and possibly improvement the muscle unbalance) and an improvement of the quality of life. Therefore, the purpose of this study was to compare the muscle torque ratios and the activation ratios of the knee flexor and extensor muscles, as well as the quality of life and the pain intensity amongst patients with knee osteoarthritis (n =20) and patients with total knee replacement (n =13). The torque and activation ratios of the flexor and extensor muscles were evaluated during maximal voluntary isometric contractions at a knee joint angle of 60º, and during maximal voluntary isokinetic contractions (concentric and eccentric) at the angular velocities of 60º/s and 180º/s. The torque ratios were calculated by dividing the maximal peak torque value of the knee flexor muscles by the corresponding knee extensors torque value. The activation ratios were calculated in a similar way, by dividing the RMS values of the biceps femoris muscle by the RMS (Root Mean Square) values of the knee extensor muscles (i.e. vastus lateralis, rectus femoris and vastus medialis). All ratios (torque and activation) were compared between the two groups and correlated with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire. The activation ratios showed a similar behavior as the torque ratios for all four muscles studied, and there was no difference for these ratios between the two groups. The WOMAC scores and the pain scores (obtained by the pain visual analog scale) were compared between the two groups. The total knee replacement group obtained smaller scores in WOMAC when compared to the osteoarthritis group (p =0,022). This indicates improvement in the quality of life after the total knee replacement surgery. Patients from the total knee replacement group also presented smaller pain than the osteoarthritis group (p =0,014). A positive correlation was observed between the conventional isokinetic torque ratios and the WOMAC for the osteoarthritis group at the angular velocities of 60º/s (r=0,501 p =0,025) and 180º/s (r =0,863 p =0,0001). This indicates that patients with increased torque ratios, or in other words larger muscular unbalances, also present worsening of the quality of life. The results here presented support the idea that the total knee replacement produces a reduction in pain and an improvement in the quality of life. However, it does not improve the knee functionality as the torque and activation ratios of the knee flexor and extensor muscles was similar between the two groups.

A osteoartrite é uma desordem articular comum nos idosos, sendo responsável por causar perda da funcionalidade destes indivíduos, quando comparada a outras doenças. Sua prevalência aumenta com a idade por ser uma doença irreversível. Esta condição musculoesquelética causa dor, incapacidade física e redução da qualidade de vida. A artroplastia total de joelho é o procedimento adequado para o tratamento da osteoartrite em seus graus mais avançados, e tem apresentado uma melhora funcional dos extensores do joelho (por meio da redução da inibição reflexa e possível aumento da capacidade de produção de força) e da qualidade de vida (pela redução da dor, aumento da mobilidade e retorno às atividades de vida diárias) nesses casos avançados da doença. No entanto, os efeitos da substituição do joelho osteoartrítico pela prótese não são totalmente conhecidos. Em função disso, o objetivo do presente estudo foi comparar a ativação muscular e a produção de força (torque) de indivíduos com osteoartrite (n=20) e indivíduos com artroplastia total de joelho (n=12). O pico de torque dos músculos extensores de joelho foi avaliado durante contrações isométricas voluntárias máximas nos ângulos de 30º, 60º, 75º e 90º. Nos mesmos ângulos articulares também foi avaliada a ativação elétrica dos músculos vasto lateral, vasto medial e reto femoral, através da eletromiografia de superfície. A qualidade de vida foi comparada entre os dois grupos através do questionário WOMAC. O grupo artroplastia obteve menores escores no questionário, o que indica melhora da qualidade de vida destes indivíduos ao serem comparados com o grupo osteoartrite. O comportamento dos dados tanto para a produção de torque como para a ativação muscular, apresentou-se semelhante nos dois grupos. A produção de torque não apresentou diferença significativa entre os grupos avaliados (p=0,775), sendo que a única diferença observada foi para o torque entre os ângulos testados (p=0,0001). Assim como para a produção de torque, a ativação muscular não apresentou diferença significativa entre os grupos osteoartrite e artroplastia total de joelho para os músculos VL, RF e VM (p>0,05). Somente para o menor ângulo (30º) e para o maior ângulo (90º) houve diferença significativa da ativação muscular em relação aos ângulos para os músculos vasto lateral (p=0,011) e vasto medial (p=0,014). Os resultados apresentados neste estudo suportam a hipótese de que a técnica cirúrgica de artroplastia total de joelho propicia uma redução da dor e uma melhora da qualidade de vida. No entanto, essa melhora na qualidade de vida parece não ser refletida em uma melhora funcional após a colocação da prótese, uma vez que não foi observado um aumento na ativação muscular com um correspondente aumento na capacidade de produção de força dos músculos extensores do joelho. / Osteoarthritis is a degenerative disease prevalent in the elderly population characterized by pain, disability and decrease of quality of life. Total knee replacement is indicated for the last stages of the disease, and shows a functional improvement of the knee extensor muscles (by a reduction of reflex inhibition and possibly by increasing muscle force production capacity) and improvement of quality of life (by the reduction in pain, increase in mobility and return to daily life activities) in these advanced stages of the disease. However, the functional effects of the joint replacement are not completely understood. Therefore, the purpose of this study was to compare both the muscle activation and the force production (torque) developed by patients with osteoarthritis (n=20) and patients which underwent total knee replacement (n=12). The knee extensor muscles peak torque was evaluated during maximal voluntary isometric contractions at the joint angles of 30º, 60º, 75º and 90º of knee extension. At the same joint angles the electrical activation was obtained, by surface electromyography from the vastus lateralis, the vastus medialis and the rectus femoris muscles. The WOMAC questionnaire was used to compare the quality of life between the two groups of the study. The arthroplasty group showed lower scores, indicating an improvement in the quality of life compare to the osteoarthritis group. Both groups showed a similar behavior in the torque production and in the muscle activation. Torque production was similar between the two groups (p=0,775), although there was a difference in the torque amongst the studied angles (p=0,0001). There was no difference between the osteoarthritis and the arthroplasty groups for muscle activation of the VL, RF and VM muscles (p>0,05). Nevertheless, activation was different when comparing the smallest and the largest angles studied (30º and 90º, respectively) of the vastus lateralis (p=0,011) and the vastus medialis (p=0,014) muscles in both groups. These results seem to support the hypothesis that the total knee replacement produces an improvement in the quality of life by a reduction in knee joint pain and an increase in the patients mobility and a return to the daily life activities. However, this surgical procedure did not produce a functional improvement in the knee extensor muscles, as there was no increase in muscle activation nor in the expected force produced by this muscle group.