The Vastus Medialis Insertion Is More Proximal and Medial in Patients With Patellar Instability: A Magnetic Resonance Imaging Case-Control Study.

BACKGROUND: The anatomy and function of the quadriceps muscle play a role in patellofemoral stability. Few studies have evaluated anatomic differences in the vastus medialis between patients with and without patellar instability. PURPOSE: To compare the anatomy of the vastus medialis using magnetic resonance imaging in patients with patellar instability to a control group. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: A group of patients with patellar instability were sex-matched with a control group with anterior cruciate ligament tears, meniscal injuries, or sprains; patients younger than 15 years were excluded. The anatomy of the vastus medialis was examined by the distance between the distal origin of the vastus medialis in the femur and the medial femoral condyle, the distance from the proximal pole of the patella to the most distal insertion of the muscle and its ratio to the length of the articular surface of the patella, and a qualitative description of the insertion position of the muscle fibers (directly in the patella or the medial retinaculum). RESULTS: Both groups comprised 78 knees (48 female; 61.5%). The mean age in the control and patellar instability groups was 30.2 ± 7.8 years and 25.6 ± 7.5 years, respectively (P = .001). The distance from the vastus origin to the condyle was 27.52 ± 3.49 mm and 26.59 ± 3.43 mm, respectively (P = .041); the distance from the proximal pole of the patella to the most distal muscle insertion was 17.59 ± 5.54 mm and 15.02 ± 4.18 mm, respectively (P < .001); and the ratio of this distance to the joint surface was 0.586 ± 0.180 and 0.481 ± 0.130, respectively (P < .001). In 75.6% of knees in the patellar instability group, the insertion of the vastus was into the medial retinaculum and not into the patella compared with 52.6% in the control group (P = .003; odds ratio, 2.8). CONCLUSION: The distal insertion of the vastus medialis differed in knees with patellar instability, with a more proximal insertion and less patellar coverage relative to controls, and was more frequently found in the retinaculum instead of directly in the patella.

Septic arthritis of the knee: clinical and laboratory comparison of groups with different etiologies

OBJECTIVES: To clinically and epidemiologically characterize a population diagnosed with and treated for septic arthritis of the knee, to evaluate the treatment results and to analyze the differences between patients with positive and negative culture results, patients with Gram-positive and Gram-negative bacterial isolates and patients with S. aureus- and non-S. aureus-related infections. METHODS: One hundred and five patients with septic knee arthritis were included in this study. The clinical and epidemiological data were evaluated. Statistical analysis was performed to compare patients with and without an isolated causative agent, patients with Gram-positive and Gram-negative pathogens and patients with S. aureus-related and non S. aureus-related infections. RESULTS: Causative agents were isolated in 81 patients. Gram-positive bacteria were isolated in 65 patients and Gram-negative bacteria were isolated in 16 patients. The most commonly isolated bacterium was S. aureus. Comparing cases with an isolated pathogen to cases without an isolated pathogen, no differences between the studied variables were found except for the longer hospital stays of patients in whom an etiological agent was identified. When comparing Gram-positive bacteria with Gram-negative bacteria, patients with Gram-positive-related infections exhibited higher leukocyte counts. Patients with S. aureus-related infections were more frequently associated with healthcare-related environmental encounters. CONCLUSION: S. aureus is the most common pathogen of septic knee arthritis. Major differences were not observed between infections with isolated and non-isolated pathogens and between infections with Gram-positive and Gram-negative bacteria. S. aureus infections were more likely to be associated with a prior healthcare environment exposure.

Index of fatigue quadriceps in soccer athletes after anterior cruciate ligament reconstruction.

OBJECTIVE: The present study aimed to evaluate the muscle fatigue of the quadriceps muscle in high-performance soccer players undergoing (anterior cruciate ligament) ACL reconstruction. METHODS: We evaluated 17 high-performance soccer players from three professional soccer teams of a state in Brazil from August 2011 to July 2012. All subjects were evaluated between 5.5 and 7 months after ACL reconstruction with a Biodex® isokinetic dynamometer (System 4 Pro) with test protocol CON/CON at 60°/s and 300°/s with 5 and 15 repetitions, respectively. In the calculation of local muscle fatigue, the fatigue index was used, which is calculated by dividing the labor done in the first one-third of the repetitions by that done at the final one-third of the repetitions, and multiplying by 100 to express a unit in percentage (i.e., as a discrete quantitative variable). RESULTS: All subjects were male, with a mean age of 21.3 ± 4.4 years and mean BMI 23.4 ± 1.53 cm; left dominance was observed in 47% (n = 8) of athletes, and right dominance, in 53% (n = 9) of athletes; and the limb involved in the lesion was the dominant in 29% (n = 5) and the non-dominant in 71% (n = 12). Fatigue rates were 19.6% in the involved limb and 29.0% in the non-involved limb. CONCLUSION: The results allow us to conclude that there was no significant difference between the limbs involved and not in ACL injuries regarding local muscle fatigue. No association was observed between the dominant side and the limb involved in the ACL injury.

OBJETIVOS: O presente estudo propõe avaliar a fadiga muscular do músculo quadríceps em atletas de futebol de alto rendimento submetidos à ligamentoplastia do ligamento cruzado anterior (LCA). MÉTODOS: Foram avaliados 17 atletas de futebol com alto rendimento que pertenciam conjuntamente a três times de futebol profissional de um determinado estado brasileiro, de agosto de 2011 a julho de 2012. Todos foram avaliados entre 5,5 e 7 meses de pós-operatório de ligamentoplastia do LCA no dinamômetro isocinético da marca Biodex® (System 4 Pro) com protocolo de teste CON/CON nas velocidades de 60°/s e 300°/s com 5 e 15 repetições, respectivamente. No cálculo da fadiga muscular local, usamos o índice de fadiga que é calculado com a divisão do trabalho feito no terço inicial das repetições pelo terço final das repetições e a multiplicação por 100 para expressar uma unidade em porcentagem (i.e., variável quantitativa discreta). RESULTADOS: Todos eram do sexo masculino, com média de 21,3 ± 4,4 anos; IMC médio de 23,4 ± 1,53 cm; com dominância à esquerda em 47% (n = 8) dos atletas; e a direita em 53% (n = 9) dos atletas; o membro envolvido na lesão foi o dominante em 29% (n = 5) dos casos e o não dominante em 71% (n = 12). Os índices de fadiga foram de 19,6% no membro envolvido e de 29,0% nos membros não envolvidos. CONCLUSÃO: Os resultados nos permitem concluir que não há diferença significativa entre os membros envolvidos e não envolvidos na lesão de LCA no que diz respeito à fadiga muscular local. Também não foi observada associação entre ser destro ou canhoto com o membro envolvido na lesão de LCA.

Index of fatigue quadriceps in soccer athletes after anterior cruciate ligament reconstruction / Índice de fadiga do músculo quadríceps femoral em atletas de futebol após reconstrução do ligamento cruzado anterior

ABSTRACT OBJECTIVE: The present study aimed to evaluate the muscle fatigue of the quadriceps muscle in high-performance soccer players undergoing (anterior cruciate ligament) ACL reconstruction. METHODS: We evaluated 17 high-performance soccer players from three professional soccer teams of a state in Brazil from August 2011 to July 2012. All subjects were evaluated between 5.5 and 7 months after ACL reconstruction with a Biodex(r) isokinetic dynamometer (System 4 Pro) with test protocol CON/CON at 60°/s and 300°/s with 5 and 15 repetitions, respectively. In the calculation of local muscle fatigue, the fatigue index was used, which is calculated by dividing the labor done in the first one-third of the repetitions by that done at the final one-third of the repetitions, and multiplying by 100 to express a unit in percentage (i.e., as a discrete quantitative variable). RESULTS: All subjects were male, with a mean age of 21.3 ± 4.4 years and mean BMI 23.4 ± 1.53 cm; left dominance was observed in 47% (n = 8) of athletes, and right dominance, in 53% (n = 9) of athletes; and the limb involved in the lesion was the dominant in 29% (n = 5) and the non-dominant in 71% (n = 12). Fatigue rates were 19.6% in the involved limb and 29.0% in the non-involved limb. CONCLUSION: The results allow us to conclude that there was no significant difference between the limbs involved and not in ACL injuries regarding local muscle fatigue. No association was observed between the dominant side and the limb involved in the ACL injury.

RESUMO OBJETIVOS: O presente estudo propõe avaliar a fadiga muscular do músculo quadríceps em atletas de futebol de alto rendimento submetidos à ligamentoplastia do ligamento cruzado anterior (LCA). MÉTODOS: Foram avaliados 17 atletas de futebol com alto rendimento que pertenciam conjuntamente a três times de futebol profissional de um determinado estado brasileiro, de agosto de 2011 a julho de 2012. Todos foram avaliados entre 5,5 e 7 meses de pós-operatório de ligamentoplastia do LCA no dinamômetro isocinético da marca Biodex(r) (System 4 Pro) com protocolo de teste CON/CON nas velocidades de 60°/s e 300°/s com 5 e 15 repetições, respectivamente. No cálculo da fadiga muscular local, usamos o índice de fadiga que é calculado com a divisão do trabalho feito no terço inicial das repetições pelo terço final das repetições e a multiplicação por 100 para expressar uma unidade em porcentagem (i.e., variável quantitativa discreta). RESULTADOS: Todos eram do sexo masculino, com média de 21,3 ± 4,4 anos; IMC médio de 23,4 ± 1,53 cm; com dominância à esquerda em 47% (n = 8) dos atletas; e a direita em 53% (n = 9) dos atletas; o membro envolvido na lesão foi o dominante em 29% (n = 5) dos casos e o não dominante em 71% (n = 12). Os índices de fadiga foram de 19,6% no membro envolvido e de 29,0% nos membros não envolvidos. CONCLUSÃO: Os resultados nos permitem concluir que não há diferença significativa entre os membros envolvidos e não envolvidos na lesão de LCA no que diz respeito à fadiga muscular local. Também não foi observada associação entre ser destro ou canhoto com o membro envolvido na lesão de LCA.

Septic arthritis of the knee: clinical and laboratory comparison of groups with different etiologies.

OBJECTIVES:: To clinically and epidemiologically characterize a population diagnosed with and treated for septic arthritis of the knee, to evaluate the treatment results and to analyze the differences between patients with positive and negative culture results, patients with Gram-positive and Gram-negative bacterial isolates and patients with S. aureus- and non-S. aureus-related infections. METHODS:: One hundred and five patients with septic knee arthritis were included in this study. The clinical and epidemiological data were evaluated. Statistical analysis was performed to compare patients with and without an isolated causative agent, patients with Gram-positive and Gram-negative pathogens and patients with S. aureus-related and non S. aureus-related infections. RESULTS:: Causative agents were isolated in 81 patients. Gram-positive bacteria were isolated in 65 patients and Gram-negative bacteria were isolated in 16 patients. The most commonly isolated bacterium was S. aureus. Comparing cases with an isolated pathogen to cases without an isolated pathogen, no differences between the studied variables were found except for the longer hospital stays of patients in whom an etiological agent was identified. When comparing Gram-positive bacteria with Gram-negative bacteria, patients with Gram-positive-related infections exhibited higher leukocyte counts. Patients with S. aureus-related infections were more frequently associated with healthcare-related environmental encounters. CONCLUSION:: S. aureus is the most common pathogen of septic knee arthritis. Major differences were not observed between infections with isolated and non-isolated pathogens and between infections with Gram-positive and Gram-negative bacteria. S. aureus infections were more likely to be associated with a prior healthcare environment exposure.