Varus knee thrust is an abnormal frontal-plane movement (i.e., an out-bowing) of the knee that occurs during the weight-acceptance phase of gait. Varus thrust is of clinical interest, as it is a potentially-modifiable biomechanical risk factor for knee osteoarthritis (OA) progression and has been associated with knee pain. The overall aim of this dissertation is to identify the structural and symptomatic consequences of varus thrust at the knee and along the lower limb, and the possible anatomical and sensorimotor causes of varus thrust in older adults with or at risk for OA. Varus thrust was assessed in Multicenter Osteoarthritis (MOST) Study participants using high-speed videos of self-paced walking. Varus thrust was observed in 31.3% of 3730 knees. We investigated the longitudinal relation of varus thrust to MRI lesions and found that thrust was associated with increased odds of incident and worsening bone marrow lesions and worsening cartilage loss. We then investigated the longitudinal association of varus thrust with WOMAC knee pain and found that thrust was associated with increased odds of incident and worsening total WOMAC knee pain and worsening pain during weight-bearing and non-weight bearing activities. In an ancillary quantitative gait analysis of a single subject with unilateral varus thrust, we found altered joint moments at the hip, knee, and ankle in the thrust limb compared to the non-thrust limb. We bolstered this pilot data with an investigation of low back and lower extremity pain in the presence of thrust in MOST participants: limbs with thrust had increased odds of incident frequent pain proximal (hip or low back) and distal (ankle and foot) to the knee compared to limbs without thrust. Finally, we investigated the cross-sectional relation of anatomical and sensorimotor impairments at the knee and lower extremity to the prevalence of varus thrust. Thrust was most prevalent in limbs with static varus malalignment and supinated feet during gait, while increasing static knee laxity had a protective effect against thrust. These results fill substantial gaps in the narrative regarding the role of varus thrust in OA development.

Inaug.-diss.--Hamburg. / Cover title. "Literaturangaben": p. 62.

Inaug.-diss.--Hamburg. / Cover title. "Literaturangaben": p. 62.

BACKGROUND: Up to 37% of people with knee osteoarthritis (OA) present with varus thrust, an abrupt and dynamic worsening of varus alignment during the load-bearing stages of gait. Varus thrust is associated with up to 4-fold increased odds of medial knee OA progression as well as worsening clinical outcomes. While the implications of varus thrust have been well studied, the neuromuscular factors related to varus thrust are still not well understood and many studies report contradictory findings. Additionally, many potential factors remain unstudied. This warrants further efforts to determine associations between neuromuscular factors and varus thrust. The purpose of this study is to investigate knee muscle strength and muscle activation during walking in relation to biomechanical measures of varus thrust. METHODS: Analyses of existing data from participants with and without knee OA recruited at three institutions were used for this study. All participants underwent gait analyses at their self-selected pace while kinematics, kinetics, and surface EMG data were collected. Quadriceps and hamstrings strength was measured using isokinetic dynamometry. Gait data were used to calculate adduction excursion and peak knee adduction velocity as measures of varus thrust. A custom MATLAB code was used to calculate the rate of force development of the quadriceps, and a muscular co-contraction equation was used to calculate co-contraction values for four antagonist muscle pairs (VL-LH, VM-MH, VL-LG, and VM-MG) from surface EMG data during walking. Correlational analyses were performed to assess associations of strength, rate of force development, and muscle co-contraction variables with measures of varus thrust. RESULTS: A total of 183 participants were enrolled, however, a varying number of participants were used for different analyses based on available data. Peak isokinetic quadriceps strength at 60 degrees/second and peak hamstrings strength at both 60 and 120 degrees/second were negatively correlated with knee adduction velocity in people with knee OA. This association was not observed for people without knee OA. VLLH and VMMH co-contraction indices during preactivation were positively correlated with knee adduction excursion. VLLG co-contraction during midstance was positively correlated with peak knee adduction velocity. Association between rate of force development and varus thrust variables was not significant. CONCLUSIONS: Lower isokinetic thigh muscle strength and greater preactivation during walking are related to greater magnitude of varus thrust measured using motion capture. These results advance our understanding of neuromuscular factors related to varus thrust and could inform future interventions to reduce thrust and prevent further progression of OA. / 2020-06-14T00:00:00Z

Background: Cubitus varus is a cosmetically unacceptable complication of supracondylar fractures of the elbow in children. We have performed the lateral closing wedge (French) osteotomy to correct the varus for 27 years. More complex osteotomies have been described to correct the associated hyperextension and internal rotation deformities and to prevent a prominent lateral condyle. Methods: We retrospectively reviewed 90 consecutive patients (1986-2012). The mean age of the patients at surgery was 8.2 years (3 to14 years). The varus angle (mean 21.4°, range 8°- 40°) was assessed pre-operatively with the humero-elbow-wrist (HEW) angle. The postoperative carrying angle (mean 10.4) and the pre- and postoperative range of movement were assessed clinically. The lateral condylar prominence index (LCPI) was retrospectively measured at union. Results: Seventy five (93.3%) of the patients had a good or excellent result. Six (6.7%) had a poor result (residual varus, loss of >20°of pre-operative range of flexion or extension or a complication necessitating repeat surgery). There were no neuro-vascular complications. The mean LCPI was +0.14. Conclusions: The results of the French osteotomy are comparable to the more technically demanding dome, step-cut translation and multi-planar osteotomies, with a lower complication rate. The literature reports adequate remodelling of the hyperextension deformity ( ≤ 10 years) patient. Level of evidence: Level IV: Case series

Objetivo:Verificar a prevalência da restrição da amplitude de movimento (ADM) rotacional do quadril em jovens atletas e não atletas de futebol, e sua potencial correlação com o alinhamento dos joelhos no plano frontal. Delineamento da Pesquisa: Estudo transversal Amostra: Amostra por conveniência com 425 meninos de 9 a 18 anos, divididos em Grupo Atleta (jogadores de futebol das categorias de base de nível competitivo) com idade média de 13,3 anos (± 2,7); e Grupo Não Atleta (alunos do ensino fundamental e médio) com idade de 14,4 anos (± 2,5). Resultados: No Grupo Atleta, a média de rotação interna (RI) do quadril foi de 20,7º(±5,8º), e de rotação externa (RE) 36,5º (±7,4º), e no Não Atleta, 32,8º (±2,9º), e 46,7º(±4,8º), respectivamente. No Grupo Atleta, houve diminuição da RI e RE ao longo dos anos de prática desportiva, especialmente na RI (p<0,001). No Grupo Não Atleta, houve uma diminuição significativa somente na RE (p<0,001). No Grupo Atleta houve grande prevalência de varo em todas as faixas etárias (p=0,153), e no Grupo Não Atleta, a proporção de varo aumentou com o avanço da idade (p=0,001). Houve correlação entre RI e alinhamento dos joelhos, com a RI tendendo a diminuir com maior grau de varo (rs=0,19; p=0,009), e seu estabelecimento precedeu a restrição articular. Conclusão: Os dados da pesquisa apontam para uma maior prevalência de restrição rotacional do quadril, especialmente da RI, em jovens jogadores de futebol, assim como uma prevalência de alinhamento em varo dos joelhos nestes indivíduos. O varo dos joelhos se correlacionou com a RI do quadril. / Objective: To investigate the prevalence of decreased hip rotation range of motion (ROM) among young soccer players and non-athletes and its potential correlation with knee alignment. Design: cross-sectional study. Participants: 425 young men, divided into an Athlete group (competitive soccer players, mean age 13.3±2.7 years) and a Non-Athlete group (primary and secondary school students, mean age 14.4±2.5 years). Interventions: Measurements of hip rotation range of motion and frontal plane knee alignment (varus/valgus alignment). Results: In the Athlete group, mean hip internal rotation (IR) ROM was 20.7±5.8º, versus 32.8±2.9º in the Non-Athlete group, and external rotation (ER) ROM was 36.5±7.4º, versus 46.7±4.8º in the Non-Athlete group. In the Athlete group, IR and ER (particularly the former) gradually decreased with advancing years of sport practice (p<0.001). In the Non-Athlete group, this decrease was greater in ER (p<0.001). Varus alignment was highly prevalent across all ages in the Athlete group (p=0.153), and in the Non-Athlete group, the proportion of subjects with genu varum increased with advancing age (p=0.001). A correlation was found between IR and knee alignment, with rotation tending to be more limited at greater degrees of varus (rs=0.19; p=0.009). Conclusion: The findings of this study suggest that a gradual decrease in hip rotation ROM, particularly in internal rotation, occurs among young soccer players, and that varus alignment of the knee is highly prevalent in this population. Decreased hip IR was associated with varus alignment in athlete group, and it seemed to arise before this upper joint restriction.

Objetivo:Verificar a prevalência da restrição da amplitude de movimento (ADM) rotacional do quadril em jovens atletas e não atletas de futebol, e sua potencial correlação com o alinhamento dos joelhos no plano frontal. Delineamento da Pesquisa: Estudo transversal Amostra: Amostra por conveniência com 425 meninos de 9 a 18 anos, divididos em Grupo Atleta (jogadores de futebol das categorias de base de nível competitivo) com idade média de 13,3 anos (± 2,7); e Grupo Não Atleta (alunos do ensino fundamental e médio) com idade de 14,4 anos (± 2,5). Resultados: No Grupo Atleta, a média de rotação interna (RI) do quadril foi de 20,7º(±5,8º), e de rotação externa (RE) 36,5º (±7,4º), e no Não Atleta, 32,8º (±2,9º), e 46,7º(±4,8º), respectivamente. No Grupo Atleta, houve diminuição da RI e RE ao longo dos anos de prática desportiva, especialmente na RI (p<0,001). No Grupo Não Atleta, houve uma diminuição significativa somente na RE (p<0,001). No Grupo Atleta houve grande prevalência de varo em todas as faixas etárias (p=0,153), e no Grupo Não Atleta, a proporção de varo aumentou com o avanço da idade (p=0,001). Houve correlação entre RI e alinhamento dos joelhos, com a RI tendendo a diminuir com maior grau de varo (rs=0,19; p=0,009), e seu estabelecimento precedeu a restrição articular. Conclusão: Os dados da pesquisa apontam para uma maior prevalência de restrição rotacional do quadril, especialmente da RI, em jovens jogadores de futebol, assim como uma prevalência de alinhamento em varo dos joelhos nestes indivíduos. O varo dos joelhos se correlacionou com a RI do quadril. / Objective: To investigate the prevalence of decreased hip rotation range of motion (ROM) among young soccer players and non-athletes and its potential correlation with knee alignment. Design: cross-sectional study. Participants: 425 young men, divided into an Athlete group (competitive soccer players, mean age 13.3±2.7 years) and a Non-Athlete group (primary and secondary school students, mean age 14.4±2.5 years). Interventions: Measurements of hip rotation range of motion and frontal plane knee alignment (varus/valgus alignment). Results: In the Athlete group, mean hip internal rotation (IR) ROM was 20.7±5.8º, versus 32.8±2.9º in the Non-Athlete group, and external rotation (ER) ROM was 36.5±7.4º, versus 46.7±4.8º in the Non-Athlete group. In the Athlete group, IR and ER (particularly the former) gradually decreased with advancing years of sport practice (p<0.001). In the Non-Athlete group, this decrease was greater in ER (p<0.001). Varus alignment was highly prevalent across all ages in the Athlete group (p=0.153), and in the Non-Athlete group, the proportion of subjects with genu varum increased with advancing age (p=0.001). A correlation was found between IR and knee alignment, with rotation tending to be more limited at greater degrees of varus (rs=0.19; p=0.009). Conclusion: The findings of this study suggest that a gradual decrease in hip rotation ROM, particularly in internal rotation, occurs among young soccer players, and that varus alignment of the knee is highly prevalent in this population. Decreased hip IR was associated with varus alignment in athlete group, and it seemed to arise before this upper joint restriction.

Objetivo:Verificar a prevalência da restrição da amplitude de movimento (ADM) rotacional do quadril em jovens atletas e não atletas de futebol, e sua potencial correlação com o alinhamento dos joelhos no plano frontal. Delineamento da Pesquisa: Estudo transversal Amostra: Amostra por conveniência com 425 meninos de 9 a 18 anos, divididos em Grupo Atleta (jogadores de futebol das categorias de base de nível competitivo) com idade média de 13,3 anos (± 2,7); e Grupo Não Atleta (alunos do ensino fundamental e médio) com idade de 14,4 anos (± 2,5). Resultados: No Grupo Atleta, a média de rotação interna (RI) do quadril foi de 20,7º(±5,8º), e de rotação externa (RE) 36,5º (±7,4º), e no Não Atleta, 32,8º (±2,9º), e 46,7º(±4,8º), respectivamente. No Grupo Atleta, houve diminuição da RI e RE ao longo dos anos de prática desportiva, especialmente na RI (p<0,001). No Grupo Não Atleta, houve uma diminuição significativa somente na RE (p<0,001). No Grupo Atleta houve grande prevalência de varo em todas as faixas etárias (p=0,153), e no Grupo Não Atleta, a proporção de varo aumentou com o avanço da idade (p=0,001). Houve correlação entre RI e alinhamento dos joelhos, com a RI tendendo a diminuir com maior grau de varo (rs=0,19; p=0,009), e seu estabelecimento precedeu a restrição articular. Conclusão: Os dados da pesquisa apontam para uma maior prevalência de restrição rotacional do quadril, especialmente da RI, em jovens jogadores de futebol, assim como uma prevalência de alinhamento em varo dos joelhos nestes indivíduos. O varo dos joelhos se correlacionou com a RI do quadril. / Objective: To investigate the prevalence of decreased hip rotation range of motion (ROM) among young soccer players and non-athletes and its potential correlation with knee alignment. Design: cross-sectional study. Participants: 425 young men, divided into an Athlete group (competitive soccer players, mean age 13.3±2.7 years) and a Non-Athlete group (primary and secondary school students, mean age 14.4±2.5 years). Interventions: Measurements of hip rotation range of motion and frontal plane knee alignment (varus/valgus alignment). Results: In the Athlete group, mean hip internal rotation (IR) ROM was 20.7±5.8º, versus 32.8±2.9º in the Non-Athlete group, and external rotation (ER) ROM was 36.5±7.4º, versus 46.7±4.8º in the Non-Athlete group. In the Athlete group, IR and ER (particularly the former) gradually decreased with advancing years of sport practice (p<0.001). In the Non-Athlete group, this decrease was greater in ER (p<0.001). Varus alignment was highly prevalent across all ages in the Athlete group (p=0.153), and in the Non-Athlete group, the proportion of subjects with genu varum increased with advancing age (p=0.001). A correlation was found between IR and knee alignment, with rotation tending to be more limited at greater degrees of varus (rs=0.19; p=0.009). Conclusion: The findings of this study suggest that a gradual decrease in hip rotation ROM, particularly in internal rotation, occurs among young soccer players, and that varus alignment of the knee is highly prevalent in this population. Decreased hip IR was associated with varus alignment in athlete group, and it seemed to arise before this upper joint restriction.

O presente estudo compara uma nova técnica de osteotomia varizante em cúpula à tradicional osteotomia intertrocantérica varizante do fêmur em cadáveres de cães. Foram utilizados 10 pares de fêmures, provenientes de cães eutanasiados por razões independentes do presente estudo. Os espécimes foram divididos em dois grupos de acordo a técnica empregada e avaliados radiograficamente para mensuração do comprimento femoral e valores de ângulo de inclinação do colo femoral, ângulo femoral proximal lateral mecânico, ângulo femoral proximal lateral anatômico, ângulo femoral distal lateral mecânico, ângulo femoral distal lateral anatômico e ângulo de anteversão do colo femoral. Posteriormente, foram realizados os ensaios mecânicos para determinação da resistência em ambos os grupos. As avaliações radiográficas demonstraram a efetividade de ambos os métodos na varização do fêmur proximal. A técnica de osteotomia varizante em cúpula mostrou valores de resistência mecânica e modo de falência dos implantes empregados na osteossíntese comparados à técnica de osteotomia intertrocantérica varizante em cunha. Os testes biomecânicos demonstram a exeqüibilidade da técnica de osteotomia varizante em cúpula como alternativa ao tratamento da displasia coxofemoral em cães / The present study compares a new varus dome osteotomy technique to the traditional femoral varus intertrochanteric osteotomy in dogs. Ten pairs of femurs were used from dogs euthanized due to reasons unrelated to our study. The specimens were divided in two groups according to the technique and radiographically assessed to measure femoral length and femoral neck inclination angle, mechanical lateral proximal femoral angle, anatomical lateral proximal femoral angle, mechanical lateral distal femoral angle, anatomical lateral distal femoral angle and femoral neck anteversion angle values. Mechanical assays were then performed to determine resistance in both groups. The radiographic assessments showed the effectiveness of both methods in varization of the canine proximal femur. The varus dome osteotomy technique showed mechanical resistance values and failure mechanism of the systems similar when compared to varus wedge intertrochanteric osteotomy. The biomechanical tests demonstrated the varus dome osteotomy technique feasibility as an alternative for coxofemoral dysplasia treatment in dogs

O presente estudo compara uma nova técnica de osteotomia varizante em cúpula à tradicional osteotomia intertrocantérica varizante do fêmur em cadáveres de cães. Foram utilizados 10 pares de fêmures, provenientes de cães eutanasiados por razões independentes do presente estudo. Os espécimes foram divididos em dois grupos de acordo a técnica empregada e avaliados radiograficamente para mensuração do comprimento femoral e valores de ângulo de inclinação do colo femoral, ângulo femoral proximal lateral mecânico, ângulo femoral proximal lateral anatômico, ângulo femoral distal lateral mecânico, ângulo femoral distal lateral anatômico e ângulo de anteversão do colo femoral. Posteriormente, foram realizados os ensaios mecânicos para determinação da resistência em ambos os grupos. As avaliações radiográficas demonstraram a efetividade de ambos os métodos na varização do fêmur proximal. A técnica de osteotomia varizante em cúpula mostrou valores de resistência mecânica e modo de falência dos implantes empregados na osteossíntese comparados à técnica de osteotomia intertrocantérica varizante em cunha. Os testes biomecânicos demonstram a exeqüibilidade da técnica de osteotomia varizante em cúpula como alternativa ao tratamento da displasia coxofemoral em cães / The present study compares a new varus dome osteotomy technique to the traditional femoral varus intertrochanteric osteotomy in dogs. Ten pairs of femurs were used from dogs euthanized due to reasons unrelated to our study. The specimens were divided in two groups according to the technique and radiographically assessed to measure femoral length and femoral neck inclination angle, mechanical lateral proximal femoral angle, anatomical lateral proximal femoral angle, mechanical lateral distal femoral angle, anatomical lateral distal femoral angle and femoral neck anteversion angle values. Mechanical assays were then performed to determine resistance in both groups. The radiographic assessments showed the effectiveness of both methods in varization of the canine proximal femur. The varus dome osteotomy technique showed mechanical resistance values and failure mechanism of the systems similar when compared to varus wedge intertrochanteric osteotomy. The biomechanical tests demonstrated the varus dome osteotomy technique feasibility as an alternative for coxofemoral dysplasia treatment in dogs