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Category: Hindfoot, Trauma Introduction/Purpose: The axial alignment of the calcaneus has paramount importance in the management of these fractures. The Harris view has long stood as the recommended radiograph to assess axial alignment. However, given the obliquity at which the radiograph is obtained, it doesn´t represent a true axial view and is subject to inaccuracies secondary to rotational malpositioning of the foot and mismeasurement of angulation. Multiple reports have described the axial alignment as a surgical outcome, but usually this assessment of the residual deformity have no described method. The objectives of this study are to evaluate the capacity of Harris view to assess axial alignment in a cadaveric model and to describe the use of a true AP view of the calcaneus that we have named Captain´s view. Methods: Five below knee amputated fresh-frozen cadaveric specimens were used in the study. For each specimen, the soft tissues over the lateral side were removed to access to the lateral wall. A small wedge of the cuboid was removed to visualize the center of the calcaneocuboid articular surface. LCA-guide and a cannulated drill were used to create a tunnel in the axis of the calcaneus. An oblique osteotomy was performed in order to simulate a non-comminuted fracture. Varus deformity was created by inserting solid radiolucent wedges into the osteotomy to create models of 10, 20, and 30 degrees of varus angulation. Harris and Captain views were obtained for each specimen with 0 (control), 10, 20, and 30 degrees of varus malalignment. Measurements of the deformity were made digitally on each fluoroscopic image. Results: The average degrees of varus in Harris views were 10,9 (5,5-16); 11,5 (8,2-13,6); and 18,3 (13,3-23,6) for 10,20 and 30 degrees of deformity respectively. The average degrees of varus in Captain´s view were 13,0 (7,3-20,9); 18,4 (11,7-23,5); and 28,2 (24,4-31,1) for 10,20 and 30 degrees of deformity respectively. The average degrees of error for varus deformity in Harris views were 4,1 (41%); 8,4 (42%) and 11,6 (39%) for 10,20 and 30 degrees of deformity respectively. The average degrees of error for varus deformity in Captain´s views were 4,8 (48%); 3,6 (18%) and 2,8 (8%) for 10,20 and 30 degrees of deformity respectively. Conclusion: The results of this study show a high rate of mismeasurement for both radiographic views. Despite the average angles have a clear correlation with the severity of varus, the wide range of error observed between specimens make this assessment unreliable and inaccurate. We observed an improvement of accuracy of captain´s view for more severe deformities, but not with Harris views which maintain a 40% mismeasurement in all the settings. Therefore, intraoperative Harris views should not be used in isolation to evaluate axial alignment and Captain´s view provides an additional perspective that can be useful to rule out severe deformities.

High tibial osteotomy (HTO) may be performed in association with anterior cruciate ligament (ACL) reconstruction/revision in patients with medial osteoarthritis, varus malalignment, and anterior instability. Furthermore, it may be performed in patients with varus alignment and increased posterior tibial slope (exceeding 12°), because it is related to an increased risk for ACL failure. There are different techniques to perform HTO, and consequently, a concomitant HTO and ACL reconstruction/revision. This article describes the indication, surgical techniques, and outcomes of concomitant HTO and ACL reconstruction/revision.

Painful loading of the knee during walking is a key feature of knee osteoarthritis (OA). The external knee moments derived from three-dimensional gait analysis represent dynamic knee loads and may help evaluate surgical interventions. However, the relationships between knee moments and pain and the effects of surgery remain unclear. The overall purpose of this thesis was to investigate knee moments and pain during walking in patients with moderate medial knee OA, including the effects of limb realignment and ligament reconstruction surgeries. This thesis includes three studies investigating knee moments in patients with medial compartment tibiofemoral OA. Chapter 2 describes a cross-sectional study examining the relationship between knee pain and knee moments during walking, while controlling for extraneous factors by comparing limbs within 265 patients with medial knee OA. Using conditional logistic regression, results indicated greater odds of an increase in pain during walking with increased knee adduction moment, adduction impulse and internal rotation moment, and decreased knee flexion moment. These findings suggest a strong relationship between knee moments (in all three planes of motion) and knee pain during walking when between-person confounding is lessened. Chapter 3 describes a prospective cohort study evaluating the bilateral changes in knee moments in all three planes of motion in 33 patients undergoing combined medial opening-wedge high tibial osteotomy (HTO) and anterior cruciate ligament (ACL) reconstruction (HTO-ACLR). Patients underwent three-dimensional gait analysis, patient-reported outcomes and radiographic analysis preoperatively, 2 years postoperatively and a minimum 5 years postoperatively. Results indicated significant reductions in the knee adduction and internal rotation moments in the surgical limb, and a decrease in the knee flexion moment and an increase in the knee extension moment in both limbs. Changes in only the surgical limb suggest that HTO-ACLR reduces frontal and transverse plane knee moments. Bilateral changes suggest the passage of time, rather than the surgery, is responsible for the changes in sagittal plane knee moments. Chapter 4 describes a retrospective matched cohort study comparing preoperative and 5-year postoperative changes in the knee adduction and flexion moments in 52 patients who underwent either combined HTO-ACLR or HTO-Alone. Results indicated that both groups experienced a significant reduction in the knee adduction moment in the surgical limb. However, the HTO-Alone group also experienced a significant decrease in the knee flexion moment while the HTO-ACLR group experienced no change in sagittal plane knee moments. These findings suggest that HTO-ACLR may lessen the long-term decrease in the knee flexion moment typically observed over time in patients with knee OA. Overall, the results of this thesis support the use of investigating bilateral knee moments during walking in patients with medial knee OA, and provide rationale for future research examining whether the biomechanical changes observed in these individuals affects OA progression.

Restoration of neutral mechanical alignment is one of the prerequisites for long-term TKA survival. This study aimed to investigate the effect of deviations from neutral alignment on bone and implant stress and on ligament strain. Using a previously validated finite element model, a neutrally aligned TKA model was compared to 3 different varus and valgus configurations induced by tibial or by femoral component only and by both component simultaneously. Each model underwent a 2500 N vertical load simulating the peak walking force. Varus and valgus alignment increased polyethylene and bone stress, and altered ligament strains, as compared to the neutral aligned model. Changes in alignment of the tibial component were always associated with more detrimental effects compared to the one of the femoral component.

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

To prospectively investigate whether preoperative functional flexion axis in patients with osteoarthritis- and varus-alignment changes after total knee arthroplasty and whether a correlation exists both between preoperative functional flexion axis and native limb deformity. A navigated total knee arthroplasty was performed in 108 patients using a specific software to acquire passive joint kinematics before and after implant positioning. The knee was cycled through three passive range of motions, from 0° to 120°. Functional flexion axis was computed using the mean helical axis algorithm. The angle between the functional flexion axis and the surgical transepicondylar axis was determined on frontal (α F) and axial (α A) plane. The pre- and postoperative hip-knee-ankle angle, related to femur mechanical axis, was determined. Postoperative functional flexion axis was different from preoperative only on frontal plane, while no differences were found on axial plane. No correlation was found between preoperative α A and native limb deformity, while a poor correlation was found in frontal plane, between α F and preoperative hip-knee-ankle angle. Total knee arthroplasty affects functional flexion axis only on frontal plane while has no effect on axial plane. Preoperative functional flexion axis is in a more varus position respect to the transepicondylar axis both in pre- and postoperative conditions. Moreover, the position of the functional axis on frontal plane in preoperative conditions is dependent on native limb alignment, while on axial plane is not dependent on the amount of preoperative varus deformity. IV.

A retrospective review was conducted to evaluate the mid-term results (8.5 years follow-up) of the Versys ET stem (Zimmer, Warsaw, Indiana, USA). From 1995 to 2000, 225 total hip arthroplasties (THA) were performed using this device. All patients were evaluated clinically by the Harris Hip Score, and radiographically. The Hip Score increased from 54 preoperatively to 97 points postoperatively. The stem displayed a varus alignment between 5° and 10° in 17 cases without any clinical consequences (HHS 96.8). We recorded one case of septic loosening and one case of aseptic loosening. The stability of the stem was radiographically evaluated according to Engh's criteria, confirming bone ongrowth in all other cases.

Methods of designing equipment to improve quality have been developed by Taguchi. A key feature of these methods is the development of loss function, which quantifies the financial cost (loss) resulting from deviations from target dimensions. Total knee arthroplasties can fail due to prosthetic component malalignment. A Taguchi loss function for varus/valgus alignment of the prosthesis and revision rates was developed. Six studies were identified from a comprehensive literature search. Varus and extreme valgus alignments correlated with an increased percentage of prosthetic failure. A loss function ofL(y) = $326.80y2, where y was deviation from ideal varus/valgus angle, was determined. The expected loss function was E L = $ 326.80 y 2 s 2 , where y was the mean deviance from the ideal varus/valgus angle ands2 was the variance in varus/valgus angle. This loss function was used to estimate the cost savings of using computer-assisted surgical navigation in total knee arthroplasty (TKA). The average savings of a navigated TKAversus a conventional TKA, based on the expected loss equation derived from the Taguchi loss function, was $2,304 per knee. The expected loss function derived here can serve as a tool for biomedical engineers seeking to use Taguchi quality engineering methods in designing orthopaedic devices.