Rotational assessment of distal femur and its relevance in total knee arthroplasty: analysis by magnetic resonance imaging

Loures, Fabrício Bolpato; Neto, Sebastião Furtado; Pinto, Robson de Lima; Kinder, André; Labronici, Pedro José; Góes, Rogério Franco de Araújo; Marchiori, Edson

doi:10.1590/0100-3984.2014.0037

Cited by 13 publications

(12 citation statements)

References 21 publications

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“…Variations in coronal and sagittal alignment have been widely documented. Variations in axial, or rotational, alignment have been indicated in several previous studies (Viel et al, 2013;Amaranath et al, 2014Loures et al, 2015;Jones et al, 2016). The advantage of this study is that it uses a more accurate technique for measuring the rotational alignment of the trochlear groove.…”

Section: Discussionmentioning

confidence: 87%

Femoral rotational asymmetry is a common anatomical variant

2018

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The sulcus line (SL) is a three-dimensional landmark that corrects for individual variation in the coronal alignment of the trochlear groove in contrast to the traditional Whiteside's line (WL). Femoral rotational asymmetry (FRA) is an anatomical variation in which the posterior condyles and trochlear groove are not perpendicular to each other. This study aims to measure the SL and assess its reliability relative to WL, in addition to measuring and classifying the FRA. A retrospective analysis of a series of 191 CT scans of nonarthritic knees was performed. Measurements were taken of rotational landmarks in three-dimensional reconstructions. The variability and outlier rate of SL was less than WL (P < 0.05), however, it was also greater than the posterior condylar line (PC) (P < 0.05). Averaging the PC + 3° and the SL did not change the rate of femoral malrotation relative to the surgical epicondylar axis (SEA) (P > 0.05), however it decreased the rate of change of the rotational alignment of the trochlear groove between the native knee and the prosthetic knee from 31% to 5% (P < 0.05). FRA was classified and was >5° in 56/191 (29%) of cases. The SL technique is more accurate than WL for determining the rotational alignment of the trochlear groove. Nonarthritic femora have a high rate of rotational asymmetry. Identifying and classifying FRA in individual cases allows the femoral component to be inserted in a position which gives the best possible match to both the native posterior condyles and trochlear groove. Clin. Anat. 31:551-559, 2018. © 2018 Wiley Periodicals, Inc.

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Section: Discussionmentioning

confidence: 87%

Femoral rotational asymmetry is a common anatomical variant

2018

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“…Jones et al [ 38 ] used MRI scans and found that “only 24% had an external rotation angle between 2.5° and 3.5° relative to” the posterior condyles. Loures et al [ 24 ] measured a range of 11.75° for the PCL and 14.29° for the APA on MRI scans. Theinpont et al [ 20 ] looked at 2637 3D reconstructions of preoperative CT scans and predicted a “41% risk of malalignment” from referencing the posterior condyles.…”

Section: Discussionmentioning

confidence: 99%

“…There is some research to suggest that on average, the axes are close to parallel [ 18 , 19 ]. However, the relationship is not consistent, with a wide range of variation [ 20 – 24 ].…”

Section: Introductionmentioning

confidence: 99%

Averaging rotational landmarks during total knee arthroplasty reduces component malrotation caused by femoral asymmetry

Chao¹,

Geraghty²,

Dimitriou³

et al. 2017

J Orthop Surg Res

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BackgroundFemoral component malrotation is a common cause of patient dissatisfaction after total knee arthroplasty. The sulcus line (SL) is more accurate than Whiteside’s line as it corrects for variation in the coronal orientation of the groove. The hypothesis is that averaging the SL and posterior condylar axis (PCA) will reduce femoral malrotation.MethodsThe component was inserted at a position between the SL and PCA in 91 patients. An intraoperative photograph was taken showing the landmarks. These were compared to the component position achieved relative to the surgical epicondylar axis (SEA) on a postoperative CT scan. The component position was compared to the position achieved using the individual landmarks.ResultsRelative to the SEA, the final component position was 0.6° (SD 1.4°, range −3.8° to +4.0°), the coronally corrected SL position was −0.7° (SD 2.3°, −5.5° to +4.6°), the PCA position was 0.9° (SD 1.9°, −6.1° to +5.0°). Averaging the landmarks significantly decreased the variance of the component position compared to using the SL and PCA individually. The number of outliers (>3° from SEA) was also significantly less (p < 0.05) for the average position (2/84) when each was compared to the SL (16/84) and PCA (14/84) individually. In 21/84 (25%) of cases, there was more than 4° of divergence between the SL and PCA.ConclusionsAveraging the SL and the PCA decreases femoral component malrotation. Femora are frequently asymmetrical in the axial plane. Referencing posterior condyles alone to set rotation is likely to cause high rates of patellofemoral malalignment.

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“…They found great variability in the shape of the distal femur, and more than 40% of the patients presented dimensions smaller than those of the implants available. However, as described by Loures et al ( 31 ) and Voleti et al ( 32 ) , CT does not consider the thickness of the articular cartilage, which limits the applicability of the method not only in the comparison with the implants but also in the definition of the anatomical standards.…”

Section: Discussionmentioning

confidence: 99%

Anthropometric study of the knee in patients with osteoarthritis: intraoperative measurement versus magnetic resonance imaging

Loures

Carrara

Góes³

et al. 2017

Radiol Bras

Self Cite

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Objective:To compare intraoperative measurements of the knee with those obtained by magnetic resonance imaging, in order to validate the latter method for use in anthropometric studies.Materials and Methods:We studied 20 knees in 20 patients with osteoarthritis, all of whom underwent total arthroplasty between August and December of 2013. We took six measurements in the distal femur and two in the proximal tibia. Using the information system of the institution, we made the measurements on magnetic resonance imaging scans that had been obtained in the axial plane. Intraoperative measurements were obtained using a caliper, after the initial cuts made during the arthroplasty. The anatomical parameters determined by magnetic resonance imaging were the same as those determined by intraoperative measurement. The intraclass correlation coefficient was used in order to assess the level of agreement in anthropometric measurements of the knee performed by magnetic resonance imaging and by intraoperative measurement.Results:Statistical analysis revealed a highly significant correlation between the knee anthropometric parameters of the knee determined by intraoperative measurement and those determined by magnetic resonance imaging.Conclusion:The dimensions of osteoarthritic knees measured by magnetic resonance imaging were similar to those measured intraoperatively. Therefore, magnetic resonance imaging can be considered a reliable method for use in large-scale anthropometric studies that will allow the available implants to be adapted and improved.

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Rotational assessment of distal femur and its relevance in total knee arthroplasty: analysis by magnetic resonance imaging

Cited by 13 publications

References 21 publications

Femoral rotational asymmetry is a common anatomical variant

Femoral rotational asymmetry is a common anatomical variant

Averaging rotational landmarks during total knee arthroplasty reduces component malrotation caused by femoral asymmetry

Anthropometric study of the knee in patients with osteoarthritis: intraoperative measurement versus magnetic resonance imaging

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