Upright CT of the knee: the effect of weight-bearing on joint alignment

Hirschmann, Anna; Buck, Florian M.; Fucentese, Sandro F.; Pfirrmann, Christian W. A.

doi:10.1007/s00330-015-3756-6

Cited by 51 publications

(60 citation statements)

References 24 publications

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“…The significantly lower value of the TT-TG offset raises the question of establishing a new threshold for CT examinations under physiological, upright weightbearing and functional positioning when evaluating patellofemoral diseases and contemplating surgery for malalignment. 16 , 22 …”

Section: Discussionmentioning

confidence: 99%

“…Conventional CT scans of the knee are acquired with the patient in a supine, nonweightbearing position, but limitations of this technique have been reported. 16 , 22 New CT systems, including the On-Sight cone-beam CT scanner (Carestream Health), are available to acquire images while the patient is standing and to allow various positions of knee flexion and extension. 11 , 22 , 33 It has been shown that knee position and weightbearing can independently affect the TT-TG offset distance.…”

mentioning

confidence: 99%

“… 11 , 22 , 33 It has been shown that knee position and weightbearing can independently affect the TT-TG offset distance. 2 , 12 , 16 , 22 , 32 , 37 …”

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confidence: 99%

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Measurement of Tibial Tuberosity–Trochlear Groove Offset Distance by Weightbearing Cone-Beam Computed Tomography Scan

Marzo

Kluczynski

Notino

et al. 2017

Orthopaedic Journal of Sports Medicine

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Background:Computed tomography (CT) scans are useful for objectively measuring bone alignment because they show bone detail particularly well, and these scans have been used extensively to assess patellar orientation. The tibial tubercle–trochlear groove (TT-TG) offset distance has been shown to be influenced by knee flexion and weightbearing, yet conventional CT scans are obtained with the subject relaxed, supine, and with the knee in full extension. A new cone-beam CT scanner has been designed to allow for weightbearing images, potentially providing a more physiologically relevant assessment of patellofemoral alignment.Purpose/Hypothesis:The purpose of this study was to measure the TT-TG offset in healthy individuals without any history of knee complaints when CT scans were obtained while fully weightbearing on a flexed knee. Our hypothesis was that the TT-TG offset measurement in these healthy knees would be reproducible and less than the historically reported normal range.Study Design:Cross-sectional study; Level of evidence, 3.Methods:Twenty healthy volunteers without any history of knee complaint were recruited to undergo a weightbearing cone-beam CT scan of the knee flexed at 30°. The scans were reviewed by a radiologist and an orthopaedic surgeon, and TT-TG offset was measured using the digital tools of a picture archiving and communication system. Paired t tests were used to compare TT-TG offset on 2 separate occasions for both raters. Inter- and intrarater reliability were assessed using a 2-way mixed-effects model intraclass correlation coefficient with corresponding 95% confidence intervals for TT-TG offset.Results:The mean TT-TG offset was 2.7 mm. There were no statistically significant differences in TT-TG offset between raters (P rater1 = .70; P rater2 = .49) and time of read (P time1 = .83; P time2 = .19). Good to moderate interrater reliability was found at the time of both reads, and good intrarater reliability was found for both raters.Conclusion:When measured by CT scan and obtained from a subject while weightbearing on a flexed knee, the TT-TG offset is reproducible and the distance is less than that obtained via a conventional CT scan.

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Section: Discussionmentioning

confidence: 99%

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confidence: 99%

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Measurement of Tibial Tuberosity–Trochlear Groove Offset Distance by Weightbearing Cone-Beam Computed Tomography Scan

Marzo

Kluczynski

Notino

et al. 2017

Orthopaedic Journal of Sports Medicine

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“…Despite this variability, it is interesting to note that the tibiofemoral alignment, i.e. the angle between knee-parent and kneechild medio-lateral Z axis, was 5.7°±3.8° external rotation across all algorithms for the in vivo MRI datasets, which is compatible, although slightly larger, with the offset in tibiofemoral alignment observed by Hirschmann et al (2015) comparing upright and supine non-weight-bearing CT scans in 26 patients (2.7°±5.1° and 2.6°±5.6° external rotation, from two readers). This suggests that the automated methods could be used to correct tibial alignment offsets introduced in standard imaging, although further investigations are required to identify the most suited adjustment algorithm.…”

Section: Discussionmentioning

confidence: 54%

Automatic Generation of Personalised Skeletal Models of the Lower Limb from Three-Dimensional Bone Geometries

Modenese

Renault

2020

Preprint

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The generation of personalised and patient-specific musculoskeletal models is currently a cumbersome and time-consuming task that normally requires several processing hours and trained operators. We believe that this aspect discourages the use of computational models even when appropriate data are available and personalised biomechanical analysis would be beneficial. In this paper we present a computational tool that enables the fully automatic generation of skeletal models of the lower limb from three-dimensional bone geometries, normally obtained by segmentation of medical images. This tool was validated against four manually created lower limb models finding remarkable agreement in the computed joint parameters, well within human operator repeatability, with the only exception being the subtalar joint axis estimation, which was sensitive to the bone segmentation quality. To prove the robustness of the methodology, the models were built from datasets including both genders, anatomies ranging from juvenile to elderly and bone geometries reconstructed from high-quality computed tomography as well as lower-quality magnetic resonance imaging scans. The entire workflow, implemented in MATLAB scripting language, executed in seconds and required no operator intervention, creating lower extremity models ready to use for kinematic and kinetic analysis or as baselines for more advanced musculoskeletal modelling approaches, of which we provide some practical examples. We auspicate that this technical advancement will promote the use of personalised models in larger-scale studies than those hitherto undertaken.

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“…It has been shown that joint articulation varies in the standing patient position compared to when the patient is in a prone or supine position. 3,4 Diagnosis of musculoskeletal disorders can benefit from images acquired in this natural standing position.…”

Section: Twin Robotic X-ray Systemmentioning

confidence: 99%

Twin robotic x-ray system for 2D radiographic and 3D cone-beam CT imaging

Fieselmann¹,

Steinbrener²,

Jerebko³

et al. 2016

SPIE Proceedings

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In this work, we provide an initial characterization of a novel twin robotic X-ray system. This system is equipped with two motor-driven telescopic arms carrying X-ray tube and flat-panel detector, respectively. 2D radiographs and fluoroscopic image sequences can be obtained from different viewing angles. Projection data for 3D conebeam CT reconstruction can be acquired during simultaneous movement of the arms along dedicated scanning trajectories. We provide an initial evaluation of the 3D image quality based on phantom scans and clinical images. Furthermore, initial evaluation of patient dose is conducted. The results show that the system delivers high image quality for a range of medical applications. In particular, high spatial resolution enables adequate visualization of bone structures. This system allows 3D X-ray scanning of patients in standing and weight-bearing position. It could enable new 2D/3D imaging workflows in musculoskeletal imaging and improve diagnosis of musculoskeletal disorders.

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Upright CT of the knee: the effect of weight-bearing on joint alignment

Cited by 51 publications

References 24 publications

Measurement of Tibial Tuberosity–Trochlear Groove Offset Distance by Weightbearing Cone-Beam Computed Tomography Scan

Measurement of Tibial Tuberosity–Trochlear Groove Offset Distance by Weightbearing Cone-Beam Computed Tomography Scan

Automatic Generation of Personalised Skeletal Models of the Lower Limb from Three-Dimensional Bone Geometries

Twin robotic x-ray system for 2D radiographic and 3D cone-beam CT imaging

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