WEIGHT-BEARING CONE BEAM CT SCANS AND ITS USES IN ANKLE, FOOT, AND KNEE: AN UPDATE ARTICLE

ABSTRACT Imaging plays a key role in the preoperative diagnosis, surgical planning, and postsurgical assessment of the foot, ankle, and knee pathologies. Interpreting diagnostic imaging accurately is crucial for the clinical practice of orthopedic surgeons. Although among the most used imaging modalities, radiographic assessments are amenable to errors for various technical reasons and superposition of bones. Computed tomography (CT) is a conventional imaging procedure that provides high-resolution images, but fails in considering a truly weight-bearing (WB) condition. In an attempt to overcome this limitation, WB cone beam CT technology has being successfully employed in the clinical practice for the past decade. Besides economically viable and safe, the WB cone beam CT considers WB conditions and provides high-quality scans, thus allowing an equitable and correct interpretation. This review aims to address extensive description and discussion on WBCT, including imaging quality; costs; time consumption; and its applicability in common foot, ankle, and knee, conditions. With this technology increasing popularity, and considering the extensive literature on medical research, radiologists and orthopedic surgeons need to understand its potential applications and use it optimally. Level of Evidence III, Systematic review of level III studies.

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Weight Bearing CT and Relative Orientation of Foot Bones: Effect of Loading and Heeled Shoes

Journal of Advanced Health Care ◽

10.36017/jahc2004-004 ◽

2020 ◽

pp. 10-14

Author(s):

Sandu Elena Cerasela ◽

Caravaggi Paolo ◽

Durante Stefano

Keyword(s):

Sagittal Plane ◽

Cone Beam Ct ◽

Young Subject ◽

Weight Bearing ◽

Cone Beam ◽

Non Invasive ◽

Foot Bones ◽

Healthy Young Subject ◽

Foot Posture ◽

Metatarsophalangeal Joints

The purpose of this article is to determine the orientation and relative position of the foot bones in Weight Bearing CT, highlighting the effect of the load and the shoe with the heel. Thanks to a Cone Beam CT (OnSight 3D Extremity System, Carestream) equipment, three scans of the foot of a healthy young subject were carried out in three conditions: "unloading", "loading", and wearing a shoe with "heel". In order to assess the accuracy of the articular angles of the foot through non-invasive measurements, a measurement was performed by Gait-Analysis with passive markers in the same conditions. The effect of the "load" resulted in a significant alteration of the foot posture especially in the sagittal plane, with crushing of the longitudinal medial arch. The heeled shoe involves enormous deformations at the level of the metatarsophalangeal joints and the ankle.

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3D Assessment in Posttraumatic Ankle Osteoarthritis

Foot & Ankle International ◽

10.1177/1071100720961315 ◽

2020 ◽

pp. 107110072096131

Author(s):

Peter Kvarda ◽

Lukas Heisler ◽

Nicola Krähenbühl ◽

Caspar Samuel Steiner ◽

Roxa Ruiz ◽

...

Keyword(s):

Ct Scan ◽

Cone Beam Ct ◽

Varus Deformity ◽

Valgus Deformity ◽

Cone Beam ◽

Healthy Individuals ◽

Ankle Osteoarthritis ◽

Level Of Evidence ◽

3D Measurements ◽

End Stage

Introduction: Auto-generated 3-dimensional (3D) measurements based on weightbearing cone-beam computed tomography (CT) scan technology may allow for a more accurate hind- and midfoot assessment. The current study evaluated the reliability and clinical relevance of such measurements in patients with posttraumatic end-stage ankle osteoarthritis. Methods: Seventy-two patients treated at our institution for posttraumatic end-stage ankle osteoarthritis, with available weightbearing conventional radiographs and a cone-beam CT scan, were analyzed. Twenty healthy individuals aged between 40 and 70 years served as controls. Seven variables were measured on weightbearing conventional radiographs (2D) and compared to 3D measurements that were based on reconstructions from weightbearing cone-beam CT scans. The reliability of each measurement was calculated and subgroups formed according to commonly observed deformities. Results: Inter- and intraobserver reliability was superior for 3D compared to 2D measurements. The accuracy of 3D measurements performed on osteoarthritic ankles was similar to 3D measurements performed on healthy individuals. Thirty-three of the 72 included patients (46%) evidenced an inframalleolar compensation of a supramalleolar/intra-articular ankle deformity (78% = varus compensation; 22% = valgus compensation), whereas 24 of those 72 patients (33%) showed no compensation or a further increase of a supramalleolar/intra-articular ankle deformity (67% = varus deformity; 33% = valgus deformity). Conclusion: Auto-generated 3D measurements of the hind- and midfoot were found to be reliable in both healthy individuals and patients with posttraumatic end-stage ankle osteoarthritis. Such measurements may be crucial for a detailed understanding of the location and extent of hindfoot deformities, possibly impacting decision making in the treatment of end-stage ankle osteoarthritis. Level of Evidence: Level III, comparative study.

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A robotic x-ray cone-beam CT system: trajectory optimization for 3D imaging of the weight-bearing spine

Medical Imaging 2019: Physics of Medical Imaging ◽

10.1117/12.2513433 ◽

2019 ◽

Cited By ~ 1

Author(s):

Chumin Zhao ◽

Magdalena Herbst ◽

Sebastian Vogt ◽

Ludwig Ritschl ◽

Steffen Kappler ◽

...

Keyword(s):

Trajectory Optimization ◽

3D Imaging ◽

Cone Beam Ct ◽

Weight Bearing ◽

Cone Beam ◽

X Ray ◽

System Trajectory ◽

Ct System

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Weight-Bearing Cone-Beam CT Scan Assessment of Stability of Supination External Rotation Ankle Fractures in a Cadaver Model

Foot & Ankle International ◽

10.1177/1071100718761035 ◽

2018 ◽

Vol 39 (7) ◽

pp. 850-857 ◽

Cited By ~ 14

Author(s):

Mark C. Lawlor ◽

Melissa A. Kluczynski ◽

John M. Marzo

Keyword(s):

Ct Scan ◽

Ankle Fracture ◽

External Rotation ◽

Imaging Modality ◽

Cone Beam Ct ◽

Weight Bearing ◽

Ankle Fractures ◽

Cone Beam ◽

Clear Space ◽

Supination External Rotation

Background: The utility of computed tomography (CT) for measuring medial clear space (MCS) for determination of the stability of supination external rotation (SER) ankle fractures and in comparison to standard radiographs is unknown. We compared MCS on gravity stress (GS) radiographs to GS and weight bearing (WB) cone-beam CT (CBCT). Methods: An AO SER 44B3.1 ankle fracture was simulated in 10 human cadavers, also serving as controls. MCS was measured on GS radiographs, GS CBCT, and a simulated WB CBCT scan. Specimens were stable if MCS was <5 mm and unstable if MCS was ≥5 mm. Paired t tests were used to compare MCS from each imaging modality for controls versus SER injuries and stable versus unstable specimens. Results: Compared with controls assessed by GS radiographs, MCS was greater for an SER injury when assessed by GS radiograph and GS CBCT scan within the stable group. Compared with controls assessed by GS radiographs, MCS was greater for SER injuries when assessed by GS radiograph, GS CBCT scan, and WB CBCT within the unstable group. MCS was reduced for stable versus unstable SER injuries assessed by WB CBCT. Conclusion: In a cadaveric model of SER ankle fracture, the medial clear space was statistically significantly greater for the experimental condition when assessed by gravity stress radiograph and gravity stress CBCT scan. Under weight-bearing conditions, the cone-beam CT scanner distinguished between stable and unstable ankles in the experimental condition. Clinical Relevance: This study suggests that a WB cone-beam CT scan may be able to distinguish between stable and unstable SER ankle fractures and influence operative decision making.

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Abstract: Inertial Measurements for Motion Compensation in Weight-bearing Cone-beam CT of the Knee

Bildverarbeitung für die Medizin 2021 - Informatik aktuell ◽

10.1007/978-3-658-33198-6_81 ◽

2021 ◽

pp. 336-336

Author(s):

Jennifer Maier ◽

Marlies Nitschke ◽

Jang-Hwan Choi ◽

Garry Gold ◽

Rebecca Fahrig ◽

...

Keyword(s):

Motion Compensation ◽

Cone Beam Ct ◽

Weight Bearing ◽

Cone Beam ◽

Inertial Measurements

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Cone-beam CT measurements of distal tibio-fibular syndesmosis in asymptomatic uninjured ankles: does weight-bearing matter?

Skeletal Radiology ◽

10.1007/s00256-018-3074-6 ◽

2018 ◽

Vol 48 (4) ◽

pp. 583-594 ◽

Cited By ~ 18

Author(s):

Delaram Shakoor ◽

Greg M. Osgood ◽

Michael Brehler ◽

Wojciech B. Zbijewski ◽

Cesar de Cesar Netto ◽

...

Keyword(s):

Cone Beam Ct ◽

Weight Bearing ◽

Cone Beam ◽

Ct Measurements

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Defining reference values for the normal tibiofibular syndesmosis in adults using weight-bearing CT

The Bone & Joint Journal ◽

10.1302/0301-620x.101b3.bjj-2018-0829.r1 ◽

2019 ◽

Vol 101-B (3) ◽

pp. 348-352 ◽

Cited By ~ 17

Author(s):

S. Patel ◽

K. Malhotra ◽

N. P. Cullen ◽

D. Singh ◽

A. J. Goldberg ◽

...

Keyword(s):

Cone Beam Ct ◽

Weight Bearing ◽

Cone Beam ◽

Syndesmotic Injury ◽

Tibiofibular Syndesmosis ◽

Cross Sectional ◽

Female Patients ◽

Normal Ranges ◽

Anteroposterior Translation ◽

The Mean

Aims Cone beam CT allows cross-sectional imaging of the tibiofibular syndesmosis while the patient bears weight. This may facilitate more accurate and reliable investigation of injuries to, and reconstruction of, the syndesmosis but normal ranges of measurements are required first. The purpose of this study was to establish: 1) the normal reference measurements of the syndesmosis; 2) if side-to-side variations exist in syndesmotic anatomy; 3) if age affects syndesmotic anatomy; and 4) if the syndesmotic anatomy differs between male and female patients in weight-bearing cone beam CT views. Patients and Methods A retrospective analysis was undertaken of 50 male and 50 female patients (200 feet) aged 18 years or more, who underwent bilateral, simultaneous imaging of their lower legs while standing in an upright, weight-bearing position in a pedCAT machine between June 2013 and July 2017. At the time of imaging, the mean age of male patients was 47.1 years (18 to 72) and the mean age of female patients was 57.8 years (18 to 83). We employed a previously described technique to obtain six lengths and one angle, as well as calculating three further measurements, to provide information on the relationship between the fibula and tibia with respect to translation and rotation. Results The upper limit of lateral translation in un-injured patients was 5.27 mm, so values higher than this may be indicative of syndesmotic injury. Anteroposterior translation lay within the ranges 0.31 mm to 2.59 mm, and -1.48 mm to 3.44 mm, respectively. There was no difference between right and left legs. Increasing age was associated with a reduction in lateral translation. The fibulae of men were significantly more laterally translated but data were inconsistent for rotation and anteroposterior translation. Conclusion We have established normal ranges for measurements in cross-sectional syndesmotic anatomy during weight-bearing and also established that no differences exist between right and left legs in patients without syndesmotic injury. Age and gender do, however, affect the anatomy of the syndesmosis, which should be taken into account at time of assessment. Cite this article: Bone Joint J 2019;101-B:348–352.

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Are Weightbearing Restrictions Required After Microfracture for Isolated Chondral Lesions of the Knee? A Review of the Basic Science and Clinical Literature

Sports Health A Multidisciplinary Approach ◽

10.1177/1941738120938662 ◽

2020 ◽

pp. 194173812093866

Author(s):

Deeptee Jain ◽

Elshaday S. Belay ◽

John A. Anderson ◽

William E. Garrett ◽

Brian C. Lau

Keyword(s):

Literature Review ◽

Clinical Studies ◽

Basic Science ◽

Weight Bearing ◽

Extensive Literature ◽

Retrospective Case ◽

Level Of Evidence ◽

Chondral Lesions ◽

Clinical Literature ◽

Significant Disability

Context: A strict rehabilitation protocol is traditionally followed after microfracture, including weightbearing restrictions for 2 to 6 weeks. However, such restrictions pose significant disability, especially in a patient population that is younger and more active. Evidence Acquisition: An extensive literature review was performed through PubMed and Google Scholar of all studies through December 2018 related to microfracture, including biomechanical, basic science, and clinical studies. For inclusion, clinical studies had to report weightbearing status and outcomes with a minimum 12-month follow-up. Study Design: Clinical review. Level of Evidence: Level 3. Results: Review of biomechanical and biology studies suggest new forming repair tissue is protected from shear forces of knee joint loading by the cartilaginous margins of the defect. This margin acts as a shoulder to maintain axial height and allow for tissue remodeling up to at least 12 months after surgery, well beyond current weight bearing restriction trends. A retrospective case-control study showed that weightbearing status postoperatively had no effect on clinical outcomes in patients who underwent microfracture for small chondral (<2 mm2) defects. In fact, 1 survey showed that many orthopaedic surgeons currently do not restrict weightbearing after microfracture. Conclusion: This clinical literature review suggests that weightbearing restrictions may not be required after microfracture for isolated tibiofemoral chondral lesions of the knee. Strength of Recommendation Taxonomy: C.

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