Three-Dimensional Displacement after a Medializing Calcaneal Osteotomy in Relation to the Hindfoot Alignment and Osteotomy Angle

Category: Hindfoot Introduction/Purpose: An adult-acquired flatfoot deformity is a three-dimensional (3D) condition characterized by a loss of the medial longitudinal arch, valgus alignment of the hindfoot, and abduction of the midfoot. When conservative measures are not sufficient, a medializing calcaneal osteotomy (MCO) is frequently performed to correct the deformity, but there is lack of data on the associated three-dimensional variables defining the final correction. A possible reason for this shortcoming could be the current image-based analyses, mainly performed on bi-dimensional radiographs. These are hampered by errors in 3D rotations and superimposition of bony structures. The aim of this study was therefore to assess the correlation between the preoperative hindfoot valgus deformity and calcaneal osteotomy angle and the postoperative calcaneal displacement by use of weightbearing CT (WBCT). Methods: Weight-bearing CT scans obtained pre- and post-operatively were analyzed for sixteen patients with a mean age of 49.4 years (range: 18-66 years). Indication for surgery was adult-acquired flat foot deformity stage II. Based on the WBCT images, pre- and post-operative 3D bone morphological models of the tibia, talus, calcaneus, and the second metatarsal were created, on which anatomical bony landmarks were computationally identified to define a Foot Anatomical reference Frame (FAF). This FAF was used to measure valgus deformity pre- and post-operatively, inclination of the osteotomy plane, and displacement of the calcaneus (Fig. 1). Linear regression was conducted to assess the relationship between these measurements. Results: On average, the hindfoot valgus changed from 13.1° (±4.6) preoperatively to 5.7° (±4.3) postoperatively. A mean inferior displacement of 3.2 mm (±1.3) was observed along the osteotomy with a mean inclination angle of 54.6° (±5.6), 80.5° (±10.7), - 13.7° (±15.7) in the axial, sagittal and coronal planes, respectively. A statistically significant positive relationship (P < .05, R2 = 0.6) was found between the preoperative valgus, the axial osteotomy inclination, and the inferior displacement. Conclusion: This study shows that the degree of preoperative valgus of the hindfoot and the axial osteotomy angle are predictive factors for the amount of postoperative plantar displacement of the calcaneus. These findings contrast the general recommendation of performing a 90° calcaneal osteotomy angle, i.e. perpendicular to the lateral calcaneal wall in every patient. The obtained factors should be taken into account when performing a MCO and could be integrated in a computer-based pre- operative planning.

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Analysis of the Hindfoot Alignment Measured in 3D After a Medializing Calcaneal Osteotomy Using a Pre- and Postoperative Weightbearing CT

Foot & Ankle Orthopaedics ◽

10.1177/2473011418s00032 ◽

2018 ◽

Vol 3 (3) ◽

pp. 2473011418S0003

Author(s):

Arne Burssens ◽

Alexej Barg ◽

Timothy Leenders ◽

Stefan Clockaerts ◽

Peter Burssens ◽

...

Keyword(s):

Valgus Deformity ◽

Stage Ii ◽

Tibial Rotation ◽

Flat Foot ◽

Hindfoot Alignment ◽

Software Analysis ◽

Calcaneal Osteotomy ◽

Significant Difference ◽

Significant Correction ◽

The Mean

Category: Hindfoot Introduction/Purpose: An adult acquired flat foot (AAFD) is a complex 3D deformity. A medializing calcaneal osteotomy (MCO) is a surgical procedure frequently performed to correct the valgus alignment of the hindfoot in a stage II AAFD, when conservative measurements fail. However currently little is known on its accurate influence regarding the hindfoot alignment (HA). The aim is therefore to assess the influence of a MCO on the 3D HA using computer aided software analysis of the images retrieved from a weightbearing cone beam CT (WBCT). Methods: Twelve patients with a mean age of 49,4 years (range 18-67yrs) were prospectively included in a pre-post study design. Indications for surgical correction by a MCO with a solitary translation consisted of an AAFD stage II (N=10) and a posttraumatic valgus deformity (N=2). Fixation of the osteotomy was performed by a step-plate or double screw. WBCT was obtained pre- and post-operative. Images were subsequently segmented to allow a HA calculation in 3D(HA3D) by an angle between the anatomical tibia axis and the axis connecting the computed inferior calcaneuspoint and the centroid of the talus in the coronal plane based on a Cartesian coordinatesystem(Fig 1A, C). The tibia in the HA3D was separately assessed by the anatomical tibia axis (TAx 3D) and the axis to determine the tibial rotation(TR 3D) in the axial plane by connecting the computed most outer point of the anterior and posterior tubercle of the incisura fibularis(Fig 2A, D). Results: The mean medial translation of the calcaneal osteotomy during surgery was 5.72 mm (SD = 3.9). The mean HA3D pre-operatively equaled 18.21 degrees of valgus (SD = 6.6) and post-operatively 9.31 degrees of valgus (SD = 6.18). The Paired Student’s t-test showed a significant correction of 8.89 degrees (95%CI [5.99, 11.80], P<0.001). The mean TAX 3D pre-operatively was 6.80 degrees of valgus (SD = 3.38) and post-operatively 4.11 degrees of valgus (SD = 2.77), with a significant difference of 2.69 degrees (95%CI [1.79, 3.59], P <0.001). The mean TR3D pre-operatively was -27.11 degrees (SD = 4.77) and post-operatively - 28.80 degrees (SD = 5.98) and showed a significant difference of 1.69 degrees (95%CI [0.41, 2.97], P = 0,016). Conclusion: This study shows an effective correction of the valgus hindfoot in an AAFD. It appears that the correction is not only situated in the calcaneus but also to a lesser extent in the tibia and this resulted in 15% of the achieved HA correction. The novelty is the 3D weightbearing assessment of a hindfoot correction and the shown influence on the tibia. This information could be of use to take in to account when performing a pre-operative planning of a hindfoot deformity.

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An innovative Weight-Bearing Device for Weight-Bearing Three-Dimensional Imaging for Foot and Ankle Surgery Pre-operative Planning

The Journal of Foot & Ankle Surgery ◽

10.1053/j.jfas.2020.06.032 ◽

2021 ◽

Author(s):

J Ferràs-Tarragó ◽

E Grau-Llopis ◽

E Navarrete-Faubel ◽

M Sánchez-González ◽

V Vicent-Carsí

Keyword(s):

Weight Bearing ◽

Three Dimensional ◽

Foot And Ankle ◽

Three Dimensional Imaging ◽

Ankle Surgery ◽

Operative Planning

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Weight-bearing CT Technology in Musculoskeletal Pathologies of the Lower Limbs: Techniques, Initial Applications, and Preliminary Combinations with Gait-Analysis Measurements at the Istituto Ortopedico Rizzoli

Seminars in Musculoskeletal Radiology ◽

10.1055/s-0039-1697939 ◽

2019 ◽

Vol 23 (06) ◽

pp. 643-656 ◽

Cited By ~ 5

Author(s):

Alberto Leardini ◽

Stefano Durante ◽

Claudio Belvedere ◽

Paolo Caravaggi ◽

Claudio Carrara ◽

...

Keyword(s):

Weight Bearing ◽

Three Dimensional ◽

3D Models ◽

Two Dimensions ◽

Lower Limbs ◽

Flat Foot ◽

Musculoskeletal Radiology ◽

Foot Bones ◽

Patellofemoral Alignment ◽

3D Scans

AbstractMusculoskeletal radiology has been mostly limited by the option between imaging under load but in two dimensions (i.e., radiographs) and three-dimensional (3D) scans but in unloaded conditions (i.e., computed tomography [CT] and magnetic resonance imaging in a supine position). Cone-beam technology is now also a way to image the extremities with 3D and weight-bearing CT. This article discusses the initial experience over a few studies in progress at an orthopaedic center. The custom design of total ankle replacements, the patellofemoral alignment after medial ligament reconstruction, the overall architecture of the foot bones in the diabetic foot, and the radiographic assessment of the rearfoot after subtalar fusion for correction of severe flat foot have all taken advantage of the 3D and weight-bearing feature of relevant CT scans. To further support these novel assessments, techniques have been developed to obtain 3D models of the bones from the scans and to merge these with state-of-the-art gait analyses.

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Three-dimensional displacement after a medializing calcaneal osteotomy in relation to the osteotomy angle and hindfoot alignment

Foot and Ankle Surgery ◽

10.1016/j.fas.2018.11.015 ◽

2020 ◽

Vol 26 (1) ◽

pp. 78-84 ◽

Cited By ~ 1

Author(s):

M. Peiffer ◽

C. Belvedere ◽

S. Clockaerts ◽

T. Leenders ◽

A. Leardini ◽

...

Keyword(s):

Three Dimensional ◽

Hindfoot Alignment ◽

Calcaneal Osteotomy

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Three-Dimensional Starch Model for Simulation of Corrective Osteotomy for a Complex Bone Deformity: A Case Report

Foot & Ankle International ◽

10.1177/107110070302400411 ◽

2003 ◽

Vol 24 (4) ◽

pp. 364-367 ◽

Cited By ~ 7

Author(s):

Tominaga Shimizu ◽

Fumio Fujioka ◽

Hiroki Gomyo ◽

Kenichi Isobe ◽

Kunio Takaoka

Keyword(s):

Corrective Osteotomy ◽

Three Dimensional ◽

Limb Lengthening ◽

Valgus Deformity ◽

Bone Deformity ◽

Plastic Model ◽

Operative Planning ◽

Planning Technique ◽

The Right ◽

Tomography Data

The complex valgus deformity of the right ankle of a 24-year-old Maffucci syndrome man was corrected by three-dimensional osteotomy followed by limb lengthening. Before surgical correction of the deformity, we used computed tomography data to make a life-size three-dimensional plastic model of the deformed ankle for an accurate understanding of the anatomical deformity. We then used this model to perform a simulated osteotomy. The real osteotomy was performed immediately afterwards and valgus and recurvatum deformities were corrected accurately. We recommend simulated surgery using a three-dimensional plastic model which will improve the pre-operative planning technique and the accuracy of the end results.

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The Association Between a Hindfoot Deformity Assessed by Weightbearing CT and the Full Leg Alignment

Foot & Ankle Orthopaedics ◽

10.1177/2473011419s00014 ◽

2019 ◽

Vol 4 (4) ◽

pp. 2473011419S0001

Author(s):

Arne Burssens ◽

Kristian Buedts ◽

Alexej Barg ◽

Elizabeth Vluggen ◽

Patrick Demey ◽

...

Keyword(s):

Weight Bearing ◽

Varus Deformity ◽

Valgus Deformity ◽

Varus Alignment ◽

Hindfoot Alignment ◽

Leg Alignment ◽

Hindfoot Deformities ◽

Study Population ◽

Hindfoot Deformity ◽

Weightbearing Ct

Category: Hindfoot Introduction/Purpose: The exact relationship between different types of hindfoot deformities and the full leg alignment is currently unclear. Therefore, our aim is to assess hindfoot alignment on a weight-bearing CT (WBCT) and its association with the full leg radiographic alignment. Methods: A retrospective analysis was performed on a study population of 109 patients (mean age of 53 years ± 14.49) with a varus or valgus hindfoot deformity and the presence or absence of ankle osteoarthritis (OA) based on the Takakura classification. The mechanical hindfoot - (mHA) and subtalar vertical angle (SVA) were determined on WBCT, while the mechanical tiba – (mTA) and mechanical tibiofemoral angle (mTFA) were measured on full leg radiographs. Results: In patients with ankle OA, a hindfoot valgus deformity was associated with a significantly higher mean varus alignment of the knee (mTFA = -1.8°±2.1; mTAx= -4.3°±1.9) compared to a valgus alignment of the knee (mTFA = 0.3°±2.6; mTAx= -1.4°±2.2; P <0.001) in patients with a varus hindfoot (Fig1A, B). The opposite relation was found in patients without ankle OA (P <0.001). The SVA was significantly more orientated in valgus (mean=106.9°±8.0) for patients with a hindfoot valgus compared to a higher varus orientation (mean=89.3°±13.9) in patients with a hindfoot varus deformity (P <0.001). The same pattern was found in patients without ankle OA, but not significant (P >0.05). Conclusion: A valgus hindfoot deformity demonstrated a higher varus alignment of the knee when compared to patients with a hindfoot varus deformity, if ankle OA was present. The subtalar joint did not attain an overall compensatory correction towards the hindfoot deformity as opposed to a compensatory orientation of the tibia alignment. In clinical practice, these findings could improve the current understanding of both joint preserving as well as joint replacing procedures of the hindfoot and the knee.

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Modified Ankle-Hindfoot Alignment Radiological Evaluation Method and Application in the Flatfeet

Foot & Ankle Orthopaedics ◽

10.1177/2473011420s00254 ◽

2020 ◽

Vol 5 (4) ◽

pp. 2473011420S0025

Author(s):

Zhao Hong-Mou

Keyword(s):

Evaluation Method ◽

Weight Bearing ◽

Normal Group ◽

Flat Foot ◽

Hindfoot Alignment ◽

X Ray ◽

Normal People ◽

Significant Difference ◽

The Mean ◽

A Prospective Study

Category: Hindfoot Introduction/Purpose: Based on a prospective study, a new method of photographing and measuring of hindfoot alignment based on X-ray was proposed, and its reliability is verified, as well as its application in flatfeet. Methods: This study included 28 patients (40 feet) with flatfeet and 20 volunteers (40 feet) from January to December in 2018. The shooting frame, designed by our team, has been used to take the hindfoot alignment view at 10°, 15°, 20°, 25°, 30° respectively. Our modified tibio-hindfoot angles (THA) at standard Saltzman position (shooting at 20°) were evaluated, and the consistency were compared with the van Dijk method and the modified van Dijk method, and compared with weight-bearing CT. The visibility of tibiotalar space were evaluated in all shooting angles. The consistency of the modified THA method at different projection angles were evaluated. The angle of hindfoot valgus of flatfoot patients was measured with use of the modified THA method, and compared in different shooting angles. Results: The mean THA in standard Saltzman view in normal people were significantly differences between the three evaluation methods (P < 0.001). The results of modified THA method were significantly larger than those of Van Dijk method (P < 0.001) and modified Van Dijk method (P < 0.001). There was no significant difference between the results of modified THA method and the weight-bearing CT (P=0.605), and the intra- and inter-group consistency was the best in modified THA group. The tibiotalar space in the normal group were visible in all cases at 10°, 15°, 20°; and visible in some cases at 25°; and invisible in all cases at 30°. In the flatfoot group, the tibiotalar space were visible in all cases at 10°; and in some cases at 15° and 20°; and invisible in all cases at 25° and 30°. In the normal group, the modified THA was 4.84±1.81° at 10°, 4.96±1.77° at 15°, 4.94±2.04° at 20°. No significant difference was found between the three groups (P=0.616). In the flat foot group, the modified THA of 18 feet, which was visible at 10°, 15° and 20°, was 13.58±3.57° at 10°, 13.62±3.83° at 15° and 13.38±4.06° at 20°. There was no significant difference between the three groups (P=0.425). Conclusion: The modified THA evaluation method is simple to use and has high intra- and inter-group consistency. It can be used to evaluate hindfoot alignment. For patients with flatfeet, the 10° position view and modified THA measurement can be used to evaluate the hindfoot valgus conditions.

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Three-dimensional ultrasound for knee osteophyte depiction: a comparative study to computed tomography

International Journal of Computer Assisted Radiology and Surgery ◽

10.1007/s11548-021-02456-4 ◽

2021 ◽

Author(s):

Valeria Vendries ◽

Tamas Ungi ◽

Jordan Harry ◽

Manuela Kunz ◽

Jana Podlipská ◽

...

Keyword(s):

Computed Tomography ◽

Automatic Segmentation ◽

Three Dimensional ◽

3D Ultrasound ◽

Surgical Interventions ◽

Structured Light Scanner ◽

Joint Surfaces ◽

Operative Planning ◽

Rms Error ◽

Tissue Characteristics

Abstract Purpose Osteophytes are common radiographic markers of osteoarthritis. However, they are not accurately depicted using conventional imaging, thus hampering surgical interventions that rely on pre-operative images. Studies have shown that ultrasound (US) is promising at detecting osteophytes and monitoring the progression of osteoarthritis. Furthermore, three-dimensional (3D) ultrasound reconstructions may offer a means to quantify osteophytes. The purpose of this study was to compare the accuracy of osteophyte depiction in the knee joint between 3D US and conventional computed tomography (CT). Methods Eleven human cadaveric knees were pre-screened for the presence of osteophytes. Three osteoarthritic knees were selected, and then, 3D US and CT images were obtained, segmented, and digitally reconstructed in 3D. After dissection, high-resolution structured light scanner (SLS) images of the joint surfaces were obtained. Surface matching and root mean square (RMS) error analyses of surface distances were performed to assess the accuracy of each modality in capturing osteophytes. The RMS errors were compared between 3D US, CT and SLS models. Results Average RMS error comparisons for 3D US versus SLS and CT versus SLS models were 0.87 mm ± 0.33 mm (average ± standard deviation) and 0.95 mm ± 0.32 mm, respectively. No statistical difference was found between 3D US and CT. Comparative observations of imaging modalities suggested that 3D US better depicted osteophytes with cartilage and fibrocartilage tissue characteristics compared to CT. Conclusion Using 3D US can improve the depiction of osteophytes with a cartilaginous portion compared to CT. It can also provide useful information about the presence and extent of osteophytes. Whilst algorithm improvements for automatic segmentation and registration of US are needed to provide a more robust investigation of osteophyte depiction accuracy, this investigation puts forward the potential application for 3D US in routine diagnostic evaluations and pre-operative planning of osteoarthritis.

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A computer-based approach for developing linamarase inhibitory agents

Physical Sciences Reviews ◽

10.1515/psr-2019-0098 ◽

2020 ◽

Vol 5 (7) ◽

Author(s):

Lucas Paul ◽

Celestin N. Mudogo ◽

Kelvin M. Mtei ◽

Revocatus L. Machunda ◽

Fidele Ntie-Kang

Keyword(s):

Structure Elucidation ◽

Three Dimensional ◽

Data Bank ◽

Competitive Inhibitor ◽

Industrial Applications ◽

Dimensional Structure ◽

Full Understanding ◽

The Poor ◽

Computer Based ◽

Inhibitory Agents

AbstractCassava is a strategic crop, especially for developing countries. However, the presence of cyanogenic compounds in cassava products limits the proper nutrients utilization. Due to the poor availability of structure discovery and elucidation in the Protein Data Bank is limiting the full understanding of the enzyme, how to inhibit it and applications in different fields. There is a need to solve the three-dimensional structure (3-D) of linamarase from cassava. The structural elucidation will allow the development of a competitive inhibitor and various industrial applications of the enzyme. The goal of this review is to summarize and present the available 3-D modeling structure of linamarase enzyme using different computational strategies. This approach could help in determining the structure of linamarase and later guide the structure elucidation in silico and experimentally.

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