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Tag Archives: pedCAT

The pedCAT Weight-Bearing CT Scan Put CurveBeam a Step Ahead of the Competition

It’s hard to forget about your feet—socks and shoes, not to mention pain at the end of a long workday. As the foundation of your mobility, foot health is vital to overall health. But foot health involves more than just keeping them clean and dry. It is vital to wear properly fitted shoes—custom insoles (avoid flimsy over-the-counter insoles) and supportive sandals are also a good idea. In fact, feet are so important to us that they even get their own specialists.

An expert in the field of podiatry, Dr. Kyle Kinmon of Boca Raton, FL recently shared some advice on WPTV for maintaining optimal foot health. Kinmon used part of his television segment to introduce viewers to the latest pedCAT technology from CurveBeam: a weight-bearing CT scan for diagnosing foot and ankle issues.

In fact, Kinmon’s office is the first in South Florida to offer a 3D foot scanner, the pedCAT technology from CurveBeam. Introducing the tool to TV viewers on WPTV, Kinmon said, “This is called the pedCAT. It’s the newest technology in the world of foot and ankle. It’s a weight-bearing CT scanner that, in 19 seconds, will provide us with every possible image you could want to see in the foot and ankle.”

To learn more about Dr. Kinmon’s practice, please visit www.certifiedfoot.com.

Dr. Kinmon, a fellow of the American College of Foot and Ankle Surgeons, has contributed to research in the field of podiatry with many peer-reviewed publications, including an award-winning article in the Journal of the American Podiatric Medical Association and an article on pediatric flat foot for New Balance shoe company’s health line. Kinmon is also the Founding Director of Residency Training for Bethesda Memorial Hospital’s three-year Podiatric Surgical Residency Program, further supporting residents in surgery at three area residency training programs.

While Kinmon is highly trained in foot and ankle surgery, he always considers surgery the last resort. In the vast majority of cases, surgery is not required, and the condition is resolved using conservative treatment alone. Still, even for someone as skilled as Dr. Kinmon, diagnosing foot and ankle issues can be challenging.

The pedCAT’s bilateral, weight-bearing 3D views of the foot and ankle give specialists the information they need to create comprehensive treatment plans. Its compact (4’ x 5’), ultra-low dose (2-5 micro Sieverts per scan) CT imagine system plugs into the wall and is ideal for orthopedic and podiatric clinics. Scan time is one minute, and the pedCAT automatically generates all standard X-ray views in addition to the full CT volume. The pedCAT is PACS/DICOM compatible and supports DICOM modality worklist (HIS/RIS) and PACS integration.

One can definitely understand why Kinmon was excited to share the news about pedCAT with television viewers. With the pedCAT from CurveBeam, his job is now a lot easier and his diagnoses more accurate than ever.

To learn more about the exciting new pedCat from CurveBeam, visit http://curvebeam.com/products/pedcat today!

CurveBeam’s pedCAT Imaging System Exhibited at CIRMS Annual Meeting

The Council on Ionizing Radiation Measurements and Standards (CIRMS) 25th Annual Meeting in Gaithersburg, MD will showcase new cutting edge technologies touching on the fundamental aspects of radiation measurements and focusing on the theme of ‘Past, Present, and Future’. The dynamic and diverse aspects of the importance of measurements and standards in this area will be addressed by international experts from academia, industry, and government. These experts will examine radiation protection, industrial applications and radiation effects, medical applications, homeland security, and other related areas.

CurveBeam is pleased to announce we will be participating. A CurveBeam engineer will be presenting on Tuesday, March 28 during “Breakout Session III: Real Time Imaging for Orthopedic Applications.” Her talk is titled “Why Cone Beam CT Can Make 3D the Standard of Care in Extremity Imaging.” With Cone Beam CT imaging, CurveBeam is revolutionizing the way specialists diagnose and create comprehensive treatment plans for podiatric and orthopedic issues.

The core team behind CurveBeam pioneered Cone Beam CT imaging technology for the dental specialties. The introduction of point-of-care Cone Beam CT imaging revolutionized the industry and ushered in the advent of custom dental implants and improved practices in orthodontics and oral surgery. Today, Cone Beam CT scans are virtually the standard of care for advanced oral surgery treatment planning. In the same way, CurveBeam hopes to contribute to the improvement of the orthopedic and podiatric specialties worldwide through their new product pedCAT.

One of the goals of the CIRMS Annual Meeting is to get input from audience participants on the need for developing a 3D real-time imaging tool for evaluating orthotics inside shoes with the patient in a weight bearing position. Once the orthotic has been made, an image of the patient can be taken in the weight bearing position, with the patient standing in his/her shoes with the new orthotic installed in the shoe. This type of analysis could be used to evaluate if the orthotic does what it is meant to do. The 3D weight bearing images can provide information about specific bone alignment issues using the new orthotics. The images can also reveal if the new orthotic is providing the expected amount of correction without compromising other foot anatomical issues, and if the spacing between the major foot joints is affected by the new orthotic.

CurveBeams’s pedCAT system allows specialists a unique bilateral, weight bearing 3-dimensional view of the foot and ankle to fully diagnose and create comprehensive treatment plans. The pedCAT is a compact, ultra-low dose CT imaging system ideal for orthopedic and podiatric clinics. Patients benefit from the convenience of point-of-care advanced diagnostic imaging. Scan time is one minute, and the pedCAT automatically generates all standard X-Ray views in addition to the full CT volume. Depending on the scan protocol, the patient is exposed to 2 – 5 micro Sieverts per scan. That’s about the same as a plain X-Ray study of the foot and ankle, and less than the average daily background radiation a U.S. resident is exposed to.
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To learn more about the CurveBeam pedCAT Imaging System and how it is revolutionizing the orthopedic and podiatric fields, visit curvebeam.com, or talk with our team at the CIRMS 25th Annual Meeting, March 27th to March 29th in Gaithersburg.

CBCT Technology is Increasingly Used by Orthopedists and Podiatrists

Cone beam computed topography (CBCT) systems are becoming popular with orthopedists and podiatrists because they quickly provide high-quality, low-dose, 3D imaging of musculoskeletal conditions. Dentists and podiatrists have been using CBCT technology for years, but the pedCAT by CurveBeam is designed specifically for extremities: especially knees, ankles, and feet. This compact, affordable unit gives specialists bilateral, weight-bearing 3D views of the foot and ankle, allowing physicians to create comprehensive treatment plans. In a Radiology Today article titled “Imaging in the Extremities,” Beth W. Orenstein, a freelance medical writer, examines this new technology.

There are a number of advantages to these new compact CBCT units. First, they have a larger area detector by which to image the patient in a single rotation, rather than taking many slices as with a tradition CT scanner. This feature eases system operation and reduces scan time. The pedCAT, for example, scans a patient in about one minute. Second, CBCT units can be located outside radiology departments, since they typically don’t require a lead-lined room or a special power source. Third, providers will find that CBCT positively impacts their practice, with improved diagnostic capabilities, streamlined workflow, and greater productivity. Finally, patients benefit with an easy-access unit that provides same-day results from a single brief visit.

CBCT provides other benefits to orthopedists and podiatrists, as well, such as the ability to produce load-bearing images. Load-bearing images of extremities, such as feet and ankles, may reveal alignment abnormalities that a conventional CT scan might miss. And CBCT offers improved spatial resolution over other methods, such as traditional CT scans or X-rays. One of the biggest benefits, though, is the transmission of a far smaller radiation dose. The tube current on a conventional CT scan typically ranges between 50 mA and 300 mA, and even an ultralow-dose setting would be between 20 mA and 60 mA. CurveBeam’s pedCAT, by contrast, has a fixed tube current of just 3mA, and the patient is exposed to 2 to 5 micro Sieverts per scan—less than the average background radiation a U.S. resident experiences daily.

Of course, there are also several challenges in adopting CPCT technology. For example, since CBCT uses a completely different image acquisition technology, comparing scans with conventional CT is difficult. The lack of dose and image quality assessment standards for CBCT limits accreditation. And since a unit like the pedCAT automatically generates all standard X-Ray views in addition to the full CT volume, many orthopedists and podiatrists feel they can interpret the images themselves in-house. In fact, some radiologists fear that point-of-care units could negatively impact their role as specialists. But other radiologists argue that the sophistication required in interpreting CT scan results will keep their expert services in demand.

In the future, CBCT units may even be used in emergency departments, as well, since the unit takes up so little space. The pedCAT’s footprint, for example, is about four feet by five feet. This means a CPCT scanner could be easily relocated where needed since it is relatively lightweight and mobile.

Read ““Imaging in the Extremities” by Beth W. Orenstein here: http://www.radiologytoday.net/archive/rt0317p16.shtml

The Hospital for Special Surgery Utilization of pedCAT

The Hospital for Special Surgery (HSS) located in Manhattan is ranked as the #1 hospital for orthopedics by the prestigious US News and World Report (2016-2017). And when the surgeons and clinicians at this elite medical institution need to make a proper foot and ankle diagnosis, they rely on CurveBeam’s revolutionary pedCAT system for fast and accurate 3D imaging.

Assessing the root cause of a patient’s pain is essential for developing a comprehensive treatment plan. At HSS, this evaluation process begins with an interview so that specialists can learn a patient’s unique history and obtain information regarding the primary care physician’s prognosis. Then the patient steps into the pedCAT scanner, where expert radiologists can conduct foot and ankle imaging faster than X-rays and CT scans, resulting in fewer hospital trips and significantly reduced exposure to radiation. The pedCAT system delivers the highest quality images and robust data, allowing physicians to make the most accurate diagnosis of the malady, and guiding the surgeon in the operating room for a superior treatment outcome. Watch below and visit curvebeam.com to learn more about the pedCAT.

 

Curvebeam’s Booth Is a Must-See at RSNA 2016!

In just a little over a week, many of the greatest minds and innovators in radiology will convene in Chicago for RSNA 2016, and we at CurveBeam are proud to have our talented and skilled team there representing us. Over the course of the conference, there will be groundbreaking research presented, technological advances displayed and educational classes offered. In the heart of it all, our booth will be featuring some incredible innovations – proving once again that CurveBeam is continuing to find new ways to push the boundaries of our field.

Our core team pioneered Cone Beam CT imaging technology for the dental and ENT specialties. The ability to provide point-of-care imaging revolutionized these industries and allowed not only for improved care, but for the possibility of custom dental implants. Now we are taking that same breakthrough technology and adapting it to the orthopedic field, and we are proud to introduce the results of our efforts at this year’s RSNA. Here are our top three reasons why you can’t afford to miss the CurveBeam booth this year:

  1. See the LineUp

We will  unveil the prototype for the LineUP, a bilateral weight-bearing Cone Beam CT imaging system for the knees and lower extremities. It will not only plugs into a standard wall outlet, but will also be self-shielded and will complete a scan in under a minute. While the technology is still investigational only, it is PACS/ DICOM compliant and is sure to revolutionize the way orthopedic clinics approach radiology.

 

  1. Experience InReach

While the LineUp is certainly fast, the InReach completes scans of the hand wrist, forearm, elbow and extremities in under 20 seconds flat. We designed InReach technology to bring the idea of point-of-care extremity CT imaging  to upper extremity specialists. While it is also still investigational technology, the progress we’ve made toward this goal is worth coming to see.

 

  1. Discover TALAS

One of the most crucial elements of orthopedic surgical planning is the precise pre-operative measurement of hindfoot realignment. TALAS is a tool that makes the process not only smoother, but more accurate and precise. It is a semi-automated hindfoot alignment measurement device that has been adapted for weight-bearing CT. Come check it out for yourself, and discover the potential TALAS has to one day be a true game-changer in the field.

“We are tremendously excited to share our recent research and development efforts with the global radiology community,” says CurveBeam President and CEO Arun Singh. RSNA is an opportunity to share and learn together as a community and we are thrilled to be a part of that experience. Feel free to come by and discover our innovative new technology. If you want to learn more before seeing our products in person, visit CurveBeam.com. We hope to see you soon at RSNA 2016!

Weightbearing CT Imaging Methodology with pedCAT by CurveBeam

 
Three-dimensional weight-bearing computed tomography (CT) can be a powerful diagnostic tool, typically used when more information is necessary (e.g. intra-articular fractures, occult fractures and small bone tumors). Unlike conventional CT, which has a fan-shaped X-ray beam, modalities in the pedCAT created by CurveBeam have a cone-shaped X-ray beam. In a Podiatry Today’s article titled “Current Concepts With Weight bearing CT”, Dr. Albert V. Armstrong Jr., dean of the Barry University School of Podiatric Medicine, reviewed three independent studies that examined the efficacy of the technology.

In the first, Yoshioka and colleagues studied 10 patients with posterior tibial tendon dysfunction and 10 control patients, using weight-bearing and non-weight-bearing CT.1 The authors noted that the study clarified part of the clinical condition of the forefoot in flatfoot deformity, saying this may be applicable in basic research of the staging advancement and sub-stage classification of flatfoot.

In the second study, Krähenbühl and coworkers used weightbearing CT to determine the subtalar vertical angle in a study of 40 patients with osteoarthritis and 20 control patients.2 The study authors found that measuring the subtalar vertical angle was a reliable and consistent method to assess the varus/valgus configuration of the posterior facet of the subtalar joint.

In the final study, Geng and colleagues studied weightbearing and non-weightbearing CT scans of 10 patients with hallux valgus and 10 control patients, reconstructing 3D models for the first metatarsal and the medial cuneiform.3 Researchers noted the study furthers an understanding of the physiological and pathological mobility of the first metatarsocuneiform joint.

Weightbearing CT is a safe imaging modality with low radiation exposure that can provide superior images in comparison to conventional CT, as evidenced by the multiple studies. Weightbearing CT can enhance biomechanical evaluation, preoperative planning, postoperative evaluation, wound management, sports medicine, treatment of arthritic conditions (especially degenerative joint disease) and trauma (especially when looking for occult or hairline fractures). It is a promising and up and coming imaging method to replace traditional CT technology.

Cone beam CT allows clinicians to obtain an image of a volume of tissue in one circumferential pass instead of having to take multiple slices with multiple exposures. This leads directly to reduced radiation exposure for patients. Studies indicate, in the example of a bilateral scan of a foot, the pedCAT machine exposes patients to one third the amount of radiation as traditional methods. Another great feature of weight-bearing CT is the ability to perform bilateral scans. One can also view the same patient with the view of the the soft tissue structures removed, leading to increasingly accurate prognosis. In addition, the pedCAT is an excellent tool to illustrate visually to a patient exactly where a bunion, for example, is located underneath the soft tissue. The generated visual displays are much easier to understand for non-trained individuals.

Performing actual weightbearing examinations is possible through pedCAT, a main advantage of the machine. In a specific instance, a podiatrist can view a foot supporting weight, viewing the 3D image and the accompanying 2D images in the sagittal, axial (transverse) and coronal (frontal) planes. This would allow the physician to observe the appendage in its most natural state, allowing a more precise diagnosis of problems.

Read “Current Concepts With Weightbearing CT” by Dr. Albert V. Armstrong Jr. here: http://www.podiatrytoday.com/current-concepts-weightbearing-ct

 

CurveBeam Announces Development of Extremity CT System for Knee

A new orthopedic CT system promises to improve the standard of care for knee imaging. On the CurveBeam LineUp, patients are scanned while standing upright and fully weight bearing.

CurveBeam LineUP
CurveBeam LineUP provides bilataral weight bearing CT imaging of the knees and lower extremities.

Traditional CT and MR images are acquired in a non-weight bearing position, leading to “missed diagnoses of meniscal damage,” according to Dr. Neil Segal, who has been overseeing research efforts using a LineUp prototype, first at the University of Iowa and currently at the University of Kansas.

Neil Segal, MD
Neil Segal, MD

Although plain radiographs can be acquired while the patient is in a full weight-bearing position, the optimal degree of knee flexion and X-Ray beam tilt to best visualize the joint surface is person specific.

“Difficulty in reproducing the same view of the joint over time impairs ability to detect joint disease, and the 2D nature of radiographs makes these images of overlapping bony anatomy very insensitive for detecting abnormalities until there is advanced joint damage,” Dr. Segal said.

The LineUp was developed by CurveBeam, a Pennsylvania-based company that specializes in extremity cone beam CT systems for orthopedics. CurveBeam anticipates it will submit an application for and receive FDA 510(k) clearance for the LineUp in 2017. The LineUp will be on display at RSNA at Booth #8008 in the North Hall.

CurveBeam introduced the pedCAT, a bilateral weight bearing CT system dedicated to the foot and ankle, in 2012. Since then, the device has been added to the imaging services of hospital foot & ankle sections, orthopedic clinics and podiatry offices.

Like the pedCAT, the LineUp will provide isotropic, three-dimensional volumes of the anatomy with a high resolution output of between 0.2 mm and 0.3 mm slices. The LineUp will be the only cone beam CT system that can provide bilateral, weight bearing scans.

A study led by Dr. Segal focused on osteophytes, one structure

linked to pain in people with knee osteoarthritis. Knees of community-dwelling adults with knee OA were imaged with MRI (reference), fixed-flexion radiographs, and weight bearing CT. The sensitivity and accuracy for detecting osteophytes and subchondral cysts were higher with weight bearing CT imaging in comparison to fixed-flexion radiographs. The study was published in the August 2016 issue of the Journal of Orthopedic Research.

“Clinically, this is a highly meaningful improvement,” Dr. Segal said. “It suggests that weight-bearing CT could replace radiographs as the recommended means of assessing knee OA. This advancement is even more significant given that it was made without significantly increasing the radiation dose (0.01 mSv for SCT vs. 0.005–0.102 mSv for a series of knee radiographs).”

Another research effort led by Dr. Segal indicates weight-bearing CT arthrography studies can provide outstanding delineation of articular cartilage with better differentiation between cartilage and subchondral bone then MRI studies, while also visualizing the cruciate ligaments. In knees with osteoarthritis, meniscal tears not visualized on MRI were detectable on weight-bearing CT.

“Thus, we found that some potential advantages of weight-bearing CT over non-weight-bearing MRI/MRA include 3D measures of meniscal position, detection of pathology not detected in unloaded positions, and ability to bear weight in a functional position, thus better recreating the magnitude of body weight and muscle forces acting around the knee during usual standing,” Dr. Segal said.

CurveBeam CT Imaging Technology is Right On Point

Ballet is an art of extremes. As such, the risk factors are high among dancers for developing chronic injury and weakened tissues throughout the lower half of their bodies. About 60% of ballet injuries affect the legs, hips, ankles or feet. Lateral ankle sprains and Posterior Ankle Impingement Syndrome, or the pinching sensation felt during repeated floor or barre work as the heel bone comes into contact with the talus bone, are chief among them.

By the age of 12, ballet dancers are generally considered ready to begin learning the en pointe technique which utilizes the unnatural convergence of the tibia, talus, and calcaneus to lock the ankles in place.

releve2
pedCAT weight bearing CT scan of a ballerina en pointe.

While we do know this position may facilitate injury, prior to the advent of advanced CT imaging podiatrists had no method of accurately determining the exact anatomical position of either bones or tissue in this position.

CurveBeam, founded in 2009, designs and manufactures Cone Beam CT imaging equipment for the orthopedic and podiatric specialties. In 2012 CurveBeam’s pedCAT system received official clearance from the FDA, and in 2013, CE Mark approval. With the implementation of tools such as the pedCAT and CubeVue, CurveBeam’s custom visualization software, researchers finally have the capability to help ballet teachers better understand the demands of this position before introducing it to young students.

en pointe sag
pedCAT weight bearing CT scan of a ballerina en pointe

Pointe technique, when examined through an advanced imaging system, reveals the posterior portion of the talus resides beyond its articular surface, while the posterior portion of the tibia’s articular surface leaves the articular surface of the dome to rest on the posterior talus. The three bones converge. According to Dr. Jeffrey A. Russell, Ph.D, A.T., FIADMS:

“Attaining the full en pointe position requires contributions from movements between the bones in the foot. Examples of such movements include sliding between the talus and the navicular, the navicular and the medial cuneiform, and the medial cuneiform and the first metatarsal. These small increments of motion combine to provide approximately 30% of the plantar flexion range.”

pedCAT weight bearing CT ballet
pedCAT weight bearing CT scan of a ballet dancer en releve.

“In addition, it is noteworthy that the talus shifts slightly anterior from under the tibia as the ankle-foot complex moves en pointe. This subtlety arises because the converging tibia, talus, and calcaneus form a fulcrum that applies an anterior force to the talus, somewhat like a watermelon seed being squeezed from between one’s thumb and forefinger.”

Recently, Dr. Russell took to an advanced open MR scanner to review the upright and weight bearing position of uninjured ankles in six university-level dancers who had been dancing for an average of 13 years, and dancing en pointe for an average of seven years.

“All exhibited several traits in their ankle MRIs: the posterior portion of the articular surface of the tibia rested on a nonarticular surface of the posterior talus; the synovial sheaths of the flexor and fibularis tendons collected fluid; Kager’s fat pad was impinged by the posterior tibial plafond; and small ganglion cysts were apparent in one or more spots around the ankle and proximal foot.”

pedCAT weight bearing CT ballet
pedCAT weight bearing CT scan of a ballet dancer en releve

It’s an interesting find, and begs the question: do these conditions increase the likelihood of ballet dancers developing ankle osteochondritis or osteoarthritis?

Not only do advanced imaging systems such as the CurveBeam pedCAT – which was not used in this particular study – reveal the bones’ proper anatomic alignment, but they also enable a close investigation of cartilage quality, which isn’t possible with traditional MR imaging. Bilateral, weight bearing three-dimensional views of the foot and ankle are therefore the most cogent means for specialists to create comprehensive treatment regimens and surgeons to better visualize their surgery plans for better operation outcomes.

Most importantly, however, is Dr. Russell’s recent study confirms the use of orthopedic imaging to examine pointe dancers’ ankles in detail will only continue to offer more insight into the demands placed on the ankle by dancing in this way, ultimately leading to safer instruction, more accurate treatment of injuries, and faster recovery times.

CurveBeam Announces First pedCAT Installation at an Accredited College of Podiatric Medicine

CurveBeam is proud to announce the installation of a pedCAT cone beam CT imaging system at Kent State University College of Podiatric Medicine.

Kent State is the first member of the American Association of Colleges of Podiatric Medicine to acquire weight bearing CT imaging technology.

“Kent State University is proud to be the first facility in the Northeast Ohio region to provide this ‘state- of-the-art” imaging modality,” said Dr. Allan Boike, Dean & Professor of Foot & Ankle Surgery at KSUCPM. “The CurveBeam pedCAT will allow the college to improve the foot and ankle health of the community while providing the highest quality education for our students and research opportunities for our faculty and residents.”

The pedCAT is the only cone beam CT imaging system that allows for bilateral, weight bearing CT images of the foot & ankle. Due to its compact size and low radiation exposure, the pedCAT is an an ideal solution for CT imaging at the podiatric point-of-care. Recent articles in orthopedic journals demonstrate weight bearing CT imaging is a valuable research tool that is shedding new light on even our basic understanding of foot & ankle biomechanics and deformities.

“Our initial euphoria in acquiring the pedCAT weight-bearing cone beam CT has only been eclipsed by actually getting to use it first-hand,” said Dr. Lawrence Osher, Director of the Radiology Department. “Simply put, this is an utterly amazing tool in the podiatric diagnostic and research armamentarium.  The ability to do 3D and multi-planar reconstructions on a weight-bearing foot and ankle, coupled with the prospect of marrying structure and function, opens up a seemingly endless array of research opportunities.  Bounded only by our creativity, we at KSUCPM look forward to adding significantly to the pool of knowledge in the medical literature.”

The pedCAT was funded through a research grant from the Ohio College of Podiatric Medicine (OCPM) Foundation, which was established to promote podiatric medical education and research.

“Dean Boike is to be commended for his foresight in procuring this advanced apparatus which further enables the College to maintain and expand its competitive edge in podiatric medical education,” said Dr. David Nicolanti, Executive Director of the OCPM Foundation. “In addition, this weight bearing CT imaging system provides a basis for enhancing collaboration between the College and foot and ankle specialists, from all medical stratums throughout the state of Ohio and the encompassing region.”

The College has a number of weight bearing CT research initiatives planned.

The pedCAT is located at the Cleveland Foot and Ankle Clinic’s midtown office at 7000 Euclid Ave in Cleveland. Weight bearing CT services will be offered to the clinic’s patients.

Need Bunion Surgery? A Weight Bearing CT Scan Could Help You Decide

When a patient appears to have a bunion, a physician typically orders traditional foot X-Rays as part of the clinical evaluation. The X-Rays capture three views of the foot- dorsoplantar, medial oblique, and lateral. But is this enough information to understand complex, three-dimensional object such as the foot? 

A growing number of foot & ankle specialists are advocating that there may be better way to evaluate this common deformity.

“Weight bearing computed tomography scans are beginning to take our understanding to the next level,” Dr. Paul Dayton, DPM, of Des Moines, IA, said in a roundtable discussion on bunions published in the Foot & Ankle Specialist academic journal. “Once you see the connection between coronal rotation and what we have traditionally evaluated on AP radiographs, it opens up a whole new understanding.”

On X-Rays, physicians have to “mentally interpolate” the valgus component of the bunion because they do not adequately capture the frontal plane, said Dr. Robert Weinstein, DPM, FACFAS, of Atlanta, explained in a CurveBeam case study.  

“Since the condition is a tri-plane deformity, we need to understand all of the components and their angular values contributing to the deformity,” Weinstein said. “Better deformity analysis leads to better pre-operative planning, surgical execution, and post-operative results.”

The new data on the coronal position is “exciting” because it explains so many of foot and ankle specialists’ previous questions, Dayton said.  

Weight bearing CT imaging also allows for evaluating deformities that involve external rotation. Rotation of one or more metatarsals, including displacement of the sesamoids, cannot be clearly seen in standard foot X-ray imaging. The lack of the weight-bearing aspect in traditional medical CT imaging means the physician cannot evaluate displacement and rotation under load.

Hallux Valgus Blog Post Image 1
One component of the deformity that is seldom quantified is external rotation, or frontal plane deviation. The presence of rotation of the hallux implies a more complex deformity. A very careful assessment of the first metatarsophalangeal joint architecture, including sesamoid position, their condition, and erosion or flattening of the crista on the inferior first metatarsal head is essential.

It has long been known that in hallux valgus or bunions the relationship between the metatarsal head and the sesamoids is altered,” Andy Goldberg, MD, MBBS, FRCS (TR and Orth), of Stanmore, United Kingdom, told Lower Extremity Review magazine. he said. “The sesamoid bones should sit underneath the metatarsal head, while in hallux valgus the big toe drifts off the sesamoids and the tip of the big toe points outwards. But our research has shown that in many cases the cartilage is worn, which in essence is localized arthritis, and we believe that this could affect the outcome of surgery.”

rotated first met and sesamoids

CubeVue, the pedCAT weight bearing CT imaging system’s custom visualization software, allows physicians to create oblique and frontal-plane images of varying angles and thicknesses from the weight bearing CT data.
CubeVue, the pedCAT weight bearing CT imaging system’s custom visualization software, allows physicians to create oblique and frontal-plane images of varying angles and thicknesses from the weight bearing CT data.

Weight bearing CT images could have an impact on the technique a physician selects to repair a bunion, Dr. Dayton said.

“The knowledge that the sesamoids can be in normal position medial and lateral to the crista yet look dislocated on the AP X-ray because of pronation completely changes our mindset about the need for capsular balancing,” Dayton said. “We can see that in those cases supination corrects the deformity.”